DEEP: Municipal Stormwater

Municipal Stormwater
The General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems (MS4 General Permit) is the product of a mandate by the U.S. Environmental Protection Agency (USEPA) as part of its Stormwater Phase II rules in 1999.  This general permit requires each municipality to take steps to keep the stormwater entering its storm sewer systems clean before that stormwater enters water bodies. One important element of this permit is the requirement that towns implement public education programs to make residents aware that stormwater pollutants emanate from many of their everyday living activities, and to inform them of steps they can take to reduce pollutants in stormwater runoff.
The current MS4 General Permit has been extended to June 30, 2017 as the modified MS4 General Permit (see below) will become effective July 1, 2017.    No re-registration is required for this extension under the current MS4 General Permit.  Permittees must continue implementing their Stormwater Management Plan, conduct annual sampling and submit their annual reports.
  • Current MS4 General Permit -- Expires June 30, 2017
  • New! 2016 Annual Report Transmittal Form (Contains annual report fee requirements. Please note that DEEP is no longer sending out invoices for the annual report review fee.) (Word) (PDF)
  • Annual Monitoring Report Form (Word) (PDF)
New MS4 General Permit Issued   
The new, modified MS4 General Permit is available below followed by the Registration Form, MS4 Town Permit Numbers, MS4 Best Management Practices, a Fact Sheet, DEEP Response to Comments, the MS4 Hearing Notice of Termination, and a marked-up version comparing the original July 8, 2014 draft MS4 General Permit and the January 20, 2016 new, modified MS4 General Permit.  All current permittees and new permittees (8 new towns plus state and federal institutions) will prepare and submit a new registration and Stormwater Management Plan by April 1, 2017. Coverage under this new MS4 permit will then become effective on July 1, 2017.
Documents below provide a history of the negotiations between stakeholders of the MS4 General Permit that included Connecticut municipalities, environmental groups and DEEP  leading to the issuance of the above-noted MS4 General Permit.
Draft DOT Separate Storm Sewer System General Permit  
Town by Town Water Quality Factsheets
The factsheets below provide a variety of water quality data in various formats for every city, town, or borough in Connecticut.
Related Information
Content Last Updated June, 2017