The 50 largest wastewater treatment plants in New Jersey
Ranked by average flow · 471 MGD combined · 98% of the state's reported flow
Middlesex County Utilities Authority in Sayreville is the largest publicly owned wastewater treatment plant in New Jersey by reported average flow, treating about 77.42 million gallons per day. The 50 plants below treat 471 MGD between them, 98% of the flow reported by all 122 plants in the state, and serve about 5,137,652 people. Every plant links to its profile with permit, technology and compliance data.
| # | Facility | City | Avg flow (MGD) | Population | NPDES permit | Expires | Technology | Violations (3y) |
|---|---|---|---|---|---|---|---|---|
| 1 | Middlesex County Utilities Authority | Sayreville | 77.42 | 924,565 | NJ0020141 | Jun 2020 | Clarifiers, Uncovered lagoons, Biogas silos | 17 |
| 2 | Bergen County Utilities Authority | Little Ferry | 63.2 | 575,131 | NJ0020028 | Mar 2030 | Clarifiers, Uncovered lagoons, Biogas silos | 176 |
| 3 | Essex & Union Cnty Joint Meeting STP | Elizabeth | 44.93 | 421,182 | NJ0024741 | Mar 2030 | Clarifiers, Carrousels / oxidation ditches, Biogas silos | 145 |
| 4 | Delaware #1 Water Pollution Control Facility | Camden | 43.19 | 468,135 | NJ0026182 | Dec 2029 | Biogas silos, Biogas balloons | 6 |
| 5 | Atlantic County Utilities Authority POTW | Atlantic City | 24.52 | 233,690 | NJL024473 | Dec 2030 | Clarifiers, Uncovered lagoons, Biogas silos | 0 |
| 6 | Ocean Cnty Util Auth Nwpcf | Bricktown | 22.16 | 368,408 | NJ0028142 | Mar 2026 | Clarifiers, Biogas silos, Biogas balloons | 0 |
| 7 | Rahway Valley Sewerage Authority | Rahway | 19.3 | 162,793 | NJL024643 | Dec 2030 | Clarifiers, Biogas silos, Biogas balloons | 77 |
| 8 | Ocean Cnty Util Auth Cwpcf | Bayville | 17.6 | 273,851 | NJL029408 | Dec 2030 | Clarifiers, Biogas silos, Biogas balloons | 0 |
| 9 | Gloucester Cnty Util Auth STP | West Deptford Twp | 15.16 | 215,126 | NJ0024686 | Dec 2026 | Clarifiers, Biogas silos | 15 |
| 10 | Somerset Raritian Valley Sewerage | Bridgewater | 12.98 | 117,267 | NJ0024864 | Nov 2030 | Clarifiers | 9 |
| 11 | Monmouth Cnty Bayshore Outfall Auth Belford Pump Station | Belford | 12.8 | — | NJ0024694 | Sep 2026 | Clarifiers, Biogas silos | 3 |
| 12 | North Hudson Sewerage Auth WWTP | Hoboken | 11.5 | 123,752 | NJ0026085 | Mar 2029 | Clarifiers, Biogas balloons | 0 |
| 13 | Trenton City DPW Sewer Auth | Trenton | 9.42 | 82,957 | NJ0020923 | Mar 2026 | — | 127 |
| 14 | Rockaway Valley Reg Sa | Boonton | 9.09 | 118,040 | NJ0022349 | Sep 2024 | Clarifiers, Carrousels / oxidation ditches | 117 |
| 15 | Par Troy Hills Twp MUA WWTP @ Whippany River | Parsippany | 7.98 | 87,340 | NJG124753 | Jan 2028 | Clarifiers, Biogas silos | 88 |
| 16 | Middletown Twp Slf Belford Section | Middletown | 7.01 | 74,244 | NJ0025356 | Dec 2025 | Clarifiers, Aerated lagoons, Biogas silos | 4 |
| 17 | Pine Brook STP | Manalapan | 5.83 | 42,340 | NJ0023728 | Sep 2026 | Clarifiers, Biogas silos, Biogas balloons | 0 |
| 18 | Township Of Wayne | Wayne | 5.72 | 53,163 | NJ0028002 | Mar 2026 | Clarifiers | 38 |
| 19 | Ewing Lawrence Sewer Auth | Lawrenceville | 5.5 | 86,707 | NJ0024759 | Sep 2023 | Clarifiers, Biogas silos, Biogas balloons | 96 |
| 20 | Two Bridges Wastewater Treatment Plant | Lincoln Park | 4.45 | 62,048 | NJ0029386 | Sep 2025 | Clarifiers | 0 |
| 21 | Bergen County Utilities Authority | Edgewater | 3.52 | 14,396 | NJ0020591 | Apr 2017 | Clarifiers, Biogas silos | 151 |
| 22 | Willingboro Water Pollution Control Plant | Willingboro | 3 | 45,079 | NJ0023361 | Dec 2030 | Clarifiers, Biogas silos | 8 |
| 23 | Caldwell Boro MUA Caldwell WWTP | West Caldwell | 2.98 | 33,305 | NJ0020427 | Sep 2028 | Clarifiers, Carrousels / oxidation ditches, Biogas balloons | 68 |
| 24 | Cape May Cnty MUA 7 Mile Beach Middle Rgnl Wtf | Cape May Court House | 2.88 | 33,605 | NJ0052990 | Jun 2026 | Uncovered lagoons, Biogas balloons | 2 |
| 25 | Cape May Cnty MUA Ocean City WWTP | Ocean City | 2.57 | 13,896 | NJ0035343 | Jun 2026 | Clarifiers | 10 |
| 26 | Morristown Sewer Utility | Morristown | 2.57 | 19,229 | NJ0025496 | Mar 2026 | Clarifiers, Biogas silos | 12 |
| 27 | North Bergen Twp MUA Woodcliff STP | North Bergen | 2.41 | 39,015 | NJ0029084 | Jun 2028 | Clarifiers, Biogas balloons | 17 |
| 28 | East Windsor Water Pollution Control Plant | East Windsor | 2.38 | 27,181 | NJ0023787 | Mar 2027 | Clarifiers, Uncovered lagoons | 86 |
| 29 | Long Branch City Sewer Auth | Long Branch | 2.29 | 30,210 | NJ0024783 | Dec 2025 | Biogas silos, Biogas balloons | 0 |
| 30 | Asbury Park Water Quality Central Facility | Asbury Park | 2.08 | 15,377 | NJ0025241 | Mar 2026 | — | 51 |
| 31 | Musconetcong Sewer Auth Water Pollution Control Facility | Budd Lake | 2.07 | 33,532 | NJ0027821 | Mar 2026 | Clarifiers, Biogas silos | 12 |
| 32 | Molitor Water Pollution Control Facility | Chatham | 1.91 | 26,212 | NJ0024937 | Dec 2029 | Clarifiers, Aerated lagoons, Uncovered lagoons, Carrousels / oxidation ditches, Biogas silos | 170 |
| 33 | Delran Sewerage Authority | Delran | 1.87 | 16,476 | NJ0023507 | Sep 2028 | — | 37 |
| 34 | Elmwood WTP | Marlton | 1.73 | 24,329 | NJ0024040 | Jun 2031 | Clarifiers, Carrousels / oxidation ditches | 20 |
| 35 | Maple Shade Twp Util Auth Park Avenue POTW | Maple Shade | 1.71 | 18,463 | NJ0069167 | Sep 2029 | Clarifiers, Biogas silos | 27 |
| 36 | Logan Township MUA | Bridgeport | 1.46 | 19,144 | NJ0027545 | Sep 2028 | Clarifiers, Aerated lagoons, Uncovered lagoons | 2 |
| 37 | Pemberton Twp MUA | Pemberton | 1.45 | 38,344 | NJ0024821 | Jun 2025 | Clarifiers, Biogas silos | 34 |
| 38 | Harrison Brook STP | Liberty Corner | 1.29 | 27,025 | NJ0022845 | Mar 2027 | Clarifiers, Aerated lagoons, Carrousels / oxidation ditches | 6 |
| 39 | Cinnaminson Twp Sewerage Auth | Cinnaminson | 1.28 | 16,602 | NJ0024007 | Dec 2027 | Clarifiers | 16 |
| 40 | Roxbury Twp MUA Ajax WTP | Succasunna | 1.23 | 22,773 | NJ0022675 | Mar 2025 | Clarifiers | 27 |
| 41 | Sussex Cnty MUA Upper Wallkill Valley Water Pollution Control Facility | Hamburg | 1.21 | 44,856 | NJ0053350 | Sep 2023 | Clarifiers | 77 |
| 42 | Cape May Regional Wtf | Cape May Point | 1.18 | 14,798 | NJ0020371 | Jun 2031 | Clarifiers, Biogas balloons | 9 |
| 43 | Berkeley Heights WPCF | Berkeley Heights | 1.15 | 13,313 | NJ0027961 | Mar 2028 | Clarifiers, Biogas silos | 133 |
| 44 | Butterworth Water Pollution Control Utility | Morristown | 1.08 | 15,068 | NJ0024911 | Sep 2026 | — | 2 |
| 45 | Long Hill Township STP | Stirling | 0.9 | 8,382 | NJ0024465 | Sep 2023 | Clarifiers, Carrousels / oxidation ditches | 60 |
| 46 | Chatham Twp DPW Main STP Water Pollution Control Plant | Chatham | 0.71 | 10,107 | NJ0020290 | Dec 2030 | Clarifiers, Aerated lagoons, Carrousels / oxidation ditches, Biogas silos | 64 |
| 47 | Wanaque Valley Rgnl Sewer Auth Treatment Plant | Wanaque | 0.65 | 11,717 | NJ0053759 | Jun 2027 | Clarifiers, Carrousels / oxidation ditches | 38 |
| 48 | Newton Town DPW | Newton | 0.61 | 7,977 | NJ0020184 | Mar 2023 | Clarifiers, Aerated lagoons | 50 |
| 49 | Ac Wagner Youth Corr Fac | Chesterfield | 0.6 | — | NJ0026719 | Jun 2030 | — | 314 |
| 50 | Lambertville City Sewer Auth | Lambertville | 0.6 | 6,502 | NJ0020915 | Mar 2030 | Biogas balloons | 441 |
Largest plants in New Jersey: 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.