Wyoming tap water
1 of 31 Wyoming water systems with full PFAS testing (3%) averaged above a 2024 federal PFAS level at one or more sampling points.
- 323 active community water systems in the EPA file; 28 serve 3,300+ people and have a full PFAS set.
- 73 systems had at least one health-based violation since 2021-10-26.
- 0 systems report a lead 90th percentile above 15 ppb (some results are old; check each system page).
Largest systems
| System | People served | PFAS above a 2024 level? | Health-based violations since 2021-10-26 |
|---|---|---|---|
| Cheyenne Board of Public Utilities | 64,165 | No | 0 |
| Casper, City of | 59,000 | No | 0 |
| Laramie, City of | 32,395 | No | 0 |
| Gillette, City of | 32,222 | No | 0 |
| Jackson, Town of | 24,760 | No | 0 |
| Rock Springs, City of | 24,000 | No | 0 |
| Sheridan, City of | 22,700 | No | 0 |
| Evanston, City of | 11,727 | No | 0 |
All 2 utilities with a page in Wyoming
- Casper, City of 59,000
- Cheyenne Board of Public Utilities 64,165
Why not "the state's water quality"? You drink from one utility, not a state. Rollups count systems, not people, so one large utility counts the same as a small one. Use the system pages for your actual water.
Not medical or legal advice. UCMR 5 results are screening data, not compliance determinations.
Sources and freshness
Public-water-system facts, violations and lead/copper results: EPA ECHO SDWA download (SDWIS snapshot 2026-10-13). PFAS and lithium results: EPA UCMR 5 final data (sampling 2023–2025). Both are U.S. government works, downloaded 2026-10-26. Numbers are computed by the published method; the same fields are in the open data files.