The March 5 approval of a permit modification by Colorado regulators enables Pueblo plant workers to start ending the plant’s chemical-agent monitoring process, which began nearly a decade ago.

“The approval of B076 was a significant milestone and a huge step for the project,” said Bryan Greasor, deputy plant manager, Pueblo Bechtel Team. “On the road to closure and mission completion, it was a critical accomplishment that we were able to demonstrate the agent had been totally removed in that area.”

Prior to completion of the stockpile destruction in June of 2023, the Enhanced Reconfiguration Building (ERB) processed munitions filled with mustard agent in three Explosion Containment Rooms, each with a Projectile/Mortar Disassembly (PMD), which removed the munition’s energetics and explosive parts.

The authorization allowed for the removal of 24 Miniature Continuous Air Monitoring Systems (MINICAMS) and two Depot Area Air Monitoring Systems stations in the ERB, where equipment disassembly and removal work were completed in March. With removal of the PMD processing lines, control room operators no longer were experiencing agent alarms and, therefore, not collecting associated data needed to generate compliance reports on agent levels. MINICAMS monitoring of ERB rooms remains in place to support pending closure activities to discontinue and remove the plant’s ventilation system.

Next steps in the reduction of monitoring will include the remaining stations in the ERB, followed by the Agent Processing Building and the Agent Filtration Area with the goal that all agent monitoring will be complete by the end of 2025.

Greasor said removal of a portion of the ERB monitoring system was particularly satisfying as it marked success in terms of proving the absence of agent for areas that previously supported processing and agent destruction operations.

“We demonstrated to state regulators that we met the requirements to take that system offline in the ERB, since the presence of agent had been eliminated,” he said.