review of the phase 1a remedial …well survey conducte durind g th e phase 1a investigation...
TRANSCRIPT
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION I
JCHNF KENNEDY FEDERAL BUILDING ONE CONGRESS STREET
BOSTON MASSACHUSETTS 02203-2211
CERTIFIED MAIL RECEIPT RETURN REQUESTED
January 21 1994 Superfund Records Center SITE olt3 Y ir Tft Ki f Lot BREAK 51 J
OTHER OBennington RIFS Settling Parties Mr Stuart Kurd Project Coordinator 205 South Street Bennington VT 05201
Subject Review of the Draft Phase 1A Remedial InvestigationFeasibility Study Initial Site Characterization Report Bennington Landfill Superfund Site Bennington Vermont
Dear Mr Kurd
The United States Environmental Protection Agency (EPA) has completed the review of the documents entitled Draft Phase 1A Remedial Investigation Feasibility Study Initial Site Characterization Report Bennington Landfill Superfund Site Bennington Vermont (Characterization Report) This document was prepared by McLarenHart (MHs) on behalf of the Settling Parties (SPs) and submitted to EPA on October 18 1993 pursuant to the Administrative Order by Consent (Order) Docket No 1-91shy1093 effective July 8 1991
EPA Approves with Conditions the Initial Site Characterization Report for the Bennington Superfund Site pursuant to Paragraph 27 (b) of the Order EPA requires that the Settling Parties revise this Characterization Report to incorporate the comments attached to this letter and the results of the Phase IB with the Draft RI Report
Please note that this letter is not an approval of the Phase IB Work Plan EPAs review of this document has identified a number of datagaps which are specified in this comment letter The data gaps must be addressed in a revision to the Phase IB Work Plan and submitted to EPA on February 28 1994
The overall format for the determination letter is as follows
1) Attachment I General and Summary Comments 2) Attachment II Page-specific Comments 3) Attachment III EPA Split Sample Comparison with Settling Parties Samoles
RlaquocyclraquodRcyclaquobtraquo Printed wtthSoyXUnol Ink on popr thai axu laquoIwa 75X rraquocycraquolaquod telaquof
If you would ]ike to set up a meeting to discuss these comments or if you have any questions please contact Indira Balkissoon at (617) 573-5768
Sincerely
Mary Jane ODonnell Section Chief ME amp VT Superfund Section
enclosures
cc Stan CorneilleVTDEC Geoff Seibeldemaximis tlndlra Balkisso6Ti7EPA Andy RaubvogelEPA
ATTACHMENT I GENERAL AND SUMMARY COMMENTS
I The Executive Surinary nus~ be revised to reflect the changes requested in these comments
2) Include the surnary map provided to EPA on December 28 1993 identifying residences and type of water supply along Houghton Lane Lots 891015 on Map 25 along Andre Lane 11121314 en Map 25 and on Autumn Acres Lots 1234567391011 and 12 on Map 26
3) Include a summary table of the results of the residential well survey conducted during the Phase 1A investigation (including EPA sample results )
4) The laboratory detection limits are not low enough to compare all test results to the necessary regulatory limits such as the Safe Drinking Water Regulations Maximum Contaminant Levels EPA concurs with the recommendation that confirmatory sampling of ground warer and analysis using methods with lower detection limits be performed
In addition the laboratory needs to be advised that the detection limits for vinyl chloride must be no greater than 1 parts per billion
5) The text states that the positive pesticide results except for DDT DDE and DDD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criterion for rejection was a percent difference between the reported results from the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results may underestimate the risk the Settling Parties must use the lower concentration from the primary and confirmatory analysis as a confirmed positive result
6) Some additional sampling must be collected to complete site characterization (delineate the extent of contamination)
Additional surface soilssediments sampling is required in the wetlands area south of the landfill to define the extent of the PCS contamination No data has been provided which delineates the areal extent of PCB detections to the south of the wetland along the 950 940 and 930 topographic contours
Further definition rf the source of PC3 contamination tc the wetland ares south of the landfill is necessary
Leachate seeps were observed during the first round of groundwater sampling at the toe and midslope positions of the TSS pile nurber 3 Leachate was observed flowing into the drainage which eventually empties into the wetlands area south of the landfill Leachate from this sludge pile rust be evaluated for PCBs and metals
Upon removal of the sludge piles soil samples must be collected from the locations within the footprint of the former pile locations
Samples of surface vater and sediment must be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for u-se irtrtbe risk assessment purposes
Sampling is required to determine the horizontal and vertical (areal) extent of contamination within the drainage pond area and determine whether or not the drainage pond is a source of contamination
Additional saturated soil sampling is required in the area east of the drainage pond in order to determine the extent of the PCB contamination in the northeastern direction
Some additional groundwater information is required to delineate the extent of the ground water contamination detected at B-6 and B-5 While flow may be diverted back into the landfill because of the drainage structures this may not be the case Also additional information is required to evaluate groundwater south of the old landfill (where elevated soil gas concentrations were detected) between B-l and B-2 north of B-l and north of B-5 A well should be installed west of the drainage pond to determine if the pond itself is acting as a source of VOCs to B-5 Field screening efforts using methods such as screened augers microwells or hydropunch to collect samples for field GC volatile scans may be considered if the Settling Parties think they would be successful in penetrating the gravel layers In this way the number of monitoring wells could be minimized
Provide a discussion of the source of the contmination detected in the B-7-3 and B-5
7
8)
9)
10)
11)
-
12)
A sarple rust be collected from piezcreter B-9 and screened for VQCs to verify that nc contamination exists at this location
The Phase 1A RI hurar health risk assessrient evaluated exposures to ambient air using only current land use scenarios and did not evaluate noncarcinogenic effects Ambient air risks for potential future residents must also be evaluated
EPA requires that a full round of additional surface water and ground water samples be collected and analyzed for full TCLTAL parameters during winter or early spring months to evaluate seasonal variability in contaminant concentrations
EPA requires that grcundwater information (water balance) be compiled from the Phase 1A and Phase IB field activities which will allow the Settling Parties and EPA to understand the relationship of the site to local and regional groundwater This information will aid in design and remedy selection
More information is required regarding the determination of a horizontal flow component to groundwater flow Horizonatal flow information will assist in the determination of whether or not controls are necessary
The ground water flow direction contours presented are not accurate especially within the landfill because they do not take into account the potential effect of the underdrain system the lateral drains and the diversion ditch on flow within the landfill Since the results of the landfill cover evaluation suggest that the cover is not impermeable given the radial locations of the leachate outbreaks the potential for mounding within the landfill is very high
Additional information is required to further evaluate the hydraulic system in and around the landfill prior to remedial design EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Four piezometers (not necessarily in the buried lagoon) are required to evaluate the effectiveness of the source control containment remedial action One of the objectives of a source control remedial action is to reduce or prevent to the extent practicable infiltration of surface andor groundwater into the waste areas and leaching of contaminants from the waste areas into the groundwater below
and downgradiert cf the vaste The piezometers will provide infornaticr regarding the extent to which the water table has been lowered The intent of such monitoring is to evaluate the effectiveness of the containinment system and establish the impact of such measures on the water table Water level measurements will be one of several factors in the evaluation the effectiveness of the remedial action in reducing contamination to clean up levels
13) The list of ARARs and Tc Be Considered (TBC) information developed in the Characterization Report appears to be complete and well-discussed with the exception of several minor issues which are noted below in the Page-Specific Comments section The potential ARARs for the site have been taken directly fror the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) While there is nothing wrong with this approach it is recommended that consideration be given to each ARAR (and TBC information) with regards to any field activities which nay be planned and the information which may be required relative to potential ARARs Because of the iterative nature of the RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
14) The Characterization Report does not address contaminant fate and transport as required by the Order The Characterization Report containing the results of both the Phase IA and Phase IB investigations must evaluate contaminant fate and transport Even at this stage some analysis is warranted so that decisions can be made on the Phase IB work plan For example an explanation is required to resolve the presence of trace levels of volatile organic compounds that have shown up in the bedrock wells B-7-3 and B-2-3 What do these trace levels indicate about the fate and transport of contamination from the landfill
15) The following issues should also be noted
The Characterization Report is a public document and must be easy to interpret With the public in mind revise the Characterization Report to include more legible diagrams figures summary tables and comprehensive tables to facilitate data interpretation For example it is almost impossible to read ground water elevations on Figure 5-3
Background values must be included on summary tables of analytical data Also all values greater than the background value should be highlighted
Include the letters to EPA describing changes to the work plan as an appendix to the Draft RI Report
7
Include this corrrrent leTirer in an appendix to the Draf t R Reoort
ATTACHMENT II PAGE-SPECIFIC COMMENTS
31 Executive Summary
Pace ii ^2 The second sentience states that the information collected in the Phase 1A is considered to be sufficient to characterize the nature and extent of contamination at the site1
Percve this statement EPA is authorized to make this aerermination based on the contents of the Draft RI Report
Page ii laquo14 Second Bullet The geologic description of the 100shy520 feet layer is over-simplified Isolated thin water bearing fnoist to saturated) sandy layers were encountered within the dense dry till during drilling Also at B3-3 the interpretation of buried valley deposits containing pre-glacial s-reara sediments or glacial outwash is described to exist between -he overlying till and weathered bedrock (saprolites) below is oversimplified Provide a more detailed description of these significant variations in the text
Page iii f2 Groundwater Quality First Bullet States impact from the landfill on the shallow water table is limited to a small onsite area immediately adjacent to and downgradient of -he landfill EPA will make a determination defining onsite based on the contents of the Draft RI Report
Page iii 52 Groundwater Quality Second Bullet Laboratory detection limits are too high for comparison to MCLs for some VQCs SVOCs PCBs and metals Therefore it is inappropriate to s~ate that the bedrock groundwater samples did not contain any compounds at concentrations which exceed MCLs Qualify this statement to reflect compounds for which this statement is applicable
Also delete the last sentence in this section The risk assessment makes the determination of whether or not groundwater from the landfill adversely affects the quality of groundwater in bedrock
Page iii K3 Surface Water First Bullet States that the surface water samples do not exceed the Clean Water Act Water Quality Criteria for chronic exposures (CWA WQC) Do the surface water samples exceed CWA WQC for acute exposures
Page iv laquoJ2 Soils and Sediment Second Bullet Knowledge of the horizontal and vertical extent of the PCB contamination is necessary for the feasibility study Revise this sentence to reflect that the full extent of contamination has not yet been adequately delineated to complete the baseline risk assessment at either the drainage pond nor the area south of the landfill
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
If you would ]ike to set up a meeting to discuss these comments or if you have any questions please contact Indira Balkissoon at (617) 573-5768
Sincerely
Mary Jane ODonnell Section Chief ME amp VT Superfund Section
enclosures
cc Stan CorneilleVTDEC Geoff Seibeldemaximis tlndlra Balkisso6Ti7EPA Andy RaubvogelEPA
ATTACHMENT I GENERAL AND SUMMARY COMMENTS
I The Executive Surinary nus~ be revised to reflect the changes requested in these comments
2) Include the surnary map provided to EPA on December 28 1993 identifying residences and type of water supply along Houghton Lane Lots 891015 on Map 25 along Andre Lane 11121314 en Map 25 and on Autumn Acres Lots 1234567391011 and 12 on Map 26
3) Include a summary table of the results of the residential well survey conducted during the Phase 1A investigation (including EPA sample results )
4) The laboratory detection limits are not low enough to compare all test results to the necessary regulatory limits such as the Safe Drinking Water Regulations Maximum Contaminant Levels EPA concurs with the recommendation that confirmatory sampling of ground warer and analysis using methods with lower detection limits be performed
In addition the laboratory needs to be advised that the detection limits for vinyl chloride must be no greater than 1 parts per billion
5) The text states that the positive pesticide results except for DDT DDE and DDD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criterion for rejection was a percent difference between the reported results from the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results may underestimate the risk the Settling Parties must use the lower concentration from the primary and confirmatory analysis as a confirmed positive result
6) Some additional sampling must be collected to complete site characterization (delineate the extent of contamination)
Additional surface soilssediments sampling is required in the wetlands area south of the landfill to define the extent of the PCS contamination No data has been provided which delineates the areal extent of PCB detections to the south of the wetland along the 950 940 and 930 topographic contours
Further definition rf the source of PC3 contamination tc the wetland ares south of the landfill is necessary
Leachate seeps were observed during the first round of groundwater sampling at the toe and midslope positions of the TSS pile nurber 3 Leachate was observed flowing into the drainage which eventually empties into the wetlands area south of the landfill Leachate from this sludge pile rust be evaluated for PCBs and metals
Upon removal of the sludge piles soil samples must be collected from the locations within the footprint of the former pile locations
Samples of surface vater and sediment must be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for u-se irtrtbe risk assessment purposes
Sampling is required to determine the horizontal and vertical (areal) extent of contamination within the drainage pond area and determine whether or not the drainage pond is a source of contamination
Additional saturated soil sampling is required in the area east of the drainage pond in order to determine the extent of the PCB contamination in the northeastern direction
Some additional groundwater information is required to delineate the extent of the ground water contamination detected at B-6 and B-5 While flow may be diverted back into the landfill because of the drainage structures this may not be the case Also additional information is required to evaluate groundwater south of the old landfill (where elevated soil gas concentrations were detected) between B-l and B-2 north of B-l and north of B-5 A well should be installed west of the drainage pond to determine if the pond itself is acting as a source of VOCs to B-5 Field screening efforts using methods such as screened augers microwells or hydropunch to collect samples for field GC volatile scans may be considered if the Settling Parties think they would be successful in penetrating the gravel layers In this way the number of monitoring wells could be minimized
Provide a discussion of the source of the contmination detected in the B-7-3 and B-5
7
8)
9)
10)
11)
-
12)
A sarple rust be collected from piezcreter B-9 and screened for VQCs to verify that nc contamination exists at this location
The Phase 1A RI hurar health risk assessrient evaluated exposures to ambient air using only current land use scenarios and did not evaluate noncarcinogenic effects Ambient air risks for potential future residents must also be evaluated
EPA requires that a full round of additional surface water and ground water samples be collected and analyzed for full TCLTAL parameters during winter or early spring months to evaluate seasonal variability in contaminant concentrations
EPA requires that grcundwater information (water balance) be compiled from the Phase 1A and Phase IB field activities which will allow the Settling Parties and EPA to understand the relationship of the site to local and regional groundwater This information will aid in design and remedy selection
More information is required regarding the determination of a horizontal flow component to groundwater flow Horizonatal flow information will assist in the determination of whether or not controls are necessary
The ground water flow direction contours presented are not accurate especially within the landfill because they do not take into account the potential effect of the underdrain system the lateral drains and the diversion ditch on flow within the landfill Since the results of the landfill cover evaluation suggest that the cover is not impermeable given the radial locations of the leachate outbreaks the potential for mounding within the landfill is very high
Additional information is required to further evaluate the hydraulic system in and around the landfill prior to remedial design EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Four piezometers (not necessarily in the buried lagoon) are required to evaluate the effectiveness of the source control containment remedial action One of the objectives of a source control remedial action is to reduce or prevent to the extent practicable infiltration of surface andor groundwater into the waste areas and leaching of contaminants from the waste areas into the groundwater below
and downgradiert cf the vaste The piezometers will provide infornaticr regarding the extent to which the water table has been lowered The intent of such monitoring is to evaluate the effectiveness of the containinment system and establish the impact of such measures on the water table Water level measurements will be one of several factors in the evaluation the effectiveness of the remedial action in reducing contamination to clean up levels
13) The list of ARARs and Tc Be Considered (TBC) information developed in the Characterization Report appears to be complete and well-discussed with the exception of several minor issues which are noted below in the Page-Specific Comments section The potential ARARs for the site have been taken directly fror the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) While there is nothing wrong with this approach it is recommended that consideration be given to each ARAR (and TBC information) with regards to any field activities which nay be planned and the information which may be required relative to potential ARARs Because of the iterative nature of the RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
14) The Characterization Report does not address contaminant fate and transport as required by the Order The Characterization Report containing the results of both the Phase IA and Phase IB investigations must evaluate contaminant fate and transport Even at this stage some analysis is warranted so that decisions can be made on the Phase IB work plan For example an explanation is required to resolve the presence of trace levels of volatile organic compounds that have shown up in the bedrock wells B-7-3 and B-2-3 What do these trace levels indicate about the fate and transport of contamination from the landfill
15) The following issues should also be noted
The Characterization Report is a public document and must be easy to interpret With the public in mind revise the Characterization Report to include more legible diagrams figures summary tables and comprehensive tables to facilitate data interpretation For example it is almost impossible to read ground water elevations on Figure 5-3
Background values must be included on summary tables of analytical data Also all values greater than the background value should be highlighted
Include the letters to EPA describing changes to the work plan as an appendix to the Draft RI Report
7
Include this corrrrent leTirer in an appendix to the Draf t R Reoort
ATTACHMENT II PAGE-SPECIFIC COMMENTS
31 Executive Summary
Pace ii ^2 The second sentience states that the information collected in the Phase 1A is considered to be sufficient to characterize the nature and extent of contamination at the site1
Percve this statement EPA is authorized to make this aerermination based on the contents of the Draft RI Report
Page ii laquo14 Second Bullet The geologic description of the 100shy520 feet layer is over-simplified Isolated thin water bearing fnoist to saturated) sandy layers were encountered within the dense dry till during drilling Also at B3-3 the interpretation of buried valley deposits containing pre-glacial s-reara sediments or glacial outwash is described to exist between -he overlying till and weathered bedrock (saprolites) below is oversimplified Provide a more detailed description of these significant variations in the text
Page iii f2 Groundwater Quality First Bullet States impact from the landfill on the shallow water table is limited to a small onsite area immediately adjacent to and downgradient of -he landfill EPA will make a determination defining onsite based on the contents of the Draft RI Report
Page iii 52 Groundwater Quality Second Bullet Laboratory detection limits are too high for comparison to MCLs for some VQCs SVOCs PCBs and metals Therefore it is inappropriate to s~ate that the bedrock groundwater samples did not contain any compounds at concentrations which exceed MCLs Qualify this statement to reflect compounds for which this statement is applicable
Also delete the last sentence in this section The risk assessment makes the determination of whether or not groundwater from the landfill adversely affects the quality of groundwater in bedrock
Page iii K3 Surface Water First Bullet States that the surface water samples do not exceed the Clean Water Act Water Quality Criteria for chronic exposures (CWA WQC) Do the surface water samples exceed CWA WQC for acute exposures
Page iv laquoJ2 Soils and Sediment Second Bullet Knowledge of the horizontal and vertical extent of the PCB contamination is necessary for the feasibility study Revise this sentence to reflect that the full extent of contamination has not yet been adequately delineated to complete the baseline risk assessment at either the drainage pond nor the area south of the landfill
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
ATTACHMENT I GENERAL AND SUMMARY COMMENTS
I The Executive Surinary nus~ be revised to reflect the changes requested in these comments
2) Include the surnary map provided to EPA on December 28 1993 identifying residences and type of water supply along Houghton Lane Lots 891015 on Map 25 along Andre Lane 11121314 en Map 25 and on Autumn Acres Lots 1234567391011 and 12 on Map 26
3) Include a summary table of the results of the residential well survey conducted during the Phase 1A investigation (including EPA sample results )
4) The laboratory detection limits are not low enough to compare all test results to the necessary regulatory limits such as the Safe Drinking Water Regulations Maximum Contaminant Levels EPA concurs with the recommendation that confirmatory sampling of ground warer and analysis using methods with lower detection limits be performed
In addition the laboratory needs to be advised that the detection limits for vinyl chloride must be no greater than 1 parts per billion
5) The text states that the positive pesticide results except for DDT DDE and DDD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criterion for rejection was a percent difference between the reported results from the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results may underestimate the risk the Settling Parties must use the lower concentration from the primary and confirmatory analysis as a confirmed positive result
6) Some additional sampling must be collected to complete site characterization (delineate the extent of contamination)
Additional surface soilssediments sampling is required in the wetlands area south of the landfill to define the extent of the PCS contamination No data has been provided which delineates the areal extent of PCB detections to the south of the wetland along the 950 940 and 930 topographic contours
Further definition rf the source of PC3 contamination tc the wetland ares south of the landfill is necessary
Leachate seeps were observed during the first round of groundwater sampling at the toe and midslope positions of the TSS pile nurber 3 Leachate was observed flowing into the drainage which eventually empties into the wetlands area south of the landfill Leachate from this sludge pile rust be evaluated for PCBs and metals
Upon removal of the sludge piles soil samples must be collected from the locations within the footprint of the former pile locations
Samples of surface vater and sediment must be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for u-se irtrtbe risk assessment purposes
Sampling is required to determine the horizontal and vertical (areal) extent of contamination within the drainage pond area and determine whether or not the drainage pond is a source of contamination
Additional saturated soil sampling is required in the area east of the drainage pond in order to determine the extent of the PCB contamination in the northeastern direction
Some additional groundwater information is required to delineate the extent of the ground water contamination detected at B-6 and B-5 While flow may be diverted back into the landfill because of the drainage structures this may not be the case Also additional information is required to evaluate groundwater south of the old landfill (where elevated soil gas concentrations were detected) between B-l and B-2 north of B-l and north of B-5 A well should be installed west of the drainage pond to determine if the pond itself is acting as a source of VOCs to B-5 Field screening efforts using methods such as screened augers microwells or hydropunch to collect samples for field GC volatile scans may be considered if the Settling Parties think they would be successful in penetrating the gravel layers In this way the number of monitoring wells could be minimized
Provide a discussion of the source of the contmination detected in the B-7-3 and B-5
7
8)
9)
10)
11)
-
12)
A sarple rust be collected from piezcreter B-9 and screened for VQCs to verify that nc contamination exists at this location
The Phase 1A RI hurar health risk assessrient evaluated exposures to ambient air using only current land use scenarios and did not evaluate noncarcinogenic effects Ambient air risks for potential future residents must also be evaluated
EPA requires that a full round of additional surface water and ground water samples be collected and analyzed for full TCLTAL parameters during winter or early spring months to evaluate seasonal variability in contaminant concentrations
EPA requires that grcundwater information (water balance) be compiled from the Phase 1A and Phase IB field activities which will allow the Settling Parties and EPA to understand the relationship of the site to local and regional groundwater This information will aid in design and remedy selection
More information is required regarding the determination of a horizontal flow component to groundwater flow Horizonatal flow information will assist in the determination of whether or not controls are necessary
The ground water flow direction contours presented are not accurate especially within the landfill because they do not take into account the potential effect of the underdrain system the lateral drains and the diversion ditch on flow within the landfill Since the results of the landfill cover evaluation suggest that the cover is not impermeable given the radial locations of the leachate outbreaks the potential for mounding within the landfill is very high
Additional information is required to further evaluate the hydraulic system in and around the landfill prior to remedial design EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Four piezometers (not necessarily in the buried lagoon) are required to evaluate the effectiveness of the source control containment remedial action One of the objectives of a source control remedial action is to reduce or prevent to the extent practicable infiltration of surface andor groundwater into the waste areas and leaching of contaminants from the waste areas into the groundwater below
and downgradiert cf the vaste The piezometers will provide infornaticr regarding the extent to which the water table has been lowered The intent of such monitoring is to evaluate the effectiveness of the containinment system and establish the impact of such measures on the water table Water level measurements will be one of several factors in the evaluation the effectiveness of the remedial action in reducing contamination to clean up levels
13) The list of ARARs and Tc Be Considered (TBC) information developed in the Characterization Report appears to be complete and well-discussed with the exception of several minor issues which are noted below in the Page-Specific Comments section The potential ARARs for the site have been taken directly fror the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) While there is nothing wrong with this approach it is recommended that consideration be given to each ARAR (and TBC information) with regards to any field activities which nay be planned and the information which may be required relative to potential ARARs Because of the iterative nature of the RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
14) The Characterization Report does not address contaminant fate and transport as required by the Order The Characterization Report containing the results of both the Phase IA and Phase IB investigations must evaluate contaminant fate and transport Even at this stage some analysis is warranted so that decisions can be made on the Phase IB work plan For example an explanation is required to resolve the presence of trace levels of volatile organic compounds that have shown up in the bedrock wells B-7-3 and B-2-3 What do these trace levels indicate about the fate and transport of contamination from the landfill
15) The following issues should also be noted
The Characterization Report is a public document and must be easy to interpret With the public in mind revise the Characterization Report to include more legible diagrams figures summary tables and comprehensive tables to facilitate data interpretation For example it is almost impossible to read ground water elevations on Figure 5-3
Background values must be included on summary tables of analytical data Also all values greater than the background value should be highlighted
Include the letters to EPA describing changes to the work plan as an appendix to the Draft RI Report
7
Include this corrrrent leTirer in an appendix to the Draf t R Reoort
ATTACHMENT II PAGE-SPECIFIC COMMENTS
31 Executive Summary
Pace ii ^2 The second sentience states that the information collected in the Phase 1A is considered to be sufficient to characterize the nature and extent of contamination at the site1
Percve this statement EPA is authorized to make this aerermination based on the contents of the Draft RI Report
Page ii laquo14 Second Bullet The geologic description of the 100shy520 feet layer is over-simplified Isolated thin water bearing fnoist to saturated) sandy layers were encountered within the dense dry till during drilling Also at B3-3 the interpretation of buried valley deposits containing pre-glacial s-reara sediments or glacial outwash is described to exist between -he overlying till and weathered bedrock (saprolites) below is oversimplified Provide a more detailed description of these significant variations in the text
Page iii f2 Groundwater Quality First Bullet States impact from the landfill on the shallow water table is limited to a small onsite area immediately adjacent to and downgradient of -he landfill EPA will make a determination defining onsite based on the contents of the Draft RI Report
Page iii 52 Groundwater Quality Second Bullet Laboratory detection limits are too high for comparison to MCLs for some VQCs SVOCs PCBs and metals Therefore it is inappropriate to s~ate that the bedrock groundwater samples did not contain any compounds at concentrations which exceed MCLs Qualify this statement to reflect compounds for which this statement is applicable
Also delete the last sentence in this section The risk assessment makes the determination of whether or not groundwater from the landfill adversely affects the quality of groundwater in bedrock
Page iii K3 Surface Water First Bullet States that the surface water samples do not exceed the Clean Water Act Water Quality Criteria for chronic exposures (CWA WQC) Do the surface water samples exceed CWA WQC for acute exposures
Page iv laquoJ2 Soils and Sediment Second Bullet Knowledge of the horizontal and vertical extent of the PCB contamination is necessary for the feasibility study Revise this sentence to reflect that the full extent of contamination has not yet been adequately delineated to complete the baseline risk assessment at either the drainage pond nor the area south of the landfill
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
Further definition rf the source of PC3 contamination tc the wetland ares south of the landfill is necessary
Leachate seeps were observed during the first round of groundwater sampling at the toe and midslope positions of the TSS pile nurber 3 Leachate was observed flowing into the drainage which eventually empties into the wetlands area south of the landfill Leachate from this sludge pile rust be evaluated for PCBs and metals
Upon removal of the sludge piles soil samples must be collected from the locations within the footprint of the former pile locations
Samples of surface vater and sediment must be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for u-se irtrtbe risk assessment purposes
Sampling is required to determine the horizontal and vertical (areal) extent of contamination within the drainage pond area and determine whether or not the drainage pond is a source of contamination
Additional saturated soil sampling is required in the area east of the drainage pond in order to determine the extent of the PCB contamination in the northeastern direction
Some additional groundwater information is required to delineate the extent of the ground water contamination detected at B-6 and B-5 While flow may be diverted back into the landfill because of the drainage structures this may not be the case Also additional information is required to evaluate groundwater south of the old landfill (where elevated soil gas concentrations were detected) between B-l and B-2 north of B-l and north of B-5 A well should be installed west of the drainage pond to determine if the pond itself is acting as a source of VOCs to B-5 Field screening efforts using methods such as screened augers microwells or hydropunch to collect samples for field GC volatile scans may be considered if the Settling Parties think they would be successful in penetrating the gravel layers In this way the number of monitoring wells could be minimized
Provide a discussion of the source of the contmination detected in the B-7-3 and B-5
7
8)
9)
10)
11)
-
12)
A sarple rust be collected from piezcreter B-9 and screened for VQCs to verify that nc contamination exists at this location
The Phase 1A RI hurar health risk assessrient evaluated exposures to ambient air using only current land use scenarios and did not evaluate noncarcinogenic effects Ambient air risks for potential future residents must also be evaluated
EPA requires that a full round of additional surface water and ground water samples be collected and analyzed for full TCLTAL parameters during winter or early spring months to evaluate seasonal variability in contaminant concentrations
EPA requires that grcundwater information (water balance) be compiled from the Phase 1A and Phase IB field activities which will allow the Settling Parties and EPA to understand the relationship of the site to local and regional groundwater This information will aid in design and remedy selection
More information is required regarding the determination of a horizontal flow component to groundwater flow Horizonatal flow information will assist in the determination of whether or not controls are necessary
The ground water flow direction contours presented are not accurate especially within the landfill because they do not take into account the potential effect of the underdrain system the lateral drains and the diversion ditch on flow within the landfill Since the results of the landfill cover evaluation suggest that the cover is not impermeable given the radial locations of the leachate outbreaks the potential for mounding within the landfill is very high
Additional information is required to further evaluate the hydraulic system in and around the landfill prior to remedial design EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Four piezometers (not necessarily in the buried lagoon) are required to evaluate the effectiveness of the source control containment remedial action One of the objectives of a source control remedial action is to reduce or prevent to the extent practicable infiltration of surface andor groundwater into the waste areas and leaching of contaminants from the waste areas into the groundwater below
and downgradiert cf the vaste The piezometers will provide infornaticr regarding the extent to which the water table has been lowered The intent of such monitoring is to evaluate the effectiveness of the containinment system and establish the impact of such measures on the water table Water level measurements will be one of several factors in the evaluation the effectiveness of the remedial action in reducing contamination to clean up levels
13) The list of ARARs and Tc Be Considered (TBC) information developed in the Characterization Report appears to be complete and well-discussed with the exception of several minor issues which are noted below in the Page-Specific Comments section The potential ARARs for the site have been taken directly fror the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) While there is nothing wrong with this approach it is recommended that consideration be given to each ARAR (and TBC information) with regards to any field activities which nay be planned and the information which may be required relative to potential ARARs Because of the iterative nature of the RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
14) The Characterization Report does not address contaminant fate and transport as required by the Order The Characterization Report containing the results of both the Phase IA and Phase IB investigations must evaluate contaminant fate and transport Even at this stage some analysis is warranted so that decisions can be made on the Phase IB work plan For example an explanation is required to resolve the presence of trace levels of volatile organic compounds that have shown up in the bedrock wells B-7-3 and B-2-3 What do these trace levels indicate about the fate and transport of contamination from the landfill
15) The following issues should also be noted
The Characterization Report is a public document and must be easy to interpret With the public in mind revise the Characterization Report to include more legible diagrams figures summary tables and comprehensive tables to facilitate data interpretation For example it is almost impossible to read ground water elevations on Figure 5-3
Background values must be included on summary tables of analytical data Also all values greater than the background value should be highlighted
Include the letters to EPA describing changes to the work plan as an appendix to the Draft RI Report
7
Include this corrrrent leTirer in an appendix to the Draf t R Reoort
ATTACHMENT II PAGE-SPECIFIC COMMENTS
31 Executive Summary
Pace ii ^2 The second sentience states that the information collected in the Phase 1A is considered to be sufficient to characterize the nature and extent of contamination at the site1
Percve this statement EPA is authorized to make this aerermination based on the contents of the Draft RI Report
Page ii laquo14 Second Bullet The geologic description of the 100shy520 feet layer is over-simplified Isolated thin water bearing fnoist to saturated) sandy layers were encountered within the dense dry till during drilling Also at B3-3 the interpretation of buried valley deposits containing pre-glacial s-reara sediments or glacial outwash is described to exist between -he overlying till and weathered bedrock (saprolites) below is oversimplified Provide a more detailed description of these significant variations in the text
Page iii f2 Groundwater Quality First Bullet States impact from the landfill on the shallow water table is limited to a small onsite area immediately adjacent to and downgradient of -he landfill EPA will make a determination defining onsite based on the contents of the Draft RI Report
Page iii 52 Groundwater Quality Second Bullet Laboratory detection limits are too high for comparison to MCLs for some VQCs SVOCs PCBs and metals Therefore it is inappropriate to s~ate that the bedrock groundwater samples did not contain any compounds at concentrations which exceed MCLs Qualify this statement to reflect compounds for which this statement is applicable
Also delete the last sentence in this section The risk assessment makes the determination of whether or not groundwater from the landfill adversely affects the quality of groundwater in bedrock
Page iii K3 Surface Water First Bullet States that the surface water samples do not exceed the Clean Water Act Water Quality Criteria for chronic exposures (CWA WQC) Do the surface water samples exceed CWA WQC for acute exposures
Page iv laquoJ2 Soils and Sediment Second Bullet Knowledge of the horizontal and vertical extent of the PCB contamination is necessary for the feasibility study Revise this sentence to reflect that the full extent of contamination has not yet been adequately delineated to complete the baseline risk assessment at either the drainage pond nor the area south of the landfill
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
7
8)
9)
10)
11)
-
12)
A sarple rust be collected from piezcreter B-9 and screened for VQCs to verify that nc contamination exists at this location
The Phase 1A RI hurar health risk assessrient evaluated exposures to ambient air using only current land use scenarios and did not evaluate noncarcinogenic effects Ambient air risks for potential future residents must also be evaluated
EPA requires that a full round of additional surface water and ground water samples be collected and analyzed for full TCLTAL parameters during winter or early spring months to evaluate seasonal variability in contaminant concentrations
EPA requires that grcundwater information (water balance) be compiled from the Phase 1A and Phase IB field activities which will allow the Settling Parties and EPA to understand the relationship of the site to local and regional groundwater This information will aid in design and remedy selection
More information is required regarding the determination of a horizontal flow component to groundwater flow Horizonatal flow information will assist in the determination of whether or not controls are necessary
The ground water flow direction contours presented are not accurate especially within the landfill because they do not take into account the potential effect of the underdrain system the lateral drains and the diversion ditch on flow within the landfill Since the results of the landfill cover evaluation suggest that the cover is not impermeable given the radial locations of the leachate outbreaks the potential for mounding within the landfill is very high
Additional information is required to further evaluate the hydraulic system in and around the landfill prior to remedial design EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Four piezometers (not necessarily in the buried lagoon) are required to evaluate the effectiveness of the source control containment remedial action One of the objectives of a source control remedial action is to reduce or prevent to the extent practicable infiltration of surface andor groundwater into the waste areas and leaching of contaminants from the waste areas into the groundwater below
and downgradiert cf the vaste The piezometers will provide infornaticr regarding the extent to which the water table has been lowered The intent of such monitoring is to evaluate the effectiveness of the containinment system and establish the impact of such measures on the water table Water level measurements will be one of several factors in the evaluation the effectiveness of the remedial action in reducing contamination to clean up levels
13) The list of ARARs and Tc Be Considered (TBC) information developed in the Characterization Report appears to be complete and well-discussed with the exception of several minor issues which are noted below in the Page-Specific Comments section The potential ARARs for the site have been taken directly fror the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) While there is nothing wrong with this approach it is recommended that consideration be given to each ARAR (and TBC information) with regards to any field activities which nay be planned and the information which may be required relative to potential ARARs Because of the iterative nature of the RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
14) The Characterization Report does not address contaminant fate and transport as required by the Order The Characterization Report containing the results of both the Phase IA and Phase IB investigations must evaluate contaminant fate and transport Even at this stage some analysis is warranted so that decisions can be made on the Phase IB work plan For example an explanation is required to resolve the presence of trace levels of volatile organic compounds that have shown up in the bedrock wells B-7-3 and B-2-3 What do these trace levels indicate about the fate and transport of contamination from the landfill
15) The following issues should also be noted
The Characterization Report is a public document and must be easy to interpret With the public in mind revise the Characterization Report to include more legible diagrams figures summary tables and comprehensive tables to facilitate data interpretation For example it is almost impossible to read ground water elevations on Figure 5-3
Background values must be included on summary tables of analytical data Also all values greater than the background value should be highlighted
Include the letters to EPA describing changes to the work plan as an appendix to the Draft RI Report
7
Include this corrrrent leTirer in an appendix to the Draf t R Reoort
ATTACHMENT II PAGE-SPECIFIC COMMENTS
31 Executive Summary
Pace ii ^2 The second sentience states that the information collected in the Phase 1A is considered to be sufficient to characterize the nature and extent of contamination at the site1
Percve this statement EPA is authorized to make this aerermination based on the contents of the Draft RI Report
Page ii laquo14 Second Bullet The geologic description of the 100shy520 feet layer is over-simplified Isolated thin water bearing fnoist to saturated) sandy layers were encountered within the dense dry till during drilling Also at B3-3 the interpretation of buried valley deposits containing pre-glacial s-reara sediments or glacial outwash is described to exist between -he overlying till and weathered bedrock (saprolites) below is oversimplified Provide a more detailed description of these significant variations in the text
Page iii f2 Groundwater Quality First Bullet States impact from the landfill on the shallow water table is limited to a small onsite area immediately adjacent to and downgradient of -he landfill EPA will make a determination defining onsite based on the contents of the Draft RI Report
Page iii 52 Groundwater Quality Second Bullet Laboratory detection limits are too high for comparison to MCLs for some VQCs SVOCs PCBs and metals Therefore it is inappropriate to s~ate that the bedrock groundwater samples did not contain any compounds at concentrations which exceed MCLs Qualify this statement to reflect compounds for which this statement is applicable
Also delete the last sentence in this section The risk assessment makes the determination of whether or not groundwater from the landfill adversely affects the quality of groundwater in bedrock
Page iii K3 Surface Water First Bullet States that the surface water samples do not exceed the Clean Water Act Water Quality Criteria for chronic exposures (CWA WQC) Do the surface water samples exceed CWA WQC for acute exposures
Page iv laquoJ2 Soils and Sediment Second Bullet Knowledge of the horizontal and vertical extent of the PCB contamination is necessary for the feasibility study Revise this sentence to reflect that the full extent of contamination has not yet been adequately delineated to complete the baseline risk assessment at either the drainage pond nor the area south of the landfill
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
and downgradiert cf the vaste The piezometers will provide infornaticr regarding the extent to which the water table has been lowered The intent of such monitoring is to evaluate the effectiveness of the containinment system and establish the impact of such measures on the water table Water level measurements will be one of several factors in the evaluation the effectiveness of the remedial action in reducing contamination to clean up levels
13) The list of ARARs and Tc Be Considered (TBC) information developed in the Characterization Report appears to be complete and well-discussed with the exception of several minor issues which are noted below in the Page-Specific Comments section The potential ARARs for the site have been taken directly fror the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) While there is nothing wrong with this approach it is recommended that consideration be given to each ARAR (and TBC information) with regards to any field activities which nay be planned and the information which may be required relative to potential ARARs Because of the iterative nature of the RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
14) The Characterization Report does not address contaminant fate and transport as required by the Order The Characterization Report containing the results of both the Phase IA and Phase IB investigations must evaluate contaminant fate and transport Even at this stage some analysis is warranted so that decisions can be made on the Phase IB work plan For example an explanation is required to resolve the presence of trace levels of volatile organic compounds that have shown up in the bedrock wells B-7-3 and B-2-3 What do these trace levels indicate about the fate and transport of contamination from the landfill
15) The following issues should also be noted
The Characterization Report is a public document and must be easy to interpret With the public in mind revise the Characterization Report to include more legible diagrams figures summary tables and comprehensive tables to facilitate data interpretation For example it is almost impossible to read ground water elevations on Figure 5-3
Background values must be included on summary tables of analytical data Also all values greater than the background value should be highlighted
Include the letters to EPA describing changes to the work plan as an appendix to the Draft RI Report
7
Include this corrrrent leTirer in an appendix to the Draf t R Reoort
ATTACHMENT II PAGE-SPECIFIC COMMENTS
31 Executive Summary
Pace ii ^2 The second sentience states that the information collected in the Phase 1A is considered to be sufficient to characterize the nature and extent of contamination at the site1
Percve this statement EPA is authorized to make this aerermination based on the contents of the Draft RI Report
Page ii laquo14 Second Bullet The geologic description of the 100shy520 feet layer is over-simplified Isolated thin water bearing fnoist to saturated) sandy layers were encountered within the dense dry till during drilling Also at B3-3 the interpretation of buried valley deposits containing pre-glacial s-reara sediments or glacial outwash is described to exist between -he overlying till and weathered bedrock (saprolites) below is oversimplified Provide a more detailed description of these significant variations in the text
Page iii f2 Groundwater Quality First Bullet States impact from the landfill on the shallow water table is limited to a small onsite area immediately adjacent to and downgradient of -he landfill EPA will make a determination defining onsite based on the contents of the Draft RI Report
Page iii 52 Groundwater Quality Second Bullet Laboratory detection limits are too high for comparison to MCLs for some VQCs SVOCs PCBs and metals Therefore it is inappropriate to s~ate that the bedrock groundwater samples did not contain any compounds at concentrations which exceed MCLs Qualify this statement to reflect compounds for which this statement is applicable
Also delete the last sentence in this section The risk assessment makes the determination of whether or not groundwater from the landfill adversely affects the quality of groundwater in bedrock
Page iii K3 Surface Water First Bullet States that the surface water samples do not exceed the Clean Water Act Water Quality Criteria for chronic exposures (CWA WQC) Do the surface water samples exceed CWA WQC for acute exposures
Page iv laquoJ2 Soils and Sediment Second Bullet Knowledge of the horizontal and vertical extent of the PCB contamination is necessary for the feasibility study Revise this sentence to reflect that the full extent of contamination has not yet been adequately delineated to complete the baseline risk assessment at either the drainage pond nor the area south of the landfill
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
7
Include this corrrrent leTirer in an appendix to the Draf t R Reoort
ATTACHMENT II PAGE-SPECIFIC COMMENTS
31 Executive Summary
Pace ii ^2 The second sentience states that the information collected in the Phase 1A is considered to be sufficient to characterize the nature and extent of contamination at the site1
Percve this statement EPA is authorized to make this aerermination based on the contents of the Draft RI Report
Page ii laquo14 Second Bullet The geologic description of the 100shy520 feet layer is over-simplified Isolated thin water bearing fnoist to saturated) sandy layers were encountered within the dense dry till during drilling Also at B3-3 the interpretation of buried valley deposits containing pre-glacial s-reara sediments or glacial outwash is described to exist between -he overlying till and weathered bedrock (saprolites) below is oversimplified Provide a more detailed description of these significant variations in the text
Page iii f2 Groundwater Quality First Bullet States impact from the landfill on the shallow water table is limited to a small onsite area immediately adjacent to and downgradient of -he landfill EPA will make a determination defining onsite based on the contents of the Draft RI Report
Page iii 52 Groundwater Quality Second Bullet Laboratory detection limits are too high for comparison to MCLs for some VQCs SVOCs PCBs and metals Therefore it is inappropriate to s~ate that the bedrock groundwater samples did not contain any compounds at concentrations which exceed MCLs Qualify this statement to reflect compounds for which this statement is applicable
Also delete the last sentence in this section The risk assessment makes the determination of whether or not groundwater from the landfill adversely affects the quality of groundwater in bedrock
Page iii K3 Surface Water First Bullet States that the surface water samples do not exceed the Clean Water Act Water Quality Criteria for chronic exposures (CWA WQC) Do the surface water samples exceed CWA WQC for acute exposures
Page iv laquoJ2 Soils and Sediment Second Bullet Knowledge of the horizontal and vertical extent of the PCB contamination is necessary for the feasibility study Revise this sentence to reflect that the full extent of contamination has not yet been adequately delineated to complete the baseline risk assessment at either the drainage pond nor the area south of the landfill
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
ATTACHMENT II PAGE-SPECIFIC COMMENTS
31 Executive Summary
Pace ii ^2 The second sentience states that the information collected in the Phase 1A is considered to be sufficient to characterize the nature and extent of contamination at the site1
Percve this statement EPA is authorized to make this aerermination based on the contents of the Draft RI Report
Page ii laquo14 Second Bullet The geologic description of the 100shy520 feet layer is over-simplified Isolated thin water bearing fnoist to saturated) sandy layers were encountered within the dense dry till during drilling Also at B3-3 the interpretation of buried valley deposits containing pre-glacial s-reara sediments or glacial outwash is described to exist between -he overlying till and weathered bedrock (saprolites) below is oversimplified Provide a more detailed description of these significant variations in the text
Page iii f2 Groundwater Quality First Bullet States impact from the landfill on the shallow water table is limited to a small onsite area immediately adjacent to and downgradient of -he landfill EPA will make a determination defining onsite based on the contents of the Draft RI Report
Page iii 52 Groundwater Quality Second Bullet Laboratory detection limits are too high for comparison to MCLs for some VQCs SVOCs PCBs and metals Therefore it is inappropriate to s~ate that the bedrock groundwater samples did not contain any compounds at concentrations which exceed MCLs Qualify this statement to reflect compounds for which this statement is applicable
Also delete the last sentence in this section The risk assessment makes the determination of whether or not groundwater from the landfill adversely affects the quality of groundwater in bedrock
Page iii K3 Surface Water First Bullet States that the surface water samples do not exceed the Clean Water Act Water Quality Criteria for chronic exposures (CWA WQC) Do the surface water samples exceed CWA WQC for acute exposures
Page iv laquoJ2 Soils and Sediment Second Bullet Knowledge of the horizontal and vertical extent of the PCB contamination is necessary for the feasibility study Revise this sentence to reflect that the full extent of contamination has not yet been adequately delineated to complete the baseline risk assessment at either the drainage pond nor the area south of the landfill
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
Page iv Leach^te First Bullet States Leachate at the Sire has beer adequately characterized EPA makes this deter-irat ion cased on the Draft RI Report Remove this statement
Page v Buried Lagocn Third Bullet What is the basis for assuming that the original elevation of the lagoon is the same elevation as the buried lagoons contamination (plus or minus two feet) (ieliquid waste ray have saturated the soils below the buried lagoon) Furthermore there may be groundwater mounding within the landfill (as evidenced by several leachate outbreaks) that would not be measurable given the available observation well network Groundwater data is needed to evaluate the mounding within the landfill not necessarily within the buried lagoon area itself
Page vi Ecological Assessment Fourth Bullet The potential risk to ecological receptors is currently being evaluated by the EPA but the assessment has not yet been completed Remove statements regarding potential ecological risk
Page vi Additional Data Requirements First Bullet As discussed previously in the general comments section (5) additional data on the extent of contamination is required The extent of the PCB contamination in the area northeast of the drainage pond and south of the landfill has not yet been defined Level 4 quality data from the drainage pond are required for the risk assessment
Page vi Additional Data Requirements Third Bullet There are gaps in the shallow aquifer monitoring well network More information is required regarding the area south and east of the old landfill upgradient and downgradient of the drainage pond and north of the drainage pond to evaluate the groundwater at these locations A groundwater sample must be collected at the B-9 piezometer to obtain rore information regarding the area north of the drainage pond
Page vii Additional Data Requirements First Bullet The first sentence in this bullet needs to be revised or deleted to indicate that there is presently only one down gradient bedrock bullbullell (B2-3) Also trace levels of volatiles have been detected in ground water in the bedrock
The summary table at the end of this chapter must be revised to include EPA Phase IB requirements outlined in this comment letter
32 Background
Page 2-2 [4 sect22 The text regarding the TSS area must be revised to reflect existing conditions As of June 1993 the four foot U-shaped berms required by state regulations were on the order of two feet high Also include in the text that there were breaches in the native soil berms tarps have blown
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
10
cff and rain water infilrrares_the TSS piles and escapes the rerred area as leachate trrcugh the breaches
Page 2-5 ^2 sect23 Include en the map the monitoring wells installed by the Town of Bennington as part of their state cerrit
Page 2-6 52 sect23 The sratement that metals concentrations in dcrestic wells do not reflect impact from the landfill must be backed with data and comparison to site-specific background data
Page 2-9 laquoJ2 amp ^3 sect241 and sect242 Please provide the schematic rrap showing the approximate locations of the diversion ditches and the underdrains Figure 1 must be adapted to show the current understanding of ~he location of the buried lagoon depict the overall layout of the Site and the wetland boundaries vetlands have only been designated in one area southeast of the landfill while the closer wetlands south and west of the landfill have not been designated Approximate wetland boundaries can only be assumed from those locations labelled as sedirents and from cross-referencing with Appendix D Figure 4-2 Addirionally surface water drainage patterns are difficult to ascertain and therefore it is difficult to assess potential conramination pathways
Also clarify the source of the drainage in the diversion ditch Water from this ditch is supposed to drain from the west end of the landfill into the wetland at the south end of the landfill Is this ditch still functionally operational or not
33 Adherence To The Project Operations Plan
Page 3-2 51 sect322 The second sentence states that a thin saturated surficial unit is underlain by a dense non-water bearing material hundreds of feet in thickness Correct this statement is as it is too general to describe actual subsurface conditions There are also thin sandy zones that were moist to saturated within the massive dry dense till At B-5-3 a 22 foot thick zone of saturated sand with varying amounts of gravel vas encountered beneath approximately 130 feet of low permeable material Expand the text to include these observations Also include letters to EPA describing the changes to the scope and approved work plan in an appendix of the Draft RI Report
Page 3-3 fl sect323 The paragraph states that the 6-inch casing could not be advanced beyond depths of 150 feet by the dual air-rotary method (Barber rig) This statement is to general Correct the text to include specific details such as At B-3-3 the Barber rig encountered refusal at approximately 150 feet in dense dry overburden material However the Barber rig did advance the 6-inch casing to 232 feet at B-l-3 and 220 feet at Bshy5-3 without encountering refusal
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
11
40 Summary of Phase 1A Field^Activities
Page 4-2 lt[4 sect422 Include a summary of findings in tris sec-ion to be consistent with the rest of the text Also correct tre text to indicate chat the seismic survey was not effective in defining the depth to bedrock across the site
Page 4-4 sect4221 Samples of surface water and sediment need to be collected from the area within drainage pond for full TALTCL (Level 4 quality data) for risk assessment purposes
Page 4-4 sect4321 The purpose of this part of the Characterization Report is to delineate more precisely the downstream extent of PCBs detected in surface water and sediments However surface water was not sampled due to its absence at the time of sampling Surface water when seasonally present in this area must be collected to evaluate the mechanism for transport of PCBs
Page 4-6 sect433 Include a table which summarizes the depths at which saturated soils were encountered and at what depths PCBs bullere detected This is also not detailed in Section 6122 as referenced
Page 4-6 sect4332 and Figure 4-2 Revise the map (or include a second map) to clearly differentiate the subsurface soil samples from the surface soil samples (both mobile and CLP laboratory samples)
Page 4-8 54 sect4343 and Page 4-12 sect443 The text states that the PCBs detected do not represent a significant ecological impact The ecological risk assessment is currently being performed by EPA but results are not yet available Conclusions regarding the impact of contamination are not appropriate at this time Edit the text accordingly
Page 4-9 fl sect441 There appears to be only two surface water samples for the entire drainage area east of the drainage pond Explain in the test why this is sufficient to accurately characterize Ponds A B and C and the linking surface waters
Page 4-9 53 sect4411 Any contamination detected in sediment samples collected in the ditch may or may not be associated with or representative of the buried lagoon As a point of clarification samples from this ditch would have been reguired even if there had not been a buried lagoon
Page 4-12 53 sect443 Remove the last sentence in this paragraph EPA will make the determination whether the concentration of compounds detected represent a significant potential ecological impact as part of the Final RI determination
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
12
Psge 4-13 3 sect4411 The text states that VOC concentrations v-ere less than these found in Burlington Vermont during 1933 S EPA Urban Air Toxics Sampling Program Include data to allc- this office to verify this statement
Page 4-19 ^6 sect472 Indicates that a human health risk assessment was conducted to evaluate transfer station workers exposure due to inhalation of airborne PC3 Arochlor 1242 measured during the Phase 1A Air Quality Assessment The results of the risk assessment show PCS on airborne particulate dees not pose unacceptable increase in exposure risk to the workers at the transfer station In addition to evaluating the risk to workers at the transfer station include a discussion on the air quality exposure risk to the public in this section
Page 4-23 laquo2 sect4833 The closure plan approved by the State of Vermont required a minimum of two feet of cover material with permeability of 5 x 10-6 cmsec Add this statement to the text
As a note It is EPAs assessment that the current cap conditions do not have the specifications to act as an adequate infiltration barrier based on an estimated cap thickness between 12-18 inches (thinner than required by state permit) and the permeability ranges 213 X 10-3 to 950 X 10-4 cmsec (more permeable than required by state permit)
Page 4-24 sect492 Fifth Bullet This statement is premature based on the available data The report states that the referenced macrobenthic invertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of these data limits the suitability of these reference stations Reference stations must allow comparisons between the onsite samples and reference samples to be made The refererence station comparisons limit the wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
Page 4-27 laquo[1 sect41011 This paragraph should be revised to state that at most boring locations the initial borehole was started with hollow stem augers and continued until refusal was encountered The Barber rig was then utilized to complete the boring until bedrock or refusal in overburden material As previously stated the exception was at soil borings B-l-2 B-3shy1 B-4-1 B-6-1 and B-6-3 where the dual air-rotary Barber rig was used first in order utilize the rig to speed up the drilling program andor due to the type of overburden material This change in the drilling procedure was approved by EPA
Page 4-27 [2 sect41011 Revise this paragraph to state that on at least five occasions the discharge hose broke apart allowing drill cuttings to be discharged onto the ground surface Also
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
13
cr several occasions the drurs over-flowed allowing cuttings to ce discharged to the ground surface Water was used periodically ro aid in cutting through the dense overburden material and to clean-out the inside of the casing and discharge hose
Page 4-27 ^2 sect41011 Revise the drilling discussion It is ever simplified and ncre detail is needed regarding the procedure for drilling through boulders Initially when refusal was encountered the Barber rig moved off location the auger rig -oved on location and started coring to confirm bedrock or through the boulders After several episodes of coring through boulders and disproving the depth to bedrock interpreted from the seismic data the Barber rig then used the downhole air hammer to drill up to five feet into rock to confirm bedrock or boulders This change in drilling procedures was approved by EPA and saved a considerable amount of tine moving the different rigs from one location to another
Page 4-27 ^4 sect41011 Revise this discussion to include more detailed information clarifying at which borings the method described was utilized The situation as stated only occurred at soil boring 3-3-3
Page 4-28 ^2 sect41011 Revise the text to provide more detail regarding the inability of the rig to advance the 4-inch casing The situation as described is over simplified and not accurate in reference to the inability of the rig to advance the 4-inch casing The casing advancer was used at only two locations soil borings B-2-3 and B-3-3 At B-2-3 the use of the 4-inch casing advancer was terminated due to exceeding the capabilities of the wire line At B-3-3 an obstruction was encountered at approximately 267 feet
Page 4-29 f3 sect41011 Revise this paragraph to state that potable water was added to the air stream to aid in flushing drill cuttings from the borehole
Page 4-30 53 sect41012 Revise this paragraph to state that monitoring well B-8-1 was screened slightly below the ground water surface in order to construct an adequate surface seal
Page 4-30 laquo[4 sect4102 Clarify the following in the text 1) That there were thin sandy zones that were moist to saturated within the massive dry dense till at soil borings B-l-3 B-2-3 B-3-3 and B-5-3 2) At B-5-3 a 22 foot zone of saturated sand with varying amounts of gravel was encountered beneath approximately 130 feet of low permeable material 3) No clearly interconnected bullwater-bearing unit 7 was identified
Page 4-32 laquo[3 sect41011 Section 324 indicated that modifications were made to Section 5421 of the FSP to ensure adequate working space to allow for proper grouting of the well riser pipe Unfortunately at B-2-3 approximately 275 feet of
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
14
rhe temporary4-irch steel casing remains in the bottom cf the borehole Provide further discussion of the construction issues related to this veil and the uncertainty related to the integrity of che grout seal between the sides of the borehole and the remaining 4-inch casing
Page 4-34 52 sect 41022 Clarify in the text that the bailers used were constructed of both teflon and stainless steel
Page 4-39 2 sect 41042 Revise this paragraph to state that the surveyed reference point was the top of the PVC riser pipe on all wells installed during the Phase 1A investigation Piezometers installed during the Phase 1A referenced the top of the metal riser pipe (except B-9 and 3-10 which referenced the top of PVC) Previously installed wells and piezometers referenced the top of PVC with the exception of Well - SOL (See table in Appendix J)
Page 4-44 laquoJ2 sect41053 Revise Table 4-5 to clearly identify bullveils for and which the falling head test results are not valid ie the Table 4-5 wells at which the static water level was within the screened interval
Page 4-44 [5 sect41053 Revise this paragraph to include B-3-1 as one of the wells screened in the very fine sand and silt unit west and south of the landfill
Page 4-45 f2 sect41053 A harmonic oscillatory response is evident in the data for B-2-3 The analytical method described in the following reference may be applicable as it is appropriate for confined aquifers and wells with long saturated columns Since the determination of an aquifer storativity was not based upon a complete data set the use of a literature derived storativity may be appropriate for example Van der Kamp Garth 1976Determining Aquifer Transmissivity by Means of Well Response Tests The Underdamped Case Water Resources Research Volume 12 No 1 pages 71-77
Page 4-48 ^2 sect41062 Revise this paragraph to state that the lowest obtainable flow rate at B-2-3 was 200 mlmin
Page 4-50 sect4112 At the time that the LFI was being conducted the aerial photographs available did not provide conclusive evidence of the location of the buried lagoon Clarify if additional photographs were obtained or if knowledgeable personnel confirmed or subsequently identified the location of the buried lagoon on the aerial photographs
Describe the methodology and degree of accuracy of the photogrammetric analysis Typically the vertical accuracy is plus or minus 2 feet and the horizontal accuracy is plus or minus 1 foot If the surveyor produced a report include it in an Appendix
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
15
Page 4-50 sect4-112 EPA Ccnnentj Given the elevations (940 to 950 feet) and locations of the leachate seeps it is still possible uhat due to mounding the water table may be near or at the suspected elevation of the buried lagoon (946-949 feet) Furthermore contamination from the buried lagoon may extend belcw the depth of the original buried lagoon and acr as a continuing source of contamination
Based on the historical data provided in the report the Town of Bennington installed the diversion ditch and the underground drainage system to divert surface water and shallow ground water from wet conditions in some areas of the western portion of the landfill The buried lagoon was buried under landfill material after attempts to dewater the buried lagoon failed These observations lead to the conclusion that waste was historically within the water table
Correct Figure 4-7 Correct NW to NW on the cross section with the appropriate designations
Page 4-51 52 sect4113 Revise the use of the word historical with respect to the water level data collected over 1 year (1993) It is slightly misleading and should be deleted from this context If water level data from the wells monitored by the town over a period of years are available data it would be useful to evaluate these data to get a sense of the historical water level fluctuations
Page 4-52 ^2 sect4113 Correct the size of the buried lagoon depicted in Figure 4-6 and that described in the text The size of the buried lagoon depicted in Figure 4-6 is not the same as that described in the text The volume of the buried lagoon would be more on the order of 700 cubic yards of material based on the area shown on Figure 4-6 and an average thickness of 3 feet
Page 4-53 Items 1 and 2 sect4113 There are data gaps in the downgradient well network that need to be filled before a determination can be made regarding migration of contamination from the site Better definition of the shallow flow regime is needed In addition the effects of landfill mounding and the drainage system must be evaluated What is the source of the contamination detected in B-7-3 What is the source of the contamination detected in the B-5 well cluster These data gaps need to be addressed in the Phase IB before the proposed conclusions listed in items 1 and 2 can be accepted
Page 4-53 [4 sect4113 The depth of the buried lagoon beneath the landfill debris (10-30 feet) stated in this paragraph is inconsistent with previous statements in the text Page 2-1 states approximately 30 feet Page 4-51 states 10-20 feet and Figure 4-6 illustrates 5-20 feet Correct these inconsistencies
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
16
Ccrrecr ~he text to include -hat OSHA regulations require a 115 slope ra~io (rise over run) rather than the assumption made of 11 The OSHA requirement estimates that approximately 6000 cubic yards of material would have to be removed to expose the buried lagoon
Page 4-54 laquo[1 sect4113 The buried lagoon deposits have not been sarpled or characterized--therefore it is not possible to eliminate it as a potential contaminant source to ground water at 3-5 or east of the landfill Further since the hydraulics and flow patterns in and around the landfill have not been well defined it is not clear that the existing monitoring well network is adequate to define a plume Propose additional investigations for the Phase IB to provide data to support to these conclusions
Page 4-54 f2 sect4113 The text states that the buried lagoon is located above rhe water table The site history (which indicates difficulty in dewatering the buried lagoon sludge) suggests that the waste was deposited at or near the water table In addition infiltration of liquid wasre from the buried lagoon to the subsurface may result in the source being below the elevation of the actual buried lagoon The analysis presented does not account for the elevation of the observed leachate seeps which suggest mounding or the effect of the underdrain system Generally landfills tend to develop ground water mounds
The data currently is insufficient to evaluate whether the water table is actually above or below waste or the buried lagoon EPA requires that information be gathered to evaluate groundwater flow within the landfill This information is necessary to predict groundwater levels (mounding) leachate gradients the effects of the underdrain on the groundwater flow system and migration of contamination away from the Site In addition this information is needed to design and locate leachate collection systems
Page 4-54 f4 sect4113 Although remediation efforts could involve the issues outlined in this paragraph the proposed investigation consisting of soil borings and piezometers would not LDR and treatability issues should not arise as a result of the investigation of the buried lagoon Furthermore the statement that hundreds of thousands of cubic yards of waste would be generated is incorrect Correct the text to state that five to ten thousand cubic yards might have to be moved to ensure slope stability
Also the last sentence in this paragraph is incomplete Please complete the last sentence to state the now buried lagoon
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
17
35 Physical Characteristics
Page 5-1 [4 sect5111 Label the physiographic features en Figure 2-1 more clearly
Page 5-7 ^3 sect5121 Discuss the similarities in bedrock lithology at OC-6 and 3-4-3 Also discuss the presence of three faults at OC-6 their orientation the similarity to the orientation of fractures at OC-1 and the potential of a fault between B-7-3 B-6-3 and the landfill
Page 5-10 lt[4 sect 5122 Include in the text further description regarding the saprolite detected at this site Further description is needed regarding the rationale for identifying this rock as a saprolite Discuss any similarities between the veathered bedrock observed at B-6-3 and the massive saprolite deposits in B-2-3 Is there any correlation between the seismic interpreted depth of bedrock and the top of the saprolite
Page 5-15 ^2 sect5221 State in the text what depth below ground surface the sand and gravel layer was detected at 8-5-3 Address the potential for aquifer interconnection and possible need for a well in that zone since some local residential water wells may be completed in such deposits
Page 5-16 f3 sect 5222 Revise this paragraph to reference which wells are upgradient and downgradient of the landfill Wells B-7-1 B-8-1 and B-12 are upgradient Wells B-3-1 and B-6-1 are side gradient Wells B-l-1 B-l-2 B-2-1 B-2-2 B-5-1 and B-5-2 are downgradient
Page 5-17 [3 sect 5222 Revise this paragraph to include north as a high point from which the surface topography slopes down towards Hewitt Brook in the vicinity of the site
Page 5-18 fl sect5222 Discuss the difference in direction of apparent dip of bedding planes between OC-1 and OC-6 and whether it has any significance in controlling the direction of ground water flow in the bedrock aquifer
Plate II Geologic Cross Sections - The cross sections must show the depths to which split spoon samples were collected and where the interpretations rely on cuttings from the mud rotary drilling process Formation description was not generally possible in the mud rotary cuttings
bull 36 Analysis of Sampling Results
Page 6-2 53 sect60 The text states that the positive pesticide results except for DDT DDE and ODD should be viewed as false positive False positive results were flagged R (rejected) as unusable The criteria for data rejection and rationale for this conclusion were further defined in Appendix F to the report The
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
18
criterion for rejection vas a percent difference between the reported results frcr the primary and confirmatory analyses greater than 90 percent Such rejection of confirmed pesticide concentrations is inappropriate because it presumes that the lower concentration is the result of interference Only the difference between the higher and lower concentrations can be attributed to interference Since rejecting positive results vill result in an underestimation of risk the lower concentration from the primary and confirmatory analysis must be reported as a confirmed positive
Page 5-2 J[4 sect60 Include a statement that the QAQC requires a 90 completeness of all laboratory analysis results
Page 6-3 53 sect611 Although PCBs were not detected in SD-22 it is net mentioned if PCBs were absent from SWATSED-01 The absence of PCBs in these locations does not preclude the possibility of PCBs in Pond C Samples are required in areas of high sedimentation directly downgradient from the stream entry into the pond and in low energy organic substrates
Page 6-4 51 sect6121 Indicate in the third sentence the concentrations at which PCBs were detected (2 to 9 mgkg) at SS-50NNW25W and SS-75NNW
Page 6-4 fl2 sect6121 Revise this statement Sample number SS-25NNE should not be used as a location to define the extent of PCB surface contamination The Mobile Laboratory analysis results for SS-25NNE detected 0058 ppm of Aroclor-1242
Aroclor-1016 was detected by the CLP laboratory at estimated concentrations in samples SS-75NNW 35W and SS-100NNW 25W There are no CLP analytical results for sample number SS-75NNW 25E should this be SS-75NNW 15E Please clarify or correct
Page 6-5 51 sect6122 There were no samples submitted for CLP confirmatory analysis There were also no samples collected east of sample SAT-100NNW where Aroclor-1242 was detected at 0090 rigkg Therefore the extent of PCB contamination in this direction has not been defined Define PCB contamination in this direction
Page 6-6 f2 sect613 Further sampling is required to delineate both the horizontal and vertical extent of PCB contamination in the area south of the landfill Analyses of all samples found detectable concentrations of PCBs Samples should be collected at the 950 940 and 930 foot contours
The ecological risk assessment has not yet been completed by EPA Remove the statement regarding the relative risk of the PCBs in the wetland
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
19
Pace 5-6 53 sect 52 1 Describe in more detail why the surface -a~er background Iccaticr was thought not to be receiving discharge from the landfill drainage area No pond lake or szrearr is shown on Plate I in this area Correct the map to show ~he surface water body
Page 6-7 56 sect622 Clarify that the area being evaluated by SWAT-11 and SWAT-12 is the area southeast of the landfill east cf the access road
Page 6-8 51 Section 623 This is the first indication of the orthern Gravel Pit as a potential receptor of site-derived contamination Delineate the Northern Gravel Pit Drainage Pond the Buried Lagoon or Hewitt Brook on Plate I These designations would have been helpful in identifying areas of concern Provide a discussion of the rationale used to determine whether or not sedirent contamination is an issue Explain why analyses for this area focused solely on TCL volatiles without TCL pesticidesPCBs and senivolatiles or TAL inorganics
Page 6-9 55 Section 625 The presence of elevated volatile crganics and inorganics in SWAT-07 further reinforces the need to verify conditions in Pond C Lead detection at SWAT-06 is an order of magnitude above the AWQC Although the duplicate sample (SWAT-006) did not indicate the presence of lead the high detection in SWAT-06 and the elevated level at SWAT-07 pose unanswered questions as to the source of the elevated lead levels
Page 6-10 lt[5 The Report states that lead detected at SWAT-06 and SWAT-07 (395 and 16 ugL respectively) above AWQC (32 ugL) are not of concern since a duplicate of SWAT-06 did not detect lead and lead was detected above AWQC at background sample BGSWAT-02 (58 ugL) However the lead AWQC is water hardness dependent Adjusting the lead chronic AWQC at BGSWAT-02 results in a detected background concentration below AWQC Please note
Page 6-12 53 sect632 State if estimated levels of semivolatiles were below CRQLs and give the ranges
Page 6-12 54 sect632 Does the background concentration of mercury at SED-16 exceed the NOAA ER-L value
Page 6-13 51 sect632 Provide the levels at which magnesium riercury and silver were detected and by what factor these concentrations exceed background
Page 6-13 52 sect633 Explain if SED-11 and SED-12 were selected as potentially clean locations to provide CLP quality data to delineate boundaries Were any samples collected in the hottest location
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
20
Page 6-13 f3 ltsect633 State the^levels at which metals were detected Does the background concentration of mercury and lead at SED-11 exceed the NCAA ER-L values
Page 6-14 sect634 Provide levels at which analytes were detected
Page 6-14 sect634 Does the above background concentration of arsenic at SED-0304 exceeded the NOAA ER-L value
It was stated in Section 4414 that SED-02 had the highest PC3 detection in the LFI Include a discussion of the ramifications as to why no PCB detection are reported for this location
Page 6-15 fl2 sect634 See the comment for Page 6-2 53
Page 6-15 4 Section 635 State in the text if the above background concentrations of arsenic at SED-07 manganese at SED-070809 and zinc at SED-06 exceeded respective NOAA ER-L values
Page 6-17 51 sect636 The last sentence makes claims about impacts to the environment which are not substantiated since the risk assessment has not been completed Remove these statements from the text
Page 6-17 f4 sect641 Indicate the levels at which the analytes were detected
Page 6-19 sect642 The extent of migration of contaminants from these seeps is unclear Do seep waters remain fairly contained for a short distance in surface soils Do seep waters reach standing surface water
Page 6-22 51 sect651 Revise text to include the background soil samples collected at locations both east and west of the landfill as indicated on Plate I
Page 6-26 52 sect661 The field or laboratory blank data must be used in accordance with EPA Region I data validation guidelines to determine the usability of data for the common laboratory contaminants Also the text must be specific about the wells and concentrations at which analytes were detected
37 Applicable or Relevant and Appropriate Requirements (ARARS)
Page 7-1 52 sect71 The list of ARARs and To Be Considered (TBC) information developed by McLarenHart appears to be complete and well-discussed with the exception of several minor issues The potential ARARs for the site have been taken directly from the guidance document Conducting Remedial InvestigationFeasibility Studies Under CERCLA (US EPA 1991) There is nothing wrong with this approach but it is recommended that consideration be given to each ARAR (and TBC information) with regards to any
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
21
field activities whici ray be planned and the information which ray be required relat_ve to potential ARARs Because of the iterative nature of t~e RIFS process ARAR identification continues throughout the RIFS as a better understanding is gained of site conditions site contaminants and remedial action alternatives
Table 7-1 Page 2 of 3 The Federal location-specific ARAR regarding historic projects owned or controlled by a federal agency has been duplicated in Table 1
Table 7-3 Three potential ARARs have been omitted under the Page 5 of 18 action involving consolidation of wastes The ARARs which have been omitted are
Develop fugitive and odor emission control plan for the action if existing site plan is inadequate Citation Clean Air Act (CAA) Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each pollutant expected Citation 40 CFR 52
These potential requirements should be inserted preceding the first ARAR listed on page 12
Table 7-3 Page 8 of 18 The citation for the requirement of Establish specific procedures for the control of toxic and hazardous pollutant spills under the Best Management Practices (BMP) program should be 40 CFR 125104
Table 7-3 Page 12 of 13 The hydrogen sulfide emissions should not create an ambient concentration greater than or equal to 010 parts per million (ppm) not 001 ppm as stated
Table 7-3 Page 13 of 18 The following potential ARARs have been omitted from Table 3 for the Land Treatment Action
Special requirements for ignitable or reactive wastes Citation 40 CFR 264281
Special requirements for incompatible wastes Citation 40 CFR 264282
Special requirements for RCRA hazardous wastes Citation 40 CFR 264283
Design system to operate odor free Citation CAA Section 101 and 40 CFR 52
File an Air Pollution Emission Notice (APEN) with the state to include an estimation of emission rates for each
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
22
pollutant expected Citation 40 CFR 52 Include with the filed APEN tne following
Modeled impact analysis of source emissions
A Best Available Control Technology (BACT) review for the source operation
Predict total emissions of volatile organic compounds (VOCs) to demonstrate emissions do not exceed 450 pounds per hour (Ibhr) 3000 Ibday 10 gallons per day (galday) or allowable emission levels from similar sources using Reasonably Available Control Technologies (RACT) Citation 40 CFR 52
Verify through emission estimates and dispersion modeling that hydrogen sulfide emissions do not create an ambient concentration greater than or equal to 010 ppm Citation 40 CFR 61
Verify that emissions of mercury vinyl chloride and benzene do not exceed levels expected from sources in compliance with hazardous air pollution regulations Citation 40 CFR 61
Table 7-3 Page 17 of 18 See comment for Page 12 of 18 regarding hydrogen sulfide emissions (last box in Requirement column)
38 Assessment of Additional Data Requirements
Page 8-5 1(4 sect83 The Phase 1A Remedial Investigation did not produce Level III or IV quality data for sediments in the Drainage Pond an area which may contain some of the highest concentrations of site contaminants As such this pond may represent a significant exposure point since it receives discharge from the landfill underdrain and it can be readily contacted by surface receptors both human and ecological The PCB results generated by the McLarenHart onsite mobile laboratory are Level II data quality (as stated in the Phase 1A RI Table 4-1) and are not appropriate for quantifying human health or ecological risks Without Level III or IV data human health ecological risks cannot be evaluated Therefore a minimum of three sediment samples must be submitted for full TCLTAL analyses to characterize the Drainage Pond The text needs to be revised to incorporate this data gap and appropriate corrective action
Page 8-6 ^5 sect85 It is stated that leachate samples were collected during low flow conditions It is also important to obtain information on high flow contributions Although contaminants may be concentrated during low flow condition high flow conditions may generate the presence of additional contaminants and potentially contribute higher concentrations
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
23
than at low flov due to a flushing effect of cortarinant pools within the landfill
Pace 8-7 52 sect86 The hydraulics of flow in the landfill needs to be better understood as noted in previous ccrnents The effects of the drainage system on ground water flow needs to be evaluated
Page 8-9 sect89 The reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Either sediment quality data for the reference sites needs to be collected or the large uncertainty associated with the suitability of the reference samples needs to be clearly recognized in the comparison with the onsite samples
39 Appendices
Appendix B
Include original meteorological data in the appendix So that EPA can reproduce the calculations The calculations must demonstrate how the Pasquil stability class was determined
Appendix C
Page 1 laquo[2 sect10 Include the field sample chain of custody records for TO-2 and TO-4 were in Appendix O as received
Also include copies of the meteorological data in Attachments or Appendix O
Laboratory reports for the method TO-2 samples must also be included
Table 3-1 The method limit of detection (MDL) column only shows MDLs for vinyl chloride xylene and 1122-tetrachlorethane provide the MDLs for the other VOC compounds In addition is the reported MDL for PCBs (000007 - 00009) ugm3) for all the listed Aroclors
Page 11 54 sect32 The text indicates that sample volumes were between 20 and 30 liters Method TO-2 recommends a maximum sample volume of 20 liters for vinyl chloride to prevent breakthrough of the media Sampling data sheets for TO-2 samples located in Attachment A indicate two samples in excess of 30 liters TS-2R 102392 54 liters and TS-R5 102792 413 liters Explain in the text how the collection of the higher volume may effect data quality
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
24
Page 12 laquo[1 sect33 Sarple containers should be glass and rhe sarples should be maintained at ~0degC until analysis Describe in ~he cext how samples were shipped ie packed in coolers with ice or cold packs Laboratory sample logs in Appendix O do nor indicate the temperature of samples or packaging In the future indicate the temperature of samples or packaging Also how were samples stored until shipment to the laboratory
Table 4-1 The barometric pressure column has the reported data in mm Hg The acrual data appears to be in millibars Please correct
Page 24 [2 sect50 Provide documentation for sample preservation
Page 25 sect51 Provide TO-2 analytical data in Appendix 0 Table 6-1 data cannot be reproduced or evaluated without TO-2 lab analysis or lab reports
Page 28 ^1 sect61 Correct the discrepancy in the text references Table 5-1 rather than 6-1
Page 45 [1 The exposure assessment does not comply with current risk assessment guidance (Supplemental Risk Assessment Guidance for the Superfund Program 1989) because it does not evaluate future land use (potentially residential) This limited risk assessment underestimates risks since a significant exposure population was not considered To comply with guidance the risk assessment must estimate risks to potential site residents
Page 50 53 The risk characterization is incomplete because it failed to evaluate noncarcinogenic effects Correct this deficiency
Table 6-2 The analytical data contained in Appendix O appears to be incomplete The sample runs for Lab No 171729 could not be located
The values for P2-1 and TS-2 for 1023-2492 are not reported as estimated values although the field blank is reported as an estimate
Results for Aroclor 1242 on 1030-3192 are considered estimates in Section 52 but the values in Table 6-2 are not so noted Correct Table 6-2 to reflect that the values are estimates
Indicate that Sample TS-2 1023-24 has no notification of a motor failure
Table 7-1 and Table 7-2 For the column that shows the Vermont Hazard Ambient Air Standards (HAAS) for the compounds of interest indicate whether the values are representative of 8shyhour 24-hour or annual average standards This also holds true
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
25
fcr the data Reported for the USEPA - 1938 Nonnerhane Organic Compound Sampling Program conducted in Burlington VT
The sampling duration for the VOC samples range from 6 to 8 hours and for PCB sarples it was 24-hours A direct comparison of the VOC and PCB data to the Vermont Hazard Ambient Air Standards (HAAS) representative averaging time is similar to the sampling data averaging tines
Attachment A Sample Chain of Custody and Documentation Sheets
1 Units on PUF sampler (TO-4) calibration forms are labeled as standard-cubic meters (SCM) per minute but units on calibration curves for the samplers are listed as cubic feet per minute Correct this discrepancy
2 Tire and ambient temperatures are not filled in on several calibration forms If it is possible to correct this deficiency this should be done In the future calibration forms must bullinclude time and ambient temperatures
3 Post calibration data for TO-4 on 1024 are incomplete Include flow rates completed Also why are the percent difference values identical to calibration on 1023
4 Include post-calibration data for TO-4 samples collected on 1030-3192
5 Include calibration data for PVF sample timers
6 Indicate on the attachment whether clock time or a sample time was used to calculate volume sampled
7 List corrective actions used for times listed as inoperative on calibration forms
8 Include a note on Table 6-2 to indicate that the motor failed on the sampler at location TS-2 1023-24
9 Include a note on the TO-4 sampler data forms for times that venturi readings were taken Also mention whether or not samples were equipped with recorders to document operational periods and flow rates
Appendix D
Page 8 laquoJ1 Section 22 The first sentence in this paragraph appears incomplete Please correct this typographical error
Page 8 [2 Section 23 Clarify the connection between the diversion ditch and surface water drainage
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
26
Section 21 Ccrducting the vegetative survey in the late fall prccably contributed tc an under representation of herbaceous annual species Clarify why the vegetative transects performed bullbullere net located in areas immediately adjacent to the landfill and why no transect was performed south of the landfill Provide information regarding the length of each transectquad and the rationale for selecting the locations
Page 13 53 Section 33 Identify the smap trap areas and trap effort to better define habitat usage Provide mere details and information regarding the scope of the population survey
Page 15 ^2 Section 34 The seasonality of the survey is an inpcrtant consideration Species indicated are predominantly winter migratory residents and do not represent potential spring migrants and breeding songbirds Describe the specific areas bull-here avian species were identified
Page 15 laquoI2 Section 35 Although it is noted that attempts were made to identify reptileamphibians the qualitative survey performed appears to be very cursory and may have potentially missed numerous species
Page 17 f3 Furnace Brook was reportedly used as a macrobenthic invertebrate reference sample location for lotic environments The Characterization Report states that the benthic sampling location was at the point where the brook flows under Park Street Indicate whether this sampling location was located on the upgradient or downgradient side of Park Street
Page 17 f3 The report states that the reference macroinvertebrate sampling locations (pond and stream) do not have watersediment quality data available The absence of this data limits the suitability of these reference stations as comparisons between the onsite samples and reference samples may be attributable to a wide variety of unknowns Address this issue by either collecting sediment quality data for the reference sites or clearly recognize the large uncertainty associated with the suitability of the reference samples in the comparison with the onsite samples
Section 36 It is not stated how the benthic survey was performed Specifically the number of locations sampled the level of effort etc Also using a seine for benthic assessment is not generally acceptable In order to verify if two streampond habitats are comparable some form of rapid bioassessment protocols must be performed
Page 18 Section 37 Although the field execution of the wetland delineation appears to be thorough the field data sheets with regards to the plant community and final rationale for wetland verification are incomplete Include the completed field data sheets in the Draft RI Report
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
27
Page 23 laquo[1 Te report scares that the topography of the landfill drops off steeply to the rorth south and west vith a mere gradual incline to the ves- Please correct this apparent error
Page 35 Section 423 There is no indication as to the relative numbers of marrrals observed To state that all rarimals observed vere distributed en a uniform basis throughout the site does not provide a very useful interpretation of site habitat use conditions Report the total trap nights sex of individuals and reproductive status for the voles captured en the landfill Also what species were observed in Pond A
Page 38 laquo[1 Section 424 A macroinvertebrate survey was conducted of Ponds B and C It is unclear why the Drainage Pond -bullas also not sampled for -acroinvertebrates as this habitat would appear to be irost at risk fron contaminants originating from the landfill Provide a rationale in the text for not sampling this aquatic environment
Page 33 2 Section 424 The report states that three ponds are located on the site However there are apparently four ponds present including the Drainage Pond Please correct this discrepancy
Page 38 53 Section 424 Since Pond A is about the sane size as Pond B it may be the functional habitat for aquatic species during specific life stages For this reason this habitat should also be investigated Stating that no behavioral or physiological abnormalities were observed is notable but should be considered as strictly qualitative and not indicative of any potential sublethal or lethal effects to the aquatic community include more detail regarding the surface water connection between Hewitt Brook and Pond C is unclear
Page 43 fl Cooks version of the Chandler Biotic Index is stated in the report as being primarily applicable to lotic environments although it is useful in comparing data from lentic environments when one of the locations is known to be free from environmental degradation Note in the text that neither the onsite or reference macrobenthic invertebrate sampling locations have been documented as being free from environmental degradation
Page 52 51 The report states that abundant pollution of intolerant macroinvertebrate species are present Please correct this typographical error
Page 56 ^3 Section 428 The mink is highly sensitive species to PCB contamination and the wetlands surrounding the landfill appear to be potential good habitat for it Therefore it would be a very useful indicator species to include in a risk assessment for the site
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
28
Page 62 2 4284 Hall and Mulhern are not cited With the presence of numerous wetlands it is appropriate that an arphibian species be included in the risk assessment
Page 70 51 Elevated PCS levels in sediments are often associated with the total organic carbon (TOC) content of the sediments In fact TOC is correlated with the bioavailability of organic nonshypclar hydrophobic contaminants within the sediments Was the TOC of sediments within the different aquatic environments of the site was quantified Provide TOC and other site-specific data (eg surface water hardness) for each of the aquatic environments identified on the site
Page 72 Section 70 Qualitative Risk Characterization The rrarmals that were captured onsite may in fact appear to be healthy However sublethal effects rarely manifest themselves in readily observable physiological symptoms It is more likely that bioaccumulation of contaminants may be occurring without gross observable abnormalities and that subtle internal effects may be present The availability of the sediments in the numerous wetland areas is not known Therefore it is difficult to pass judgement on whether small mammals may be utilizing them on a widespread basis
Lead mercury arsenic and manganese were all reported as exceeding background levels in several sediment andor soil locations These inorganic constituents may be potentially impacting biota if readily available through any of the exposure routes mentioned in the text Manganese levels are noticeably elevated in several locations that may be impacting benthic biota It is not acceptable to discount sediment levels based on an absence of manganese in the surface water samples at the same locations Although there is no AWQC for manganese toxicity data in the AWQC text states that upper limit values range around 1000 ppm This value is exceeded in at least the four locations described as above background The use of a benthic survey to justify the absence of adverse effects is not totally justified in light of the fact that sampling locations are not stated and may not correspond to elevated and background levels of contaminants It is also stated that Ponds A and B were sampled for benthic assessments Pond A was not sampled but should be assessed
It is clear that PCB contamination in the drainage pond area is of primary concern however it may not be the only area of ecological concern The inorganic levels present in areas east of the landfill require further investigation concerning ecological impacts In reference to the PCB contamination ecological risks associated with the elevated levels of PCBs should be evaluated for indicator species suggested in the text with the inclusion of mink
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
29
Page 73 ^2 Surface soil PCS cpncentrations of 1 ppm and 3 ppr are listed in the report as being protective of mammalian and avian receptors respectively However the source cited (Maughan 1993) is not provided in the reference section Include this reference in the text
Page 74 ^4 The report states that the evaluation of the macroinvertebrate community within the onsite ponds (A and 3) suggest that these habitats are not under stress Revise this statement as macroinvertebrate sampling was not conducted within Pond A
Attachment E Wetlands Data Summary Sheets are provided in this attachment The data forms provided are not consistent with wetland delineation data forms used by the US Army Corps of Engineers (New England Division) Complete the data forms and include the necessary information required to verify the delineation If remedial measures are proposed within or adjacent to wetland areas it may be necessary to complete the correct delineation data forms
Appendix F 1 EPA requires that undiluted sampling results be reported as well as
Appendix J
1 Revise the figure titled Shallow Groundwater Elevation Contour Map - 42693 The 920 foot contour line is drawn east of the Well - SOL when it should be to the west side
2 As noted in general comments EPA believes that flow in the landfill is more complicated than is depicted in the contour maps and may be affected by the underdrain system The maps must be reevaluated
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
30
ATTACHMENT III
EPA SPLIT SAMPLE COMPARISON WITH SETTLING PARTIES SAMPLES
EPA contractor collected 14 split samples during the Phase 1A field activities A cross reference list of split sample locations and parameters analyzed in provide in Table 1 enclosed
The objective for split sairple collection was to quantitatively ccrpare analytic results obtained by the Settling Parties to those from the EPA split samples to determine if a usability problem exists with the Settling Parties data set
The EPA split samples were analyzed through the Routine Analytical Services (RAS) and Special Analytical Services (SAS) programs of the EPA Contract Laboratory Program (CLP) All sarples were analyzed for TCL organics and TAL metals Cne sarple MW-2-3 was also analyzed for low concentration volatile organics
The Settling Parties samples were analyzed by Aquatec Laboratories in Burlington Vermont for TCL organics and TAL metals using the CLP statement of work
10 Procedure
EPA contractor TRC has developed a comparison procedure that calculates the relative percent difference (RPD) of detected compounds in each data set A quantitative comparability goal which originated from Region I data validation guidance for the evaluation of field duplicates is then applied to the calculated RPD to evaluate the comparability of the split samples The comparability goal for organic results and inorganic results above five times the contract required detection limit (CRDL) is an RPD of 30 percent for water samples and RPD of 50 percent for soilsediment samples For inorganic results where one or both split sample results are below five times the CRDL the water comparability goal is an absolute difference of less than twice the CRDL and the soil comparability goal is an absolute difference of less than four times the CRDL
Accordingly the Settling Parties and EPA split data were quantitatively compared by applying the above criteria to the results of the split sample analyses For results that were outside the quantitative comparability goal professional judgement was used to determine if a data useability problem existed Generally the data were considered to have a useability problem if the following additional conditions were encountered 1) the EPA analyte was detect at a concentration above the CRQLCRDL and was not detected by the Settling Parties and 2) the EPA result was greater than the Settling Parties result and both results were above the CRQLCRQL
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
31
20 RESULTS
Quantitative split sarpie comparisons for volatile and se^ivolatile organic pesricideCB and inorganic analyses are presented in Appendix A enclosed
The overall comparability for the two data sets was variable The organic analyses generally had acceptable ccrrparability bullbullhereas the comparability of the inorganics was less acceptable As indicated in Table 2 EPA determined 10 of rhe 49 split sample analyses to have inadequate data comparability The following is a brief description of the incomparable analyses
1 Volatile organic results for the EPA groundwater split sample MW-6-1 and its field duplicate MW-6-1 dup) were compared to the Settling Parties results Results for 11-dichloroethane 12shydichloroethene (total) benzene and toluene were outside the comparability goal for both the sample and the field duplicate and several EPA results were approximately three times the Settling Parties results
2 In the semi-volatile analysis of split sample LEACH(UD)-01 several PAHs as well as dichlorobenzene and trichlorobenzene were detected in the EPA sample at concentrations that were approximately three times the Settling Parties results Additionally EPA detected above CRDL concentrations of acenaphthene fluorene and butylbenzylphthalate that were not detected by the Settling Parties
3 EPA detected 44-DDE and gamma-chlordane in sample LEACH(UD) shy01 at concentrations that were approximately four times the concentration detected in the Settling Parties analysis EPA detected 44-DDT and arochlor-1242 in this sample at concentrations of 270 ugL and 150000ugL The Settling Parties results for these analytes were rejected the Settling Parties reported a result for arochlor-1248 at a concentration of 63000ugL that was not detected by EPA It is probable that EPA and the Settling Parties detected arochlors were the same cogeners and one of the laboratories misidentified the detected cogener
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
32
4 In the folTowing water sarples EPA detected above CRDL concentrations of -etals that were greater than the Settling Parties results
Sample Analyte EPA Result Settling (ug1) Parties Result j
(ugL)
LEACH (UD) -01 aluminum 1580 737
LEACH (UD) -01 arsenic 174 111 |
LEACH (UD) -01 iron 30400 19400
LEACH (UD) -01 lead 685 87
LEACH (UD) -01 manganese 295 207
LEACH (UD) -01 zinc 2600 1270
MW-6-3 aluminum 5550 592
MW-6-3 iron 3420 1110
Additionally metals were detected in the following EPA ground water split samples at concentrations above the CRDL but were not detected by the Settling Parties
Sample Analyte EPA Result (ug1)
MW-2-3 zinc 407
MW-6-1 zinc 209
MW-6-3 chromium 138
MW-6-3 lead 86
MW-6-3 (dup) zinc 318
Metals were also detected in the following EPA sediment split samples at concentrations above the CRDL but were not detected or were rejected by the Settling Parties
Sample Analyte EPA Result (ugL)
SED-02 cadmium 11
SED-02 lead 19 1
A quantitative comparison was not performed on soil sample SS-06 because it was not analyzed by the Settling Parties laboratory Several pesticidePCBs were detected in the EPA split sample at
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set
33
concentration above the CRQL These compounds include aldrin at 130 ugL alpha-chlordane at l3o ugL and gamma-chlordane at 34 ugL and arochlor-1254 at 3700 ugL Metals including aluminum arsenic barium calciun chromium copper iron lead magnesium manganese mercury nickel potassium and zinc were also detected at concentrations above CRDL in EPA results for SSshy06
30 EPA DETERMINATIONS
1 All analyses exhibiting inadequate comparability listed in the texttables in number 4 above must be confirmed for accuracy
2 Include the results for soil sample SS-06 in the RI appendices or provide an explanation for the omission of this sample
3 Include notation within the summary tables and results appendices describing the above mentioned discrepancies for future users of the Settling Parties data set