The military discovered soil and groundwater contamination at F.E. Warren Air Force Base, located west of Cheyenne, in the 1980’s. Contaminated soil and groundwater has been removed or treated and clean-up is ongoing to address remaining contamination.

The Wyoming Air National Guard has been cleaning up contaminated properties, such as the site located at the Cheyenne Municipal Airport, since 2001.  Long-term plans are in place for ongoing clean-up where soil or groundwater contamination still exists.

When the military inactivates, or decommissions, a site, they become known as Formerly Used Defense Sites (FUDs).  The Federal Facilities Program and federal partners work with current land owners to find acceptable clean-up methods for these sites. There are currently several dozen FUDs located in Wyoming.  Top priority sites for clean-up include those which impact drinking water supplies. 

The extent and nature of the soil and groundwater contamination is often unknown.  Groundwater contamination plumes can extend hundreds of feet, or more, so investigations are currently in progress to better characterize contamination at federal facilities in Wyoming.

Investigations at one FUD determined that the plume from the Belvoir Ranch site extends for more than 10 miles.  Municipal and private wells were impacted by this plume, so this FUD was particularly important to clean up.  Due to the successful collaboration between the land owners, the Federal Facilities Program and federal partners, the water produced by these wells is being treated and no longer poses a danger to human health. Photos, maps, site investigation reports and more can be found at the Atlas Missile Site 4 Information website.