On Sept. 7, 2016, workers at PCAPP began a campaign to destroy nearly 300,000 World War II-era 155mm projectiles, stored at the U.S. Army Pueblo Chemical Depot, which contained approximately 12 pounds of mustard agent each. Almost exactly four years later, on Sept. 5, that campaign was completed.

Colorado Chemical Demilitarization Citizens’ Advisory Commission members commented on the recent completion of the Pueblo Chemical Agent-Destruction Pilot Plant’s 155mm projectile campaign.

“The completion of the 155mm demilitarization is a major milestone at PCAPP and the Pueblo community,” said Irene Kornelly, chair, CAC. “Never again can these weapons be used to harm civilization.”

More than 780,000 munitions were in the original Colorado stockpile, and about two-thirds of that stockpile agent has now been destroyed.

“Pueblo has carried this burden for nearly 80 years, sustaining the national defense policy,” said Jeff Chostner, CAC member. “It is wonderful for the public to see this process coming to a close.”

Destruction involved a two-step process. Mustard agent molecules were neutralized with hot water, resulting in a chemical compound called hydrolysate, a common industrial chemical that is biodegradable. The hydrolysate was then broken down into salts, water and organics using living microbes.

“I’m really glad to see the destruction of two-thirds (of agent) complete and especially happy that it has been done safely,” said John Norton, CAC member. “I’m also impressed that the program has worked as planned from neutralization to biotreatment.”

“Overall the 155mm projectiles were destroyed in a safe and professional way by the PCAPP team,” added Ken Griffin, CAC member.

The next munitions campaign at PCAPP is the destruction of 105mm projectiles, which each contain 3 pounds of mustard agent. That work is tentatively scheduled to begin in late November.

“We are very excited to reach the end of the 155mm campaign,” said Terry Hart, vice chair, CAC. “This is a huge milestone for this project that is critically important for the Pueblo community and our nation. Hard work by all involved, especially our dedicated staff at PCAPP, has gotten us to this point and we are now primed to complete the rest of the mission.”