The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), formerly operated a grain storage facility approximately 1,100 ft north of Centralia (Figure 1.2). The CCC/USDA operated this facility from 1949 until 1971. None of the CCC/USDA structures remain. Two additional grain storage facilities currently exist in and near Centralia: the Nemaha County Co-op, approximately 4,000 ft south of the former CCC/USDA facility, and a private grain storage facility near the Don Morris residence, 3,500 ft north of the former CCC/USDA facility. Prior to 1986, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the grain storage industry to preserve grain. In April 1998, the Kansas Department of Health and Environment (KDHE) sampled the domestic well at the Don Morris residence near Centralia (Figure 1.2) as part of the CCC/USDA Private Well Sampling Program, which was initiated to determine whether carbon tetrachloride was present in domestic wells located near former CCC/USDA grain storage facilities in Kansas. Carbon tetrachloride was detected in the Morris well at 19.3 mg/L and confirmed at 25.4 mg/L, both concentrations above the maximum contaminant level (MCL) of 5 mg/L for carbon tetrachloride in drinking water. On the basis …

In September 2005, periodic sampling of groundwater was initiated by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) in the vicinity of a grain storage facility formerly operated by the CCC/USDA at Centralia, Kansas. The sampling at Centralia is being performed on behalf of the CCC/USDA by Argonne National Laboratory, in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE). The objective is to monitor levels of carbon tetrachloride contamination identified in the groundwater at Centralia (Argonne 2003, 2004, 2005a). Under the KDHE-approved Monitoring Plan (Argonne 2005b), the groundwater is being sampled twice yearly (for a recommended period of two years) for analyses for volatile organic compounds (VOCs), as well as measurement of selected geochemical parameters to aid in the evaluation of possible natural contaminant degradation (reductive dechlorination) processes in the subsurface environment. The sampling is presently conducted in a network of 11 monitoring wells and 5 piezometers (Figure 1.1), at locations approved by the KDHE (Argonne 2006a). The results of groundwater sampling and VOCs analyses in September-October 2005, March 2006, and September 2006 were documented previously (Argonne 2006a,b). The results have demonstrated the presence of carbon tetrachloride contamination, at levels …

In September 2005, periodic sampling of groundwater was initiated by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) in the vicinity of a grain storage facility formerly operated by the CCC/USDA at Centralia, Kansas. The sampling at Centralia is being performed on behalf of the CCC/USDA by Argonne National Laboratory, in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE). The objective is to monitor levels of carbon tetrachloride contamination identified in the groundwater at Centralia (Argonne 2003, 2004, 2005a). Under the KDHE-approved monitoring plan (Argonne 2005b), the groundwater is being sampled twice yearly (for a recommended period of two years) for analyses for volatile organic compounds (VOCs), as well as measurement of selected geochemical parameters to aid in the evaluation of possible natural contaminant degradation (reductive dechlorination) processes in the subsurface environment. The sampling is presently conducted in a network of 10 monitoring wells and 6 piezometers (Figure 1.1), at locations approved by the KDHE (Argonne 2006a). The results of groundwater sampling and VOCs analyses in September-October 2005, March 2006, September 2006, and March 2007 were documented previously (Argonne 2006a,b, 2007a). The results have demonstrated the presence of carbon tetrachloride …