The Program Executive Office, Assembled Chemical Weapons Alternatives program, the U.S. Army Pueblo Chemical Depot and the surrounding community worked together to select neutralization followed by biotreatment to destroy the chemical weapons stored at the depot.
In September 2002, the Bechtel Pueblo Team was awarded a contract to design, construct, test, operate and close the facility that will utilize this technology: the Pueblo Chemical Agent-Destruction Pilot Plant (PCAPP). Neutralization followed by biotreatment uses hot water to neutralize the chemical agent, effectively destroying the mustard agent molecules. The resulting hydrolysate is mostly water and thiodiglycol, a common industrial chemical that is readily biodegradable. Ordinary sewage treatment bacteria, or microbes, consume the organics in the hydrolysate. Besides being a common phenomenon in nature, the science of using microbes to help dispose of hazardous waste has existed for decades. Sewage treatment facilities across the country use microbes every day to help break down raw sewage.
The first mustard agent-filled munitions were processed through the Pueblo Chemical Agent-Destruction Pilot Plant on Sept. 7, 2016. The gradual introduction of mustard agent-filled munitions into the system initiated the pilot testing phase of operations. Pilot testing will continue until agent destruction is confirmed and all safety requirements and environmental permits are successfully completed. During the pilot test phase, approximately 25 percent of the 155mm stockpile will be destroyed. Upon completion of the pilot testing phase, the plant will transition into full-scale operations