13 plants · 25% of the state · 157 MGD reported by 9 plants
Klarifi identifies 13 publicly owned wastewater treatment plants with anaerobic digesters and biogas in Arizona, 25% of the 53 plants in the state (157 MGD reported by 9 plants). The largest is 91st Avenue WWTP in Tolleson at 78.71 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.
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | 91st Avenue WWTP | Tolleson | 78.71 | AZ0020524 | Apr 2028 | 2 |
| 2 | 23rd Avenue Wastewater Treatment Plant | Phoenix | 35.67 | AZ0020559 | Jun 2029 | 2 |
| 3 | Pima County - Ina Road WWTP | Tucson | 31.89 | AZ0020001 | May 2027 | 3 |
| 4 | Yuma, City Of - Figueroa Ave WPCF | Yuma | 7.27 | AZ0020443 | Aug 2028 | 14 |
| 5 | Town Of Prescott Valley - WWTP | Prescott Valley | 2.74 | AZ0025381 | Feb 2027 | 0 |
| 6 | City Of Peoria | Peoria | 0.23 | AZ0024945 | Jul 2027 | 17 |
| 7 | Town Of Kearny Wastewater Reclamation Facility | Kearny | 0.1 | AZ0024449 | Jul 2026 | 49 |
| 8 | Tusayan Sanitary District | Grand Canyon | 0.03 | AZ0026719 | Aug 2027 | 0 |
| 9 | City Of Mesa - Greenfield Water Reclamation Plant | Gilbert | 0.03 | AZ0025241 | Sep 2029 | 0 |
| 10 | Agua Nueva WRF | Tucson | — | AZ0026107 | Apr 2028 | 0 |
| 11 | City Of Winslow - WWTP | Winslow | — | AZ0026310 | Feb 2031 | 0 |
| 12 | Pima County - Wwmd - Green Valley Bnro - WWTP | Sahuarita | — | AZ0024937 | Mar 2031 | 0 |
| 13 | Tolleson WWTP | Tolleson | — | AZ0020338 | Feb 2031 | 30 |
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.
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.