Michigan wastewater permits expiring in 2026
25 NPDES permits · 46 MGD combined average flow
25 publicly owned wastewater treatment plants in Michigan hold NPDES permits that expire during 2026, issued by Michigan Department of Environment, Great Lakes, and Energy. The table lists each plant with its permit number, expiry month, average flow, treatment technology and three-year violation count, in order of expiry.
An NPDES permit runs for five years. To keep discharging, a plant must apply for renewal at least 180 days before the expiry date, and the renewed permit usually arrives with tighter effluent limits, new monitoring requirements or a compliance schedule. That is why the year a permit expires is the year a plant starts budgeting for upgrades: nutrient removal, disinfection, capacity or controls.
| Facility | City | Avg flow (MGD) | NPDES permit | Expires | Technology | Violations (3y) |
|---|---|---|---|---|---|---|
| Southgate-Wyandotte Cso Rtf | Wyandotte | 16.88 | MI0036072 | Oct 2026 | Clarifiers, Biogas silos, Biogas balloons | 2 |
| Milk River Cso Rtb | Grosse Pointe Woods | 7.7 | MI0025500 | Oct 2026 | — | 46 |
| Cbpu Waste Water Treatment Plant | Coldwater | 3.2 | MI0020117 | Oct 2026 | Clarifiers, Uncovered lagoons, Biogas silos, Biogas balloons | 9 |
| Zeeland WWTP | Zeeland | 2.5 | MI0020524 | Oct 2026 | Clarifiers, Biogas silos | 8 |
| Commerce Twp WWTP | Walled Lake | 2.13 | MI0025071 | Oct 2026 | Clarifiers, Aerated lagoons, Uncovered lagoons, Carrousels / oxidation ditches | 0 |
| Owosso/mid Shiawassee Co WWTP | Owosso | 2.09 | MI0023752 | Oct 2026 | Clarifiers, Biogas balloons | 29 |
| Alpena WWTP | Alpena | 2.01 | MI0022195 | Oct 2026 | Clarifiers, Biogas silos, Biogas balloons | 9 |
| Oakland Co Walled Lk Novi WWTP | Novi | 1.98 | MI0024287 | Oct 2026 | — | 3 |
| Genoa-Oceola WWTP | Howell | 1.36 | MI0055654 | Oct 2026 | Clarifiers, Carrousels / oxidation ditches | 1 |
| Sturgis WWTP | Sturgis | 1.13 | MI0020451 | Oct 2026 | Clarifiers, Uncovered lagoons, Biogas silos, Biogas balloons | 2 |
| Three Rivers WWTP | Three Rivers | 0.88 | MI0020991 | Oct 2026 | Clarifiers, Biogas silos | 46 |
| Chelsea WWTP | Chelsea | 0.85 | MI0020737 | Oct 2026 | Clarifiers, Carrousels / oxidation ditches | 0 |
| Cheboygan WWTP | Cheboygan | 0.84 | MI0020303 | Oct 2026 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches, Biogas silos | 16 |
| St Clair WWTP | St Clair | 0.72 | MI0020591 | Oct 2026 | Biogas silos, Biogas balloons | 0 |
| Holly WWTP | Holly | 0.54 | MI0020184 | Oct 2026 | Biogas silos | 67 |
| Rogers City WWTP | Rogers City | 0.44 | MI0057813 | Oct 2026 | Clarifiers, Biogas silos | 5 |
| Howell Twp WWTP | Howell | 0.3 | MI0055727 | Oct 2026 | Clarifiers, Uncovered lagoons | 1 |
| Chesaning WWTP | Chesaning | 0.25 | MI0020087 | Oct 2026 | Clarifiers, Biogas silos | 6 |
| Jonesville WWTP | Jonesville | 0.23 | MI0020109 | Oct 2026 | Clarifiers, Biogas silos, Biogas balloons | 1 |
| Hudson WWTP | Hudson | 0.19 | MI0021377 | Oct 2026 | — | 0 |
| Luna Pier WWTP | Luna Pier | 0.19 | MI0058821 | Oct 2026 | Clarifiers | 2 |
| Salem Twp WWTP | Salem | 0.02 | MI0054798 | Oct 2026 | Clarifiers | 14 |
| Belding WWTP | Belding | — | MI0020851 | Oct 2026 | Uncovered lagoons | 52 |
| Ithaca Wwsl | Ithaca | — | MI0056928 | Oct 2026 | Uncovered lagoons | 35 |
| Standish WWTP | Standish | — | MI0024139 | Oct 2026 | Aerated lagoons, Uncovered lagoons | 13 |
Michigan permit renewals in 2026: 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.