Mercury contamination could slow down destruction of chemical stockpile.

THE ARMY HAS destroyed nearly half of the nation's chemical weapons stockpile during the past decade. But completing the second half of the job by the mandated deadline of April 2012 will be tougher than previously expected.

The $36 billion effort to get rid of 30,000 tons of decade-sold chemical agents and munitions got off to a rocky start in 1997, after the United States signed on to the Chemical Weapons Convention treaty. The original deadline of April 2007 proved unrealistic as the Army's plan to build incinerators at nine chemical weapons depots ran into strong opposition by local communities and environmental groups. After it managed to win a string of lawsuits that sought to derail the incinerators, the Army Chemical Materials Agency has so far destroyed 13,000 tons of deadly agents.

"The framers of the treaty underestimated the technical challenges of this program," said Dale A. Ormond, acting director of the Army Chemical Materials Agency.

But environmental, rather than technical, problems once again threaten to slow down the project. At two depots--in Tooele, Utah, and Umatilla, Ore., officials recently discovered that possibly thousands of mustard gas containers may have been contaminated by mercury, and the Army now must find ways to prevent the mercury from being released into the atmosphere when the mustard is destroyed.

Mercury contamination in the mustard gas stockpile is "one of the challenges we see down the road," said Ormond.

CMA is considering various options for how to safely treat the contaminated agents and preclude any emissions of mercury into the atmosphere from the incinerators. The agency is still trying to assess the scope of the problem, Ormond told reporters at a Pentagon news conference.

"The mercury came from some place in the manufacturing process," Ormond said. It is not yet clear how that happened. One theory is that mercuric chloride was used as a catalyst for some forms of mustard. The toxic material could have been shipped to the plant in one-ton containers and those containers may have been back filled with mustard. It is possible that the mercury may have existed in the stockpile, Ormond said. At Tooele alone, there are 6,400 one-ton containers of mustard gas that are being analyzed for mercury contamination. Thousand of agent-loaded projectiles also are being investigated. The depot at Tooele has 40 percent of the nation's chemical stockpile.

Ormond said he is confident that the issue can be resolved so it doesn't hold up the incineration of the mustard, which is much more dangerous than mercury. "The thinking is that the mercury will kill you but the mustard will do it first," he said. Each container holds approximately 1,800 pounds of nerve agents and mustard.

Depending on the extent of the contamination, CMA will examine options on how to get rid of the mercury. The agency likely will adopt some of the technologies used in coal and power plants, where mercury contamination is a huge problem, Ormond said. "It's a matter of adapting the [mercury filter] technology to fit our plants."

In the near term, workers at Tooele will design and install special sulfur-impregnated carbon filters to remove mercury from exhaust generated when containers determined to have elevated concentrations are incinerated.

Another source of concern at CMA is finding better and more economical ways to eliminate so-called secondary waste at the five depots where chemical agents are being destroyed. Secondary waste includes workers' plastic garments, cloths used to clean up spills and other items that have been exposed to chemical agents and must be destroyed. "Our plants don't destroy secondary waste very well or cost effectively," Ormond said. "That's a big issue when we have to close plants.

"We are looking at sending lightly contaminated secondary waste to commercial incinerators ... Some stuff we wouldn't send because it has too much contamination.

"If we can negotiate with state regulators, we can save a lot of money," he added. The chemical demilitarization program has a $1.2 billion annual budget. "Generally the program got the funding it needed," Ormond said. "But occasionally Congress has delayed work due to citizens' concerns. People were unsure if what we were doing was safe."