29 NPDES permits · 0 MGD combined average flow
29 publicly owned wastewater treatment plants in South Dakota hold NPDES permits that expire during 2026, issued by South Dakota Department of Agriculture and 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 | Violations (3y) |
|---|---|---|---|---|---|
| Groton, City Of | Groton | — | SD0022187 | Mar 2026 | 8 |
| Menno, City Of | Menno | — | SD0020087 | Mar 2026 | 19 |
| Toronto, Town Of | Toronto | — | SD0021571 | Mar 2026 | 32 |
| Veblen, City Of | Veblen | — | SD0020001 | Mar 2026 | 105 |
| Armour, City Of | Armour | — | SD0020222 | Apr 2026 | 19 |
| Avon, City Of | Avon, City Of | — | SD0022730 | Apr 2026 | 120 |
| White River - City Of | White River | — | SD0022063 | Apr 2026 | 0 |
| Selby, City Of | Selby | — | SD0021717 | May 2026 | 84 |
| Eagle Butte WWTF | Eagle Butte | — | SD0020192 | Jun 2026 | 8 |
| Kimball, City Of | Kimball | — | SD0022772 | Jun 2026 | 42 |
| Leola, City Of | Leola | — | SD0022667 | Jun 2026 | 9 |
| Wessington Springs, City Of | Wessington Springs | — | SD0020460 | Jun 2026 | 19 |
| Iroquois, City Of | Iroquois | 0.14 | SDG922438 | Aug 2026 | 33 |
| Labolt, Town Of | Labolt | 0.06 | SDG926662 | Aug 2026 | 114 |
| Claremont, Town Of | Claremont | 0.05 | SDG922314 | Aug 2026 | 128 |
| Andover, Town Of | Andover | — | SDG921504 | Aug 2026 | 112 |
| Bonesteel- City Of | Bonesteel | — | SDG920842 | Aug 2026 | 2 |
| Bristol, City Of | Bristol | — | SDG822420 | Aug 2026 | — |
| Cavour, Town Of | Cavour | — | SDG921806 | Aug 2026 | 2 |
| Hitchcock, Town Of | Hitchcock | — | SDG926051 | Aug 2026 | 1 |
| Hurley - City Of | Hurley | — | SDG821997 | Aug 2026 | — |
| Langford, Town Of | Langford | — | SDG922705 | Aug 2026 | 22 |
| Lesterville, Town Of | Lesterville | — | SDG922373 | Aug 2026 | 80 |
| Mellette , City Of | Mellette | — | SDG920672 | Aug 2026 | 4 |
| Murdo, City Of | Murdo | — | SDG920818 | Aug 2026 | 16 |
| Reliance - Town Of | Reliance | — | SDG920231 | Aug 2026 | 48 |
| Stickney, Town Of | Stickney | — | SDG921491 | Aug 2026 | 0 |
| Tea, City Of | Tea, City Of | — | SDG921784 | Aug 2026 | 3 |
| Tyndall, City Of | Tyndall | — | SDG920133 | Aug 2026 | 0 |
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 October 26, 2026.
Wastewater terms: NPDES permit · POTW · Biological nutrient removal · Tertiary treatment · WWTP · Biosolids · all terms
Cite this page
Journalists, researchers and educators are welcome to quote these figures. Please credit Klarifi as the source and link to this page.
Klarifi. “NPDES permits expiring in 2026: South Dakota plants.” Updated October 26, 2026. https://klarifi.io/facilities/south-dakota/permits-expiring/2026Need a custom cut of the data for a state, a county or a list of plants? Email info@klarifi.io.