EPA announces public hearing for updated draft of MS4 general permit in Massachusetts
The U.S. Environmental Protection Agency (EPA) announced a newly scheduled public hearing for an updated draft of the general permit for all small and regulated "Municipal Separate Storm Sewer Systems" (MS4s) located in Massachusetts. The draft permit was initially place on public notice in November 2024. This affects more than 260 municipalities in the Commonwealth, all of which were already covered under the previous Massachusetts Small MS4 General Permit that EPA issued in 2016.
The updated draft of this existing general permit continues to require MS4s to develop, implement, and enforce a "Stormwater Management Program" designed to control the discharge of pollutants from stormwater to water bodies to the maximum extent practicable, protect water quality, and satisfy appropriate requirements of the federal Clean Water Act.
EPA encourages and will accept written comments from the public on the Draft Permit during the notice period which ends May 21, 2025. The Draft Permit and associated documents are available here.
In addition, EPA will hold a virtual hearing for the Draft Permit on May 7, 2025, at 7pm. The registration for the virtual public hearing can be found here.
Rainwater that falls on hard surfaces such as parking lots, roadways, and roofs can pick up pollutants that are then carried into local waterways via the storm drains, pipes, and ditches that make up municipal storm sewer systems. Stormwater runoff flows over these hard surfaces directly into storm drains so there is no opportunity for soil and plants to absorb the rainwater and filter out pollutants.
Pollutants lead to water quality issues (such as growth of harmful algae and bacteria and accumulation of trash, oil and grease, and metals) that can make waters unsafe for swimming and boating and can harm aquatic life.
The requirements in the Draft Permit largely follow or build on the requirements of the currently effective 2016 MA MS4 Permit. It also includes new requirements to expand public engagement, develop street design standards that feature nature-based solutions, develop an integrated system to track MS4 assets and maintenance, begin implementing plans developed under the 2016 Permit to install controls to treat stormwater runoff on permittee-owned property, and begin upgrading catch basins to better control solids in stormwater runoff.
The Draft Permit requires municipal permittees that discharge to nutrient-impaired waterbodies to begin installing stormwater treatment based on the Source Identification Reports developed under the 2016 Permit. Finally, the Draft Permit proposes a new requirement for permittees discharging to waterbodies in the Mystic River watershed to reduce the phosphorus load in stormwater discharges from hard surfaces by 20% within six years.
