Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services,

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... torate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. (reproduction) toxicities of TNT or RDX to E. crypticus, and to generate ecotoxicological benchmarks for developing the ecological soil screening levels (Eco-SSLs) for risk assessments of contaminated soils. Soils with a wide range of physicochemical parameters included: Teller sandy loam (TSL), Sassafras sandy loam (SSL), Richfield clay loam (RCL), Kirkland clay loam (KCL), and Webster clay loam (WCL). Reproduction toxicity of TNT weathered-and-aged in soil, based on EC 50 values, correlated strongly with soil organic matter and clay contents. The order of soil toxicity (from greatest to least) was: TSL > SSL > KCL = RCL > WCL. RDX was less toxic to E. crypticus compared with TNT in the same soil types. RDX toxicity for E. crypticus was greater in sandy loam soils compared with clay loam soils. Toxicity benchmarks established in TSL and SSL will be submitted to the U.S. Environmental Protection Agency Eco-SSL Workgroup for use in developing soil invertebrate-based Eco-SSLs for TNT and RDX.