Yuma Marine Corps Air Station sits on about 3,000 acres in Yuma County, Arizona. EPA placed it on the Superfund National Priorities List in 1990 after chlorinated solvents turned up in groundwater. The Department of Defense runs cleanup here through its Installation Restoration Program. Physical construction of remedial actions was completed in 2000, but the site remains in an operation and maintenance phase with active monitoring and long-term work still underway.
Contaminants include 1,1-dichloroethene, tetrachloroethene, trichloroethene, and volatile organic compounds (VOCs) in groundwater. Soils contain arsenic, cadmium, copper, lead, zinc, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), pesticides, and metals. Unexploded ordnance (UXO) is also present in soil and solid waste in one operable unit. A separate operable unit addresses per- and polyfluoroalkyl substances (PFAS), a class of man-made chemicals linked to health concerns, with a remedial investigation that began in 2021 and is expected to finish between September and November 2027.
Cleanup is divided into several operable units. Groundwater treatment used air stripping, air sparging, soil vapor extraction, and a pump-and-treat system. Soil remediation is complete for most areas, with visible asbestos-containing materials removed and institutional controls placed at remaining subsites. The most recent five-year review, completed September 21, 2025, found that remedies are expected to be protective upon completion. A removal action at one operable unit is estimated to wrap up between August and October 2026.
Human exposure has not yet been fully controlled. An unsafe level of contamination has been detected, and people could reasonably be exposed to it. Groundwater migration status is uncertain due to insufficient data on whether contaminated groundwater movement has stabilized. Institutional controls restrict access to contaminated groundwater and soils while work continues. The site has not been deleted from the National Priorities List and has not achieved sitewide ready-for-anticipated-reuse status, though redevelopment may still be possible on portions of the property.
Community members with questions can contact the EPA Community Involvement Coordinator or Remedial Project Manager. Both can help direct the public to site documents and the Administrative Record, which the Marine Corps maintains as the lead federal agency.
