SALT LAKE CITY—A U.S. Army facility in Utah that once stored more chemical weapons than any other site in the country on Monday began destroying what’s left of its stockpile by incinerating the last container of liquid mustard agent.
The Army’s Deseret Chemical Depot at one time stored 43 percent of the country’s chemical weapons.
Since 2006, it has destroyed 12.3 million pounds of mustard agent, a chemical weapon first used by Germany during World War I to disable opposing armies by causing severe, painful but nonfatal blistering.
The gas also can cause cancer, and even low levels of exposure can threaten workers and the public. The Army said all of its disposal techniques are safe.
Lesser amounts of mustard gas remain at Army facilities in Alabama, Colorado, Kentucky and Oregon, where incineration of 1,000, one-ton containers of mustard agent at the Umatilla Chemical Depot is under way.
Projectiles and mortar cartridges containing mustard agent in liquid form at the Utah site about 50 miles southwest of Salt Lake City are scheduled to be destroyed by the end of the year, said Army spokeswoman Alaine Grieser.
Greg Mahall, a spokesman for the U.S. Army Chemical Materials Agency, said four other storage depots—Johnston Island in the Pacific Ocean, Aberdeen, Md., Newport, Ind., and Pine Bluff, Ark.—already have destroyed their chemical weapons and are closed.
After Utah, Alabama and Oregon finish incinerating their supplies, the U.S. will have destroyed 90 percent of its stockpile, he said. The sites in Anniston, Ala., and Umatilla, Ore., are expected to be done by January.
The remaining 10 percent of chemical weapons stockpiles are stored at sites in Pueblo, Colo., and Richmond, Ky.
The U.S. began destroying its stockpiles—once at 31,500 tons—in the 1990s under an international treaty known as the 1993 Chemical Weapons Convention, which requires the destruction of all chemical weapons worldwide.
The chemical agents included mustard gas, VX and sarin, the material used in the deadly 1995 attack on Tokyo’s subway system.
Russia and the U.S. had the two largest stockpiles, Mahall said, adding that Russia’s once exceeded 40,000 tons.
Destruction of the material takes place in a highly guarded facility where the liquid mustard agent is drained and collected in large storage containers that can hold up to 176 gallons. The contents of the containers are then sprayed into a liquid incinerator, and destroyed in temperatures that reach 2,100 degrees.
Mahall said metal projectiles that contained the chemical weapons are burned at 1,500 degrees in a furnace, sanitized by the heat and transported to hazardous materials landfills.
The large bulk containers also must be destroyed in an incinerator. Any remaining chemicals will be burned off in the process, and the metal parts certified “clean” will be sent to smelters, Mahall said.
Opponents of the incineration process, the most commonly used technique, believe it emits dangerous chemicals into the air, such as mercury.
“We want to get rid of them, but how do you do it?” said Craig Williams, who directs a citizens organization called the Chemical Weapons Working Group, which opposes incineration.
He said his group fought to stop the incineration of mustard agents in Utah and at other sites but only succeeded in forcing the Army to add extra charcoal filters to capture more of the mercury released. He said his group also pushed to require that materials be incinerated in smaller quantities.
Mahall said all emissions from the Utah facility are monitored and meet state and federal guidelines.
Two alternative disposal facilities are being built in Colorado and Kentucky, where hot water initially will be used to break down the chemicals before disposal, a method of incineration opponents say is a safer, less toxic process.
