Activated sludge and clarifiers: wastewater treatment plants in Rhode Island
13 plants · 93% of the state · 40 MGD combined
Klarifi identifies 13 publicly owned wastewater treatment plants with activated sludge and clarifiers in Rhode Island, 93% of the 14 plants in the state (40 MGD combined). The largest is Narragansett Bay Commission Bucklin Point in East Providence (rumford) at 16.27 MGD.
Activated sludge is the standard mechanical process for cities: aeration basins where bacteria consume organic matter, followed by clarifiers that settle the biomass out. These plants are identified by their circular or rectangular clarifiers and by the suspended-growth process code, and they are the main market for blowers, diffusers, clarifier mechanisms and instrumentation.
The largest activated sludge plants in Rhode Island
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Narragansett Bay Commission Bucklin Point | East Providence (rumford) | 16.27 | RIR50T002 | Aug 2029 | 8 |
| 2 | Cranston Water Pollution Control Facility | Cranston | 5.3 | RIL100013 | Dec 2030 | 6 |
| 3 | Newport Water Pollution Control Facility | Newport | 5.3 | RI0100293 | May 2020 | 24 |
| 4 | East Providence WWTF | East Providence | 4.4 | RI0100048 | Sep 2028 | 70 |
| 5 | Bristol Wastewater Treatment Facility | Bristol | 2.14 | RI0100005 | Mar 2028 | 25 |
| 6 | Westerly Wastewater Treatment Facility | Westerly | 1.56 | RI0100064 | Sep 2026 | 7 |
| 7 | Smithfield Wastewater Treatment Plant | Smithfield | 1.35 | RI0100251 | Jun 2026 | 3 |
| 8 | Warren WWTF | Warren | 1.19 | RI0100056 | Dec 2030 | 56 |
| 9 | Burrillville Wastewater Treatment Plant | Burrillville | 0.66 | RI0100455 | Jun 2025 | 36 |
| 10 | East Greenwich WWTF | East Greenwich | 0.63 | RI0100030 | Sep 2023 | 7 |
| 11 | Quonset Point Wastewater Treatment Facility | North Kingstown | 0.41 | RI0100404 | Dec 2030 | 74 |
| 12 | Scarborough Wastewater Treatment Facility | Narragansett | 0.39 | RI0100188 | Sep 2028 | 113 |
| 13 | Jamestown Wastewater Treatment Facility | Jamestown | 0.1 | RI0100366 | Jun 2029 | 112 |
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.
Other technologies in Rhode Island
Activated sludge and clarifiers in other states
Activated sludge and clarifiers in Rhode Island: questions
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.