Wastewater treatment plants in Wyoming
58 facilities · 33 MGD combined flow
Klarifi tracks 58 publicly owned wastewater treatment plants in Wyoming with a combined average flow of 33 MGD. 9 plants treat more than 1 MGD and 0 more than 10 MGD; 44 use lagoon systems and 6 have digesters or biogas infrastructure. The largest is Sam H. Hobbs Regional WW Facility (prev. Casper Wwtf) in Casper at 6.6 MGD. 6 NPDES permits expire this year and 8 next year.
Every plant below links to a profile with average and design flow, the NPDES permit and its expiry, a three-year compliance snapshot and the capital projects planned in its city. Treatment technology and verified contacts are shown with a free Klarifi account.
58 plant locations in Wyoming; dot size follows average flow. Boundaries: U.S. Census Bureau.
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 | Violations (3y) |
|---|---|---|---|---|---|---|
| Sam H. Hobbs Regional WW Facility (prev. Casper Wwtf) | Casper | 6.6 | — | WY0021920 | Oct 2030 | 14 |
| Dry Creek Water Reclamation Facility | Cheyenne | 5.48 | — | WY0022934 | Oct 2028 | 1 |
| Gillette WWTF | Gillette | 2.88 | — | WY0020125 | Jul 2027 | 7 |
| Sheridan Wastewater Treatment | Sheridan | 2.11 | — | WY0020010 | Nov 2028 | 1 |
| Rock Springs Water Reclamation Facility | Rock Springs | 1.98 | — | WY0022357 | Mar 2029 | 19 |
| Jackson Wastewater Lagoon | Jackson | 1.93 | — | WY0021458 | Oct 2029 | 3 |
| Powell, City Of | Powell | 1.67 | — | WY0020648 | Apr 2028 | 7 |
| Lander Wastewater Lagoon | Lander | 1.11 | — | WY0020389 | Apr 2026 | 47 |
| Evanston WWTF | Evanston | 1.01 | — | WY0020095 | Aug 2029 | 0 |
| City Of Rawlins Wastewater Treatment Facility | Rawlins | 0.85 | — | WY0020427 | Apr 2026 | 6 |
Treatment technology for each plant is shown with a free Klarifi account. Create one →
Wyoming plants by treatment technology
All 58 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 October 26, 2026.
Wastewater terms: WWTP · POTW · MGD · NPDES permit · Centrate · Ozonation · 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. “Wastewater treatment plants in Wyoming.” Updated October 26, 2026. https://klarifi.io/facilities/wyomingNeed a custom cut of the data for a state, a county or a list of plants? Email info@klarifi.io.