Wright-Patterson Air Force Base covers about 8,100 acres in southwestern Ohio near Dayton and has been on the National Priorities List since October 1989. The Air Force has been investigating contamination from past operations and waste disposal since 1981. The site was split into 12 cleanup projects and later organized into 17 operable units to manage different locations and problems.
The main contaminants are chlorinated volatile organic compounds, including trichloroethene and vinyl chloride, and benzene compounds. Dioxins, furans, polychlorinated biphenyls, metals such as arsenic, lead, and cadmium, and other chemicals like naphthalene and ammonia are also present. These contaminants show up in groundwater, soil, leachate, and landfill gas at locations that include two landfills, boundary areas, and earthfill zones across the base.
The Air Force leads cleanup with support from the U.S. EPA and Ohio EPA. A 1988 Consent Order with Ohio EPA and a 1991 Federal Facilities Agreement with U.S. EPA set the cleanup framework. Actions completed by 1999 included capping landfills, collecting and treating leachate and gases, extending public water lines to replace contaminated wells, removing drums and tanks, recovering fuel spills, and treating groundwater. Some areas required no action at all.
Despite construction being complete across the site, human exposure is not yet under control. Groundwater contamination is still moving rather than staying confined. Work continues on several operable units: a sitewide investigation of operable unit 14 has removal estimated for late 2026 and completion estimated for late 2027 or early 2028, operable unit 16 has a combined study expected to finish mid-2026, and operable unit 17 has investigation running through mid-2027. The most recent five-year review, completed October 8, 2025, found that current actions protect human health in the short term but that land use restrictions must stay in place for long-term protection. Zoning controls prevent residential development and other incompatible uses.
Community members with questions can contact the EPA's Community Involvement Coordinator, or the Remedial Project Manager for technical questions. Ohio EPA and Air Force representatives are also available.
