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 (PCAPP) is safely and efficiently destroying chemical weapons stored at the U.S. Army Pueblo Chemical Depot (PCD). The mustard agent in the munitions is destroyed by neutralization followed by biotreatment.

An Improved Cavity Access Machine (ICAM) is a component of the Munitions Washout System (MWS). The ICAM allows 4.2-inch mortar rounds to be processed for destruction in the main plant. These rounds are currently being destroyed in the Static Detonation Chamber (SDC) complex, and those efforts will also continue.

The first two CAM configurations relied upon gravity to remove chemical agent from 105mm and 155mm projectiles. The MWS robotic arm placed the projectile upside-down into the CAM. The CAM operated by hydraulically pushing the burster well (a tube in the middle of the projectile) into the munition. The collapsed burster well created an opening for agent to drain from the munition, which was then rinsed.

With the new ICAM system installed in the fall of 2022, the MWS processes 4.2-inch mortar rounds using a robotic arm to place a mortar round into the machines. The first step removes the burster well from the mortar round and rinses it. The ICAM moves the burster well to a punch site, where holes are punched to vent any pressure while the munition body goes through a final thermal treatment process. The second step of the ICAM takes the mortar round to a wash water station, where a wash wand, or drain tube, vacuums agent from the upright mortar round. Wash water is then sprayed inside the mortar round to rinse out any residual agent. The ICAM lifts and rotates the mortar round to ensure agent removal from all interior surfaces. Chemical agent and rinse water are piped to another area of the plant where agent is neutralized. After the rinse is complete, the punched burster well is returned to the mortar body. The robot then removes the mortar shell from the ICAM and transfers it to the Munitions Treatment Unit for final processing.

The ICAMs were developed using lessons learned from 105mm projectile CAMs, resulting in greater reliability, safety, and less maintenance in contaminated areas. The SDC units are also being used to destroy 4.2-inch mortar rounds and problematic 105mm and 155mm projectiles, which were deemed unsuitable for processing in the main plant.

The SDC complex at PCAPP remains essential for the ability to process munitions regardless of their configuration or physical condition, reducing the manual handling of such chemical weapons that were overpacked, or placed in sealed containers, for various reasons.

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. U.S. public law mandates stockpile destruction by Dec. 31, 2023.