The 2007 investigation of carbon tetrachloride and chloroform contamination at Powhattan, Kansas, was conducted at the request of the Kansas Department of Health and Environment (KDHE 2006a). The Environmental Science Division of Argonne National Laboratory implemented the investigation on behalf of the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). The primary purposes of the investigation were to evaluate potential contaminant source areas on the former CCC/USDA property, determine the horizontal and vertical extent of potential contamination, conduct groundwater monitoring, and provide recommendations for future action.