December 2023 Update: Residual Designation Activities Underway for the Charles River, Neponset River, and Mystic River Watersheds

Issuance of Draft RDA Permit

EPA continues its work on the technical analysis to support its decision-making and the administrative record for the development of the Residual Designation (RD) Permit in the Charles, Mystic, and Neponset watersheds. EPA is on track to issue the draft permit(s) by September 2024 and plans to update its website with additional supporting technical documents in early 2024.

Stakeholder Outreach

EPA, in partnership with the Consensus Building Institute, will be conducting outreach and informational sessions with interested stakeholders in the three affected watersheds beginning in early 2024. We will also be posting updates on the outcome of these stakeholder outreach sessions and providing opportunities for additional involvement by interested parties.

Technical Assistance and Tools

On October 19, 2023, Region 1 announced that it will be working with several MA communities, including Somerville, (Mystic River Watershed), Milford (Charles River Watershed) and Stoughton (Neponset River Watershed)in 2024 to discuss challenges and solutions for effective nutrient management through retrofits for targeted stormwater management in communities with environmental justice concerns. This work is supported by Charles, Mystic, and Neponset River Watershed Associations, the University of New Hampshire Stormwater Center, and the Consensus Building Institute. The effort will be particularly focused on low-cost green infrastructure options that align local needs with the municipalities' maintenance capabilities and provide additional benefits to communities with environmental justice concerns. It is expected that the lessons from these case studies will be shareable and benefit other municipalities and RDA permit holders in the Charles, Mystic, and Neponset River watersheds.

EPA plans to post on its website in early 2024 two additional technical assistance resources: an Impervious Cover Data Dashboard for each watershed that will allow users to see pollutant loading from the different types of land use categories. EPA is also finalizing municipal-specific technical information sheets that provide municipalities with some background on the RDA permitting process and highlight the specific types of parcels and associated pollutant loads that may be subject to RDA permitting within their town boundaries.

Related Permitting Actions

EPA continues to work on the permit renewal for the 2016 Massachusetts Small MS4 General permit that expired in 2022. EPA currently plans to release a draft permit for public comment in 2024 prior to the release of the RDA draft permit.