This Work Plan outlines the scope of work to be conducted to investigate the subsurface contaminant conditions at the property formerly leased by the Commodity Credit Corporation (CCC) in Powhattan, Kansas (Figure 1.1). Data obtained during this event will be used to (1) evaluate potential contaminant source areas on the property; (2) determine the vertical and horizontal extent of potential contamination; and (3) provide recommendations for future action, with the ultimate goal of assigning this site No Further Action status. The planned investigation includes groundwater monitoring requested by the Kansas Department of Health and Environment (KDHE), in accordance with Section V of the Intergovernmental Agreement between the KDHE and the Farm Service Agency of the U.S. Department of Agriculture (USDA). The work is being performed on behalf of the CCC/USDA by the Environmental Science Division of Argonne National Laboratory. A nonprofit, multidisciplinary research center operated by the University of Chicago for the U.S. Department of Energy, Argonne provides technical assistance to the CCC/USDA with environmental site characterization and remediation at former CCC/USDA grain storage facilities. Argonne issued a Master Work Plan (Argonne 2002) that has been approved by the KDHE. The Master Work Plan describes the general scope of all …

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) formerly operated a grain storage facility (during most of the interval 1949-1974) at Barnes, Kansas. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to investigate this contamination. In November 2007, the CCC/USDA began quarterly groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, in accord with the recommendations made in the report for the 2006-2007 targeted investigation (Argonne 2007). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. The sampling is presently conducted in a network of 28 individual monitoring wells at 19 distinct locations, 2 public water supply wells, and 1 private well (Figure 1.1). The results of the 2006-2007 targeted investigation demonstrated the presence of carbon tetrachloride contamination at levels slightly exceeding the Kansas Department of Health and Environment (KDHE) Tier 2 risk-based screening level of 5.0 {micro}g/L for this compound, in a plume that appears to extend from the former CCC/USDA property northwestward, toward the Barnes public …

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at Barnes, Kansas, during most of the interval 1949-1974. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to characterize this contamination. Those results were reported previously (Argonne 2008a). In November 2007, the CCC/USDA began quarterly groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, in accord with the recommendations made in the report for the 2006-2007 targeted investigation (Argonne 2008a). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. The sampling is presently conducted in a network of 28 individual monitoring wells (at 19 distinct locations), 2 public water supply wells, and 1 private well (Figure 1.1). The results of the 2006-2007 targeted investigation and the subsequent monitoring events in November 2007 (Argonne 2008b), March 2008 (Argonne 2008c), and July 2008 (Argonne 2008d) demonstrated the presence of carbon tetrachloride contamination in groundwater at levels exceeding the Kansas Department of Health and Environment (KDHE) Tier 2 …

On September 7, 2005, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) presented a Scoping Memo (Argonne 2005) for preliminary consideration by the Kansas Department of Health and Environment (KDHE). This document suggested possible remedial options for the carbon tetrachloride contamination in groundwater at Everest, Kansas. The suggested approaches were discussed by representatives of the KDHE, the CCC/USDA, and Argonne at the KDHE office in Topeka on September 8-9, 2005, along with other technical and logistic issues related to the Everest site. In response to these discussions, the KDHE recommended (KDHE 2005) evaluation of several remedial processes, either alone or in combination, as part of a Corrective Action Study (CAS) for Everest. The primary remedial processes suggested by the KDHE included the following: (1) Hydraulic control by groundwater extraction with aboveground treatment; (2) Air sparging-soil vapor extraction (SVE) in large-diameter boreholes; and (3) Phytoremediation. As a further outcome of the 2005 meeting and as a precursor to the proposed CAS, the CCC/USDA completed the following supplemental investigations at Everest to address several specific technical concerns discussed with the KDHE: (1) Construction of interpretive cross sections at strategic locations selected by the KDHE along the main plume migration …

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 a KDHE-approved monitoring plan (Argonne 2005b), the groundwater was 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 in September 2007 represented the fifth and final monitoring event performed under the two-year twice yearly monitoring program (Argonne 2006a,b, 2007a, 2008a). The results from the two-year monitoring program demonstrated the presence of carbon tetrachloride contamination at levels exceeding the KDHE Tier 2 Risk-Based Screening Level of 5 {micro}g/L for this compound in a broad groundwater plume …