During the 1960s, the U.S. Army Umatilla Chemical Depot in Eastern
Oregon began receiving and storing chemical munitions as one of eight chemical stockpile sites in the continental United States. The stockpile
eventually reached a total of 3,717 tons of chemical agents in
approximately 220,000 individual munitions. The chemical weapons stored
at the Depot represent approximately 12 percent of the United
States' original chemical weapons stockpile.
In 1985, Congress directed the Army to destroy the entire U.S.
chemical agent stockpile per the Chemical Weapons Convention treaty,
which requires signatory countries to destroy all chemical agent
stockpiles by 2007, a deadline later extended to 2012.
Destroying chemical weapons safely to avoid harm to the environment
and human health requires careful and rigorous processes, safety
measures, controls and oversight.
In February 1997, the Environmental Quality Commission, Oregon DEQ's
governing board, issued environmental permits to the U.S. Army to
construct, operate and ultimately close down the Umatilla facility after
destroying the stockpile. Construction of the Umatilla Chemical Agent
Disposal Facility was completed in August 2001 and the Depot began
destroying chemical weapons in 2004.
DEQ staff oversee the day-to-day operation of the
Agent Disposal Facility, ensuring that the Army and its contractor
comply with the hazardous waste and air permits. Throughout the process,
DEQ has involved the communities of Umatilla and Morrow counties and the
Confederated Tribes of the Umatilla Indian Reservation with regular
Successful destruction of the chemicals is eliminating a significant
risk to the environment and human life. The Umatilla plant is destroying
the weapons via incineration with a myriad of protective measures
accompanied by one of the nation's most advanced emergency response
The last bomb in the Umatilla stockpile was destroyed in 2006 and the
last munitions containing nerve gas were destroyed in 2008. The Army
expects to complete its final phase, disposal of mustard agent, by 2011,
on schedule for closure of the facility in 2012.