Particulate Emissions from U.S. Department of Defense Artillery Backblast Testing

Abstract

There is a dearth of information on dust emissions from sources that are unique to the U.S. Department of Defense testing and training activities. However, accurate emissions factors are needed for these sources so that military installations can prepare accurate particulate matter (PM) emission inventories. One such source, coarse and fine PM (PM 10 and PM 2.5 ) emissions from artillery backblast testing on improved gun positions, was characterized at the Yuma Proving Ground near Yuma, AZ, in October 2005. Fugitive emissions are created by the shockwave from artillery pieces, which ejects dust from the surface on which the artillery is resting. Other contributions of PM can be attributed to the combustion of the propellants. For a 155-mm howitzer firing a range of propellant charges or zones, amounts of emitted PM 10 ranged from ϳ19 g of PM 10 per firing event for a zone 1 charge to 92 g of PM 10 per firing event for a zone 5. The corresponding rates for PM 2.5 were ϳ9 g of PM 2.5 and 49 g of PM 2.5 per firing. The average measured emission rates for PM 10 and PM 2.5 appear to scale with the zone charge value. The measurements show that the estimated annual contributions of PM 10 (52.2 t) and PM 2.5 (28.5 t) from artillery backblast are insignificant in the context of the 2002 U.S. Environment Protection Agency (EPA) PM emission inventory. Using national-level activity data for artillery fire, the most conservative estimate is that backblast would contribute the equivalent of 5 ϫ 10 Ϫ4 % and 1.6 ϫ 10 Ϫ3 % of the annual total PM 10 and PM 2.5 fugitive dust contributions, respectively, based on 2002 EPA inventory data. There are, however, other sources of dust emissions that are unique to DoD activities and for which the PM emission factors are entirely uncharacterized. Despite the dearth of information on dust emissions from these types of sources, the DoD recognizes the need for military installations to prepare accurate PM emission inventories. A number of studies, supported by the Strategic Environmental Research and Development Program, are being carried out to characterize and quantify dust emissions from unique DoD sources, including tracked vehicle movement, rotary-and fixed-winged aircraft, and backblast from firing of high-caliber artillery. INTRODUCTIONIn this paper, we report on the results of a measurement campaign to quantify the emissions of PM 10 and PM with aerodynamic diameter Յ2.5 m (PM 2.5 ) from artillery backblast. Emissions are reported for "improved" sites, where the artillery firing position is located on a surface that has been altered from the native soil material. This alteration can be the addition of gravel to create a more stable surface and may also include the addition of dust suppressants, such as calcium chloride. Emissions from primarily 155-mm artillery pieces firing a range of propellant amounts, designated as zones, were measured using real-time, in situ techniques at the Yuma Proving Ground (YPG) near Yuma. Samples of PM 10 and PM 2.5 were also collected with medium...

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