The Connecticut Department of Energy and Environmental Protection (DEEP) has announced the reissuance of the Industrial Stormwater General Permit (IGP). This general permit authorizes discharges from certain industrial activities and facilities based upon a site’s Standard Industrial Classification (SIC) Code. 

The previous permit expired on September 30, 2025, and the new permit was issued on October 1, 2025. Now that the new permit is active, CT DEEP will accept registrations for a new permit or notice of non-exposure starting November 1, 2025.  

The deadline to register for the new permit for sites currently covered by the former permit is April 1, 2026. New sites must apply at least 90 days prior to the initial discharge. Sites with new owners or operators must register within 30 days of the transfer date, and existing permittees must submit a notice of termination. If a facility is registered, owned, or leased under another name or by a municipality, the operator is responsible for submitting the registration.  

The “No Exposure” exemption from the previous permit has been carried over to the new permit. Facilities registered as “Non-Exposure” will need to re-register under the new permit. If at any time industrial activity on a site is modified and industrial activity occurs outdoors, the facility must submit an IGP registration and comply with the permit's operating conditions.  

Sites will need to update their Stormwater Pollution Prevention Plans (SWPPPs) and have them certified by a CHMM or state-licensed Professional Engineer (P.E.) to ensure compliance with the new permit requirements. This is also a good time to review your Spill Prevention, Control, and Countermeasure (SPCC) Plans, which must be updated every five years or whenever a significant change occurs on site that could affect the potential for a spill to reach U.S. navigable waters or shorelines.  

“In addition to the Industrial Stormwater General Permit, DEEP has also updated the Commercial Stormwater General Permit,” said David Garner, Walden’s EHS Director. “That is significant, too, because it has not been updated for many years. Of course, it is important to understand what applies at your facility.”  

For More Information

If you have questions about these changes, including how they may impact your business, our stormwater management experts in Connecticut can help. Contact David Garner, CSP, CHMM, SMP, our EHS Director in CT at (203) 710-4376 or email him at [email protected].