Final work plan for targeted investigation at Hilton, Kansas.

This Work Plan outlines the scope of a targeted investigation to update the status of carbon tetrachloride contamination in groundwater associated with grain storage operations at Hilton, Kansas. The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), operated a grain storage facility in Hilton during the 1950s and 1960s. At the time of the CCC/USDA operation in Hilton, grain storage facilities (CCC/USDA and private) were located along the both sides of the former Union Pacific railroad tracks (Figure 1.1). The main grain storage structures were on or near the railroad right-of-way. The proposed targeted investigation, to be conducted by Argonne National Laboratory on the behalf of CCC/USDA, will supplement Argonne's Phase I and Phase II investigations in 1996-1997. The earlier investigations erroneously focused on an area east of the railroad property where the CCC/USDA did not operate, specifically on a private grain storage facility. In addition, the investigation was limited in scope, because access to railroad property was denied (Argonne 1997a,b). The hydrogeologic system at Hilton is potentially complex