Anaerobic digesters and biogas: US wastewater treatment plants
1,571 plants in 49 states · 8,410 MGD reported by 1,334 plants · 2 planning upgrades
Klarifi identifies 1,571 publicly owned wastewater treatment plants with anaerobic digesters and biogas in the United States (8,410 MGD reported by 1,334 plants). The largest is Deer Island Wastewater Treatment Facility in Winthrop, MA at 233.7 MGD. Each state below links to its own list with every plant.
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.
Anaerobic digesters and biogas by state
144 plants
137 plants
115 plants
106 plants
96 plants
94 plants
93 plants
78 plants
69 plants
68 plants
59 plants
34 plants
31 plants
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2 plants
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1 plants
1 plants
The largest plants with anaerobic digesters in the US
Other treatment technologies
Anaerobic digesters and biogas: 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.