The U.S. Army and EG&G Defense Materials, Inc, Tuesday began a major, unprecedented joint project to sample the contents of Deseret Chemical Depot's (DCD's) stockpile of bulk containers filled with mustard blister agent.

Under the joint sampling project, DCD workers will deliver bulk containers to specially outfitted igloos in the "Area 10" munitions storage location, where EG&G workers will transfer them into sealed glove-box units, allowing operators to safely open them and remove samples for analysis and characterization by site laboratory personnel.

Following sampling, EG&G workers will close and return the containers to DCD personnel for storage according to their contents facilitating their eventual processing. The sampling project is expected to take two-and-a-half to three years to complete. Bulk container disposal operations are expected to begin this summer, targeting for destruction sampled containers identified as having no or low mercury contamination and low solids content.

There are approximately 6,400 mustard agent bulk containers in storage at DCD, located 60 miles southwest of Salt Lake City. Sampling operations will allow individual bulk containers (each containing approximately 1,800 pounds of chemical agent) to be categorized for later disposal.

Some of the mustard bulk containers are known to contain mercury compounds of varying concentrations, as well as solidified material which, over decades of storage, have settled on the containers' interior base. The solids are referred to as "heels," because the solids would remain inside the containers after liquid agent has been drained. While the cause of the mercury contamination is unclear, it is theorized certain bulk containers were not clean when they were filled with mustard agent.

While the number of high mercury-contaminated bulk containers is expected to be relatively small, the sampling is necessary because container processing order will depend on its individual mercury concentration and heel size. It is anticipated the majority of bulk containers will have no or very low mercury content, with no heels of significance, allowing safe and environmentally-protective processing utilizing existing facilities at the Tooele Chemical Agent Disposal Facility (TOCDF) plant.

Initial processing will begin with containers that have low mercury and low heel. During the first year and a half, workers will install special filters to the furnace pollution abatement systems. The addition of these sulfur-impregnated carbon filters will remove mercury from exhaust gases generated when containers determined to contain higher concentrations of mercury, and/or heel are processed later.

The U.S. Army Chemical Materials Agency (CMA) with headquarters at Aberdeen Proving Ground, Md., stores the nation's aging chemical weapons and develops programs aimed at effectively treating and ultimately eliminating chemical warfare materiel. For more information about CMA and its programs, visit www.cma.army.mil