Mustard vapor detected at Pueblo Chemical Depot

Workers as the Pueblo Chemical Depot in Pueblo, Colo., placed an air filtering device on one of the facility's earth-covered igloos on Tuesday afternoon after detecting mustard vapor during routine monitoring.

Close to 100 regularly monitored igloos in the depot's G Block hold 780,000 artillery shells and mortar rounds that contain a total of 2,611 tons of mustard agent. Some of the weapons, which are decades old, have leaked and others have expelled small traces of gas over the years, The Pueblo Chieftain reports.

PCD crews will enter the igloo this morning to find the source of the vapor. Weapons that are found to be leaking are placed in steel cylinders.

All of the weapons at the base are scheduled to be destroyed through water neutralization but over 500 overpacked ones must be destroyed through another method for safety reasons.

Bob Kennemer, a spokesman for the weapons destruction outreach program, told The Pueblo Chieftain that county and state officials were notified of Tuesday's discovery.

According to the U.S. Army Chemical Materials Agency, PCD is one of five Army installations in the United States that currently store chemical weapons. The depot's missions have shifted and expanded since it was created in 1942. The installation consists of approximately 23,000 acres.