2025 Updates: Residual Designation Authority (RDA) Activities Underway for the Charles, Neponset, and Mystic River Watersheds
April 2025
All Public Comments have been posted to Regulations.gov
Following the close of the public comment period for the Preliminary Designation of certain stormwater discharges from commercial, industrial, and institutional properties with one acre or more of impervious surface in the Charles, Neponset, and Mystic River watersheds in Massachusetts for regulation under the Clean Water Act's ("CWA") National Pollutant Discharge Elimination System ("NPDES") permitting program and draft NPDES General Permit for Private Commercial Industrial, and Institutional Stormwater Discharges in the Charles, Mystic, and Neponset, EPA has posted all public comments received within the comment period to regulations.gov. The comments can be viewed at https://www.regulations.gov/docket/EPA-R01-OW-2024-0492/comments
March 2025
Public Comment Period on Draft CII General Permit and Preliminary RDA Determination has closed
The public comment period for the Preliminary Designation of certain stormwater discharges from commercial, industrial, and institutional properties with one acre or more of impervious surface in the Charles, Neponset, and Mystic River watersheds in Massachusetts for regulation under the Clean Water Act's ("CWA") National Pollutant Discharge Elimination System ("NPDES") permitting program and draft NPDES General Permit for Private Commercial Industrial, and Institutional Stormwater Discharges in the Charles, Mystic, and Neponset River Watersheds in Massachusetts ("Draft CII GP") has closed.
The original public comment period ran from October 31, 2024 to January 29, 2025. In response to stakeholder requests, the public comment period end date was extended by 45 days from January 29, 2025 to March 17, 2025.
January 2025
Public Comment Period on Draft CII General Permit and Preliminary RDA Determination
EPA continues to accept public comments on the Draft CII General Permit and Preliminary RDA Determination. Comments can be submitted using the following methods:
- Federal eRulemaking Portal: https://www.regulations.gov/docket/EPA-R01-OW-2024-0492 (our preferred method). Follow the online instructions for submitting comments.
- Email: R1.RDA@epa.gov, and include "Comments on the Preliminary Designation and/or Draft CII GP" in the subject line.
- Mail: U.S. EPA Region 1, Water Division, Attn: Laura Schifman, 5 Post Office Square, Suite 100, Mail Code 06-4, Boston, Massachusetts 02109-3912. If comments are submitted in hard copy form, please also email a copy to R1.RDA@epa.gov.
The comment period has been extended from January 29, 2025 to March 17, 2025.
EPA hosted a virtual Public Meeting on January 7th 2025. The video recording with closed captions is available. EPA has published a Spanish translation of closed captions that is available now.
Recording of the January 7, 2025 Public Meeting
EPA hosted two Public Hearings on January 22nd and January 23rd at 7 PM EST.
RDA Parcel-Level Interactive Map
EPA has published its RDA Parcel-Level Interactive Map for the Charles, Mystic and Neponset River Watersheds. The RDA Parcel-Level Interactive Map is intended to give owners of certain private properties that may become subject to the General Permit for Private Commercial, Industrial, and Institutional Stormwater Discharges in the Charles, Mystic, and Neponset River watersheds in Massachusetts ("CII GP"), currently in draft form, some preliminary information about the amount of impervious cover ("IC") on their private properties. The map is accessible at https://www.epa.gov/npdes-permits/residual-designation-charles-river-watershed-mystic-river-watershed-and-neponset#ParcelLevelInteractiveMap and at Residual Designation Authority (RDA) Parcel-Level Interactive Mapping Tool.