NPL Site Narrative for McClellan Air Force Base (Ground Water Contamination)
MCCLELLAN AIR FORCE BASE (GROUND WATER CONTAMINATION)
Federal Register Notice: July 22, 1987
Conditions at proposal (October 15, 1984): McClellan Air Force Base occupies about 2,600 acres approximately 8 miles northeast of Sacramento, Sacramento County, California. The base uses organic solvents for maintenance, repair, and modification of aircraft. In its initial investigations, the Air Force identified 46 past waste storage and disposal areas covering 56 acres within the base. Based upon disposal practices, geography, and potential threat, the 36 widely distributed areas on the base are currently considered as one site.
During the 1960s and early 1970s, the areas received wastes that included dewatered industrial sludge containing trichloroethylene (TCE), 1,1,1-trichloroethane, and 1,1-dichloroethylene. The Air Force has detected these solvents in monitoring wells and in public and private wells west of McClellan.
Since 1979, 12 off-base wells, including a municipal well, have closed due to TCE contamination. The municipal well was part of a blended system serving about 23,000 people. Where contaminants have exceeded or are expected to exceed the California Department of Health Services action levels, the Air Force is providing alternative water sources to residents.
A Ground Water Task Force consisting of representatives of the Air Force, local, State, and Federal agencies, and the public serves an advisory role and as a public forum.
McClellan Air Force Base is participating in the Installation Restoration Program, established in 1978. Under this program, the Department of Defense seeks to identify, investigate, and clean up contamination from hazardous materials. The Air Force has completed Phase I (records search) and Phase II (preliminary survey). Phase IV (remedy implementation) is being carried out at a number of on-site locations. The Air Force has initiated an off-site investigation.
Status (July 22, 1987): Phase II has investigated 68 on-base waste storage and disposal areas, including the original 46. The Air Force anticipates that further action is required at 27 areas. An additional 88 on-base areas have been identified as requiring Phase II investigations. Not all sources of contamination are believed to have been identified. The Air Force is planning a comprehensive remedial investigation/feasibility study.
As per a Task Force recommendation, the Air Force has capped one of the contaminated areas and built a system to pump and treat contaminated ground water. The Air Force is nearing completion of a project to hook up about 500 homes to a municipal water supply.
Within the boundaries of this Federal facility, there are areas subject to the Subtitle C corrective action authorities of the Resource Conservation and Recovery Act (RCRA). However, no such areas were included in scoring this specific site. Therefore, this Federal facility site is being placed on the Federal section of the NPL under the NPL/RCRA policy announced on September 8, 1983 (48 FR 40662).
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.