The Winthrop Landfill consists of two contiguous parcels of 11 acres, with approximately 9.5 acres located along the western shore of Annabessacook Lake in the town of Winthrop, Maine. The site was initially used in the 1920s as a sand and gravel pit. In the 1930s, parts of the site became the Winthrop Town Dump, accepting mixed municipal, commercial, and industrial wastes. The site received hazardous substances between the early 1950s and mid-1970s. It is estimated that more than 3 million gallons of chemical wastes, mostly complex organic compounds including resins, plasticizers, solvents, and other process chemicals, were disposed at the site. Wastes were openly burned until 1972, and landfilling occurred from 1972 until 1982. The selected remedial action for this site includes; the extension of an alternate water supply to residences in close proximity to the landfill; construction of a chain link fence around the landfill, and imposition of deed restrictions prohibiting use of the landfill for activities other than the remedial action; prohibition of ground water withdrawals for purposes other than remedial action; prohibition of excavation in the landfill, except for residential construction or remedial action; quarterly sampling of monitoring points in sensitive areas; grading and placement of a RCRA cap over the entire landfill; completion of engineering design work (geologic, hydrogeologic, and treatability pilot studies); and establishment of an alternate concentration limit (acl) for each contaminant in the ground water based on RCRA Section 264.94(b) criteria.