17 plants · 26% of the state · 302 MGD combined
Klarifi identifies 17 publicly owned wastewater treatment plants with anaerobic digesters and biogas in Massachusetts, 26% of the 66 plants in the state (302 MGD combined). The largest is Deer Island Wastewater Treatment Facility in Winthrop at 233.7 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 | Deer Island Wastewater Treatment Facility | Winthrop | 233.7 | MA0103284 | Jul 2005 | 3 |
| 2 | Greater Lawrence Wastewater Treatment Facility | North Andover | 21.7 | MAL100447 | Dec 2030 | 10 |
| 3 | Brockton Advanced Water Reclamation Fac | Brockton | 9.9 | MAL101010 | Dec 2030 | 10 |
| 4 | Pittsfield Wastewater Treatment Facility | Pittsfield | 7 | MA0101681 | Oct 2026 | 84 |
| 5 | Taunton Wastewater Treatment Facility | Taunton | 5.36 | MA0100897 | Jul 2020 | 52 |
| 6 | Holyoke Water Pollution Control Facility | Holyoke | 5.02 | MAL101630 | Dec 2030 | 4 |
| 7 | Westborough Wastewater Treatment Plant | Westborough | 4.17 | MA0100412 | Apr 2027 | 2 |
| 8 | Northampton Wastewater Treatment Plant | Northampton | 3.84 | MA0101818 | Nov 2028 | 40 |
| 9 | Gardner W W T F | East Templeton | 2.28 | MAG590013 | Oct 2027 | 75 |
| 10 | Rockland Wastewater Plant | Rockland | 2 | MAG590038 | Oct 2027 | 32 |
| 11 | Erving Wastewater Treatment Plant #2 | Erving | 1.72 | MA0101052 | Nov 2026 | 36 |
| 12 | Newburyport Wastewater Treatment Facility | Newburyport | 1.45 | MAG590035 | Oct 2027 | 0 |
| 13 | Plymouth Wastewater Treatment Facility | Plymouth | 1.31 | MAG590040 | Oct 2027 | 5 |
| 14 | Hull Wastewater Treatment Plant | Hull | 1.03 | MAL101231 | Dec 2030 | 3 |
| 15 | Ipswich Wastewater Treatment Plant | Ipswich | 0.5 | MAG590036 | Oct 2027 | 2 |
| 16 | Spencer Wastewater Treatment Plant | Spencer | 0.44 | MAG590010 | Oct 2027 | 20 |
| 17 | Shelburne Wastewater Treatment Facility | Shelburne | 0.11 | MAG580002 | Nov 2026 | 24 |
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.