The Ellisville Area site is a former waste oil disposal site in Ellisville, St. Louis County, Missouri. The site consists of the 11.6-acre Bliss property and four contiguous properties where hazardous substances have been identified. Land use in the area is mixed residential, rural, and recreational. Surface runoff at the site drains to Caulks Creek, a tributary of Bonhomme Creek, which enters the Missouri River about 1 mile upstream of a city of St. Louis waterworks intake. During the 1960's and 1970's, Bliss Waste Oil Company used the site to transport and dispose of waste oil products (some of which were contaminated with dioxin), industrial wastes, and chemical wastes. Dioxin-contaminated waste oil was applied directly to surface soil for dust control, and spillage from trucks also occurred. Investigations conducted from 1982 through 1983 concluded that site contamination was not affecting the ground water; however, some onsite surface migration of contaminated soil and sediment had occurred. The ROD provides a final remedy for dioxin-contaminated soil, which involves excavation and direct transport of dioxin wastes offsite for treatment. The 1986 remedy for non-dioxin wastes is not affected. The primary contaminant of concern affecting the soil is dioxin, an organic. The selected remedial action for the site includes excavating and direct transportation of approximately 7,000 cubic yards of dioxin-contaminated soil for treatment at an offsite temporary thermal treatment unit constructed at the Times Beach site; disposing of treatment residuals at the Times Beach site as nonhazardous solid waste if delisting criteria are met, or retreating at Times Beach or managing residuals offsite as a hazardous waste if delisting criteria are not met.