Revised Permits for Small Municipal Stormwater Systems – Coming Soon to Massachusetts; New Hampshire Next in Line, with Maine Not Far Behind

Environmental Alert


The U.S. Environmental Protection Agency (EPA), Region 1, recently announced that in the next few weeks it will finalize a revised general permit for small municipal stormwater sewer systems (“MS4s”) in Massachusetts. Under the Clean Water Act (“CWA”), MS4 communities must reduce pollutants discharged via stormwater to the “maximum extent practicable” and take other water quality protection measures.

The new permit, which will cover 260 Massachusetts municipalities, is to replace a 2003 EPA MS4 permit that has been administratively continued since it expired in 2008 (the CWA programs have never been delegated by EPA to Massachusetts). In 2010, EPA released for public comment (but never finalized) two separate draft MS4 permits one for operators located in the North Coastal watershed and the other for those located in the Interstate, Merrimack and South Coastal watersheds. The current draft permit, released in September 2014, takes a more uniform state-wide approach. Region 1 has received extensive public comment, much of it critical, regarding the permit’s requirements, which are far more extensive than those of the 2003 permit. These include:

  • Costly sampling and analysis of stormwater during wet weather events;
  • Treatment or retention of the first inch of precipitation from all impervious surfaces for new development or redevelopment projects;
  • Pollution reduction and other varying requirements for communities discharging to impaired waters; and
  • Preparation of numerous detailed plans and assessments to be completed within the first permit year – operations and maintenance plans, pollutant source identification plans, stormwater pollution prevention plans, and inventories and conditions assessments of system outfalls.

New Hampshire

As in Massachusetts, EPA is the stormwater permitting authority for New Hampshire. New Hampshire MS4 communities are subject to a 2003 MS4 permit that also has been administratively continued. After releasing but never finalizing a revised draft MS4 permit in 2008, Region 1 released a new draft permit for a public comment period that ended on August 15, 2013 (after two extensions). EPA reopened the comment period for select sections of the 2013 draft New Hampshire small MS4 permit, based on comments received and changes to New Hampshire state water quality standards. That comment period expired on November 20, 2015, but no final permit decision has been announced by EPA. Like the Massachusetts draft MS4 permit, the draft New Hampshire permit includes stepped-up requirements and has received substantial critical comment from the affected municipalities.


The Maine Department of Environmental Protection (MEDEP) is the CWA stormwater permitting authority for the State of Maine (i.e., it is a “delegated” program). MEDEP issued its most recent MS4 permit on July 1, 2013. That permit is scheduled to expire five years from the date of issuance (July 1, 2018). However, the state permit is subject to the review and approval of EPA. Therefore, it is anticipated that the next version of the Maine MS4 permit will resemble the Massachusetts and New Hampshire permits, with greatly increased requirements relative to the current permit.