Lagoon systems: wastewater treatment plants in North Dakota
195 plants · 99% of the state · 25 MGD reported by 5 plants
Klarifi identifies 195 publicly owned wastewater treatment plants with lagoon systems in North Dakota, 99% of the 197 plants in the state (25 MGD reported by 5 plants). The largest is Grand Forks City Of in Grand Forks at 8.82 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 North Dakota
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Grand Forks City Of | Grand Forks | 8.82 | ND0022888 | Dec 2028 | 7 |
| 2 | Bismarck City Of (potw) | Bismarck | 7.66 | ND0023434 | Jun 2028 | 0 |
| 3 | City Of Minot - Minot Landfill | Minot | 4.26 | ND0022896 | Mar 2030 | 19 |
| 4 | Williston City Of | Williston | 2.88 | ND0022349 | Mar 2028 | 4 |
| 5 | Mandan Landfill / Ts | Mandan | 1.77 | ND0022861 | Sep 2026 | 0 |
| 6 | Adams City Of | Adams City | — | NDG323094 | Sep 2029 | 18 |
| 7 | Amenia City Of | Amenia | — | NDG323477 | Sep 2029 | 29 |
| 8 | Anamoose City Of | Anamoose | — | NDG321725 | Sep 2029 | 10 |
| 9 | Aneta City Of | Aneta | — | NDG321296 | Sep 2029 | 9 |
| 10 | Antler City Of | Antler | — | NDG323302 | Sep 2029 | 0 |
| 11 | Argusville City Of | Argusville | — | NDG322535 | Sep 2029 | 9 |
| 12 | Arnegard, City Of | Arnegard | — | NDG321733 | Sep 2029 | 9 |
| 13 | Arthur | Arthur | — | NDG321415 | Sep 2029 | 9 |
| 14 | Ashley City Of | Ashley | — | NDG322152 | Sep 2029 | 4 |
| 15 | Barney City Of | Barney | — | NDG322195 | Sep 2029 | 27 |
| 16 | Belfield Lagoon | Belfield | — | ND0022144 | Jun 2031 | 15 |
| 17 | Berthold City Of | Berthold | — | NDG321938 | Sep 2029 | 36 |
| 18 | Beulah City Of | Beulah | — | ND0021211 | Jun 2028 | 11 |
| 19 | Binford City Of | Binford | — | NDG321431 | Sep 2029 | 9 |
| 20 | Bisbee City Of | Bisbee | — | NDG323574 | Sep 2029 | 0 |
| 21 | Bowdon City Of | Bowdon | — | NDG320664 | Sep 2029 | 27 |
| 22 | Bowman Lagoon | Bowman | — | ND0021342 | Jun 2031 | 14 |
| 23 | Bullhead Lagoon | Fort Yates | — | NDG589308 | Mar 2027 | — |
| 24 | Butte City Of | Butte | — | NDG320206 | Sep 2029 | 27 |
| 25 | Buxton City Of | Buxton | — | NDG322993 | Sep 2029 | 1 |
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.
Lagoon systems in other states
Lagoon systems in North Dakota: 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.