EPA Issues Explanation of Significant Differences for the Charles George Reclamation Trust Landfill Superfund Site
BOSTON, Mass. (Oct. 7, 2025) – U.S. Environmental Protection Agency (EPA) has finalized the Explanation of Significant Difference (ESD) for the Charles George Reclamation Trust Landfill Superfund Site in Tyngsborough, Massachusetts.
The ESD makes changes to the 1988 Record of Decision (ROD) that addressed contaminated groundwater migration, permanent treatment of landfill gas using an enclosed flare, excavation of contaminated sediments in Dunstable Brook, and leachate and groundwater treatment.
The selection of a different, documented remedial alternative represents a significant change to the Selected Remedy, as specified in the ROD, but not a fundamental change regarding scope, performance, or cost.
These changes will modernize the current outdated system, ensure that contaminated groundwater will be better captured rather than continuing to migrate under and around the current collection system and also ensure that the treatment system can address emerging contaminants since the current system was not designed to treat these.
Changes include the addition of site-specific contaminants of concern and cleanup levels in groundwater, modification of remedial action objectives to account for new contaminants of concern, as well as improvement of the on-site groundwater collection system and expansion of the existing groundwater collection system, and on-site groundwater treatment and discharge to on-site surface water instead of through the Tyngsborough sewer to the Lowell wastewater treatment systems.
Copies of the ESD, Administrative Record, and other background information about the Site can be found at www.epa.gov/superfund/charlesgeorge.