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Guide for Characterization of Sites Contaminated with Energetic Materials
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performed on-site, they provide immediate results to assess any potential risks.
The colorimetric method should be employed first, since it is relatively easier to
estimate initial concentrations and it is not as selective as the immunoassay tests.
High levels of contamination will lead to intensively colored extracts that give an
approximation of the dilution factor required to reach the analytical range. A
specific protocol for use of the colorimetric methods for high-level samples has
been developed (Jenkins et al. 1996b, Hewitt et al. 2001b).
If levels higher than 10% by weight are encountered, additional safety pre-
cautions must be implemented. The most important safety precaution is to mini-
mize exposure, which involves reducing the number of workers exposed to the
hazardous situation and limiting the duration of exposure on site. To reduce the
hazard at explosives-contaminated sites, all mechanical operations should be
carried out on materials that have been diluted to a wet slurry. If necessary, water
should be added to the soil to achieve the desired moisture content. Water desen-
sitizes the explosive by phlegmatizing it and reducing heat and friction. The
drawback of adding water is the possibility of leaching more explosives to the
groundwater. However, this is of minimal environmental impact compared with
the leaching created by rainfall that has already occurred and ensures the safety
of the personnel who will have to manipulate these soils. Other safety precau-
tions that must be taken include the use of non-sparking tools (i.e., non-sparking
beryllium tools), conductive, grounded plastics, and no-screw-top bottles that
have been developed for the handling of explosives.
If operations involving mechanical shoveling are required, remotely con-
trolled operations offer the best protection. If this is not possible, armored safety
glass must be installed in the operator compartment. Drilling operations should
only be permitted after removing the soil layer that is contaminated above the
safety level. Drilling operations may then be performed. Equipment used during
treatment of explosives must have sealed bearings and shielded electrical
junction boxes. Finally, the equipment must also be decontaminated frequently to
prevent the build-up of explosive dust.
If contamination is above the 10% limit in the soil samples, the contaminated
material should be blended and screened to dilute and produce a homogeneous
mixture below the limit. This dilution is not a remedial action by itself but a
safety measure that will allow the safe handling, storing and shipping of samples.
Blending should be carried out precisely in order to calculate the initial concen-
tration that was present in the sample. If the soil were not diluted, the transport of
the samples would require the same safety waiver as that required for transport-
ing pure secondary explosive material.
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