11 NPDES permits · 2 MGD combined average flow
11 publicly owned wastewater treatment plants in Wisconsin hold NPDES permits that expire during 2026, issued by Wisconsin Department of Natural Resources. 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) |
|---|---|---|---|---|---|---|
| Jefferson Wastewater Treatment | Jefferson | 1.06 | WI0024333 | Mar 2026 | Clarifiers, Biogas silos, Biogas balloons | 0 |
| Port Washington WWTP | Port Washington | 1.04 | WI0020460 | Mar 2026 | Clarifiers, Biogas silos, Biogas balloons | 20 |
| Reeseville Wastewater Treatment Facility | Reeseville | 0.16 | WI0028509 | Mar 2026 | Aerated lagoons | 17 |
| Crivitz Wastewater Treatment Facility | Crivitz | 0.09 | WI0060372 | Mar 2026 | Uncovered lagoons, Biogas balloons | 1 |
| Cashton Wastewater Treatment Facility | Cashton | 0.08 | WI0020915 | Mar 2026 | — | 0 |
| Wauzeka Wastewater Treatment Facility | Wauzeka | 0.02 | WI0022276 | Mar 2026 | Biogas balloons | 0 |
| Lowell Wastewater Treatment Facility | Lowell | 0.02 | WI0029271 | Mar 2026 | — | 0 |
| Burnett Sanitary District #1 WWTF | Burnett | 0.01 | WI0031551 | Mar 2026 | Aerated lagoons, Uncovered lagoons | 1 |
| Grand View Sanitary District | Grand View | 0.0038 | WI0035131 | Mar 2026 | — | 25 |
| Sheboygan Wastewater Treatment Plant | Sheboygan | — | WI0025411 | Mar 2026 | Clarifiers, Biogas silos, Biogas balloons | 1 |
| Lac Courte Oreilles | Hayward | 0.005 | WI0073041 | Oct 2026 | — | 268 |
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.