Saco Tannery Waste Pits

Overview

From 1959 to 1981, more than 23 million gallons of industrial waste were dumped into two lagoons and 53 pits at this 212-acre site about four miles north of a tannery in Saco, Maine. Wastes included chromium sludges, acid wastes, methylene chloride, and caustic substances. EPA added the site to the National Priorities List (NPL) in September 1983.

Nine contaminants have been identified as posing unacceptable risk here. They are antimony, arsenic, bis(2-ethylhexyl)phthalate, chlorobenzene, chromium, chromium compounds, lead, and manganese. These have been found in soil, groundwater, surface water, sediment, and sludge across the entire site. Before cleanup, people who came into direct contact with contaminated groundwater, soil, or sediment faced potential health risks, and wildlife and wetlands at the site were also at risk.

Active cleanup ran from the early 1980s through the early 1990s. A Record of Decision selecting the cleanup approach was issued in September 1989. Between 1992 and 1993, workers installed soil cover systems over all disposal areas, revegetated the site, put up permanent security fencing, and created on-site wetlands. Because enough wetland acreage could not be replaced on-site, EPA and the Maine Department of Environmental Protection purchased 247 acres of the Saco Heath, a threatened habitat in the same watershed, as compensatory mitigation. Construction finished in September 1993, and EPA deleted the site from the NPL in September 1999. The site was certified as ready for anticipated reuse in June 2006.

Human exposure and groundwater migration are currently assessed as under control. However, the 2024 Five-Year Review, completed in July 2024, could not confirm the cleanup remains fully protective because PFAS was detected in on-site and nearby residential wells. PFAS stands for per- and polyfluoroalkyl substances, a group of man-made chemicals. A new Remedial Investigation that began in July 2024 is looking at whether PFAS is moving off-site and at arsenic background conditions. A follow-up Feasibility Study is estimated to start between September and November 2026. The next Five-Year Review is scheduled for 2029. Institutional controls remain in place to restrict incompatible land uses. The State of Maine handles ongoing operations and maintenance.

Community members who want to learn more or ask questions can contact EPA's Community Involvement Coordinator or the Remedial Project Manager. Site records are available at Saco City Hall, the Deyer Library in Saco, and the EPA Region 1 office in Boston.