The U.S. Army operates explosives manufacturing plants to produce various forms of explosives used in military ordnance. Manufacturing activities at such plants result in the production of organic wastewaters that contain both explosive residues and other organic chemicals. Past waste handling practices at such plants commonly included the use of unlined lagoons or pits for containing process waters. As a result of these past practices, some explosive residues may leach through the soil and contaminate ground water.

The U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) and the Missouri River Division (MRD) have been involved with numerous explosives-contaminated sites. They have compiled data on the frequency of nitroaromatics and nitramines detected in explosives-contaminated soils from Army sites. TNT is the most common contaminant, occurring in approximately 80% of the soil samples found to be contaminated with explosives. Trinitrobenzene (TNB), which is a photochemical decomposition product of TNT, was found in between 40 and 50% of these soils. Dinitrobenzene (DNB), 2,4-dinitrotoluene (2,4-DNT), and 2,6-DNT, which are impurities in production-grade TNT, were found in less than 40% of the soils.

As mentioned earlier, safety concerns are an important consideration when discussing remediation of explosives-contaminated soils, sediments, and sludges. Spark and static electricity hazards must be eliminated. Nonsparking tools, conductive and grounded plastic, and no-screw tops, which were developed for manufacturing explosives, are standard equipment at explosive waste sites. For example, nonsparking beryllium tools are used instead of ferrous tools.

If contamination is above the 10% limit in some areas of a site, the contaminated material could be blended and screened to dilute the contamination and produce a homogenous mixture below the 10% limit. This blending is not by itself a remedial action but a safety precaution; soils containing less than 10% secondary explosives by weight occasionally experience localized detonations, but generally resist widespread propagation. Foreign objects and unexploded ordnance within the contaminated soil often impede the blending process and require specialized unexploded ordnance management procedures.

Once blending is completed, soil treatments such as incineration and bioremediation can proceed. Equipment used in treatment must have sealed bearings and shielded electrical junction boxes. Equipment also must be decontaminated frequently to prevent the buildup of explosive dust.

Biological, thermal, and other (such as reuse/recycle) treatment technologies are available to treat explosives-contaminated soils. These technologies are briefly discussed in Sections 2.10.2.1 to 2.10.2.3.