Permanent Solution Statement. and Immediate Response Action Completion Report Release Tracking Number

Transcription

1 Permanent Solution Statement and Immediate Response Action Completion Report Release Tracking Number Site Location Name: Easton Mobile Home Park 305 Turnpike Street Unit 173 Easton, MA Prepared for: Morgan Management, LLC 1080 Pittsford Victor Road Pittsford NY Prepared by: Common Sense Environmental, Inc. 38 Elm Street New Bedford, MA November 2014

2 Table of Contents RTN SECTION 1.0 INTRODUCTION... 1 SECTION 2.0 GENERAL SITE INFORMATION Property Description and Surrounding Receptors Site Description Potentially Responsible Parties Conducting Response Actions... 2 SECTION 3.0 RELEASE HISTORY AND CONCEPTUAL SITE MODEL Release History Conceptual Site Model... 3 SECTION 4.0 IMMEDIATE RESPONSE ACTION ACTIVITIES Immediate Response Actions Assessment Activities Soil Excavation Activities Subsurface Assessment Groundwater Recovery Events Site Restoration Groundwater Sampling and Analysis Vapor Intrusion Evaluation Substantial Release Migration Determination Critical Exposure Pathway Remediation Waste Management... 8 SECTION 5.0 NATURE AND EXTENT OF CONTAMINATION Soil Groundwater Contaminant Fate and Transport... 9 SECTION 6.0 REPRESENTATIVENESS AND DATA USEABILITY EVALUATION Representativeness Evaluation Data Usability Presumptive Certainty Data Quality Conclusion SECTION 7.0 RISK CHARACTERIZATION Identification of Applicable Soil and Groundwater Categories Soil Groundwater Identification of Contaminants of Concern... 12

3 RTN Identification of Exposure Points and Exposure Point Concentrations Exposure Point Concentrations and Method 1 Standard Comparison Activity and Use Limitations Characterization of Risk of Harm to Safety Risk to the Environment Risk Characterization Conclusion SECTION 8.0 PERMENANT SOLUTION STATEMENT General Feasibility of Restoration to Background SECTION 9.0 LSP CERTIFICATION LSP Certification SECTION 10.0 LIMITATIONS FIGURES Figure 1 Site Locus Figure 2 Site Plan Figure 3 MassGIS Priority Resources Map Figure 4A Groundwater Flow Plan July 2014 Figure 4B Groundwater Flow Plan September 2014 TABLES Table 1 Table 2 Table 3 Table 4 Table 5 Summary of Field Soil Screening Results Summary of Soil Analytical Results Summary of Groundwater Analytical Results Laboratory Analytical QC Evaluation Representativeness Evaluation

4 RTN APPENDICES Appendix A Appendix B Appendix C Appendix D Appendix E Soil Boring Logs Analytical Certificates Site Photolog Stage I Environmental Screening Evaluation Public Notification Letters

5 SECTION 1.0 INTRODUCTION Common Sense Environmental, Inc. (CSE) has prepared this Immediate Response Action (IRA) Completion Report and Permanent Solution Statement for Morgan Management, LLC (Morgan) in order to comply with the requirements of the Massachusetts Contingency Plan (MCP), 310 Code of Massachusetts Regulations (CMR) Morgan has completed the IRA as the owner of the 305 Turnpike Street property where a release of oil occurred from an above-ground oil tank that is neither owned nor controlled by Morgan. This report describes the response actions that have been completed and presents the data that supports the No Significant Risk determination and the filing of a Permanent Solution Statement at this time. This report along with BWSC Form 104 Permanent or Temporary Solution transmittal form and BWSC Form 105 IRA Completion Transmittal Form are being submitted electronically to the DEP through the edep filing system. SECTION 2.0 GENERAL SITE INFORMATION 2.1 Property Description and Surrounding Receptors The subject property consists of approximately 32 acres located at 305 Turnpike Street in Easton, Massachusetts, with UTM coordinates of N and E The parcel is the location of the Easton Mobile Home Park with approximately 122 residential mobile home lots. The subject property is bounded by residential properties located on Purchase Street to the north and by mobile home lots located on Turnpike Street to the east, south and west. A site locus plan is presented as Figure 1. The property is serviced by public utilities including electric, water and a package treatment plant septic system that services the Mobile Home Park. The property features are presented on Figure 2. According to the Bureau of Waste Site Cleanup (BWSC) site scoring map, presented as Figure 3, the subject property lies within a FEMA 100 year flood plain and a freshwater wetlands area designated as Area of Critical Environmental Concern (ACEC) within a Zone II Wellhead Protection Area (WPA) and a National Heritage Endangered Species Program (NHESP) Estimated Habitat of Rare Wildlife. The subject property is also located within 0.5 miles of an area designated as a certified vernal pool to the south and a potential vernal pool to the west at Gowards Corner. In addition, there is a freshwater wetlands (Little Cedar Swamp) located approximately one-half mile to the southwest. 2.2 Site Description The Site, as defined by the MCP, is Unit 173 within the Easton Mobile Home Park, and the location where a release of oil occurred. The lot is approximately 25 feet by 100 feet in size and is improved with a mobile home approximately 12 by 60 feet in size and a storage shed. Unit 173 is located in the northeastern portion of Easton Mobile Home Park. The mobile home is placed on a temporary foundation consisting of wooden footings erected on a concrete slab and two leveling jacks partially concealed by metal skirting. The mobile home was formerly heated November 2014 Page 1

6 by an oil fired boiler. Oil for the system was stored in a 275 gallon above ground storage tank (AST) located north of the mobile home. According to the mobile home owner, the AST and oil-fired boiler have not been used for approximately seven years. The name of the oil delivery company that provided oil for the AST is unknown at this time. Again, Morgan manages the mobile park and does not own or is responsible for the maintenance of the AST consistent with Massachusetts laws and regulations. The Site that is the subject of this PSS is depicted on Figure 2. Lot 173 borders a wetland area located on an off-site property located adjacent to the north side of the subject property. The wetland contains a stream channel cuts through the wetland area further to the west and feeds Cedar Swamp located approximately ½ mile to the southwest. 2.3 Potentially Responsible Parties Conducting Response Actions The potentially responsible parties associated with this release include the following parties: Mr. Jesse Engle, Mobile Home Owner 305 Turnpike Street, Unit 173 Easton, Massachusetts Mr. Robert Kircher, Manager Morgan Management, LLC 305 Turnpike Street Easton, MA Licensed Site Professional (LSP) for Morgan Management, LLC Cosmo Gallinaro Common Sense Environmental, Inc. 38 Elm Street New Bedford, MA SECTION 3.0 RELEASE HISTORY AND CONCEPTUAL SITE MODEL 3.1 Release History CSE understands that on March 10, 2014, a release of approximately 10 gallons of heating oil was discovered on the subject property as a result of a leaking AST. The release impacted surface soil on the subject property and an adjacent wetland area on two parcels of land owned by others. The release was reported to the Town of Easton Fire Department, who informed the Massachusetts Department of Environmental Protection (DEP). As a result of the release, the DEP assigned Release Tracking Number (RTN) and issued Notices of Responsibility (NORs) to both the Jesse Engle, owner of the mobile home, and Robert Kirchner, the manager of Morgan Management, LLC. DEP reported that the oil was observed on surface soil at the subject Site and the adjacent wetland. Oil was not observed on surface water in the stream or on November 2014 Page 2

7 the banks of the stream channel. As a result of the release, Global Remediation Services, Inc. (Global) was retained by Morgan Management, LLC to conduct an emergency response to stabilize conditions at the Site. Morgan Management LLC has retained Cosmo Gallinaro to serve as Licensed Site Professional (LSP) and to direct the response actions on their behalf at the Site. Morgan has now completed the response actions as described herein that have resulted in the attainment of a no significant risk determination. 3.2 Conceptual Site Model CSE believes that the release of oil from the abandoned AST migrated across the ground surface and based on topography into an adjacent wetland approximately 20 feet from the former tank. The release also migrated vertically and affected the shallow groundwater in the tank area as evidenced by an oil sheen on the groundwater surface. The oil therefore affected surficial and shallow subsurface soils in the upland and wetland and impacted groundwater with free-phase product in the form of an oil sheen. SECTION 4.0 IMMEDIATE RESPONSE ACTION ACTIVITIES 4.1 Immediate Response Actions In May 2014 CSE submitted a IRA Plan to the DEP through the edep filing system. The IRA Plan included the excavation of oil impacted soil, the pumping and containment of free phase heating oil and groundwater, off-site disposal of recovered groundwater and oil and assessment activities and wetlands restoration. The response actions were completed and are described below. 4.2 Assessment Activities Soil Excavation Activities On March 12, 2014, Global personnel conducted soil excavation activities at the Site. As petroleum-impacted soil was removed, the depth to Site groundwater was observed at approximately 8-inches below ground surface and that free-phase heating oil was noted as a sheen on the shallow groundwater. Global personnel utilized a vacuum truck to remove the floating product and to dewater the excavation area. The excavated soil was placed into 20 cubic yard (cy) roll-off boxes that were lined with polyethylene sheeting. At approximately one foot below ground surface, root material and stump debris was observed in the excavation area. The debris and oil impacted additional soil removal and were removed from the release area. At the completion of soil removal activities, CSE proceeded to collect five soil samples from the limits of the excavation area, which measured approximately fourteen by eleven feet in area with an approximate depth of two-three feet. The confirmatory soil samples November 2014 Page 3

8 were field screened for the presence of total organic vapors (TOVs) reported as parts per million per unit volume (ppmv/v) isobutylene using a photo-ionization detector (PID). The field screening results are presented in Table 1. The confirmatory soil samples were preserved, containerized and submitted to Test America for MADEP Extractable Petroleum Hydrocarbon (EPH) analysis. Once soil excavation activities were completed, Global personnel constructed a cut off system and containment area to trap groundwater within the impacted area. The cut off system consisted of high density polyethylene (HDPE) sheeting that was draped along the north, west and east sidewalls and keyed into the ground surface approximately 2 feet below the water table interface. Within the containment area Global constructed two 1-foot diameter groundwater recovery wells. The containment area was then backfilled with gravel and covered with polyethylene sheeting. At the completion of soil removal activities, approximately 15 cubic yards of petroleum-impacted soil and debris were removed from the Site and placed into two, 20 cy roll-off boxes that were removed from the mobile park on April 25, 2014 and transported under Uniform Waste Manifest to Waste Management Turnkey Landfill located in Rochester, NH. To facilitate excavation activities, 192 gallons of No. 2 fuel oil and petroleum-impacted groundwater were removed from the excavation area and transported under Uniform Waste Manifest for disposal to Tradebe located in Stoughton, MA. On May 5, 2014, additional soil excavation activities were conducted at the Site. The initial confirmatory sampling locations S-1 through S-4 were excavated along with impacted soils from the wetlands area. At the completion of excavation activities, additional confirmatory soil samples were collected from uplands and wetland soil from the excavation limits. The upland samples were designated as CS-1, CS-7, CS-8, CS-9, and CS-10 and the wetland soil samples were designated as CWS-2, CWS-3, CWS-4, CWS-5, CWS-6. The location of the samples are depicted on Figure 2. To facilitate excavation activities, an additional 890 gallons of No. 2 fuel oil and petroleum-impacted groundwater were removed from the excavation area and transported under Uniform Waste Manifest for disposal to Tradebe located in Stoughton, MA Subsurface Assessment On March 27, 2014, CSE personnel conducted subsurface site assessment activities with the assistance of Bronson Drilling. Five soil borings were advanced around the perimeter of the release area using Geoprobe direct push methods. Soil samples were collected in four foot intervals to a depth of eight feet below grade and screened for the presence of TOVs measured as isobutylene equivalents with a PID. Soil sample field screening results ranged from none detected to 2.9 ppmv/v TOVs. Confirmatory soil samples were preserved, November 2014 Page 4

9 containerized and submitted to Test America for MADEP EPH analysis. The results of the testing are discussed in Section 4.5. Four of the five soil boring locations were completed as 1-inch groundwater stand pipe monitoring wells constructed using 40-schedule polyvinyl chloride (PVC) slotted screen set at approximately 10.5 feet below grade connected to approximately 1.5 feet of riser and protected by a steel sleeve and locking monitoring well covers. The four ground water monitoring wells were developed upon installation. The soil boring logs/groundwater monitoring well completion reports can be found in Appendix A. Soil stratigraphy was observed to be fill material to approximate depths of three to six feet below grade underlain by native soils described as light brown and gray coarse to fine sands with traces of silt and/or gravel to depths of eight feet below grade. Depth to groundwater was observed at approximately feet below grade. No evidence of petroleum-impacts were noted in the soil samples collected during the subsurface assessment or in the groundwater generated during well development. 4.3 Groundwater Recovery Events On April 14, 2014 and on April 18, 2014, CSE personnel returned to the Site accompanied by representatives from Global to pump-out the two previously installed groundwater recovery wells. Upon the removal of the polyethylene sheeting, that was placed over the excavation area to minimize precipitation infiltration, and prior to pump-out activities, CSE personnel gauged each recovery well with use of a groundwater interface probe to determine whether a measurable thickness of free phase oil was present. No measurable thickness of oil was noted however an oil sheen was observed. Global personnel proceeded to pumpout the recovery wells with a vacuum truck. Each recovery well location was evacuated and allowed to recharge for approximately one hour and then evacuated for a second time. At the completion of pump-out activities, 530 gallons of petroleum impacted groundwater was removed on 4/14/14 and 580 gallons of petroleum impacted groundwater was removed on 4/18/14 from the release area. At the completion of groundwater pump-out activities, the polyethylene sheeting was re-secured over the release area. On April 23, 2014, CSE and Global personnel returned to the Site to pump-out petroleum-impacted groundwater from the two previously installed recovery wells. Upon completion of the pump-out activities, a total 532 gallons of petroleum-impacted groundwater was removed from the Site. Prior to departing the Site, new pieces of polyethylene sheeting were secured over the release area. At the completion of each groundwater recovery event, the petroleum-impacted groundwater was transported under Uniform Waste Manifest for disposal at Tradebe in Stoughton, MA. November 2014 Page 5

10 4.4 Site Restoration Upon collection of the confirmatory soil samples the excavation was backfilled to grade and the surface restored. In the upland portion of the property the surface was restored with loam and seed. In the wetlands portion of the property the impacted area was backfilled with specialized fill that contained loam and leaf compost and planted with native species for the settling as directed by Eco-Tec and approved by the Easton Conservation Commission. The restoration is described in the Stage 1 Environmental Screening Analysis that is presented in Appendix D. 4.5 Field Screening and Confirmatory Sampling and Analysis Throughout the excavation activities by CSE collected soil samples from the excavation to field screen the samples for total organic vapors with a PID. A summary of the field screening is presented in Table 1 and the locations of the samples are presented on Figure 1. Soil screening results at the completion of excavation activities were reduced to concentrations less than 11 ppmv with the exception of CWS-2 that revealed a headspace screening level of 31.3 ppmv. Confirmatory samples were collected from the excavation to verify the field screening and visual observations. The samples were submitted to Test America and the results are summarized on Table 2. The detected compounds consisted of: C 9 to C 18 aliphatic compounds were detected in three of the eleven samples from the limits of excavation and not detected in five samples collected from the soil borings. The detected concentration ranged from 5.5 to 22 milligrams to kilogram (mg/kg); C 11 to C 22 aromatic compounds were detected in five of eleven samples from the limits of excavation and two of five samples collected from the soil borings. The detected concentrations ranged from 6.6 to 71 mg/kg; and C 19 to C 36 aliphatic compounds were detected in three of eleven samples from the limits of excavation and 1 of five samples collected from soil borings. The detected concentrations ranged 5.6 to 13 mg/kg. 4.6 Groundwater Sampling and Analysis On April 1, 2014, CSE personnel returned to the Site to conduct a groundwater well elevation survey and to collect groundwater samples for laboratory analysis. Prior to sample collection, each well location was gauged using an oil/water interface probe to confirm the absence of non-aqueous phase liquid (NAPL) and to determine the depth to groundwater. NAPL was not identified in Site groundwater monitoring wells. The depth to Site groundwater was identified between feet below grade. The groundwater monitoring wells were purged of five well volumes of water and samples collected using low flow November 2014 Page 6

11 sampling techniques. Groundwater samples were containerized, preserved, and submitted to Test America for MADEP Volatile Petroleum Hydrocarbon (VPH) and EPH analysis. As noted on Table 3 there were no detectable concentrations of petroleum hydrocarbons in the samples. A review of the data indicated that although there were no detectable concentrations of petroleum hydrocarbons, the detection limit for 2-Methyl Naphthalene exceeded the Method 1 cleanup goal. Using the same sampling procedure, CSE returned to the property on June 24 and September 3, 2014 to sample groundwater. For these two sampling events, the analysis revealed no detectable concentrations of petroleum hydrocarbons and the detection limits were below the Method 1 cleanup goal for all compounds. As such the data confirmed the absence of 2-Methyl Naphthalene in the April sampling event. The groundwater data are presented on Table 3 and the analytical certificates for the September sampling event are presented in Appendix B CSE also completed a relative well head elevation survey. The gauging information coupled from the groundwater sampling events along with the survey information was used in an effort to determine the direction of groundwater flow across the Site. The results of the groundwater elevation survey revealed that groundwater consistently flows across the Site in a westerly direction toward the wetland area associated with Little Cedar Swamp. The direction of groundwater flow has been consistent over time and Figure 4A depicts the flow direction in July and Figure 4B depicts the flow direction in September Vapor Intrusion Evaluation The dwelling located on the property is a mobile home. Construction techniques for mobile homes include a sealed bottom that is isolated from the exterior. Due to the type of support structure for the mobile home, there is no continuous structure between the floor of the mobile home and the apron surrounding the mobile home has been removed over portions of the dwelling especially in the area of the release. As such, there is adequate ventilation to the area beneath the mobile home. In addition, headspace screening concentrations of less than 2 ppmv were noted in soil samples proximate to the mobile home during the May 2014 soil removal effort. Based on these factors CSE believes that indoor air is not a media of concern for the mobile home. 4.8 Substantial Release Migration Determination CSE has monitored conditions at the Site for conditions of Substantial Release Migration (SRM). Since the release did not impact surface water or significantly affect groundwater. In addition, there are no preferential utility pathways in the vicinity of the release. And the surface release has been remediated with no observed free phase oil or significant concentrations of petroleum hydrocarbons remaining in the wetland. As such, CSE does not believe that a SRM exists at the Site. November 2014 Page 7

12 4.9 Critical Exposure Pathway Following soil removal activities and restoration of the disturbed area, petroleum products have been removed from surface soil. This indicates that the surface soil on the property, the adjoining wetland and surface water are no longer significantly impacted by the released oil. In addition, as discussed in Section 4.7, vapor intrusion from residual contamination beneath the mobile home is not a complete exposure pathway. As such, CSE believes that a CEP is not present at the Site Remediation Waste Management A total of approximately 50 cubic yards of petroleum impacted soil were transported to Turnkey and a total of 2,725 gallons of oil impacted water was pumped from a holding tank and/or from the excavation on the property and transported to Tradebe of Stoughton MA under hazardous waste manifest. Disposal records were provided in the IRA plan submitted in May SECTION 5.0 NATURE AND EXTENT OF CONTAMINATION The source of the fuel oil release was a failed abandoned AST. As such the compounds of concern for this release consist solely of petroleum residuals from virgin fuel oil. In addition, the stream that runs through the adjoining wetlands was not impacted by the release of fuel oil at the Site so that surface water and sediment were not media of concern. Initial responders noted the absence of impacts in the stream. As a conservative measure, Global placed absorbent booms at multiple locations in the stream and oil staining was never noted on the booms during the response actions. The media of concern; therefore, for this release consist of soil and groundwater and are described below. 5.1 Soil Field screening and soil analytical results are presented in Tables 1 and 2, and corresponding sample locations are depicted on Figure 2. Residual petroleum impacted soil remain at the Site as documented by the analytical results over an approximate 600 square foot area to a depth of up to 4 feet below the ground surface. 5.2 Groundwater Following the completion of response actions that included the pumping of oil/groundwater, EPH and VPH fractions and target analytes were not detected in groundwater samples obtained from monitoring wells during the three sampling events. In addition after the pumping and recovery of free phase oil and groundwater from the impact area and the excavation and removal of oil impacted soil, no measurable petroleum product or oil sheen was observed in the excavation prior to backfill. The data therefore indicates that the groundwater was restored to a background condition. November 2014 Page 8

13 5.3 Contaminant Fate and Transport The residual compounds of concern at the Site consist of EPH range petroleum hydrocarbons. The vertical extent of impact is approximately 4 feet below the exterior grade. The area of surface impacts has been removed and restored and residual concentrations are consistently below the S-1 soil standards and covered with suitable fill. As such residual petroleum compounds have a negligible potential to migrate from the release area. The vapor intrusion evaluation outlined in Section 4.7 has demonstrated that migration to indoor air is unlikely. Since the compounds of concern are limited to petroleum residuals that naturally degrade, the concentration of residual petroleum hydrocarbons at the Site will decrease with time. SECTION 6.0 REPRESENTATIVENESS AND DATA USEABILITY EVALUATION 6.1 Representativeness Evaluation This section presents the evaluation of the Site data for representativeness pursuant to supporting the PSS presented herein in general accordance with DEP Policy #WSC , MCP Representativeness Evaluations and Data Usability Assessments. CSE s representativeness evaluation is presented on Table 5. The evaluation concludes that the soil and groundwater data obtained during and following the performance of IRA activities is considered to be sufficiently representative of site conditions to support the PSS documented herein. 6.2 Data Usability The data provided with this PSS was evaluated for usability in accordance with the MCP Presumptive Certainty As indicated in the laboratory reports supporting this PSS, the analytical laboratory has indicated that the conditions for Presumptive Certainty under applicable provisions of the MCP and DEP policy guidance were met. The laboratory provided the necessary Analytical Method Report Certification Forms, case narratives, and QA/QC data reporting; these were included in the laboratory reports provided with previous MCP submittals and in the laboratory reports provided in Appendix B Data Quality In an effort to verify that the data collected were suitable for use in site characterization, CSE reviewed the laboratory analytical report generated as part of the assessment activities. A summary table of analytical data usability obtained from this Site is provided as Table 4. This review included the report narrative, surrogate recovery results and the MCP Analytical Method Report Certification Form included in the data package. Surrogate recoveries for the specific November 2014 Page 9

14 analyses were reported as being within the range specified in the analytical methods. The certification form included with the analytical data package indicated that: Samples were received by the laboratory in a condition consistent with the Chain of Custody and consistent with required preservation methods. Analytical data met all the requirements for Presumptive Certainty, as described in Section 2.0 of the DEP document CAM VII A. CSE elected to have the analytical laboratory report only the target diesel PAH analytes since the release consisted of virgin fuel oil and EPH analysis in the initial assessment activities verified no other PAHs. All QC performance standards and recommendations for the specified methods were achieved, or data not meeting the appropriate performance standards were discussed in the case narrative. No QC performance issues were identified in the individual analyses performed. No performance issues meeting the DEP Rejection Criteria set forth in Appendix IV of DEP Policy #WSC were identified in all of the analytical data collected. In addition, CSE compared the laboratory reporting limits for all analytes with the applicable MCP Method 1 Risk Standards. The comparison indicated that the analytical data were sufficiently sensitive and usable in support of risk characterization and the PSS. EPH analysis were conducted and reported only the four diesel target PAHs at the request of CSE. Since the release consisted of virgin heating oil this request is appropriate to support the no significant risk determination Conclusion Based on the information provided in the laboratory analytical reports, the required QA/QC procedures were followed, and all performance/acceptance standards for the required QA/QC procedures were achieved unless otherwise noted. CSE reviewed the laboratory reports and opines that the soil and groundwater data collected at the Site: Meet the requirements for presumptive certainty as described in the DEP (WSC-CAM- VII A) policy for the acquisition and reporting of analytical data, Are acceptable for use in site characterization and conducting response actions under the MCP at this Site, and Are deemed usable in support of an LSP opinion for this Site. SECTION 7.0 RISK CHARACTERIZATION In accordance with 310 CMR , a Risk Characterization was performed to establish whether a level of "No Significant Risk" to health, safety, public welfare and the environment has been achieved at the disposal site for current conditions and any reasonable foreseeable use. Of the three Risk Characterization Methods available, Method 1for human health and Method 3 for Ecological Risk were selected and are applicable because: November 2014 Page 10

15 The contaminants of concern (COCs) remain in soil and are not likely to migrate at potentially significant concentrations to an environmental medium such as sediments, surface water, or ambient or indoor air; Promulgated MCP Method 1 Standards (310 CMR through ) exist for each COC; 100% of the confirmatory soil samples meet the method 1 cleanup standards; and There are no COCs that bioaccumulate; The release migrated to an adjacent wetlands and an ecological risk assessment was completed and is presented in Appendix D. This Method 1 Risk Characterization concludes that the Site poses No Significant Risk of harm to health, public welfare and the ecological risk assessment concluded that there is no current risk to the environment. As discussed previously, CSE believes that the sampling program documented in this report is sufficient to address and establish that the response actions were effective in abating the petroleum release and that no exposure point concentrations exceed the applicable MCP Method 1 Risk Standards. 7.1 Identification of Applicable Soil and Groundwater Categories Soil MassDEP has established categories S-1, S-2 and S-3 for soil pursuant to 310 CMR Soil categories are selected on the basis of the receptor's potential for exposure. Soil categories are determined by evaluating the accessibility of the soil in combination with the frequency and intensity of use by adults and children. Frequency of use is described as "high, low, or not present." Intensity of use is described as "high or low", and accessibility is described as "accessible, potentially accessible, or isolated." Under current and foreseeable Site activities and uses the applicable soil categories are determined as follows: Frequency of Use: Intensity of Use: Accessibility: The property is a residential property in Easton. Adult and Children Frequency of Use is considered High for current use and High for unrestricted future use. Current intensity of use is considered high for current and future use. The residual impacted soil located a in the landscaped area of a residential lot and in a wetlands area. For future current and future unrestricted use the soil would be considered accessible. Under current and future use is the applicable soil category S-1 applies Groundwater Site groundwater is categorized as follows. MassDEP has designated Categories GW-1, GW-2 and GW-3 for groundwater pursuant to 310 CMR These categories describe the potential for three types of exposure. One or more categories may apply to a given Site. November 2014 Page 11

16 Category GW-1 applies if groundwater is within any of the following areas: Current Drinking Water Source Areas; or Potential Drinking Water Source Areas Category GW-2 applies if groundwater is within: 30 feet of an occupied building or structure and the average annual depth to groundwater is 15 feet or less. Category GW-3 applies: Groundwater at all locations is considered category GW-3. The Site is located within a current or potential drinking water source area. Groundwater was detected at less than 15 feet below the ground surface such that categories GW-1, GW-2 and GW-3 apply to the Site. 7.2 Identification of Contaminants of Concern COCs are petroleum related compounds detected in a medium (i.e. soil or groundwater) at the Site at levels above background. Background concentrations for all COCs are assumed to be below laboratory reporting limits. Therefore the COCs for the Site consist of the EPH ranges C9 to C18 and C19 to C36 aliphatic compounds and C11 to C22 aromatic compounds. 7.3 Identification of Exposure Points and Exposure Point Concentrations Soil Exposure Points for soil are defined by the vertical and horizontal distribution of the material in soil in combination with the soil category (ies) determined to be applicable (310 CMR (3) (b)). Following soil excavation activities, confirmatory soil samples were obtained from the excavation for EPH analysis. The reported concentrations of each of the detected compounds were less than the applicable MCP Method 1 S-1 Risk Standard, CSE conservatively used the maximum concentration detected as the EPC for these COCs. Groundwater Groundwater was analysis indicated no detectable concentrations of petroleum products after the completion of response actions at the Site. Therefore groundwater has been restored to a condition of no significant risk. 7.4 Exposure Point Concentrations and Method 1 Standard Comparison Applicable MCP Method 1 Soil Standards promulgated for each COC are compared to the soil November 2014 Page 12

17 EPC in Table 2 and the Method 1 groundwater cleanup goals were compared to the groundwater detection limits. All soil EPCs and groundwater detection limits are below the applicable MCP Method 1 Standards for all identified COCs in soil and groundwater. Pursuant to the MCP, a condition of No Significant Risk exists without restrictions since EPCs are less than the applicable MCP Method 1 Risk Standards. 7.5 Activity and Use Limitations All soil EPCs for each exposure point are less than applicable MCP Method 1 Standards and UCLs as demonstrated by comparison in the attached Table 2. Therefore, the implementation of an Activity and Use Limitation (AUL) is not required to achieve or maintain a level of No Significant Risk pursuant to 310 CMR (2)(2)(a). 7.6 Characterization of Risk of Harm to Safety Risk of Harm to Safety was evaluated pursuant to 310 CMR The conditions at the Site have been reviewed to assess whether any conditions associated with the fuel oil release from the exist or may exist in the foreseeable future do or could pose a threat of physical harm or bodily injury to people. Based on all available data for the Site, there is no evidence that Site conditions do or will pose a significant risk of harm to safety. The excavation has been backfilled to grade, the basement floor slab has been restored and confirmatory sampling has determined that a condition of no significant risk has been achieved and all uncontrolled sources have been eliminated as specified in the MCP at (5). 7.7 Risk to the Environment As noted above, the release migrated to a wetland area and after the remedial program was completed and the wetland restored as required by the Easton Conservation Commission, an ecological risk assessment was completed. The risk assessment is presented in Appendix D and in summary concluded that there was no risk to the environment. 7.8 Risk Characterization Conclusion This Method 1/Method 3 Risk Characterization concludes that the Site poses No Significant Risk of harm to health, public welfare or the environment. As discussed previously, CSE believes that the sampling program documented in this report is sufficiently representative and the data are sufficiently usable to address and establish that the response actions were effective in abating the petroleum release and that no EPCs exceed the applicable MCP Method 1 Risk Standards. SECTION 8.0 PERMENANT SOLUTION STATEMENT 8.1 General CSE has prepared this Permanent Solution Statement on behalf of the Morgan in order to comply with the requirements of the Massachusetts Contingency Plan (MCP), 310 Code of November 2014 Page 13

18 Massachusetts Regulations (CMR) The Immediate Response Action at the Site has been completed and the Risk Characterization determined that a level of No Significant Risk exists at the Site and that a Permanent Solution without restrictions has been achieved. The data meets the requirements of a Permanent Solution Statement under 310 CMR (2). These requirements are as follows: A Permanent Solution has been achieved (no further action required); There are no conditions associated with this Permanent Solution Statement; No uncontrolled sources remain on the Site; The levels of petroleum hydrocarbons in the environment have not been reduced to background; and No Activity and Use Limitation was required to maintain a level of No Significant Risk. A copy of the IRA Completion Statement (BWSC-105) and Permanent Solution Statement Transmittal Form (BWSC-104) are being submitted electronically to DEP along with this report. Pursuant to 310 CMR (3)(f), the Chief Municipal Officer and the Board of Health of the of the Town of Easton have been notified that an Permanent Solution has been achieved at the site and how to obtain a copy of the report. In addition, a copy of the report has been submitted to the Easton Conservation Commission and the property owner at Eastman Street Limited Partnership. A copy of the notification letters are provided in Appendix E. 8.2 Feasibility of Restoration to Background The feasibility of remediation to background has been evaluated pursuant to 310 CMR As previously mentioned, CSE conservatively considered background concentrations of OHM for the site to be below the laboratory reporting limits. Petroleum concentrations were identified in confirmatory soil samples. Petroleum hydrocarbons are considered nonpersistent/degradable per Table 9-1 of WSC Policy # In accordance with the policy, DEP considers achievement of background infeasible for degradable/non-persistent contaminants, except for small quantities of impacted considered accessible. The soil containing residual petroleum hydrocarbons were located in or proximate to a wetland that presents greater harm to the resource through the removal of additional soil. Therefore, in accordance with DEP Policy #WSC , the ability to reach or approach background at the release Site is Categorically Infeasible. SECTION 9.0 LSP CERTIFICATION 9.1 LSP Certification The seal and signature of the Cosmo Gallinaro, the LSP who prepared this IRA Completion Report and Permanent Solution Statement is provided on the IRA and Permanent Solution Statement transmittal forms. November 2014 Page 14

19 9.2 PRP Certification CSE has been authorized to sign DEP forms on behalf of the PRP. Authorization to act as agent was previously submitted to edep using Form 126. SECTION 10.0 LIMITATIONS Chemical analyses were performed for parameters associated with the release of heating oil during remedial response as described herein. However, additional chemical constituents not searched for during these response actions may be present in soil and/or groundwater at the Site. Chemical conditions reported reflect conditions only at the locations tested at the time of testing and within the limitations of the methods used. Such conditions can vary from area to area and from time to time. No warranty is expressed or implied that chemical conditions other than those reported do not exist within the Site. This report includes information that was provided by other parties. CSE has attempted to corroborate information provided by others; however, the complete verification of such information is not possible. November 2014 Page 15