Connecticut Department of Energy & Environmental Protection

Industrial Stormwater General Permit

The NPDES General Permit for the Discharge of Stormwater Associated with Industrial Activity regulates the discharge of stormwater from industrial facilities to surface waters of Connecticut. 

The Industrial General Permit (IGP) was created to provide consistent regulatory coverage for a wide range of industries, while allowing flexibility for sector-specific requirements. Its primary goal is pollution prevention—ensuring that pollutants are controlled at the source before they can reach waterways.

Rather than focusing on costly cleanup after pollution occurs, the IGP emphasizes proactive solutions. Facilities must implement Best Management Practices and Stormwater Control Measures designed to reduce or eliminate potential sources of contamination. This preventative approach is both more effective and more economical in protecting water quality.

No dumping drains to river
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 Industrial Stormwater General Permit Document

**The Industrial Stormwater General Permit was issued October 1, 2025**

**Registration Opens November 1, 2025**

Tip: The permit includes Smart Navigation - integrated smart links for fast and seamless navigation. One-click access to key sections.

Registration Timeline & Deadlines
Registration Deadlines for Existing Permittees & Sites
  • Existing Permittees: Sites covered under the previous permit are required to register by April 1, 2026
  • Interim Permit coverage is provided by the Agency provided a complete & timely application is received
                                                       

     

    Registration for New Sites & New Owners
    • New Sites: Sites constructed after the permit effective date are required to register at least 90 days prior to initiating an industrial discharge
    • New Owners
      • This general permit is non-transferable
      • Sites with new owners or operators must register within 30 days of the transfer date and existing permittees must submit a Notice of Termination

 Registration Process & How to Apply

Starting November 1, 2025, you can register online using the enhanced 'ezFile' system!

Get started Today!  Click the link below to access the 'ezFile Portal' online and submit your application in just a few easy steps.

Submit an Application ezFile Online Application Portal

Explore the Application User Guide provided in the ‘Application Resource’ section below for a complete, step-by-step process. The Stormwater Program Team is available to address technical questions related to the information required by the permit. They do not provide IT support and are unable to assist with account, login, or system-related issues. To ensure timely assistance for both you and the community, please contact the appropriate support team for IT-related inquiries. 

Need Assistance with ezFile:

For support with ezFile, please visit the DEEP Help Site: https://filings.deep.ct.gov/DEEPPortal/Help/Index

or contact the DEEP Help Desk by email at Deep.helpdesk.footprints@ct.gov

Important Information:

  • The Stormwater Program Team is available to address technical questions related to the information required by the permit. They do not provide IT support and are unable to assist with account, login, or system-related issues. To ensure timely assistance for both you and the community, please contact the appropriate support team for IT-related inquiries.
  • For issues concerning account setup, access, or login, please contact the dedicated IT Support Team.

Business Hours: Monday through Friday, 8:00 a.m. to 4:30 p.m. (EST), excluding state holidays.

Due to anticipated high volume of inquiries, responses may take up to 2–3 business days. Your patience is appreciated.

  • Fees
    • $625 or $1,250 depending on employee count and gross sales
    • The municipal fee is 50% of the regular rate
    • Fees are non-refundable
  • Before you apply you will need the following information
    • Operator and facility details
    • SIC/NAICS codes
    • Site location and drainage information
    • Receiving water body information
    • NDDB and Coastal Consistency reviews
    • All discharge points
  • Application Resources
  • What to Expect
    • It will take approximately 90 to 180 days to process the application
    • Incomplete applications will result in processing delays or rejections
    • DEEP expects a high volume of permits in the first 2 years of the permit term that may lead to delays in processing time
    • You will receive a Notice of Coverage from the DEEP confirming permit coverage
  • Notice of Change (NOC)
    • Submission of a NOC is required if there is a change in contact information or if the site is adding or removing discharge locations
  • Notice of Termination
    • Submission of a NOT is required if any of the following criteria are met:
      • A new owner or operator has received authorization to discharge under this permit
      • The permittee of the facility has submitted and been approved for a No Exposure Certification (NEC)
      • The Permittee has modified the site such that all stormwater is retained on-site and there are no discharges or stormwater to surface waters of the state either directly or indirectly through an MS4
      • The permittee has ceased operations at the facility, there will no longer be discharges of stormwater associated with industrial activity from the facility, no materials associated with the industrial activity remain exposed to stormwater, and all sediment and erosion controls have been implemented as necessary (see Section 4.2.9)
      • The facility falls under Sector J (Non-metallic Mineral Mining) and has met the applicable termination requirements per state and local regulations
      • The permittee has obtained coverage under an individual or alternative general permit for all discharges required to be authorized by a NPDES permit (unless DEEP revokes coverage for the permittee's facility).

Permit Requirements

  • Stormwater Pollution Prevention Plan (SWPPP)
    • SWPPP Basics: A SWPPP is a facility-specific living plan developed to identify stormwater pollution risks and outline BMPs and control measures.
    • DEEP's new SWPPP Template makes it easier than ever to save time, cut costs, and get quick approval.  Click here to download: SWPPP Template

Noncompliance Reporting:

  • Report instances of noncompliance online here: Stormwater Noncompliance Reporting assistance tools are available online here: CT DEEP Compliance Assistance

Resources and Contact Information
Compliance Assistance
Environmental Protection Agency
Contact Information

 

Stormwater Management

Content Last Updated December 4, 2025