The maintenance of a well-trained military requires extensive and continual training in the handling and firing of ordnance. Because the detonation, or failed detonation, of ordnance may result in the release of unexploded energetic compounds (e.g., TNT, RDX, and HMX), technologies are needed to protect sensitive environmental resources near and underlying live fire ranges.

The objective of this project was to identify and evaluate low-cost additives that could be applied at active live fire ranges to prevent the migration of energetic compounds to underlying groundwater. Researchers evaluated the use of sorbents that bind the energetic compounds and biostimulants that promote their biodegradation.

Conceptual model of the role of sorption and biodegradation in preventing the migration of energetic compounds to groundwater. Important processes include reversible and irreversible sorption and partial and complete biodegradation

Energetic compounds such as RDX, HMX, and TNT are known to be biodegraded in the environment, and limited biotransformation at times allows them to sorb strongly to organic material in soils. Thus, it was proposed that low-cost additives could stimulate biotransformation and/or sorption of the energetic compounds at the soil surface, thereby slowing their migration to groundwater. Soil slurry and unsaturated soil microcosm experiments were performed to evaluate the sorption of energetic compounds to several materials, and multiple carbon sources were screened for their ability to stimulate the biotransformation of the energetic compounds. Soil column studies further evaluated the effectiveness of the additives in preventing migration of the energetics through soil.

Results indicated that Sphagnum peat moss as a sorbent and crude soybean oil as a biostimulant was an excellent combination for immobilizing and degrading TNT, RDX, and HMX. A fate and transport model was developed, which indicated that applying a 1-inch layer of this material to the soil surface would reduce the flux of newly created explosive residues to the subsurface by more than 70% in 1 year as compared to no application. Four manuscripts detailing the project’s results have been published.

This project supports the development of sustainable range management procedures, thus protecting environmental resources with minimal interference to training. The most promising additives identified have transitioned to the Environmental Security Technology Certification Program (ESTCP) for full-scale demonstration and validation under ESTCP project ER-200434. (Project Completed – 2004)