Largest U.S. cache of chemical weapons to be destroyed

Dan Elliott
Associated Press

Denver — The U.S. Army is about to begin destroying the nation’s largest remaining stockpile of chemical weapons.

The first container of mustard agent was moved into an airtight containment building at Pueblo Chemical Depot in Colorado on Wednesday, and crews expected to open it and neutralize it later in the day.

The depot has about 2,600 tons of mustard agent, most of it contained in about 780,000 shells. It’s being destroyed under an international treaty banning all chemical weapons.

It will take four years to destroy the Pueblo stockpile. About 1,400 damaged shells will be processed first.

An additional 523 tons of mustard and deadly nerve agents are stored at Blue Grass Army Depot in Kentucky. Blue Grass isn’t expected to start destroying its weapons until 2016 or 2017, finishing in 2023.