Beginning in the early 1940s, Adak Naval Air Facility (NAF) served as a key operations and supply location for U.S. military forces. A study identified 32 sites at the installation, including landfills, unexploded ordnance areas, and polychlorinated biphenyl (PCB) spill sites, which have contaminated groundwater, surface water, sediments, and soil.
Environmental restoration projects began on Adak under the Navy Assessment and Control of Installation Pollutants program with an initial assessment study (IAS) in 1986. The IAS identified 32 sites on Adak that could be a potential threat to human health and the environment. In 1988, site inspections were conducted at areas identified in the IAS. In 1989, a RCRA facility assessment (RFA) was completed by EPA under the RCRA corrective action program. Adak was proposed for the U.S. Environmental Protection Agency’s (EPA) National Priorities List in October 1992 and it was officially placed on the NPL in May 1994.
As a result of the RFA, preliminary source evaluations (PSEs) were conducted between 1993 and 1996 for a majority of the CERCLA sites initially identified under the IAS. The PSE process was a risk-based screening approach endorsed by EPA and ADEC to determine which potentially hazardous source areas posed a human health and ecological risk. Fifty-eight sites identified by the PSE process as requiring additional evaluation were included in the basewide remedial investigation and feasibility study (RI/FS). The former base was divided into two operable units, OU A and OU B. OU A includes 58 CERCLA sites and 128 petroleum sites covered by SAERA. Sites within OU A are categorized as either petroleum sites, CERCLA sites, or landfill sites. Some sites are considered both petroleum and CERCLA sites due to the presence of both petroleum and CERCLA regulated substances in soil and/or groundwater. Petroleum sites on Adak are regulated under 18 AAC 75. CERCLA expressly excludes petroleum from its definition of hazardous substances (Section 101(14)), and therefore petroleum is not regulated under CERCLA. Instead, petroleum releases on Adak are regulated solely by the State of Alaska under 18 AAC 75. Issues regarding ordnance explosives are being addressed under OU B.
Twenty sites were recommended for further investigation. In addition, a RCRA facility assessment identified 76 solid waste management units (SWMUs), 73 of which are managed as CERCLA sites. DoD and EPA signed a federal facility agreement (FFA) in November 1993, outlining how they were going to proceed with cleanup. The potential risk to human health and the environment was significant enough for EPA to place the installation on the NPL in May 1994. In September 1995, the BRAC Commission recommended closure of Adak NAF. Operational Naval forces departed the island on April 1, 1997, and Engineering Field Activity Northwest assumed command functions. The installation closed in September 1997. The installation completed a community relations plan in FY90 and revised the plan in FY95, FY99, and FY03. In FY96, Adak NAF converted its technical review committee responsible for communicating cleanup progress with the community into a Restoration Advisory Board. To ensure continuous monitoring and improvement, the installation completed five-year review reports in FY01 and FY08.
The installation has signed Records of Decision (RODs), which selected cleanup actions for Operable Units (OUs) A and B1. Adak NAF also signed two No Further Action RODs, which determined that no further cleanup activities were necessary for SWMUs 4, 27, and several sites originally included in OU B. The installation also signed a Decision Document (DD), which selected cleanup actions for 10 of the 14 free-product petroleum sites at OU A. In FY04, Adak NAF transferred approximately 47,000 acres for private reuse. The installation completed environmental cleanup on an additional 24,300 acres, which were transferred to the Department of the Interior in FY04. In FY02, Adak NAF conducted an inventory of sites suspected to contain munitions contamination for the Military Munitions Response Program (MMRP); one MMRP site was identified. Cleanup progress at Adak NAF for FY05 through FY08 is summarized below.
In FY05, Adak NAF completed closure documentation for 19 petroleum release sites. The installation also completed post-closure care restoration work (vegetative cap maintenance) at two landfills. The installation completed feasibility studies (FSs) to evaluate cleanup alternatives at the four remaining sites. Adak NAF completed proposed plans (PPs) and began DDs for three of the remaining sites. The installation completed the focused FS, PP, and DD for the remaining petroleum sites.
In FY06, Adak NAF continued long-term management (LTM) at 29 CERCLA and petroleum release sites under the OU A ROD. The installation completed DDs and cleanup for three petroleum release sites and completed characterization at another site.
In FY07, Adak NAF continued LTM at 29 CERCLA and petroleum release sites under the OU A ROD. The installation also completed a conditional site closure at one petroleum release site, and continued free-product removal at three petroleum release sites. Under the MMRP, the installation resolved OU B1 ROD disputes.
In FY08, Adak NAF completed a second five-year review report. The installation also continued LTM at 29 CERCLA and petroleum release sites under the OU A ROD. Adak NAF continued free-product removal at three petroleum release sites and completed an FS for the remaining petroleum release site. Regarding MMRP sites, the installation completed fieldwork at Site LJ 01 and the Munitions and Explosives of Concern Rifle-Grenade Range, and completed fieldwork for the remedial investigation (RI) and FS at OU B2. The State of Alaska granted conditional closure for 17 OU B1 sites.