By Tammy Walquist
Deseret Morning News

TOOELE — County commissioners and workers at the Deseret Chemical Depot's weapons incinerator celebrated a milestone Friday — the complete destruction of deadly agents VX and GB.

The depot has the largest chemical weapons stockpile in the United States. About 50 percent of the GB agent in the U.S. has now been destroyed because of the work here, said Alaine Southworth, public affairs specialist for depot.

The destruction of the agents also lessens the hazard they present to area residents.

"The destruction of the agents is wonderful. It reduces the risk to our county by 99 percent," said Tooele County Commissioner Colleen Johnson. "I'm impressed with what they do and how they do it."

Tooele Chemical Agent Disposal Facility officials say the safety of the community is of the highest importance to them.

"The community has been very, very supportive of the work we're doing," said DCD Commander Col. Ray Van Pelt. "If we ever have a problem or safety concern, we call the counties in 10 minutes to let them know what's going on. It's been a positive experience to work with the community as we do."

Nerve agents VX and GB have been stored in Tooele since 1942. Such weapons were stockpiled in the United States during the 1940s, '50s and '60s as a response to other nations known to be doing the same. The destruction of the nerve agents began in August 1996, under an international chemical weapons treaty.

The agents are destroyed by incineration. They are first brought to the facility in special containers designed to prevent leakage. Explosive components and liquid agents are extracted and properly destroyed at extremely high temperatures. Empty munition casings are decontaminated, also at high temperatures, and the metal is then recycled or taken to a hazardous waste disposal facility.

Although the destruction of VX and GB nerve agents represents a milestone for DCD, the facility still has a big task ahead of it.

Work has begun decontaminating the plant to prepare for processing the last of DCD's agent stockpile — nearly 125,000 mustard gas-filled munitions, a process Van Pelt estimates will take until 2012.