The U.S. Environmental Protection Agency announced on April 23 that it is proposing targeted modifications to the 2016 Small Municipal Separate Storm Sewer System (MS4) general permit for Massachusetts communities.

An EPA statement said that the proposed modifications would give municipalities more tools and flexibility for permit implementation while also ensuring that the water quality goals of the Clean Water Act are met.

The proposed modifications were developed through a multi-year mediation between the EPA and parties who challenged the underlying 2016 permit.

Last December, the EPA announced that a settlement agreement had been reached between the agency and the permit litigants – including municipalities, environmental groups and other stakeholders – and initiated a public comment period. The settlement agreement was executed in mid-April. According to the EPA, the proposed modifications to the permit are identical to those contained in the settlement.

The EPA will hold two informational webinars on the proposed permit modifications, with the first set for May 4. To register and for more information, visit

The EPA will accept public comments on the proposed permit modifications for 45 days from the announcement date.

EPA New England Regional Administrator Dennis Deziel called the modifications to the 2016 MS4 “a win-win.”

“These changes balance the implementation needs of Massachusetts communities with the water quality protections required under the Clean Water Act,” he said. “When fully implemented, the MS4 permit will continue to protect the environment and adhere to the law.

“Stormwater is the largest contributor of pollutants to impaired rivers, lakes, streams, ponds and other waters in Massachusetts. The MS4 permit is an important step to reduce the harmful impact of polluted stormwater on local water bodies.”

The EPA’s New England Regional Office issues Clean Water Act National Pollutant Discharge Elimination System permits in Massachusetts and New Hampshire. MS4 permits are NPDES permits that authorize certain discharges of municipal stormwater to surface waters.

After the EPA finalized the Massachusetts Small MS4 General Permit, parties filed petitions for review, including the National Association of Homebuilders, the Home Builders and Remodelers Association of Massachusetts Inc., the Center for Regulatory Reasonableness, the Massachusetts Coalition for Water Resources Stewardship, the town of Franklin, the city of Lowell, the Conservation Law Foundation, and the Charles River Watershed Association. These petitions were consolidated with a challenge to the EPA’s 2017 New Hampshire Small MS4 General Permit in the U.S. Court of Appeals for the District of Columbia Circuit. Once consolidated, the cases were entered into the DC Circuit’s mediation program. After more than two years of discussions, the parties negotiated a proposed settlement agreement, which was announced on Dec. 27, 2019, issued for public comment, and executed by all parties on April 15.

The Federal Register notice, proposed MS4 permit modifications, statements of basis that explain the EPA’s rationale for the proposed modifications, and instructions on how to formally submit comments on the proposed permit modifications are available on under the docket number EPA-R01-OW-2020-0216.