State regulators approved the full processing rate for the destruction of HT mustard-agent 4.2-inch mortar rounds in the main plant Jan. 20.

“Getting the HTs into the main plant will go a long way toward achieving our goal of completing the stockpile destruction by the September deadline,” said Patrick Sullivan, research scientist, PCAPP. “Destroying the HTs first will allow us to be productive while we find a solution for washing out the HD mortar rounds, which remain in testing protocol.”

With the approval from the Colorado Department of Public Health and Environment, or CDPHE, crews can begin to destroy the more than 18,000 HT mustard-agent 4.2-inch mortar rounds that remain. Destruction operations for the 47,000 HD 4.2-inch mortar rounds have yet to receive CDPHE consent as crews are still in testing to resolve the issue of residue lingering in the base of the mortars.

“The team will submit a revised test plan and parameters for the HD munitions in the coming weeks,” Sullivan said.

Pueblo crews began destroying 4.2-inch mortar rounds in the main plant using an improved technology Dec. 1. The Improved Cavity Access Machine, or ICAM, design is based on existing Cavity Access Machine technology, robotic equipment that turns projectiles upside-down and hydraulically collapses the internal components to wash out mustard agent. The ICAMs use a vacuum-powered probe to remove agent.

The Pueblo plant is on track to eliminate the remaining chemical weapons stockpile stored at the U.S. Army Pueblo Chemical Depot by Sept. 30, 2023, as required by the Chemical Weapons Convention treaty.