Stormwater Management

NEW:  Report Water Pollution Concerns here

Use the above link to report concerns related to water pollution. Submitted complaints are reviewed on an ongoing basis and will be investigated in accordance with the potential environmental harm and risk to public safety. 

If you are representing a municipality and you are reporting a bypass, use the reporting instructions found on the Bypass Reporting for Municipalities webpage.

If your complaint is an environmental emergency, call DEEP's Emergency Response Unit 24 hours a day at 866-DEP-SPIL (866-337-7745) or 860-424-3338. Please see DEEP's Reporting Environmental Concerns and Problems webpage for additional reporting guidance.

NEW: Online Noncompliance Reporting
Effective December 1, 2023, DEEP’s Water Permitting and Enforcement Division (“WPED”) is receiving noncompliance notifications and follow-up reports required under RCSA Section 22a-430 electronically using a web-based platform. The online noncompliance notification and report forms should be used by facilities with discharge permits issued by WPED to report instances of permit noncompliance including but not limited to effluent limit violations, equipment malfunctions, spills, and bypasses. These forms do not replace DEEP’s 24-hour/day Emergency Response Unit call hotline.

Submit a notification of noncompliance here.
Submit a noncompliance follow-up report here.

What is Stormwater?

Stormwater is water resulting from rain or snowmelt that runs off surfaces such as rooftops, paved streets, highways and parking lots. Along the way, the water may pick up and transport contaminants including motor oils, gasoline, antifreeze, and brake dust (commonly found on pavements), fertilizers and pesticides (found on landscaped areas), and soil sediments (from farms and construction sites). The water eventually flows into a local stream, river or lake, or into a storm drain and continues through storm pipes until it is released untreated into a local waterbody.
Stormwater results in significant pollution to surface water affecting primary contact recreation such as swimming and aquatic life use support. DEEP is working to engage stakeholders to prevent the introduction of pollutants into stormwater through its Non Point Source Pollution Management and Coastal Nonpoint Source Pollution Control Programs.


How is Stormwater Regulated?

The Environmental Protection Agency (EPA) has mandated a number of permit programs, administered by the Department of Energy and Environmental Protection (DEEP), to deal with stormwater pollution.

  1. The General Permit for the Discharge of Stormwater Associated with Industrial Activity (“Industrial General Permit”) regulates industrial facilities with point source stormwater discharges that are engaged in specific activities according to their Standard Industrial Classification (SIC) code. 

  2. The General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities ("Construction General Permit")  requires developers and builders to implement a Stormwater Pollution Control Plan to prevent the movement of sediments off construction sites into nearby water bodies and to address the impacts of stormwater discharges from a project after construction is complete. 

  3. The General Permit for the Discharge of Stormwater Associated with Commercial Activity ("Commercial General Permit"), found only in Connecticut, requires operators of large paved commercial sites such as malls, movie theaters, and supermarkets to undertake actions such as parking lot sweeping and catch basin cleaning to keep stormwater clean before it reaches water bodies.

  4. The General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems ("MS4 General Permit") requires each municipality to take steps to keep the stormwater entering its storm sewer systems clean before entering 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.

Related Guidance
Related Information


For additional information, please contact Connecticut's Stormwater Program at

Content Last Updated June 5, 2024