35 NPDES permits · 11 MGD combined average flow
35 publicly owned wastewater treatment plants in Oklahoma hold NPDES permits that expire during 2027, issued by Oklahoma Department of Environmental Quality. 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) |
|---|---|---|---|---|---|---|
| Poteau, City Of | Poteau | 0.88 | OK0021610 | Jan 2027 | Clarifiers, Uncovered lagoons | 4 |
| Bristow Municipal Authority | Bristow | 0.39 | OK0032549 | Jan 2027 | Aerated lagoons, Uncovered lagoons | 136 |
| Pensacola Pub Works Authority | Pensacola | 0.007 | OK0040410 | Jan 2027 | — | 7 |
| Stringtown Pwa | Stringtown | 0.003 | OK0030449 | Jan 2027 | Uncovered lagoons | 32 |
| Cyril, Town Of | Cyril | — | OK0041467 | Jan 2027 | Aerated lagoons, Uncovered lagoons | 14 |
| Depew, Town Of | Depew | — | OK0021890 | Jan 2027 | Uncovered lagoons | 29 |
| Hobart Public Works Authority | Hobart | — | OK0028649 | Jan 2027 | Uncovered lagoons | 0 |
| Mounds Pwa Wwt | Mounds | — | OK0022888 | Jan 2027 | Uncovered lagoons | 7 |
| Healdton Wwt | Healdton | 0.1 | OK0027413 | Feb 2027 | Clarifiers | 13 |
| Oologah Public Works Authority | Oologah | 0.03 | OK0034223 | Feb 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons | 196 |
| Guymon City Of | Guymon | 1.06 | OK0045713 | Mar 2027 | Clarifiers, Covered lagoons, Uncovered lagoons | 22 |
| Newcastle Public Works Auth. | Newcastle | 0.5 | OK0028614 | Mar 2027 | Clarifiers, Uncovered lagoons | 91 |
| Ochelata Utilities Authority | Ochelata | 0.06 | OK0034517 | Mar 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons | 91 |
| Checotah WWTP | Checotah | 0.3 | OK0028100 | Apr 2027 | Uncovered lagoons, Carrousels / oxidation ditches | 20 |
| Fairfax Public Works Auth | Fairfax | 0.05 | OK0029017 | Apr 2027 | Aerated lagoons, Uncovered lagoons | 33 |
| Seneca-Cayuga Tribe | Miami | 0.03 | OK0039098 | Apr 2027 | — | 0 |
| Perkins Wwt | Perkins | 0.2 | OK0028801 | May 2027 | Uncovered lagoons | 157 |
| Glenpool Wwt | Glenpool | 0.64 | OK0027138 | Jun 2027 | Uncovered lagoons | 177 |
| Morris, City Of -NW Plant | Morris | 0.05 | OK0028924 | Jun 2027 | Aerated lagoons | 39 |
| Woodward, City Of | Woodward | — | OK0034509 | Jun 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons | 0 |
| Del City Municipal Svcs. Auth | Del City | 2.08 | OK0026085 | Jul 2027 | — | 7 |
| Chickasaw Tribal Utilities Authority | Thackerville | 0.48 | OK0045721 | Jul 2027 | Aerated lagoons | 5 |
| Madill Pwa | Madill | 0.43 | OK0031721 | Jul 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons, Biogas silos | 328 |
| Shidler, City Of | Shidler | — | OK0022993 | Jul 2027 | Uncovered lagoons | 0 |
| El Reno Municipal Authority | El Reno | 1.46 | OK0100382 | Sep 2027 | Uncovered lagoons | 42 |
| Nowata, City Of | Nowata | 0.52 | OK0025470 | Sep 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons, Carrousels / oxidation ditches | 20 |
| Chouteau Pwa | Chouteau | 0.28 | OK0022764 | Sep 2027 | Uncovered lagoons | 113 |
| Cleveland South WWTP | Cleveland | 0.11 | OK0028347 | Sep 2027 | Aerated lagoons, Uncovered lagoons | 13 |
| Wewoka Public Works Authority-Wewoka WTP | Wewoka | 0.35 | OK0022659 | Oct 2027 | Aerated lagoons, Uncovered lagoons | 194 |
| Roland, Town Of | Roland | 0.35 | OK0030392 | Oct 2027 | Aerated lagoons, Uncovered lagoons | 63 |
| Quapaw Pwa | Quapaw | 0.08 | OK0028258 | Oct 2027 | Aerated lagoons, Uncovered lagoons | 33 |
| Calvin Pwa | Calvin | 0.0081 | OK0037818 | Oct 2027 | — | 28 |
| Dustin Public Works Authority | Dustin | — | OK0029050 | Oct 2027 | Aerated lagoons, Uncovered lagoons | 2 |
| Grove Msa | Grove | 0.54 | OK0028886 | Dec 2027 | Uncovered lagoons | 4 |
| Cherokee Former City Hall | Cherokee | 0.17 | OK0020052 | Dec 2027 | Uncovered lagoons | 35 |
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.