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NPL Site Narrative for Andersen Air Force Base
ANDERSEN AIR FORCE BASE
Yigo, Guam
Federal Register Notice: October 14, 1992Conditions at Proposal (February 7, 1992): Andersen Air Force Base (AAFB) is located in Yigo on the northern end of the island of Guam. The main base and annexes of AAFB occupy approximately 20,000 acres. Navy and Air Force installations occupy most of the northern half of the island. Approximately 34,000 people live within 4 miles of the site in the Cities of Dededo, Tamuning, and Yigo. The population living, working, and attending school on AAFB currently includes 3,400 military personnel, 600 civilians, and 4,000 dependents. The land occupied by AAFB provides habitat for four species designated as endangered by the U.S. Fish and Wildlife Service.
AAFB has been operational since the 1940s. Its major mission is support for Strategic Air Command operations. Sources of hazardous substances at AAFB include unlined landfills, drum storage and disposal areas, chemical storage areas, fire training areas, waste storage areas, a laundry, and industrial and flight line operations. Substances known to be involved in AAFB's operations include: solvents such as trichloroethene (TCE) and paint thinners; dry cleaning fluids and laundry products; fuels such as JP-4 and gasoline; pesticides; antifreeze; aircraft cleaning compounds; and PCBs.
AAFB is located in a karst limestone terrain. Inadequately contained sources of hazardous substances are located in sinkholes that provide a direct route for contamination to reach ground water. The Northern Guam Lens, which underlies the site, has been designated a Sole Source Aquifer under the Safe Drinking Water Act. This designation is based upon two criteria: 1) the aquifer supplies drinking water to 50 percent or more of the area's population and 2) if contaminated, the aquifer would present a significant risk to public health.
Air Force analyses indicate the presence of lead, chromium, TCE, toluene, and tetrachloroethene in ground water beneath the site. However, not all of these materials can be attributed to AAFB operations, and background levels have not been determined for the metals, which occur naturally. An estimated 40,200 people obtain drinking water from wells within 4 miles of the site.
Status (October 1992): EPA, the Guam environmental agency, and the Air Force are negotiating a Federal Facilities Agreemnet under CERCLA Section 120 to cover future activities at the 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 http://www.atsdr.cdc.gov/toxfaq.html or by telephone at 1-888-42-ATSDR or 1-888-422-8737.