7 plants · 13% of the state · 10 MGD combined
Klarifi identifies 7 publicly owned wastewater treatment plants with oxidation ditches in Connecticut, 13% of the 54 plants in the state (10 MGD combined). The largest is Branford Water Pollution Control Facility in Branford at 2.9 MGD.
Oxidation ditches are ring-shaped activated sludge reactors with long retention times, common at plants between 0.5 and 10 MGD. They are recognisable from the air by their looped channels and rely on surface aerators or brush rotors, which are frequent replacement and energy-efficiency projects.
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Branford Water Pollution Control Facility | Branford | 2.9 | CT0100048 | Jan 2025 | 0 |
| 2 | Glastonbury Water Pollution Control Facility | Glastonbury | 2.17 | CT0100226 | Apr 2026 | 9 |
| 3 | Simsbury Water Pollution Control Facility | Simsbury | 1.58 | CT0100919 | Feb 2024 | 2 |
| 4 | University Of Ct Water Pollution Control Facility | Storrs | 1.5 | CT0101320 | May 2023 | 4 |
| 5 | Westport WPCF | Westport | 1.46 | CT0100684 | Jul 2024 | 0 |
| 6 | New Canaan Wastewater Treatment Plant | New Canaan | 0.55 | CT0101273 | Jan 2026 | 4 |
| 7 | Newtown /wpcf | Newtown | 0.3 | CT0101788 | Aug 2021 | 20 |
Contacts and project signals for every plant on this list
Klarifi adds verified decision-maker contacts, permit limits, discharge monitoring data and the capital projects planned in each city, filterable by technology, size and compliance record.
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 September 11, 2026.