Known today as a premier urban national wildlife refuge, the Rocky Mountain Arsenal (RMA) is one of the most-studied environmental cleanup sites in the country.  The U.S. Army built the site in 1942, following the attacks on Pearl Harbor, as a chemical weapons manufacturing facility. As production declined at war’s end, the Army leased a portion of the idle facilities to Shell Chemical Co., for the production of agricultural chemicals. The Army later reactivated Arsenal facilities for Cold War production and demilitarization.

Although the U.S. Army and Shell used accepted disposal practices of the time, decades of chemical and agricultural production led to contamination of some of the soil, structures and groundwater. Following an extensive site investigation, the Army and Shell developed cleanup plans in collaboration with the community and with federal, state and local regulatory agencies.

The safe, comprehensive environmental cleanup of RMA’s soils and structures concluded successfully in 2010. As the cleanup progressed and projects met state and federal requirements, the Army transferred lands to the U.S. Fish and Wildlife Service to manage as a national wildlife refuge.

The U.S. Army continues to maintain approximately 1,100 acres at the site. In cooperation with the EPA, Colorado Department of Public Health and Environment and Adams County Health Department, the Army operates groundwater treatment facilities and two on-site landfills and two waste consolidation areas located on the Army’s property. The Army will continue to treat groundwater until water leaving the site meets state and federal standards.