The Libby Ground Water Contamination site (also known as the Champion Mill site or the Libby Pesticide site) is located on the Champion International Corporation lumber and plywood mill in the City of Libby, Lincoln County, Montana. The contaminated soil/source area is within the confines of the facility; however, ground water contamination extends well into the City of Libby. Wood treating fluids and their constituents, including creosote and PCP, are the contaminants of concern at the site. They are found in soil and sediments at several different locations, including former waste pits, tank storage areas, and butt dip and treatment sites. The contamination is the result of spent fluids, overflow of treatment tanks, and spills. In addition to creosote and PCP, certain carrier fuels or oils were used at the site and contributed VOC contaminants. The site has been divided into three operable units; however, they require concurrent remediation. The primary contaminants of concern affecting the soil, sediments, and ground water at the site are VOCs including benzene; other organics including dioxin, PAHs (creosote constituents), and PCP; metals including arsenic; and oil.