The largest US wastewater treatment plants with anaerobic digesters
Ranked by average flow · 3,526 MGD combined
Metropolitan Water Reclamation in Chicago, Illinois tops the list at about 281.73 million gallons per day. New York (5), Texas (3), Illinois (2), Pennsylvania (2), Missouri (2) have the most plants in the top 25. Every plant links to its profile with permit and compliance data. Treatment technology is shown with a free Klarifi account.
Anaerobic digesters stabilise sludge and produce biogas, and the plants that have them are the market for mixing, heating, gas cleaning, cogeneration and dewatering equipment. This list ranks the largest plants where Klarifi’s aerial imagery review finds digester silos or gas holders, or where the EPA needs survey records anaerobic digestion.
| # | Facility | City | State | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| 1 | Metropolitan Water Reclamation | Chicago | IL | 281.73 | ILL028061 | Dec 2030 | 10 |
| 2 | Deer Island Wastewater Treatment Facility | Winthrop | MA | 270.96 | MA0103284 | Jul 2005 | 3 |
| 3 | MWRDGC Terrence J O'Brien Water Reclamation Plant | Skokie | IL | 205.79 | IL0028088 | Jul 2022 | 16 |
| 4 | Newtown Creek Water Pollution Control Plant | Brooklyn | NY | 187.2 | NY0026204 | Jun 2027 | 4 |
| 5 | Philadelphia Southwest POTW | Philadelphia | PA | 182.78 | PAL026671 | Dec 2030 | 36 |
| 6 | NYC-DEP Wards Island WPCP | Manhattan | NY | 182.4 | NY0026131 | Jun 2027 | 26 |
| 7 | Met Council Metropolitan WWTP | Saint Paul | MN | 164.27 | MNL029815 | Dec 2030 | 0 |
| 8 | Northeast WPCP | Philadelphia | PA | 153.22 | PAL026689 | Dec 2030 | 0 |
| 9 | Village Creek Reclamation Facility | Arlington | TX | 147.27 | TX0047295 | Jan 2029 | 3 |
| 10 | Point Loma Wastewater Treatment Plant | San Diego | CA | 140.8 | CA0107409 | Apr 2031 | 1689 |
| 11 | Dos Rios Water Recycling Center | San Antonio | TX | 124.77 | TX0077801 | Jun 2025 | 44 |
| 12 | Hunts Point Water Pollution Control Plant | Bronx | NY | 123.8 | NY0026191 | Jun 2027 | 11 |
| 13 | Metropolitan St. Louis Sewer District Bissell Point WWTP | St. Louis | MO | 123.06 | MO0025178 | Aug 2031 | 14 |
| 14 | City Of Dallas Central WWTP | Dallas | TX | 118.1 | TX0047830 | Apr 2027 | 11 |
| 15 | Central District Wastewater Treatment Plant | Key Biscayne | FL | 117.2 | FL0024805 | Dec 2025 | 65 |
| 16 | Southerly Wastewater Treatment Plant | Lockbourne | OH | 112.28 | OHL024741 | Dec 2030 | 9 |
| 17 | Southerly Wastewater Treatment Center | Cleveland | OH | 110.09 | OHL024651 | Dec 2030 | 4 |
| 18 | Back River Wastewater Treatment Plant | Baltimore | MD | 107.68 | MDL021555 | Dec 2030 | 32 |
| 19 | Metro West Point | Seattle | WA | 106.93 | WAL029181 | Dec 2030 | 275 |
| 20 | Metropolitan St. Louis Sewer District Lemay WWTP | St. Louis | MO | 105.45 | MO0025151 | Aug 2031 | 6 |
| 21 | Indianapolis Belmont WWTP | Indianapolis | IN | 105.33 | IN0023183 | May 2029 | 117 |
| 22 | Nycdep - Bowery Bay WRRF | Astoria | NY | 95.2 | NY0026158 | Jun 2027 | 8 |
| 23 | Owls Head Water Pollution Control Plant | Brooklyn | NY | 88 | NY0026166 | Jun 2027 | 9 |
| 24 | Middlesex County Utilities Authority | Sayreville | NJ | 87.51 | NJ0020141 | Jun 2020 | 21 |
| 25 | 91st Avenue WWTP | Tolleson | AZ | 83.69 | AZ0020524 | Apr 2028 | 2 |
Treatment technology for each plant is shown with a free Klarifi account. Create one →
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