CTState-AdministeredSWPPP Requirements in Connecticut
Connecticut administers its own NPDES program under CT DEEP. A new Construction Stormwater General Permit took effect January 1, 2026, with a five-year term through December 31, 2030. Most of Connecticut drains to Long Island Sound, triggering enhanced nutrient and sediment protections. Inland Wetlands permits from local commissions are required separately for any wetland or watercourse impact.
Connecticut SWPPP Key Facts
- ✓2026–2030 Construction Stormwater General Permit — register through DEEP per current requirements
- ✓$0 NOI filing fee
- ✓Long Island Sound watershed protections apply statewide
- ✓Inland Wetlands permits required from local municipalities for wetland impacts
- ✓SWPPP must be on-site and available for inspection at all times
Administering Agency
- Agency
- Connecticut Department of Energy and Environmental Protection (CT DEEP)
- Phone
- 860-424-3018
- deep.stormwater@ct.gov
- Website
- CT DEEP Stormwater Program
Permit Details
- Permit Name
- General Permit for the Discharge of Stormwater from Construction Activities (Construction Stormwater General Permit)
- Effective Date
- 2026-01-01
- Expiration Date
- 2030-12-31
- Permit Document
- View Current Permit
SWPPP Thresholds & Triggers
- Acreage Threshold
- 1 acre or more; less than 1 acre if part of a larger common plan of development
Long Island Sound watershed protections apply to most of Connecticut. Inland Wetlands and Watercourses Act permits required separately from Inland Wetlands Commissions for wetland impacts.
Inspection Requirements
- Inspection Frequency
- At least every 7 days and within 24 hours of a 0.5-inch or greater storm event
- Rain Event Threshold
- 0.5 inches within 24 hours
- Certified Inspector
- Not required by state
Coverage is obtained through DEEP's registration process (ezFile) per the current Construction Stormwater General Permit. Inland Wetlands permits are issued by local Inland Wetlands Commissions, not DEEP.
Penalties & Enforcement
- Max Civil Penalty (Per Day)
- $25,000 per day per violation
- Criminal Penalties
- Up to $25,000/day and imprisonment for willful violations
CT DEEP and local Inland Wetlands Commissions share enforcement jurisdiction; simultaneous violations possible.
Permit Fees
- NOI Filing Fee
- $0
- Other Fees
- Inland Wetlands permit fees paid to local municipality (varies)
How Connecticut Differs from Federal Requirements
- ⚠CT has its own NPDES program; EPA CGP does not apply
- ⚠Inland Wetlands Commission permit layer is CT-specific
- ⚠Long Island Sound nutrient reduction requirements exceed federal CGP
- ⚠$0 NOI fee versus potential fees under EPA-administered states
SWPPP Tips for Connecticut
- ➤Contact your local Inland Wetlands Commission early — review timelines vary by town
- ➤Confirm registration deadlines and any interim-coverage rules on the DEEP Construction Stormwater GP page before mobilizing
- ➤Include Long Island Sound-specific BMPs in SWPPP narratives for nitrogen and phosphorus reduction
Connecticut SWPPP FAQs
When did Connecticut's new Construction Stormwater General Permit take effect?+
The reissued Construction Stormwater General Permit became effective January 1, 2026, and expires December 31, 2030. Sites that were covered under the prior permit must follow DEEP's transition instructions (registration in ezFile, NOT, or new coverage as directed).
Do I need both a CT CGP NOI and an Inland Wetlands permit?+
Yes, if your project impacts inland wetlands or watercourses. These are separate permits from different authorities — CT DEEP for CGP, local Inland Wetlands Commission for wetland impacts.
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