The Pueblo Chemical Agent-Destruction Pilot Plant, or PCAPP, has safely destroyed the stockpile of chemical weapons stored at the U.S. Army Pueblo Chemical Depot, now known as the U.S. Army Chemical Materials Activity-West. Mustard agent was destroyed in the main plant utilizing neutralization followed by biotreatment. After mustard agent neutralization, the resulting product, called hydrolysate, was further processed in the Biotreatment Area. The hydrolysate was fed into the Immobilized Cell Bioreactors to biologically degrade organic materials, producing a saltwater solution. The salt was then removed for disposal and the water was recycled.

The Static Detonation Chamber (SDC) technology was chosen as part of the chemical weapons destruction process at PCAPP. Three electrically heated detonation chambers in the SDC complex augmented the main plant by eliminating a portion of the 4.2-inch mortar rounds and overpacked munitions. SDC technology utilized thermal destruction to destroy mustard agent by detonation or deflagration. An Explosive Destruction System augmented the plant from 2015 to 2018 by destroying a portion of the stockpile that could not be easily destroyed by the main plant’s automated equipment. Non-contaminated energetics removed from the munitions as part of the destruction process were destroyed in the Anniston, Alabama, SDC unit.

In September 2002, the Bechtel Pueblo Team (BPT) was awarded the systems contract to facilitate the plant through all of the project stages — design, construction, systemization, pilot testing, operations and closure. In May 2018, the contract was amended to include the SDC complex. Destruction operations were completed in the main plant June 16, 2023, and in the SDC complex June 22, 2023.

The Program Executive Office, Assembled Chemical Weapons Alternatives program, known as PEO ACWA, is the Department of Defense agency responsible for completing stockpile destruction operations by the Chemical Weapons Convention treaty commitment of Sept. 30, 2023. PEO ACWA will continue to prioritize the safety of the workforce, community and environment throughout the closure process.