New Industrial Stormwater General Permit for CT

The Connecticut Department of Energy and Environmental Protection (DEEP) has announced a 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.

Sites currently covered by the former permit have until April 1, 2026 to register for the new permit. 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 reregister under the new permit. If at any time industrial activity on a site is modified and industrial activity outdoors occurs, the facility must submit a registration for an IGP and comply with the operating conditions of the permit.

Sites will need to review their Stormwater Pollution Prevention Plans (SWPPPs) to ensure that they are in compliance with the requirements of the new permit. 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 affecting the potential for a spill to reach US navigable waters or shorelines.

If you need help renewing your permit or assessing whether a permit is still required for your facility, contact Walden today. We can also assist in updating your SWPPP and SPCC Plan. Our staff is experienced in site audits, stormwater management, and permit compliance. Give us a call at 860-846-4069 or email our EHS Director at dgarner@walden-associates.com to learn more!