The last chemical munition in the declared U.S. stockpile was destroyed July 7, 2023. The facilities are in the closure phase and are following procedures outlined in U.S. Public Law and the relevant environmental permits. Please visit https://www.peoacwa.army.mil/pcapp/ for the most recent information.
The Pueblo Chemical Agent-Destruction Pilot Plant, or PCAPP, is safely destroying a stockpile of chemical weapons currently in storage at the U.S. Army Pueblo Chemical Depot.
After munitions have been drained and rinsed to remove the mustard agent for neutralization, the Munitions Treatment Unit (MTU) completes the decontamination of munition bodies. To do so, it elevates the temperature of the munitions to at least 1,000 degrees Fahrenheit (537.8 degrees Celsius) for at least 15 minutes.
Two MTUs are used at the PCAPP facility and are both located in the Agent Processing Building (APB). Each MTU is approximately 90 feet (27.4 meters) long and 10 feet (3 meters) wide. The MTUs are designed to process 4.2-inch mortar rounds (60/hour).
Drained mortar rounds are fed to the MTUs by robots. To ensure that full munitions are not placed into the MTU, each one is weighed in the Munitions Washout System (MWS) Room. Munitions are then carried on a conveyor belt, which travels slowly, through the MTU. Individual munitions take more than an hour to pass through the MTU.
The heated portion of the MTU is divided into six zones. The temperature of the munitions increases at a controlled rate and then maintained to complete the decontamination process. A cooling section follows the heating zones to reduce the temperature of munitions and the belt conveyor.
Decontaminated mortar rounds exit the cooling section of the MTU. Gases from the MTU are discharged to the PCAPP off-gas treatment system. Decontaminated munition bodies are deposited into containers to await off-site shipping.
A portion of the mortar rounds will be safely destroyed in PCAPP’s Static Detonation Chamber units using a thermal destruction method.
The Program Executive Office, Assembled Chemical Weapons Alternatives is responsible for completing stockpile destruction operations by the Chemical Weapons Convention treaty commitment of Sept. 30, 2023.
