March Air Force Base sits in Riverside, California and has been on the National Priorities List since November 1989. The base has been an active military installation since 1918, and decades of aircraft maintenance, refueling, and repair left behind widespread contamination in soil, groundwater, and soil gas. Cleanup is well underway but not yet complete, with major construction work estimated to wrap up between December 2025 and February 2026.
EPA has identified more than 60 contaminants of concern at the site. These include volatile organic compounds (VOCs) such as benzene, trichloroethene, and vinyl chloride, as well as pesticides, heavy metals like lead and beryllium, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons. More recently, per- and polyfluoroalkyl substances (PFAS), specifically PFOA and PFOS, were found in soil and groundwater and are still being investigated. Some contaminants appear in multiple locations and media across the base.
The U.S. Air Force leads cleanup under a Federal Facilities Agreement signed in 1990 with EPA and state oversight. Cleanup is organized into six operable units covering different parts of the base. Major actions completed so far include consolidating old landfills into a modern facility, removing over 7,000 pounds of solvents through soil vapor extraction, pumping out 50,000 gallons of jet fuel equivalent, and treating 600 pounds of VOCs through groundwater extraction. A groundwater containment system called EGETS sits at the base boundary to stop further off-site migration of contaminated groundwater, and the off-site plume is being monitored. A soil vapor extraction system continues to run at one area of the base.
Drinking water wells on base were shut down in the late 1980s. Residents now get water from the Eastern Municipal Water District. Two residential wells and a municipal well were given alternate water supplies because of PFAS contamination. EPA assessments currently show human exposure is under control across the site, with no unacceptable exposure pathways at this time. Groundwater contamination is stabilized and contained. The most recent five-year review was completed in August 2024, and the next is expected between August and October 2028. The site has not yet been deleted from the National Priorities List and has not achieved sitewide ready-for-reuse status.
Community members with questions can contact the EPA's Community Involvement Coordinator or the Remedial Project Manager. The Air Force and the site's Public Information Repository also hold copies of the Administrative Record for public review.
