The Tri-City property, occupying approximately one-quarter acre, is located in Temple Terrace, Hillsborough County, Florida. The site is located within one-fourth mile of at least eight private drinking water wells and within two miles of major public drinking water supply wells. From 1960 to 1975 the Tri-City property was used for the operation of a heating oil service business. From 1978 to 1983 Tri-City Oil Conservationist Corporation was a waste oil collection and distribution center. During the operational period of the Tri-City site, the Hillsborough County Environmental Protection Commission and the Florida Department of Environmental Regulation (FDER) received several complaints regarding odor problems and sloppy practices. In 1982 a 3,000 gallon waste oil spill occurred at the Tri-City operation. The owner failed to clean up the site at the request of FDER and in February 1984, EPA conducted an immediate removal action. Following the removal, soil contamination posed a threat to the ground water.