October 1998 Proposed Plan to Clean Up Soils at the Fuel Spill No. 9 Site The Proposed Cleanup
The estimated present worth cost of cleanup is $501,175 over an 8-year period. This remedy will minimize risk to human health and to ecological receptors (plants and animals) by limiting exposure to contaminants. This Proposed Plan is issued by AFCEE, the lead agency for the Installation Restoration Program (IRP) at MMR, with support from the U.S. Environmental Protection Agency (USEPA), and the Massachusetts Department of Environmental Protection (MADEP). Words that appear in italics are defined in the Glossary at the end of this Proposed Plan. Learn More About AFCEE’s Proposed Plan A public meeting will be held on For additional information on the meeting, call Doug Karson, AFCEE Public Affairs Specialist at (508) 968-4678 ext. 2. What Do You Think? A public hearing will be held on There are two direct ways to provide a formal comment:
Comments may also be submitted by fax at (508) 968-4673 or by electronic mail message addressed to: doug.karson@mmr.brooks.af.mil or on the MMR Web site at http://www.mmr.org Introduction Some source control actions have already been conducted at FS-9. Three underground storage tanks (USTs) and related fuel-dispensing equipment were removed as part of the MMR Fuel Systems Upgrade Program in August 1994. Under the Drainage Structure Removal Program (DSRP), a catch basin and leaching well were removed and another leaching well was abandoned in place after decontamination of the structures and removal of all wastes. The DSRP is a systematic basewide investigation and cleanup effort to address drainage sumps that were used historically at MMR, including those at FS-9. Removal activities conducted under the DSRP are described more completely in the Drainage Structure Removal Program Remedial Action Workplan (Jacobs Engineering Group 1995). The DSRP activities will be summarized in the Drainage Structure Removal Program Remedial Action Summary Report (ABB-ES 1998), which is under review by USEPA and MADEP. USEPA placed MMR on the National Priorities List in 1989 for investigation under CERCLA. A Federal Facility Agreement, signed in 1991 and updated in 1997, required AFCEE to take the lead in cleanup activities at MMR, including the FS-9 site (Figure 1).
AFCEE’s activities to date at FS-9, carried out under the Installation Restoration Program, include performing a Site Investigation (SI) and Remedial Investigation (RI) to characterize the nature and distribution of contamination. Risk assessments were performed as part of the RI to identify potential risks from exposure to contaminants. The risk assessment evaluated the present and future risks to human health and the environment posed by existing conditions, assuming no remedial action is taken. Cancer and noncancer risks were evaluated. Additional activities include preparing a Feasibility Study to develop and evaluate remedial action alternatives to reduce site risks, and preparing this Proposed Plan. This Proposed Plan summarizes the Remedial Investigation/Feasibility Study and presents cleanup actions proposed for soils at three specific areas within FS-9. The three areas and other important site features are shown in Figure 2. The Proposed Plan, which is based on the Feasibility Study, describes various cleanup alternatives and the AFCEE preferred alternative. After careful consideration of several alternatives, AFCEE believes the proposed actions comprising the AFCEE preferred remedial alternative will protect human health and the environment and will comply with environmental laws and regulations.
Four General Categories of Cleanup Options Site Description and History Fuels, oils, greases, waste battery electrolyte, antifreeze, cleaners, and solvents from various vehicle maintenance operations were routinely used at FS-9. Most probable locations for the spilling or discarding of those materials were in the drainage structures and along the edge of the pavement, which was termed the former waste disposal area. While these materials may have been discharged to the ground surface, the lack of significant groundwater contamination at FS-9 may indicate that any remaining contaminants are largely bound to soils above the water table. History of Environmental Investigations at FS-9 1985 and 1992 Investigations 1993 to 1998 Remedial Investigation Activities Why Is Cleanup Needed at FS-9? The human health risk assessment for FS-9 evaluated potential exposure to site contaminants under hypothetical scenarios for utility workers, children and adults who might trespass on the site, and residential children and adults. The results indicated that unacceptable risks exist under the following scenarios: (1) for a child resident as a result of potential exposure to relatively high concentrations of lead in surface soils at the former UST location (793 mg/kg) and in the area of the SS-1 sampling location (767 mg/kg) and, (2) for unprotected utility workers who could be exposed to relatively high concentrations of C5-C8 aliphatic hydrocarbons (880 mg/kg) from subsurface soils at the test pit 11 location and from subsurface soils at the former UST location. The cancer and noncancer risks under all other scenarios from all other contaminants were found to be within USEPA and MADEP acceptable limits. The ecological risk assessment addressed hypothetical risks to terrestrial vertebrates and plants and to semiaquatic and aquatic receptors that may inhabit the undeveloped portion of the site west of the paved area of FS-9. Risks were evaluated for potential exposures to contaminated surface soil, surface water, and sediment. The only unacceptable ecological risk was found in relation to the concentrations of lead, chromium, vanadium, and zinc, which could potentially harm the short-tailed shrew. Potential ecological risks to aquatic receptors in the vernal pool were indicated due to the concentrations of metals detected in surface water and sediment samples. However, toxicity tests of sediment from the drainage ditch and pond/wet area indicated no acute or chronic effects on survival or reproduction in sensitive aquatic receptors, and no significant effects on reproduction in sensitive aquatic test receptors.
Cleanup Goals Cleanup Options at FS-9
Because potential ecological risks are concerns at this site, the Limited Action alternative was not evaluated in detail; the institutional controls of the Limited Action alternative have little ability to control ecological exposure and risk. Furthermore, the presence of institutional controls was not assumed in the risk assessment. Alternative 1: No Action. Alternative 1 does not include monitoring or any remedial action components to minimize potential risks to receptors or minimize the potential impact of leachable COCs on groundwater quality at FS-9. The No Action alternative was retained for detailed analysis to provide a baseline for comparison with other alternatives consistent with the requirements of CERCLA as required by USEPA. Alternative 2: Limited Action. Alternative 2 provides no treatment of contaminated media but includes institutional controls such as access and deed restrictions, warning signs, and groundwater monitoring. Alternative 2 also includes 5-year site reviews of site conditions and monitoring data from remedial actions to assess whether cleanup goals have been met, to determine if the remedy remains protective of human health and the environment, and to determine whether additional remedial action is justified. Alternative 3: Excavation and On-site Asphalt Batching. Alternative 3 consists of excavation and on-site cold mix asphalt batching of contaminated surface and subsurface soils at the three source areas. This treatment alternative involves excavating contaminated soils and mixing them with an asphalt emulsion. The asphalt emulsion coats the soil particles and immobilizes contaminants, thereby reducing exposure risk. In addition, the cold mix process minimizes the volatilization of VOCs. The stable asphalt-emulsion-coated product can be used as a subbase for paving projects. Asphalt-batching has been successfully used as a treatment alternative at other MMR sites to treat contaminated soil. Excavated soil would be tested before being mixed with the asphalt to confirm that the soil would meet regulatory requirements. If the soil exceeded acceptable levels, it would be disposed of at a permitted off-base facility. In addition to the excavation and treatment; this alternative includes institutional controls. Alternative 4: Excavation and On-site Asphalt Batching With Contingency Low Flow Soil Vapor Extraction. The excavation and asphalt batching component of Alternative 4 is the same as for Alternative 3, but Alternative 4 includes the use of low flow soil vapor extraction (SVE) if the depth of contamination exceeds the practical limits of excavation in the former UST location (see Figure 2). If contamination is beyond excavation limits, a soil boring would be drilled with soil sampling and analysis to determine the vertical extent of contamination. A pilot study would then be conducted to determine the proper design parameters for the SVE system. The SVE system would then be installed and operated until applicable cleanup goals are satisfied. SVE involves the injection of air through wells installed within the contaminated soil zone to remove hydrocarbon compounds. These compounds are recovered in adjacent vapor extraction wells and routed to an off-gas treatment system set up at the site to remove and treat the soil contaminants from the air stream. Soil sampling and monitoring well sampling would be used to demonstrate the effectiveness of the cleanup. In addition to excavation and treatment, this alternative includes institutional controls. Alternative 5: Excavation and Off-site Treatment/Disposal. Alternative 5 consists of excavating contaminated surface and subsurface soils at the three source areas and transporting them to an off-site treatment, storage, and/or disposal (TSD) facility permitted by USEPA to accept such waste materials. This alternative also includes institutional controls. Alternative 6: Excavation and Off-site Treatment/Disposal with Contingency Low Flow Soil Vapor Extraction. Alternative 6 includes the same excavation and off-site disposal of Alternative 5 but also includes a contingency for installation and operation of a low flow SVE system. The SVE system would be implemented, as necessary, to address any deeper soils contamination at the former UST location that could not be excavated as described for Alternative 3. This alternative also includes institutional controls. AFCEE's Preferred Alternative for FS-9 Excavation and On-Site Asphalt-Batching. During the design for this alternative a treatability study may be performed to determine key engineering parameters to ensure the effectiveness of the batching process. A total of approximately 994 cubic yards of soil would be removed at the three areas at FS-9. Soil would be sampled during excavation to guide the excavation operation. Results would be used to demonstrate that the excavation of contaminated soils is complete and for determination of treatment applicability and handling of excavated soils. Excavated soils would be processed in a cold mix asphalt batch plant set up on-site. Soils would be processed in a mixing chamber to mix the asphalt emulsion and stabilizing additives, resulting in a nonleachable, cohesive, stabilized product that can be used as a subgrade or base material for roads and parking areas. Batched asphalt would be used at MMR and possibly coordinated with similar cleanup efforts at other MMR sites. Contingency In Situ Soil Vapor Extraction. If the vertical limit of contamination is not reached during excavation of the former UST location, then sampling and analysis would be conducted to determine the vertical extent of contamination below the excavation. A pilot study would then be conducted to determine important design parameters for the SVE system to optimize cleanup of the deeper soil contamination. A detailed design would be prepared for the actual SVE system before implementation, but the system would generally involve the installation of air injection wells, one or more vapor extraction wells, and a vapor collection system. A mobile SVE system consisting of an air blower(s) for air circulation and an off-gas treatment system will be set up to remove and treat organic compounds. Periodic air monitoring will occur to ensure the effectiveness of the off-gas treatment system in eliminating contaminants from the treated air stream. Confirmational sampling of deep soils would be performed to ensure cleanup goals are met. Access and deed/zoning restrictions would be maintained at FS-9 during the cleanup period. A short-term monitoring program would be performed for a 5-year period to monitor the effectiveness of the excavation/treatment activity. This period would be extended as necessary to meet cleanup goals. Implementation of the asphalt batching process and the contingency low flow SVE at FS-9 would take approximately 24 months to complete. Operation of the SVE system could continue for 1 to 3 years after implementation. The total time frame for cleanup is not anticipated to exceed approximately 8 years at an estimated present worth cost of $501,175. AFCEE believes that this preferred remedial alternative would satisfy the requirements of CERCLA Section 121 (b), that the selected alternative is protective of human health and the environment, complies with ARARs, is cost effective, uses permanent solutions to the maximum extent practicable, and satisfies the statutory preference for treatment. Comparison of Alternatives The following table summarizes the comparison of alternatives evaluated in the Feasibility Study. The table on page 10 defines the evaluation criteria. A separate detailed analysis and comparison for each alternative was performed during the Feasibility Study; however, for simplification, the following tables compare each alternative against the criteria in general terms.
During the formal public comment period, AFCEE will accept formal written comments on the Proposed Plan and will hold a public hearing to accept either verbal or written comments. It is important to note that regulations distinguish between "formal" comments received during the public comment period and "informal" comments received outside of the comment period. AFCEE will respond to all comments post-marked by November 20, 1998 and AFCEE's responses will be documented in the Responsiveness Survey. You can submit a formal comment in any of the following ways:
Why Submit Formal Comments? A transcript of all formal comments and AFCEE’s written responses will be issued in a document called a Responsiveness Summary that will accompany the Record of Decision for FS-9. AFCEE expects to complete review of all comments, select a remedial alternative for FS-9, and issue the Record of Decision documenting AFCEE’s choice in January 1999. At that time, copies of the Responsiveness Summary will be mailed to everyone who submitted a formal comment and copies will also be placed in local libraries. In addition, AFCEE will announce the decision through the local news media and site mailing list. How Does AFCEE Choose a Final Cleanup Plan?
Of these nine criteria, protection of human health and the environment and compliance with ARARs are considered threshold requirements that must be met for a selected cleanup alternative to be selected. The next five criteria, called balancing criteria, are used to evaluate and compare the elements of alternatives that meet the threshold criteria. This comparison assesses which alternative provides the best balance of trade-offs with respect to long-term effectiveness and permanence; reduction of toxicity, mobility, or volume through treatment; short-term effectiveness; implementability; and cost. State and community concerns are considered modifying criteria factored into a final balancing of all criteria to select a remedy. Consideration of state and community comments may prompt AFCEE to modify aspects of the preferred alternative or decide that another alternative provides a more appropriate balance. For Further Information
Hours: 8:00 a.m. to 4:30 p.m., Monday through Friday Information and technical documents are also available at the main libraries in the towns of Bourne, Falmouth, Mashpee, and Sandwich; at the U.S. Coast Guard library at MMR; and at the MMR Web site (http://www.mmr.org). For further information, please contact: Doug Karson Jim Murphy Ellie Grillo Visit the Massachusetts Military Reservation on the World Wide Web: http://www.mmr.org
Applicable or Relevant and Appropriate Requirements (ARARs): Federal and/or state environmental laws and regulations that must be met during the implementation and completion of remedial actions. C5 through C8 Aliphatic Hydrocarbons: The cumulative concentration of all aliphatic hydrocarbon compounds with boiling points greater than 36ºC and less than 150ºC, as measured by chromatographic methods approved by MADEP or equivalent procedures, excluding the individual compounds listed at 310 CMR 40.0974(2)(MCP). Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA): This law, commonly known as Superfund, authorizes the federal government to respond directly to releases of hazardous substances that may endanger public health or the environment. Cleanup: Actions taken to remove contaminants from the environment. Drainage Structure Removal Program (DSRP): A comprehensive program to identify, characterize, and remove underground drainage structures, sumps, and associated soils at various sites across MMR. Feasibility Study: A study for identifying and evaluating options for remedial action to reduce risk to human health and the environment. Federal Facility Agreement: An agreement between USEPA and individual federal facilities that establishes a procedural and legal framework for investigating and performing remedial actions at Superfund sites. Inorganics: Metals and all compounds except hydrocarbons. Installation Restoration Program: The Department of Defense program implemented at military bases to identify, investigate, and clean up contamination resulting from past operations. Institutional Controls: Legal restrictions such as deed restrictions, zoning, fencing, or land use restrictions that prevent specified activities from occurring in specified areas to reduce or eliminate exposure. Massachusetts Contingency Plan: A general reference to Massachusetts regulations contained in 310 CMR 40.0000. National Priorities List: USEPA’s list of uncontrolled or abandoned hazardous waste sites that are priorities for long-term remedial evaluation and response. NPL sites are eligible to receive federal funds for investigation and cleanup under the Superfund program. Present Worth: the amount of money that, if invested now and disbursed as needed, would be sufficient to cover all costs associated with the remedial action over its planned life. Proposed Plan: A document that summarizes for the public the preferred remedial action for a site and presents the rationale for the preference. Remedial Action: Action taken to reduce or eliminate the long-term risks to human health or the environment from exposure to contaminants. Remedial Investigation (RI): An investigation to gather and analyze the data necessary to determine the nature and distribution of contamination at a site and to provide information for performing a feasibility study. Risk Assessment: An evaluation of human health and ecological risk resulting from exposure to a chemical or pollutant. Soil Target Cleanup Level: (STCL): MMR-specific risk-based and leaching-based concentrations of contaminants in soils developed for the protection of human health and the environment under the MMR Drainage Structure Removal Program.
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