Defense Environment Alert
April 23, 2002

ARMY ISSUES FINAL ENVIRONMENTAL IMPACT ANALYSIS FOR PUEBLO

The Army April 17 announced the release of its final environmental impact statement (EIS) examining the impacts of four technologies for the destruction of stockpiled chemical weapons stored in Pueblo, CO. The final document lists neutralization followed by biodegradation as the agency's preferred destruction method -- as endorsed by DOD's acquisition chief late last month (Defense Environment Alert, April 9, p9).

The 54 1 -page final EIS assesses the potential environmental impacts of designing, constructing, operating and closing a facility to destroy the 2,611 tons of mustard agent-filled munitions at Pueblo. In addition to the neutralization/blodegradation method, the Army examined a no action alternative and three other technologies: baseline incineration, modified baseline incineration, and neutralization followed by supercritical water oxidation (SCWO). The final EIS is available on InsideEPA. com. Seepage 2 for details.

"The results of the analyses presented in this [final EIS] show that any of the four chemical munitions destruction alternatives would be environmentally acceptable for destruction of the stockpile at Pueblo Chemical Depot," the EIS' executive summary says.

In studying the impacts, the Arrny found that neutralization/biodegradation would use less water than either type of incineration, but more than SCWO. Neutralizationibiodegradation would use 5.7 million gallons per year, the EIS says.

None of the destruction facilities evaluated would be expected to exceed national ambient air quality standards and state ambient air quality standards, the summary says. "Operation of an incineration facility would involve low emissions levels with no exceedances of standards expected," it says, adding, "A neutralization facility would not involve use of an incinerator. However, neutralization would include stacks for process steam, boilers, diesel generators, and the SCWO or biotreatment areas." A chart in the document lists lower emissions per year from neutralization/biotreatment than for incineration methods for a number of pollutants. These include nitrogen oxide, sulfur dioxide, carbon monoxide, particulate matter less than 10 micrometers in diameter and less than 2.5 micrometers, and hydrocarbons. Neutralization/biodegradation, however, would have slightly higher volatile organic compounds, it says.

Impacts would be about the same for any of the destruction facilities, should an uncontrolled accident such as an aircraft crash occur, the summary says.

Separate from the EIS, a high-level DOD board reviewed the technologies, and in its deliberations, it determined that neutralization/biodegradation was the preferred method because the Pueblo community favored it, and because the Army was more likely to accelerate the destruction process using it than the other technologies.