Mark Sanborn, Administrator for EPA New England (Region 1) | Official Website
The U.S. Environmental Protection Agency (EPA) has announced a cleanup plan for the initial mile of the Lower Neponset River Superfund Site, located in Boston and Milton, Massachusetts. This area stretches from where the Neponset River meets Mother Brook near Dana Avenue Bridge to the Tileston and Hollingsworth Dam.
"This represents another great milestone for the Lower Neponset River Superfund Site and is a reflection of this administration's priorities to move cleanup activities along swiftly, efficiently and fulfill the agency's core mission of protecting human health and the environment," said Mark Sanborn, EPA New England Regional Administrator.
In June 2025, an Engineering Evaluation/Cost Analysis (EE/CA) was completed by the EPA. This analysis assessed various cleanup alternatives and proposed a plan to address contamination from polychlorinated biphenyls (PCBs) and other hazardous substances. A public comment period took place from June 13 through August 1, 2025, which included a virtual hearing on July 9, 2025. Public feedback was considered before finalizing the cleanup strategy.
The plan involves dredging and excavating contaminated sediment and floodplain soil with PCB levels above one part per million. It also includes constructing a permanent cap in the first mile of the river to stabilize and restore the riverbed while minimizing changes in surface water elevation, providing habitats, and isolating remaining contamination in deeper sediment. Contaminated materials will be transported off-site for disposal, and the Tileston and Hollingsworth Dam will be removed.
Cleanup design is set to begin in 2026 with construction expected to start in 2027. The removal action is projected to take around four years to complete. More details can be found in the Action Memorandum available at https://semspub.epa.gov/src/document/01/697312 (pdf).
The Lower Neponset River Superfund Site was added to the National Priorities List on March 16, 2022. The site spans a 3.7-mile section of the Neponset River starting where it merges with Mother Brook upstream of Dana Avenue in Hyde Park, extending through Boston neighborhoods such as Hyde Park, Mattapan, Dorchester, as well as Milton, ending at Walter Baker Chocolate Dam upstream of Adams Street.
Industrialization began early in this region during the 1630s. Known as one of America's earliest industrialized watersheds, it has faced significant contamination from both point sources like factory discharges directly into rivers and non-point sources over time.
For more information about EPA's efforts at this site: https://www.epa.gov/neponsetriver
Information from this article can be found here.
