Contamination in groundwater at Canada, Kansas, was discovered in 1997, during limited private well sampling near former grain storage facilities of the Commodity Credit Corporation, U.S. Department of Agriculture (CCC/USDA). Subsequent investigations by the Kansas Department of Health and Environment (KDHE) confirmed carbon tetrachloride and nitrate concentrations in groundwater above the respective maximum contaminant levels (MCLs) of 5.0 {micro}g/L and 10.0 mg/L. The KDHE investigations identified both the former CCC/USDA grain storage facility and a private grain storage facility as likely sources for the carbon tetrachloride contamination. The CCC/USDA funded extension of a rural water district line to provide a permanent alternate water supply, and the KDHE has conducted long-term monitoring under the State Water Plan. This document presents an analysis of the available information for the Canada site, acquired in previous investigations and the long-term KDHE monitoring. This analysis forms the technical justification for a request to reclassify the former CCC/USDA grain storage facility at Canada as a site requiring no further action under the Intergovernmental Agreement (IGA) between the KDHE and the USDA's Farm Service Agency. The KDHE's long-term water level monitoring results indicate a consistent groundwater flow direction to the east-southeast. Consequently, the wells with the highest …

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) began its environmental investigations at Everest, Kansas, in 2000. The work at Everest is implemented on behalf of the CCC/USDA by Argonne National Laboratory, under the oversight of the Kansas Department of Health and Environment (KDHE). The results of the environmental investigations have been reported in detail (Argonne 2001, 2003, 2006a,b). The lateral extent of the carbon tetrachloride in groundwater over the years of investigation has been interpreted as shown in Figure 1.1 (2001-2002 data), Figure 1.2 (2006 data), Figure 1.3 (2008 data), and Figure 1.4 (2009 data). The pattern of groundwater flow and inferred contaminant migration has consistently been to the north-northwest from the former CCC/USDA facility toward the Nigh property, and then west-southwest from the Nigh property (e.g., Figure 1.5 [2008 data] and Figure 1.6 [2009 data]). Both the monitoring data for carbon tetrachloride and the low groundwater flow rates estimated for the Everest aquifer unit (Argonne 2003, 2006a,b, 2008) indicate slow contaminant migration. On the basis of the accumulated findings, in March 2009 the CCC/USDA developed a plan for annual monitoring of the groundwater and surface water. This current monitoring plan (Appendix A in the report …