Record of Decision (Rods)
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EPA/ROD/R10-95/111 1995 EPA Superfund Record of Decision: ADAK NAVAL AIR STATION EPA ID: AK4170024323 OU 01 ADAK, AK 03/31/1995 DECLARATION OF THE RECORD OF DECISION SITE NAME AND LOCATION Naval Air Facility Adak Site 11 (Palisades Landfill) and Site 13 (Metals Landfill) Adak Island, Alaska STATEMENT OF PURPOSE This decision document presents the selected interim remedial actions (IRAs) for Sites 11 and 13 (Palisades Landfill and Metals Landfill), which are part of Operable Unit A at the Naval Air Facility (NAF) Adak, Adak Island, Alaska. The remedies selected in this decision document were developed in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act, as amended by the Superfund Amendments and Reauthorization Act, and the National Oil and Hazardous Substances Pollution Contingency Plan. The documents supporting the decision are in NAF Adak's Administrative Record. The United States Navy (Navy) is the lead agency for this decision. The interim remedial action's proposed in this plan were reached as part of the Federal Facilities Agreement (FFA) for NAF Adak, which is a legal agreement between the Navy, the United States Environmental Protection Agency (EPA), and the Alaska Department of Environmental Conservation (ADEC). EPA approves of this decision, and along with ADEC, has participated in the evaluation of remedial action alternatives. The State of Alaska concurs with the selected remedy. These FFA parties entered into a joint agreement to evaluate and clean up hazardous substances on Adak Island. The agreement follows both state and federal regulations. This agreement went into effect on November 24, 1993. For the two landfills discussed in this Record of Decision (ROD), a complete assessment of potential human and ecological risk was not performed prior to a decision to take remedial action. The remedial investigation (RI) for NAF Adak, scheduled to begin in October 1996, will include a basewide comprehensive risk assessment that will include Palisades and Metals Landfill. Following that assessment, the FFA parties may propose additional remedial actions at the Landfills sites as part of a final basewide remedial action. ASSESSMENT OF THE SITE Releases of hazardous substances from Palisades and Metals Landfill if not addressed by implementing the response actions selected in this ROD, may potentially present an imminent and substantial endangerment to public health, welfare, and/or the environment. DESCRIPTION OF THE SELECTED AND CONTINGENT REMEDIES The selected IRAs at Palisades and Metals Landfills, at NAF Adak, Adak Island, Alaska, address the potential chemical exposures and associated risks to human health and the environment by minimizing the potential for exposures to site contaminants and off-site contaminant migration. The following lists provide the major components of the IRA for each landfill. Palisades Landfill)Selected Alternative • Reroute Palisades Creek to reduce surface water contact with landfill waste. • Construct small interceptor ditches along the uphill side of the landfill to collect water flowing off the hillside. The water will be routed around the perimeter of the landfill and into Palisades Creek. • Add landfill cover over approximately 6 acres. • Establish vegetation over the newly constructed landfill surface by seeding and take measures to prevent erosion. Erosion control measures may include jute matting, filter fabric fences, and hay/straw bales. • Implement institutional controls such as residential use restrictions and control and installation of signs around the perimeter of the landfill to warn the public of its contents, and conduct a boundary survey of the landfill. • Conduct a monitoring program that will involve sampling and analyzing water and sediments collected from the mouth of Palisades Creek, and inspecting the overall physical condition of the landfill and landfill cover to determine whether erosion or settlement has occurred that could be detrimental to the landfill cover or could lead to potential danger to human health and/or the environment. Metals Landfills)Selected Alternative • Conduct a site removal evaluation on the shoreline debris located in the northern section of the landfill. The shoreline debris will be inspected and material that could adversely affect the marine environment will be removed from the shoreline and properly disposed. Sediment samples will be taken and the results will be screened against risk-based screening concentrations (RBSCs). If exceedances of RBSC can be linked to the debris present, that debris will be removed from the shoreline and placed on the landfill. The debris will be evaluated for stability and, if necessary, measures will be taken to prevent further debris from contacting the marine environment. • Construct small interceptor ditches on the uphill side of the landfill at the base of Monument Hill to collect surface water flowing off the hill above the landfill. The ditches will divest the water into Kuluk Bay. • Add a landfill cover over approximately 17 acres. • Install five additional groundwater monitoring wells near the east and north perimeter of the landfill, toward Kuluk Bay to provide adequate coverage near the shoreline. • Establish vegetation over the newly constructed landfill cover and take measures to prevent erosion. • Implement institutional control such as residential use restrictions and controls and installation of signs around the perimeter of the landfill to warn the public of its contents, and conduct a boundary survey of the landfill. • Conduct a monitoring program that will involve sampling and analyzing groundwater, and inspecting the overall physical condition of the landfill and landfill cover to determine whether erosion or settlement has occurred that could be detrimental to the landfill cover or could lead to potential danger to human health and/or the environment. Metals Landfill)Contingent Alternative • Include all elements listed under Selected Alternative with the exception of the landfill cover. • Construct an engineered landfill cap over approximately 17 acres. STATUTORY DETERMINATIONS The selected and contingent IRAs for Palisades and Metals landfills comply with federal and state requirements that are legally applicable or relevant and appropriate to the remedial actions, and are cost-effective. These remedies utilize permanent solutions and alternative treatment technologies to the maximum extent practicable. However, because treatment of the "principal threat" at each site was not found to be practicable, the remedies do not satisfy the statutory preference for treatment as a principal element of a CERClA remedy. As shown in the evaluation of alternatives, the size of the sites, volumes of wastes and debris, and remote location preclude a practicable remedy that includes excavation and effective treatment. Since the selected interim remedies will result in possible hazardous substances remaining on site, a review must be conducted within 5 years after commencement of the remedial actions to ensure that the remedies continue to provide adequate protection of human health and the environment. Because the selected remedies are IRAs, a review of the remedies' protectiveness and a thorough evaluation of the statutory elements will be conducted as part of the basewide RI. Signature sheet for the Naval Air Facility Adak, Interim Remedial Action, Record of Decision, Sites 11 and 13, between the United States Navy, the United States Environmental Protection Agency, and the Alaska Department of Environmental Conservation. ________________________________ ___________________________________________ Date Captain L.W. Crane Commanding Officer, Navel Air Facility Adak United States Navy Signature sheet for the Naval Air Facility Adak, Interim Remedial Action, Record of Decision, Sites 11and 13, between the United States Navy, the United States Environmental Protection Agency, and the Alaska Department of Environmental Conservation. _____________________________________________ ________________________________ Chuck Clarke Date Regional Administrator, Region 10 United States Environmental Protection Agency Signature sheet for the Naval Air Facility Adak, Interim Remedial Action, Record of Decision, Sites 11 and 13, between the United States Navy, the United States Environmental Protection Agency, and the Alaska Department of Environmental Conservation. _____________________________________________________________________________ Marianne G. See Date Regional Administrator, Southcentral Region Alaska Department of Environmental Conservation CONTENTS Section Page DECLARATION OF THE RECORD OF DECISION ............................................. i ABBREVIATIONS AND ACRONYMS ..................................................... xvii UNITS OF MEASURE ................................................................ xix 1.0 INTRODUCTION ................................................................. 1 2.0 SITE NAMES, LOCATIONS, AND DESCRIPTIONS ...................................... 2 2.1 PALISADES LANDFILL (SITE 11) ........................................... 2 2.2 METALS LANDFILL (SITE 13) .............................................. 6 3.0 SITE HISTORY ................................................................. 9 3.1 PALISADES LANDFILL ..................................................... 9 3.2 METALS LANDFILL ........................................................ 9 4.0 COMMUNITY RELATIONS ........................................................