The Powhattan USDA site (Site) is located at the northeastern edge of Powhattan in the northeast quarter of the southwest quarter of Section 28, Township 3 South, Range 16 East, in Brown County, Kansas.
The Site was identified as a potential source area during 1986 statewide water supply sampling conducted by KDHE which identified low-level carbon tetrachloride (CT) contamination in PWS Number 1. The Site was used as a grain storage facility from 1949 to approximately 1966. The Site is currently occupied by Ag Partners Coop.
Several investigations were conducted between 1987 and 2005 which identified CT, ethylene dibromide (EDB), and nitrate contamination near the former CCC/USDA facility and existing Ag Partners facility with CT concentrations above Risk-based Standards Kansas (RSK) of 5 g/L; 20 out of the 30 sample locations that exceeded RSK were on or near the former Powhattan USDA location. Soil and groundwater sampling conducted by KDHE in 2005 indicated that both CCC/USDA and Ag Partners are responsible for the CT contamination at the site and that Ag Partners is responsible for the EDB and nitrate contamination. The city of Powhattan was connected to the Brown County Rural Water District (RWD) Number 2 system in June 1995.