Defense Environment Alert

an exclusive biweekly report on defense policies for cleanup, compliance and pollution prevention

Vol. 15, No. 11

May 29, 2007

ARMY MOVE TO BURN MERCURY-TAINTED MUSTARD AGENT MAY SET PRECEDENT

The Army is proposing to burn mercury-contaminated mustard blister agent by adding sulfur-impregnated carbon filters onto its incinerators at its Tooele, Utah chemical weapons disposal facility, dismissing citizen activists' push to use a non-incineration method, such as neutralization, for the mercury-affected stocks. The Army's decision at Tooele - long in coming - suggests it will also likely use incineration with carbon filters at its other mustard sites.

Sources with the Army's Chemical Materials Agency (CMA) and at the Tooele site say that the new technique for use at Tooele could serve as a model elsewhere, notably at the Army's Umatilla Chemical Agent Disposal Facility, OR. "We will continue to monitor what happens at Tooele, and apply the lessons learned to other sites," the CMA source says.

Citizen activists have long urged alternatives to incineration for destroying chemical weapons stockpiles, saying other methods are safer and more environmentally protective, but have recently focused on getting the Army to reconsider its plans to incinerate its mustard agent stocks, citing concerns about mercury contamination in some of them (Defense Environment Alert, Sept. 5, 2006, p12). The Chemical Weapons Working Group (CWWG), a national coalition of citizen activists, has pushed for using other destruction methods for the mustard stocks in Anniston, AL; Pine Bluff, AR; Umatilla, OR; and Tooele.

The Army has wrestled with questions over how it would address mustard stocks contaminated with mercury, even saying in recent weeks that an alternative disposal option - neutralization - remained a possibility.

Tooele began incinerating its mustard agent in August 2006 and should complete destruction of its entire chemical weapons stockpile by 2013, spokesmen say, although it so far has set aside those containers of mustard agent contaminated with mercury- At Umatilla, no incineration of mustard has yet taken place due to an ongoing legal challenge brought by the environmental group GASP (Defense Environment Alert. May 1, p15). State environmental regulators are now re-examining proposed incineration procedures for mustard agent on the site under a court order.

The Army is now suggesting using the existing incinerators at Tooele, which would be fitted with the filters to remove mercury, after first using high-pressure hot water treatment to remove solid waste residues inside metal "ton containers" holding the mustard agent. The material removed by hot water treatment would then be incinerated. The Army recently released an environmental assessment on the plan, asserting no environmental risks, and is taking public comment until June 29. Relevant documents are available at !nsideEP4com. See page 2 for details.

The filtration systems would employ an activated sulfur-impregnated carbon (SIC), which would remove mercury from exhaust gases. In its environmental assessment, the Army assumes a working hypothesis that the method will remove 9O% of mercury. Permit modifications under the Resource Conservation and Recovery Act (RCRA) and Clean Air Act will be required from state regulators to implement the new system, the Army says.

A source for the Sierra Club says that although the technology is very efficient, and "could dramatically reduce mercury emissions," it might not be enough to reach regulatory standards if the concentration of mercury in the mustard agent were too high in the first place."

While the Army used neutralization to destroy ton containers of mustard agent at its Aberdeen, MD, site, the CMA source argues it cannot easily retrofit existing incineration plants at other sites to destroy stockpiles using neutralization. The source says that the neutralization of mustard agent at Aberdeen, however, does not set an example for the Tooele or Umatilla sites as the quantities of agent at the Aberdeen facility were much smaller. "You can't change the current configuration," the source says. "The plan is not to change the primary destruction method."

A source with CWWG expresses disappointment over the Army's choice of incineration for the mercury-laced mustard agent at Tooele. "This is what we anticipated. I'm not surprised; there is no turning back from this 'burn everything' mentality that they have," the source says. CWWG in an engineering report issued last year found that neutralization technologies would be "reasonably
feasible" to destroy mustard agent at incinerator sites, but stopped short of recommending that a non-incineration technology be deployed because the Army has declined to release key data.

The CMA source contends that switching to neutralization would involve building entirely new facilities from scratch, resulting in higher costs that would have to be met by higher budget requests from DOD, and lengthy delays. The source explains that "you are talking about designing, permitting, constructing, running and then closing a totally new facility." This would take time, increasing the risks presented by continued storage of aging chemical munitions.