Constructed decades apart, earth-covered magazines safely store chemical munitions at the U.S. Army Pueblo Chemical Depot and the Pueblo Chemical Agent-Destruction Pilot Plant.

“The igloos are protective against fire, lightning, wind and rain,” said Hawkins Conrad, PCAPP liaison officer, PCD.

Depot storage igloos, made of steel-reinforced concrete walls and floors and heavy metal doors, have safely stored chemical agent-filled munitions since 1952, Conrad said.

Once transferred to PCAPP, the munitions await destruction in one of three Munitions Service Magazines. Although slightly larger than the depot’s bunkers, the pilot plant magazines are hardened to igloo specifications. They differ only in door design—a rolling door instead of the depot’s hinged door, said Don Jespersen, quality assurance specialist/ammunition surveillance, PCAPP.

The igloos and magazines have vents built into the front door and rear stack for airflow. The vents are equipped with a temperature-controlled damper that closes the airway, preventing flames from entering the magazine in the event of a fire. Both types of magazines have lightning protection systems, which would divert energy into the ground instead of the magazine, Jespersen said.

About two feet of dirt and vegetation covers both the depot igloos and PCAPP magazines, suppressing a blast, should one occur. The earth cover also moderates the internal temperature of the magazine, maintaining 50 degrees Fahrenheit during winter months and 60 degrees Fahrenheit during summer months, Jespersen said.

“Residents of the communities surrounding the stockpile can take comfort in knowing the chemical weapons are safe and secure,” Jespersen said.