SEPA United States Environmental Protection Agency U.S. Environmental Protection Agency (EPA) W.R.G race (Acton Plant) Superfund Site Community Update EPA Superfund Community Involvement July 2009 This community update provides you with information on the activities ongoing at the W.R, Grace Superfund site in Concord & Acton MA. Northeast Area Remedial Action Activities The Northeast Area Groundwater Concept Design has been reviewed and conditionally approved by the United States Environmen- tal Protection Agency (USEPA) and the Mas- sachusetts Department of Environmental Protection (MassDEP) with input from key stakeholders from the Town of Acton, the Acton Water District and the Acton Citi- zens for Environmental Safety.The Concept Design, which is the engineering plans for the treatment system, includes installation of up to 3 groundwater extraction wells and 2 reinjection wells as well as a groundwater treatment system.This work will occur on Linde Inc. property (formerly known as BOC Gases) as shown on Figure I .The ba- sic layout of the extraction, reinjection and treatment system components is shown on Figure 2 and will be housed in an enclosed structure. The Northeast Area treatment system will extract and treat contaminated groundwa- ter focusing on the area of highestVinylidene Chloride (VDC) concentrations as required by the 2005 EPA Record of Decision (ROD). The ROD documented the final site areas that need to be cleaned up and the ap- propriate clean up leveis.Treatment of the extracted groundwater will include air strip- ping for volatile organic compound (VOC) removal and a filter for arsenic removal.The treated water will be re-injected back into the groundwater in the Northeast Area, Overall Site Status In 1984,W. R. Grace installed a groundwater extraction, treatment and discharge system know as the Aquifer Restoration System (ARS). From 1985 until 2008, the ARS has removed approximately 5,936 pounds of totalVOC's and pumped over 4,787 million of gallons of groundwater. Between 1994 and 1997, approximately 177,000 cubic yards of contaminated soil and sludge from the former lagoons were treated and placed on the existing Industrial "Uv, Northwest view ofWR Grace (Acton Plant) site from atop the Industrial Landfill Landfill and the landfill was capped. Between 1997 and 2005, investigations were com- pleted to define the extent of any remaining groundwater, sediment and surface water contamination at the Site. From early 2007 to the present,W. R. Grace and their consultants gathered additional site data and prepared various reports for the engineering design(s) of the final cleanup activities at the site.The additional site work also included installing, sampling and testing of additional extraction wells and various monitoring wells both north and south of the MBTA rail line.W.R.Grace also obtained additional sediment samples, and character- ized ecological habitats and wetland char- acteristics from both Sinking Pond and the North Lagoon Wetland. W.R.Grace intends to begin installation of a test extraction and injection well in the Northeast Area of this site in June of 2009,These test wells will be used to complete the final design of the Northeast Area groundwater extraction, treatment and reinjection system for this area. Landfill Area Groundwater Treat- ment System In addition to the Northeast Area ground- water design plan,W. R. Grace is also pre- paring a separate design plan for the new groundwater extraction treatment and sur- face water discharge system for the landfill area on the Grace property. It is expected that the Landfill Area Groundwater Concept Design will be submitted to EPA, MassDEP and the stakeholders in September 2009. This second groundwater treatment system will remove metals and VOC's from the contaminated groundwater at the former Industrial Landfill Area.This new treatment system will be located on the W.R. Grace property, south of the MBTA rail line. Acton Water District (AWD) The Acton Water District continues to op- erate and maintain air strippers to remove any volatile organic compounds which may be present in groundwater pumped from the Assabet I .Assabet 2'2A,and the School continued on page 2 > SDMS DocID 457595 ------- ristofferson 0 / Scribner, Area of 2009 ^ Remediatiog^ Activities^ / , LINDE PROPERTY (FORMERLY BOC @ASES>' ^ -"t. = • J" pnrcTr^ / Hi ' H Explanation ACTON WATER DISTRICT PUBLIC SUPPLY WELL APPROXIMATE PROPERTY BOUNDARY Figure 1 - Location of Northeast Area Remediation Activities, 2009 / 2010 W.R. Grace (Acton Plant) Superfund Site ------- APPROXIMATE AREA TO BE CLEARED (0.24 ACRES) UTILITY TRENCH FOR TREATMENT SYSTCM TREATMENT BUILDING-i © MW-5S EXPLANATION UNDE PROPERTY BOUNDARY (APPROXIMATE) MW-06 © MONITORING mi (SINGLE OR CLUSTER) NE-t PROPOSED EXTRACTION WEI1 RE-1 PROPOSED REINJECT10N WELL d I UTIUTY POLE EXISTING OVERHEAD UTILITIES EXISTING UNDERGROUND UTILITIES APPROX. 3 FT. FROM PAVEMENT (WATER 4 ELECTRIC) © MW-49 EXISTING FENCE J Figure 2 - Northeast Area with Treatment System Location ------- ALL LOCATIONS ARE APPROXIMATE Christoffenson 0 -N- Lawsbrook Scrlbner ) M LINDE PROPERTY / --vr , ,®XA Rail Line £ I W.R. GRACE PROPERTY BOUNDARY \ INDUSTRIAL LANDFILL \f WRG-3 (Proposed) Assabet 1 1,000 Scale m feet Approximate EXPLANATION — W.R. GRACE PROPERTY BOUNDARY # PUBUC WATER SUPPLY WELL FORMER WASTEWATER LAGOON APPROXIMATE DIRECTION OF GROUNDWATER FLOW PRIOR TO OPERATION OF ARS VDC CONCENTRATION 2008 ~j 201 - 560 ugA VDC | 101-200 ug/L VDC 61-100 ugA VDC n 31-60 ug/L VDC 7-30 ugA VDC SAMPLES COLLECTED BETWEEN AUG 13 AND NOV, 5, 2008 VDC CONCENTRATIONS SHOWN ARE MAXIMUM REGARDLESS OF DEPTH. CONCENTRATION BOUNDARIES ARE APPROXIMATE. VDC = MNYUDENE CHLORIDE = 1.1-lXCHLOROETHENE Figure 3 - Distribution of VDC in Groundwater, 2008 ------- Street we!l field (Christofferson.Lawsbrook, and Scribrter wells). Low concentrations of several VOCs have been detected in un- treated raw water samples from these wells prior to treatment. The treatment system for the School Street and AssabetWel! fields removes any VOC's that are present in the untreated raw water in these areas. Water delivered to customers is sampled quar- terly to ensure the treated water meets or exceeds all state, federal and Acton Water District safe drinking water standards. Current Extent of Groundwater Contamination The nature and extent of contaminated groundwater at the Site has been defined and documented in the 2005 Public Re- view Draft Remedial Investigation Report. Figure 3 depicts the current extent and concentrations of vinylidene chloride (VDC or I, I-dichloroethene). VDC is the most widespread contaminant at the site. As of 2008,VDC levels in groundwater at the site ranged from less then 7 to S50 parts per billion.The maximum contaminant level that EPA considers safe forVDC in groundwater is 7 parts per billion. Figure 3 shows the maximum VDC concentrations regardless of depth, as of fell of 2008. Northeast Area Schedule installation of the Northeast Area treatment system is expected to occur between June 2009 and October 2009, Monday through Friday during normal business hours. After being field tested, the North east Area system wilt operate for a period of approximately 3 to 5 years. Prior to giving final approval, EPA and MassDEP will review the data from the system operations and confer with the local stakeholder's before the Northeast Area system can be shut down. History of Site Operations The W.R. Grace Superfund site located off Independence Road in South Acton has been used for industrial purposes since the 1800s. After purchasing the property in 1954,W.R, Grace & Co. (Grace) produced a variety of latex and rubber-based products as well as cellulose battery separators.The waste products from these manufacturing opera- tions were disposed of on-site in unlined lagoons. In 1980, all on-site waste disposal operations at the facility ceased. In early 1982,Grace discontinued its organic chemi- cal operations at the South Acton site which generated the bulk of the site wastes. How We Got Here Record of Decision and Statement of Work On September 30, 2005, EPA, with concur- rence from the MassDEP,selected and docu- mented the third and final cleanup plan for the Site in a Record of Decision (ROD).The ROD addresses clean-up of contaminated groundwater, sediment and soil in Sinking Pond and the North Lagoon Wetlands that pose a potential unacceptable risk to human health and/or the environment. Details of the ROD can be found at: www.epa.gov/regionO I /superfund/sites/ graceacton/237033.pdf In August 2006, EPA, MassDEP and W. R. Grace entered into a legally binding agree- ment known as the remedial design/reme- dial action Scope ofWork (SOW), under a Consent Decree previously approved by the court. The SOW, which was finalized in August 2006, outlines the framework for the final cleanup activities and includes schedules, engineering designs and construc- tion requirements that Grace must fulfill in order to complete the final cleanup actions at the site. More specific details of the SOW may be found at: www.epa.gov/regionl/superfund/ sites/graceacton/256924.pdf Contacts: EPA Contacts: Derrick Golden USEPA New England, Region I Remedial Project Manager 617-918-1448 golden.derrick@epa.gov Sarah White USEPA New England, Region I Community Involvement Coordinator 617-918-1026 white.sarah@epa.gov State Contacts: Jennifer McWeeney - MassDEP Project Manager 617-654-6560 Jennifer.Mcweeney@state.ma.us Acton Contacts: Doug Halley Acton Board of Health Health Director 978-264-9634 dhalley@town.acton.ma.us Matthew Mostoller Acton Water District (AWD) Environmental Compliance Manager 978-263-9107 Matt@actonwater.com Mary Michelman Acton Citizens for Environmental Safety (ACES) 978-263-7370 msmichelman@comcast.net United States Environmental Protection M * Agency ------- |