Overview

The Program Executive Office, Assembled Chemical Weapons Alternatives (PEO ACWA), the U.S. Army Pueblo Chemical Depot and the surrounding communities worked together to select neutralization followed by biotreatment to destroy the chemical weapons stored at the depot. PEO ACWA 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.

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.

Pilot Testing

Pilot testing in the main plant began on Sept. 7, 2016, with the gradual introduction of actual agent-filled munitions into the automated system.

Pilot testing in the main plant is complete and in compliance with all safety requirements. Environmental permits are pending. The remaining agent-filled projectiles are being destroyed.

Operations

Operations at the Pueblo plant reflect that the plant is performing as it was designed, with munitions being destroyed using neutralization followed by biotreatment. The main plant functions as a fully operational facility under a Resource Conservation and Recovery Act Part B Permit.