Wastewater Treatment Plants in Wyoming
56 facilities · 42 MGD combined flow
Klarifi tracks 56 publicly owned wastewater treatment plants in Wyoming with a combined average flow of 42 MGD. 9 plants treat more than 1 MGD and 1 more than 10 MGD; 43 use lagoon systems and 6 have digesters or biogas infrastructure. The largest is Pine Bluffs Wastewater Lagoon in Pine Bluffs at 10 MGD. 6 NPDES permits expire this year and 8 next year.
Every plant below links to a profile with average and design flow, treatment technology, the NPDES permit and its expiry, a three-year compliance snapshot and the capital projects planned in its city.
56 plant locations in Wyoming; dot size follows average flow.
NPDES permits and renewals in Wyoming
Every plant discharges under an NPDES permit that is renewed every five years, usually with tighter limits. The renewal year is the year a plant budgets for upgrades.
Largest wastewater treatment plants in Wyoming
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Expires | Technology | Violations (3y) |
|---|---|---|---|---|---|---|---|
| Pine Bluffs Wastewater Lagoon | Pine Bluffs | 10 | — | WY0032212 | Apr 2029 | Uncovered lagoons | 273 |
| Sam H. Hobbs Regional WW Facility (prev. Casper Wwtf) | Casper | 6.67 | — | WY0021920 | Oct 2030 | Clarifiers, Uncovered lagoons, Biogas silos | 13 |
| Dry Creek Water Reclamation Facility | Cheyenne | 4.8 | — | WY0022934 | Oct 2028 | Clarifiers, Biogas silos | 1 |
| Gillette WWTF | Gillette | 2.92 | — | WY0020125 | Jul 2027 | Clarifiers, Uncovered lagoons, Biogas silos, Biogas balloons | 7 |
| Sheridan Wastewater Treatment | Sheridan | 2.21 | — | WY0020010 | Nov 2028 | — | 1 |
| Powell, City Of | Powell | 2.09 | — | WY0020648 | Apr 2028 | — | 7 |
| Rock Springs Water Reclamation Facility | Rock Springs | 2 | — | WY0022357 | Mar 2029 | Clarifiers, Carrousels / oxidation ditches, Biogas silos, Biogas balloons | 19 |
| Jackson Wastewater Lagoon | Jackson | 1.94 | — | WY0021458 | Oct 2029 | Aerated lagoons, Uncovered lagoons | 3 |
| Lander Wastewater Lagoon | Lander | 1.24 | — | WY0020389 | Apr 2026 | Aerated lagoons, Uncovered lagoons | 43 |
| Evanston WWTF | Evanston | 0.96 | — | WY0020095 | Aug 2029 | Carrousels / oxidation ditches, Biogas balloons | 0 |
| Buffalo WWTP | Buffalo | 0.79 | — | WY0021024 | Oct 2026 | Uncovered lagoons | 0 |
| Worland Wastewater Lagoon | Worland | 0.71 | — | WY0020176 | Apr 2027 | — | 0 |
| Cody Wastewater Lagoon | Cody | 0.6 | — | WY0020451 | Jan 2030 | Aerated lagoons, Covered lagoons | 1 |
| Basin Wastewater Lagoon | Basin | 0.55 | — | WY0020028 | Dec 2026 | Uncovered lagoons | 38 |
| Douglas Wastewater Lagoon | Douglas | 0.49 | — | WY0020109 | Oct 2030 | Covered lagoons, Uncovered lagoons | 4 |
| Torrington Wastewater Lagoons | Torrington | 0.46 | — | WY0020231 | Jul 2029 | Aerated lagoons, Uncovered lagoons | 18 |
| Lyman Wastewater Lagoon | Lyman | 0.4 | — | WY0020117 | Sep 2027 | Aerated lagoons | 47 |
| Green River Wastewater Treatment Plant | Green River | 0.37 | — | WY0020443 | Jun 2031 | Aerated lagoons, Uncovered lagoons | 13 |
| Marbleton Wastewater Lagoon | Marbleton | 0.31 | — | WY0021997 | Mar 2024 | Aerated lagoons, Covered lagoons, Uncovered lagoons | 158 |
| Thermopolis WWTF | Thermopolis | 0.3 | — | WY0020192 | Aug 2030 | — | 20 |
| Hudson Wastewater Lagoon | Hudson | 0.25 | — | WY0020664 | Nov 2028 | — | 6 |
| Kemmerer Wastewater Treatment | Kemmerer | 0.23 | — | WY0020320 | Aug 2028 | Carrousels / oxidation ditches, Biogas balloons | 43 |
| Moorcroft Wastewater Lagoon | Moorcroft | 0.21 | — | WY0021741 | Jan 2031 | Aerated lagoons, Uncovered lagoons | 28 |
| Mountain View Wastewater Lagoon | Mountain View | 0.2 | — | WY0022896 | Apr 2030 | Aerated lagoons, Uncovered lagoons | 48 |
| Hartville Wastewater Treatment | Hartville | 0.14 | — | WY0021440 | Jun 2025 | — | 0 |
Wyoming plants by treatment technology
All 56 plants in Wyoming
Wastewater treatment 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.