Results of a Microbial Weathering Study of Composted Explosives-Contaminated Soil Obtained from the Umatilla Army Depot Activity, Umatilla, Oregon

Abstract : This report describes the interim results (September 1996 through September 1998) of a Microbial Weathering Study conducted to determine if composted explosives-contaminated soil would leach explosives or explosive by-products. The three-year study was conducted using compost produced during the remediation of an explosives-contaminated site at the U.S. Army's Umatilla Army Depot Activity at Umatilla, Oregon. This compost was shipped to the Tennessee Valley Authority's Environmental Research Facility in Muscle Shoals, Alabama, where the study was conducted. At this juncture, two years' worth of data have been collected. The report concludes that the compost had not leached TNT, but had leached as much as 31.5 and 26.4 ppb of HMX and RDX, respectively. These results suggest that these explosives were not fully mineralized. However, the concentrations leached were well below the state of Oregon's action limit of 30 ppm.