US reaches milestone in destroying mustard agent in Colorado

PUEBLO, Colo. – The Army says it has reached a milestone at a Colorado chemical weapons depot by destroying nearly 300,000 decades-old artillery shells containing mustard agent.

Walton Levi, site project manager of the U.S. Army Pueblo Chemical Depot, made the announcement in a depot publication on Tuesday.

Depot workers destroyed the last of the 155mm World War II-era shells on Saturday. Each shell contained nearly 12 pounds (5.4 kilograms) of mustard agent, which can maim or kill, blistering skin, scarring eyes and inflaming airways.

The plant started operating in 2016 with more than 780,000 munitions in its original stockpile containing 2,500 U.S. tons (2,270 metric tons) of mustard agent. It is eradicating shells under an international treaty banning chemical weapons with a 2023 projected completion date.

Plant technicians will retrofit robots and other systems used to handle and destroy munitions before beginning work to eliminate 105mm projectiles with 3 pounds (1.4 kilograms) each of mustard agent.