Winthrop Landfill covers 13 acres in Winthrop, Maine, and includes both the municipal Winthrop Town Landfill and the privately owned Savage Landfill. From the 1930s through the mid-1970s, the site took in municipal, commercial, and industrial waste, including an estimated 3 million gallons of chemical waste such as resins, plasticizers, and solvents. Rusting and leaking barrels were discovered in 1979, prompting the town to close the landfill. The site was added to the National Priorities List in 1982 and 1983, depending on the source document.
Twelve contaminants of concern have been identified at the site, spread across groundwater, soil, and sediment. These include arsenic, toluene, acetone, tetrahydrofuran, and two ketones, 2-butanone and 4-methyl-2-pentanone. Contaminated groundwater was identified as the primary threat to human health in a 1985 EPA Record of Decision (ROD). A groundwater extraction and treatment system ran from March 1995 to November 2002 and met cleanup standards for all contaminants except arsenic. Arsenic exceedances are now being managed through natural attenuation and ongoing monitoring. A ROD Amendment issued in September 2019 added a cover system to address arsenic exposure in sediment, along with surface water and sediment monitoring.
Physical cleanup construction was completed on December 23, 1997. A landfill cap was finished in 1987 and remains stable, with an intact perimeter fence. The public water system has been extended to residents near the site, and a town ordinance prohibits groundwater use in the area. Human exposure is under control, and groundwater migration is stabilized with no unacceptable discharge to surface water. The site achieved sitewide readiness for anticipated reuse on September 30, 2021. Institutional controls, including zoning restrictions and excavation prohibitions, remain in effect and will stay in place as long as contamination and cleanup components are present.
EPA completed its seventh Five Year Review on August 19, 2022. The next review is estimated between August and October 2027. Two additional operable units related to groundwater have been identified but do not yet have formal cleanup decisions. The site has not been deleted from the National Priorities List.
Community members with questions can contact the EPA's Community Involvement Coordinator or the Remedial Project Manager. Public records are also available at the Winthrop Town Offices and the EPA Region 1 records center in Boston.
