Lower Neponset River Declared a Superfund Site

Today, Mayor Michelle Wu joined EPA Regional Administrator David Cash and members of the Massachusetts Delegation to declare the Lower Neponset River as a part of the U.S. Environmental Protection Agency’s Superfund National Priorities List (NPL). The Lower Neponset River site is identified as the 3.7-mile stretch of the Neponset River from the point where it merges with Mother Brook in Hyde Park, extending downstream to the Walter Baker Dam in Dorchester and into the town of Milton, Mass. This declaration will support the City of Boston in transforming the river into an ecologically sound, healthy, and sustainable natural space while supporting a thriving local community. 

“Having been part of neighborhood meetings about this area and Neponset River cleanup efforts over the years, I know how much this natural treasure means to our communities. This designation will open up full federal partnership to invest the resources in restoring a healthy ecosystem that is especially needed in our work to become a Green New Deal city,” said Mayor Michelle Wu. “For far too long, environmental justice communities like Mattapan have been bearing the brunt of climate change and environmental hazards, and I look forward to working closely with the Environmental Protection Agency on improving this beautiful resource in Boston.”

“Listing the Lower Neponset River Site on the Superfund NPL is a big step for the Boston and Milton neighborhoods. We now have a mechanism to clean up the river and protect the health of the communities around it, as well as increasing the overall use and enjoyment of this important resource” said EPA Regional Administrator David W. Cash. “We have to thank our local partners in the communities and the Commonwealth of Massachusetts for their support and hard work to get the site listed, and we look forward to continued partnership as we embark on the next phase of the project. This is a win for families who value recreating on the river, a win for great blue herons, a win for fish, and a win for Massachusetts.”

Historically, numerous mills were established along this portion of the Neponset River in the neighborhoods of Dorchester, Hyde Park, Mattapan, and the town of Milton, MA. The mills initially utilized dams to generate power to turn mill grinding wheels and later to operate large industrial mills. These mills and other industrial facilities in the area are suspected to have contaminated this portion of the Neponset. Based on preliminary studies, this portion of the river contains sediment contaminated with elevated levels of polychlorinated biphenyls (PCBs), which can be detrimental for public and environmental health. 

For more than a decade, community members throughout Hyde Park, Dorchester and Mattapan have expressed concern about the potential contamination. In referring the site to EPA, the City and Commonwealth agreed that listing the river on the NPL presents the most significant opportunity to remediate the river and surrounding land. The City, in conjunction with the EPA and the Commonwealth, has a shared goal of protecting the people who have been directly impacted by the industrial contamination in the river.

"With the addition of the Lower Neponset River to the US EPA Superfund National Priorities list, our community is very excited to have the wonderful river alongside our neighborhood become a safer community resource," said Vivien Morris of the Edgewater Neighborhood Association. 

The NPL includes the nation’s most serious uncontrolled or abandoned releases of contamination. The list serves as the basis for prioritizing EPA Superfund cleanup funding and enforcement actions. EPA determined that the Lower Neponset River site qualified for the NPL because this portion of the river contains sediment contaminated with elevated levels of polychlorinated biphenyls (PCBs) that may pose a risk to human health and or the environment.

NPL designation is the first step in a series of actions to transform and remediate the Lower Neponset River. The EPA’s Superfund Process will now move to remedial investigation, which will determine the extent of the contamination and assess its risks to the local community and the ecosystem. A feasibility study must then be conducted to determine possible cleanup alternatives. A plan must then be developed and a formal public comment period will begin. A cleanup decision will then be made and remedial action will be conducted. This process will be led by the EPA.

Open spaces with healthy ecosystems function as a method to achieve our climate mitigation and adaptation goals while supporting our path to become a Green New Deal city. Mayor Wu’s Administration is committed to environmental protection and is laying the foundation to become a carbon neutral city. Within her first one hundred days in office, Mayor Wu signed an ordinance to divest City-funds from the fossil fuel, tobacco, and private prison industries. Mayor Wu also announced new, lower community choice electricity rates and outlined steps to reduce vehicle emissions and electrify the City fleet. Mayor Wu additionally announced the launch of the two-year fare-free program on MBTA bus Routes 23, 28, and 29 on March 1, 2022.