voluntary cleanup program response action plan · august 20, 2016 the prp group submitted a...

180228 CES Griggs Road RAP.doc

VOLUNTARY CLEANUP PROGRAM RESPONSE ACTION PLAN

for

CES GRIGGS ROAD VCP SITE

VCP 2751 CN604824904 RN108370644

CES ENVIRONMENTAL SERVICES 4904 GRIGGS ROAD

HOUSTON, TEXAS 77021

Prepared by:

PASTOR, BEHLING, & WHEELER, LLC

11231 Richmond Avenue, D104 Houston, Texas Project No. 4020

March 2017

RAP Executive Summary ID No.: VCP 2751 Report Date: March 7, 2018

180307 CES Griggs Road RAP.doc 2

Use this worksheet to summarize the report. Be sure to complete and submit the Checklist for Report Completeness. Attach a chronology of activities associated with the affected property. Briefly describe the affected property and PCLE zones, the conclusions from the assessment activities, identify any affected or threatened receptors, and describe any other major considerations taken into account when developing this response action plan. If any portion of the response action is necessitated due to an aesthetic or nuisance condition, identify the nature of that condition and identify that portion of the response action proposed to address it. If any media that contains a PCLE zone is not addressed in this RAP, provide justification. This Response Action Plan (RAP) addresses the concentrations of chlorinated volatile organic compounds (CVOCs), total petroleum hydrocarbons (TPH), manganese, and vanadium that exceed the critical protective concentration levels (PCLs) at the CES Griggs Road VCP Site located at 4904 Griggs Road and 5910 Wayland Street in Houston, Harris County, Texas (the “Site”). The Site is a former industrial cleaning, waste recycling, and waste disposal facility owned by CES Environmental Services (CES) but currently under the control of a Chapter 7 Bankruptcy Trustee. Past and current land use for the Site is commercial/industrial and future anticipated land usage is also commercial/industrial. The Younger family purchased the 4904 Griggs Road property in the early 1940’s and built/operated a tank truck terminal (WCM, 1996). Operations included dispatch, storage, routine maintenance, and internal and external washing of tank trucks that hauled a variety of petrochemical substances. CES purchased this property in June 2002 and operated the facility as an industrial and hazardous waste treatment facility until bankruptcy in August 2010. CES cleaned truck trailers, roll-off boxes, totes and other transportation equipment. Materials within the equipment included petroleum products, paint thinners, solvents, and acids. CES also recycled motor oil and solvents such as acetone, methyl ethyl ketone, and methylene chloride. The company processed sodium sulfide, sodium hydroxide, and naphthenic acid solutions and treated industrial wastewater at the Site (TCEQ, 2015). CES purchased the 5910 Wayland Street and 4900 Griggs Road properties in 2006. The 4900 Griggs Road property was acquired for use as an employee parking lot for the facility. Between 2005 and 2009, the City of Houston responded to odor and emission complaints by nearby residents (TCEQ, 2015). Several incidents occurred at the Site in 2014, which resulted in the release of waste materials (TCEQ, 2015). Response actions were conducted by the City of Houston, the Texas Commission on Environmental Quality (TCEQ), and the United States Environmental Protection Agency (EPA). These response actions included the removal and disposal of the off-Site waste, flushing the storm sewers, removing oily materials from the ponded areas on-Site, the construction of physical controls to prevent off-Site releases, and the repair of the security fence. The CES Griggs Road Potentially Responsible Party (PRP) Group (the “PRP Group”) will close the waste management units in accordance with the Texas Risk Reduction Program (TRRP) requirements in RG-366/TRRP-2A (Closure of Waste Management Units Subject to TRRP (July 2011)). In June 2015, the Site was accepted into the TCEQ VCP and the PRP Group initiated the affected property assessment. Soil impacts are delineated to the residential assessment level (RAL). No affected property was identified for the 4900 Griggs Road portion of the Site. Analytical data indicate that manganese and vanadium concentrations within the City of Houston right-of-way at 5910 Wayland Street exceed the RAL. A critical Protective Concentration Level exceedance (PCLE) zone for a commercial/industrial site is identified for TPH (C6 – nC12) in surface soil in the southern part of 4904 Griggs Road. The affected properties and critical PCLE zones for the soil media are shown on Attachment 1A-1. Groundwater assessment activities included the installation of eight monitoring wells and analyses for volatile organic compounds (VOCs), TPH, semivolatile organic compounds (SVOCs), and metals (manganese, vanadium, and barium). Analytical data indicate that concentrations of the chlorinated volatile organic compounds (CVOCs), tetrachloroethene, trichloroethene, cis-1,2-dichloroethene, and vinyl chloride, slightly exceed their respective critical PCLs on the 4904 Griggs Road portion of the Site. Groundwater impacts from CVOCs released from Site historical operations are limited to the Site property. The extent of the CVOC affected property on-Site is delineated on-Site using data from the temporary wells TMW-02, TMW-03, and TMW-04 installed in January 2018. The affected property and



critical PCLE zone for the groundwater media are shown on Attachment 1A-1. The final Affected Property Assessment Report (APAR) was submitted to TCEQ on April 18, 2017 and approved on November 7, 2017 (CES, 2017a; TCEQ, 2017b). The TCEQ requested a submittal of this RAP in the APAR approval letter. The proposed residential soil response action relies on excavation and disposal to mitigate potential human exposure to manganese and vanadium at concentrations exceeding the TotSoilComb PCLs at 5910 Wayland Street. Groundwater monitoring is the proposed response action to monitor leaching of TPH from soil-to-groundwater at concentrations exceeding the GWSoilIng PCL at 4904 Griggs Road. A plume management zone (PMZ) with evaluation of natural attenuation of CVOCs and institutional controls are the proposed response actions for the groundwater CVOC PCLE zone at 4904 Griggs Road In addition to the response actions discussed above, the Bankruptcy Trustee will deed record the affected property prohibiting groundwater usage and restricting the property to commercial / industrial land use. What is the selected remedy standard for this affected property? X A X B List all media that contains a PCLE zone and specify the proposed response action for each media. Indicate the type of removal, decontamination, physical control and/or institutional control action that is proposed.

Media COCs1 Removal Decontamination Control Physical Control

Modified Groundwater Response Objective2

PMZ WCU TI

Soil Manganese, Vanadium X

Soil TPH X Groundwater CVOCs X

Is there a media that contains a PCLE zone that is not addressed in this RAP? yes X noIf yes, provide justification for not addressing the PCLE zone in this RAP.

On-site land use: Residential X Commercial/IndustrialOff-site land use: X Residential Commercial/Industrial (check all that apply)

Is this a re-submittal or revision of a previous RAP? Yes X NoIf yes, explain why the RAP is being revised or resubmitted. Not applicable

Were all the appropriate notifications made in accordance with §350.55? X Yes NoIf no, explain why notifications were not made:Not applicable

1 Specify either a specific COC or, if the response action is the same for all COCs in one type, specify the type of COC (for example, VOCs, SVOCs, metals). 2 If a modified groundwater response objective is proposed, check the type(s) of proposed modifications.



Chronology CES Griggs Road VCP Site

Houston, Harris County, Texas This section is a summary of abatement, assessment, and remedial activities conducted at the affected property listed in chronological order beginning with the most recent activity. The date of actions taken and a brief description of release abatement activities, assessment activities, and response actions conducted are presented below.

Date(s) of Activity Description of Activity March 7, 2018 The PRP Group submitted the RAP to the TCEQ. January 18-19, 2018 Installed temporary wells on-Site (TMW-02 to TMW-04) and Grace Lane (TWGW-01 to TWGW-

03) and collected groundwater samples CVOC analyses. Collected six subsurface soil samples for pre-confirmation excavation delineation. Samples were analyzed for manganese and vanadium.

November 7, 2017 TCEQ approved the revised APAR. November 7, 2017 Collected and analyzed groundwater samples from monitor wells MW-01 through MW-08 for

CVOCs. Analyzed groundwater from MW-03 for dibenz(a,h)anthracene. Analyzed groundwater from MW-04 and MW-08 for TPH.

October 16, 2017 Submitted response letter with second transmissive zone data to the TCEQ. October 11, 2017 Submitted response letter with revisions to Section 4 and 11 to develop residential critical PCLs

for manganese and vanadium in the City of Houston right-of-way at 5910 Wayland Street. October 10, 2017 Collected and analyzed groundwater samples from second transmissive zone temporary well

CPT-7-2 for CVOCs. October 6, 2017 Submitted laboratory reports and data usability summaries (DUS) for February, May, and

August 2017 sampling events to the TCEQ. September 21, 2017 Submitted groundwater gauging event data from July 26, 2017 and groundwater analytical

results from the February, May, and August 2017 sampling events to the TCEQ. August 10, 2017 Collected and analyzed groundwater samples from monitor wells MW-01 through MW-08 for

CVOCs. Analyzed groundwater from MW-03 for dibenz(a,h)anthracene. July 26, 2017 Gauged monitoring wells located at the Site and the Former Joy Tabernacle VCP 2729 site to

assess groundwater gradients in the area. May 31 to July 18, 2017 Implemented waste closure activities for container storage areas, tanks and sumps. May 16, 2017 Collected and analyzed groundwater samples from monitor wells MW-01 through MW-08 for

CVOCs. April 18, 2017 The PRP Group submitted the revised APAR to the TCEQ. February 1, 2017 The PRP Group received TCEQ approval to proceed with the waste unit closures. January 24 – March 7, 2017

Phase III Investigation: Six cone penetrometer test (CPT) locations were installed on 4904 Griggs Road to

evaluate the depth to and thickness of the clay aquitard between the transmissive zones.

Installed one soil boring on 4904 Griggs Road (4904-SB31). One soil sample was collected and analyzed for manganese for lateral delineation.

Installed five soil borings on 5910 Wayland Street (5910-HA01 through 5910-HA05). Soil samples were collected from each boring and analyzed for vanadium manganese, and benzo(a)pyrene as needed for lateral and vertical delineation.

Installed one monitoring well (MW-06) for delineation of the CVOC plume. Installed two monitoring wells (MW-07 and MW-08) to evaluate potential impacts from

TPH to groundwater. Collected and analyzed groundwater samples from monitor wells MW-01 through MW-

08 for CVOCs, TPH, 1-methylnaphthalene, and selected metals. Collected and analyzed confirmation groundwater samples from MW-01, MW-05, and

MW-06 for CVOCs. November 30, 2016 TCEQ provided concurrence with the PRP Group Response to Comments Letter dated August

20, 2016.



Date(s) of Activity Description of Activity September 30, 2016 The PRP Group submitted the Waste Unit Closure Plan. August 20, 2016 The PRP Group submitted a response to comments on the APAR to TCEQ. June 24, 2016 TCEQ response letter to APAR submittal. June 7, 2016 Collected and analyzed groundwater samples from monitor wells MW-01 through MW-05 for

CVOCs. March 31, 2016 The PRP Group submitted the APAR to the TCEQ. January 4, 2016 Phase II Investigation:

Installed nine soil borings on 4904 Griggs Road (4904-SB02A, 4904SB02B, 4904-SB24 through 4904-SB30). Soil samples were collected from each boring and analyzed for selected metals, VOCs, and TPH, as needed for delineation.

Installed 14 soil borings on 5910 Wayland Street (5910-SB03A, 5910-SB04A, 5910-SB07 through 5910SB18). Soil samples were collected from each boring and analyzed for selected metals as needed for delineation.

Installed five shallow monitoring wells (MW-01 to MW-05) for the assessment and delineation of CVOCs.

Collected and analyzed groundwater samples from monitor wells MW-01 through MW-05 for CVOCs.

December 22, 2015 The PRP Group performed Drinking Water Survey. October 27, 2015 TCEQ approved the Historic Report Summary for the 5910 Wayland Site. September 23, 2015 The PRP Group submitted the Historic Report Summary for the 5910 Wayland Site to the

TCEQ. September 16-23, 2015 Phase I Investigation:

Installed three soil borings on 4900 Griggs Road (4900-SB01 through 4900-SB03). Three soil samples were collected from each boring and analyzed for metals, SVOCs, TPH, and VOCs.

Installed 23 soil borings on 4904 Griggs Road (4904-SB01 through 4904-SB23). Three soil samples were collected from each boring and analyzed for metals, SVOCs, TPH, and VOCs.

Installed six soil borings on 5910 Wayland Street (5910-SB-01 through 5910-SB-06). Three soil samples were collected from each boring and analyzed for metals, SVOCs, TPH, and VOCs.

June 10, 2015 TCEQ approved the VCP application and the Site was accepted into the VCP. May 15, 2015 The PRP Group submitted the VCP application to the TCEQ. August 2014 EPA collected nine surface soil samples from residential yards along Kingsbury Street south of

the Site following the storm water release from the Site (EPA, 2017). Samples were analyzed for herbicides, pesticides, polychlorinated biphenyls (PCBs), SVOCs, metals, TPH, and VOCs.

August 2014 EPA and their emergency response contractor mobilized to initiate the removal and disposal of hazardous wastes and substances contained in approximately 22 above-ground storage tanks (ASTs), two roll-off boxes, 12 frac tanks, 11 vacuum boxes, two tanker trailers, 224 totes/drums, and other containers located at the Site.

Late July and early August 2014

Vandals removed portions of the security fence and opened a valve on a tanker truck trailer, releasing the contents of the tanker. A second off-Site release occurred after a heavy rainfall. Response actions were conducted by the City of Houston, the TCEQ’s emergency response contractor, and EPA. These response actions included the removal and disposal of the off-Site material, the construction of physical controls to prevent off-site releases, and the repair of the security fence.

May 2014 Vandals damaged the security fence and emptied several containers onto the ground. Subsequently, heavy rainfall resulted in the release of material to off-Site areas. The Bankruptcy Trustee constructed a berm in the low-lying areas of the Site to prevent further off-Site releases and repaired leaking containers.

January 2014 The Bankruptcy Trustee collected four surface soil (0- to 1-feet below ground surface [bgs]) samples from the North and South Tank Farms. Samples were analyzed for Resource Conservation and Recovery Act (RCRA) metals, SVOCs, and VOCs.

December 2010 TGE Resources, Inc. (TGE) conducted a Phase II Environmental Site Assessment (ESA) at the former Holiday Townhomes property, located immediately west of the Site (TGE, 2011). Three



Date(s) of Activity Description of Activity soil borings were advanced to 36 feet bgs and temporary wells were installed in the borings. Two of the borings were installed adjacent to the CES property fence line. One soil sample and one groundwater sample were collected from each soil boring; samples were analyzed for RCRA metals, SVOCs, and VOCs.

August / October 2010 On August 13, 2010, CES filed for Chapter 11 bankruptcy and operations at the Site appear to have ceased at that time. On October 13, 2010, the bankruptcy case was converted to a Chapter 7 liquidation proceeding.

July 2010 Enercon Services conducted a Phase II ESA to evaluate property conditions for Bank of America (Enercon, 2010). Thirteen soil borings were advanced to a depth of 20 feet bgs. Soil samples were analyzed for VOCs, SVOCs, TPH, and RCRA metals. A temporary monitoring well was installed at SB-2.

October 2009 TCEQ collected eight surface soil samples (0 to 6-inches) around the perimeter of the Site. Samples were analyzed for VOCs, SVOCs, and metals.

September 1996 A Phase I and limited Phase II ESA was conducted on the Site when it was owned by Younger Brothers and operated as a truck terminal (WCM, 1996). Eleven borings were advanced in various locations throughout the Site, including near the underground storage tank (UST), the cleaning racks, a hazardous waste storage trailer, and near the location of the backfilled gully. Soil samples collected near the UST (SB-1 and SB-2) were analyzed for TPH and BTEX. Soil boring SB-1 was converted into a temporary monitoring well. Other soil samples were analyzed for TPH, VOCs, and SVOCs. Two grab samples were collected from soil piles along the Wayland Street right of way.

Checklist for Report Completeness ID No.: VCP 2751 Report Date: March 7, 2018


Use this checklist to determine the portions of the form that must be submitted for this report. Answer all questions by checking Yes or No. If the answer is Yes include that portion of the report. If the answer is No, do not complete or submit that portion of the report. All form contents that are marked "Required" must be submitted. Form contents marked with an asterisk (*) are not included in the blank form and are to be provided by the person. Report

Contents

Required Cover Page

Required Executive Summary

Required Checklist for Report Completeness

Required Worksheet 1.0 Response Action Objectives

No Have new data been collected that was not previously submitted?

Yes Attachment 1A* Maps and Cross Sections

Attachment 1B* Graphs of Concentration versus

Time

Required Worksheet 2.0 Response Action Design

Required Attachment 2A* Response Action Diagrams and

Component/Equipment Descriptions

Required Attachment 2B* Proposed Well Design

No Is an ecological services analysis or compensatory restoration plan part of the proposed response action?

Yes Attachment 2C* ESA and Compensatory

Restoration Plan

No Is a plume management zone proposed as part of the response action?

Yes Worksheet 2.1 Plume Management Zone

Attachment 2D* Plume Management Zone Map

Attachment 2E* Attenuation Action Levels

Determination

No Is a waste control unit proposed as part of the response action?

Yes Worksheet 2.2 Waste Control Unit

Attachment 2F* Map of Waste Control Unit

No Is a technical impracticability area proposed as part of the response action?

Yes Worksheet 2.3 Technical Impracticability

Attachment 2G* Map of Technical

Impracticability Area

Checklist for Report Completeness ID No.: VCP 2751 Report Date: March 7, 2018


Report Contents No Is the response action a remedy standard B? Yes Worksheet 2.4

Institutional Controls

Required Worksheet 3.0 Performance Measures and

Potential Problems

Required Worksheet 3.1 Monitoring and Sampling

Required Attachment 3A* Map of Monitoring and Sampling

Points

Required Worksheet 3.2 Operation and Maintenance

Required Worksheet 4.0 Confirmation Sampling Plan

Required Attachment 4A* Map of Confirmation Sampling

Points

No Is the response action a Remedy Standard B? Yes Worksheet 5.0 Post Response Action Care

Attachment 5A* Map of PRAC Monitoring and

Sampling Points

Attachment 5B* PRAC Costs

No Does the person, who is a small business, desire to modify the financial assurance requirement?

Yes Attachment 5C* Small Business Affidavit

Required Worksheet 6.0 Implementation Schedule

Required Appendix 1* References

No Was any data collected that was not previously reported?

Yes Appendix 2* Data Tables and Boring Logs

No Were any studies or tests conducted? Yes Appendix 3* Studies and Tests

Documentation

No Is the response action a Remedy Standard B? Yes Appendix 4* Proposed Institutional Controls

No Are any institutional controls proposed/required on property not owned by the person?

Yes Appendix 5* Landowner Concurrence

No Are any of the sample collection or handling procedures different from those reporting in the APAR

or other previously submitted report?

Yes Appendix 6* Sampling Procedures

No Are statistics or geostatistics proposed to be used as part of the response action?

Yes Appendix 7* Statistical Methodology

No Was approval received from the TCEQ regarding the use of different rules to address a media?

Yes Appendix 8* Split Media Approval

Form contents marked with an asterisk (*) are not included in the blank form.

Response Action Objectives Associated Information: Attachment 1A, 1B

RAP Worksheet 1.0 Page 8 of 29 ID No.: VCP 2751 Report Date: March 7, 2018


Use this worksheet to describe the objectives for the response action in each media. Response Action Objectives List the environmental media to which this applies Residential Soil – Manganese and VanadiumRepeat this section for each medium that has a different response action objective. State the property-specific response objectives for the PCLE zone in each media in the context of the response objectives set forth in §350.32 or §350.33 as applicable. Explain how the response action is appropriate based on the hydrogeologic characteristics, COC characteristics, and potential unprotective conditions that could continue or result during the remedial period. Residential Soil PCLE Zone: The response action objectives are based on excavation and off-Site disposal of near surface soil to prevent potential exposure to chemicals of concern (COCs) (30 TAC 350.4(a)(18)). The objective is to mitigate potential human exposure to manganese and vanadium concentrations exceeding the residential critical PCLs (TotSoilComb). Attachment 1A-1 shows the extent of the residential surface soil PCLE zone. Appendix 2-1 contains the pre-confirmation sampling data. Attachments 1A-2 and 1A-3 show the manganese and vanadium concentrations, respectively, in the critical PCLE zone. The residential soil PCLE zone is located within the City of Houston right-of-way adjacent to 5910 Wayland Street. The excavation and disposal of affected soil will remove potential unprotective concentrations of manganese and vanadium. The remedial period is short-term (days) and unprotective conditions should not result during the remedial period. Currently, this section of Wayland Street is fenced to prevent trespassing onto the Site. The fence will remain in place during the remedial action to prevent potential exposure to area residents. Response Action: Therefore, in accordance with 30 TAC §350.33(a)(1), the use of excavation/disposal at the off-Site property addresses Remedy Standard A response action objectives. Explain how the COCs will be handled, treated, disposed, or transferred to another media and document that the response action will not result in any additional potential exposure conditions due to response action activities. Residential Soil PCLE Zone: During the excavation/disposal, soils will be transported to a TCEQ-permitted disposal facility suitable for the waste classification of the soils. State the proposed “reasonable time frame” and provide the justification for that time frame in the context of any potential for unprotective exposures to exist or develop, COC characteristics, hydrogeologic and affected property characteristics. If the reasonable time frame is different for the different affected media or for particular tracts of land, be sure to discuss that. Provide how the proposed response action will meet the objectives in a reasonable timeframe. Residential Soil PCLE Zone: The remedy will provide future protection for potential residential receptors from exposure to manganese and vanadium at concentrations greater than the critical soil PCLs for the residential TotSoilComb exposure pathway. Excavation and disposal remedies are readily implemented and do not require engineering design or construction. The excavation and disposal will be implemented in accordance with the schedule provided on Worksheet 6.0. The response action for soils will be completed within the reasonable time frame as described in Worksheet 6.0. Response Action Objectives List the environmental media to which this applies Commercial/Industrial (C/I) Soil – TPH Repeat this section for each medium that has a different response action objective.




State the property-specific response objectives for the PCLE zone in each media in the context of the response objectives set forth in §350.32 or §350.33 as applicable. Explain how the response action is appropriate based on the hydrogeologic characteristics, COC characteristics, and potential unprotective conditions that could continue or result during the remedial period. Commercial /Industrial (C/I) Soil PCLE Zone: The objective of the Remedy Standard B response action is to mitigate potential human exposure to TPH leaching from soil to groundwater at concentrations exceeding the GWGWIng PCLs. The maximum concentration of 1,600 milligram/kilogram (mg/kg) for TPH (C6 – nC12) in 4904-SB15 (0 – 2 feet below ground surface [bgs]) exceeded the 0.5-acre commercial/industrial critical PCL of 650 mg/kg. Attachment 1A-1 shows the extent of the C/I soil critical PCLE zone. The C/I soil PCLE zone is located completely within the Site boundaries. Soil TPH concentrations are at the residential PCL for the TotSoilComb exposure pathway of 1,600 mg/kg. There is limited potential for risk to a commercial/industrial worker if exposed to the surface soils since the maximum concentration of 1,600 mg/kg is below the commercial/industrial TotSoilComb PCL of 3,900 mg/kg. TPH has not been detected in groundwater samples collected from Site monitoring wells in the May and November 2017 sample events. Appendix 2-2 and Attachment 1A-4 provide the Site groundwater data through November 2017. Appendix 2 also contains the November 2017 laboratory report. Soil TPH concentrations are below residual saturation; light non-aqueous phase liquids (LNAPL) has not been observed at the Site in soil borings or monitoring wells. Based on the following lines of evidence, groundwater monitoring is recommended for this COC. First, the emergency response action conducted by EPA and TCEQ in 2014/2015 removed the oily material deposited by vandals in the south tank farm containment area. The amount of time oily material was in the containment area was minimized by prompt agency responses to the vandalism. Additional response actions by the PRP Group were conducted in June and July 2017 to remove residual hydrocarbon materials from the south tank farm tanks and containment. Second, the source area is likely to be smaller than the 0.5-acre source depicted on Attachment 1A-1. TPH was not detected in the four samples (4904-SB12 to 4904-SB18) within 50 feet of the boring with a concentration exceeding the GWSoilIng PCL (4904-SB15). This indicates that the source area is approximately 2,500 square feet or 0.06-acre. Third, the maximum depth of the TPH (C6 – nC12) detection was 5 - 6 feet bgs in 4904-SB15. Fourth, TPH was not detected in the groundwater samples collected from MW-08 (Attachment 1A-4; Appendix 2-2), installed downgradient of the south tank farm, demonstrating that these hydrocarbons are not leaching to groundwater. The 1) previous removal action; 2) limited potential for unprotective human or ecological exposure at this affected property to TPH; 3) the apparent immobility of the TPH based on groundwater monitoring data and 4) the exposure pathway which requires the response action, the GWSoilIng, make the use of groundwater monitoring, decontamination, and institutional controls prohibiting groundwater usage a viable and preferable remedy for the surface soil PCLE zone. Response Action: Therefore, in accordance with 30 TAC §350.33(a)(1), the use of groundwater monitoring and institutional controls at the Site addresses the response action objectives. Explain how the COCs will be handled, treated, disposed, or transferred to another media and document that the response action will not result in any additional potential exposure conditions due to response action activities. Commercial /Industrial Soil PCLE Zone: Groundwater monitoring will not involve any potential exposure through treatment, disposal or transfer to another media. State the proposed “reasonable time frame” and provide the justification for that time frame in the context of any potential for unprotective exposures to exist or develop, COC characteristics, hydrogeologic and affected property characteristics. If the reasonable time frame is different for the different affected media or for particular tracts of land, be sure to discuss that. Provide how the proposed response action will meet the




objectives in a reasonable timeframe. Based on the presumed time of release and lack of TPH detections in groundwater, the objective of prevention of TPH leaching to groundwater has been met. Moreover, land usage will be restricted to commercial industrial usage, the upper groundwater-bearing unit is not a drinking water aquifer (the City of Houston supplies drinking water to the Site), and groundwater usage on Site will be prohibited. The PRP Group has completed two rounds of groundwater monitoring for TPH. In addition, all wells have been gauged for the presence of LNAPL in multiple sampling events. To demonstrate that TPH has not leached from soil to groundwater, the PRP Group will implement semiannual groundwater monitoring for three years. After three years, the PRP Group will submit a Response Action Effectiveness Report (RAER) and evaluate the stability of the soil PCLE zone. The proposed institutional controls and response action will be effective in removing the potential for human exposure to affected soil which may leach TPH to groundwater in concentrations exceeding the commercial/industrial GWGWIng PCL. Since the emergency response action removed the source of the TPH and two rounds of groundwater sampling are available, it is reasonably anticipated that groundwater concentrations will not exceed the commercial/industrial GWGWIng PCL. Response Action Objectives List the environmental media to which this applies Groundwater – CVOCsRepeat this section for each medium that has a different response action objective. State the property-specific response objectives for the PCLE zone in each media in the context of the response objectives set forth in §350.32 or §350.33 as applicable. Explain how the response action is appropriate based on the hydrogeologic characteristics, COC characteristics, and potential unprotective conditions that could continue or result during the remedial period. Groundwater PCLE Zone: The response action objectives are based on a PMZ as defined in Remedy Standard B (30 TAC §350.33) for dissolved phase CVOCs observed in Site monitoring wells. The objective is to control, prevent use of, and potential exposure to groundwater within the PMZ. The natural attenuation of CVOCS coupled with groundwater restrictions minimizes potential unprotective conditions that could result during the remedial period. CVOC concentrations in the monitoring events conducted between February 2016 and November 2017 are summarized in Appendix 2-3. Appendix 2 also contains the November 2017 laboratory report. Groundwater data from February 2016 to February 2017 were submitted in the APAR (CES, 2017a). Groundwater data for the May and August 2017 sample events were submitted in the October 6, 2017 response letter (CES, 2017b) to the June 16, 2017 TCEQ Comments on the revised APAR. As shown in the concentration-trend figures provided in Attachment 1B, COC concentrations are stable for the groundwater ingestion pathway (GWGWIng) in the six monitoring events conducted between February 2016 and November 2017. Attachment 1A-5 depicts the potentiometric surface for the November 2017 sample event. Appendix 2-6 contains the groundwater elevations for the February 2016 to November 2017 sample events. Attachment 1A-6 depicts the CVOC distribution for the 2017/2018 sample events. Groundwater flow direction at the Site is south-southeast and has been consistent over all gauging events. The groundwater PCLE zone is located on Site and there are no drinking water wells located within 0.5 miles of the Site property boundary. The proposed institutional controls and response action will be effective in removing potential human exposure to affected groundwater. The limited potential for exposure at this affected property make the use of a PMZ a viable and appropriate response action for the shallow groundwater. As described in the approved 2017 APAR, site conditions include: i) a shallow groundwater-bearing unit; ii) no groundwater use within a 0.5-mile radius of the Site property boundary; iii) drinking water supplied by the City of Houston to the Site and




surrounding residents/properties; and iv) multiple rounds of groundwater sampling which demonstrate plume stability and limited plume extent. Response Action: A PMZ with institutional controls is the proposed response action for groundwater in the PCLE zone. In accordance with 30 TAC §350.33(f)(4)(A), the use of a PMZ at the Site addresses the response action objectives. Groundwater will be sampled and analyzed for CVOCs to demonstrate that natural attenuation of constituents is operative. The results of the monitoring events will be reported on the schedule listed in Worksheet 6 (Implementation Schedule). Explain how the COCs will be handled, treated, disposed, or transferred to another media and document that the response action will not result in any additional potential exposure conditions due to response action activities. Groundwater PCLE Zone: A PMZ for the groundwater PCLE zone will not involve any potential exposure through treatment, disposal or transfer to another media. State the proposed “reasonable time frame” and provide the justification for that time frame in the context of any potential for unprotective exposures to exist or develop, COC characteristics, hydrogeologic and affected property characteristics. If the reasonable time frame is different for the different affected media or for particular tracts of land, be sure to discuss that. Provide how the proposed response action will meet the objectives in a reasonable timeframe. Groundwater PCLE Zone: The proposed time frame to prevent exposure to on-Site commercial/industrial receptors is indefinite based on implementation of institutional controls to prohibit groundwater usage. CVOC concentrations in the monitoring events conducted between February 2016 and November 2017 are summarized in Appendix 2-3. Attachment 1B-1 shows the concentration-time graphs along the groundwater PCLE zone for the four CVOCs, tetrachloroethene, trichloroethene, cis-1,2-dichloroethene, and vinyl chloride. Attachments 1B-2 and 1B-3 show the concentration-time graph for the parent CVOCs, tetrachloroethene and trichloroethene, respectively. Concentrations are decreasing along the groundwater PCLE zone from the source well at MW-01 to the downgradient well MW-06. Attachment 1B-4 shows the decreasing concentrations for the daughter product cis-1,2-dichloroethene along the groundwater PCLE zone from the source well at MW-01 to the downgradient well MW-06. Attachment 1B-5 shows the decreasing concentrations for the daughter product vinyl chloride between MW-05 and MW-06. The time frame is based on the following: a) six rounds of groundwater data from February 2016 to November 2017 which demonstrate plume stability and limited plume extent; b) restricting land usage to commercial/industrial; c) the upper groundwater-bearing unit is not a drinking water aquifer; d) the City of Houston supplies drinking water to the Site and surrounding residents/properties; and e) prohibiting groundwater usage. To date, the PRP Group has completed 10 groundwater sampling events on Site (six Site groundwater monitoring events and four quarterly groundwater monitoring events for all affected property wells). The PRP Group will implement semiannual groundwater monitoring for three years. After three years, the PRP Group will submit a RAER and evaluate the stability of the groundwater PCLE zone and degree of natural attenuation. The proposed institutional controls and response action will be effective in removing the potential for human exposure to affected groundwater. Since multiple rounds of groundwater data are available which demonstrate plume stability, additional monitoring will serve as confirmation of plume stability. Soil Response Action Objectives – Residential Manganese and Vanadium When using removal and/or decontamination with controls or controls only, demonstrate how that physical control or combination of measures will reliably contain COCs within and/or derived from the surface soil and subsurface soil PCLE zone materials over time.




As discussed under Response Action Objectives, the objectives of the Remedy Standard A removal action are to mitigate potential human exposure to manganese and vanadium concentrations exceeding the residential TotSoilComb PCL. Manganese and vanadium concentrations that may remain in the City of Houston right-of-way after the removal action will be below their residential TotSoilComb PCLs. Explain how the removal or decontamination action will reduce the concentration of COCs to the critical surface soil and subsurface soil PCL throughout the soil PCLE zone and prevent COC concentrations above the critical soil PCLs from migrating beyond the existing boundary of the soil PCLE zone. The Remedy Standard A removal action will reduce the concentration of manganese and vanadium to the residential critical PCLs (TotSoilComb exposure pathway). Soil Response Action Objectives – Commercial/Industrial TPH When using removal and/or decontamination with controls or controls only, demonstrate how that physical control or combination of measures will reliably contain COCs within and/or derived from the surface soil and subsurface soil PCLE zone materials over time. As discussed under Response Action Objectives, since the critical PCLE zone is based on exceedances of the TPH GWSoilIng PCL, the objectives of groundwater monitoring and institutional controls are to mitigate potential human exposure to TPH leaching from soil to groundwater at concentrations exceeding the critical PCLs. To date, TPH has not been detected in groundwater in this area which demonstrates that TPH leaching from soil to groundwater has not occurred. Explain how the removal or decontamination action will reduce the concentration of COCs to the critical surface soil and subsurface soil PCL throughout the soil PCLE zone and prevent COC concentrations above the critical soil PCLs from migrating beyond the existing boundary of the soil PCLE zone. TPH has not migrated to the underlying groundwater (Appendix 2-2). The i) previous removal action; ii) limited potential for unprotective human or ecological exposure at this affected property to TPH; iii) the apparent immobility of the TPH based on groundwater monitoring data and iv) the exposure pathway which requires the response action, the GWSoilIng, make the use of a groundwater monitoring and institutional controls viable and appropriate remedies to prevent TPH concentrations exceeding the critical soil PCL from migrating beyond the soil PCLE zone. Groundwater Response Action Objectives Name of groundwater-bearing unit to which this information applies

Shallow Groundwater Bearing Unit

Repeat this section for each groundwater-bearing unit for which a different response action is proposed. Groundwater classification 1 X 2 3 Is a modified groundwater response action being proposed for any part of the groundwater PCLE zone (§350.33(f)(2), (3), or (4))?

X Yes _ No

If yes, does the affected property meet the qualifying criteria for a modified groundwater response action using a waste control unit, plume management zone, or technical impracticability?

X Yes _ No

If yes, complete the appropriate portions of this report. If no to either question, complete the following: Explain how the removal or decontamination action will reduce the concentration of COCs to the critical groundwater PCL throughout the groundwater PCLE zone and prevent COC concentrations above the critical groundwater PCL from migrating beyond the existing boundary of the groundwater PCLE zone. The response action for management of the groundwater PCLE zone will be addressed through the PMZ




which allows for monitored natural attenuation of the CVOCs coupled with groundwater use restrictions. The primary lines of evidence of decontamination in the groundwater PCLE zone are:

1. A well-defined and limited extent of the on-Site CVOC plume. 2. Stable/decreasing concentrations of parent compounds tetrachloroethene and trichloroethene in the

source area well, MW-01; and 3. Stable/decreasing parent and daughter (cis-1,2-dichloroethene and vinyl chloride) concentrations in

monitoring wells MW-01, MW-5, MW-06. As shown in the concentration-time trend figures provided in Attachment 1B, COC concentrations are stable for the groundwater ingestion pathway (GWGWIng) in the six monitoring events conducted between February 2016 and November 2017. Attachment 1A-6 depicts the CVOC distribution for the 2017/2018 sample events. Sampling and analysis for the CVOCs tetrachloroethene, trichloroethene, cis-1,2-dichloroethene, and vinyl chloride in monitoring wells will provide for an immediate response if COC concentrations exhibit an increasing trend. Explain how the response action will prevent COCs from migrating to air at concentrations above the PCLs for air if the groundwater-to-air PCLs (AirGWInh-V) is exceeded. Not applicable. COC concentrations are less than the groundwater-to-air (AirGWInh-V) PCLs, therefore no response action is necessary to control this exposure pathway. Explain how the response action will prevent COCs from migrating to surface water at concentrations above the PCLs for groundwater discharges to surface water if surface water is a factor. Not applicable. As discussed in the APAR (CES, 2017a), the nearest surface water body, Kuhlman/Belmont Gully, is located approximately 760 feet northeast of the Site and is upgradient from the groundwater PCLE zone. Explain how the response action will prevent human and ecological receptor exposure to the groundwater PCLE zone. Drinking water is supplied to the Site by the City of Houston. Human receptors will be protected by institutional controls placed on the affected property to prevent usage of the shallow groundwater-bearing unit. Ecological receptors are protected since there is no exposure to groundwater within the boundary of the affected property and the nearest surface water body is approximately 760 feet northeast and upgradient of the groundwater PCLE zone.

Response Action Design Associated Information: Attachment 2A, 2B, 2C



Response Action Design Use this worksheet to provide detailed descriptions of the response action. Attach design and layout drawings and equipment specifications in Attachment 2A. Media: Soil – Manganese and VanadiumList all media to which this information applies. If the response action is different for another media, complete a separate worksheet. Provide a detailed description of the response action. Describe the removal action, decontamination, treatment system(s), and/or physical or institutional control actions that are proposed for each media and discuss the reasons for choosing the response action(s). Identify and describe any ecological services analysis and compensatory restoration plan that will be utilized (if so, include the complete ESA and compensatory restoration plan in Attachment 2C). Excavation and off-Site disposal will be used to manage COCs in the surface soil PCLE zone. The approximate limits of the excavation are depicted on Attachment 2A-1. Soil will be excavated to approximately 2.5 feet deep. No additional soil testing will be conducted since the pre-excavation soil data delineated the extent of the excavation (Appendix 2-1). Backfill will be tested for metals, SVOCs, VOCs, and TPH prior to use. After completion of the remedy, the CES Griggs Road PRP Group will submit a Response Action Completion Report (RACR). Describe all major treatment system components and equipment of the response action. Illustrate the response action design and provide equipment specifications in Attachment 2A. Not applicable List permits or registrations needed to construct or implement the response action, including permits or registrations needed to conduct studies or tests. For VCP sites, list the permits that would be required if the site was not in the VCP (required by the VCP).

Permitting/Registration Authority* Type of permit/registration

Permit or registration number if already

issued

Anticipated application date

City of Houston Grading Permits for Excavation and fill Not applicable Not applicable per 30 TAC 333.8(b) City of Houston Street Cut Permit

‘* The construction area is less than 1-acre and a Notification of Intent (NOI) for TXR150000 (Construction Sites that Discharge Stormwater Associated with Construction Activity) is not required. Identify and discuss the results of any studies or tests, such as pilot studies, feasibility studies, technical impracticability studies, treatability studies, and/or toxicity studies conducted or proposed to be conducted at the affected property. Discuss the reason for the study or test and how it verifies the effectiveness and appropriateness of the chosen response action or documents that a particular response action is not appropriate for the affected property. Describe how the results of completed studies or tests determined the design or choice of response action. Attach any separate reports and supporting documentation in Appendix 3. Pre-excavation confirmation soil samples were collected on January 18 and 19, 2018 to determine the extent of the excavation. Appendix 2-1 and Attachment 2A summarizes the pre-excavation confirmation sample results. Appendix 2 contains the January 2018 laboratory reports.




Response Action Design Use this worksheet to provide detailed descriptions of the response action. Attach design and layout drawings and equipment specifications in Attachment 2A. Media: Soil – Total Petroleum HydrocarbonsList all media to which this information applies. If the response action is different for another media, complete a separate worksheet. Provide a detailed description of the response action. Describe the removal action, decontamination, treatment system(s), and/or physical or institutional control actions that are proposed for each media and discuss the reasons for choosing the response action(s). Identify and describe any ecological services analysis and compensatory restoration plan that will be utilized (if so, include the complete ESA and compensatory restoration plan in Attachment 2C). The soil COC, TPH, will be monitored by the collection of groundwater samples from a monitoring well installed downgradient of the soil PCLE zone. Groundwater monitoring and institutional controls will be used to monitor groundwater conditions in the TPH soil PCLE zone adjacent to the south tank farm. Groundwater samples will be collected from MW-08 and analyzed for TPH by the Texas 1005 analytical method. If groundwater concentrations increase above 1.5 mg/L (one-half of the critical PCL of 2.9 mg/L), the PRP Group will evaluate the need for additional response actions. TPH in groundwater has been non-detectable to date. After completion of three years of monitoring, the PRP Group will submit a RACR summarizing the groundwater monitoring results. Describe all major treatment system components and equipment of the response action. Illustrate the response action design and provide equipment specifications in Attachment 2A. Not applicable. List permits or registrations needed to construct or implement the response action, including permits or registrations needed to conduct studies or tests. For VCP sites, list the permits that would be required if the site was not in the VCP (required by the VCP).



issued


Not applicable Identify and discuss the results of any studies or tests, such as pilot studies, feasibility studies, technical impracticability studies, treatability studies, and/or toxicity studies conducted or proposed to be conducted at the affected property. Discuss the reason for the study or test and how it verifies the effectiveness and appropriateness of the chosen response action or documents that a particular response action is not appropriate for the affected property. Describe how the results of completed studies or tests determined the design or choice of response action. Attach any separate reports and supporting documentation in Appendix 3. Not applicable.




Response Action Design Use this worksheet to provide detailed descriptions of the response action. Attach design and layout drawings and equipment specifications in Attachment 2A. Media: Groundwater List all media to which this information applies. If the response action is different for another media, complete a separate worksheet. Provide a detailed description of the response action. Describe the removal action, decontamination, treatment system(s), and/or physical or institutional control actions that are proposed for each media and discuss the reasons for choosing the response action(s). Identify and describe any ecological services analysis and compensatory restoration plan that will be utilized (if so, include the complete ESA and compensatory restoration plan in Attachment 2C). A PMZ with natural attenuation monitoring and institutional controls will be used to manage CVOCs in the groundwater PCLE zone. As discussed in the Response Action Objectives, evaluation of the groundwater monitoring data indicates that CVOC concentrations are stable or decreasing and the areal extent of the plume is limited and well-defined. The groundwater PCLE zone will be monitored semiannually for three years by collecting groundwater samples at MW-01, MW-05, MW-06 and proposed point of exposure well (POE), MW-09 (see RAP Worksheet 2.1) for the analyses of CVOCs. After three years, the CES Griggs Road PRP group will evaluate the stability of the groundwater PCLE zone. The PRP Group will submit a RAER documenting the results of the three-year evaluation and providing recommendations for additional monitoring or No Further Action (NFA). Upon approval of the NFA, the PRP Group will plug and abandon Site monitoring wells and submit a RACR for TCEQ approval. Describe all major treatment system components and equipment of the response action. Illustrate the response action design and provide equipment specifications in Attachment 2A. The response action design is the PMZ depicted in Attachment 2D. Three attenuation monitoring points (AMPs) are proposed for the PMZ: MW-01 and MW-05 for the CVOCs tetrachloroethene, trichloroethene, and cis-1,2-dichloroethene and MW-01, MW-05, and MW-06 for vinyl chloride. The AMP wells are located in the PCLE zone. MW-06 is designated as the POE well for the CVOCs tetrachloroethene, trichloroethene, and cis-1,2-dichloroethene and the proposed monitoring well MW-09 is designated as the POE well for vinyl chloride. The monitoring well will be installed and developed as described in Section 3.2 (Assessment Methods) of the APAR (CES, 2017a). List permits or registrations needed to construct or implement the response action, including permits or registrations needed to conduct studies or tests. For VCP sites, list the permits that would be required if the site was not in the VCP (required by the VCP).



issued


Not applicable Identify and discuss the results of any studies or tests, such as pilot studies, feasibility studies, technical impracticability studies, treatability studies, and/or toxicity studies conducted or proposed to be conducted at the affected property. Discuss the reason for the study or test and how it verifies the effectiveness and appropriateness of the chosen response action or documents that a particular response action is not appropriate for the affected property. Describe how the results of completed studies or tests determined the design or choice of response action. Attach any separate reports and supporting documentation in Appendix 3. Not applicable.

Plume Management Zone Associated Information: Attachments 2D, 2E



Complete this worksheet when a PMZ is proposed as part of the response action. Include in Attachment 2D a map of the proposed PMZ with alternate POE(s) and attenuation monitoring points identified and the current groundwater PCLE zone. If a PMZ is not proposed, do not submit this worksheet. Groundwater-bearing unit Shallow Groundwater Bearing UnitRepeat this worksheet for each groundwater-bearing unit for which a PMZ is proposed. Groundwater classification X 2 3 Provide justification as to why the PMZ is appropriate in accordance with §350.33(f)(4)(A). Include supporting documentation in Attachment 2E. Appendix 2-3 summarizes the groundwater CVOC concentrations and Attachment 1A-6 shows the 2017-2018 CVOC concentrations. Attachment 2E provides supporting documentation for the PMZ. Site monitoring wells will be gauged for water levels during the implementation of the PMZ. CVOC concentrations will be monitored for an increasing trend by collecting groundwater samples at MW-01, MW-05, MW-06, and proposed POE well MW-09 during the implementation of the PMZ. The following factors support the management of the groundwater PCLE zone with a PMZ response action:

1. The sampling events conducted between February 2016 and November 2017 provide sufficient data to demonstrate plume stability. The plume is well-defined and limited in areal extent.

2. The primary lines of evidence show decontamination in the groundwater PCLE zone. 3. The secondary lines of evidence show decontamination in the groundwater PCLE zone. 4. The affected property has COC concentrations near PCLs. 5. The affected property has a single layer unconsolidated groundwater-bearing unit with

hydrogeologic conditions that do not appear to change over time (i.e., consistent groundwater gradient as shown in Attachment 1A-5).

In accordance with 30 TAC 350.33(f)(4)(A), the use of a PMZ with monitored natural attenuation and institutional controls is an appropriate response action for the CVOC critical PCLE Zone. The proposed PMZ is presented in Attachment 2D. Attachment 2E contains the supporting documentation. Is the alternate POE proposed to be beyond the current limits of the PCLE zone? X Yes NoIf yes, how far? 75 feet (see proposed well location on

Attachment 2D) (§350.37(l) or (m) as applicable)

Is it to be off-site? Yes X NoOn an off-site property that currently does not contain a residential-based groundwater PCLE zone?

Yes X No If yes and this is a Class 2 groundwater, provide the basis for concluding that this groundwater does not have a reasonably anticipated future beneficial use (§350.37(l)(3)). Not applicable. Is NAPL present? Yes X NoIf so, describe how the response action will achieve the performance criteria in §350.33(f)(4)(E). Not applicable. If this is a Class 2 groundwater, explain how the response action will ensure that leachate from the surface soil and subsurface soil PCLE zones will not increase concentration of COCs greater than the current measured concentrations (at time of RAP submittal). (§350.33(a)(2)) A surface or subsurface soil PCLE zone was not identified for the CVOCs. All soil concentrations were below the GWSoilIng residential assessment level. Therefore, leachate will not increase COC concentrations above those measured at the time of this RAP submittal.




Provide the basis that the COCs will not migrate beyond the downgradient boundary of the PMZ at concentrations above the critical PCL. Include supporting documentation in Attachment 2E. The primary source area for the CVOC PCLE zone was identified in the APAR as the drum cleaning sump (Notice of Registration Unit 001) located on the western side of 4904 Griggs Road near MW-01. The waste code for this unit was 9014206H (Halogenated hydrocarbons). As shown in Attachment 1A-5, the groundwater gradient is to the southeast from the source area. Appendix 2-6 contains the groundwater elevations for the February 2016 to November 2017 gauging events. The six groundwater monitoring events conducted between February 2016 and November 2017 have shown a stable/decreasing plume. The following factors support the management of the groundwater PCLE zone with a PMZ response action:

1. The sampling events conducted between February 2016 and November 2017 provide sufficient data to demonstrate plume stability.

2. The primary lines of evidence show decontamination in the groundwater PCLE zone. 3. The secondary lines of evidence show decontamination in the groundwater PCLE zone. 4. The plume is well-defined and limited in areal extent.

Describe the methods used to determine that there are no artificial penetrations which can allow COCs to migrate from the groundwater PCLE zone to currently unaffected groundwater-bearing units. Include supporting documentation in Attachment 2E. The APAR summarized the receptor survey which was conducted within the vicinity of the affected property to identify artificial penetrations which could allow COCs to migrate from the uppermost groundwater-bearing unit to deeper unaffected groundwater-bearing units. Institutional controls will effectively eliminate the potential for future artificial penetrations which could allow COCs to migrate to unaffected groundwater-bearing units.




List the attenuation action level determined for each attenuation monitoring point. Illustrate the proposed attenuation monitoring points and the groundwater PCLE zone on the map in Attachment 2D. Include all calculations and other methods of determining the attenuation action levels in Attachment 2E.

COC Attenuation Monitoring Point (well number) Attenuation Action

Level (mg/L)

Attenuation Action Level limited by

AirGWInh-V or existing COC concentration?

Y/NTetrachloroethene MW-01 0.0074* Yes MW-05 0.0056 No

Trichloroethene MW-01 0.022* Yes MW-05 0.0088 No

cis-1,2-Dichloroethene MW-01 0.15* Yes MW-05 0.092 No

Vinyl chloride MW-01 0.0087* Yes MW-05 0.0041 No

MW-06 0.0056* Yes

* - Maximum concentrations adjusted by 10% to account for normal sampling and analytical variations.


Attachment 2E Page 20 of 29 ID No.: VCP 2751 Report Date: March 7, 2018


CES Griggs Road VCP Site Houston, Harris County, Texas

2E.1 PMZ Justification Appendix 2-3 summarizes the CVOC data from February 2016 to November 2017. Tetrachloroethene concentrations have been below the critical PCL of 0.005 milligram/liter (mg/L) since the February 2017 sample event. Tetrachloroethene concentrations have not exceeded the PCL in other Site monitoring wells. Trichloroethene concentrations in the source area well MW-01 ranged from 0.013 to 0.020 mg/L, slightly above the critical PCL of 0.005 mg/L. Trichloroethene concentrations slightly exceeded the critical PCL in downgradient well MW-06 in the February and March 2017 sample events but have been below in the May to November 2017 sample events. The concentrations of the daughter product cis-1,2-dichloroethene exceeded the critical PCL of 0.070 mg/L in the source area well MW-01 and downgradient well MW-05. The maximum concentration of 0.14 mg/L in MW-01 (in the presumed source area) is just twice the critical PCL. cis-1,2-Dichloroethene concentrations in downgradient well MW-05 are at or below the critical PCL. The maximum concentration of the daughter product trans-1,2-dichloroethene is 0.0034 mg/L, approximately two orders of magnitude lower than the critical PCL of 0.10 mg/L. The vinyl chloride concentrations in the source area well MW-01 ranged from 0.0044 to 0.0079 mg/L, however concentrations in downgradient well MW-06 ranged from 0.0037 to 0.0051 mg/L, just slightly above the critical PCL of 0.002 mg/l. The following factors support the management of the groundwater PCLE zone with a PMZ response action:

1. The sampling events conducted between February 2016 and November 2017 provide sufficient data to demonstrate plume stability. The CVOC plume is well-defined and limited in areal extent.

2. The primary lines of evidence for decontamination in the groundwater PCLE zone are: a. Stable/decreasing concentrations of parent compounds tetrachloroethene and trichloroethene

from the source zone well, MW-01; b. The presence of the daughter products cis-1,2-dichloroethene and vinyl chloride; and c. Stable/decreasing parent (tetrachloroethene and trichloroethene) and daughter (cis-1,2-

dichloroethene and vinyl chloride) concentrations over time. 3. The secondary lines of evidence for decontamination in the groundwater PCLE zone are:

a. Methane enrichment in wells within and adjacent to the groundwater PCLE zone: MW-01, MW-06, MW-06 and MW-07 (Appendix 2-4) indicating that natural attenuation is operative; and

b. Anaerobic conditions at the site as shown by low dissolved oxygen (Appendix 2-5). 4. The affected property has COC concentrations near PCLs. 5. The affected property has a single layer unconsolidated groundwater-bearing unit with hydrogeologic

conditions that are consistent (i.e., consistent groundwater gradient as shown in Attachment 1A-5). In accordance with 30 TAC 350.33(f)(4)(A), the use of a PMZ with monitored natural attenuation and institutional controls is an appropriate response action for the CVOC Critical PCLE Zone. The proposed PMZ is presented in Attachment 2D. 2E.2 PMZ Map and Location of Attenuation Monitoring Points (AMP) The proposed PMZ will be monitored using the monitoring well network shown on Attachment 3A. The POE wells, MW-06 and MW-09, are located at the PMZ boundaries for tetrachloroethene, trichloroethene, and cis-1,2-dichloroethene (MW-06) and vinyl chloride (MW-09), respectively. Two AMPs are proposed for CVOCs tetrachloroethene, trichloroethene, and cis-1,2-dichloroethene: MW-01 and MW-05. Three AMPs are proposed for vinyl chloride: MW-01, MW-05, and MW-06. The AMP wells are located in the PCLE zone. 2E.3 PMZ Map and Location of Point of Exposure (POE) Points The location and areal extent of the proposed PMZ are based on the presumed CVOC source area (former sump), the historical groundwater data (Attachment 1A-6; Appendix 2-3), and inferred limits of the PCLE zone from the potentiometric surface (Attachment 1A-5). The two POE wells are approximately 200 feet (MW-01 to


Attachment 2E Page 21 of 29 ID No.: VCP 2751 Report Date: March 7, 2018


MW-06) and 300 feet (MW-01 to MW-09 [proposed location]) from the source area well, MW-01. To verify and determine the ideal positions for the POE wells for targeted CVOCs, three temporary wells were installed on the Site and three temporary wells on Grace Lane east of the Site. These wells confirmed the down-gradient extent of CVOCs (and vinyl chloride in particular) detected in shallow Site groundwater. The three temporary wells on Site were installed in positions proximate to the down gradient extent of CVOCs directly down gradient of the source area (based on verified Site groundwater flow direction). The six temporary wells were properly plugged following ground water sample collection. Groundwater samples were collected from each temporary well and analyzed for CVOCs. Attachment 1A-6 and Appendix 2-3 summarizes the data for these six wells. Attachment 1A-5 shows the groundwater gradient the November 2017 sample event. The Site groundwater gradient is predominantly to the southeast which is consistent with previously measured gradients. As shown on Attachment 1A-6, the concentrations for the CVOCs tetrachloroethene, trichloroethene, and cis-1,2-dichloroethene are below the critical PCLs in monitoring well MW-06. MW-06 is designated as the POE for tetrachloroethene, trichloroethene, and cis-1,2-dichloroethene. Vinyl chloride concentrations in MW-06 slightly exceeded (~ 2 ppb) the critical PCL. Trichloroethene, cis-1,2-dichloroethene, and vinyl chloride concentrations were below the critical PCLs in TMW-3 and TMW-4. Based on the southeasterly gradient shown in Attachment 1A-5, these wells are situated directly down gradient of the presumed source area. As such, a location between TMW-3 and TMW-4 allows down gradient delineation of vinyl chloride. Upon the concurrence of the TCEQ, the permanent monitoring well MW-09 will be installed and sampled at the proposed POE location shown in Attachment 2D. This location, MW-09, is designated as the POE for vinyl chloride. 2E.4 Attenuation Action Levels (AAL) Groundwater samples will be analyzed for the CVOCs tetrachloroethene, trichloroethene, cis-1,2-dichloroethene, and vinyl chloride. The AALs are shown on RAP Worksheet 2.1 and the AAL calculations are provided in Appendix 2E. The monitoring and sampling points are provided in RAP Worksheet 3.1 and Attachment 3A. 2E.5 Statistical Evaluation of Groundwater Monitoring Data This section describes the quantitative evaluation of data trends for the PMZ that will be discussed in the RAER. Both graphical and statistical methods may be utilized to present the primary line of evidence of plume stability. Concentrations for individual wells will be provided in the RAER. Concentration versus time plots for individual monitoring wells with detectable CVOC concentrations will be provided in the RAER. Attachments 1B-1 to 1B-5 contain the concentration versus time plots for CVOCs, tetrachloroethene, trichloroethene, cis-1,2-dichloroethene, and vinyl chloride. In addition, statistical evaluations, such as Mann-Kendall or Theil-Sen Tests can be used, if needed, to evaluate plume stability. These trend tests are performed on time series data and can handle missing values. The underlying data do not need to follow a specific distribution. A minimum of four discrete sample events are required to perform the statistical evaluations. These tests can be performed using the ProUCL software provided by the U. S. Environmental Protection Agency (USEPA, 2016).

Institutional Control Associated Information: Appendices 4, 5



Complete this worksheet if an institutional control will be used as part of the response action. Include a draft of the proposed institutional controls in Appendix 4. Provide a list of landowners from whom landowner concurrence will be requested, as necessary, in Appendix 5. Specify the property for which this applies. 4904 Griggs RoadRepeat this worksheet for each different property for which an institutional control will be used.

Institutional Control

Type of Institutional Control1 Property Ownership

Anticipated Filing Date2Deed

Notice Restrictive Covenant

VCP Certificate of Completion

Equivalent zoning or

governmental ordinance

Check if pertinent tract is owned by the person

Check if the pertinent tract is owned by an innocent owner

or operator Document use of commercial/industrial land use (§350.31(g)) X X

120 days after approval of the RAP

Document use of physical or institutional control under Remedy Standard B §350.31(g)) X X


Document notice of on-going long-term response action (§350.31(h))

Document use of occupational inhalation criteria as RBELs (§350.74(b)(1))

Document variance from the default exposure factors (§350.74(j)(2)(L))

Document the use of a non-default soil exposure area (§350.51(l)(3)&(4))

Document WCU exclusion area (§350.33(f)(2))

Document establishing a PMZ (§350.33(f)(4)(C)(I)) X X

120 days after installation of POE well

Document the demonstration of technical impracticability (§350.33(f)(3)(F))

Relocation of soils containing COCs for reuse (§350.36(b)(4) and (c)(4))

1 Check the appropriate box(es) to indicate the type of institutional control required for the proposed response action. 2 Specify date or amount of time after RAP approval.

Institutional Control Associated Information: Appendices 4, 5



Complete this worksheet if an institutional control will be used as part of the response action. Include a draft of the proposed institutional controls in Appendix 4. Provide a list of landowners from whom landowner concurrence will be requested, as necessary, in Appendix 5. Specify the property for which this applies. 5910 Wayland StreetRepeat this worksheet for each different property for which an institutional control will be used.

Institutional Control

Type of Institutional Control1 Property Ownership

Anticipated Filing Date2Deed

Notice Restrictive Covenant

VCP Certificate of Completion

Equivalent zoning or

governmental ordinance

Check if pertinent tract is owned by the person

Check if the pertinent tract is owned by an innocent owner

or operator Document use of commercial/industrial land use (§350.31(g)) X X


Document use of physical or institutional control under Remedy Standard B §350.31(g)) X X


Document notice of on-going long term response action (§350.31(h))

Document use of occupational inhalation criteria as RBELs (§350.74(b)(1))

Document variance from the default exposure factors (§350.74(j)(2)(L))

Document the use of a non-default soil exposure area (§350.51(l)(3)&(4))

Document WCU exclusion area (§350.33(f)(2))

Document establishing a PMZ (§350.33(f)(4)(C)(I))

Document the demonstration of technical impracticability (§350.33(f)(3)(F))

Relocation of soils containing COCs for reuse (§350.36(b)(4) and (c)(4))

1 Check the appropriate box(es) to indicate the type of institutional control required for the proposed response action. 2 Specify date or amount of time after RAP approval.

Performance Measures and Potential Problems



Performance Measures List and describe the performance measures for each environmental medium containing a PCLE zone that will be used to determine if reasonable progress is being made by the response action in a timely manner. Use these measures to document effectiveness of the response action in the RAER. Residential Soil PCLE Zone for Manganese and Vanadium: No performance measures are needed for this soil PCLE zone. The submittal of the RACR will document the effectiveness of the response action. Commercial/Industrial Soil PCLE Zone - TPH: The performance measure for this soil PCLE zone is monitoring groundwater for TPH. If groundwater concentrations in MW-08 increase above 1.5 mg/L (one-half of the critical PCL of 2.9 mg/L), the PRP Group will evaluate the need for additional response actions. The effectiveness of the response action will be documented in the RAER which will be submitted three years after initiation of the response action. Groundwater PCLE Zone - CVOCs: CVOC concentrations will be monitored semiannually in groundwater for three years to evaluate the effectiveness of the remedy in controlling the groundwater in the critical PCLE zone. A continued stable or decreasing trend in CVOC concentrations will indicate that natural attenuation is occurring and is an effective response action. Potential Problems Complete the table for the response action. When the response action consists of several components or multiple actions, complete one table for each major component or action. Response Action Name/Designation: Commercial/Industrial Soil PCLE Zone - TPH List the potential problems that might be reasonably anticipated for the response action, describe the impact of each problem, and the response to the problem.

Description of the Potential Problem Impact

Will this cause a response

action failure? Corrective Response

Yes NoIncrease in COC concentrations

May indicate leaching of soils to the groundwater

If COC concentrations increase to one-half the GWGWIng PCL (1.5 mg/L), the MW-08 will be resampled. If the increasing trend is confirmed, then the response action will be re-evaluated.

Response Action Name/Designation: Groundwater PCLE Zone - CVOCs List the potential problems that might be reasonably anticipated for the response action, describe the impact of each problem, and the response to the problem.

Description of the Potential Problem Impact

Will this cause a response

action failure? Corrective Response

Yes NoIncrease in COC concentrations or expansion of the PCLE Zone

May indicate a contribution from an off-site, upgradient source or natural attenuation conditions are not favorable for COC degradation

If COC concentrations exhibit an increasing trend in the AMP wells, the monitoring wells will be resampled. If the increasing trend is confirmed, then the response action will be re-evaluated.

Monitoring and Sampling Associated Information: Attachment 3A



List the monitoring and sampling of COC concentrations or other parameters that will be conducted during the response action. Illustrate the monitoring or sampling locations in Attachment 3A. If statistics or geostatistics will be used, provide details in Appendix 7. If monitoring or observation wells will be constructed for the response action, provide well construction details in Attachment 2B if not previously provided.

Monitored Media COC Other

parameter (specify)

Sampling Method

Sampling points or locations

Depth/Height (ft.) Screen

Interval (bgs)

Analytical or Field Screening

Method

Sampling or Monitoring Frequency

Surface Soil (Attachment 2A)

Not applicable – Pre-excavation confirmation sampling conducted January 18 to January 19, 2018. See Appendix 2-1 and Attachment 2A.

Subsurface Soil Not applicable

Groundwater (Attachment 3A)

TPH Water Level Low flow Interface Probe MW-08 15 – 25 feet

Water level indicator, interface probe, Texas 1005

Semiannually for three years

CVOCs Water Level Low flow Interface Probe

MW-01 15 – 30 feet Water level indicator, interface probe, SW-846 8260 (CVOCs only)


MW-05 18 – 28 feetMW-06 16 – 26 feetMW-09 (new) Approximately

16 to 27 feet

Surface water Not applicable

Sediment Not applicable

Air Not applicable Other Media (specify) Not applicable Explain the reasons for the above-listed monitoring and sampling plan. Commercial/Industrial Soil PCLE Zone - TPH: The soil COC, TPH, will be monitored by the collection of groundwater samples from a monitoring well installed downgradient of the soil PCLE zone. The groundwater COC concentrations for TPH will be monitored semiannually for three years to evaluate soil leaching and PCLE zone stability. Groundwater PCLE Zone – CVOCs: The groundwater COC concentrations for CVOCs will be monitored semiannually for three years to evaluate plume stability and natural attenuation. These data along with the February 2016 to November 2017 quarterly monitoring data will be used to demonstrate natural attenuation of CVOCs and plume stability.

Operation and Maintenance RAP Worksheet 3.2 Page 26 of 29 ID No.: VCP 2751 Report Date: March 7, 2018


Use this worksheet to describe the operation and maintenance (O&M) activities for each response action. In situations where the response action consists of more than one major component, for clarity one worksheet can be completed for each major component. Response Action Name/Designation: Commercial/Industrial Soil PCLE Zone -TPH and

Groundwater PCLE Zone – CVOCsList all portions of the response action to which this information applies. Describe the O&M and inspection activities that will be required to operate and maintain response action components. Monitoring wells will be inspected for damage during sampling events and necessary repairs will be made. If annual well depth measurements indicate that silt is accumulating in the screened zone and is affecting sample acquisition or quality, then the well will be re-developed. List and discuss the key operating parameters for a properly functioning response action. Address how changes in these parameters will result in operating changes, providing sufficient detail to explain how the operator will know the component is functioning properly. See O&M and inspection activities above. List the routine tasks required to operate the response action. See O&M and inspection activities above. List the routine tasks required to maintain the response action, including scheduled inspections, maintenance, and component replacement. See O&M and inspection activities above.

Confirmation Sampling Plan Associated Information: Attachment 4A



List the COCs and other parameters that will be sampled to confirm completion of the response action. Illustrate the monitoring or sampling locations in Attachment 4A. If monitoring or observation wells will be constructed for the response action, provide well construction details in Attachment 2B if not previously provided. If needed, describe the sample collection and handling methods, if not previously provided, in Appendix 6. Explain the reasons for the above-listed sampling plan. Discuss statistical or geostatistical methodology(ies) which will be applied, if any, in the data collection process. Discuss any assumptions made in the statistical/geostatistical assessment, and how they will be met.

Monitored Media COC Other

parameter (specify)

Sampling Method

Sampling points or locations

Depth/Height (ft.) Screen

Interval (bgs)

Analytical or Field Screening

Method

Sampling or Monitoring Frequency

Surface Soil Pre-excavation confirmation sampling conducted January 18 to January 19, 2018. See Appendix 2-1 and Attachment 2A. Subsurface Soil Not applicable

Groundwater (Attachment 3A)

TPH Water Level Low flow Interface Probe MW-08 15 – 25 feet

Water level indicator, interface probe, Texas 1005


CVOCs Water Level Low flow Interface Probe

MW-01 15 – 30 feet Water level indicator, interface probe, SW-846 8260 (CVOCs only)


MW-05 18 – 28 feetMW-06 16 – 26 feetMW-09 (new) Approximately

16 to 27 feet

Surface water Not applicable

Sediment Not applicable

Air Not applicable Other Media (specify) Not applicable Commercial/Industrial Soil PCLE Zone – TPH and Groundwater PCLE Zone – CVOCs The confirmation sampling locations are the same as the monitoring and sampling points (see RAP Worksheet 3.1). RAERs will be submitted to the TCEQ as listed in Worksheet 6.0 to demonstrate effectiveness of the response action. After three years of semiannual monitoring, a RAER will be submitted which summarizes the data and provides recommendations for additional groundwater monitoring or a NFA request. After approval of the NFA request, monitoring wells will be plugged and abandoned and proof of the abandonment will be submitted to TCEQ in the RACR.

Post-Response Action Care Associated Information: Attachments 5A-5C

RAP Worksheet 5.0 Page 28 of 29 ID No.: VCP 2751 Report date: March 7, 2018


Complete this worksheet only if Remedy Standard B will be used. What is the proposed initial post-response action care period? (default 30 yr.) 3 years If the proposed initial post-response action care period is less than 30 years, provide a technical justification in accordance with §350.33(h). Since Site investigation began, an abundance of groundwater data has been collected which has allowed a good understanding of Site conditions. Quarterly groundwater monitoring was conducted from February 2016 to November 2017 and six monitoring events were completed prior to 2018. The data indicate that COC concentrations in groundwater are stable. Three years of semiannual monitoring (total of five years of monitoring including the 2016 and 2017 data) is proposed in this RAP to confirm natural attenuation and plume stability. After three years of semiannual monitoring, a RAER will be submitted which summarizes the data and provides recommendations for additional groundwater monitoring or a NFA request. After approval of the NFA request, monitoring wells will be plugged and abandoned and proof of the abandonment will be submitted to TCEQ in the RACR. Upon approval of the RACR, no post-response action care is needed. What is the foreseeable land use during the post-response action care period? Commercial/industrial Describe how the future use of the property will not compromise the integrity of the physical controls, will not interfere with the function of the monitoring systems, will not pose a threat to human health or the environment, and will be in accordance with any institutional controls. Future use of the property will be commercial/industrial and usage of the upper groundwater-bearing zone will be prohibited. Prospective purchasers of the property will be notified of the groundwater monitoring requirements and institutional controls. The PRP Group will continue to work closely with the Bankruptcy Trustee to ensure that the monitoring systems are not compromised and land use will be in accordance with the institutional controls. Briefly describe the proposed post-response action care activities. Describe the type of monitoring and/or inspections to be performed. Discuss the rationale for not including COC(s) analyzed during the response action, monitoring or sampling point location, frequency of monitoring and/or inspections, and the duration of the monitoring program. Not applicable. Will PRAC sampling procedures be the same as those as previously documented for monitoring and/ or confirmation sampling? Not Applicable

Yes

No

If no, provide in Appendix 6 a description of the monitoring or sampling collection procedures to be conducted during the post-response action care period. Cost Estimate Complete this portion of the form only if a physical control is proposed (installed hydraulic control system, slurry wall, cap, etc.). Provide in Attachment 5B a detailed cost estimate for a third party to operate and maintain the physical control during the PRAC period, based on current dollar amount. Specify the physical control to which this information applies Not ApplicableComplete this worksheet for each physical control that will be used as part of the response action. What is the total estimated annual cost of O&M for the PRAC period? $ What is the total estimated cost for a third party to perform PRAC activities? $ Identify the type of financial assurance mechanism to be used, and the contact person managing fiduciary responsibility, if known. Not Applicable Does the person

voluntary cleanup program response action plan · august 20, 2016 the prp group submitted a...

Documents