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
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 184.108.40.206 to 220.127.116.11.