NPL Site Narrative for McChord Air Force Base (Wash Rack/Treatment Area)
MCCHORD AIR FORCE BASE (WASH RACK/TREATMENT AREA)
Federal Register Notice: July 22, 1987
Conditions at proposal (October 15, 1984): McChord Air Force Base covers about 6,000 acres just south of Tacoma in Pierce County, Washington. It is on an upland plain, 5 miles east-southeast of Puget Sound. Since 1940, almost 500,000 gallons of hazardous substances have been used and disposed of on the base. The Air Force has detected chloroform, benzene, arsenic, chromium, and mercury in test wells on the base, as well as in surface drainage (Clover Creek) leaving the base.
This NPL site consists of two areas: the liquid waste spill and disposal area adjacent to the wash rack and the industrial waste treatment system. The wash rack has been active since the 1940s. A wide variety of solvents, detergents, paints, and corrosion-removing compounds have been used there. Industrial wastes from other sources also were directed to the wash rack. The industrial waste treatment system includes an oil skimmer with two leach pits. At times, oils were discharged directly into the leach pits, which had to be re-excavated because they were plugged from sludges and oils.
McChord Air Force Base, the Lakewood Water District, and American Lake Gardens (a private development) get their drinking water from the aquifer partially underlying McChord. (Lakewood was added to the NPL in September 1983 and American Lake Gardens in September 1984.) Well over 10,000 people within 3 miles of the base depend on the aquifer for their drinking water.
The Air Force has investigated the contamination as part of 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 constructed numerous wells to verify the contamination. Several contaminated areas have been found, although specific sources are still being investigated.
Status (July 22, 1987): This specific area is not being investigated at this time due to a higher priority study associated with the known contamination problem at American Lake Gardens potentially involving the installation.
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.