fifth five-year review report
TRANSCRIPT
Bryan Olson, irector
FIFTH FIVE-YEAR REVIEW REPORT FOR BFI ROCKINGHAM LANDFILL SUPERFUND SITE
ROCKINGHAM, VERMONT
Prepared by
U.S. Environmental Protection Agency Region I
Boston, Massachusetts
Date Superfund and Emergency Management Division
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Table of Contents LIST OF ABBREVIATIONS & ACRONYMS ......................................................................................... ii
I. INTRODUCTION ................................................................................................................................... 1
Site Background ...................................................................................................................................... 1
Five Year Review Summary Form ......................................................................................................... 2
II. RESPONSE ACTION SUMMARY ...................................................................................................... 3
Basis for Taking Action .......................................................................................................................... 3
Response Actions .................................................................................................................................... 3
Status of Implementation ........................................................................................................................ 4
IC Summary Table .................................................................................................................................. 6
Systems Operations/Operation & Maintenance ...................................................................................... 6
III. PROGRESS SINCE THE LAST REVIEW.......................................................................................... 6
IV. FIVE-YEAR REVIEW PROCESS ...................................................................................................... 8
Community Notification, Involvement & Site Interviews ...................................................................... 8
Data Review ............................................................................................................................................ 8
ROD Contaminants of Concern .............................................................................................................. 9
1,4-Dioxane and Per- and Polyfluoroalkyl Substances (PFAS) Monitoring ........................................ 10
Extent of Contamination ....................................................................................................................... 10
Site Inspection ....................................................................................................................................... 11
V. TECHNICAL ASSESSMENT ............................................................................................................ 12
QUESTION A: Is the remedy functioning as intended by the decision documents? ........................... 12
QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives used at the time of the remedy section still valid? ............................................................... 13
QUESTION C: Has any other information come to light that could call into question the protectiveness of the remedy? ............................................................................................................... 17
VI. ISSUES/RECOMMENDATIONS ..................................................................................................... 17
Other Findings ...................................................................................................................................... 18
VII. PROTECTIVENESS STATEMENT ................................................................................................ 18
VIII. NEXT REVIEW............................................................................................................................... 18
APPENDIX A – REFERENCE LIST APPENDIX B – FIGURES APPENDIX C – DATA TABLES APPENDIX D – SITE BACKGROUND APPENDIX E – CHRONOLOGY APPENDIX F – PUBLIC NOTICE PRESS RELEASE APPENDIX G – INTERVIEW SUMMARY APPENDIX H – SITE INSPECTION CHECKLIST
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LIST OF ABBREVIATIONS & ACRONYMS
ARAR Applicable or Relevant and Appropriate Requirement AST Aboveground Storage Tank CD Consent Decree CERCLA Comprehensive Environmental Response, Compensation, and Liability Act, 42 U.S.C. 9601 et seq. CFR Code of Federal Regulations COCs Contaminant of Concern DSI Disposal Specialists, Inc. EPA United States Environmental Protection Agency ESD Explanation of Significant Differences FYR Five-Year Review ICs Institutional Controls IGCL Interim Groundwater Cleanup Levels NCP National Oil and Hazardous Substances Pollution Contingency Plan, 40 C.F.R. Part 300 ND Non-detect NPL National Priorities List NTCRA Non-Time Critical Removal Action O&M Operation and Maintenance PFAS Per- and Polyfluoroalkyl Substances PFHpA Perfluoroheptanoic acid PFHxS Perfluorohexanesulfonic acid PFNA Perfluorononanoic acid PFOA Perfluoroctanoic acid PFOS Perfluorooctane sulfonic acid PRP Potentially Responsible Party QAPP Quality Assurance Project Plan RAO Remedial Action Objective ROD Record of Decision RPM Remedial Project Manager SOW Statement of Work TSA Technical Services Assessment UST Underground Storage Tank UU/UE Unlimited Use/Unrestricted Exposure VTANR Vermont Agency of Natural resources VTDEC Vermont Department of Environmental Conservation VI Vapor Intrusion VOC Volatile Organic Compound
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I. INTRODUCTION The purpose of a Five-Year Review (FYR) is to evaluate the implementation and performance of a remedy in order to determine if the remedy is and will continue to be protective of human health and the environment. The methods, findings, and conclusions of reviews are documented in five-year review reports. In addition, FYR reports identify issues found during the review, if any, and document recommendations to address them. The U.S. Environmental Protection Agency (EPA) prepares FYRs pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 U.S.C. Section 9621, consistent with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) (40 CFR Section 300.430(f)(4)(ii)), and in consideration of EPA policy. This is the Fifth FYR for the BFI Rockingham Landfill Superfund Site. The triggering action for this statutory review is the September 2014 completion date of the previous (Fourth) FYR. The FYR is required because hazardous substances, pollutants, or contaminants remain at the Site above levels that allow for unlimited use and unrestricted exposure (UU/UE). The Site consists of one Operable Unit, which is addressed in this FYR. The BFI Rockingham Landfill Superfund Site Fifth Five-Year Review was led by Kevin Heine, EPA Region 1 Remedial Project Manager (RPM). Other Region 1 participants included Courtney Carroll, risk assessor, and Sarah Meeks, attorney; and Michael Smith, Vermont Department of Environmental Conservation (VTDEC) site manager. CES, Inc. provided technical assistance to EPA. Documents reviewed in support of this FYR are listed in Appendix A. Figures are shown in Appendix B and tables in Appendix C. The review began on December 20, 2018.
Site Background The BFI Rockingham Landfill Superfund Site (the “Site”), also known as the Disposal Specialists, Inc. (DSI) Landfill and the BFI Sanitary Landfill, is located along U.S. Route 5, locally identified as Missing Link Road, in the Town of Rockingham, Windham County, Vermont as shown on Figure 1, Appendix B. The 17-acre solid waste landfill is located within a 120-acre parcel of property owned by BFI Waste Systems of North America, LLC. The landfill is located approximately 500 feet west of and 200-feet higher than the nearby Connecticut River. Abutting the landfill to the south and east is an approximately 12-acre area of the Site that includes the former operations and hauling facility (office building, garage, former solid waste transfer area and now vacant former facility manager’s house), the landfill gas management system; and all or parts of six parcels located east of Missing Link Road, four of which have residences on them, as shown on Figure 2. The landfill is situated on a glacial terrace located along the west side of the Connecticut River. Geological cross sections prepared as part of the RI/FS are included as Figures 3 and 4. The majority of the waste within the landfill is underlain by a relatively thin layer of sand deposits overlying varved lacustrine deposits comprised of interbedded clay and silt. The lacustrine deposits and bedrock are generally separated by a sandy glacial till unit. Overburden is approximately 200 feet thick on the southeast side of the landfill, with little or no overburden present on the northwest side of the landfill. Bedrock under the Site consists of moderately fractured black and gray phyllite and slate of the Littleton Formation. Overburden and bedrock groundwater flows are primarily east to southeast from upland areas of the Site to the Connecticut River. The BFI Rockingham Landfill Superfund Site was placed on the National Priorities List (NPL) in 1989. In 1993, the U.S. Environmental Protection Agency (EPA) signed an Action Memorandum to initiate a Non-Time Critical Removal Action (NTCRA). The NTCRA include the placement of a multi-layer cap over the landfill; expansion of the existing landfill gas management system; operation and maintenance of the Route 5 Stabilization and Seepage Control System shallow groundwater collection trench; and institutional controls (ICs). In 1994, EPA signed a Record of Decision (ROD) selecting monitored natural attenuation and ICs as the long-term cleanup approach for the restoration of contaminated groundwater. Construction of the NTCRA action was completed in
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July 1995 and EPA certified the Completion of Work Report in September 1996. Refer to Appendix D for additional Site background information and Appendix E for a more complete Site chronology.
FIVE YEAR REVIEW SUMMARY FORM
SITE IDENTIFICATION
Site Name: BFI Rockingham Landfill Superfund Site
EPA ID: VTD980520092
Region: 1 State: VT City/County: Rockingham / Windham
SITE STATUS
NPL Status: Final
Multiple OUs? No
Has the site achieved construction completion? Yes
REVIEW STATUS
Lead agency: EPA [If “Other Federal Agency”, enter Agency name]: Click here to enter text.
Author name (Federal or State Project Manager): Kevin Heine
Author affiliation: EPA Region 1
Review period: 12/20/2018 - 9/30/2019
Date of site inspection: 6/12/2019
Type of review: Statutory
Review number: 5
Triggering action date: 9/30/2014
Due date (five years after triggering action date): 9/30/2019
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II. RESPONSE ACTION SUMMARY
Basis for Taking Action DSI and BFI-VT, the two Potentially Responsible Parties (PRPs) at the Site, initiated negotiations with EPA during the spring of 1992 to conduct a Remedial Investigation and Feasibility Study (RI/FS) in accordance with NCP requirements. A Remedial Investigation (RI) was performed at the Site from 1992 to 1994 (Balsam 1993 & 1994). The RI identified the landfill as the source of contamination found in bedrock and overburden groundwater downgradient of the Site. Surface water in drainage ditches along Route 5 was found to also contain Site-related contaminants. The information collected during the Remedial Investigation and Feasibility Study (RI/FS) was used to conduct Human Health and Ecological Risk Assessment. The results indicated that an unacceptable carcinogenic and non-carcinogenic risk would result from ingestion of bedrock groundwater. This was a hypothetical exposure scenario since no individuals were ingesting contaminated groundwater at the Site due to the provision of an alternate water supply. The carcinogenic risk results primarily from arsenic and vinyl chloride. Arsenic and manganese represented the majority of the non-carcinogenic risk at the Site under both average and maximum exposure scenarios. Constituents that exceeded a federal safe drinking water maximum contaminant level (MCL) or maximum contaminant level goal (MCLG) in bedrock groundwater during RI sampling at the Site include: antimony, arsenic, barium, benzene, bis (2-ethylhexyl) phthalate, chromium, nickel, pentachlorophenol, tetrachloroethylene, and vinyl chloride. In addition to these substances, exceedances of the State of Vermont groundwater standards for 2-butanone, lead and xylene were also reported. Based on the Ecological Risk Assessment and further sampling results as discussed in the ROD, EPA concluded that adverse effects on the Connecticut River were not likely.
Response Actions Two CERCLA cleanup actions have been implemented at the Site. The first was a non-time critical removal action (NTCRA) documented in a 1993 Action Memorandum. The NTCRA included construction of the multilayer landfill cap and the Route 5 Slope Stabilization and Seepage Control System (Route 5 System). The Route 5 System consists of a shallow overburden groundwater collection trench. The trench is bounded by sheet piling and was designed to intercept a limited area of impacted overburden groundwater that historically discharged at the top of ravines located adjacent to Route 5. This water is collected in an aboveground storage tank (AST) for offsite treatment and disposal. Other NTCRA components included the expansion of the gas extraction system and ICs to protect the cap. The multilayer cap was constructed with a slope of 3:1 and included: a gas vent layer, a compacted low permeability native soil layer, a very low density, polyethylene geomembrane, a stormwater drainage tire chip layer, vegetative support soil and topsoil. The second cleanup action described in the ROD called for the natural attenuation of groundwater, continued maintenance of the NTCRA, long-term monitoring, and ICs. The ROD established the following remedial action objectives (RAOs). Landfill (Source Area) Remedial Objectives:
Prevent, to the extent practicable, the potential for water to contact or infiltrate through the debris mass; Prevent, to the extent practicable, the generation of landfill seeps and the migration of landfill-impacted
surface water into the Connecticut River; Control landfill gas emissions so methane gas does not present an explosion hazard; prevent, to the extent
practicable, the inhalation of landfill gas containing hazardous substance, pollutants, or contaminants; and meet state and federal air standards;
Prevent, to the extent practicable, the migration of contaminated groundwater beyond the points of compliance by controlling the source area;
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Minimize the potential for slope failure of the debris mass associated with the multi-layer landfill cap or any further action; and
Prevent, to the extent practicable, direct contact with and ingestion of debris within the landfill and beneath the landfill.
Groundwater Remedial Objectives:
Prevent, to the extent practicable, the ingestion of landfill-impacted bedrock groundwater exceeding EPA Safe Drinking Water Act Maximum Contaminant Levels (MCLs), Vermont Primary Groundwater Quality Standards, or in their absence, the more stringent of an excess cancer risk of 1x10-6 for each compound or a hazard quotient of 1 for each non-carcinogenic compound by an individual who may use the bedrock groundwater within the area of landfill-impacted groundwater or within an area that could become impacted as a result of pumping activities; and
Restore the bedrock groundwater at the edge of the Waste Management Unit (solid waste boundary shown on Figure 2) to: MCLs, Vermont Primary Groundwater Quality Standards, or in their absence, the more stringent of an excess cancer risk of 1x10-6 for each compound or hazard quotient of 1 for each non-carcinogenic compound.
Surface Water (Ecological) Remedial Objectives:
Protect off-site surface water by preventing the occurrence of landfill impacted seeps; Meet federal and state ARARs for any surface-water discharge to the Connecticut River; and, Provide long-term monitoring of the surface water and sediments of the section of the Connecticut River
adjacent to the landfill to assure that no landfill-related impacts occur in the future.
Status of Implementation The design of the NTCRA was initiated in October 1993 and completed in July 1994. The expansion of the gas extraction system and Site preparation activities were completed in May 1994. The multi-layer landfill cap was completed in July1995. Surface water (stormwater) control systems were completed by August 1995 and a vegetative cover was established by October 1995. EPA, VTDEC and the oversight contractor performed a final inspection in May 1996 and the cap and all related appurtenances were determined to be constructed according to design, with a well-established vegetative cover. The construction activities and completion were documented in a Completion of Work Report that was approved by EPA in September 1996. The report documented the completion of the NTCRA and the initiation of Post-Removal Site Control / Operation and Maintenance by the PRPs. In 1996, DSI and BFI-VT entered into a Consent Decree (CD) (Civil Action #2:96-CV-309) with EPA to perform the remedial actions required under the ROD. The remedy memorialized in the 1994 ROD identified Monitored Natural Attenuation (MNA) for groundwater, ICs, and maintenance of the NTCRA. The ROD anticipated that Interim Groundwater Cleanup Levels (IGCLs) would be achieved 15 years after completion of the NTCRA. Due to the limited extent and low yield, overburden groundwater was not considered to be a potential drinking water source or a current or future human exposure pathway; therefore, IGCLs were not established for overburden groundwater. Long-term monitoring results did show significant improvements in groundwater and surface water quality following construction of the NTCRA. However, by 2008, long-term monitoring results indicated IGCLs for benzene, total xylenes, tetrachloroethene, methylene chloride, 2-butanone, vinyl chloride, arsenic, manganese, barium and chromium may not be met for bedrock groundwater at some locations within the timeframe estimated in the ROD. Further, EPA and BFI-VT jointly concluded that meeting arsenic and manganese IGCLs would be problematic due to the naturally-occurring presence of these metals in bedrock fractures.
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Accordingly, field investigation activities were performed and the LTMP was modified during 2009 and 2010 in support of a TI evaluation. Based on the evaluation completed, EPA determined that a TI waiver was not the preferred method of addressing the ROD requirement for ground water restoration in the bedrock aquifer. An Investigation Plan (Summit 2012) was subsequently prepared that identified additional response actions necessary to ensure the continued protection of human health and the environment. EPA issued an approval of the Investigation Plan in a letter dated February 16, 2012. The additional response actions implemented as per the Investigation Plan are summarized below:
• The Conceptual Site Model (CSM) was updated (Summit 2012c). • Potential vapor intrusion pathways related to structures located downgradient of the landfill
(Summit 2012d, 2014b) were evaluated. • Binding Water Supply Agreements between BFI-VT and downgradient property owners were
recorded on property deeds for BFI-VT to supply potable water to downgradient landowners and to operate and maintain the water supply system until the EPA and VTDEC determine groundwater restoration has been completed (Summit 2014b).
• Confirmed that the existing water supply system (formally identified as the DSI Missing Link
Road Non-Public Water Supply System) installed to serve downgradient residences substantially meets existing codes for public water lines. The system is classified as a Non-Public Water System that does not need a State permit due to the limited number of users and connections.
• The Groundwater Reclassification Zone boundary, originally reclassified in 2009, was amended
by VTANR in 2013 to expand the boundary northward to include two additional properties due to inaccurate survey coordinates utilized for the 2009 reclassification.
• The groundwater quality monitoring program was reviewed to determine what monitoring was
needed until cleanup criteria are met and the LTMP was subsequently updated, with a revised monitoring program that commenced in 2015.
An Explanation of Significant Differences (ESD) for the Site was completed in September 2014. The ESD addressed why the bedrock groundwater cleanup at the site had not met the IGCLs established in the ROD and revised the timeframe for the restoration of bedrock groundwater to the IGCLs to between 2050 and 2070, and achievement of the IGCLs established in the ROD for VOCs by 2025. It also revised the IGCLs for arsenic and lead because of changes in federal and state standards for those chemicals and it documented the implementation of the additional ICs at the Site. There have been no new remedial activities implemented at the Site since the 2014 FYR, other than the installation of a candlestick flare in August 2017. The new flare replaced the original enclosed flare that required a relatively large amount of gas to burn, resulting in more frequent flare shutdowns as the landfill matures and generates lower amounts of landfill gas. Because the new candlestick flare requires less gas to burn, it operates more continuously and therefore provides better long-term control of potential gas migration and landfill odors. Institutional Controls ICs are required at the Site to ensure the protectiveness of the remedy and were identified as a remedy component in the ROD. The restrictions required by the ICs appear to be in full force and effect as determined by the IC evaluation activities discussed below. No further ICs or changes to the current ICs are recommended at this time.
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IC Summary Table Table 1: Summary of Implemented ICs
Media, engineered controls, and areas that do not support UU/UE based
on current conditions
ICs Needed
ICs Called for in the Decision
Documents
Impacted Parcels
(see Figure 2, Appendix B
IC Objective
Title of IC Instrument
Implemented and Date (or planned)
Groundwater Yes Yes
PRP-owned Parcels:
4-505-894, 4-505-890, 4-107-032.
Rights of access and groundwater
use restriction
Grant of Environmental Restrictions &
Right of Access, June 1996
Groundwater Yes Yes
PRP-owned Parcels:
4-505-894, 4-505-890, 4-107-032.
Parcels owned by others: 4-107-014, 4-505-897, 4-107-012, 4-107-010, 4-107-006.
Reclassified groundwater from Class III to Class IV, prohibiting
future public water supply
development and use
VTANR Reclassification
Order (March 10, 2009, amended November 6,
2013)
Systems Operations/Operation & Maintenance Operation, maintenance and monitoring activities are currently being implemented by the PRPs. Monitoring and maintenance reports are submitted to EPA and VTDEC for review. The operation, maintenance and monitoring activities focus on:
• Inspecting the vegetative cover of the cap and repair of any erosion; • Balancing the landfill gas extraction system and repair of any wells or conveyance lines; • Shipping leachate to an off-site treatment facility; • Collecting samples to monitor the restoration of groundwater; and • Providing potable water to four properties on River Front Drive and maintaining the water line and
system. Operation and maintenance (O&M) activities conducted during the most recent 5-year review period included regular operation and monitoring of the private water line system used to provide off-site properties with drinking water; and regular operation and monitoring of the landfill gas management system, Route 5 Seepage Control and Stabilization System, and the leachate collection system. Ongoing maintenance of the landfill cap includes mowing and removal of vegetation from the stormwater runoff ditches and let downs.
III. PROGRESS SINCE THE LAST REVIEW This section includes the protectiveness determinations and statements from the last FYR as well as the recommendations from the last FYR and the current status of those recommendations.
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Table 2: Protectiveness Determinations/Statements from the 2014 FYR
OU # Protectiveness Determination
Protectiveness Statement
1 (Site Wide) Short-term Protective The remedy currently protects human health and the environment because:
There is no current exposure of Site related contaminants to humans or the environment at concentrations that would represent a health concern;
The Site is secure with fencing and locked access gates to minimize unauthorized access to the closed landfill.
The landfill cover system prevents exposure to the waste material and contaminants within the landfill;
The private water line system serving four downgradient properties has eliminated groundwater use within the area impacted by the landfill;
Ongoing monitoring has demonstrated that Connecticut River water quality is not being adversely affected;
Landfill gas is collected and treated by the extraction system and enclosed flare;
The land use restriction for the Site prevents any use of the land that would result in an exposure to hazardous substances, pollutants, or contaminants; and
VT ANR has reclassified the groundwater beneath the Site from a Class III to a Class IV aquifer, which prohibits potable use.
However, in order for the remedy to be protective in the long-term, the on-going vapor screening level assessment needs to be completed. EPA will monitor whether additional institutional controls or other measures are needed to ensure groundwater use remains restricted at the Site.
Table 3: Status of Recommendations from the 2014 FYR
OU # Issue Recommendations/ Follow-up Actions
Party Responsible
Oversight Party
Original Milestone
Date
Current Status
Completion Date (if
applicable)
1 (Site
Wide)
VI Complete VI Screening
Investigations
PRP EPA 12/31/2014 Completed 5/23/2015
The preliminary results of the VI study from sampling completed in June 2014 were available for the 2014 Fourth FYR, but a second round completed in November 2014 was not available prior to completion of the 2014 FYR. A VI sampling and analysis report was completed and submitted to EPA on 4/23/2015. Based on an evaluation of multiple lines of evidence including groundwater quality data, soil vapor probe data, distance from the landfill and geologic conditions, it does not appear that a VI exposure risk attributable to the BFI landfill is present in the residential structures. In addition, an unacceptable vapor intrusion risk based on the groundwater quality data and EPA’s VI Screening calculator does not appear to exist at the former BFI Facility Managers residence and Hit or Miss Gun Club located east and southeast of the landfill.
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IV. FIVE-YEAR REVIEW PROCESS Community Notification, Involvement & Site Interviews A public notice was made available by EPA press release (https://www.epa.gov/newsreleases/epa-begins-reviews-six-vermont-superfund-site-cleanups-year) on the EPA website on 2/21/2019 and was covered by the Associated Press in newspapers and TV stations across the state of Vermont. The press release stated that there was a five-year review and invited the public to submit any comments to the EPA. The press release is included in Appendix F. The results of the review and the report will be posted to www.epa.gov/superfund/bfi and will be made available at the Site information repository located at: US Environmental Protection Agency, Region 1 5 Post Office Square, Suite 100 Boston, MA 02109-3912 During the FYR process, interviews were conducted with Mr. John Banholzer and Mr. Wayne Johnson, both longtime residents of Riverview Drive, which is downgradient of the landfill and serviced by the Missing Link Water System. Neither resident indicated any issues with the Site during the review period and both were aware of who to contact if issues arose. Mr. Johnson did indicate concerns with the drainage from Route 5 causing erosion to the drainage swales discharging to the Connecticut River. These issues appear to be related to the roadway drainage and not the Site. Interview summary sheets are included in Appendix G.
Data Review A long-term monitoring program has been ongoing at the Site to monitor the Site remedy for MNA since the ROD was signed in 1994. Environmental monitoring data are available for overburden and bedrock groundwater, shallow overburden groundwater collected by the Route 5 System groundwater collection trench, a surface seep (Seep SW-6) located along Route 5, the landfill cap tire chip drainage layer, Connecticut River surface water, and landfill leachate. The Fall 2018 Annual Monitoring Report (CES 2019b) presented a summary of data obtained from 2003 to 2018. Results from the more comprehensive Spring 2019 FYR annual sampling event are summarized in this Fifth FYR. Summary of the Spring 2019 5YR Monitoring Event Results The majority of the 2019 FYR annual sampling event was completed from April 14 – 19, 2019. It included the sampling of overburden and bedrock monitoring wells (9 overburden wells and 19 bedrock wells), the tire chip drainage layer, Seep SW-6, the Route 5 Shallow Groundwater Collection System (and AST), the lined ash monofill leachate collection system (consisting of an underground storage tank (UST)) and five water supply wells (the Missing Link Water Supply System primary and backup wells, the Hit or Miss Club well, and two residential wells). Sampling activities for the sampling event were designed to follow an EPA/VTDEC-approved Site-Specific Quality Assurance Project Plan (QAPP, CES 2019a). EPA performed a Technical Systems Assessment (TSA) of the sampling activities performed by TestAmerica on April 17, 2019 and found significant deviations from the procedures in the QAPP. These included observed deviations in procedures related to instrument calibration, sample collection, sample handling, calibration logs, sampling logs, and chain-of-custody forms during field sampling activities and EPA’s subsequent review of field documentation. EPA’s findings and recommendations are documented in a May 15, 2019 EPA memorandum titled, Technical Systems Assessment Report, Low-flow Groundwater Sampling and Storage Tank Sampling, Disposal Specialists, Inc. (DSI) Landfill Rockingham, Vermont, April 17, 2019. The results of the TSA were shared with the PRP and discussed with the PRP and its primary consultant so that potentially negative impacts from the deficiencies could be minimized, and recommendations adopted by the PRP
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and its agents. As a result of the findings, some of the data collected for the tire chip drainage layer, Route 5 System (AST), and the lined ash monofill leachate collection system underground storage tank (UST) during the April 2019 sampling event was qualified/rejected, and a second set of samples was collected in June 2019. The laboratory analyses were performed for selected metals, VOCs and SVOCs, consistent with the sampling and analysis plan utilized for previous FYR monitoring programs. In addition to the Five-Year Review monitoring requirements, 1,4-dioxane was added to the 2018 and 2019 analyte list and six per and polyfluorinated alkyl substances (PFAS) were analyzed at six monitoring wells and the Missing Link Water Supply Wells (primary and backup). ROD Contaminants of Concern The only contaminant of concern (COC) detected in eight offsite residential wells sampled during the 2015-2019 FYR period above the Interim Groundwater Cleanup Level (IGCL) was arsenic at 15.4 µg/L. Arsenic has historically been detected in seven of the eight offsite residential wells that are monitored on a rotating basis according to the LTMP. All residential wells are in areas of the Site that are not hydraulically downgradient of the landfill, and thus provide background levels for the area. COCs detected in the Missing Link Road Water Supply System above the IGCL during the 2015-2019 FYR period were arsenic, manganese, lead and 2-butanone. The system’s Primary Well #2 has been the sole source of water delivered to the residences along Riverview Drive. Lead and manganese have been detected in the Primary Well #2 sporadically over the past five-years, but only one exceedance has occurred in the post treatment water (lead at 15.5 µg/L in June 2015). Backup Well #3 has had detections of arsenic, lead and 2-butanone. While this well has not been used as a water supply well, it is regularly monitored along with Primary Well #2 in case it is temporarily needed. Water sourced from Primary Well #2 is filtered at the wellhead prior to distribution to the water supply system and residents. Backup Well #3 has an arsenic reduction system that treats groundwater sourced from it prior to distribution. Treated water from the Backup Well #3 was below the IGCL’s during the FYR period for the COCs except for a single exceedance of lead at 17.1 µg/L in October 2016. Backup Well #3 has had detections of 2-butanone sporadically over the five-year period, with one pretreatment sample exceeding the IGCL at 190 µg/L in April 2019 while the post-treatment sample was non-detect (ND) (less than 2.5 µg/L). Data from the Spring 2019 FYR sampling were summarized in Table 4, Appendix C, to present exceedances of the IGCLs in groundwater. Concentrations of certain COCs in samples from overburden and bedrock monitoring wells exceed one or more IGCLs established in the ROD for bedrock groundwater and/or the current State/Federal groundwater standards. The primary COCs observed in the Spring 2019 sampling event are manganese (15 of 28 wells) and arsenic (7 of 28 wells). VOC’s exceeding the IGCLs are only found in 3 of 28 wells and, of those, only one well is a bedrock well (MW-3). As previously noted, bedrock wells are the wells used to measure compliance with the ROD. VOCs detected above the IGCL in Spring 2019 were 2-butanone, methylene chloride and xylenes. Over the 5-year period (2015 –2019) concentrations of COCs barium, nickel, trichloroethane, tetrachloroethane, and vinyl chloride have only been above IGCLs intermittently in select wells. Only one of the four bedrock wells (MW-J38) sampled for SVOCs as part of the FYR had an exceedance of one SVOC (Bis (2-ethyl hexyl) phthalate) at a concentration slightly above its IGCL of 6 ug/l. It was also noted that the current detection limit for bis (2-chloroisopropyl) ether and pentachlorophenol is above the 1µg/L IGCL. The current detection limit for the compounds meets the requirement listed in the Remedial Action Statement of Work (SOW) contained in the Consent Decree (the SOW requires the detection limit to be below 5ug/L). However, because this detection limit does not allow for the detection of bis (2-chloroisopropyl) ether and pentachlorophenol down to the 1ug/L IGCL, a future modification to the SOW or related work plan may be necessary. A statistical analysis was performed to evaluate trends in COCs in groundwater that exceeded IGCLs in 2019. Statistical trends were evaluated using the non-parametric Mann-Kendall test which is only performed for
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parameters with more than five data points (i.e. detections above the laboratory reporting limit). Time series plots were visually interpreted to verify more recent trends in the data. The visual evaluation may be useful for situations where a contaminant statistically has no trend or is increasing but may have peaked and is presently declining over several years. A Mann-Kendall analysis utilizes the entire data set. It does not differentiate individual time periods. As a result, shorter periods of time may be visually interpreted to provide a complimentary tool to Mann-Kendall analysis. A summary of the 2019 well concentrations exceeding IGCL’s and the trend summary is included in Tables 5 (bedrock) and Table 6 (overburden) and visually shown in the trend charts contained in Appendix B. Overall, the VOCs and inorganics detected in overburden and bedrock wells in 2019 are consistent with historic results and trends. The overburden wells MW-E22 and MW-J35 continue to exceed IGCLs for VOCs, primarily 2- butanone, methylene chloride and total xylenes which show an overall increasing trend in the deep overburden. These VOCs (2-butonone, methylene chloride and total xylenes), as well as TCE and PCE, were previously detected at elevated concentrations in the upgradient shallow overburden well MW-B13D in the mid- to late-1990’s. MW-B13D is an onsite monitoring well located between the landfill and MW-J35. In the Conceptual Site Model Update (Summit 2012b), it was postulated that the delayed migration of VOCs to deeper overburden wells suggest that a “slug” of VOC-impacted groundwater has slowly migrated downward through the low permeability overburden deposits. However, significant or increasing levels of the VOCs have not been detected in bedrock. The VOCs in bedrock well MW-3 directly downgradient of MW-13D while present, do not appear to indicate a significant increasing trend of VOCs in bedrock groundwater. Methylene chloride has only been detected at this location twice over the past 10-years (2010 and 2019 at similar concentrations). The xylenes at this location have been stable or slightly increasing and although they are above the IGCL, are significantly below the EPA and VTDEC MCL. The trends in arsenic and manganese in groundwater wells are generally decreasing, with a few exceptions noted below. None of the bedrock or overburden wells exceeding the IGCL for arsenic had upward statistical or visual trends. Of the wells with manganese exceeding the IGCL, only three of nine bedrock wells and one of six overburden wells exhibited statistical increases in manganese and only four of nine bedrock wells and three of six overburden wells exhibited visual increases in manganese. The observed trends appear consistent with long-term trends used to estimate the additional 30-50 years required to achieve the cleanup identified in the ESD.
1,4-Dioxane and Per- and Polyfluoroalkyl Substances (PFAS) Monitoring Analysis of samples for 1,4-dioxane were completed for groundwater samples collected from six monitoring wells at the Site in November 2018 and April 2019. In addition, samples from the Missing Link Water Supply system were analyzed for the presence of 1,4-dioxane during the Spring 2019 sampling event. Analytical results for the November 2018 sampling event showed that 1,4-dioxane was detected in groundwater collected from each of the monitoring wells at concentrations that ranged from 0.37 µg/L in MW-B3, an upgradient deep bedrock monitoring well, to 280 µg/L in MW-J35, an overburden monitoring well located downgradient of the landfill that has historically been impacted by VOCs. Groundwater results above the risk-based screening level of 0.46 µg/L include 3.8 µg/L in MW-J37 and 29 µg/L in MW-7, both downgradient deep bedrock monitoring wells. Analytical results for the April 2019 sampling event detected 1,4-dioxane at concentrations ranging from non-detect (<0.2 ug/L) to 32,000 µg/L in MW-J35. Table 7, Appendix C presents a summary of the 2019 sampling results for 1,4 dioxane and PFAS. The limited 1,4-dioxane data set (two sampling events five months apart) and variations in detected concentrations between the two events does not allow an assessment of concentrations trends or seasonal fluctuations that additional sampling may provide.
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1,4-dioxane was not detected (detection limit of 0.2 ug/L) in samples from the Missing Link Water Supply System Primary and Backup supply wells during either the November 2018 or April 2019 sampling events. Analysis of samples for PFAS was completed in April 2019. Groundwater samples from the same six wells selected for 1,4-dioxane analysis were collected and analyzed for six PFAS compounds. Analytical results ranged from non-detect at five monitoring wells to 150 ng/L of Perfluoroctanoic Acid (PFOA) in MW-J35. The MW-J35 result exceeds both the recently promulgated (on July 6, 2019) Vermont Groundwater Protection Strategy and Rule standards of 20 nanograms per liter (ng/L) for groundwater for the combination of five (5) PFAS compounds (PFOA, Perfluorooctane sulfonic acid (PFOS), Perfluorohexanesulfonic acid (PFHxS), Perfluoroheptanoic acid (PFHpA), and Perfluorononanoic acid (PFNA)) and the EPA site-specific screening level and exposure assumption for a child resident of 40 ng/L for PFOA. PFAS was not detected (detection limit of 2 ng/L) in any of the Missing Link Water Supply System samples (Primary and Backup supply wells) collected during the April 2019 sampling event. Extent of Contamination The lateral extent of groundwater contamination in overburden and bedrock groundwater has not expanded since the last FYR and COCs are generally decreasing or remaining stable. As previously discussed, VOCs in two deeper overburden monitoring wells (MW-J35 and MW-E22) within the plume continue to show increasing trends which are attributed to the localized slow downward migration of impacted groundwater through silty clay overburden deposits (Summit 2012c; Summit 2014a). The lateral extent of VOCs in bedrock groundwater is limited to a narrow zone between MW-6 and MW-9, while the lateral extent of VOCs in overburden groundwater occurs in a slightly wider zone between B-7and the seep location SW-6. Chromium and barium exceedances in groundwater monitoring wells have been sporadically observed in isolated areas around MW-B13D and MW-9 respectively. VOCs, chromium and barium are interpreted to be the result of migration of these constituents from the landfill. Concentrations of manganese and arsenic that exceed the IGCL occur in areas located closest to and downgradient of the landfill; however, note that arsenic concentrations above the IGCL have also been reported at multiple background residential water supply wells (i.e. reference wells) located in the area of the Site; which are routinely sampled as part of long-term monitoring activities. The presence of manganese and arsenic in groundwater affected by the landfill is most likely the result of a reducing environment attributable to the landfill that has mobilized naturally-occurring arsenic and manganese, as opposed to a migrating plume of arsenic and manganese from the landfill.
Site Inspection The inspection of the Site was conducted on June 12, 2019. In attendance were Kevin Heine, U.S. EPA; Chris Ford, BFI-VT; Roger Bellerose, BGEC, LLC (Site maintenance contractor); and Michael Deyling, CES Inc., (environmental consultant and reporting contractor). The purpose of the inspection was to visually assess the protectiveness of the remedy. The site inspection included a systematic traverse of the landfill to evaluate general site conditions (fencing, signage, natural barriers, access roads), monitoring well security, landfill gas management system, and landfill cover system (vegetation, settlement, drainage, vectors) and associated components (stormwater management structures). Site inspections have been performed by BFI-VT, EPA (or their oversight contactor), and VTANR since 1999. Consistent with previous inspection results, no major issues regarding the operation and maintenance of the landfill remedial systems were noted. Remedial measures and Institutional Controls remain operational and effective at the Site. An inspection checklist is included in Appendix H.
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V. TECHNICAL ASSESSMENT QUESTION A: Is the remedy functioning as intended by the decision documents?
Remedial Action Performance Yes. Remedial actions continue to operate and function as designed as evidenced by the following:
The multilayer landfill cap remains intact to isolate and prevent direct contact with the solid waste
contained in the landfill. The solid waste mass and cap appears to be intact and stable against slope movement at this time. The
June 12, 2019 inspection did not identify changes in cap conditions or the presence of settlement features.
A reduction in the groundwater elevations near the landfill and the decline in leachate collection system flow volumes are both indicators that the landfill cap has minimized the infiltration of surface water through the solid waste mass.
Long-term improvements in the quality of shallow groundwater intercepted by the Route 5 System are also indicative of a decline in contaminants present in shallow overburden groundwater intercepted by the trench.
The lack of new seeps at the Site and the intermittent flow of Seep SW-6 indicate that the landfill cap and the Route 5 System (groundwater interceptor trench) are effectively reducing the flow of contaminated shallow groundwater that could develop into seeps and potentially impact surface water.
The landfill gas management system has controlled landfill gas emissions, so methane gas does not represent an explosion hazard, and prevented the release and subsequent exposure (inhalation) of landfill gas potentially containing hazardous substances, pollutants or contaminants. Installation of a candlestick flare has increased the operational time of the gas treatment system which is an improvement over the previous flare which was working intermittently because it required more gas flow.
The private water supply system (Missing Link Water Supply) serving four residents on Riverfront Drive continues to function efficiently and continues to meet State and Federal water quality standards.
There has been no indication that contaminated groundwater is spreading outside the Groundwater Reclassification Zone. As indicated in Annual Monitoring Reports, contaminant concentration trends in groundwater are generally stable or decreasing.
System Operations/O&M Operation and maintenance of the landfill cap, drinking water supply system, gas management system
and leachate and shallow groundwater seepage have followed standard operating procedures, and continue to maintain the effectiveness of site remediation.
In 2018, SCS Field Services (SCSFS), the gas management consultant for BFI proposed decommissioning several gas extraction wells that were ineffective in extracting landfill gas. According to SCSFS, the removal of these points will not impact the capture of the gas collection system which can be handled by the remaining gas extraction wells. Decommissioning is planned for September 2019.
Opportunities for Optimization
The control systems, instrumentation and treatment components for the Missing Link Water System (filters, arsenic removal cannisters) are being relocated from the former Manager’s
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residence to a newly constructed building adjacent to the landfill. The relocation provides greater security, as well as better access for maintenance and monitoring.
Early Indicators of Potential Issues
There are no indicators of imminent failure or issues with the site remedies. Inspections of the landfill cap noted slight depressions from settling in 2012 (which are considered typical for a closed landfill), but these areas are stable with no noticeable change in extent. Monitoring of the areas continues quarterly for evidence of ponding of water or instability.
Implementation of Institutional Controls and Other Measures
As noted in the latest 2018 Annual Inspection and the 2019 FYR Site Inspection, access controls (e.g., fencing and warning signs) are in place and effective in preventing unauthorized entry to the Site.
The institutional controls to prevent installation of new drinking water wells in the Groundwater Reclassification Zone are in place and have been effective in preventing exposure to contaminated groundwater
Financial Assurance instruments are in place for the Site. There are no known immediate threats that require removal or additional remediation.
QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives used at the time of the remedy section still valid? Question B Summary: No. There have been changes in exposure assumptions, risk assessment methods, and toxicity values since the time of remedy selection; however, the RAOs are still valid. The changes as described below are not expected to alter the protectiveness of the remedy because a private water line serves downgradient households and the multilayer landfill cover remains intact. Additionally, ICs are in place which prevent installation of new drinking water wells and prohibit use of groundwater at the Site.
Changes in Standards and TBCs
Changes to the IGCLs from the 1994 ROD were made in the 2014 ESD for arsenic (10µg/L) and lead
(15µg/L) to match current Federal and VTDEC MCLs. The evaluation of the potential exposure pathway by vapor intrusion was investigated in 2014 and
reported in 2015 and as previously noted is not considered an exposure pathway at the Site. All other assumptions of exposure pathways are still valid and have been addressed.
The RAOs have been addressed and remain valid for the site. The following paragraph(s) discuss only those federal or state statutes or regulations (including any newly promulgated standards) or TBCs that may have changed since the 2014 ESD and that may be applicable to the Site: Vermont Groundwater Protection Rule and Strategy: VTANR promulgated revised Groundwater Protection Rule and Strategy on July 6, 2019 (Chapter 12 of the Environmental Protection Rules) which include revisions to the VGES. O&M monitoring reports include comparison to the revised VGES, although EPA has not made a determination as to whether these new standards will be adopted for this Site. Additional investigation is needed to determine if identified exceedances of revised VGES standards are Site-related. The revised rules may be considered in any future CERCLA decision document if it is determined that exceedances of the standards are site-related. As there is no current use of groundwater on the Site and a private water line and ICs are in place preventing exposure to Site-impacted groundwater, changes to VGES do not affect the short-term protectiveness
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of the remedy on-site. Changes in Toxicity and Other Contaminant Characteristics
Since the previous FYR, there have not been any changes in the toxicity of contaminants of concern. However, 1,4-dioxane and PFAS compounds have been added to Site monitoring. Additionally, EPA issued an updated policy on addressing lead in soil. These changes would not be expected to alter the protectiveness of the remedy because the multilayer landfill cover remains intact and ICs are in place preventing exposure to Site-impacted groundwater and landfill wastes. Additionally, the nature and extent of contaminants with concentrations over the IGCLs is generally remaining stable or declining.
2013 1,4-dioxane cancer and non-cancer toxicity values
In 2013, EPA revised the toxicity values for 1,4-dioxane. The oral slope factor increased, while the value for inhalation unit risk decreased, which indicates that 1,4-dioxane is more toxic from cancer health effects via the oral pathway, but less toxic from inhalation. Additionally, the non-cancer values for oral reference dose and inhalation reference concentration both decreased, which indicates that 1,4-dioxane is more toxic from non-cancer hazards. 1,4-dioxane was included in the list of target analytes for both Fall 2018 Semi-annual and Spring 2019 FYR groundwater sampling events. The fall 2018 data showed that 1,4-dioxane was detected in groundwater collected from each of the five MWs at concentrations that ranged from 0.37 µg/L to 280 µg/L. Concentration detected in the Spring 2019 sampling event ranged from ND (< 0.2 ug/L) to 32,000 µg/L. Detections of 1,4-dioxane do not call into question the current protectiveness of the remedy because a private water line and ICs are in place preventing exposure to Site-impacted groundwater. Water supply samples did not detect the presence of 1,4-dioxane during the Fall 2018 or Spring 2019 sampling events. Leachate collected onsite should be analyzed for 1,4-dioxane prior to offsite disposal.
2017 Polycyclic Aromatic Hydrocarbons (PAHs)
On January 19, 2017, EPA issued revised cancer toxicity values and new non-cancer toxicity values for benzo(a)pyrene. Benzo(a)pyrene did not have non-cancer toxicity values prior to January 19, 2017. Benzo(a)pyrene is now considered to be carcinogenic by a mutagenic mode of action; therefore, cancer risks must be evaluated for different human developmental stages using age dependent potency adjustment factors for different age groups. The cancer potency of other carcinogenic PAHs is adjusted using relative potency factors, which are expressed relative to the potency of benzo(a)pyrene. PAHs are among the COCs for pond and seep sediments in the ROD. Sediments did not contribute to an unacceptable risk at the Site and therefore, clean-up levels for PAHs were not calculated. Changes to toxicity may result in a re-evaluation of Site risks. There is no current exposure to Site sediments that would affect the protectiveness of the remedy.
2016 PFOA/PFOS non-cancer toxicity values
On May 19, 2016, EPA issued final lifetime drinking water health advisories for PFOA and PFOS, which identified a chronic oral RfD of 2E-05 mg/kg-day for PFOA and PFOS (EPA, 2016a and EPA, 2016b). These RfD values should be used when evaluating potential risks from ingestion of contaminated groundwater at Superfund sites where PFOA and PFOS might be present, based on site history. Potential estimated health risks from PFOA and PFOS, if identified, would likely increase total site risks due to groundwater exposure. Further evaluation of potential risks from exposure to PFOA and PFOS in other media at the Site might be needed based on site conditions and may also affect total site risks.
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2014 Perfluorobutanesulfonic Acid (PFBS) non-cancer toxicity value
PFBS has a chronic oral RfD of 2E-02 mg/kg-day based on an EPA Provisional Peer Reviewed Toxicity Value (PPRTV) (USEPA, 2014a). This RfD value should be used when evaluating potential risks from ingestion of contaminated groundwater at Superfund sites where PFBS might be present based on site history. Potential estimated health risks from PFBS, if identified, would likely increase total site risks due to groundwater exposure. Further evaluation of potential risks from exposure to PFBS in other media at the Site might be needed based on site conditions and can also affect total site risks. PFOA, PFOS, and PFBS belong to a group of compounds known as PFAS, which have been used in a variety of industrial applications and can be associated with Sites that have a history of industrial/chemical waste disposal. Based on the Site history as a landfill, PFAS compounds were added to groundwater monitoring for Spring 2019. Groundwater samples from the same six wells selected for 1,4-dioxane analysis were collected and analyzed for six PFAS compounds. Analytical results ranged from ND (detection limit of 1.8 ng/L) in 3 samples to 150 ng/L for PFOA in one overburden groundwater sample, which exceeded the risk-based groundwater screening level. Detections of PFAS do not call into question the current protectiveness of the remedy because a private water line and ICs are in place preventing exposure to Site-impacted groundwater. Leachate collected onsite should be analyzed for PFAS prior to offsite disposal. PFAS was not detected (detection limit of 2 ng/L) in any of the Missing Link Water Supply System samples (Primary and Backup supply wells) in the April 2019 samples.
2016 Lead in Soil Cleanups EPA’s 2016 OLEM memorandum "Updated Scientific Considerations for Lead in Soil Cleanups" (OLEM Directive 9200.2-167) indicates that adverse health effects are associated with blood lead levels (BLLs) at less than 10 µg/dL. The memo mentioned that several studies have observed “clear evidence of cognitive function decrements in young children with mean or group BLLs between 2 and 8 μg/dL.” Any soil screening, action or cleanup level developed based on the previous target BLL of 10 μg/dL may not be protective.
EPA’s approach to evaluate potential lead risks is to limit exposure to residential and commercial soil lead levels such that a typical (or hypothetical) child or group of similarly exposed children would have an estimated risk of no more than 5% of the population exceeding a 5 µg/dL blood lead level (BLL). This is based on evidence indicating cognitive impacts at BLLs below 10 µg/dL. Additionally, this approach aligns with the Lead Technical Review Workgroup’s current support for using a BLL of 5 µg/dL as the level of concern in the Integrated Exposure Uptake Biokinetic Model (IEUBK) and Adult Lead Methodology (ALM). A target BLL of 5 µg/dL reflects current scientific literature on lead toxicology and epidemiology that provides evidence that the adverse health effects of lead exposure do not have a threshold.
EPA’s 2017 OLEM memorandum “Transmittal of Update to the Adult Lead Methodology’s Default Baseline Blood Lead Concentration and Geometric Standard Deviation Parameters” (OLEM Directive 9285.6-56) provides updates on the default baseline blood lead concentration and default geometric standard deviation input parameters for the Adult Lead Methodology. These updates are based on the analysis of the NHANES 2009-2014 data, with recommended updated values for baseline blood lead concentration being 0.6 µg/dL and geometric standard deviation being 1.8.
Using updated default IEUBK and ALM parameters at a target BLL of 5 µg/dL, site-specific lead soil screening levels (SLs) of 200 ppm and 1,000 ppm are developed for residential and commercial/industrial exposures, respectively.
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Risks from soil exposures were not evaluated for BFI Rockingham since the remedy included a landfill cap. The multilayer landfill cover remains intact and prevents exposure to soil contaminants related to landfilling operations, therefore this updated EPA policy does not indicate any unacceptable risks from lead in soil for this Site. Changes in Risk Assessment Methods
2014 Office of Solid Waste and Emergency Response (OSWER) Directive Determining Groundwater Exposure Point Concentrations, Supplemental Guidance
In 2014, EPA finalized a Directive to determine groundwater Exposure Point Concentrations (EPCs) https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=236917. This Directive provides recommendations to develop groundwater EPCs. The recommendations to calculate the 95% Upper Confidence Level (UCL) of the arithmetic mean concentration for each contaminant from wells within the core/center of the plume, using the statistical software ProUCL could result in lower groundwater EPCs than the maximum concentrations routinely used for EPCs as past practice in risk assessment, leading to changes in groundwater risk screening and evaluation. In general, this approach could result in slightly lower risk or lower screening levels. This change does not impact the protectiveness of the remedy. (Reference: USEPA. 2014. Determining Groundwater Exposure Point Concentrations. OSWER Directive 9283.1-42. February 2014.) Changes in Exposure Pathways
No new ecological routes of exposure or receptors have been identified since the previous FYR. Exposure to VOCs through vapor intrusion (VI) was not evaluated during the original risk assessment, however, was identified as a potential exposure pathway during the 2014 FYR. As a result, VI was evaluated during this FYR period as described below. Land use and expected land use in the area around the site remains unchanged with rural residential land use. Additionally, there are no observed changes to physical site conditions that could affect the protectiveness of the remedy. Continued reduction in groundwater levels from reduced infiltration through the cap have reduced or eliminated offsite seeps. Volumes of shallow groundwater seepage collected along Route 5 and at Seep -6 and reduction of groundwater levels at shallow overburden wells (MW-13D) are indicators of the effectiveness of the cap. 2014 OSWER Directive on the Update of Standard Default Exposure Factors
In 2014, EPA finalized a Directive to update standard default exposure factors and frequently asked questions associated with these updates. https://www.epa.gov/sites/production/files/2015-11/documents/oswer_directive_9200.1-120_exposurefactors_corrected2.pdf. Many of these exposure factors differ from those used in the risk assessments supporting the ROD. These changes in general would result in a slight decrease of the risk estimates for most chemicals (EPA, 2014b). These changes do not currently affect the remedy because residents are provided an alternate water supply and ICs are in place. In February 2018, EPA launched an online Vapor Intrusion Screening Level (VISL) calculator which can be used to obtain risk-based screening level concentrations for groundwater, sub-slab soil gas, and indoor air. The VISL calculator uses the same database as the Regional Screening Levels (RSL) for toxicity values and physiochemical parameters and is automatically updated during the semi-annual RSL updates. The User’s Guide provides further details on how to use the VISL calculator. https://www.epa.gov/vaporintrusion/vapor-intrusion-screening-level-calculator . Potential vapor intrusion of VOCs into buildings was not included as a potential exposure pathway in the ROD, however this pathway was identified prior to the 2014 FYR as requiring further investigation. Soil vapor and
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groundwater data were collected and evaluated for potential VI risks in 2014. The VI evaluation for groundwater and soil vapor showed that the maximum detected concentrations of VOCs were either within EPA’s acceptable risk range of 10⁻⁴ to 10⁻⁶ or at/below the acceptable non-cancer hazard quotient level of 1. Based on the current data, there are no unacceptable risks from VI, however, if there is a change in site conditions this pathway may need to be re-evaluated. Expected Progress Towards Meeting RAOs The Site remedy continues to be effective in meeting the goals of the RAO although the timeframe to meet the goals were adjusted as documented in the 2014 ESD. Arsenic and manganese are the principle constituents of concern requiring an extended period of time to restore bedrock groundwater to IGCLs (2050 to 2070). The VOCs concentrations at bedrock compliance wells have decreased to concentrations at or approaching the IGCLs, such that they are no longer considered to be a driving factor for predicting the timeframe for the restoration of bedrock groundwater quality at the Site and VOC IGCLs are expected to be achieved in bedrock groundwater by 2025. A vapor intrusion investigation for the Site completed in 2015 did not indicate that vapor intrusion was a pathway of concern. Overall no changes to remedial; actions, contaminant concentrations, pathways, or toxicity have come to light that affect the current protectiveness of the remedies employed. No new contaminant sources have been identified since startup of the remedy. In response to area-wide 1,4-dioxane and PFAS concerns, analysis of site groundwater for both has been conducted. 1,4-dioxane was detected in multiple downgradient monitoring wells at levels exceeding the EPA risk-based screening level of 0.46 µg/L. Total PFAS concentrations exceeded both the recently promulgated Vermont drinking water standard of 20 ng/L in one monitoring well on the site as well as the risk-based screening level of 40 ng/L (specific to PFOA and PFAS). However, there are no current users of groundwater on-site and ICs prevent future use of groundwater and analysis of the primary and backup water supply system wells was non-detect for 1,4-dioxane and PFAS. Additional assessment of both compounds is needed onsite, as is the addition of both 1,4-dioxane and PFAS to the monitoring analyte list for the water supply wells.
QUESTION C: Has any other information come to light that could call into question the protectiveness of the remedy? No.
VI. ISSUES/RECOMMENDATIONS
Issues/Recommendations
OU(s) without Issues/Recommendations Identified in the Five-Year Review:
None.
Issues and Recommendations Identified in the Five-Year Review:
OU(s): 1 Issue Category: Monitoring.
Issue: 1,4-dioxane and PFAS were detected in groundwater monitoring samples collected from the Site.
Recommendation: Revise the LTMP to include routine monitoring for 1,4-dioxane and PFAS, including 1,4-dioxane and PFAS sampling of the primary and backup drinking water supply wells for the Missing Link Road Water Supply System, and 1,4-dioxane and PFAS sampling of leachate.
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Affect Current Protectiveness
Affect Future Protectiveness
Party Responsible
Oversight Party Milestone Date
No Yes PRP EPA 3/31/2020
OTHER FINDINGS In addition, the following recommendations were identified during the FYR and should improve management of Site O&M, but do not affect current and/or future protectiveness:
Issues with sampling protocols for groundwater low flow sampling and use of sampling equipment for sample collection were identified as deviations from the QAPP during an audit of the Spring 2019 sampling event. All calibration standards, protocols, methods, and standard operating procedures, etc. identified in the Site-specific QAPP need to be followed. As a signatory to the QAPP, the RP and its agents/contractors assure the proper implementation of the QAPP. The RP should review the performance of its agents/contractors and make appropriate changes to ensure all personnel are properly trained and familiar with the QAPP so that it is properly followed.
Continue to monitor existing institutional controls and foster positive relations with local residents to help ensure groundwater use remains restrictive at the Site.
VII. PROTECTIVENESS STATEMENT
Sitewide Protectiveness Statement
Operable Unit: 1 (Site Wide)
Protectiveness Determination: Short-term Protective
Protectiveness Statement: The remedy currently protects human health and the environment because there is no current exposure of Site related contaminants to humans or the environment at concentrations that would represent an unacceptable risk. Existing protective measures and conditions at the Site, including the landfill cap, the landfill gas collection system, the private water supply system, and ICs, coupled with continued maintenance activities and regular oversight inspections and monitoring, help ensure that the remedy remains effective and protective of human health and the environment. However, in order to be protective in the long-term, the LTMP must be revised to include routine monitoring for 1,4-dioxane and PFAS, including in samples collected from the primary and backup drinking water supply wells for the Missing Link Road Water Supply System, and from leachate.
VIII. NEXT REVIEW The next five-year review report for the BFI Rockingham Landfill Superfund Site is required five years from the completion date of this review.
APPENDIX A – REFERENCE LIST
Balsam Environmental Consultants, Inc., 1994. “Feasibility Study Disposal Specialists, Inc. Site Rockingham, Vermont”. CES, Inc. 2014a, 2014 Vapor Intrusion Investigation Summary Report, Disposal Specialists, Inc. Landfill, Rockingham, Vermont. April 2014 CES, Inc. 2014b, Spring 2014 Five Year Review Semi-Annual Monitoring Report, Disposal Specialists, Inc. Landfill, Rockingham Vermont. June 2014 CES, Inc. 2014c, Fall 2014 Five Year Review Semi-Annual Monitoring Report, Disposal Specialists, Inc. Landfill, Rockingham Vermont. October 2014. CES, Inc. 2015a, Proposed 2015-2018 Long Term Monitoring Plan Revision, Disposal Specialists, Inc. Landfill, Rockingham, Vermont. April 2015 CES, Inc. 2015b, Vapor Intrusion Investigation Summary Report, Disposal Specialists, Inc. Landfill, Rockingham, Vermont. August 2015 CES, Inc. 2015c Spring 2015 Semi-Annual Monitoring Report, Disposal Specialists, Inc. Landfill, Rockingham, Vermont. September 2015 CES, Inc. 2016 Annual Monitoring Report, Disposal Specialists, Inc. Landfill, Rockingham, Vermont. May 2017 CES, Inc. 2017 Annual Monitoring Report, Disposal Specialists, Inc. Landfill, Rockingham, Vermont. May 2018 CES, Inc. 2018 Annual Monitoring Report, Disposal Specialists, Inc. Landfill, Rockingham, Vermont. April 2019 CES, Inc. 2019 2019 Five Year Review Quality Assurance Project Plan (QAPP), DSI Inc. Landfill, Rockingham, Vermont. April 2019 Dames & Moore, Inc., 1994. “Demonstration of Compliance Plan Non-Time Critical Removal Action for the Disposal Specialists, Inc. Landfill, Rockingham, Vermont”. Dames & Moore, Inc., 1997. “Long-Term Monitoring Plan, Disposal Specialists, Inc. Site, Rockingham, Vermont”. Jurgens, B.C., McMahon, P.B., Chapelle, F.H., and Eberts, S.M. (2009), “An Excel® Workbook for Identifying Redox Processes in Ground Water”: U.S. Geological Survey Open-File Report 2009–1004 Summit Environmental Consultants, Inc., 2009. “Field Investigation Work Plan Supporting Technical Impracticability Evaluation, DSI Landfill, Rockingham, Vermont. Summit Environmental Consultants, Inc., 2012a. “Investigation Plan, DSI Rockingham Landfill, Rockingham, Vermont”, January 12, 2012. Summit Environmental Consultants, Inc., 2012b. “Conceptual Site Model Update, Disposal Specialist Inc. Landfill, Rockingham, Vermont”, August 2012.
Summit Environmental Consultants, Inc., 2012c. “Vapor Intrusion Evaluation, Disposal Specialist Inc. Landfill, Rockingham, Vermont”, August 2012. Summit Environmental Consultants, Inc., 2012d. “Spring 2012 Semi-Annual Monitoring Report, Disposal Specialist Inc. Landfill, Rockingham, Vermont”, October 2012. Summit Environmental Consultants, Inc., 2013a. “Fall 2012 Semi-Annual Monitoring Report, Disposal Specialist Inc. Landfill, Rockingham, Vermont”, February 2013. Summit Environmental Consultants, Inc., 2013b. “Residential Water Supply System and Missing Link Road Non-Public Water Supply System Operations and Maintenance Manual, DSI Rockingham Landfill, Rockingham, Vermont”, June 7, 2013. Summit Environmental Consultants, Inc., 2013c. “Spring 2013 Semi-Annual Monitoring Report, Disposal Specialist Inc. Landfill, Rockingham, Vermont”, October 2013. Summit Environmental Consultants, 2014. 2014 Five Year Review Quality Assurance Project Plan (QAPP), Disposal Specialist, Inc. Landfill, Rockingham, Vermont. April 2014. Summit Environmental Consultants, 2014b. “Draft Additional Investigations Plan Summary Report and Estimated Timeframe for the Restoration of Bedrock Groundwater, BFI Sanitary Landfill Superfund Site - Disposal Specialists, Inc. Landfill, Missing Link Road (Route 5), Rockingham, Vermont”, July 23, 2014. Summit Environmental Consultants, Inc., 2015a. “Spring 2015 Semi-Annual Monitoring Report, Disposal Specialist Inc. Landfill, Rockingham, Vermont”, August 2015. Summit Environmental Consultants, Inc., 2015b. “Fall 2015 Semi-Annual Monitoring Report, Disposal Specialist Inc. Landfill, Rockingham, Vermont”, March 2016. United States of America and State of Vermont, 1996. “Consent Decree” and Statement of Work. USEPA 2014. “Explanation of Significant Differences, BFI Rockingham Landfill Superfund Site, Rockingham Vermont”. September 29, 2014. URS Corporation, 2009. “Fall 2008 Semi-Annual Monitoring Report, Disposal Specialists, Inc. Site, Rockingham, Vermont”. VTANR, 2013. “Findings of Fact & Reclassification Order Amendment to the Groundwater Reclassification at the DSI Landfill Rockingham Vermont”, prepared by The Vermont Agency of Natural Resources, dated November 4, 2013 and executed November 6, 2013.
APPENDIX B – FIGURES
SITE
SOURCE:
U.S.G.S. TOPOGRAPHIC QUADRANGLE
Terrain N
avigator,©
M
aptech 800-627-7236
DISPOSAL SPECIALIST, INC. LANDFILL
MISSING LINK RD (RTE 5) - ROCKINGHAM, VT
9/17/2014
16819
BELLOWS FALLS
@ 1:24,000 = 1" = 2,000'
FIGURE 1
LOCATION MAP
L
IN
E
C
R
O
S
S
S
E
C
T
IO
N
LIN
E
C
R
O
S
S
S
E
C
T
IO
N
A'
A
B
B'
BEDROCK
OUTCROP
AREA
4-107-014
PARCEL
4-107-012
(BANHOLZER)
A
P
P
R
O
X
IM
A
T
E
R
.O
.W
.
WELL #2
GREENWOOD RESIDENCE AND
FACILITY MAINTENANCE BUILDING
4-505-894
LEACH
FIELD
WELL #3
MISSING LINK ROAD
WATER SUPPLY
4-505-890
PARCEL
WELL #1
(ABANDONED)
PARCEL
4-505-897
HIT OR MISS
CLUB WELL
L
IM
IT
O
F
S
O
L
ID
W
A
S
T
E
POND
BUILDING
BLOWER
C
C
ELECTRIC
20,000 GALLON AST
C
C
BOX
FM
C
FM
C
PARCEL
A
P
P
R
O
X
I
M
A
T
E
R
.
O
.
W
.
PARCEL
4-107-032
F
M
ROUTE 5 SLOPE STABILIZATION AND
SEEPAGE CONTROL SYSTEM
FM
FM
C
C
FM
C
DANFORTH
WELL
C
CRAIGUE
WELL
PARCEL
RUMRILL
SPRING
A
R
E
A
N
O
T
S
U
R
V
E
Y
E
D
PARCEL
4-107-006
PARCEL
4-505-949
(RUMRILL)
PARCEL
4-107-010
(JOHNSON)
(GLYNN/STRICKLAND)
C
U
L
V
E
R
T
CULVERT
ROUTE 5 SLOPE STABILIZATION AND
SEEPAGE CONTROL SYSTEM
20,000 GALLON ABOVE GROUND
STORAGE TANK
FIGURE 2
MIS
SIN
G L
IN
K R
OA
D - R
OC
KIN
GH
AM
, V
T
20
19
-0
1-2
9
16
81
9
BL
Q
DB
SC
AL
E:
DA
TE
:
JO
B N
O.:
DR
AW
N B
Y:
CH
EC
KE
D B
Y:
64
0 M
AIN
S
TR
EE
T
LE
WIS
TO
N, M
E 0
42
40
Te
l.: (2
07
) 7
95
-6
00
9
Fa
x: (2
07
) 7
95
-6
12
8
WW
W.C
ES
-M
AIN
E.C
OM
V
V
V
V
00 200' 400'
DIS
PO
SA
L S
PE
CIA
LIS
T, IN
C. L
AN
DF
IL
L
SIT
E P
LA
N
LEGEND
LANDFILL SOLID WASTE BOUNDARY
MONITORING WELL
MONITORING WELL ANNUAL SAMPLING
GAS EXTRACTION WELL
FORMER WATER SUPPLY WELL (NOT IN USE)
NOTES
W
CT RIVER OR SEEP SAMPLING LOCATION
MISSING LINK ROAD NON-PUBLIC WATER
SYSTEM WATER SUPPLY LINE
SOIL VAPOR PROBE
V
1. RESIDENTIAL WELLS SAMPLED DURING LONG-TERM MONITORING ACTIVITIES
ARE NOT SHOWN ON THIS SITE PLAN.
2. STORMWATER CULVERTS EAST OF ROUTE 5 WERE LOCATED APPROXIMATELY
USING HISTORICAL FIGURES.
3. SOIL VAPOR PROBES ARE SHOWN IN APPROXIMATE LOCATIONS.
AN
NU
AL
S
AM
PL
IN
G
- ---0 VP-1
♦MW-6 ♦MW-9 0 EW 11A
-$- RW-4
A
-
,, /
--$-RW2
/ -/ ---
1 /
\ \
! r I
I
--$-RW3
RJV£R
\ \
\
K-40 -y ,,, ,,,
--$-RW4
DISPOSAL SPECIALISTS, INC. LANDFILL
MISSING LINK RD (ROUTE 5) - ROCKINGHAM, VERMONT
GEOLOGICAL CROSS SEECTION A-A'
FIGURE 310338.029
AS NOTED
SBM/JNB
2019-07-03
MAD
PROJ:CT TITLE:
SHEET TITLE:
GREENWOOD WELL
• W-E22 W-C15 INTERSECTION e-e· W-A12
/J
W-E21 /JW-C16 rW-A11
W-E23 W-C17 I W-E24 W-C18 f
@------L..------~•-···••--------11■1■1f--------__,__---,r--,------------------<-.. ---------1® MW-B13t/_,J,.~:
500
_J
~ 450 w _J
<( w Ul 400 z <( w 2
w 350 > 0 m <(
~ 300 w LL
~
z 250 0 F <( > ~ 200 w
U.S. ROUTE 5
H E--'-::'..:_'.C:: ~__::__--=c:.~-=-::_='..c_~__:=--=_;_c-~--~~. ;.' c~:,-~-~ c.•~~L . F · :_ : --=-- - - _-_- - : - - - : - -____:_ ----- ·- ------ - --r~...; _:_._ - . - - - ·- · - - - - ·- - ·----- ·- ·---·
r~_ - _ ---:-......:....__ · _ - _ · _ __:__ -· _ ---:-__:____-r- -- -- --- - - ---- - - - --L---:-___:__ . _:_--:-____:_ · --:- ....:..._---:-· - - - . _:_--:-
GREENWOOD (OPEN HOLE)
MW-E22
MW-E24
MW-B13D \ MW-814 W-2 \ ~:=l LIMIT OF SOLID WASlE--------
W-3
500
450
400
350
300
250
200
150~--~ --~ - ~-- ~ --~ --~ - -~- ~ --~ --~ --~ - ~ - - ~ --~ --~ --~ - ~ - - ~ --~ --~ --~-+-- 150 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
DISTANCE ( FEET)
DWG: BY: REV: DESCRIPTION:
DATE· REV DATE:
J>J: APPROVED BY: ISSUE: DESCRIPTION:
SCALE: CHECKED BY: ISSUE DATE:
SOURCE: BALSAM ENVIRONMENTAL CONSULTANTS, FROM A PLAN ENTITLED "CONCENTRATION DISTRIBUTION OF TOTAL IRON IN GROUND WATIER, CROSS SECTION 1-1"', DATED 4/18/94.
NOTES:
1) CONCEPTUALIZED STRATIGRAPHY BASED ON UMITIED SUBSURFACE DATA COLLECTED FROM BORINGS ADVANCED FROM 1977 THROUGH 1992. IN ADDITION, SEVERAL PRIVATIE RESIDENTIAL WELL LOGS WERE INCLUDED.
2) SURFACE ELEVATION OF REFUSE REFLECTS CONDITIONS PRIOR TO REGRADE AND CAPPING.
100
LEGEND ~ REFUSE
r·,. ::<: _:·:_.:J SAND
~--_--'---~---1. SILT WITH SAND c- - --;:J (VARVED LACUSTRINE)
-~~ I
CLAYEY SILT (VARVED LACUSTRINE)
ROCK FRAGMENTS AND SILT (BASAL TILL)
BEDROCK
SCREENED INlERVAL
PROJECTED MONITORING WELL DISTANCE ~ 50 FEET FROM CROSS SECTION LINE
0 '50 100
1" = 100' VERT
0 100 200
1" = 200' H0RZ
CES1NC El"ljineers • Environmontal Sciontisbl • Su,wyors
200
400
DISPOSAL SPECIALISTS, INC. LANDFILL
MISSING LINK RD (ROUTE 5) - ROCKINGHAM, VERMONT
GEOLOGICAL CROSS SEECTION B-B'
FIGURE 410338.029
AS NOTED
SBM/JNB
2019-07-03
MAD
~
II: 111 Lll:i.llP' I lie
::.': ( !;PS)tl 1-01,,Q
:,
""' ~ 40.:-
0 00 IJUl
o .. ""CE
PROJ:CT TITLE: DWG: BY: REV: DESCRIPTION:
DATE· REV DATE:
SHEET TITLE: J,J: APPROVED BY: ISSUE: DESCRIPTION:
SCALE: CHECKED BY: ISSUE DATE:
SOURCE: BALSAM ENVIRONMENTAL CONSULTANTS, FROM A PLAN ENTITLED "CONCENTRATION DISTRIBUTION OF TOTAL IRON IN GROUND WATER, CROSS SECTION 1-1"', DATED 4/18/94.
NOTES:
1) CONCEPTUALIZED STRATIGRAPHY BASED ON LIMITED SUBSURFACE DATA COLLECTED FROM BORINGS ADVANCED FROM 1977 THROUGH 1992. IN ADDITION, SEVERAL PRIVATE RESIDENTIAL WELL LOGS WERE INCLUDED.
2) SURFACE ELEVATION OF REFUSE REFLECTS CONDITIONS PRIOR TO REGRADE AND CAPPING.
§. -_-'- - -~~. ·- :--·-
-~~? .:~ '
~.!
100
LEGEND REFUSE
SAND
SILT WITH SAND (VARVED LACUSTRINE)
~, A.YEY SILT RVED LACUSTRINE)
:K FRAGMENTS AND r (BASAL TILL)
IROCK
!EENED INTERVAL
PROJECTED MONITORING WELL DISTANCE ~ 50 FEET FROM CROSS SECTION LINE
0 '50 100
1'" = 100' VERT
0 100 200
1" = 200' H0RZ
CES1NC Erljineers • Environmontal Sciontisbl • SUJWY011
200
400
Engineers Environmental Scientists Surveyors
DISPOSAL SPECIALISTS, INC. LANDFILL
MISSING LINK RD (ROUTE 5) - ROCKINGHAM, VERMONT
SHALLOW OVERBURDEN GROUNDWATER
POTENTIOMETRIC SURFACE CONTOUR MAP (APRIL 14, 2019)
FIGURE 5
10338.029
AS NOTED
WAB/JNB
2019-08-05
DWB
DWB
500
4
6
0
4
8
0
5
0
0
500
480
4
6
0
4
4
0
4
2
0
440
420
/
, , /
, , /
, , /
, , /
, , /
, , /
, , /
, ,
INTERCEPTOR WELL ;f' .J-~-~==:- // ~/
PZ-~ =_,//
G-26 8_ 3 ~ \.. H-2~~
- •- G-=25. _ ♦ ✓'. H-27 -:::;.:~ ~ ~ .,...---~;:;;,;- .._ -- .-- ----.._ _./r , __. ------
'-LtMt ~ ;::_ --- -- --- ~--~ ----------- ~
WELL #2 GREENWOOD RESIDENCE
AND FACILITY MAINTENANCE BUILDING
\ PARCEL
4-505-890
WELL #3 MISSING LINK ROAD
WATER SUPPLY
SCALE: 1" = 200'
0 100 200 400
NOTES
PARCEL 4-505-897
600
1) MONITORING WELLS USED TO DEVELOP THE SHALLOW OVERBURDEN GROUNDWATER POTENTIOMETRIC CONTOURS INCLUDE ALL GAS EXTRACTION WELLS (EW-1 THRU EW-39) AND WELLS A-1 S, A-2S, 8-7, B-13S, PZ-F1, D-19, E-21, C-15, J-36, P-1 & P-2.
PROJECT Till.E:
SHEET Till.E:
I
I
T OF(~~~ ~~---..:-:..~c-: -----•-- ~ ~ ' ~TIRE CHIP,
~ 32 (~73:) ~ R:2 (513.7)'-~ (DRY) o(EDWRY3:Z ~ (DRY) o o EW~35 J EW-37 .::= (DRY) ) EW ;8 ), -~~
(pwRIJ --- __. ___ ::::-=:- =::-_.=-..:::::::: = _ _ oEW 22 EW 39 (DRY) ~l 0 - - (DRY)O
0 ( ) EW 1~DRY) ./4
(DRY)
DWG:
JN:
SCALE:
(DRY) EW 25
0
DRY 4-505-894
0 EW 16
BY:
DATlE:
APPROVED BY:
CHECKED BY:
0 EW 21 /.
0 EW 18
(DRY)
REV:
REV DATlE:
ISSUE:
ISSUE DATlE:
(DRY) EW 20
0
0 /4
~ , (443.98)
•••••••••••
- -(100.0)
> ♦ MW-10
DESCRIPTION:
DESCRIPTION:
\ \
\ \
\
\ \
\
\ \
\
RUMRILL SPRING
\ \
\
\
(NOT IN USE SINCE 2013)
~
\ \
\ \
\
\
\ \
'\, PARCEL
4-505-949 ' ' '\,
LEGEND LANDFILL SOLID WASTE BOUNDARY
PROPERTY BOUNDARY (APPROXIMATE)
SHALLOW OVERBURDEN GROUNDWATER POTENTIOMETRIC SURFACE CONTOUR (DASHED WHERE INTERPRETED)
GROUNDWATER ELEVATION
INTERPRETED FLOW DIRECTION
---
WELL USED FOR POTERTIOMETRIC SURFACE
• •
Engineers Environmental Scientists Surveyors
DISPOSAL SPECIALISTS, INC. LANDFILL
MISSING LINK RD (ROUTE 5) - ROCKINGHAM, VERMONT
SHALLOW BEDROCK GROUNDWATER
POTENTIOMETRIC SURFACE CONTOUR MAP (APRIL 14, 2019)
FIGURE 6
10338.029
AS NOTED
WAB/JNB
2019-08-05
DWB
DWB
300
3
0
0
3
5
0
4
0
0
4
5
0
5
0
0
5
0
0
450
400
350
300
, , /
, , /
, ,
INTERCEPTOR WELL ;f' .J-~-~==:- // ~/
WELL #2 GREENWOOD RESIDENCE
AND FACILITY MAINTENANCE BUILDING
\ PARCEL
4-505-890
WELL #3 MISSING LINK ROAD
WATER SUPPLY
SCALE: 1" = 200'
0 100 200 400
NOTES
/ , , , /
, , /
, , /
, , /
~ (547.: ) _,,,,, ,,/ PZ-H2 - /
/ -,/ ..G- 2
~~ :------- 8-3
,,(' .---: -;;.:=;--=-=-- -~G:.25.(~G_- - - - .l5; 4) =, I PZ-OF1 ,.- ~ ,.::--~ - _ _ .-- ----::: ___ _.//" ' ---
PARCEL 4-505-897
600
r .... ,roFs ---·--- ....______..-- ••• ~ :...---EW-30 OL/D WA5iE~ •~• ••• -
\ r /. ._ - 0 EW-31 -------~ '-.. I / / - - O EW 32 ............ '-.
EWo2 r_$ 1 5 EW33 EW34 -...._-...._
[) ROUTE 5 SLOPE STABILIZATION AND SEEPAGE CONTROL SYSTEM 20,000 GALLON ABOVE GROUND STORAGE TANK
' '
I
I
EW 29 0
I I
\
EW 13 0
----
1 ROUTE 5 SLOPE ' STABILIZATION AND \ SEEPAGE CONTROL
' ' \ I I
\
SYSTEM
PARCEL 4-505-894 EW o 19
EW 25 EW 16 0
DANFORTH WELL
PARCEL 4-107-032
0 o EW 18 EW 20
EW 17 0
---- ------ ---- --
oEW 22
EW 21 0
PARCEL 4-107-014
(BAN HOLZER) \ _.. SRW-3
\ \ ------rr?J"VER LEGEND
1) MONITORING WELLS USED TO DEVELOP THE SHALLOW BEDROCK GROUNDWATER POTENTIOMETRIC CONTOURS INCLUDE WELLS C-17, E-23, G-25, H-27, J-37, PZ-H2, K-39, MW-3, MW-6, MW-9 & 8-3.
\ -- -_ JN--£--C rt cu -♦-MW--9--M-O-NI-TO-RI-NG-WE-LL ______ _
--~\.,-------coN O EW 11A GAS EXTRACTION WELL S RW-2 S RW-4 CT RIVER OR SEEP SAMPLING LOCATION
£ FORMER WATER SUPPLY WELL (NOT IN USE)
PROJECT Till.E: DWG: BY: REV: DESCRIPTION:
DATE: REV DATE:
SHEET Till.E: JN: APPROVED BY: ISSUE: DESCRIPTION:
SCALE: CHECKED BY: ISSUE DATE:
•••••••••••
(100.0)
> ♦ MW-10
\ \
\ \
\
\ \
\
\ \
\
\ \
\
\ \
\
\ \
\ RUMRILL SPRING \
(NOT IN USE SINCE 2013)
~
, PARCEL ', 4-505-949
' ' '\ \
\
'\
, ,, /
\ --'
RW-4
LEGEND
--
LANDFILL SOLID WASTE BOUNDARY
PROPERTY BOUNDARY (APPROXIMATE)
SHALLOW BEDROCK GROUNDWATER POTENTIOMETRIC SURFACE CONTOUR (DASHED WHERE INTERPRETED)
GROUNDWATER ELEVATION
INTERPRETED FLOW DIRECTION
--
WELL USED FOR POTENTIOMETRIC SURF AC
• •
Engineers Environmental Scientists Surveyors
DISPOSAL SPECIALISTS, INC. LANDFILL
MISSING LINK RD (ROUTE 5) - ROCKINGHAM, VERMONT
DEEPER BEDROCK GROUNDWATER
POTENTIOMETRIC SURFACE CONTOUR MAP (APRIL 14, 2019)
FIGURE 7
10338.029
AS NOTED
WAB/JNB
2019-08-05
DWB
DWB
300
500
5
0
0
4
5
0
4
5
0
4
0
0
4
0
0
3
5
0
3
0
0
350
300
/
, , /
, , /
, , /
, , /
, , /
, , /
, , /
, ,
8-3
INTERCEPTOR WELL ;f' .J-~-~==:- // ~/
PZ-~ j(//~~ , (487.3)
H-2~~
....:. _ ___ ,____,__,.r-.;25. _ ♦ ✓'. H-27 e .._ ~ - - - - ----.... - _.//" , ----~,-- .....
WELL #2 GREENWOOD RESIDENCE
AND FACILITY MAINTENANCE BUILDING
\ PARCEL
4-505-890
WELL #3 MISSING LINK ROAD
WATER SUPPLY
LIMtr OF soti~ - - - '-- --- - - ------~- ~ - -D IVASTE'~ ------~i:::--
0 EW 5
EW 32 0
EW 29 0
EW 13 0
C-15
EW 3 0
EW 25 0
PARCEL 4-505-894 EW o 19
0 EW 17
oEW 22
EW 21 0
EW 39 0
HIT OR MISS CLUB WELL
---,-\ .... ------ \
- I
SCALE: 1"
0 100 200
NOTES
= 200'
400
PARCEL 4-505-897
600
[) ROUTE 5 SLOPE STABILIZATION AND SEEPAGE CONTROL SYSTEM 20,000 GALLON ABOVE GROUND STORAGE TANK
1) MONITORING WELLS USED TO DEVELOP THE DEEPER BEDROCK GROUNDWATER POTENTIOMETRIC CONTOURS INCLUDE WELLS K-40, H-28, J-38, MW-4, MW-7, MW-10, C-18, E-24 & G-26.
PROJECT Till.E:
SHEET Till.E:
I
I
I
I
I
\ I I
\ 1 ROUTE 5 SLOPE 1 STABILIZATION AND \ SEEPAGE CONTROL I I
\ I I
\
SYSTEM
PARCEL 4-107-032
-- ---- ------\ ..- SRW-3
---- PARCEL 4-107-014
(BAN HOLZER)
\ \ ------rr?J"VER LEGEND \ ..- -_ JN--£--C rt cu -♦-MW--9--M-O-NIT-O-RI-NG-WE-LL ______ _
--~1,,,-------coN O EW 11A GAS EXTRACTION WELL S RW-2 S RW-4 CT RIVER OR SEEP SAMPLING LOCATION
£ FORMER WATER SUPPLY WELL (NOT IN USE)
DWG: BY: REV: DESCRIPTION:
DATE: REV DATE:
JN: APPROVED BY: ISSUE: DESCRIPTION:
SCALE: CHECKED BY: ISSUE DATE:
■■■■■■■■■■■
- -(100.0)
> ♦ MW-10
\ \
\ \
\
\ \
\
\ \
\
\ \
\
\ \
\
\ \
\ RUMRILL SPRING \
(NOT IN USE SINCE 2013)
~
, PARCEL ', 4-505-949
' '
LEGEND LANDFILL SOLID WASTE BOUNDARY
PROPERTY BOUNDARY (APPROXIMATE)
DEEPER BEDROCK GROUNDWATER POTENTIOMETRIC SURFACE CONTOUR (DASHED WHERE INTERPRETED)
GROUNDWATER ELEVATION
INTERPRETED FLOW DIRECTION
WELL USED FOR POTENTIOMETRIC SURF ACE
• •
APPENDIX B
GRAPHS OF TRENDS FOR
WELLS WITH COCS EXCEEDING IGCLS
0
100
200
300
400
500
600
700
800
900
10005/
2/20
04
6/21
/200
6
8/9/
2008
9/28
/201
0
11/1
6/20
12
1/5/
2015
2/23
/201
7
4/14
/201
9
Conc
entr
atio
n (µ
g/L)
Sample Date
Arsenic MW-3Multi - Well Time Series Graph
Clean-Up Standard 10 µg/L MW-3 Arsenic
Manganese - MW-3 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
500
1000
1500
2000
2500
3000
Clean-up Standard 180 ug/L MW-3
5/12
/200
4
6/29
/200
6
8/16
/200
8
10/4
/201
0
11/2
0/20
12
1/8/
2015
2/25
/201
7
4/15
/201
9
• □
Methylene Chloride - MW-3 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
5
10
15
20
25
30
Clean-up Standard 5 ug/L MW-3
9/29
/201
5
3/31
/201
6
10/2
/201
6
4/5/
2017
10/7
/201
7
4/10
/201
8
10/1
2/20
18
4/15
/201
9
• □
Xylenes, Total - MW-3 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
500
1000
1500
2000
2500
3000
Clean-up Standard 400 ug/L MW-3
5/12
/200
4
6/29
/200
6
8/16
/200
8
10/4
/201
0
11/2
0/20
12
1/8/
2015
2/25
/201
7
4/15
/201
9
• □
Arsenic - MW-4 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
10
20
30
40
50
60
Clean-up Standard 10 ug/L MW-4
5/12
/200
4
6/30
/200
6
8/17
/200
8
10/5
/201
0
11/2
2/20
12
1/10
/201
5
2/27
/201
7
4/17
/201
9
• □
Manganese - MW-4 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
1000
2000
3000
4000
5000
6000
7000
8000
Clean-up Standard 180 ug/L MW-4
5/12
/200
4
6/30
/200
6
8/17
/200
8
10/5
/201
0
11/2
2/20
12
1/10
/201
5
2/27
/201
7
4/17
/201
9
• □
Arsenic - MW-6 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
50
100
150
200
250
300
Clean-up Standard 10 ug/L MW-6
5/4/
2004
6/23
/200
6
8/11
/200
8
9/30
/201
0
11/1
8/20
12
1/7/
2015
2/25
/201
7
4/17
/201
9
• □
Manganese - MW-6 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
500
1000
1500
2000
2500
3000
Clean-up Standard 180 ug/L MW-6
5/4/
2004
6/23
/200
6
8/11
/200
8
9/30
/201
0
11/1
8/20
12
1/7/
2015
2/25
/201
7
4/17
/201
9
• □
Manganese - MW-7 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
500
1000
1500
2000
Clean-up Standard 900 ug/L MW-7
5/4/
2004
6/22
/200
6
8/10
/200
8
9/29
/201
0
11/1
7/20
12
1/6/
2015
2/24
/201
7
4/15
/201
9
• □
Chromium - MW-9 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
100
200
300
400
500
Clean-up Standard 50 ug/L MW-9
5/11
/200
4
6/29
/200
6
8/16
/200
8
10/4
/201
0
11/2
1/20
12
1/9/
2015
2/26
/201
7
4/17
/201
9
• □
Manganese - MW-9 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
100
200
300
400
500
600
700
800
900
Clean-up Standard 180 ug/L MW-9
5/11
/200
4
6/29
/200
6
8/16
/200
8
10/4
/201
0
11/2
1/20
12
1/9/
2015
2/26
/201
7
4/17
/201
9
• □
Manganese - MW-B7 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
500
1000
1500
2000
Clean-up Standard 900 ug/L MW-B7
5/4/
2004
6/22
/200
6
8/10
/200
8
9/29
/201
0
11/1
7/20
12
1/6/
2015
2/24
/201
7
4/15
/201
9
• □
Methylene Chloride - MW-B13D Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
50
100
150
200
250
300
350
400
MW-B13D Clean-up Standard 5 ug/L
5/22
/200
3
8/28
/200
5
12/6
/200
7
3/14
/201
0
6/21
/201
2
9/28
/201
4
1/5/
2017
4/15
/201
9
I
\ \ \ \ \ .. ~ -._ A _ ~ --- : - -
I I I I I I
•
Arsenic - MW-B13D Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
50
100
150
200
Clean-up Standard 10 ug/L MW-B13D
5/12
/200
4
6/29
/200
6
8/16
/200
8
10/4
/201
0
11/2
0/20
12
1/8/
2015
2/25
/201
7
4/15
/201
9
• □
Manganese - MW-B13D Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
1000
2000
3000
4000
5000
Clean-up Standard 180 ug/L MW-B13D
5/4/
2004
6/22
/200
6
8/10
/200
8
9/29
/201
0
11/1
7/20
12
1/6/
2015
2/24
/201
7
4/15
/201
9
• □
Manganese - MW-C15 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
1000
2000
3000
4000
5000
6000
Clean-up Standard 900 ug/L MW-C15
5/22
/200
3
8/28
/200
5
12/6
/200
7
3/15
/201
0
6/22
/201
2
9/30
/201
4
1/7/
2017
4/17
/201
9
• □
Manganese - MW-D19 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
5000
10000
15000
20000
Clean-up Standard 900 ug/L MW-D19
5/4/
2004
6/22
/200
6
8/10
/200
8
9/29
/201
0
11/1
7/20
12
1/6/
2015
2/24
/201
7
4/15
/201
9
• □
0
100
200
300
400
500
600
700
8005/
2/20
04
6/21
/200
6
8/9/
2008
9/28
/201
0
11/1
6/20
12
1/5/
2015
2/23
/201
7
4/14
/201
9
Conc
entr
atio
n (µ
g/L)
Sample Date
Manganese MW-E22Multi - Well Time Series Graph
Clean-Up Standard 180 µg/L MW-E22 Manganese
2-Butanone (MEK) - MW-E22 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
5000
10000
15000
20000
25000
30000
35000
40000
Clean-up Standard 170 ug/L MW-E22
5/10
/200
4
6/28
/200
6
8/15
/200
8
10/4
/201
0
11/2
1/20
12
1/10
/201
5
2/27
/201
7
4/18
/201
9
• □
Xylenes, Total - MW-E22 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
1000
2000
3000
4000
5000
6000
Clean-up Standard 400 ug/L MW-E22
5/10
/200
4
6/28
/200
6
8/15
/200
8
10/4
/201
0
11/2
1/20
12
1/10
/201
5
2/27
/201
7
4/18
/201
9
• □
2-Butanone (MEK) - MW-J35 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
5000
10000
15000
20000
25000
30000
Clean-up Standard 170 ug/L MW-J35
5/4/
2004
6/23
/200
6
8/11
/200
8
9/30
/201
0
11/1
9/20
12
1/8/
2015
2/26
/201
7
4/18
/201
9
• □
Arsenic - MW-J35 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
5
10
15
20
25
30
Clean-up Standard 10 ug/L MW-J35
5/12
/200
4
6/29
/200
6
8/16
/200
8
10/4
/201
0
11/2
1/20
12
1/9/
2015
2/26
/201
7
4/16
/201
9
• □
Manganese - MW-J35 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
1000
2000
3000
4000
5000
6000
7000
Clean-up Standard 180 ug/L MW-J35
5/12
/200
4
6/29
/200
6
8/16
/200
8
10/4
/201
0
11/2
1/20
12
1/9/
2015
2/26
/201
7
4/16
/201
9
• □
0
200
400
600
800
1000
1200
1400
16005/
2/20
04
6/21
/200
6
8/9/
2008
9/28
/201
0
11/1
6/20
12
1/5/
2015
2/23
/201
7
4/14
/201
9
Conc
entr
atio
n (µ
g/L)
Sample Date
Methylene Chloride MW-J35Multi - Well Time Series Graph
Clean-Up Standard 5 µg/L MW-J35 Methylene Chloride--e-
Manganese - MW-J37 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
1000
2000
3000
4000
5000
Clean-up Standard 180 ug/L MW-J37
5/12
/200
4
6/30
/200
6
8/17
/200
8
10/5
/201
0
11/2
3/20
12
1/11
/201
5
2/28
/201
7
4/19
/201
9
• □
Arsenic MW-J37 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
5
10
15
20
Clean-up Standard 10 ug/L , MW-J37
6/13
/201
7
9/17
/201
7
12/2
2/20
17
3/29
/201
8
7/3/
2018
10/8
/201
8
1/12
/201
9
4/19
/201
9
.,)0
/
I I I I I I
• □
Manganese - MW-J38 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
500
1000
1500
2000
2500
3000
Clean-up Standard 900 ug/L MW-J38
5/4/
2004
6/23
/200
6
8/11
/200
8
9/30
/201
0
11/1
9/20
12
1/8/
2015
2/26
/201
7
4/18
/201
9
• □
Manganese - MW-K39 Multi-Well Time-Series Graph
Sample Date
Con
cent
ratio
n (U
G/L
)
0
500
1000
1500
2000
Clean-up Standard 900 ug/L MW-K39
5/4/
2004
6/23
/200
6
8/11
/200
8
9/30
/201
0
11/1
8/20
12
1/7/
2015
2/25
/201
7
4/16
/201
9
• □
APPENDIX C – DATA TABLES
Table 4
Summary of Interim Groundwater Cleanup Level (IGCL) Exceedences April 2019 Five Year Review Sampling
BFI-Rockingham Sanitary Landfill Superfund Site
17
0
5 5 0.7 5 2
40
0
10
50
18
0 /
90
0
1 6 1
2-B
uta
no
ne
B
en
zen
e
M
eth
yle
ne
Ch
lori
de
T
etr
ach
loro
eth
en
e
T
rich
loro
eth
en
e
V
inyl
Ch
lorid
e
X
yle
ne
s,
To
tal
A
rse
nic
*
C
hro
miu
m
M
an
ga
ne
se
**
Bis
(2
-ch
loro
iso
pro
pyl
) e
the
r
Bis
(2
-eth
yl h
exy
l) p
hth
ala
te
Pe
nta
chlo
rop
he
no
l
To
tal #
of
Exc
ee
da
nce
s
By
We
ll
MW-3 X X X X 4
MW-4 X X X 2
MW-6 X X X X 2
MW-7 X X X 1
MW-9 X X X X 2
MW-10 X X 0
MW-B3 0
MW-C17 X 0
MW-C18 X 0
MW-E23 X 0
MW-E24 X X 2
MW-G25 X 0
MW-G26 0
MW-H27 0
MW-H28 0
MW-J37 X X X 2
MW-J38 X X X 1
MW-K39 X 1
MW-K40 X X
9
MW-B7 X 1
MW-B13D X X X X 3
MW-C15 X 1
MW-C16 X X 0
MW-D19 X X 1
MW-E21 X 0
MW-E22 X X X X 3
MW-J35 X X X X X 5
MW-J36
6
To
tal #
of
Exc
ee
da
nce
s
By
Pa
ram
ete
r
Oct
ob
er/
No
vem
be
r 2
01
8
2 0 3 0 0 0 3 7 1 15 0 0 0
Notes:
X
X
*
**
***
Semivolatile Organic
Compounds
Parameter reported above laboratory detection limit but concentration is below the IGCL cleanup criteria
Parameter reported above laboratory detection limit and reported concentration exceeds the IGCL cleanup criteria
Parameter reported as Not Detected; however laboratory detection limit is above the IGCL cleanup criteria indicated.
Interim Groundwater Cleanup Levels (IGCLs) established in the 1994 ROD for bedrock compliance wells. The IGCL for arsenic was reduced from 50 to 10 ug/L and the IGCL for lead was reduced from 20 to 15 ug/L in the First Explanation of Significant Differences (ESD), dated September 29, 2014.
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
The cleanup level for manganese is 180 ug/L unless manganese is the only metal above the cleanup level, then a cleanup level of 900 ug/L is used.
Overburden groundwater quality is compared to IGCLs when assessing the progress of the site remedy.
Parameter Group Volatile Organic Compounds
Interim Groundwater Cleanup Level (IGCL) -
µg/L
Metals
Parameter /Well ID
Ove
rbu
rde
n W
ells
**B
ed
rock
Mo
nito
ring
We
lls
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Table 5: Summary of Analytes in Bedrock Monitoring Wells Exceeding IGCLs
Screened Unit Well Analyte IGCL
(ug/L)
USEPA MCL & VTDEC Standard
Spring 2019 Concentration
(ug/L)
Average Concentration
(ug/L)
Statistical Trend
Visual Trend
SBR MW-3
Arsenic 10 10 432 337 None Decreasing
Manganese* 180 300 1,210 1285 Increasing Increasing
Methylene Chloride 5 5 29 21 NA NA
Xylenes, Total 400 10,000 1,400 827 None None
DBR MW-4 Arsenic 10 10 30.5 25 None None
Manganese* 180 300 4,600 4418 Decreasing Decreasing
SBR MW-6 Arsenic 10 10 161 182 Decreasing Decreasing
Manganese* 180 300 1,570 1604 Decreasing Decreasing
DBR MW-7 Manganese* 900 300 1,600 1470 Decreasing Increasing
SBR MW-9 Chromium 50 100 267 142 None Increasing
Manganese* 180 300 416 397 None Increasing
DBR MW-E24 Arsenic 10 10 18.9 19 NA NA
Manganese* 180 300 382 341 NA NA
SBR MW-J37 Arsenic 10 10 10.4 5 NA NA
Manganese* 180 300 2,030 2720 Decreasing Decreasing
DBR MW-J38 Manganese* 900 300 2,450 1441 Increasing Increasing
DBR MW-K39 Manganese* 900 300 977 939 None None
Notes: USEPA MCL = United States Environmental Protection Agency Maximum Contaminant Level (most current). The EPA has not issued a Maximum Contaminant Level (MCL) for manganese VTDEC = Vermont Department of Conservation Interim Groundwater Quality Standards (revised 12/27/2013) IGCL = Interim Groundwater Cleanup Level for bedrock wells identified in the Remedial Statement of Work NA = Not analyzed. Data set not suitable for Mann-Kendall (does not contain minimum number of detections needed) NS = Not sampled in 2017 due to insufficient volume of water in the well U = Not detected above reported laboratory detection limit, as indicated J = Estimated value J+ = Biased high, likely higher than the true value J- = Biased low, likely lower than the true valueR = Rejected, due to matrix spike (MS) and/or matrix spike duplicate (MSD) recoveries being outside the control limitsAverage Concentration = The average concentration was calculated using data from the three most recent consecutive samplingevents, if available. The values used to calculate the average concentration are noted in Appendix G^ = Value exceeds the IGCL Standard, but meets USEPA and VTDEC Drinking Water Standards* = The IGCL for manganese is 180 ug/L if multiple metals are reported above the IGCL or 900 ug/L if manganese is the onlymetal reported above the IGCL** = Not sampled in Spring 2017 due to insufficient water. The anomalously high arsenic concentration reported in Spring 2012was excluded when calculating an average arsenic concentration at MW-3SBR = Shallow BedrockDBR = Deep Bedrockug/L = micrograms per liter or parts per billionTrend = Trend is based on Mann-Kendall statistical analysis and qualitative analysisNone = No trendDecreasing = Increasing trend at 95% confidence intervalIncreasing = Decreasing trend at 95% confidence intervalI-S or D-S = Increasing/Decreasing trend; however, time series graphs for recent data visually shows no trend.
Table 6: Summary of Analytes in Overburden Monitoring Wells Exceeding IGCLs
Screened Unit Well Analyte IGCL
(ug/L)
USEPA MCL & VTDEC
Standard
Spring 2019 Concentration
(ug/L)
5- YearAverage
Concentration (ug/L)
Statistical Trend Visual
Trend
DOB MW-B7 Manganese* 900 300 1,840 1298 None Increasing
DOB MW-B13D
Methylene Chloride 5 5 26 <23 None None
Arsenic 10 10 31.9 44 Decreasing Decreasing
Manganese* 180 300 492 703 None Decreasing
DOB MW-C15 Manganese 900 300 5,500 3,108 None Increasing
DOB MW-D19 Manganese 900 300 4,640 3,821 None Increasing
DOB MW-E22
2-Butanone 170 511** 5,700 21,220 Increasing Decreasing
Xylenes, Total 400 10,000 3,200 2,474 Increasing Increasing
Manganese* 180 300 487 613 None Decreasing
DOB MW-J35
2-Butanone 170 4,200** 23,000 20,200 None Increasing
Methylene Chloride 5 5 420 676 Increasing Increasing
Xylenes, Total 400 10,000 1,600 1,420 Increasing Increasing
Arsenic 10 10 16.1 18 None None
Manganese* 180 300 4,390 4,744 Increasing Increasing
Notes: USEPA MCL = United States Environmental Protection Agency Maximum Contaminant Level (most current). The EPA has not issued a Maximum Contaminant Level (MCL) for manganese VTDEC = Vermont Department of Conservation Interim Groundwater Quality Standards (revised 12/27/2013) IGCL = Interim Groundwater Cleanup Level for bedrock wells identified in the Remedial Statement of Work NA = Not analyzed. Data set not suitable for Mann-Kendall (does not contain minimum number of detections needed) NS = Not sampled in 2016 due to insufficient volume of water in the well U = Not detected above reported laboratory detection limit, as indicated J = Estimated value J+ = Biased high, likely higher than the true value J- = Biased low, likely lower than the true value R = Rejected, due to matrix spike (MS) and/or matrix spike duplicate (MSD) recoveries being outside the control limits Average Concentration = The average concentration was calculated using data from the four most recent consecutive sampling events, if available. The values used to calculate the average concentration are noted in Appendix G ^ = Value exceeds the IGCL Standard but meets USEPA and VTDEC Drinking Water Standards * = The IGCL for manganese is 180 ug/L if multiple metals are reported above the IGCL. The IGCL for manganese is 900 ug/L if manganese is the only metal reported above the IGCL ** = The USEPA has not issued a standard for 2-Butanone (Methyl Ethyl Ketone). The VTDEC standard is 511 ug/L as of July 6, 2019 *** = Detection limit for analyte has historically been reported above the IGCLs and analyte has historically been detected at concentrations that exceeded the IGCLs; therefore, analyte is listed as an exceedance SOB = Shallow OverburdenDOB = Deep Overburden ug/L = micrograms per liter or parts per billionTrend = Trend is based on Mann-Kendall statistical analysis and qualitative analysis None = No trend Decreasing = Increasing trend at 95% confidence intervalIncreasing = Decreasing trend at 95% confidence intervalI-S or D-S = Increasing/Decreasing trend; however, time series graphs for recent data visually shows no trend.
Results USEPA
Health
Advisory
VTDEC
Groundwater Standard
Missing Link
Water Supply
Well 2 Pre
Missing Link
Water Supply
Well 2 Pre DUP
Missing Link
Water Supply
Well 2 Post
Missing Link
Water Supply
Well 3 Pre
Missing Link
Water Supply
Well 3 Post
FIELD BLANK EQUIPMENT
BLANKMW-B3
EBMW-J35
EB MW-7 MW-10 EB
MW-J37 EB
MW-J38 FB
4/15/2019 4/15/2019 4/15/2019 4/15/2019 4/15/2019 4/15/2019 4/15/2019 4/15/2019 4/16/2019 4/15/2019 4/15/2019 4/19/2019 4/15/2019
Sampling Method Grab Grab Grab Grab Grab Grab GrabPortable Bladder
Pump
Portable Bladder
PumpDedicated Bailer
Portable Bladder
Pump
Portable Bladder
Pump
Dedicated
Submersible
StratumDeep Bedrock
Side Gradient
Deep Bedrock
Side Gradient
Deep Bedrock
Side Gradient
Deep Bedrock
Side Gradient
Deep Bedrock
Side GradientNA NA
Upgradient Deep
Bedrock
Downgradient
Shallow OB
Downgradient
Deep Bedrock
Downgradient
Deep Bedrock
Downgradient
Deep Bedrock
Downgradient
Deep Bedrock
Screen Depth (ft-bgs) NA NA 48.8-58.8 30-40 170-190 90-110 50-60 97.8-111.2
Sand Pack (ft-bgs) NA NA NA NA NA NA NA 3.8-58.8 28-42 155-190 85-110 48-61 100-110
1,4-Dioxane (µg/L) 0.2 0.2U 0.2U 0.2U 0.2U 0.2U 3.9 22 0.2U 32000 63 0.21U 1.2U 6
Perfluorobutanesulfonic acid
(PFBS) (ng/L)1.9U 2U 2U 2U 1.9U 1.8U 1.9U 1.8U 36 2.9 1.8U 11U 13
Perfluoroheptanoic acid
(PFHpA) (ng/L)1.9U 2U 2U 2U 1.9U 1.8U 1.9U 1.8U 120 3.4 1.8U 11U 9.5U
Perfluorohexanesulfonic acid
(PFHxS) (ng/L)1.9U 2U 2U 2U 1.9U 1.8U 1.9U 1.8U 58 1.8U 1.8U 11U 9.5U
Perfluorononanoic acid
(PFNA) (ng/L)1.9U 2U 2U 2U 1.9U 1.8U 1.9U 1.8U 9.7U 1.8U 1.8U 11U 9.5U
Perfluorooctanesulfonic acid
(PFOS) (ng/L)70 1.9U 2U 2U 2U 1.9U 1.8U 1.9U 1.8U 9.7U 1.8U 1.8U 11U 9.5U
Perfluorooctanoic acid
(PFOA) (ng/L)70 1.9U 2U 2U 2U 1.9U 1.8U 1.9U 1.8U 150 1.8U 1.8U 11U 9.5U
USEPA COMBINED (ng/L)
(PFOS & PFOA)70 1.9U 2U 2U 2U 1.9U 1.8U 1.9U 1.8U 150 1.8U 1.8U 11U 9U
VTDEC COMBINED (ng/L)
(PFOA, PFOS, PFHxS, PFHpA
and PFNA)
20 1.9U 2U 2U 2U 1.9U 1.8U 1.9U 1.8U 328 3.4 1.8U 11U 9U
Notes:
Table 7: Summary of 1,4-Dioxane and PFAS in Select Groundwater Monitoring and Drinking Water Supply Wells
150 Exceeds USEPA Health Advisory
328 Exceeds VTDEC Groundwater Enforcement Standard
DUP - Duplicate sampleEB - Sample results related to equipment blank result. Portable bladder pump used for sampling was deconned and fitted with a new, PFAS-free
bladder. Bold values flagged due to probable field and/or equipment blank cross-contaminationU = Not Detected at listed detection limit
OB -Overburden
NA - Not applicable
NS - No sample collected
NS Dry - No sample well dry
0.3
APPENDIX D – SITE BACKGROUND
A. SITE BACKGROUND
Physical Characteristics The BFI-Rockingham Landfill Superfund Site (the “Site”), also known as the Disposal Specialist, Inc. (DSI) Landfill, is located along U.S. Route 5, locally known as Missing Link Road, in the Town of Rockingham, Windham County, Vermont as shown on Figure 1 in Appendix B. The 17-acre solid waste landfill is located on a terrace approximately 500 feet from and 200 feet higher in elevation than the Connecticut River floodplain and wetlands are present at the base of the steep slopes at the bank of the Connecticut River. However, wetlands and floodplain areas are not present with the 25-acre area that encompasses the landfill and operating facility, which consists of an office building, garage, former solid waste transfer station with associated former storage areas, and landfill gas management system. The Site includes the landfill area and the abutting rural residential areas impacted by the Site as shown on Figure 2. Sampling locations including the Missing Link wells and water supply system are also shown on Figure 2.
Geology The landfill occupies approximately 17 acres and is situated on a glacial terrace located along the west side of the Connecticut River. Geological cross sections prepared as part of the RI/FS are included as Figures 3 and 4 in Appendix B. Most waste within the landfill is underlain by a relatively thin layer of sand deposits overlying varved lacustrine deposits comprised of interbedded clay and silt. The lacustrine deposits and bedrock are generally separated by a sandy glacial till unit. From top to bottom the overburden sediments include a sand and silty sand, varved clayey silt, silty sand grading downward to sand and glacial till. Overburden sediments are approximately 200 feet thick on the southeast side of the landfill, with little or no overburden present on the northwest side of the landfill. Bedrock under the Site consists of moderately fractured black and gray phyllite and slate of the Littleton Formation. Sulfide minerals are present within fractures, and fractures in rock core and outcrops were frequently coated with reddish brown oxides. The dominant fractures within the bedrock are foliation parallel and are near-vertical to steeply dipping and north-northeast trending. A less common cross-foliation fracture population oriented perpendicular to foliation that are much shorter in length than foliation-parallel fractures. In some areas, located along the west side of the landfill, waste may be situated in close proximity to bedrock and precipitation percolating through the waste mass in these areas may infiltrate into the fractured bedrock. Hydrology The varved lacustrine deposits underlying the majority of the landfill impedes the vertical/downward migration of water beneath the landfill resulting in predominantly horizontal flow within the overlying sand deposits. As shown on the interpreted potentiometric surface contour map for shallow overburden groundwater (Figure 5 in Appendix B), overburden groundwater at the Site flows easterly towards the Connecticut River. Groundwater elevations at shallow and deeper overburden well couplets indicate that there is a component of downward flow. Water levels in shallow overburden declined after the installation of the landfill cap; however, water levels in deeper overburden (varved lacustrine deposits) did not respond significantly to landfill capping. The majority of the impacted shallow overburden groundwater is currently intercepted by the Route 5 Seepage Control and Stabilization System (Route 5 System) located on the western side of Route 5, which was constructed to collect groundwater formerly discharging to a drainage ditch via seeps along Route 5. The base of the trench intersects the geological transition from fine sands to laminated/varved
clayey silt at an elevation of 420 feet NGVD. Groundwater collected by the Route 5 System is disposed at an off-site disposal facility. The Route 5 System intercepted the majority of the seeps identified in the RI, however, one impacted seep (Seep SW-6) continues to flow on a seasonal basis. The occurrence of flow at this location has appeared to decrease significantly over time in in relation to installation of the cap and seepage control system. Interpreted potentiometric surface contour maps for shallow bedrock and deeper bedrock are included as Figure 6 and Figure 7 in Appendix B, respectively. Shallow bedrock is represented by monitoring wells generally screened within the upper 10 feet of bedrock, while deeper bedrock wells are generally screened greater than 50 feet from the bedrock surface. On a site-wide scale the horizontal component of groundwater flow in shallow and deeper bedrock flows is to the southeast toward the Connecticut River. However, while Figures 6 and 7 provide the general direction of groundwater flow, the actual flow pathways in bedrock are likely more complex because flow in fractured bedrock is strongly controlled by the number, aperture (size), orientation and interconnectivity of bedrock fractures, as well as the tortuosity of flow paths within individual fractures. Bedrock ground water discharges to the Connecticut River valley located approximately 500 feet to the east of the landfill boundary.
Land and Resource Use
The land use within a one-mile radius of the Site supports primarily low-density rural residential housing, light agriculture, undeveloped forest land and commercial activities. Approximately 2,700 people live within one mile and 6,400 people live within three miles of the Site. The PRPs supply water via the Missing Link Road Non-Public Water System to four residential properties located between the landfill and the Connecticut River. Several private residential water supply wells in the vicinity of the Site are sampled periodically. Natural resources near the Site include groundwater, surface water, fish and game, arable land, forest, woodland and minerals. The current and future land use of the landfill itself is non-residential because of the impracticability of constructing residences on a closed sanitary landfill. Current land-use restrictions prevent development that could damage the landfill cap. The areas surrounding the landfill are considered residential. However, much of the area surrounding the landfill is not suitable for development due to steep topography, proximity of floodplains and development setbacks from the Connecticut River. Groundwater usage restrictions (groundwater reclassification and Water Supply Agreements recorded at the Registry of Deeds) have been established to restrict the use of groundwater at properties located downgradient of the DSI Landfill. Water Supply Agreements have been recorded at the Registry of Deeds for the four residences that the PRPs supply potable water to via the Missing Link Road Non-Public Water System. The groundwater aquifer below the landfill property and properties located between the landfill and the Connecticut River was reclassified from Class III to Class IV groundwater by VTANR on March 10, 2009 (amended November 6, 2013). Class IV groundwater is not suitable for potable use. The current ICs (groundwater reclassification, Water Supply Agreements and deed restrictions on BFI-owned property) established to restrict the use of bedrock groundwater at properties located downgradient of the landfill area and within the Site-related impacted groundwater area are protective of human health and documented in the 2014 ESD. Prior to the implementation of the site remedy, an Ecological Risk Assessment, as discussed in the ROD, concluded that high aluminum, chromium, iron and lead concentration in the Connecticut River that were attributable to seeps within the hydraulic influence of the landfill posed a threat to ecological receptors in the Connecticut River. However, the installation of the Route 5 System eliminated the majority of the seepage areas, and monitoring results from Connecticut River samples collected during long-term monitoring activities have met ambient water quality criteria for many years, which indicate the landfill is not adversely affecting the Connecticut River.
History of Contamination
Prior to the 1960’s, the Site was an undeveloped woodland. Landfill operations at the Site first started in 1968 (under the ownership of Harry K Shepard, Inc.) following the removal of significant quantities of borrow material (fill) from the property for the construction of Interstate 91. In 1969, Harry K Shepard, Inc. deeded the landfill to Disposal Specialist, Inc., and Harry K Shepard, Inc. was continued as a solid waste and industrial waste hauling company. The DSI landfill and Harry K Shepard, Inc. were acquired by Browning-Ferris Industries, Inc. (BFI) in 1973, and Harry K Shepard, Inc. subsequently changed its name to Browning-Ferris Industries of Vermont, Inc. (BFI-VT). From 1968 until 1991, the landfill received residential, commercial and industrial solid and liquid waste. Approximately 1.2 million cubic yards of solid waste were disposed in the landfill during its operation. The majority of wastes were placed in unlined landfill cells, with the exception that municipal incinerator ash was placed in a lined monofill cell located in the southeastern section of the landfill from 1986 to 1989. The monofill cell was capped in 1989. Wastes continued to be disposed in the unlined landfill cells until landfilling activities at the Site ceased in November 1991. In 1989, BFI-VT installed an active landfill gas collection system to comply with the Vermont air pollution control regulations. Landfill gas is extracted from numerous gas extraction wells through an underground piping network and landfill gas is subsequently combusted at an on-site flare. The landfill gas collection and treatment system is currently operated and maintained pursuant to a permit issued by the Vermont Air Pollution Control Division. Neighbors began reporting potential groundwater quality impacts in 1977. In 1979, VTDEC collected and analyzed drinking water samples from six bedrock water supply wells located in the vicinity of the landfill. Metals and volatile organic compounds (VOCs) consistent with impacts attributable to the DSI landfill were reported in some of the bedrock water supply wells sampled, and the State of Vermont required DSI to provide residences located east of the landfill with bottled water for potable use. In 1980, a new water supply well was installed on DSI property and a distribution system was constructed to serve residents previously supplied with bottled water. DSI entered into an agreement to continue to supply off-site residences until EPA and VTDEC determine that the water beneath the residences is acceptable for use as a water supply. In the past, the overburden groundwater in the immediate vicinity of the landfill contained VOCs, SVOCs and metals attributable to the landfill. The overburden contamination was limited to the area east and hydraulically downgradient of the landfill and the east side of Route 5. Contaminants at shallow depths (in sandy overburden above varve lacustrine sediments) extended short distances to discharge points (seeps) at the top of ravines adjacent to the east side of Route 5 (EPA, 1994). A shallow overburden groundwater collection trench (the Route 5 Seepage Control and Stabilization System, the “Route 5 System”) was constructed in the fall and winter of 1992 to: 1) collect groundwater seepage discharging within the stormwater drainage ditch to the east of the landfill and immediately adjacent to Route 5; 2) reduce seepage below Route 5; and 3) reduce soil pore water pressure in a localized area along Route 5 to enhance the integrity of the proposed site remedy. The trench is bounded by sheet piling driven to an elevation of approximately 400 feet NGVD. The Route 5 System eliminated all but one seepage area (Seep SW-6) along Route 5 and has effectively removed impacted groundwater from the Site. A small amount of impacted groundwater currently discharges seasonally to Seep SW-6 on the east side of Route 5. However, constituents of concern in Seep SW-6 have been reported at concentrations below applicable stormwater standards. Bedrock groundwater between the landfill and the Connecticut River also contained VOCs, SVOCs and metals consistent with a release from the landfill. However, concentrations were significantly lower than in overburden. Arsenic and manganese were the primary contaminants of concern in bedrock
groundwater, which occur naturally in the bedrock fracture fillings, and were mobilized by a reducing condition attributable to the landfill. Initial Response
The State of Vermont has regulated the landfill’s operations under the Vermont solid waste management program since 1968. In 1979, VTDEC collected and analyzed groundwater samples from six bedrock wells in the vanity of the landfill. Because those samples were found to be contaminated by the landfill, the VTDEC required DSI to supply nearby residences with bottled water. In 1980, a new water supply well was installed on DSI property to service the residences via a water supply line. DSI entered into a water supply agreement with affected property owners to maintain the water line and provide potable water until VTDEC and EPA determine that groundwater on the properties is acceptable for use as a water supply (EPA, 1994). In 2014, BFI-VT/DSI was continuing to supply potable water to the residences and maintain the water line. A series of Assurance of Discontinuance Agreements between DSI and VTDEC required DSI to demonstrate that the landfill would not further degrade groundwater or surface water quality in the vicinity of the landfill. Consequently, beginning in 1979 a series of hydrogeological investigations were performed to investigate groundwater flow and water quality conditions at the landfill. In October 1989, the site was included on the EPA National Priorities List (NPL). During the spring of 1992, DSI and BFI-VT, the two Potentially Responsible Parties (PRPs) initiated negotiations with EPA to conduct a Remedial Investigation and Feasibility Study (RI/FS) in accordance with NCP requirements. An Administrative Order (AO), EPA Docket No. I-92-1053, for RI/FS activities was executed by the PRPs in July 1992 and became effective August 8, 1992. Pursuant to the AO, a shallow overburden groundwater collection trench (the Route 5 Seepage Control and Stabilization System, the “Route 5 System”) was constructed in the fall and winter of 1992. As part of the Superfund Accelerated Cleanup Model, EPA initiated a non-time critical removal action (NTRCA) for the Site in December 1992. In February 1993, EPA required the PRPs to prepare an engineering evaluation / cost analysis under the existing RI/FS Order to support the selection of a NTCRA for the Site. EPA signed an Action Memorandum on September 13, 1993 to initiate a NTCRA to install a multi-layer landfill cap and expand the active landfill gas collection and treatment system. The landfill cap and landfill gas collection and treatment system designs were completed in June 1994. Construction of the NTCRA was initiated in April 1994 and completed in July 1995. On September 21, 1994, the EPA issued the Record of Decision (ROD) for the Site describing remedial actions implemented and the basis for the selected site remedy; no further construction activities were required under the ROD. The selected site remedy identified in the ROD called for long-term monitored natural attenuation of surface water and groundwater quality impacts, maintenance of the multi-layer cap and landfill gas extraction system, and the continued operation and maintenance of the off-site potable water supply line, lined ash monofill cell leachate collection system and the Route 5 System. The ROD established IGCLs for bedrock groundwater based on the cumulative carcinogenic and non-carcinogenic risks posed to individuals drinking bedrock groundwater. Due to the limited extent and low yield, overburden groundwater was not considered to be a potential drinking water source or a current or future human exposure pathway; therefore, IGCLs were not established for overburden groundwater. The Consent Decree (CD) was executed by EPA on May 22, 1996 which established requirements related to the operation and maintenance of the components of the site selected remedy, the framework for the long-term monitoring activities and established interim goals (comparison levels) for assessing the restoration of bedrock groundwater quality.
Basis for Taking Action
A Remedial Investigation (RI) was performed at the Site from 1992 to 1994 (Balsam 1993 & 1994). The RI identified the landfill as the source of contamination found in bedrock and overburden groundwater downgradient of the Site. Surface water in the drainages along Route 5 was found to also contain Site-related contaminants. Table A-1 summarizes the contaminants in groundwater identified during the RI (EPA, 1994)
Table A-1
Remedial Investigation Groundwater Contamination Summary
Contaminant of Concern
Interim Groundwater Cleanup Level
(IGCL)
Average Concentration
(ug/L)
Maximum Concentration
(ug/L)
Frequency of Detection
2-Butanone 170* 18 370 2/34 Antimony 6 14 28 1/32 Arsenic 50* 49 282 18/32 Barium 1,000* 303 1,850 30/32 Benzene 5 6 17 10/34 Bis (2-chloroisoproyl) ether
1* 11 100 1/33
Bis (ethylhexyl) phthalate
6 8 62 10/33
Chromium 50* 5 81 5/32 Manganese 180*/900** 1,020 5,830 28/32 Nickel 100 30 102 14/32 Pentachlorophenol 1 3 3 1/34 Tetrachloroethylene 0.7* 5 12 2/34 Xylene, total 400* 82 1,200 11/34 Vinyl chloride 2 4 6 3/34
* Current Federal/State standards (ARARs) have been revised for the contaminants of concern indicated. ** The cleanup level for manganese is 180 ug/L unless manganese is the only metal above the cleanup level, then a cleanup level of 900 ug/L is used.
B. REMEDIAL ACTIONS
Remedy Implementation
No construction activities were required by the ROD. A long-term monitoring plan was approved by EPA in May 1996. The Institution Controls were completed in June 1996 by a “Grant of Environmental Restrictions and Right of Access” for seven parcels of land, including the landfill and adjoining areas. The deed restrictions affect seven parcels of land, which have been subsequently combined and/or subdivided into three parcels of land (as listed in Table 3 in the main body of the 5YR). The following is a summary of the IC requirements, with parcel identification numbers updated per Summit (2012e): The Capped Area (capped portion of Parcel 4-505-894): In this area, uses are prevented that disturb
the integrity of the landfill cap, the leachate collection system, the landfill gas management system, or
any or any other structures (e.g. Route 5 System groundwater collection trench) for maintaining the effectiveness of the Removal/Remedial Action.
The Groundwater Restriction Area (Parcel 4-107-032, and portions of Parcels 4-505-890 and 4-505-894): This area is defined as a portion of the Site where contaminants were detected above groundwater cleanup levels during the RI. In this area, use for groundwater as a drinking supply is prohibited.
The Waterline Restriction Area: Alterations or disturbances to the waterline that supplies potable water to residential properties are prohibited in this area. The restrictions apply to the water line supply well and all structures and equipment related to it, as well as the water line itself.
Additional Restrictions (Parcels 4-505-890, 4-505-894 and 4-107-032): Activities and uses that disturb the Removal Action and Remedial Action, as defined in the ROD, are prohibited in this area. EPA signed a Preliminary Closeout Report for the entire Site (NTRCA and Remedial Action) in September 1996 upon completion of the cap, which confirmed that no additional monitoring wells or other construction activities were necessary at the Site.
The ROD anticipated that IGCLs would be achieved 15 years after completion of the NTCRA. Long-term monitoring activities have shown significant improvements in groundwater and surface water quality following construction the NTCRA. Results from the Fall 2008 Semi-Annual Long-Term Monitoring Report indicated that the IGCLs had been met at many Site monitoring wells. However, review of sample results over time indicated IGCLs for benzene, total xylenes, tetrachloroethene, methylene chloride, 2-butanone, vinyl chloride, arsenic, manganese, barium and chromium may not be met for bedrock groundwater at some bedrock compliance wells located hydraulically downgradient of the landfill within the 15-year restoration estimate contained in the ROD and a Technical Impracticability (TI) waiver was considered for the Site in 2009. In the spring of 2009, following receipt of the Fall 2008 Semi-Annual Long-Term Monitoring Report (URS, 2009) results, EPA and BFI-VT entered into discussions regarding the need to conduct additional investigation to further evaluate the status of the natural restoration component of the site remedy, in support of an adjustment to the ROD (completion of an ESD). EPA and BFI-VT concurred that IGCLs would not likely be achieved in the 15-year time frame specified in the ROD (i.e., by 2010) at some bedrock wells and that meeting arsenic and manganese IGCLs would be problematic due to the naturally occurring presence of these metals in bedrock fracture fillings, therefore a Technical Impracticability (TI) waiver was considered for the Site. Subsequently, BFI-VT’s consultant Summit Environmental Consultants, Inc. (Summit) prepared a Field Investigation Work Plan (Summit 2009), to support a TI evaluation. In support of the TI evaluation, temporary modifications to the water quality sampling locations and parameters specified in the LTMP were proposed. The temporary modifications to the LTMP were subsequently approved by EPA and sampling activities were performed according to a modified sampling program during the semi-annual monitoring events in 2009 and 2010. Subsequent discussions within EPA determined that the TI waiver was not the preferred method of addressing the 15-year ROD requirement for ground water restoration in bedrock wells. Subsequently, EPA requested that BFI-VT prepare an Investigation Plan as discussed in Section V-2 of the SOW. Summit prepared an Investigation Plan (Summit 2012) that included additional response actions to be undertaken to ensure the continued protection of human health and the environment. EPA issued an approval of the Investigation Plan in a letter dated February 16, 2012. The additional actions implemented in the plan and subsequent investigation are summarized below: The Conceptual Site Model (CSM) to assess water quality trends, changes in Site conditions and the
potential for the Site to meet cleanup goals in the future (Summit 2012c) were updated.
Potential vapor intrusion pathways related to structures located downgradient of the landfill (Summit 2012d, 2014b) were evaluated. Vapor Intrusion pathways were assessed based on results from soil vapor/gas and groundwater sampling results from semi-annual sampling events in 2014 which were
reported in 2015. Binding provisions to supply potable water to the landowners on the properties downgradient of the
landfill until cleanup goals were met (Summit 2014d). It was confirmed that the water supply system installed to serve off-site residences meets existing
codes for public water lines. It should be noted that although the existing water supply system does not meet the definition of a Public Water Supply (PWS) and is therefore not regulated by the State of Vermont.
The State of Vermont expanded the Groundwater Reclassification Zone boundary to include two
additional properties to the north of the existing boundary. VTANR (2013) amended the existing Class IV reclassification zone and buffer area to included two additional properties north of the existing boundary based on Summit (2012e).
A review of the groundwater quality monitoring program was done to determine what monitoring was needed until cleanup criteria are met. Subsequently, an updated long-term monitoring program was completed after the 2014 Five Year Review and put in place in 2015 for the next FYR completed as part of this document.
Results of the Investigation Plan, completed under SOW Section V-2, formed the basis for the EPA Declaration for the Explanation of Significant Differences (ESD) for the Site completed in September 2014. The ESD was done to address why the bedrock groundwater cleanup at the site had not met the IGCLs established in the ROD within 15-years. The ESD also revised the IGCLs for arsenic and lead because of changes in federal and state standards for those chemicals. In addition, the ESD documented the expanded institutional control of groundwater reclassification done by the State of Vermont to prevent groundwater use at the site. Revised Timeframe for the Restoration of Bedrock Groundwater The timeframe for the restoration of bedrock groundwater was evaluated using long-term monitoring data (Summit 2014b). This evaluation determined that VOCs concentrations at bedrock compliance wells have decreased to concentrations at or approaching the IGCLs, such that they are no longer considered to be a driving factor for predicting the timeframe for the restoration of bedrock groundwater quality at the Site, and that the naturally occurring metals, arsenic and manganese, are the principle constituents of concern requiring an extended period of time to restore bedrock groundwater to the IGCLs established in the ROD. It is noted that similar challenges in achieving groundwater cleanup goals for arsenic and manganese have been observed at other landfill/CERCLA sites in New England due to their sensitivity to geochemical conditions within an aquifer, particularly the oxidation or reduction state. Data for arsenic and manganese in bedrock groundwater were assessed in 2014 and statistically significant decreasing trends for manganese at selected wells were used to estimate the timeframe for bedrock restoration in the ESD. It was noted that no long-term statistically significant trends were apparent for the arsenic data set; however, as discussed in the CSM Update (Summit 2012c), the mobility/solubility of arsenic, iron and manganese in groundwater are strongly controlled by redox sensitive microbial-mediated geochemical processes, and concentrations of redox sensitive metals will decrease as conditions transition to a more oxidizing environment. Given the limitations in the arsenic dataset and similarity of factors controlling the mobility/solubility of arsenic and manganese, it is assumed that arsenic concentrations should achieve the IGCL (or background concentrations) within a similar timeframe as manganese. Based on the assumptions used in the evaluation for the timeframe predictions, restoration of bedrock groundwater to the IGCLs established in the ROD will likely be achieved between 2050 and 2070, while the IGCLs established in the ROD for VOCs will likely be achieved by 2025. Based on the data from the past 5-years, the assumptions and estimates are reasonable and appear on track with the predictions.
However, as with all time frame estimations, they are subject to change based on the future monitoring results, revisions to cleanup standards (e.g., updated IGCLs to current EPA/VTDEC standards), limitations in the dataset and limitations of statistical tools.
System Operation/Operation and Maintenance
Operation costs for the previous 5YR period 2014-2018 are summarized below.
Table B-1
Annual Operations/O&M Costs (BFI-VT, 2014, written communication)
Year System Operation Cost 2018 $299,662 2017 $310,594 2016 $309,053 2015 $370,805 2014 $439,672
The original O&M cost prediction provided in the 1994 ROD for post closure O&M for a period of 5 to 30 years after the completion of the NTCRA ranged from $90,000 to $200,000 per year.
APPENDIX E – CHRONOLOGY
SITE CHRONOLOGY
Date Site-Related Activity / Event 1960’s Site location used as a borrow pit 1968 Disposal Specialist, Inc. (DSI) landfill begins operation after closure of "Old Springfield
Landfill" 1973 BFI of Vermont (BFI-VT) acquires DSI. 1980 Water supply well installed to serve the facility and adjacent residents 1986-1989 Municipal incineration ash disposed in a 1.5-acres lined cell at landfill 1989 DSI landfill is added to National Priorities List as BFI Sanitary Landfill 1989 BFI installs an active gas collection system to limit migration of landfill gas 1992 EPA enters into agreement with DSI and BFI-VT to perform site wide investigation 1993 EPA signs first cleanup decision, Action Memorandum, to initiate a Non-Time-Critical
Removal Action (NTCRA) to place a cap on the landfill and expand gas collection and treatment system
1994 EPA signed second cleanup decision, Record of Decision (ROD), identifying Long-Term Monitoring and Natural Attenuation as the long-term groundwater cleanup approach
1996 NTCRA completed (landfill cap, expanded active gas collection system. groundwater interceptor trench)
1996 EPA enters into agreement with DSI and BFI-VT to perform long-term monitoring 1999 EPA performs first five-year review 2004 EPA performs second five-year review 2009 State of Vermont reclassifies groundwater affected by the DSI Site at Class IV
groundwater to limit groundwater extraction for potable use. Jan. 2009 The Fall 2008 Semi-Annual Long-Term Monitoring Report indicates that the cleanup
criteria would not be met for bedrock groundwater at some monitoring points with the 15-year timeframe specified in the ROD.
June 2009 BFI-VT proposed a Technical Impracticability (TI) waiver for the site and submitted an investigation plan in support of a TI waiver.
2009-2010 EPA approved temporary modifications to Long Term Monitoring Program (LTMP) to support a TI waiver.
Sept. 2009 EPA performs third five-year review. Oct. 2011 EPA determines that a TI waiver is not preferred for the DSI Site and requests that BFI-
VT submit an Additional Investigation Plan as specified in the Statement of Work included in the CD.
Jan. 2012 BFI-VT submits Additional Investigation Plan, which is subsequently approved by EPA. Aug. 2012 BFI-VT submits Additional Investigation Plan reports: Conceptual Site Model Update
and Vapor Intrusion Evaluation. 2012 BFI-VT performs (as part of the Additional Investigation Plan) a regulatory review and
physical evaluation of the water system originally installed in 1980 to serve off-site residents. Upgrades and improvements are made including an iron and arsenic removal system, installation of particulate filters and reconfiguration of the conveyance system to allow better access to Primary and Backup supply wells.
Nov. 2012 BFI-VT submits draft petition to the State of Vermont to revise/expand the extent of the groundwater reclassification area to correct for inaccurate boundaries used for the 2009 reclassification order.
Apr. 2013 BFI-VT extends water supply line to serve one additional property (Rumrill) on River Front Drive because, BFI-VT proposed that the State of Vermont expand the groundwater reclassification zone buffer to include the Rumrill property in November
2012 and because, in Spring of 2013, Mr. Rumrill requested that BFI-VT extend the water line because his spring water source (located on BFI-VT property – outside the groundwater reclassification/buffer zone) was not operable.
June. 2013 BFI-VT submits DSI Missing Link Road Non-Public Water System Operation and Maintenance Manual (as part of Additional Investigation Plan)
Oct. 2013 BFI-VT submits copies of Water Supply Agreements recorded with landowner deeds to EPA (as part of the Additional Investigation Plan)
Nov. 2013 State of Vermont revised / expanded the extent of the groundwater reclassification area to correct for inaccurate boundaries included in the original 2008 reclassification petition (based on information provided by BFI-VT in November 2012). This was done to fulfill portions of the Additional Investigation Plan.
Mar. 2014 EPA issues comments on the August 2012 Vapor Intrusion Evaluation and requests a vapor intrusion investigation work plan be developed, and that a new Site specific Quality Assurance Project Plan (QAPP) be prepared for sampling activities being conducted in 2014 as part of the Five Year Review sampling requirements and soil vapor sampling activities.
June 2014 BFI-VT submits VI Work Plan and QAPP for 2014 5YR semi-annual sampling event and receives approval from EPA/VTDEC. Semi-Annual monitoring event is conducted in accordance with QAPP. Soil vapor/gas probes are installed and sampled in accordance with VI Work Plan.
June 2014 EPA and BFI-VT prepare draft ESD. EPA begins process of finalizing ESD. The ESD documents the following changes to the ROD: 1) Updates status of ICs pertaining to groundwater extraction activities and restrictions that have been implemented at the site; 2) Establishes lower standards for arsenic and lead pursuant to Safe Drinking Water Act; 3) Establishes a revised time-frame for restoration of bedrock groundwater.
July 2014 BFI-VT submits an Additional Investigations Plan Summary Report and Estimated Timeframe for the Restoration of Bedrock Groundwater, which provides a summary of the status of the additional investigation plan items and provides an estimated timeframe for the restoration of bedrock groundwater based on long-term monitoring from 1995 to 2013.
Sept 2014 Fourth Five-Year Review completed
September 2014
EPA completes Explanation of Significant Differences (ESD established a new estimated timeframe for groundwater restoration, revised the arsenic and lead IGCLs (based on changes to federal and state standards) and documented inclusion of additional institutional controls and VTDEC groundwater reclassification to prevent groundwater use at the site
April 2015
BFI-VT submits a Vapor Intrusion Investigation Summary Report to document the 2014 investigation with findings that subsurface vapor intrusion pathways did not pose an unacceptable vapor intrusion risk and that the water line was not providing a preferred vapor pathway
March 2016
2015-2018 Long Term Monitoring Plan Revision approved by EPA
September 2016
2016 Site Specific Quality Assurance Project Plan approved by EPA
April 2019 2019 Site Specific Quality Assurance Project Plan approved by EPA
APPENDIX F – PUBLIC NOTICE PRESS RELEASE
An official website of the United States government.
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News Releases from Region 01
EPA begins reviews of six Vermont Superfund site cleanups this year 02/21/2019
Contact Information: Emily Bender ([email protected]) 617-918-1037
Boston - The U.S. Environmental Protection Agency (EPA) plans to conduct comprehensive reviews of site cleanups at six National Priorities List (NPL) Superfund sites in Vermont by performing required Five-Year Reviews of sites.
"It is a priority for EPA to make progress cleaning up NPL Superfund sites across the region," said EPA New England Acting Regional Administrator Deb Szaro. "Once a site or part of a site is cleaned up, it is important for EPA to conduct regular reviews of the cleanup to ensure that it remains protective of human health and the environment."
"The Five-Year Reviews are an important part of the site rehabilitation process because they help make sure remedies are still protective," said Vermont Department of Environmental Conservation Commissioner Emily Boedecker. "Vermonters benefit greatly from the full restoration of Superfund sites, which can become valuable parts of the community landscape."
The Superfund program, a federal program established by Congress in 1980, investigates and cleans up the most complex, uncontrolled or abandoned hazardous waste sites in the country and endeavors to facilitate activities to return them to productive use.
Under the Trump Administration, the Superfund program has reemerged as a priority to fulfill EPA's core mission of protecting human health and the environment.
EPA is actively involved in Superfund studies and cleanups at 14 sites in Vermont. There are many phases of the Superfund cleanup process including considering future use and redevelopment at sites and conducting post-cleanup monitoring of sites. EPA must ensure remedies are protective of public health and the environment and any redevelopment will not compromise the protectiveness of completed remedies.
The NPL Superfund site where EPA will begin work on Five-Year Reviews in 2019 are listed below. Please note, the web links listed below provide detailed information on site status and past assessment and cleanup activity. Once the Five-Year Review is complete, a report of its findings will be posted to these websites. The web link also provides contact information for the EPA project manager and community involvement coordinator at each site. Community members and local officials are invited to contact EPA with any comments or concerns about a Superfund site.
Five-Year Reviews beginning in 2019
Bennington Municipal Sanitary Landfill, Bennington, V.T. www.epa.gov/superfund/bennington
BFI Sanitary Landfill, Rockingham, V.T. http://w,vw.epa.gov/superfund/bfi
Elizabeth Mine, Strafford, V.T. www.epa.gov/superfund/elizmine
Parker Sanitary Landfill, Lyndon, V.T. www.epa.gov/superfund/parker
Pownal Tannery, Pownal, V.T. http://www.epa.gov/superfund/pownal
Tansitor Electronics Inc., Bennington, V.T. www.epa.gov/superfund/tansitor
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In May 2017, EPA established a task force to restore the Superfund program to its rightful place at the center of the Agency's core mission to protect health and the environment.
LAST UPDATED ON FEBRUARY 21, 2019
APPENDIX G - INTERVIEW SUMMARY
INTERVIEW RECORD
Site Name: BFI Rockingham Landfill Superfund Site EPA ID No.: VTD980520092
Subject: Fifth Five-Year Review Time:1145 Date: June 12, 2019
Type: Telephone ■ Visit Other Location of Visit: Rockingham, Vermont
Incoming Outgoing
CONTACT MADE BY Name(s): Kevin Heine
Title(s): Project Mgr. Organization(s): US EPA Region 1
Additional Attendees: Roger Bellerose Michael Deyling
Titles(s): Site Contractor Sr. Project Geologist
Organization(s): BGEC, LLC CES, Inc.
INDIVIDUAL CONTACTED: Name: John Banholzer Title:17-year resident Organization: Town of
Rockingham Telephone No: Fax No: E-Mail Address:
Street Address: 14 Riverfront Drive City, State: Rockingham, Vermont
SUMMARY OF CONVERSATION
1) What is your familiarity with the Site? As a longtime town resident knew of the Site when it was in operation.
2) What effects have Site operations had on the surrounding community? None that John is aware of.
3) Are you aware of any community concerns regarding the Site or its operation and administration? Only concern is that it remains intact and stable, doesn’t want it to move down-slope.
4) Do you feel well informed about the Site’s activities and progress? Yes.
5) Would you like to see anything done differently at the Site?
No. The drinking water system seems more stable, pressures have increased.
6) Do you have any comments, suggestions, or recommendations regarding the Site’s management or operation? No, leave that up to Republic and its contractors.
INTERVIEW RECORD
Site Name: BFI Rockingham Landfill Superfund Site EPA ID No.: VTD980520092 Subject: Fifth Five-Year Review Time:1230 Date: June 12, 2019 Type: Telephone ■ Visit Other Location of Visit: Rockingham, Vermont
Incoming Outgoing
CONTACT MADE BY Name(s): Kevin Heine
Title(s): Project Manager Organization(s): US EPA Region 1
Additional Attendees: Roger Bellerose Michael Deyling
Titles(s): Site Contractor Sr. Project Geologist
Organization(s): BGEC, LLC CES, Inc.
INDIVIDUAL CONTACTED: Name: Wayne Johnson Title:64-year resident Organization: Town of
Rockingham Telephone No: Fax No: E-Mail Address:
Street Address: 12 Riverfront Drive City, State: Rockingham, Vermont
SUMMARY OF CONVERSATION
1) What is your familiarity with the Site? Grew up here, as a child the area was Wayne’s summer camp.
2) What effects have Site operations had on the surrounding community? No effects on the residents since the resident nearest the water extraction wells (Greenwood) moved; Wayne’s water pressure has been good.
3) Are you aware of any community concerns regarding the Site or its operation and administration? No.
4) Do you feel well informed about the Site’s activities and progress? Yes, knows who to contact if there are any issues.
5) Would you like to see anything done differently at the Site? No, if there’s ever a problem, Wayne knows how to contact Roger Bellerose.
6) Do you have any comments, suggestions, or recommendations regarding the Site’s management or operation? No, but Wayne does have a concern regarding surface drainage from Route 5 onto his driveway that he continues to monitor.
APPENDIX H –SITE INSPECTION CHECKLIST
Five-Year Review Site Inspection Checklist
“N/A” refers to “not applicable.”
I. SITE INFORMATION
Site name: BFI-Rockingham Landfill Date of inspection: June 12, 2019
Location and Region: Rockingham, Vermont EPA ID: VTD980520092
Agency, office, or company leading the five-year review: USEPA Region I
Weather/temperature: Sunny, 60s
Remedy Includes: (Check all that apply) X Landfill cover/containment X Monitored natural attenuation X Access controls □ Groundwater containment X Institutional controls □ Vertical barrier walls X Groundwater pump and off-site treatment □ Surface water collection and treatment □ Other______________________________________________________________________ _____________________________________________________________________________
Attachments: □ Inspection team roster attached □ Site map attached
II. INTERVIEWS (Check all that apply)
1. O&M site manager _Chris Ford________________ __BFI Project Manager__ __June 12, 2019____ Name Title Date
Interviewed X at site □ at office □ by phone Phone no. ______________ Problems, suggestions; □ Report attached ________________________________________________ __________________________________________________________________________________
2. O&M staff __Roger Bellerose Blue Granite Environmental_______________ June 12, 2019
Name Title Date Interviewed X at site □ at office □ by phone Phone no. ______________ Problems, suggestions; □ Report attached _______________________________________________ __________________________________________________________________________________
3. Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response office, police department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county offices, etc.) Fill in all that apply.
Agency USEPA_ Contact Kevin Heine Project Manager June 12, 2019
Name Title Date Phone no. Problems; suggestions; □ Report attached _______________________________________________ __________________________________________________________________________________
Agency VTDEC Contact Michael Smith __________________ ________ ____________
Name Title Date Phone no. Problems; suggestions; □ Report attached _______________________________________________ __________________________________________________________________________________
Agency ____________________________ Contact ____________________________ __________________ ________ ____________
Name Title Date Phone no. Problems; suggestions; □ Report attached _______________________________________________ __________________________________________________________________________________
Agency ____________________________ Contact ____________________________ __________________ ________ ____________
Name Title Date Phone no. Problems; suggestions; □ Report attached _______________________________________________ __________________________________________________________________________________
4. Other interviews (optional) X Report attached. See Appendix D of 2019 FYR
Local Residents Banholzer and Johnson from Riverview Lane (Missing Link Water Supply System users).
III. ON-SITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)
1. O&M Documents □ O&M manual □ Readily available □ Up to date □ N/A □ As-built drawings □ Readily available □ Up to date □ N/A □ Maintenance logs □ Readily available □ Up to date □ N/A Remarks__________________________________________________________________________ ____________________________________________________________________
2. Site-Specific Health and Safety Plan □ Readily available □ Up to date □ N/A □ Contingency plan/emergency response plan □ Readily available □ Up to date □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
3. O&M and OSHA Training Records □ Readily available □ Up to date □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
4. Permits and Service Agreements □ Air discharge permit X Readily available X Up to date □ N/A □ Effluent discharge □ Readily available □ Up to date X N/A X Waste disposal, POTW X Readily available X Up to date □ N/A □ Other permits_____________________ □ Readily available □ Up to date □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
5. Gas Generation Records X Readily available X Up to date □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
6. Settlement Monument Records □ Readily available □ Up to date X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
7. Groundwater Monitoring Records X Readily available X Up to date □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
8. Leachate Extraction Records X Readily available □ Up to date □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
9. Discharge Compliance Records □ Air □ Readily available X Up to date □ N/A □ Water (effluent) □ Readily available □ Up to date X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
10. Daily Access/Security Logs □ Readily available □ Up to date X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
IV. O&M COSTS
1. O&M Organization □ State in-house □ Contractor for State □ PRP in-house X Contractor for PRP □ Federal Facility in-house □ Contractor for Federal Facility □ Other__________________________________________________________________________
_________________________________________________________________________________
2. O&M Cost Records X Readily available □ Up to date X Funding mechanism/agreement in place Original O&M cost estimate: The original O&M cost prediction provided in the 1994 ROD for post closure
O&M for a period of 5 to 30 years after the completion of the NTCRA ranged from $90,000 to $200,000 per year.
Total annual cost by year for review period if available
From__2018____ To__________ $299,662__________ □ Breakdown attached Date Date Total cost
From__2017____ To__________ $310,594__________ □ Breakdown attached Date Date Total cost
From__2016____ To__________ $309,053__________ □ Breakdown attached Date Date Total cost
From__2015____ To__________ $370,805__________ □ Breakdown attached Date Date Total cost
From__2014____ To__________ $439,672__________ □ Breakdown attached Date Date Total cost
3. Unanticipated or Unusually High O&M Costs During Review Period Describe costs and reasons: _NA_________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________
V. ACCESS AND INSTITUTIONAL CONTROLS X Applicable □ N/A
A. Fencing
1. Fencing damaged □ Location shown on site map X Gates secured □ N/A Remarks_No fencing damage observed._____________________________________________ _________________________________________________________________________________
B. Other Access Restrictions
1. Signs and other security measures □ Location shown on site map □ N/A Remarks Signs and remote video observation in place. _________________________________________________________________________________
C. Institutional Controls (ICs)
1. Implementation and enforcement Site conditions imply ICs not properly implemented □ Yes X No □ N/A Site conditions imply ICs not being fully enforced □ Yes X No □ N/A
Type of monitoring (e.g., self-reporting, drive by) _________________________________________ Frequency ________________________________________________________________________ Responsible party/agency ____________________________________________________________ Contact ____________________________ __________________ ________ ____________
Name Title Date Phone no.
Reporting is up-to-date X Yes □ No □ N/A Reports are verified by the lead agency X Yes □ No □ N/A
Specific requirements in deed or decision documents have been met X Yes □ No □ N/A Violations have been reported □ Yes X No □ N/A Other problems or suggestions: □ Report attached _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________
2. Adequacy X ICs are adequate □ ICs are inadequate □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________
D. General
1. Vandalism/trespassing □ Location shown on site map X No vandalism evident Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Land use changes on site X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Land use changes off site X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
VI. GENERAL SITE CONDITIONS
A. Roads X Applicable □ N/A
1. Roads damaged □ Location shown on site map X Roads adequate □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
B. Other Site Conditions
Remarks ______________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________
____________________________________________________________________
VII. LANDFILL COVERS X Applicable □ N/A
A. Landfill Surface
1. Settlement (Low spots) X Location shown on site map □ Settlement not evident Areal extent______________ Depth____________ Remarks Depressions in the cap surface continue to be observed throughout the landfill, particularly in the vicinity of gas extraction vents. Low spots observed during the 2013 – 2018 inspection are still present in the vicinity of EW-25, EW-36, and EW-33/34. Additional low spots were observed in the vicinity of EW-27 and EW-37. Depressions remain minor and do not appear to pose a threat to the integrity of the cap.
2. Cracks □ Location shown on site map X Cracking not evident Lengths____________ Widths___________ Depths__________ Remarks____________________________________________________________ __________________________________________________________________
3. Erosion □ Location shown on site map X Erosion not evident Areal extent______________ Depth____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
4. Holes □ Location shown on site map X Holes not evident Areal extent______________ Depth____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
5. Vegetative Cover X Grass X Cover properly established X No signs of stress □ Trees/Shrubs (indicate size and locations on a diagram) Remarks__________________________________________________________________________ _________________________________________________________________________________
6. Alternative Cover (armored rock, concrete, etc.) X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
7. Bulges □ Location shown on site map X Bulges not evident Areal extent______________ Height____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
8. Wet Areas/Water Damage X Wet areas/water damage not evident □ Wet areas □ Location shown on site map Areal extent______________ □ Ponding □ Location shown on site map Areal extent______________ □ Seeps □ Location shown on site map Areal extent______________ □ Soft subgrade □ Location shown on site map Areal extent______________ Remarks__________________________________________________________________________ _________________________________________________________________________________
9. Slope Instability □ Slides □ Location shown on site map X No evidence of slope instability Areal extent______________ Remarks__________________________________________________________________________ _________________________________________________________________________________
B. Benches X Applicable □ N/A (Horizontally constructed mounds of earth placed across a steep landfill side slope to interrupt the slope in order to slow down the velocity of surface runoff and intercept and convey the runoff to a lined channel.)
1. Flows Bypass Bench □ Location shown on site map X N/A or okay Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Bench Breached □ Location shown on site map X N/A or okay Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Bench Overtopped □ Location shown on site map X N/A or okay Remarks__________________________________________________________________________ _________________________________________________________________________________
C. Letdown Channels X Applicable □ N/A (Channel lined with erosion control mats, riprap, grout bags, or gabions that descend down the steep side slope of the cover and will allow the runoff water collected by the benches to move off of the landfill cover without creating erosion gullies.)
1. Settlement □ Location shown on site map X No evidence of settlement Areal extent______________ Depth____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Material Degradation □ Location shown on site map X No evidence of degradation Material type_______________ Areal extent_____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Erosion □ Location shown on site map X No evidence of erosion Areal extent______________ Depth____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
4. Undercutting □ Location shown on site map X No evidence of undercutting Areal extent______________ Depth____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
5. Obstructions Type_____________________ X No obstructions □ Location shown on site map Areal extent______________ Size____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
6. Excessive Vegetative Growth Type____________________ □ No evidence of excessive growth □ Vegetation in channels does not obstruct flow □ Location shown on site map Areal extent______________ Remarks Vegetation observed during Fall 2018 inspection had been removed prior to Spring 2019 inspection
D. Cover Penetrations X Applicable □ N/A
1. Gas Vents X Active □ Passive □ Properly secured/locked □ Functioning □ Routinely sampled X Good condition □ Evidence of leakage at penetration □ Needs Maintenance □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Gas Monitoring Probes X Properly secured/locked □ Functioning □ Routinely sampled □ Good condition □ Evidence of leakage at penetration □ Needs Maintenance □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Monitoring Wells (within surface area of landfill) X Properly secured/locked □ Functioning □ Routinely sampled □ Good condition □ Evidence of leakage at penetration □ Needs Maintenance □ N/A
Remarks___________________________________________________________ _________________________________________________________________
4. Leachate Extraction Wells □ Properly secured/locked □ Functioning □ Routinely sampled □ Good condition □ Evidence of leakage at penetration □ Needs Maintenance X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
5. Settlement Monuments □ Located □ Routinely surveyed X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
NOT FOR
CONSTRUCTION
FOR REVIEW
Engineers Environmental Scientists Surveyors
BFI-ROCKINGHAM LANDFILL SUPERFUND SITE
ROCKINGHAM, VERMONT
SITE PLAN
2019 FIVE YEAR REVIEW INSPECTION
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E. Gas Collection and Treatment X Applicable □ N/A
1. Gas Treatment Facilities X Flaring □ Thermal destruction □ Collection for reuse □ Good condition □ Needs Maintenance Remarks_New Candlestick flare added date unknown
2. Gas Collection Wells, Manifolds and Piping X Good condition □ Needs Maintenance Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Gas Monitoring Facilities (e.g., gas monitoring of adjacent homes or buildings) □ Good condition □ Needs Maintenance X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
F. Cover Drainage Layer X Applicable □ N/A
1. Outlet Pipes Inspected X Functioning □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Outlet Rock Inspected X Functioning □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
G. Detention/Sedimentation Ponds X Applicable □ N/A
1. Siltation Areal extent______________ Depth____________ □ N/A X Siltation not evident Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Erosion Areal extent______________ Depth____________ X Erosion not evident Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Outlet Works X Functioning □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
4. Dam □ Functioning X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
H. Retaining Walls X Applicable □ N/A
1. Deformations □ Location shown on site map X Deformation not evident Horizontal displacement____________ Vertical displacement_______________ Rotational displacement____________ Remarks__________________________________________________________________________
_________________________________________________________________________________
2. Degradation □ Location shown on site map X Degradation not evident Remarks__________________________________________________________________________ _________________________________________________________________________________
I. Perimeter Ditches/Off-Site Discharge X Applicable □ N/A
1. Siltation □ Location shown on site map X Siltation not evident Areal extent______________ Depth____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Vegetative Growth □ Location shown on site map □ N/A X Vegetation does not impede flow Areal extent______________ Type____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Erosion □ Location shown on site map X Erosion not evident Areal extent______________ Depth____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
4. Discharge Structure □ Functioning X N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
VIII. VERTICAL BARRIER WALLS □ Applicable X N/A
1. Settlement □ Location shown on site map □ Settlement not evident Areal extent______________ Depth____________ Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Performance Monitoring Type of monitoring__________________________ □ Performance not monitored Frequency_______________________________ □ Evidence of breaching Head differential__________________________ Remarks__________________________________________________________________________ _________________________________________________________________________________
IX. GROUNDWATER/SURFACE WATER REMEDIES X Applicable □ N/A
A. Groundwater Extraction Wells, Pumps, and Pipelines □ Applicable □ N/A
1. Pumps, Wellhead Plumbing, and Electrical X Good condition □ All required wells properly operating □ Needs Maintenance □ N/A Remarks Route 6 Seepage and Drainage Control Structure pumps to AST for off-site disposal
2. Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances X Good condition □ Needs Maintenance Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Spare Parts and Equipment X Readily available □ Good condition □ Requires upgrade □ Needs to be provided Remarks__________________________________________________________________________ _________________________________________________________________________________
B. Surface Water Collection Structures, Pumps, and Pipelines □ Applicable □ N/A
1. Collection Structures, Pumps, and Electrical X Good condition □ Needs Maintenance Remarks Tire chip drainage layer and northwest retention pond _
2. Surface Water Collection System Pipelines, Valves, Valve Boxes, and Other Appurtenances X Good condition □ Needs Maintenance Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Spare Parts and Equipment X Readily available □ Good condition □ Requires upgrade □ Needs to be provided Remarks__________________________________________________________________________ _________________________________________________________________________________
C. Treatment System □ Applicable X N/A
1. Treatment Train (Check components that apply) □ Metals removal □ Oil/water separation □ Bioremediation □ Air stripping □ Carbon adsorbers □ Filters_________________________________________________________________________ □ Additive (e.g., chelation agent, flocculent)_____________________________________________ □ Others_________________________________________________________________________ □ Good condition □ Needs Maintenance □ Sampling ports properly marked and functional □ Sampling/maintenance log displayed and up to date □ Equipment properly identified □ Quantity of groundwater treated annually________________________ □ Quantity of surface water treated annually________________________ Remarks__________________________________________________________________________ _________________________________________________________________________________
2. Electrical Enclosures and Panels (properly rated and functional) □ N/A □ Good condition □ Needs Maintenance Remarks__________________________________________________________________________ _________________________________________________________________________________
3. Tanks, Vaults, Storage Vessels □ N/A □ Good condition □ Proper secondary containment □ Needs Maintenance Remarks__________________________________________________________________________ _________________________________________________________________________________
4. Discharge Structure and Appurtenances □ N/A □ Good condition □ Needs Maintenance Remarks__________________________________________________________________________ _________________________________________________________________________________
5. Treatment Building(s) □ N/A □ Good condition (esp. roof and doorways) □ Needs repair □ Chemicals and equipment properly stored Remarks__________________________________________________________________________ _________________________________________________________________________________
6. Monitoring Wells (pump and treatment remedy) □ Properly secured/locked □ Functioning □ Routinely sampled □ Good condition □ All required wells located □ Needs Maintenance □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
D. Monitoring Data
1. Monitoring Data X Is routinely submitted on time □ Is of acceptable quality
2. Monitoring data suggests: □ Groundwater plume is effectively contained X Contaminant concentrations are declining
D. Monitored Natural Attenuation
1. Monitoring Wells (natural attenuation remedy) X Properly secured/locked X Functioning X Routinely sampled □ Good condition X All required wells located □ Needs Maintenance □ N/A Remarks__________________________________________________________________________ _________________________________________________________________________________
X. OTHER REMEDIES If there are remedies applied at the site which are not covered above, attach an inspection sheet describing the physical nature and condition of any facility associated with the remedy. An example would be soil vapor extraction.
XI. OVERALL OBSERVATIONS
A. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief statement of what the remedy is to accomplish (i.e., to contain contaminant plume, minimize infiltration and gas emission, etc.). ____________________________________________________________________
____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________
B. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their relationship to the current and long-term protectiveness of the remedy. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________
C. Early Indicators of Potential Remedy Problems
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of unscheduled repairs, that suggest that the protectiveness of the remedy may be compromised in the future. _NA________________________________________________________________
____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________
VIII.A.1 D. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________
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