The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), formerly operated grain storage facilities at two different locations at Everest, Kansas (Figure 1.1). One facility (referred to in this report as the Everest facility) was at the western edge of the city. The second facility (referred to in this report as Everest East) was about 0.5 mi northeast of the town. The CCC/USDA operated these facilities from the early 1950s until the early 1970s, at a time when commercial fumigants containing carbon tetrachloride were in common use by the CCC/USDA and private industry for the preservation of grain in storage. In 1997 the Kansas Department of Health and Environment (KDHE) sampled several domestic drinking water and non-drinking water wells in the Everest area as part of the CCC/USDA Private Well Sampling Program. All of the sampled wells were outside the Everest city limits. Carbon tetrachloride contamination was identified at a single domestic drinking water well (the Nigh well, DW06; Figure 1.1) approximately 3/8 mi northwest of the former Everest CCC/USDA grain storage facility. Subsequent KDHE investigations suggested that the contamination in DW06 could be linked to the former use of grain fumigants at the CCC/USDA …

On September 8-9, 2005, representatives of the Kansas Department of Health and Environment (KDHE), the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA), and Argonne National Laboratory met at the KDHE's offices in Topeka to review the status of the CCC/USDA's environmental activities in Kansas. As a result of this meeting, the KDHE recommended several additional activities to augment the CCC/USDA's investigations at Everest, Kansas, and assist in the selection of remedial approaches to be evaluated as part of a Corrective Action Study (CAS) for this site. The requested actions included the following: (1) Construction of several additional interpretive cross sections illustrating the hydrogeologic setting along the apparent main plume migration pathway to the north-northwest of the former CCC/USDA facility, as well as in the vicinity of the Nigh property. (2) Installation of additional permanent monitoring wells, to better constrain the apparent western, northern, and northwestern margins of the existing groundwater plume. (3) Development of technical recommendations for a phased pumping study of the Everest aquifer unit in the area near and to the north of the Nigh property.

On September 8-9, 2005, representatives of the Kansas Department of Health and Environment (KDHE), the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA), and Argonne National Laboratory met at the KDHE's offices in Topeka to review the status of the CCC/USDA's environmental activities in Kansas. A key CCC/USDA goal for this meeting was to obtain KDHE input on the selection of possible remedial approaches to be examined as part of the Corrective Action Study (CAS) for this site. As a result of the September meeting, the KDHE recommended several additional activities for the Everest site, to further assist in selecting and evaluating remedial alternatives for the CAS. The requested actions included the following: (1) Construction of several additional interpretive cross sections to improve the depiction of the hydrogeologic characteristics affecting groundwater and contaminant movement along the apparent main plume migration pathway to the north-northwest of the former CCC/USDA facility, and in the vicinity of the Nigh property. (2) Identification of potential locations for several additional monitoring wells, to better constrain the apparent western and northwestern margins of the existing groundwater plume. (3) Development of technical recommendations for a stepwise pumping study of the Everest aquifer unit in the …