PFAS in Wyoming drinking water
EPA's final UCMR 5 data covers 33 public water systems in Wyoming, serving about 408,958 people. PFAS turned up in 3 of them (9%). 1 averaged above at least one EPA limit at a sampling point, affecting about 10,330 people.
Highest PFOA and PFOS averages among systems serving 1,000 or more: City of Riverton (0.0 / 3.5 ppt).
Every tested system in Wyoming
Largest first. PFOA and PFOS columns show the average at each system's worst sampling point; EPA's limit for each is 4 ppt. Filter by name:
| Water system | People | PFOA | PFOS | PFAS found | Result |
|---|---|---|---|---|---|
| Cheyenne Board of Public Utilities · Cheyenne | 64,165 | - | - | 0 | None found |
| City of Casper · Casper | 59,000 | - | - | 0 | None found |
| City of Laramie · Laramie | 32,395 | - | - | 0 | None found |
| City of Gillette · Gillette | 32,222 | - | - | 0 | None found |
| Town of Jackson · Jackson | 24,760 | - | - | 1 | Below limits |
| City of Rock Springs · Rock Springs | 24,000 | - | - | 0 | None found |
| City of Sheridan Wy · Sheridan | 22,700 | - | - | 0 | None found |
| City of Evanston · Evanston | 11,727 | - | - | 0 | None found |
| City of Green River · Green River | 10,500 | - | - | 0 | None found |
| City of Riverton · Riverton | 10,330 | - | 3.5 | 8 | Above limit |
| City of Cody · Cody | 10,224 | - | - | 0 | None found |
| South Cheyenne Water & Sewer District · Cheyenne | 10,000 | - | - | 0 | None found |
| City of Rawlins Water Supply · Rawlins | 9,006 | - | - | 0 | None found |
| Ynp-old Faithful · Yellowstone | 7,675 | - | - | 0 | None found |
| City of Lander · Lander | 7,615 | - | - | 0 | None found |
| Northwest Rural Water District · Cody | 7,330 | - | - | 0 | None found |
| Torrington Municipal Ws · Torrington | 6,847 | - | - | 0 | None found |
| City of Douglas · Douglas | 6,400 | - | - | 1 | Below limits |
| City of Powell · Powell | 6,310 | - | - | 0 | None found |
| Usaf F.e. Warren Afb · F.e. Warren Afb | 5,500 | - | - | 0 | None found |
| Worland Utilities Commission · Worland | 4,787 | - | - | 0 | None found |
| Gtnp-colter Bay Village · Moose | 4,514 | - | - | 0 | None found |
| City of Buffalo · Buffalo | 4,419 | - | - | 0 | None found |
| Ynp-canyon Village · Yellowstone | 4,300 | - | - | 0 | None found |
| Town of Mills · Mills | 4,050 | - | - | 0 | None found |
| Wardwell Water & Sewer District · Bar Nunn | 4,000 | - | - | 0 | None found |
| Town of Wheatland · Wheatland | 3,659 | - | - | 0 | None found |
| City of Newcastle · Newcastle | 3,595 | - | - | 0 | None found |
| Kemmerer-diamondville Jpb · Kemmerer | 3,348 | - | - | 0 | None found |
| Town of Lovell · Lovell | 2,250 | - | - | 0 | None found |
| Black Thunder Coal Mine · Wright | 600 | - | - | 0 | None found |
| High Meadow Ranch · Pinedale | 580 | - | - | 0 | None found |
| First Fike Subdivision · Pavillion | 150 | - | - | 0 | None found |
On a private well in Wyoming?
EPA's program only covers public systems. Private wells are never part of UCMR 5, so the only way to know is to test. Our well testing guide covers which lab tests to order, and the best well water systems covers what to install once you have results.
Cite this page
Well & Tap. "PFAS in Wyoming drinking water: results for 33 systems." Data: U.S. EPA UCMR 5, final release August 2026. https://wellandtap.com/pfas/wyoming/
Source: EPA UCMR 5 final occurrence data (August 2026); population from EPA SDWIS. Method.