NPL Site Narrative for Alameda Naval Air Station
ALAMEDA NAVAL AIR STATION
Conditions at Proposal (May 10, 1999): Alameda Naval Air Station's mission was to maintain and operate facilities and provide support services for fleet aviation activities of the U.S. Navy. Historically, the site was occupied by a borax processing plant, an oil refinery, and an airport for the city of Alameda. In 1930, the site was purchased by the U.S. Army. In 1936, the U.S. Navy acquired the site and in 1940, the site was officially commissioned. Currently, the site covers approximately 1,600 acres of dry land and 1,000 acres of submerged land on the island of Alameda, California. The eastern portion of the site is devoted to office space, residential housing, and industrial facilities. Runways and support facilities occupy the western part of the site. The facility was closed by the Navy in 1997.
The U.S. Navy's Initial Assessment Study identified 12 potential hazardous waste sources at Alameda Naval Air Station (NAS), four of which were ultimately recommended for further investigation. However, the California Environmental Protection Agency, Department of Toxic Substances Control (formerly known as the California Department of Health Services, Toxic Substances Control Division), identified 16 additional sources at the site in a Remedial Action Order to the U.S. Navy. Subsequently five more sources were also identified. Consequently, remedial investigation/feasibility study (RI/FS) activities are being conducted at 25 areas on site, including the West Beach Landfill.
The West Beach Landfill occupies approximately 110 acres in the southwestern corner of the site. Approximately seventeen of these acres are now marshland. The West Beach Landfill is bordered to the west and south by the San Francisco Bay, and to the north and east by runways. Materials reportedly disposed of in the northeast portion ofthe West Beach Landfill include polychlorinated biphenyl (PCB)-contaminated transformer oils, PCB-contaminated TAC rags, and carbonless paper containing PCBs. The southwest portion of the landfill was used for the disposal of PCB-contaminated dredge spoils, which for the most part came from Alameda Naval Air Station's pier areas, turning basin, and entrance channel. Analytical results of samples collected from the southwest portion of the landfill indicated the presence of PCBs up to 483.9 micrograms per kilogram.
Approximately 17 acres of marsh cover most of the southwest portion of the West Beach Landfill. Results of a preliminary wetland delineation study identified wetland hydrology, hydric soils, and hydrophytic vegetation (as outlined in the 1987 Corps of Engineer Wetland Delineation Manual) in the West Beach Landfill marsh. The West Beach Landfill marsh is dominated by pickleweed, an obligate wetland species.
Property which has been identified as uncontaminated at Alameda NAS by the Navy pursuant to CERCLA Section 120(h)(4)(a), which has received regulatory agency concurrence pursuant to 120(h)(4)(b), is not part of the NPL site. Parcel Numbers 39, 60, 63, 93, 101, and 194 were identified and concurred on as uncontaminated, and therefore, are not part of the Alameda NAS NPL site. If additional uncontaminated property at Alameda NAS is identified in the future and receives appropriate regulatory agency concurrence, it will not be considered part of the NPL site. By definition, the NPL site consists of locations where releases of hazardous substances have occurred. If information becomes available indicating that parcels previously thought to be uncontaminated are in fact impacted by hazardous substances, these releases will be considered part of the NPL site.
The NAS Alameda NPL listing is not intended to include the subsurface soil contamination layer known as the former marsh crust and subtidal area. This 1 to 2 foot thick layer of soil contaminated with polynuclear aromatic hydrocarbons (PAHs) is buried an average depth of 8 to 15 feet below ground surface throughout most of the facility. Currently, a feasibility study has been drafted for the former marsh crust and subtidal area, and EPA anticipates that an institutional control will be implemented to address this issue towards the end of 1999. Before the Navy can transfer portions of the base property that are otherwise clean, it must satisfy CERCLA 120(h) requirements for closing military bases. Any other hazardous substance releases from the facility are included in this NPL listing.
Status (July 1999): EPA is considering various alternatives for this site.
For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet at ATSDR - ToxFAQs (http://www.atsdr.cdc.gov/toxfaqs/index.asp) or by telephone at 1-888-42-ATSDR or 1-888-422-8737.