History

The State of Missouri was host to 165 Minuteman II missile sites managed by the U.S. Air Force (USAF) from 1964 until 1997. The Minuteman II missile sites were built from 1961 to 1972, were fully operational and placed on high alert. The sites were scattered across 14 counties on land previously used for agricultural purposes. Of the 165 sites, 150 were launch facilities or silos that each contained a Minuteman II missile and 15 sites were launch control facilities. The 165 Minuteman II missile sites in Missouri were decommissioned in the 1990's as a result of the international Strategic Arms Reduction Treaty.

 Minute Man Missle Sites

Click map to enlarge.

The deactivation process at the 150 launch facilities involved removing the missiles, imploding missile silos and covering them with soil and an impermeable barrier limiting groundwater infiltration into the imploded silos. Fourteen of the 15 launch control facilities were not imploded or buried, but were sealed by decommissioning the elevator, filling the elevator shaft with inert fill material and placing a concrete cap over the elevator shaft. The remaining launch control facility is located within Whiteman Air Force Base and is currently functioning as a Minuteman II museum, offering scheduled tours to the public. 

Investigation

During the deactivation process, investigators discovered that waterproofing materials used in the construction of the missile silos and underground storage tanks contained polychlorinated biphenyls, also known as PCBs. Investigation also revealed that some of the sites had leaking petroleum underground storage tanks. Five years of groundwater sampling data confirmed the PCBs were not migrating into the groundwater and petroleum contamination was decreasing through a process called natural attenuation, in which microorganisms in the soil break down the chemicals into non-toxic substances. 

It was neither technically nor economically practical to remove the PCB contamination because the silos were buried at a depth of 80 feet. Therefore, the USAF, the Missouri Department of Natural Resources and the U.S. Environmental Protection Agency (EPA) agreed to leave contaminants in place as they were prevented from human exposure through encapsulation. The agencies involved also agreed to prohibit disturbance of capped contamination through land use controls memorialized through restrictions placed on deeds transferring each property from the federal government to private owners. At the completion of the closure process, each Minuteman II property was sold by the U.S. General Services Administration to adjacent landowners or other interested parties. The department, EPA and the U.S. Air Force continue to work together under a formal agreement to ensure the continuing safety of the closed Minuteman II sites.

Land use restrictions and educating Minuteman II property owners are critically important to our continuing stewardship of the former missile sites in Missouri. Adherence to land use restrictions ensures the effectiveness of engineering controls, which in turn, protects human health and the environment. Considerations for land-use improvements can be submitted through the property change request form below.

Information for Minuteman II Property Owners