The Associated Press reports that “the U.S. Army plans to start operating a $4.5 billion plant next week that will destroy the nation’s largest remaining stockpile of mustard agent, complying with an international treaty that bans chemical weapons, officials said Wednesday.”

“The largely automated plant at the military’s Pueblo Chemical Depot in southern Colorado will begin destroying about 780,000 chemical-filled artillery shells soon after this weekend, said Greg Mohrman, site manager for the plant. He declined to be specific, citing security concerns and possible last-minute delays.”

“Robots will dismantle the shells, and the plant will use water and bacteria to neutralize the mustard agent, which can maim or kill by damaging skin, the eyes and airways. At full capacity, the facility can destroy an average of 500 shells a day operating around the clock. It’s expected to finish in mid-2020.”