An Explosion Containment Room is back in operation at the Pueblo Chemical Agent-Destruction Pilot Plant after cleanup that followed the discovery of leaked mustard agent on a munition earlier this year.

“This team continued to find ways to improve recovery efforts, including using steam cleaners and decontamination solutions to aid in getting all that pervasive agent removed,” said Kim Jackson, plant manager.

Similar to motor oil, mustard agent is viscous and difficult to remove, Jackson said. The intensive effort by workers wearing protective equipment required a mechanical rebuild of the room’s processing line after decontamination was completed.

In February, an alert control room worker monitoring camera feeds noticed signs of leaked liquid on a 155mm projectile at the Nose Closure Removal Station and stopped processing in the ECR – one of three at PCAPP – before any further areas could be contaminated. Plant officials said this prevented work from being delayed by a wider cleanup of other stations.

The ECR is an area where mustard agent-filled munitions, stored at the Pueblo Chemical Depot since the 1950s, have their energetic components removed through various stations. The munitions are then drained, and the agent inside destroyed through a neutralization followed by biotreament process. Some munitions may have corrosion or other issues; these are stored for later destruction in the Static Detonation Chambers, currently under construction in Europe and awaiting installation at PCAPP later this year.

As of late April, PCAPP’s acting site project manager, Walton Levi, reported the facility had destroyed 28% of the remaining mustard agent in its stockpile.