All 32 systems met the sampling requirement for a yearly average. Of those systems, 1 had at least one yearly average above an EPA comparison level and 31 did not.
EPA-based study benchmark: a fixed, unrounded research cutoff used to reproduce EPA’s final UCMR 5 technical-assistance classification based on the April 2024 federal levels. It is not a current federal or state standard. The label does not determine compliance, household exposure, or health risk.
State rules: The labels on this page use fixed research cutoffs based on the April 2024 federal levels. Wyoming may use different current standards or guidance. These UCMR 5 results do not determine current federal or state compliance. Find the official Wyoming drinking-water program →
Find your water system
A ZIP code finds possible public water systems for an area; it cannot identify the supplier for a specific home. Confirm the provider using a water bill or utility record.
System counts in Wyoming
Each count shows how many included water systems had a yearly average above the named EPA comparison level.
| EPA rounding cutoff | Systems above comparison level | Water systems included | Percent |
|---|---|---|---|
| PFOA: 4 ppt level; unrounded average ≥4.05 ppt after applying EPA rounding | 0 | 32 | 0.0% |
| PFOS: 4 ppt level; unrounded average ≥4.05 ppt after applying EPA rounding | 0 | 32 | 0.0% |
| PFHxS: 10 ppt level; unrounded average ≥15 ppt after applying EPA rounding | 1 | 32 | 3.1% |
| PFNA: 10 ppt level; unrounded average ≥15 ppt after applying EPA rounding | 0 | 32 | 0.0% |
| HFPO-DA: 10 ppt level; unrounded average ≥15 ppt after applying EPA rounding | 0 | 32 | 0.0% |
| Hazard Index: 1 level; unrounded index ≥1.5 and at least two detected components | 1 | 32 | 3.1% |
Community water systems with complete monitoring
“Complete monitoring” means at least one sampling location had every required sample needed to calculate a yearly average. It does not mean every location or home was tested. Each PWSID appears once, preventing double counting across ZIP associations.
| Public water system | PWSID | Population served | Primary source | Sampling locations | EPA comparison result |
|---|---|---|---|---|---|
| BUFFALO, CITY OF | WY5600005 | 4,419 | Surface water | 1 | No available average above comparison levels |
| CASPER, CITY OF | WY5601415 | 59,000 | Surface water purchased | 2 | No available average above comparison levels |
| CHEYENNE BOARD OF PUBLIC UTILITIES | WY5600011 | 64,165 | Surface water | 2 | No available average above comparison levels |
| CODY, CITY OF | WY5600207 | 10,224 | Surface water purchased | 1 | No available average above comparison levels |
| DOUGLAS, CITY OF | WY5600137 | 6,400 | Surface water | 3 | No available average above comparison levels |
| EVANSTON, CITY OF | WY5600150 | 11,727 | Surface water | 1 | No available average above comparison levels |
| FIRST FIKE SUBDIVISION | WY5600194 | 150 | Ground water | 2 | No available average above comparison levels |
| FORT WASHAKIE | 085690003 | 2,620 | Surface water | 4 | No available average above comparison levels |
| GILLETTE, CITY OF | WY5600019 | 32,222 | Ground water | 2 | No available average above comparison levels |
| GREEN RIVER, CITY OF | WY5601181 | 10,500 | Surface water purchased | 1 | No available average above comparison levels |
| GTNP-COLTER BAY VILLAGE | WY5680095 | 4,514 | Ground water | 1 | No available average above comparison levels |
| HIGH MEADOW RANCH | WY5601569 | 580 | Ground water | 1 | No available average above comparison levels |
| JACKSON, TOWN OF | WY5600213 | 24,760 | Ground water | 3 | No available average above comparison levels |
| KEMMERER-DIAMONDVILLE JPB | WY5600028 | 3,348 | Surface water | 1 | No available average above comparison levels |
| LANDER, CITY OF | WY5600176 | 7,615 | Surface water | 1 | No available average above comparison levels |
| LARAMIE, CITY OF | WY5600029 | 32,395 | Surface water | 4 | No available average above comparison levels |
| LOVELL, TOWN OF | WY5600031 | 2,250 | Surface water purchased | 1 | No available average above comparison levels |
| MILLS, TOWN OF | WY5600036 | 4,050 | Groundwater under influence of surface water | 1 | No available average above comparison levels |
| NEWCASTLE, CITY OF | WY5600256 | 3,595 | Ground water | 5 | No available average above comparison levels |
| NORTHWEST RURAL WATER DISTRICT, WY | WY5601254 | 7,330 | Surface water purchased | 1 | No available average above comparison levels |
| POWELL, CITY OF | WY5600042 | 6,310 | Surface water purchased | 1 | No available average above comparison levels |
| RAWLINS WATER SUPPLY, CITY OF | WY5600045 | 9,006 | Surface water | 1 | No available average above comparison levels |
| RIVERTON, CITY OF | WY5600047 | 10,330 | Surface water | 15 | Above an EPA comparison level |
| ROCK SPRINGS, CITY OF | WY5601182 | 24,000 | Surface water purchased | 1 | No available average above comparison levels |
| SHERIDAN WY, CITY OF | WY5600052 | 22,700 | Surface water | 2 | No available average above comparison levels |
| SOUTH CHEYENNE WATER & SEWER DISTRICT | WY5600239 | 10,000 | Surface water purchased | 1 | No available average above comparison levels |
| TORRINGTON MUNICIPAL WS | WY5600164 | 6,847 | Ground water | 2 | No available average above comparison levels |
| USAF F.E. WARREN AFB | WY5680122 | 5,500 | Surface water purchased | 1 | No available average above comparison levels |
| WARDWELL WATER & SEWER DISTRICT | WY5600067 | 4,000 | Surface water purchased | 1 | No available average above comparison levels |
| WHEATLAND, TOWN OF | WY5600187 | 3,659 | Ground water | 3 | No available average above comparison levels |
| WORLAND UTILITIES COMMISSION | WY5600197 | 4,787 | Ground water | 1 | No available average above comparison levels |
| YNP-OLD FAITHFUL | WY5680085 | 7,675 | Surface water | 1 | No available average above comparison levels |
What is included
Each active community water system with enough required samples for a yearly average 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.