RICHMOND — For the second time in less than two weeks, Army employees detected a mustard agent leak Wednesday at Blue Grass Army Depot.
The mustard was detected at extremely low levels and confined to the interior of the igloo in which it is stored.
The leak occurred in a different storage igloo than the leak detected July 28. The agent poses no threat to the community or environment, according to Blue Grass Chemical Activity, the agency responsible for the storage and monitoring of chemical weapons at the depot.
Mustard is stored in 155mm artillery shells inside four storage igloos. Officials were searching for the source of the most recent leak Wednesday evening. The task can take several days or weeks because there are thousands of shells in the storage igloos.
Employees found the shell responsible for the July leak Wednesday afternoon, said Richard Sloan, spokesman for Blue Grass Chemical Activity. The shell was placed in a leakproof steel container and will be moved to an igloo with similar containers.
Mustard agent is a colorless, odorless liquid that causes blisters. It was first used for chemical warfare in World War I, according to Assembled Chemical Weapons Alternatives, the agency responsible for destruction of the depot's chemical weapons stockpile.
Mustard is less dangerous than nerve agents VX and sarin, the two other chemical weapons stored at the depot, Sloan said.
Officials don't know what caused the leaks. But the warm weather might have had some effect, Sloan said.
The mustard freezes at 56 degrees, the temperature of the interior of an igloo during cooler seasons. The temperature inside the igloo rises in the summer and the mustard begins to thaw, which builds pressure inside the shell, Sloan said.
The result is a “little burp,” or leak, when the shell relieves the pressure, Sloan said.
The number of leaks hasn't increased over the years, Sloan said. The last mustard leak occurred in 2005.
“We've had some good years where none of the shells leaked,” Sloan said. “But they have in the past and we can only expect that there will be some in the future.”
The igloos that hold mustard are checked weekly.
Sloan said the most recent leak occurred within the past six days.
The igloos with the leaking shells are now checked daily.
Chemical weapons at the depot are set to be destroyed by 2017. Construction of the Blue Grass Chemical Agent Pilot Plant, where the weapons will be destroyed, is progressing steadily, said Dave Easter, spokesman for Assembled Chemical Weapons Alternatives.
The mustard leaks don't have much bearing on the progress of the plant, Easter said.
Everybody would like the construction to move faster, “but you're still limited by time, and you're still limited by money,” Easter said.
Craig Williams, director of the Chemical Weapons Working Group, said he was not worried about the latest round of leaks.
“It doesn't cause me any concern because the weapons are old and you're going to have these kinds of things,” he said. “The important thing, I think, is not to see a trend of more leakers over time.”