Factors Effecting the Fate and Transport of CL-20 in the Vadose Zone and Groundwater

Abstract : Hexanitrohexaazaisowurtzitane (CL-20, HNIW) is a recently developed energetic material that releases more energy on ignition and is more stable to accidental detonation than currently used energetic materials. It is expected to replace many of the energetic materials currently being used by the DoD. Hazardous wastes associated with the life cycle of DoD energetic materials currently constitute over 40% of hazardous waste produced by DoD operations. However, very little is known on the fate and transport of CL-20 in the environment. The objective of this project is to provide data on the environmental fate and transport of CL-20 in the subsurface that can be directly inputted into contaminant transport models to assess and manage environmental risk from CL-20. The subsurface is one of the areas that have proved most problematic in the production and use (firing ranges) of energetic materials. More specifically, we identified the biotic and abiotic mechanisms that determine the fate of CL-20 in the subsurface environment, determine the rates of the significant reactions under conditions of weathering and aqueous transport, and provide this information in a format that can be inputted into existing groundwater/contaminant models. This report represents the final progress report for SERDP project CP-1255 entitled "Factors Effecting the Fate and Transport of CL-20 in the Vadose Zone and Groundwater" for the period March 2002 to May 2005. This laboratory study of CL-20 subsurface fate involves research at Pacific Northwest National Laboratory, the U.S. Army Engineer Research & Development Center, Waterways Experiment Station, and the University of Arizona.