The 14 largest wastewater treatment plants in Rhode Island
Ranked by average flow · 50 MGD combined · 100% of the state's reported flow
Narragansett Bay Commission Bucklin Point in East Providence (rumford) is the largest publicly owned wastewater treatment plant in Rhode Island by reported average flow, treating about 17.77 million gallons per day. The 14 plants below treat 50 MGD between them, 100% of the flow reported by all 14 plants in the state, and serve about 378,973 people. Every plant links to its profile with permit and compliance data. Treatment technology is shown with a free Klarifi account.
| # | Facility | City | Avg flow (MGD) | Population | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| 1 | Narragansett Bay Commission Bucklin Point | East Providence (rumford) | 17.77 | 121,400 | RIR50T002 | Aug 2029 | 8 |
| 2 | Cranston Water Pollution Control Facility | Cranston | 7.48 | 73,200 | RIL100013 | Dec 2030 | 5 |
| 3 | Newport Water Pollution Control Facility | Newport | 7.15 | 41,600 | RI0100293 | May 2020 | 24 |
| 4 | East Providence WWTF | East Providence | 5.45 | 46,100 | RI0100048 | Sep 2028 | 70 |
| 5 | Bristol Wastewater Treatment Facility | Bristol | 3.17 | 20,700 | RI0100005 | Mar 2028 | 29 |
| 6 | Westerly Wastewater Treatment Facility | Westerly | 1.97 | 16,500 | RI0100064 | Sep 2026 | 7 |
| 7 | Warren WWTF | Warren | 1.78 | 8,000 | RI0100056 | Dec 2030 | 56 |
| 8 | Smithfield Wastewater Treatment Plant | Smithfield | 1.64 | 14,000 | RI0100251 | Jun 2026 | 3 |
| 9 | Burrillville Wastewater Treatment Plant | Burrillville | 0.86 | 9,700 | RI0100455 | Jun 2025 | 39 |
| 10 | East Greenwich WWTF | East Greenwich | 0.82 | 6,000 | RI0100030 | Sep 2023 | 31 |
| 11 | Quonset Point Wastewater Treatment Facility | North Kingstown | 0.6 | 11,593 | RI0100404 | Dec 2030 | 74 |
| 12 | Scarborough Wastewater Treatment Facility | Narragansett | 0.56 | 7,300 | RI0100188 | Sep 2028 | 113 |
| 13 | Jamestown Wastewater Treatment Facility | Jamestown | 0.29 | 2,100 | RI0100366 | Jun 2029 | 124 |
| 14 | New Shoreham WWTF | New Shoreham | 0.13 | 780 | RI0100196 | Jun 2029 | 149 |
Treatment technology for each plant is shown with a free Klarifi account. Create one →
Largest plants 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 October 26, 2026.
Wastewater terms: WWTP · POTW · MGD · NPDES permit · Oxidation ditch · Anaerobic digester · all terms
Cite this page
Journalists, researchers and educators are welcome to quote these figures. Please credit Klarifi as the source and link to this page.
Klarifi. “Largest wastewater treatment plants in Rhode Island (2026).” Updated October 26, 2026. https://klarifi.io/facilities/rhode-island/largestNeed a custom cut of the data for a state, a county or a list of plants? Email info@klarifi.io.