No abstract

Field sampling experiments were conducted at the firing range at Fort Polk, Louisiana. The objectives were to determine the spatial distribution and best approach for collecting representative surface soil samples to estimate mean concentrations of residues of high explosives at two types of potential source zones: (1) an area near a low-order [partial] detonation of an 81-mm mortar and (2) an artillery/mortar target. Soil sampling near the low-order detonation revealed the presence of potential "hot spots" and showed that the concentrations of RDX and TNT ranged over five orders of magnitude. The range of concentrations was reduced to a factor of about 60 when randomly collected 25-increment composite samples were collected within this area. The range reduced further to about a factor of three for four simulated (i.e., existing discrete values) 25-increment systematically derived composite samples. Thus a vast improvement in the repeatability of replicate samples can be achieved using composite sampling approaches. Composite samples collected around a target showed that the distribution of energetic residues was random and overall the concentrations were much lower than around the partially detonated round. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN IT IS NO LONGER NEEDED. DO NOT RETURN TO THE ORIGINATOR.

Abstract:Military live-fire training missions utilize a variety of energetic materials that are never completely consumed during firing. In February 2007, the U.S. Army Cold Regions Research and Engineering Laboratory teamed with the Vermont National Guard at Camp Ethan Allen to conduct tests to determine the propellant residues deposition related to the firing of small arms. Samples were collected from the snow surface at the firing points for 5.56-, 7.62-, 9-, and 12.7-mm (0.50-cal.) weapons, as well as from areas up to 40 m downrange. Six tests were conducted utilizing five weapon systems. Samples were analyzed to derive an estimate of the mass of unreacted energetics deposited from each activity. The areas sampled at the 5.56-mm firing points contained 1.8 and 1.3 mg NG (1.1% and 0.80% original mass) per round, the 7.62-mm firing point contained 1.5 mg NG and 0.0018-mg DNT (0.56% and 0.048% original mass) per round, the 9-mm firing point contained 2.1-mg NG (5.4% original mass) per round, and the 12.7-mm firing points averaged 11 mg NG (0.73% original mass) per round. These results indicate that although consumption rates for this class of ammunition are high, accumulation of energetic residues should be considered for range sustainment programs.