F.E. Warren Air Force Base sits in Cheyenne, Wyoming and has been on the National Priorities List since 1990. The Air Force is responsible for cleaning up contamination left by past base operations, with the EPA and the Wyoming Department of Environmental Quality overseeing the work. The site is divided into 15 operable units covering landfills, spill sites, a firing range, base-wide groundwater, and a newer area focused on PFAS contamination.
Groundwater contains volatile organic compounds including trichloroethene, cis-1,2-dichloroethene, vinyl chloride, and 1,1,1-trichloroethane. Soil contains metals such as lead, arsenic, chromium, beryllium, nickel, and zinc, along with dioxins, DDT, and benzopyrene. These contaminants pose potential health risks through breathing, eating, drinking, or skin contact. Some contaminants appear in more than one location and more than one media type.
The Air Force has used several cleanup methods across the site. These include microorganism treatment to break down contamination in place, chemical treatment of groundwater, engineered landfill caps, landfill gas venting, a permeable reactive barrier wall, excavation, and physical separation of contaminated materials. Between 1984 and 1989, the Air Force removed contaminated soil, a grease tank, and a leaking storage tank. In 1996, it extended a water line to residents of the nearby Nob Hill neighborhood. In 1999, it installed the permeable reactive barrier and removed waste from one of the landfills. Several operable units have reached no-further-action status, and cleanup is complete at many other areas where monitoring continues.
The most recent five-year review, completed February 6, 2025, found that response actions match the remedy EPA selected and continue to protect human health and the environment. Overall site construction is not yet complete, and the site remains on the National Priorities List. The PFAS operable unit is the newest area of focus, with investigation running through late 2026 and a combined remedial investigation and feasibility study expected to finish between July and September 2028.
Community members can review site records at the Laramie County Library Reference Section on the third floor at 2200 Pioneer Avenue in Cheyenne. The EPA Remedial Project Manager, Shaun Cwick, can be reached by phone or email. The Wyoming Department of Environmental Quality contact is John Passehl, and the base's own Remedial Project Manager is Ernesto Perez.
