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SITE ASSESSMENT & PERMAN SOLUTION STMT - SALEM SUEDE SP ENGINEERING, INC. P.O. Box 848 • Salem, Massachusetts 01970 • Telephone: 978-745-4569 • Fax: 978-745-4881 September 21, 2018 Kimberley Driscoll, Mayor City Hall 93 Washington Street Salem, MA 01970 RE: Comprehensive Site Assessment and Permanent Solution Statement Former Salem Suede and Former Bonfanti Leather 72 Flint Street and 69-71 Mason Street Salem, Massachusetts RTN 3-30380 Dear Mayor Driscoll: On behalf of Riverview Place, LLC,the purpose of this letter is to notify you that a combined Phase II—Comprehensive Site Assessment and Permanent Solution Statement has been prepared for the release of metals, polycyclic aromatic hydrocarbons, dioxins/furans and petroleum at the former Salem Suede facility at 72 Flint Street and the former Bonfanti Leather facility at 69-71 Mason Street in Salem, Massachusetts (the "Site") in accordance with the Massachusetts Contingency Plan, 310 CMR 40.0000. The Permanent Solution Statement documents that a Permanent Solution has been achieved for the release and that a condition of No Significant Risk to human health and the environment exists. A summary of findings and statement of conclusions is attached. A copy of this report may be obtained from the DEP Searchable Sites Waste Site List/Site Files web site https://eeaonline.eea.state.ma.us/portal#!/search/wastesite under Release Tracking Number (RTN) 3-30380 or by contacting SP, Inc. at 508-745-4569. Sincerely, SP, INC. Bruce M. Poole David L. Bramley, PE, LSP President Attachment c. Thomas St. Pierre, Director Inspectional Services Elizabeth Gagakis, Acting Health Agent MassDEP, NERO Michael O'Brien David Zion SUMMARY OF FINDINGS Permanent Solution Statement 72 Flint Street and 69-71 Mason Street, Salem, MA RTN 3-30380 The Riverview Place Site includes the former Salem Suede property at 72 Flint Street,the former Bonfanti Leather property at 69-71 Mason Street, and an adjacent former residence at 67 Mason Street. The Salem Suede Site property has been vacant since 2009;the Bonfanti properties have been vacant since 2012. The properties are located on the east side of Flint Street, south of Mason Street, and north of the North River Canal in a primarily residential area of Salem, Massachusetts. The Site slopes southerly toward the North River and based on the topography, the groundwater flow direction is southerly toward the North River. The Site is served by municipal water and sewer. Oil formerly was stored in a 10,000-gallon underground storage tank in the southwest portion of the Salem Suede property and in the northeast portion of the Bonfanti property. Electricity and telephone service formerly were provided via overhead lines. Stormwater drains to the North River. The Site is not located within a current or potential drinking water source area as defined in the Massachusetts Contingency Plan (MCP). However, much of the Salem Suede property is located within a 200-foot Riverfront Area and a 100-foot Wetland Buffer Zone. Private, potable water wells are not known to exist within 500 feet of the Site. Therefore, groundwater at the Site is classified as GW-2 and GW-3. The portion of the North River adjacent to the Site is known as Proctor Brook Segment MA93-40 and it is classified as Class SA. The River at this location is not managed as an active shell fishing growing area in accordance with the requirements of National Shellfish Sanitation Program (MassDEP, 2012). Further,the North River is categorized as a Category 5 water body,which is impaired and requires a Total Maximum Daily Load (TMDL). Impairments identified in this segment of the river include debris/floatables/trash,fecal coliform,foam/flocs/scum/oil slicks, and taste and odor (MassDEP, 2013). Subsurface investigations were conducted by SP in 2005 and 2009 as due diligence and by Weston &Sampson in 2012 as part of a Brownfields assessment. Laboratory analyses of soil samples collected detected the presence of elevated concentrations of the metals arsenic, chromium, lead, nickel, several hydrocarbon fractions, PAHs, and dioxins. The PAHs and the dioxins were thought to have originated from the use of coal in the former boiler the ash from which was spread on the Site. Also,the fires in 1914 and in 2009 may have contributed to the presence of the PAHs and dioxins. No definitive source of the dioxins has been identified. However, MassDEP is of the opinion that the presence of dioxins is related to former process operations. As such, MassDEP has stated that dioxins at the Site are not due to coal ash, wood ash, or anthropogenic background because Site homologue patterns are not consistent with coal ash or wood ash. Site homologue patterns were consistent with anthropogenic background, but mean homologue 1 concentrations were as much as an order of magnitude greater than anthropogenic background. The site homologue patterns were consistent with homologues at another tannery site with soil affected by pentachlorophenol. However, use of pentachlorophenol has not been identified based on historic research. Between April 2013 and November 2017 approximately 4,311 tons of soil were excavated and transported off the Site to appropriate disposal facilities under the March 2013 and the July 2016 Release Abatement Measure (RAM) Plans and the July 2017 RAM Plan Modification. Groundwater samples for all or some of the monitoring wells were analyzed between 2012 and 2016 for VOCs, EPH, metals, and PCBs. None of the analytes were detected at concentrations that exceed the Method 1, GW-2, and GW-3 Reportable Concentrations, except that lead has been detected in groundwater samples from monitoring well MW-2, MW-3, and MW-9 at concentrations slightly greater than the GW-3 standard. The source of the lead is thought to be suspended silt particles caused by the excavation activities as the lead concentration in the post-remediation groundwater samples are less than the GW-3 standards. Concentrations of constituents of concern in groundwater samples from the most recent sampling events are less than the GW-2, and GW-3 standards. The concentrations of lead in the samples collected during the latest two analyses (November 2014 and May 2016)were less than the laboratory Reporting Limit. A Method 1 Human Health Risk Characterization and a Method 3 Environmental Risk Characterization were performed to assess the risk of harm to human health, public welfare, safety, and the environment using site-specific data, current and potential future uses of the site, and recommended MassDEP risk characterization guidance. The risk characterization results indicate the following: ➢ A condition of No Significant Risk of harm to human health and public welfare exists for current and future residents under unrestricted site uses. ➢ The Site poses No Significant Risk of harm to safety because no conditions related to the release that could pose a threat of physical harm or bodily injury was identified. The site poses No Significant Risk of harm to the environment. After redevelopment, undeveloped portions of the Disposal Site will occupy less than two acres and there are no areas of special concern within 500 feet of the site. Due to size, use, and location, the Site does not provide a balanced terrestrial community, so no further assessment and remediation for terrestrial environmental concerns are needed. Therefore,the risk characterization concludes that the release poses No Significant Risk of harm to the environment and a Stage II Environmental Risk Characterization is not needed. Aquatic environmental exposure pathways potentially are complete; however, COC concentrations in groundwater are less than the surface water-based criteria in groundwater or after discharging to and mixing with the North River. Therefore,the conclusion is that the North River will not be adversely affected by current site groundwater conditions. 2 Based on the information presented herein, no condition of readily apparent harm or any potentially significant exposures have been identified at the Disposal Site. Therefore, based on the criteria set forth in the MCP (310 CMR 40.0995), conditions present at the Disposal Site do not warrant a Stage II Environmental Risk Characterization and the Disposal Site conditions do not present a significant risk of harm to the environment. Based on the findings of the assessment activities, the remedial actions, and the Risk- Characterization presented herein, a level of No Significant Risk as defined in the MCP exists for all foreseeable uses. These findings and the additional information presented below support the applicability of a Permanent Solution for the Disposal Site. 3