EPA Announces Superfund Cleanup Plan for Lower Neponset River
On November 10th, 2025, the U.S. Environmental Protection Agency (EPA) released its Phase I Action memorandum, which contains general information on its proposed cleanup method for the first mile of the Superfund Site, which spans from where Mother Brook connects to the Neponset River to the Tileston and Hollingsworth (T&H) Dam.
The release of this document and what it contains is a huge win for the Neponset, as EPA plans to conduct a robust cleanup that will remove at least the top three feet of contaminated sediment in the river bottom and contamination along the riverbanks within this first mile, including the removal of the dilapidated T&H dam.
Read EPA press release, Nov. 10, 2025
This milestone follows a summer focused on EPA’s Engineering Evaluation/Cost Analysis document, which gave an overview of the contamination that was found in this section of the River and listed four alternatives for how the cleanup could be conducted.
NepRWA and the EPA Community Advisory Group advocated for the fourth option to be selected, which was ultimately chosen by EPA, and conducted outreach to the public to encourage as many public comments expressing support as possible.
There were over 120 comments submitted, and EPA’s response to these comments can be found within the Action memorandum.
While EPA provides some information on how they’ll go about removing sediment, there are multiple instances where the Agency states that specific details of the remediation will be decided during the design phase of this effort, scheduled for 2026.
Want to help ensure this cleanup leads to the restored Neponset River we all want? Join the Community Advisory Group meeting next Tues. night, November 18th.
Email CAG@neponset.org for the meeting link.
NepRWA plans to be involved in this design work as much as possible and will advocate for EPA to remove all contamination where feasible, rather than installing a cap in areas where contamination may be too deep to remove. We will also advocate for restoration measures to ensure the native ecosystem can return as soon as work is completed.
Barring any setbacks, remediation work could start as early as winter 2026 or spring 2027. We look forward to this next phase of the Superfund process and plan to work alongside EPA and our state agencies to create a Neponset that is healthy for plants and wildlife, and accessible to the community.
Learn more about the Superfund project.
For any questions about the project, please email NepRWA Greenways Director, Andres Ripley, at ripley@neponset.org
