SALT LAKE CITY – Crews started demolition Thursday of an Army depot in Utah that was responsible for destroying more than 40 percent of the nation's stockpile of chemical weapons.
The Deseret Chemical Depot once held 13,600 tons of chemical agents, making it the world's largest stockpile of a witch's brew of toxins and blister and blood agents that accumulated throughout the Cold War.
Army officials said they've completed the destruction of chemical weapons at the site, no longer need its incinerator, and want to tear it down for safety reasons.
The demolition work at the site 45 miles southwest of Salt Lake City will last nine months and include dismantling the incinerator that destroyed liquid agents and munitions in 1,500-degree heat.
The depot didn't just hold obsolete U.S. weapons. A supply of nerve agent seized from Nazi Germany at the end of World War II was destroyed last year.
The U.S. Army has destroyed about 90 percent its chemical weapons under an international treaty. However, the job has taken 20 years longer and cost billions of dollars more than anticipated.
The U.S. still has a stockpile of mustard agent in Pueblo, Colo., and a mixed inventory of mustard and nerve agents at Blue Grass Army Depot in Kentucky.
Russia is further behind than the U.S., having destroyed only about 65 percent of its chemical-weapons cache, according to the Organisation for the Prohibition of Chemical Weapons in The Hague, Netherlands.
Deadlines set by the original treaty have been repeatedly pushed back because of the complexity of the work.
The U.S. is now helping Syria get rid of its chemical weapons.
The U.S. Army campaign involving its weapons started on a Pacific atoll in 1986 and was supposed to have destroyed all the nation's chemical weapons by an initial deadline of 1994. Now, the U.S. has until 2023 to complete the job.
The U.S. has never been known to use a chemical weapon in anger, although some consider the use of the defoliant Agent Orange during the Vietnam War a chemical attack, said Craig Williams, director of the Chemical Weapons Working Group in Berea, Ky., an advocate for safe disposal.
The demolition in Utah marks a milestone, he said.
"Clearly, it puts an exclamation point on the completion of the job there," Williams said. "There's no questioning our resolve to meet our commitments under the treaty."