Connecticut NPDES permit search
Status, expiry and violations for 54 municipal wastewater permits · issued by DEEP as Surface Water Discharge permits
In short
How do I look up an NPDES permit in Connecticut?
Search this page by permit number or plant name for a municipal plant’s permit status, expiry date and violations. For the official file, search EPA’s list of Connecticut permits or DEEP’s notices of proposed permits. EPA’s ECHO database shows the monitoring results and violations of every permit. The 224 industrial permits in Connecticut are listed in Klarifi with a free account.
Links to official sources checked September 2026.
Effective
8
Administratively continued
22
Expired
24
Plants with effluent violations, 3 years
43
Where to find official Connecticut NPDES records
Connecticut Department of Energy and Environmental Protection (DEEP) runs the NPDES program in Connecticut under authorization from EPA Region 1. It issues and enforces the permits, which it calls Surface Water Discharge permits, and keeps the official file: applications, permits, fact sheets and monitoring reports. EPA New England issues the permits on tribal lands. DEEP website ↗
permits · permit documents
DEEP’s own list of issued permits does not cover discharge permits, so EPA New England’s table is the online list. Type the town, facility name or permit number (for example CT0028631) and click the facility for the final permit.
permit documents · applications
DEEP’s notices of proposed permits, newest first, with the draft permit and fact sheet attached where available.
permits · DMRs · inspections · violations · enforcement
EPA’s Enforcement and Compliance History Online. Search water facilities by permit number, name or city; the Detailed Facility Report lists inspections, violations and enforcement actions, and Effluent Charts plot monitoring results against the permit limits.
- Permit numbers
- Permits follow EPA’s format (CT0028631); DEEP identifies pending applications by an application number such as 202408089.
- Discharge monitoring reports
- Through EPA’s NetDMR, after signing a DEEP subscriber agreement.
- Violations and enforcement
- DEEP’s formal enforcement case summaries ↗ and DEEP’s enforcement map ↗
Industrial and commercial NPDES permits in Connecticut
Most NPDES permits are not held by municipal plants. EPA’s permit database lists 224 individual permits in force for industrial and commercial facilities in Connecticut (manufacturers, food processors, mines, power plants, landfills), 20 of them major dischargers, plus 302 facilities covered by a general permit, mostly for stormwater. 49 of the individual permits recorded at least one effluent violation in the last three years.
| Facility | Permit | Status | Expires | Effluent violations |
|---|
Unlock 224 industrial permits in Connecticut
Search every industrial and commercial discharger in Connecticut by name or permit number, with permit status, expiry and violation history. Free with a Klarifi account.
Industrial and commercial NPDES permits in Connecticut: permits in force (effective or administratively continued) held by facilities EPA does not class as publicly owned treatment works or federal facilities. Source: EPA ICIS-NPDES via Klarifi, October 2026.
Violations at Connecticut wastewater plants
43 of the 54 municipal plants on this page recorded at least one effluent violation, a monitored value above a permit limit, in the last three years, and 47 had a violation of any kind, including late or missing monitoring reports. Each plant’s page shows its own count. EPA’s enforcement records list 22 formal cases naming Connecticut wastewater plants, 0 of them since fiscal year 2020, with $2 million in penalties assessed. Enforcement cases in Connecticut →
Permit renewals by year
An NPDES permit runs for five years. To keep discharging, a plant must apply for renewal at least 180 days before the expiry date, and the renewed permit usually arrives with tighter effluent limits, new monitoring requirements or a compliance schedule. That is why the year a permit expires is the year a plant starts budgeting for upgrades: nutrient removal, disinfection, capacity or controls.
Largest permit holders in Connecticut
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Status | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| Hartford Water Pollution Control Facility | Hartford | 56.89 | — | CTL000004 | Effective | Dec 2030 | 3 |
| Westside Water Pollution Control Facility | Bridgeport | 17.54 | 30 | CT0100056 | Administratively continued | Jun 2024 | 65 |
| Stamford Water Pollution Control Facility | Stamford | 13.83 | 24 | CT0101087 | Expired | Dec 2023 | 10 |
| Norwalk WPCF | East Norwalk | 11.32 | 18 | CT0101249 | Expired | Mar 2026 | 10 |
| Danbury Water Pollution Control Facility | Danbury | 9.24 | 15.5 | CT0100145 | Expired | Jun 2026 | 5 |
| Greenwich WPCF | Greenwich | 6.44 | 12.5 | CT0100234 | Administratively continued | Jul 2024 | 4 |
| Meriden Water Pollution Control Facility | Meriden | 9.93 | 11.6 | CT0100315 | Expired | Dec 2023 | 10 |
| Stratford Water Pollution Control Facility | Stratford | 7.32 | 11.5 | CT0101036 | Expired | Sep 2025 | 36 |
| Enfield Water Pollution Control Facility | Enfield | 3.97 | 10 | CT0100200 | Administratively continued | Jul 2024 | 0 |
| Piacenti Wastewater Treatment Plant | New London | 6.48 | 10 | CT0100382 | Effective | Apr 2027 | 8 |
Connecticut NPDES permits: questions
NPDES permit search in other states
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed October 12, 2026.
Wastewater terms: NPDES permit · POTW · Significant industrial user · MGD · Inflow and infiltration · Sludge dewatering · all terms