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.
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
New MS4 General Permit Issued
The new, modified MS4 General Permit is available immediately below followed by 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.
- Powerpoint Presentation from Informational Hearing on September 10, 2015
- Notice of Informational Hearing on September 10, 2015
- Revised Draft MS4 Permit July 7, 2014 to August 27, 2015 Comparison Markup
- Revised Draft MS4 Permit August 27, 2015 “Clean” Copy
- Revised Draft MS4 Permit August 27, 2015 Summary of Significant Changes
- Revised Draft MS4 Permit July 7, 2014 to January 26, 2015 Comparison Markup
- Summary of Modifications to MS4 General Permit, January 26, 2015
- Comparison Chart Between Proposed CT-MS4, Modified CT-MS4 and EPA/MA-MS4
- December 23, 2014 DEEP Press Release
- Notice of December 17, 2014 Hearing
- Comments Received Following the July 7, 2014 Notice of Tentative Determination to Renew with Modifications the MS4 General Permit
- August 6, 2014 Proposed MS4 Reissuance Informational Meeting PowerPoint
- Fact Sheet for the Proposed MS4 General Permit
- July 8, 2014 Draft General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems
- July 7, 2014 Public Notice of Tentative Determination of the Intent to Renew with Modifications the 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.
Content Last Updated February, 2017