The Cokers site consists of two closed former landfills known as Cokers Landfill Number 1 and Cokers Landfill Number 2. The closed landfills are 10 and 15 acres in size, respectively, and are located 1.3 miles northwest of Cheswold, Delaware. Landfill Number 1 was operated by Cokers Sanitation from 1962 to 1976 and was a repository for latex rubber production wastes. Landfill Number 2 was operated by Cokers Sanitation from 1977 to 1980 and was a repository for dewatered latex sludge. Contaminants found in leachates associated with the site included acrolein, and ethylbenzene (Landfill Number 2), Bis-2-chloroethyl ether (Landfill Number 1), and zinc (both sites). The potential for contaminants to migrate off-site to the Willis Branch, a tributary to the Leipsic River was identified. The Leipsic River discharges into the Delaware Bay at Bombay Hook National Wildlife Refuge approximately 11 miles downstream from the mouth of the Willis Branch.

During the remediation, a total of three acres of wetland on site were destroyed. These wetlands provided valuable habitat for waterfowl and other wildlife as well as important buffering functions for the Leipsic River watershed. The cap constructed to encapsulate landfill wastes eliminated the option of restoring wetlands on site. The Department chose public lands near the Superfund site to perform the necessary restoration activities. The proposed action will restore or replace the equivalent of the destroyed wetland services in the Leipsic River drainage by providing for improved water quality and hydrologic processes of wetlands and for improved fish and wildlife values in the drainage.