PUEBLO, Colo.—Behind a double row of fences deep inside the Army’s Pueblo Chemical Depot, 780,000 shells filled with toxic mustard agent are stored in earth-covered bunkers.
Mustard can maim or even kill, causing blisters on skin, scars on the eyes and inflammation in airways. If there’s any question about the nature of security here, a red-lettered sign is explicit: “Use of deadly force authorized.”
In about five years, a highly automated plant at the depot will begin destroying the shells. Until then, they’re stored at the 23,000-acre depot about 10 miles east of Pueblo and 100 miles south of Denver.
The Army doesn’t discuss depot security, but armed soldiers check IDs at the outer gate. Several miles inside, guards at another checkpoint verify IDs again. A few miles past that stands the double fence surrounding about 100 bunkers containing the mustard.
Anyone entering the inner compound—including Lt. Col. Robert C. Wittig, the depot commander—must pass one-by-one through a turnstile in the outer fence, cross the no man’s land between fences and enter a blockhouse, where guards conduct searches with an electronic wand.
Visitors must surrender their ID and any lighters or weapons. Vehicles are searched—even those with government plates, assigned to the depot—and a mirror is rolled underneath.
The process is repeated when visitors leave, and their possessions are returned.
Inside the bunkers, the slender gray shells are stacked on pallets or stored boxes. Although many are more than 50 years old, they look new. Wittig credits the depot’s dry climate and relatively moderate temperatures.
“Our munitions here look like they were just manufactured,” he said. “They’re really in great condition.”
The bunkers, called igloos, are made of 12- to 18-inch-thick reinforced concrete covered with a deep mound of earth.
Crews periodically enter the igloos for visual inspections. Unless the air inside is being monitored by one of the depot’s mobile labs, crew members must wear a gas mask even to approach the door from outside.
The mobile labs make regular checks on the igloos, drawing air from inside through hoses to vapor-detecting instruments.
“If you would imagine 115 pennies in a billion dollars worth of pennies, that’s the detection level that we’re at,” Wittig said.
If a leak is detected, crews cover each stack of shells with a shroud and test the air beneath it, gradually zeroing in on the offender. That can take weeks.
“Our last leaker was in an igloo that had over 17,000 munitions in it, and it was a tablespoon-size spill on one of the munitions,” Wittig said.
Leaking shells are sealed inside a container and stored in a separate igloo. Depot officials say they have identified 96 leaking shells since 1973.
The Colorado Department of Public Health and Environment says the Army’s monitoring and detection levels aren’t sufficient. Besides its other dangers, mustard can cause cancer, and the state says exposure to even low levels can threaten depot workers and the public.
The health department sued the Army last year to force stricter monitoring. Settlement talks are under way.
Some depot workers have suffered respiratory or skin exposure to mustard, said Chuck Sprague, a depot spokesman. None have died, and there have been no exposure incidents in the past 15 years, he said.
The U.S. is obligated by treaty to destroy all its mustard agent. Much of it is being incinerated, but the 2,600 tons at Pueblo and more at the Blue Grass Army Depot in Kentucky will use a process that chemically neutralizes the mustard. Blue Grass has a total of 523 tons of mustard and nerve agents, but no breakdown was available.
The Pueblo plant, now under construction, is expected to start running in 2015 and finish in 2017.
It will dismantle the shells, neutralize the mustard in water and then add bacteria to digest and convert the remaining chemicals. The eventual outcome is a dry “salt cake” that can be disposed of at a hazardous waste dump.
The Blue Grass plant, expected to be online by 2018 and finished by 2021, will use a different process because its stockpile includes nerve agent, which isn’t well-suited to the bacteria technique.
Most of the Pueblo depot will close after all the mustard is destroyed, and what happens to the site is undecided.
In the interim, hundreds of igloos outside the chemical area are being used to store everything from criminal evidence to wine to collector cars.
The igloos are leased to governments, businesses and individuals, said Chuck Finley of the Pueblo Depot Activity Development Authority, which oversees leasing buildings that the Army doesn’t’ need.
“I’ve personally seen some big honking muscle cars, at least one Corvette,” Finley said, and “a cute little red MG.”
