Wastewater treatment plants in Minnesota
462 facilities · 354 MGD combined flow
Klarifi tracks 462 publicly owned wastewater treatment plants in Minnesota with a combined average flow of 354 MGD, serving about 3,972,226 residents. 30 plants treat more than 1 MGD and 6 more than 10 MGD; 333 use lagoon systems and 108 have digesters or biogas infrastructure. The largest is Met Council Metropolitan WWTP in Saint Paul at 180 MGD. 28 NPDES permits expire this year and 35 next year.
Every plant below links to a profile with average and design flow, the NPDES permit and its expiry, a three-year compliance snapshot and the capital projects planned in its city. Treatment technology and verified contacts are shown with a free Klarifi account. Showing facilities 1–200 of 462 by average flow — browse the rest with the page links below.
462 plant locations in Minnesota; dot size follows average flow.
NPDES permits and renewals in Minnesota
Every plant discharges under an NPDES permit that is renewed every five years, usually with tighter limits. The renewal year is the year a plant budgets for upgrades.
Largest wastewater treatment plants in Minnesota
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| Met Council Metropolitan WWTP | Saint Paul | 180 | — | MNL029815 | Dec 2030 | 0 |
| Blue Lake Wastewater Treatment Plant | Shakopee | 26.54 | 42 | MN0029882 | Sep 2029 | 0 |
| Seneca Wastewater Treatment Plant | Eagan | 20.92 | 38 | MN0030007 | Nov 2028 | 6 |
| Met Council - Empire WWTP | Farmington | 12.05 | — | MNL045845 | Dec 2030 | 0 |
| Rochester Water Reclamation Plant | Rochester | 11.33 | 23.85 | MN0024619 | Mar 2027 | 1 |
| Saint Cloud WWTP | St. Cloud | 10.3 | — | MNL040878 | Dec 2030 | 0 |
| Met Council - Eagles Point WWTP | Cottage Grove | 6 | 11.9 | MN0029904 | Oct 2023 | 1 |
| Grand Rapids WWTP | Grand Rapids | 5.8 | 15.2 | MN0022080 | Jan 2025 | 6 |
| Moorhead Wastewater Treatment Facility | Moorhead | 3.82 | 9 | MN0049069 | Jun 2026 | 0 |
| Owatonna WWTP | Owatonna | 3.16 | 5 | MN0051284 | May 2026 | 9 |
Treatment technology for each plant is shown with a free Klarifi account. Create one →
Minnesota plants by treatment technology
All 462 plants in Minnesota
Wastewater treatment in Minnesota: 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 22, 2026.