Anaerobic digesters and biogas: wastewater treatment plants in Wisconsin
146 plants · 37% of the state · 276 MGD reported by 124 plants
Klarifi identifies 146 publicly owned wastewater treatment plants with anaerobic digesters and biogas in Wisconsin, 37% of the 394 plants in the state (276 MGD reported by 124 plants). The largest is EPA Superfund Site: Madison Metropolitan Sewerage District Lagoons in Madison at 39.37 MGD.
Anaerobic digesters stabilise sludge in sealed heated tanks and produce biogas, visible from the air as digester silos and gas holders. Plants with digesters are typically above 5 MGD and are the buyers of mixing, heating, gas handling, cogeneration and dewatering equipment.
The largest plants with anaerobic digesters in Wisconsin
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | EPA Superfund Site: Madison Metropolitan Sewerage District Lagoons | Madison | 39.37 | WIG009756 | Sep 2026 | 2 |
| 2 | Green Bay Metropolitan Sewerage District | Green Bay | 36.81 | WIL065251 | Dec 2030 | 7 |
| 3 | Racine Wastewater Treatment Facility | Racine | 20.89 | WI0025194 | Sep 2019 | 6 |
| 4 | Neenah-Menasha Sewerage Commission WWTF | Menasha | 12.33 | WI0026085 | Jun 2022 | 194 |
| 5 | Janesville Wastewater Utility | Janesville | 11.03 | WI0030350 | Jun 2025 | 0 |
| 6 | Oshkosh Wastewater Treatment F | Oshkosh | 10.56 | WI0025038 | Dec 2023 | 33 |
| 7 | La Crosse City | La Crosse | 10.21 | WI0029581 | Dec 2020 | 0 |
| 8 | Fox River Water Pollution Control Center | Brookfield | 10.11 | WI0023469 | Dec 2023 | 9 |
| 9 | Appleton City WWTF | Appleton | 9.3 | WI0023221 | Mar 2022 | 7 |
| 10 | Grand Chute-Menasha West Sewer | Neenah | 6.52 | WI0024686 | Jun 2022 | 3 |
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 Wisconsin
Anaerobic digesters and biogas in other states
Anaerobic digesters and biogas in Wisconsin: 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: Anaerobic digester · Biosolids · Sludge dewatering · Centrate · Tertiary treatment · Significant industrial user · all terms