All 28 systems had complete monitoring. 1 reached at least one study comparison level; 27 did not. “Study comparison level” means the dated EPA technical cutoff used in this January 2026 research release. It does not determine household exposure, health risk, or current legal compliance.
Find your water system
ZIP codes are used only to route visitors to public water systems that reported serving them. Confirm the actual provider using a water bill or utility record.
System counts in Wyoming
Each count shows how many included water systems reached the named study level.
| Study comparison | Systems reaching level | Water systems included | Percent |
|---|---|---|---|
| PFOA: study level 4.05 ppt (April 2024 EPA level: 4 ppt) | 0 | 28 | 0.0% |
| PFOS: study level 4.05 ppt (April 2024 EPA level: 4 ppt) | 0 | 28 | 0.0% |
| PFHxS: study level 15 ppt (April 2024 EPA level: 10 ppt) | 1 | 28 | 3.6% |
| PFNA: study level 15 ppt (April 2024 EPA level: 10 ppt) | 0 | 28 | 0.0% |
| HFPO-DA: study level 15 ppt (April 2024 EPA level: 10 ppt) | 0 | 28 | 0.0% |
| Hazard Index: study level 1.5 with at least two detected components (April 2024 EPA level: 1) | 1 | 28 | 3.6% |
Community water systems with complete monitoring
Each PWSID appears once, preventing double counting across ZIP associations.
| Public water system | PWSID | Population served | Primary source | Sampling locations | Study comparison |
|---|---|---|---|---|---|
| CASPER, CITY OF | WY5601415 | 59,000 | Surface water purchased | 2 | Below the study levels |
| CHEYENNE BOARD OF PUBLIC UTILITIES | WY5600011 | 64,165 | Surface water | 2 | Below the study levels |
| DOUGLAS, CITY OF | WY5600137 | 6,400 | Surface water | 3 | Below the study levels |
| EVANSTON, CITY OF | WY5600150 | 11,727 | Surface water | 1 | Below the study levels |
| FIRST FIKE SUBDIVISION | WY5600194 | 150 | Ground water | 2 | Below the study levels |
| FORT WASHAKIE | 085690003 | 2,620 | Surface water | 4 | Below the study levels |
| GILLETTE, CITY OF | WY5600019 | 32,222 | Ground water | 2 | Below the study levels |
| GREEN RIVER, CITY OF | WY5601181 | 10,500 | Surface water purchased | 1 | Below the study levels |
| GTNP-COLTER BAY VILLAGE | WY5680095 | 4,514 | Ground water | 1 | Below the study levels |
| HIGH MEADOW RANCH | WY5601569 | 580 | Ground water | 1 | Below the study levels |
| JACKSON, TOWN OF | WY5600213 | 24,760 | Ground water | 3 | Below the study levels |
| LANDER, CITY OF | WY5600176 | 7,615 | Surface water | 1 | Below the study levels |
| LARAMIE, CITY OF | WY5600029 | 32,395 | Surface water | 4 | Below the study levels |
| LOVELL, TOWN OF | WY5600031 | 2,250 | Surface water purchased | 1 | Below the study levels |
| MILLS, TOWN OF | WY5600036 | 4,050 | Groundwater under influence of surface water | 1 | Below the study levels |
| NEWCASTLE, CITY OF | WY5600256 | 3,595 | Ground water | 5 | Below the study levels |
| NORTHWEST RURAL WATER DISTRICT, WY | WY5601254 | 7,330 | Surface water purchased | 1 | Below the study levels |
| POWELL, CITY OF | WY5600042 | 6,310 | Surface water purchased | 1 | Below the study levels |
| RAWLINS WATER SUPPLY, CITY OF | WY5600045 | 9,006 | Surface water | 1 | Below the study levels |
| RIVERTON, CITY OF | WY5600047 | 10,330 | Surface water | 15 | Reached a study level |
| ROCK SPRINGS, CITY OF | WY5601182 | 24,000 | Surface water purchased | 1 | Below the study levels |
| SHERIDAN WY, CITY OF | WY5600052 | 22,700 | Surface water | 2 | Below the study levels |
| SOUTH CHEYENNE WATER & SEWER DISTRICT | WY5600239 | 10,000 | Surface water purchased | 1 | Below the study levels |
| TORRINGTON MUNICIPAL WS | WY5600164 | 6,847 | Ground water | 2 | Below the study levels |
| USAF F.E. WARREN AFB | WY5680122 | 5,500 | Surface water purchased | 1 | Below the study levels |
| WHEATLAND, TOWN OF | WY5600187 | 3,659 | Ground water | 3 | Below the study levels |
| WORLAND UTILITIES COMMISSION | WY5600197 | 4,787 | Ground water | 1 | Below the study levels |
| YNP-OLD FAITHFUL | WY5680085 | 7,675 | Surface water | 1 | Below the study levels |
What is included
Each active community water system with complete monitoring is counted once, even if it is linked with several ZIP codes. Private wells are excluded, and UCMR 5 did not comprehensively monitor every small system. This page does not apply Wyoming's state-specific standards or determine compliance. Use the official state or territory drinking-water program for current regulatory information.