Activated sludge and clarifiers: wastewater treatment plants in New York
179 plants · 39% of the state · 1,134 MGD reported by 165 plants
Klarifi identifies 179 publicly owned wastewater treatment plants with activated sludge and clarifiers in New York, 39% of the 461 plants in the state (1,134 MGD reported by 165 plants). The largest is Newtown Creek Water Pollution Control Plant in Brooklyn at 188 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 New York
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Newtown Creek Water Pollution Control Plant | Brooklyn | 188 | NY0026204 | Jun 2027 | 5 |
| 2 | NYC-DEP Wards Island WPCP | Manhattan | 174 | NY0026131 | Jun 2027 | 25 |
| 3 | Hunts Point Water Pollution Control Plant | Bronx | 109 | NY0026191 | Jun 2027 | 11 |
| 4 | Nycdep - Bowery Bay WRRF | Astoria | 94 | NY0026158 | Jun 2027 | 10 |
| 5 | Jamaica Water Pollution Control Plant | Jamaica | 70 | NY0026115 | Jun 2027 | 10 |
| 6 | Cedar Creek WPCP | Wantagh | 62.2 | NY0026859 | Jan 2026 | 12 |
| 7 | Tallman Island Wastewater Treatment Plant | Queens | 57 | NY0026239 | Jun 2027 | 2 |
| 8 | Bay Park Sewage Treatment Plant | East Rockaway | 48.5 | NY0026450 | Jan 2026 | 4 |
| 9 | Albany County Sewer District - South Plant | Albany | 45.11 | NY0026867 | Feb 2030 | 49 |
| 10 | Bergen Point STP & Bergen Ave Dock | W Babylon | 26.7 | NY0104809 | Dec 2019 | 81 |
| 11 | Port Richmond Water Pollution Control Plant | Staten Island | 21 | NY0026107 | Jun 2027 | 4 |
| 12 | Rensselaer County Sd#1 WWTP | Troy | 15.63 | NY0087971 | May 2030 | 9 |
| 13 | Tonawanda (t) Sd#2 WWTP | Tonawanda | 11.7 | NY0026395 | Jun 2019 | 9 |
| 14 | Schenectady (c) STP | Schenectady | 11.1 | NY0020516 | Dec 2025 | 3 |
| 15 | NW Quadrant Pure Waters Dist WWTP | Hilton | 10.3 | NY0028231 | Jan 2019 | 2 |
| 16 | Erie County Southtowns Sewage Treatment Plant | Buffalo | 9.5 | NY0095401 | Sep 2017 | 61 |
| 17 | New Rochelle STP | New Rochelle | 9 | NY0026697 | Oct 2017 | 1 |
| 18 | Lockport (c) WWTP | Lockport | 6.55 | NY0027057 | Aug 2017 | 13 |
| 19 | City Of Poughkeepsie Water Pollution Control Plant | Poughkeepsie | 6.18 | NY0026255 | Dec 2028 | 5 |
| 20 | Newburgh (c) WWTP | Newburgh | 5.4 | NY0026310 | May 2029 | 51 |
| 21 | Amsterdam (c) WWTP | Amsterdam | 5.35 | NY0020290 | Feb 2021 | 57 |
| 22 | Watertown Pollution Control Plant | Watertown | 5.21 | NY0025984 | Jan 2016 | 24 |
| 23 | Plattsburgh (c) WPCP | Plattsburgh | 5.2 | NY0026018 | Oct 2022 | 1 |
| 24 | Orangetown Town Of Sewer Dept | Orangeburg | 5.18 | NY0026051 | Jan 2022 | 6 |
| 25 | Village Of Endicott Water Polution Control Plant | Endicott | 4.81 | NY0027669 | Apr 2029 | 24 |
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 New York
Activated sludge and clarifiers in other states
Activated sludge and clarifiers in New York: 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.