Description: The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility in Waverly, Nebraska, from 1952 to 1974. During this time, the grain fumigant '80/20' (carbon tetrachloride/carbon disulfide) was used to preserve stored grain. In 1982, sampling by the U.S. Environmental Protection Agency (EPA) found carbon tetrachloride contamination in the town's groundwater. After an investigation of the contaminant distribution, the site was placed on the National Priority List (NPL) in 1986, and the CCC/USDA accepted responsibility for the contamination. An Interagency Compliance Agreement between the EPA and the CCC/USDA was finalized in May 1988 (EPA 1990). The EPA (Woodward-Clyde Consultants, contractor) started immediate cleanup efforts in 1987 with the installation of an air stripper, a soil vapor extraction system, a groundwater extraction well, and groundwater and soil gas monitoring wells (Woodward-Clyde 1986, 1988a,b). After the EPA issued its Record of Decision (ROD; EPA 1990), the CCC/USDA (Argonne National Laboratory, contractor) took over operation of the treatment systems. The CCC/USDA conducted a site investigation (Argonne 1991, 1992a,b), during which a carbon tetrachloride plume in groundwater was discovered northeast of the former facility. This plume was not being captured by the existing groundwater extraction system. The remediation system was modified in 1994 (Argonne 1993) with the installation of a second groundwater extraction well to contain the contamination further. Subsequently, a detailed evaluation of the system resulted in a recommendation to pump only the second well to conserve water in the aquifer (Argonne 1995). Sampling and analysis after implementation of this recommendation showed continued decreases in the extent and concentrations of the contamination with only one well pumping (Argonne 1999). The CCC/USDA issued quarterly monitoring reports from 1988 to 2009. Complete documentation of the CCC/USDA characterization and remediation efforts, including the quarterly monitoring reports, is on the compact ...
Date: June 29, 2012
Creator: LaFreniere, L. M.
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