NPDES permits in Wyoming
56 permits held by publicly owned wastewater treatment plants · issued by WDEQ
Effective
48
Administratively continued
1
Expired
6
Total tracked
56
Wyoming Department of Environmental Quality (WDEQ) runs the NPDES program in Wyoming under delegation from EPA Region 8, issuing and enforcing the discharge permits listed here. Klarifi tracks 56 permits held by publicly owned treatment plants in the state, with status, expiry, design flow and three-year compliance for each. Agency website →
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.
Permit renewals by year
Largest permit holders in Wyoming
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Status | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| Pine Bluffs Wastewater Lagoon | Pine Bluffs | 10 | — | WY0032212 | Effective | Apr 2029 | 273 |
| Sam H. Hobbs Regional WW Facility (prev. Casper Wwtf) | Casper | 6.67 | — | WY0021920 | Effective | Oct 2030 | 13 |
| Dry Creek Water Reclamation Facility | Cheyenne | 4.8 | — | WY0022934 | Effective | Oct 2028 | 1 |
| Gillette WWTF | Gillette | 2.92 | — | WY0020125 | Effective | Jul 2027 | 7 |
| Sheridan Wastewater Treatment | Sheridan | 2.21 | — | WY0020010 | Effective | Nov 2028 | 1 |
| Powell, City Of | Powell | 2.09 | — | WY0020648 | Effective | Apr 2028 | 7 |
| Rock Springs Water Reclamation Facility | Rock Springs | 2 | — | WY0022357 | Effective | Mar 2029 | 19 |
| Jackson Wastewater Lagoon | Jackson | 1.94 | — | WY0021458 | Effective | Oct 2029 | 3 |
| Lander Wastewater Lagoon | Lander | 1.24 | — | WY0020389 | Expired | Apr 2026 | 43 |
| Evanston WWTF | Evanston | 0.96 | — | WY0020095 | Effective | Aug 2029 | 0 |
| Buffalo WWTP | Buffalo | 0.79 | — | WY0021024 | Effective | Oct 2026 | 0 |
| Worland Wastewater Lagoon | Worland | 0.71 | — | WY0020176 | Effective | Apr 2027 | 0 |
| Cody Wastewater Lagoon | Cody | 0.6 | — | WY0020451 | Effective | Jan 2030 | 1 |
| Basin Wastewater Lagoon | Basin | 0.55 | — | WY0020028 | Effective | Dec 2026 | 38 |
| Douglas Wastewater Lagoon | Douglas | 0.49 | — | WY0020109 | Effective | Oct 2030 | 4 |
| Torrington Wastewater Lagoons | Torrington | 0.46 | — | WY0020231 | Effective | Jul 2029 | 18 |
| Lyman Wastewater Lagoon | Lyman | 0.4 | — | WY0020117 | Effective | Sep 2027 | 47 |
| Green River Wastewater Treatment Plant | Green River | 0.37 | — | WY0020443 | Effective | Jun 2031 | 13 |
| Marbleton Wastewater Lagoon | Marbleton | 0.31 | — | WY0021997 | Expired | Mar 2024 | 158 |
| Chief Washakie Recreation Comp | Fort Washakie | 0.1 | 0.3 | WYG589101 | Effective | Mar 2027 | 84 |
| Thermopolis WWTF | Thermopolis | 0.3 | — | WY0020192 | Effective | Aug 2030 | 20 |
| Hudson Wastewater Lagoon | Hudson | 0.25 | — | WY0020664 | Effective | Nov 2028 | 6 |
| Kemmerer Wastewater Treatment | Kemmerer | 0.23 | — | WY0020320 | Effective | Aug 2028 | 43 |
| Moorcroft Wastewater Lagoon | Moorcroft | 0.21 | — | WY0021741 | Effective | Jan 2031 | 28 |
| Mountain View Wastewater Lagoon | Mountain View | 0.2 | — | WY0022896 | Effective | Apr 2030 | 48 |
NPDES permits in Wyoming: 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.