Lagoon systems: wastewater treatment plants in Maine
30 plants · 36% of the state · 3 MGD reported by 16 plants
Klarifi identifies 30 publicly owned wastewater treatment plants with lagoon systems in Maine, 36% of the 84 plants in the state (3 MGD reported by 16 plants). The largest is Anson Madison Wastewater Treatment Facility in Madison at 0.6 MGD.
Lagoon systems treat wastewater in large earthen ponds over weeks of retention time, with or without mechanical aeration. They serve thousands of small towns because they are cheap to run, but they struggle with ammonia and nutrient limits, fill with sludge over decades and are the plants most often converted or upgraded when a permit is renewed.
The largest lagoons in Maine
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Anson Madison Wastewater Treatment Facility | Madison | 0.6 | ME0101389 | Apr 2031 | 2 |
| 2 | Ogunquit Wastewater Treatment Facility | Ogunquit | 0.54 | ME0100986 | Nov 2023 | 8 |
| 3 | Skowhegan Wastewater Treatment Facility | Skowhegan | 0.31 | ME0100625 | Apr 2031 | 90 |
| 4 | Ft Fairfield Wastewater Treatment Facility | Fort Fairfield | 0.16 | ME0100226 | May 2022 | 11 |
| 5 | Fort Kent WWTF | Fort Kent | 0.15 | ME0102369 | Dec 2021 | 2 |
| 6 | Newport Wastewater Treatement Facility | Newport | 0.14 | ME0100447 | Mar 2028 | 2 |
| 7 | Limerick WWTF | Limerick | 0.11 | ME0100871 | Oct 2020 | 64 |
| 8 | Milo Wastewater Treatment Facility | Milo | 0.08 | ME0100439 | Mar 2028 | 10 |
| 9 | Hartland Wastewater Treatment Facility | Hartland | 0.08 | ME0101443 | May 2023 | 0 |
| 10 | Bethel Wastewater Treatment Facility | Bethel | 0.08 | ME0101176 | Dec 2027 | 42 |
| 11 | Veazie WWTF | Veazie | 0.07 | ME0100706 | Sep 2030 | 13 |
| 12 | Warren Wastewater Treatment Facility | Warren | 0.07 | ME0102253 | Mar 2030 | 0 |
| 13 | Washburn Wastewater Treatment Facility | Washburn | 0.05 | ME0101028 | Sep 2029 | 4 |
| 14 | Ashland Wastwater Treatment Facility | Ashland | 0.04 | ME0101087 | May 2027 | 31 |
| 15 | Frenchville Wastewater Treatment Facility | Frenchville | 0.04 | ME0101982 | Sep 2029 | 124 |
| 16 | Thomaston Waste Water Treatment Facility | Thomaston | 0.003 | ME0100668 | Sep 2023 | 3 |
| 17 | Canton Wastewater Treatment Facility | Canton | — | ME0102067 | Oct 2029 | 4 |
| 18 | Clinton WWTF | Clinton | — | ME0101699 | Jun 2030 | 0 |
| 19 | Dexter Utility District | Dexter | — | MEU500830 | Aug 2028 | 3 |
| 20 | Dover-Foxcroft Wastewater Treatment Facility | Dover-Foxcroft | — | ME0100501 | Feb 2028 | 5 |
| 21 | Howland WWTF | Howland | — | ME0101788 | Mar 2021 | 0 |
| 22 | Jackman Wastewater Treatment Facility | Jackman | — | ME0100978 | Oct 2024 | 0 |
| 23 | Mattawamkeag WWTF | Mattawamkeag | — | ME0102245 | Apr 2028 | 2 |
| 24 | Moosehead Sanitary District | Greenville | — | MEU502119 | Jul 2025 | 69 |
| 25 | Norway Wastewater Treatment Facility | Norway | — | ME0100455 | Aug 2030 | 0 |
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 Maine
Lagoon systems in other states
Lagoon systems in Maine: 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.