PHASE IV - REMEDY IMPLEMENTATION PLAN FORMER VARIAN FACILITY SITE 150 SOHIER ROAD BEVERLY, MASSACHUSETTS

Transcription

1 PHASE IV - REMEDY IMPLEMENTATION PLAN FORMER VARIAN FACILITY SITE 150 SOHIER ROAD BEVERLY, MASSACHUSETTS MADEP SITE NO TIER IB PERMIT NO. P23730 IT Corporation Project No December 2001 IT Corporation Prepared by: IT Corporation Reviewed by: Eric E. Vining Project Engineer Timothy W. Kemper, PE, LSP Licensed Site Professional Lawrence J. Nesbitt, PE Senior Engineer Richard W. Lewis, CPG Vice President, Remedial Technology Karen L. Brody, PE Project Manager D:\Phase 4 Final.doc

2 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page i CONTENTS 1.0 INTRODUCTION Statement of Purpose Objective SITE BACKGROUND AND PREVIOUS ACTIVITIES Former Varian Property Description On-Going Remedial Measures Site Regulatory and Investigative History PHASE IV REMEDY IMPLEMENTATION PLAN (310 CMR (3)) Relevant Site Contact Information (310 CMR (3)(a)) Responsible Party Licensed Site Professional Owner and Operator Engineering Design (310 CMR (3)(b)) Remedial Action Goals Significant New Information Not Previously Submitted Disposal Site Maps Description of Environmental Media to Be Treated Description of Selected Remedial Action Alternative In Situ Oxidation with Permanganate Addition Conceptual Implementation Plan Relevant Design and Operation Parameters Identification of Site-Specific Characteristics Affecting Design Permanganate Addition Design Criteria Permanganate Type Permanganate Addition Locations/Method Permanganate Volumes Permanganate Addition Procedures Treatment Efficiency Design Control Features Waste Management Waste Soil Management Wastewater Management Environmental Impact Mitigation Measures Construction Inspections and Monitoring Construction Plans and Specifications (310 CMR (3)(c)) Plans and Specifications Utility Clearances Application and Monitoring Points Well and Infiltration Gallery Materials and Details Chemical Solutions Chemical Handling and Storage Application and Monitoring Equipment Equipment Schematics Schedule for Design and Installation Activities Operation, Maintenance and/or Monitoring (310 CMR (3)(d)) Person(s) Conducting Operation, Maintenance and/or Monitoring General Operating Procedures Shutdown and Emergency Procedures Control System Emergency Procedures... 30

3 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page ii CONTENTS (continued) Groundwater Monitoring and Sampling Baseline Groundwater Sampling Post-Addition Groundwater Monitoring and Sampling Health and Safety Plan (310 CMR (3)(e)) Federal, State or Local Permits and Approvals (310 CMR (3)(f)) Property Access Issues (310 CMR (3)(g)) AS-BUILT CONSTRUCTION REPORT (310 CMR ) FINAL INSPECTION REPORT AND PHASE IV COMPLETION STATEMENT (310 CMR , 310 CMR ) PUBLIC INVOLVEMENT ACTIVITIES (310 CMR ) REFERENCES Tables 1. Calculation of Travel Velocity for Permanganate Application Areas 2. Permanganate Application Summary 3. Sampling Summary 4. Permanganate Application and Observation Wells, Building 3 Source Area 5. Permanganate Application and Observation Wells, Building 6 Source Area 6. Permanganate Application and Observation Wells, PSL 10 Area 7. Permanganate Application and Observation Wells, Tozer Road North of 128 Area 8. Permanganate Application and Observation Wells, Tozer Road South of 128 Area 9. Permanganate Application and Observation Wells, 31 Tozer Road Area 10. Permanganate Application and Observation Wells, Longview/Hill Street Area Figures 1. Site Location Map 2. Site Plan 3. Estimated Distribution of Total VOC Concentrations in Shallow Overburden Aquifer 4. Estimated Distribution of Total VOC Concentrations in Deep Overburden Aquifer 5. Estimated Distribution of Total VOC Concentrations in Bedrock Aquifer 6. Location of Potentially Productive Aquifer and Potential Source Locations 7. Treatment Areas for Chemical Oxidation 8. Building 3 Source Treatment and Observation Area 9. PSL 10 Treatment and Observation Area 10. Tozer Road North of 128 Treatment and Observation Area 11. Tozer Road South of 128 Treatment and Observation Area Tozer Road Treatment and Observation Area 13. Longview/Hill Street Treatment and Observation Area

4 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page iii Appendices A. Permanganate Usage Estimates B. Proposed Project Schedule C. Construction Plans and Specifications D. Health and Safety Plan - Permanganate Addendum, Material Safety Data Sheets and Material Properties E. Job Safety Analysis Worksheet and General Operating Procedures F. Manufacturers Equipment Specifications G. Public Involvement Notices

5 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page INTRODUCTION Varian Medical Systems, Inc. (Varian) retained IT Corporation (IT) to prepare a Phase IV Remedy Implementation Plan (Phase IV Plan) for the impacts from the former Varian facility located at 150 Sohier Road, Beverly, Massachusetts (Site) (Figures 1 and 2). This Phase IV Plan has been prepared in compliance with the Massachusetts Contingency Plan (MCP, 310 CMR ). IT completed and submitted a Draft Phase IV Remedy Implementation Plan report for the above referenced Site on September 4, Varian held a public meeting on October 11, 2001 to discuss and answer any questions regarding the Phase IV report and conducted a 51-day public comment period. Responses to written comments on the Phase IV report and questions and comments received at the public meeting were addressed in accordance with the Public Involvement Plan (PIP) for the Site. A summary of the comments and responses from the meeting and a summary of written comments and responses were submitted under a separate cover. The report includes the information set out in the MCP requirements for a Phase IV Remedy Implementation Plan, as presented in 310 CMR (3). The sections of this report are as follows: Section Introduction Section Site Background and Previous Activities Section Phase IV Remedy Implementation Plan Section As-Built Construction Report Section Final Inspection Report and Phase IV Completion Statement Section Public Involvement Activities Section References 1.1 Statement of Purpose The purpose of this Phase IV Plan is to document the design, construction and implementation plans for the selected remedial action for the Site in accordance with the MCP (310 CMR ). In situ oxidation of volatile organic compounds (VOCs) in soil and groundwater is the selected remedial alternative for the Site. 1.2 Objective The objective of the in situ oxidation remedial alternative is to reduce chlorinated solvent concentrations detected in soil and groundwater in order to achieve a level of No Significant Risk, as defined by the MCP. The anticipated outcome of implementation of the remedial action alternative selected in the Phase III Remedial Action Plan (IT, 2001) is to progress to Phase V (operation, maintenance and monitoring of the remedial action) and subsequently achieve a Response Action Outcome (RAO) and Site closure.

6 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 2 The Phase II concluded that a condition of No Significant Risk exists currently at the Site. However, a potential risk to human health may exist in the future in the area located north of Route 128 where groundwater is classified as GW-1 and may be used as a future drinking water source. The primary focus areas for remedial actions are those areas where VOCs are present and have the potential to migrate into the GW-1 area. These areas include identified contaminant source areas located at the former Varian facility and downgradient areas containing VOCs that may contribute to the presence of VOCs in the GW-1 area. These areas are: PSL 5 Potential former septic tank PSL 6 Potential former septic tank/leach field PSL 9 Inspection pit near Building No. 3 PSL 11 Building No. 3 laboratory PSL 12 Potential former lime pit The area located just north of the former Varian facility and Route 128 (16 Tozer Road) The area located along Tozer Road just north and south of Route 128 Remediation will be performed in the areas listed above in order to meet drinking water standards in the GW-1 area and achieve a Permanent Solution so that a Class A RAO can be submitted under the MCP. No other areas of the Site are required, under the MCP, to be remediated to achieve a level of No Significant Risk. However, Varian is adopting an extremely conservative approach and will conduct additional remedial actions in other areas in order to reduce VOC concentrations. The other areas where Varian intends to conduct additional cleanup activities include: Longview/Hill Street area PSL Tozer Road area Chemical oxidation of the identified source areas and downgradient areas has been selected as the most appropriate remedial response for the Site. Varian will implement this technology in the contaminant source areas and multiple downgradient locations to destroy VOCs, thereby reducing concentrations of VOCs in groundwater and surface water at the Site. This remedial technology has been successfully used at numerous other sites and is expected to reach the cleanup goals more quickly than the other remedial alternatives evaluated. This remedial technology has been proven to be successful in the most contaminated area of the Site through field pilot testing activities and will require minimal disturbance of the Site and surrounding properties. It is anticipated that the selected remedial alternative will substantially reduce VOC concentrations across the Site in groundwater and surface water and ultimately achieve the remedial objective of attaining Massachusetts Drinking Water Standards in the GW-1 area located north of Route 128. The selected remedial alternative is expected to achieve a Permanent

7 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 3 Solution at the Site. This Permanent Solution is anticipated to result in attainment of the desired cleanup levels and achieve a condition of No Significant Risk. 2.0 SITE BACKGROUND AND PREVIOUS ACTIVITIES 2.1 Former Varian Property Description Varian s former facility is located at 150 Sohier Road, Beverly, Essex County, Massachusetts. The property at 150 Sohier Road has the Universal Transverse Mercator coordinates of North 4,715,075 meters and East 345,475 meters, Longitude 70 o 52' 57" West; Latitude 42 o 34' 28" North. Figure 1 identifies the location of 150 Sohier Road and the surrounding area. The former Varian facility is located on approximately 24 acres of land, with eleven industrial buildings totaling approximately 200,000 square feet in area. Approximately 20 percent of the 24 acres of land is covered by the facility buildings; another 50 percent is covered by asphalt paved areas, and the remaining 30 percent is either undeveloped or covered with grass. Ten industrial buildings are located at 150 Sohier Road, and one is located at 28 Tozer Road (Building L-1). In addition to the eleven industrial buildings Varian utilized, there are also two former residential structures located near the western boundary between 150 Sohier Road and 30 Tozer Road. One building was formerly used by Varian as an employee credit union and the other as a reference library. Communications & Power Industries, Inc. (CPI) acquired the facility in The southern portion of the facility contains an open field and a paved parking area. The central portion of the facility contains a building complex consisting of Buildings 5, 5A, 8 and 10. North of this complex is a flat paved parking area. To the northwest is another building complex consisting of Buildings 1, 2, 3, 4 and 6. Northeast of Buildings 1, 2, 3, 4 and 6 is CPI s wastewater treatment plant and Varian s groundwater extraction and treatment system (Building 9). Southwest of Buildings 1 and 2 are Buildings 7 and 7A. Salem Water Works Road, located east of Building 7, traverses the property at 150 Sohier Road from the south to the north. Varian eventually leased the 28 Tozer Road Building L-1 to ST Olektron, which manufactured radarbased solid state equivalents. When CPI acquired the former Varian property, the lease with ST Olektron continued. Subsequently, ST Olektron was acquired by Signal Technology, and CPI sold this building and property to Signal Technology in Presently, CPI maintains the use of Buildings 1 through 6, 8, 9, and 10 and one of the former residential structures. CPI recently sold Buildings 7 and 7A. CPI also leases one of the two former residential structures to New England BioLabs for use as temporary visitor housing. With the exception of the sale of the properties at 28 Tozer Road and Buildings 7 and 7A, the property boundaries at 150 Sohier Road and adjacent parcels of land have not changed since Varian sold the property in 1995.

8 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 4 The Site topography gently slopes from the southern portion of 150 Sohier Road at approximately 88 feet above Mean Sea Level in elevation to the northern portion of the facility property near Route 128 at approximately 69 feet in elevation. At the southwest, west and northwest property lines, a steep embankment of approximately 30 feet slopes from Salem Water Works Road to the abutting properties along Tozer Road. The facility at 150 Sohier Road is predominantly covered with buildings and paved parking lots. An open grassy field is located on the southeast portion, and small strips of grass and landscaped areas surround some portions of the buildings and parking areas. Small trees and shrubs are located along the property line abutting Sohier Road and the embankment along the southwest, west and northwest property line. 2.2 On-Going Remedial Measures A groundwater extraction and treatment system has been in operation at the former Varian facility since The remediation system is located in Building 9 near the primary former source area at 150 Sohier Road. The system is designed to remove VOCs from groundwater and to reduce dissolved chemical migration. Since 1992, over 6,600 pounds of VOCs have been removed by this system. The groundwater treatment system draws water from six extraction wells (RW-1 through RW-5 and MW-17) located in the northeast part of 150 Sohier Road, as shown on Figure 2. A summary of the extraction well screen depths and average extraction well yields is presented below. Actual extraction rates vary seasonally. Extraction Well Characteristics Well Identification Screened Interval Average Extraction Well Yields (feet below ground) (gallons per minute) RW-1/MW RW RW RW RW MW-17/RW Groundwater is pumped from six extraction wells to a groundwater treatment building through doublewalled piping. The extracted groundwater is routed to an equalization tank that also serves as a settling/separation tank. Following settling, caustic soda is added to increase the ph. The groundwater is then treated through a primary air stripper and a polishing air stripper arranged in series. The treated water then passes through a flow meter and ph meter prior to discharge to the Unnamed Stream under

9 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 5 conditions of a National Pollutant Discharge Elimination System permit exclusion from EPA dated May 31, VOCs in the off-gas from the first air stripper are removed with vapor phase activated carbon, which is regenerated by steam on-site. The VOCs recovered during carbon regeneration are drummed and properly disposed of off-site. The performance of the remediation system is reported regularly to the Massachusetts Department of Environmental Protection (MADEP) in Release Abatement Measure (RAM) status reports, in accordance with the MCP. 2.3 Site Regulatory and Investigative History Investigations at the former Varian facility began in 1985 following the removal of a 3,000-gallon underground storage tank (UST) used to store spent acetone. As a result of the apparent release at the former acetone UST location, the MADEP notified Varian in a letter dated December 3, 1985 that Varian was responsible for investigating and assessing the source and extent of the acetone release. Environmental assessment activities continued at 150 Sohier Road in May 1986 when Varian installed four groundwater monitoring wells to evaluate the integrity of on-site fuel oil USTs. Sampling and analysis of groundwater from these wells indicated the presence of VOCs, which was reported to the MADEP by Varian in a letter dated October 3, The notifications resulted in the Site being placed on the Massachusetts List of Confirmed Disposal Sites and Locations To Be Investigated on January 15, 1987 (CHES, 1993). In response to the detection of VOCs in 1986, Varian retained Clean Harbors Environmental Services (CHES) to evaluate Site conditions. The results of the CHES investigation were presented in the Preliminary Environmental Site Evaluation, dated July 2, 1987 (CHES, 1993). The Preliminary Environmental Site Evaluation recommended additional investigation, which was conducted from August 1987 through March The investigations identified the presence of VOCs in groundwater in the northeast portion and the southeast area of the property at 150 Sohier Road. These results were reported in the Final Environmental Site Evaluation & Proposed Remedial Study, dated May The study also described several options to remediate the Site (CHES, 1993). As a result of the recommendations in the 1988 report, five additional groundwater monitoring wells were installed in the northeast portion of the property and tested to evaluate their potential performance as extraction wells. This work was completed and reported in a Phase III - Development of Remedial Response Alternatives report dated July 1989, with a remedial treatability study that was performed to determine the best method for remediating the VOCs dissolved in groundwater. Based on the results of the Phase III study, air stripping was recommended as the most suitable technology for treating Site groundwater (CHES, 1993b). The construction and start-up of the designed remedial system were proposed as an Interim Measure (IM) in a letter to the MADEP, dated February 26, The MADEP approved the IM request in letters dated May 9 and June 26, After approval of the IM, the treatment system was constructed and began operation in May 1992.

10 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 6 Varian submitted a Waiver of Approvals application, Interim Site Classification Form and preliminary assessment form to the MADEP in August In February 1993, the MADEP issued a Waiver of Approvals (Waiver) for the Site and, in March 1993, classified the Site as a non-priority site (CHES, 1993). The Site was also designated as a Public Involvement Plan (PIP) site in March 1992, following the submittal of a petition to the MADEP in February 1992 requesting public involvement. Notification of the availability of key documents for the Site has been provided to key petitioners and others, and copies of those documents have been placed in a local information repository (the Beverly Public Library, 32 Essex Street) and the Beverly Board of Health, 90 Colon Street, Beverly, MA.). Fact sheets have been prepared and distributed at key phases of the assessment work in accordance with the PIP process. To further identify the nature and extent of VOCs at Varian s former facility, CHES conducted additional work. The results of this work were presented in the Phase IIA Comprehensive Site Assessment (CSA) report prepared by IT, dated November 7, This report identified 13 potential source locations (PSLs) associated with the Site (IT, 1994). On behalf of Varian, IT has conducted further site assessment activities, including investigation of the 13 PSLs as outlined in the Phase IIB Scope of Work (SOW) and 6 more PSLs identified in 1995, under the guidelines of a Waiver of Approvals and the Tier 1B Permit. Prior to the expiration of the Waiver in March 1998, Varian submitted a Tier IB Permit application to MADEP. The permit application stated that the response actions Varian had been conducting would continue under a RAM Plan. The MADEP approved the Tier IB application in a letter dated June 23, Tier 1B Permit Number P23730 was issued for the Site with an effective date of July 14, The final Phase II CSA report was submitted to MADEP in September The Phase II concluded that the primary chemicals of concern at the Site are chlorinated VOCs, particularly trichloroethene (TCE), tetrachloroethene (PCE), and 1,1,1-trichloroethane (TCA), which were historically used at the former Varian facility for degreasing operations. Five degradation products of TCE, PCE, and TCA are cis-1,2- dichloroethene (cis-1,2-dce), trans-1,2-dichloroethene (trans-1,2-dce), 1,1-dichloroethene (1,1-DCE), 1,1-dichloroethane (1,1-DCA) and vinyl chloride (VC); these degradation compounds have also been found in groundwater and surface water at the Site. The areal extent of dissolved VOCs in the groundwater generally increases with depth. For individual constituents, the plume is generally the smallest in the shallow overburden aquifer and increases in size and in concentration in the deep overburden aquifer and the bedrock aquifer. Estimated distribution of total VOC concentrations in the shallow overburden aquifer, deep overburden aquifer and bedrock aquifer are provided in Figures 3, 4 and 5, respectively. The Phase II concluded that a condition of No Significant Risk exists currently at the Site. However, a potential risk to human health may exist in the future in the limited area located north of Route 128 where groundwater is classified as GW-1 because it meets MADEP s definition of a potential future drinking water source. On September 21, 2000, Varian submitted to the MADEP a Phase III Remedial Action Plan (RAP) for the former Varian facility located at 150 Sohier Road, Beverly, Massachusetts. Since completing the Phase III RAP last September, Varian conducted additional testing of two remediation technologies to further evaluate and expedite cleanup actions at the Site. Varian subsequently submitted an Amended RAP that

11 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 7 presented the results of the testing and re-evaluated the cleanup alternatives in light of the new results. Two pilot tests showed that sodium permanganate could be effective in the treatment of both low and high concentrations of VOCs in groundwater at the Varian Site in both the overburden and bedrock aquifers. Therefore, Varian chose to evaluate this new information on the effectiveness of permanganate as a remedial alternative, and as a result of that evaluation, to amend the original RAP. The draft Amended RAP was distributed on May 31, 2001 for a public comment period that ended on July 30, 2001; the final Amended RAP was distributed on August 30, The Phase IV Remedy Implementation Plan was distributed on September 4, 2001 for a public comment period that ended on October 26, PHASE IV REMEDY IMPLEMENTATION PLAN (310 CMR (3)) The following sections address the Phase IV Plan requirements as listed in the MCP (310 CMR ). 3.1 Relevant Site Contact Information (310 CMR (3)(a)) Responsible Party The responsible party for submittal of this Remedy Implementation Plan is: Varian Medical Systems, Inc Hansen Way M/S F-095 Palo Alto, CA Ms. Denise Kato, contact Phone: (650) Licensed Site Professional The Licensed Site Professional responsible for submittal of this Remedy Implementation Plan is: Mr. Timothy W. Kemper, PE, LSP IT Corporation 88C Elm Street Hopkinton, MA Phone: (508) Owner and Operator The owner of the selected remedial action alternative is: Varian Medical Systems, Inc Hansen Way M/S F-095 Palo Alto, CA Ms. Denise Kato, contact

12 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 8 Phone: (650)

13 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 9 On behalf of Varian Medical Systems, Inc., the primary operator of the selected remedial action alternative is anticipated to be: Mr. Lawrence J. Nesbitt, PE IT Corporation 88C Elm Street Hopkinton, MA Phone: (508) Engineering Design (310 CMR (3)(b)) Remedial Action Goals The target cleanup levels for this Site are intended to be protective of human health, the environment, public welfare and safety and are based upon reasonable exposure scenarios under current and reasonably foreseeable future Site use. The Method 3 risk assessment included in the Phase II CSA concluded that No Significant Risk exists currently and in the future across the Site, with the exception of a potential future significant risk to human health in the area located north of Route 128 where groundwater is classified as GW-1. Therefore, this is the only area of the Site where concentrations must be reduced to achieve a level of No Significant Risk. Certain groundwater located north of Route 128 is currently classified as GW-1, due to the presence of a medium yield potentially productive aquifer. This area is shown on Figure 6. The Phase II risk characterization compared the concentrations of VOCs detected in groundwater monitoring wells in this area to applicable Massachusetts Drinking Water Standards. Applicable drinking water standards (target cleanup levels) for the VOCs of concern in this portion of the Site are listed below: tetrachloroethene = 5 Φg/l trichloroethene = 5 Φg/l 1,1,1-trichloroethane = 200 Φg/l cis-1,2-dichloroethene = 70 Φg/l trans-1,2-dichloroethene = 100 Φg/l 1,1-dichloroethene = 7 Φg/l 1,1-dichloroethane = 70 Φg/l vinyl chloride = 2 Φg/l Concentrations of PCE and TCE have exceeded their respective GW-1 standards in wells CL6-DO, CL6- BR, and BR-1. Therefore, it was concluded that a condition of No Significant Risk has not been achieved in this area of the Site. As long as groundwater in this area is classified as GW-1, and drinking water standards are exceeded, remedial efforts at the subject Site are necessary to achieve a condition of No Significant Risk.

14 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 10 This Phase IV Plan also includes cleanup of some areas where VOCs are present and there is No Significant Risk. VOC concentrations in groundwater in these areas will be reduced, to the extent feasible, to levels that achieve or approach background Significant New Information Not Previously Submitted As part of the on-going RAM activities, groundwater samples were collected from Site monitoring wells in June 2001 and November Results of the June 2001 sampling were presented in a RAM Status report submitted at the end of August Results of the November 2001 sampling will be presented in a RAM Status report to be submitted by the end of February During the summer of 2001, Varian conducted a residential indoor air sampling program at the request of local officials and residents. The purpose of this work was to determine if volatile organic compounds (VOCs) detected in indoor air were associated with the plume from the Varian Site and, if so, whether they present any significant risk to any residents. Thirty-six homes in areas surrounding Varian s former facility were sampled during the testing program. Of these 36 homes, 16 (or 44%) are located over shallow groundwater impacted by VOCs associated with the former Varian facility. The sampling methods and evaluation were conducted consistent with state regulations and guidance developed by the MADEP. Evaluation of the data showed that, even for those chemicals for which MADEP has not published background levels, no VOCs detected in indoor air were from the Varian Site. Only three homes out of the 36 sampled had levels of VOCs detected above the published MADEP background concentrations, and those three homes are not located over shallow groundwater impacted by the VOCs detected in indoor air. Household products containing VOCs were present in these homes 1 at the time of sampling and are the likely source of the detected VOCs. The data collected during this study, including soil vapor and groundwater sampling results, were found to be consistent with earlier studies conducted by Varian in the area. The data support the conclusions of the CSA and findings of No Significant Risk from the Varian Site, and they support the selected remedial alternative (Phase III) and design of the remedial alternative (Phase IV). A description of the indoor air sampling and results was submitted to MADEP and city officials in October Disposal Site Maps A Site Plan depicting Site features is included as Figure 2. Estimated distributions of total VOC concentrations in shallow overburden, deep overburden and bedrock aquifers are depicted in Figures 3, 4 and 5, respectively. The potentially productive aquifer (GW-1 area) and potential source locations (PSLs) are depicted on Figure 6. A map showing the planned treatment areas at the facility and surrounding areas is included as Figure 7. 1 In addition, similar products were observed in all of the 36 homes participating in the study.

15 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page Description of Environmental Media to Be Treated VOCs have been detected in both the soil and groundwater at the subject Site. The primary focus for remedial actions is those areas where VOCs are present and have the potential to migrate into the potentially productive aquifer area (Figure 6), creating a potential future risk to human health if the groundwater were to be used for drinking. These areas include identified contaminant source areas located at the former Varian facility and downgradient areas containing VOCs that may contribute to the presence of VOCs in the GW-1 (Potentially Productive Aquifer (PPA)) area north of Route 128. The identified contaminant source areas at the former facility which may affect the GW-1 area are noted on Figure 6 and are listed below: PSL 5 Potential former septic tank near Building 3 PSL 6 Building 6 - Potential former septic tank/leach field PSL 9 Inspection pit near Building 3 PSL 11 Building 3 laboratory PSL 12 Potential former lime pit near Building 3 These PSL areas are herein referred to collectively as the source area. Some soils above the water table in these areas contain the target VOCs. These soils, as well as groundwater, will be treated using the selected remedial alternative. The downgradient areas containing VOCs that may contribute to the presence of VOCs in the potentially productive aquifer are listed below: The area located along Tozer Road just north of Route 128 (Tozer Road - North of 128) The area located along Tozer Road just south of Route 128 (Tozer Road - South of 128) Based on the groundwater flow patterns identified in the overburden and bedrock aquifers, groundwater in these two areas has the potential to migrate toward the north and northwest, toward the potentially productive aquifer. Remediation will be performed in the source areas and the areas north and just south of Route 128 in order to meet drinking water standards in the PPA and achieve a Permanent Solution so that a Class A RAO can be submitted under the MCP. Under the MCP, no other areas of the Site require remediation to achieve a level of No Significant Risk. However, Varian is adopting an extremely conservative approach and conducting additional remedial actions in other areas in order to respond to public concerns and reduce VOC concentrations in an expedited manner. The additional cleanup activity areas include: Longview/Hill Street area PSL 10 - Southwestern portion of 150 Sohier Road 31 Tozer Road area

16 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 12 The Longview/Hill Street area contains VOCs that have migrated from identified contaminant source areas. VOCs were transported to this residential area primarily through migration with groundwater through the bedrock formation and subsequent upward vertical migration to the shallow overburden aquifer. Remediation of the contaminant source areas at the former facility will eventually result in a reduction of VOCs in groundwater in this area. However, due to the large distance between the source areas and this residential area, reductions in VOC concentrations may take several years. Therefore, remediation will be conducted in this area to attempt to reduce VOC concentrations more quickly. PSL 10 is an area near the southwestern portion of Varian s former facility where waste liquids containing TCE, PCE and 1,1,1-TCA were historically disposed. Groundwater modeling of groundwater flow patterns at the Site indicate that groundwater in this general area moves vertically downward and to the west, toward the Unnamed Stream. Groundwater flow then follows the Unnamed Stream in a southerly direction. Remedial activities in the PSL 10 area will be conducted to attempt to expedite overall Site cleanup. The presence of VOCs in shallow groundwater in the area of 31 Tozer Road is thought to have resulted from past discharges at 150 Sohier Road into the Unnamed Stream, which was formerly located next to the 31 Tozer Road property. VOCs in groundwater in the area of 31 Tozer Road flow downgradient to the 39 Tozer Road property. Shallow groundwater at 39 Tozer Road is intercepted by that building s footing drains and discharges to Stream A. Remediation in the area of 31 Tozer Road area will reduce VOC concentrations in shallow groundwater in the vicinity of 31 Tozer Road, 39 Tozer Road and in Stream A. Thus, to summarize, the treatment areas addressed under this Phase IV Plan include: Summary of Treatment Areas Building 3 Source Area Building 6 Source Area PSL 10 Area Southwestern portion of 150 Sohier Road Tozer Road North of 128 Area Tozer Road South of 128 Area 31 Tozer Road Area Longview/Hill Street Area These treatment areas are depicted on Figure 7.

17 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page Description of Selected Remedial Action Alternative IT completed an Amended Phase III Identification, Evaluation and Selection of Remedial Action Alternatives (IT Corporation, August 2001). Based upon the detailed evaluation results, in situ oxidation of the source areas and downgradient areas using permanganate has been selected as the most appropriate remedial action alternative for the Varian Site. The alternative is expected to reach the cleanup goals and reduce VOC concentrations across the Site more quickly than the other alternatives evaluated. This remedial technology has been proven to be effective in the most contaminated area of the Site through field pilot testing and will require minimal disturbance at the former Varian facility and surrounding properties. The alternative is anticipated to achieve the remedial objective of attaining Drinking Water Standards in the GW-1 area located north of Route 128 in a reasonable period of time In Situ Oxidation with Permanganate Addition Permanganate is a common oxidant widely used in the water treatment industry to remove and precipitate dissolved metals and in the sewage treatment industry to treat sulfide odors. Permanganate will also react with and oxidize a wide range of common organic compounds relatively quickly and completely and without a significant generation of heat. In particular, permanganate reacts rapidly with the non-conjugated (i.e., non-aromatic) double bonds in chlorinated ethenes such as TCE, PCE, DCE isomers, and vinyl chloride. Permanganate does not react as effectively with the aliphatic single bonds in chlorinated ethanes, such as 1,1,1-TCA and DCA. 1,1,1-Trichloroethane and DCA don t currently exceed, and are not expected to exceed, drinking water standards in the GW-1 area. Because they do not pose a potential significant risk, cleanup of those compounds is not required. However, these single-bonded compounds can break down in both the presence and absence of oxygen in the subsurface. These compounds have been shown at the Site to be naturally breaking down and will continue to do so over time. 1,1,1-TCA is present in groundwater primarily in the immediate vicinity of Varian s former facility, at relatively shallow depths. The two main breakdown products of 1,1,1-TCA, 1,1-DCA and 1,1-DCE, are observed over most of the total VOC plume area, indicating that breakdown of 1,1,1-TCA is occurring. Permanganate is relatively stable and does not quickly decompose. Thus, a residual level of permanganate will remain in a groundwater system following addition. This is a benefit because it allows diffusion of the permanganate and a longer residence time to react with contaminants that desorb from the soil. Degradation products generated through oxidation of chlorinated ethene compounds include carbon dioxide, manganese oxide (a black precipitate/solid) and soluble ions (K +, Na +, Cl). The ions rapidly form insoluble salts which remain in the soil at concentrations that were not shown (during pilot testing) to create a groundwater quality problem. Both the carbon dioxide gas and the chloride produced in the reaction are diluted and dissipate harmlessly in the subsurface. The ph of the reaction is dependent on the type of chlorinated ethene being oxidized, but remains close to neutral (as seen during pilot testing) at this Site.

18 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 14 The balanced chemical equations for sodium permanganate oxidation of TCE (the predominant contaminant at the Site) are: Oxidation of TCE by NaMnO 4 : 2NaMnO 4 + C 2 HCl 3 (TCE) ---> 2CO 2 + 2MnO 2 + 2Na + + 3Cl - + H + In situ oxidation is a chemical reaction. The effectiveness of treatment depends on three factors: the kinetics of the reaction between the permanganate and the contaminant, the contact between the oxidant and the contaminant(s), and competitive reactions of permanganate with other reduced/oxidizable species. If the contaminant being targeted for in situ chemical oxidation is reactive (i.e., chlorinated ethenes) and sufficient oxidant has been added to overcome the demand from other reduced species, the limiting factor to the successful application of in situ oxidation is the transport of the oxidant to the areas of contamination, not the reaction itself between the permanganate and the contaminant. The oxidation of TCE and DCE by permanganate is very rapid. If the permanganate contacts the contaminant, it will react. IT s field experience has shown that significant oxidation can be observed in as little as a few hours after addition. By contrast, travel times for the permanganate to migrate away from the addition point may be on the order of a day to months, depending on the rate of groundwater flow. The use of permanganate as a remedial technology has been well documented in seminars, conferences and peer-reviewed journals in recent years since its use has become more routine. IT has implemented permanganate applications in Alabama, California, Connecticut, Florida, Kansas, Louisiana, Massachusetts, Maine, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Texas and Australia with successful remediation results Conceptual Implementation Plan Permanganate will be applied as a solution to the subsurface at the Site. The permanganate will destroy the VOCs with which it comes into contact in both the soil and groundwater. Unused permanganate and treated groundwater will flow to nearby downgradient locations and continue to reduce VOC concentrations in groundwater. Natural processes of attenuation and biodegradation will also continue to further reduce VOC concentrations in groundwater over time. Cleanup of shallow groundwater across the Site in both source areas and downgradient locations will also result in reductions in VOC concentrations in surface water bodies that receive water from the shallow aquifer. The type and method of injecting permanganate are determined by the depth and concentrations of the targeted VOCs and hydrogeologic characteristics of the application area. In those areas where the VOCs were historically discharged at the surface, the impacted soils above the water table, as well as the groundwater below will be targeted with shallow horizontal wells and trenches. In areas where VOCs have migrated vertically downward, permanganate will be applied through deeper vertical injection wells. In areas with lower VOC concentrations at shallow depths, shallow wells and Geoprobe direct push injection will be used. Varying the injection methods to place the permanganate in close proximity to the targeted VOCs will result in a more effective and timely cleanup.

19 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 15 The permanganate solution is relatively stable and generally consumed only through reaction with the contaminant or naturally occurring minerals, such as iron and manganese. The hydrogeologic characteristics of the aquifers at the Site were used to determine the amounts of permanganate to add in the treatment areas, the number of application points, the expected cleanup times, and the monitoring frequency. The results of this analysis are summarized in Table 1. A detailed description of the design parameters for the treatment system is included in Section Application of the permanganate will occur in steps, each carefully monitored for the response of the environment. Monitoring results will be reviewed to substantiate calculated demand and anticipated subsurface characteristics, or identify refinements warranted for subsequent applications. This is described in further detail in Section Relevant Design and Operation Parameters This section presents relevant design and operation parameters, as required by 310 CMR (9) and 310 CMR (3)(b)(6). This section includes the following information: Identification of Site-Specific Characteristics Affecting Design Permanganate Addition Design Criteria (type, location, volume, application method) Permanganate Addition Procedures Expected Treatment Efficiency Identification of Site-Specific Characteristics Affecting Design Site-specific characteristics affecting design of the remedial action have been identified for each of the seven treatment areas. The following table identifies, by treatment area and lithological unit, the Sitespecific characteristics and the corresponding design feature incorporated into the remedial solution. Site-Specific Characteristics Affecting Design Treatment Area Injection Area Lithology That May Affect Design Shallow Overburden (saturated & unsaturated zones) Site-Specific Characteristic Design Feature Building 3 Abandoned outfall pipe Video inspect interior of pipe for residual waste and location of potential leaks; screen soils adjacent to path of pipe; treat or remove impacted soils; remove or grout pipe (see explanation below). Shield conduits and/or apply permanganate below depth of conduits; hand or vacuum excavate to depth of conduits; plug abandoned conduits to control dispersion. Monitor wells between application points Many subsurface utilities Seasonal stream

20 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 16 Site-Specific Characteristics Affecting Design Treatment Area Building 6 PSL 10 Tozer Road North of 128 Tozer Road South of Tozer Road Longview - Hill Street Injection Area Lithology That May Affect Design Shallow Overburden Overburden (saturated & unsaturated zones) Site-Specific Characteristic Low permeability soil Impacts beneath active building and utilities Low permeability soil Many subsurface public utilities (former public way Salem Water Works Road) Low permeability soil Design Feature and stream; pace application rate to allow multiple monitoring events over time before total prescribed volume of permanganate is added. Apply concentrated oxidant to minimize hydraulic loading. Install horizontal application wells beneath building from building exterior (exterior grade is below slab grade) to minimize business impacts. Apply concentrated oxidant to minimize hydraulic loading. Shield conduits or apply permanganate (oxidant) below depth of conduits; hand or vacuum excavate to depth of conduits. Extend application period to reduce volume per application. Deep Overburden Unnamed Stream Initiate treatment with deep application only; monitor shallow wells and stream frequently for color change; limit application volumes. Deep Overburden Bedrock Shallow Overburden Deep Overburden High permeability; upward vertical hydraulic gradient Weathered rock; relatively high VOC concentrations upgradient from application area High permeability & downgradient footing drains to storm outlet Historic fill area; stream routed through long culvert End of plume Apply into bedrock and deep overburden; monitor triplet monitoring wells. Apply into two bedrock and two deep overburden wells; treat upgradient areas. Trial permanganate application with 4% of projected dose; monitor wells between application points and footing drains; spread application over three years to reduce volume injected per event. Trial permanganate application with 10% of projected dose; assess non-voc organic demands of matrix; monitor to confirm no oxidant breakout into culvert or stream Up to three annual applications to address potential continued migration from

21 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page 17 Site-Specific Characteristics Affecting Design Treatment Area Injection Area Lithology That May Affect Design Site-Specific Characteristic Design Feature upgradient VOC impacts. Limit permanganate application volumes to avoid potential migration to stream or basement sumps; inject away from stream and homes. Neighborhood area One of the site-specific characteristics affecting the design is the presence of an abandoned outfall pipe at Building 3. An abandoned underground drain line reportedly exists from the inspection pit outside of Building 3 (PSL 9) to the Unnamed Stream. Wastewater containing acids, cyanides, and solvents may have been discharged from this area to the Unnamed Stream north of Building 3 prior to the installation of the wastewater treatment system in This drain line, and perhaps the area surrounding the drain line, will require additional remedial measures prior to oxidant application. The following activities will be conducted to evaluate and address, if necessary, VOC impacts from this drain line: Attempt to locate the discharge end of drain pipe; If located, ensure downstream end of pipe is sealed; Inspect interior of pipe for evidence of open joints, cracks, blockages and/or remaining liquids/solids; Evaluate need for characterization of soils surrounding the pipe; Characterize soil surrounding pipe, if necessary; Clean pipe, if necessary; Grout pipe; Properly characterize and dispose of materials removed from the pipe; Collect soil samples and screen for VOCs in soils surrounding the pipe; and Evaluate need and feasibility of treatment or removal of impacted soils surrounding the pipe, considering proximity to utilities and Unnamed Stream Permanganate Addition Design Criteria The design criteria for permanganate addition included the determination of permanganate type, permanganate addition locations/method, and permanganate volumes. These criteria are outlined below and presented in detail in the construction plans and specifications section (Section 3.3). Table 2 summarizes the addition program by treatment area, including treatment area size, characteristics and assumptions; permanganate demand requirements; application and observation well installation and permanganate application volume and schedule.

22 Former Varian Facility Site, 150 Sohier Road, Beverly, MA, DEP RTN , Tier 1B Permit No. P23730 Page Permanganate Type Sodium permanganate was selected for use in all areas, as it is available in a concentrated form (40% solution), minimizing the volume of solution to be added and the corresponding time required (including potential disruption to business operations) to complete the addition Permanganate Addition Locations/Method Results of the subsurface investigation, oxidation pilot testing and pump testing were used to determine the locations for permanganate addition at the Site. The pilot tests and pump tests provided information on the amount of permanganate that can be applied to a single injection location and the distance the permanganate is likely to move from the point of injection. This information and the dissolved VOC concentration data were used to calculate the number of injection locations necessary in each treatment area. The permanganate addition locations are shown on Figures 8 through 13 and are summarized in Tables 4 through 10. Permanganate will be applied to the subsurface in the treatment areas through existing and new application wells and monitoring wells (the table below summarizes the application method at each treatment area). In addition, horizontal application wells, an infiltration gallery (horizontal slotted pipe in a gravel trench) and Geoprobe direct push injection will be used in selected areas. The method of application in each treatment area depends on the depth and concentrations of the targeted VOCs and the hydrogeologic characteristics of the area being treated. Where the VOCs were historically discharged to the ground at the former facility, permanganate will be applied using shallow horizontal wells and trenches (PSL 10 and Buildings 3 and 6). In areas with lower VOC levels in groundwater at shallow depths (Longview/Hill Street area and 31 Tozer Road area), shallow wells will be used, along with temporary injection points made using a hydraulically powered machine that pushes small-diameter rods into the ground with a minimum of disturbance to the surrounding area (Geoprobe direct push injection). In areas where higher levels of VOCs have moved deeper, permanganate will be applied through deeper vertical injection wells (areas north and south of Route 128 along Tozer Road). The permanganate addition method in each treatment area is listed below. Table 2 further details the number and type of addition points in each treatment area. Section 3.3 describes the specifications for these application points. PERMANGANATE ADDITION METHOD Treatment Area Application Method Building 3 Source Area Infiltration gallery; new and existing wells Building 6 Source Area Horizontal wells; new and existing wells PSL 10 Southwestern portion of 150 Sohier Infiltration gallery and new wells Road Tozer Road North of Route 128 New wells Tozer Road South of Route 128 Existing wells 31 Tozer Road Area New wells and temporary Geoprobe injection points