Latest water news in Wyoming
Recent reporting on Wyoming drinking water — boil-water advisories, regulatory action, and infrastructure events.
Congress Demands Answers From Meta Over Cheyenne Water Contamination
Rep. Harriet Hageman has written to Mark Zuckerberg demanding answers on the bacterium Meta's contractor discharged into Cheyenne's reuse water system.
Read full story →Data Centers Are Fouling Local Water Systems in Wyoming and Georgia
A Meta contractor contaminated Cheyenne's reuse water with bacteria; a Georgia data center left nearby wells running brown. Two incidents, one pattern.
Read full story →Wyoming water quality overview
Wyoming's drinking water quality is fair overall, with an average score of 69.7 out of 100 across 63 cities tested. The median score is 73.6, serving a total population of 496,341 residents. The state shows a mixed picture: 19 cities earned an A, while 9 cities received an F. PFAS "forever chemicals" were detected in 15 of 63 cities tested (24%). 2 cities exceed the 2024 EPA maximum contaminant levels. 1 city has lead levels exceeding the EPA action level of 15 ppb, often indicating aging infrastructure with lead service lines or lead solder. The state relies on a mix of water sources: 36 cities use groundwater while 27 draw from surface water such as rivers, lakes, and reservoirs.
Issues to watch in Wyoming
Explore contaminants in Wyoming
More contaminants tested in Wyoming
Private-well water in Wyoming
Based on USGS Powell Domestic-Well Database — 1,375 private wells sampled across Wyoming. These wells are not regulated by the EPA; if you draw your tap from a private well, the public-system grade above does not apply to you.
Top industrial water polluters in Wyoming
Industrial polluters nearby
The 10 facilities reporting the most pounds released to surface water in Wyoming, 2023.
Total reported releases to surface water: 1,990 lbs
| Facility | Top chemical | To surface water (lbs/yr) |
|---|---|---|
PACIFICORP NAUGHTON PLANT KEMMERER, WY83101 | Barium And Barium Compounds | 993 |
WYOMING REFINING CO NEWCASTLE, WY82701 | Ammonia | 571 |
PACIFICORP DAVE JOHNSTON PLANT GLENROCK, WY82637 | Copper And Copper Compounds | 162 |
NELSON BROTHERS MINING SERVICES LLC GILLETTE, WY82717 | Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 118 |
WESTERN SUGAR COOPERATIVE LOVELL FACTORY LOVELL, WY82431 | Ammonia | 107 |
+ 1 more facility
Source: EPA Toxic Release Inventory (TRI) 2023
How Wyoming cities scored
Best Cities
Worst Cities
Water quality across Wyoming
Each dot is a city, colored by its water quality grade. Size reflects population served. Click any city to view its full water report.
63 cities in Wyoming
| # | City | Grade | Score | Population | Violations |
|---|---|---|---|---|---|
| 1 | Wright | A+ | 95 | 3K | 8 |
| 2 | Powell | A | 93.6 | 6K | 3 |
| 3 | Teton Village | A | 93.4 | 906 | 11 |
| 4 | Upton | A | 90.5 | 1K | 7 |
| 5 | Ranchester | A | 90.2 | 1K | 9 |
| 6 | Byron | A- | 89.8 | 593 | 8 |
| 7 | Worland | A- | 89.4 | 7K | 23 |
| 8 | Hanna | A- | 89.4 | 841 | 22 |
| 9 | Dayton | A- | 88.9 | 824 | 52 |
| 10 | Glenrock | A- | 88.8 | 2K | 8 |
| 11 | Guernsey | A- | 88.8 | 1K | 80 |
| 12 | Moose | A- | 88.3 | 7K | 8 |
| 13 | Shoshoni | A- | 88.1 | 515 | 41 |
| 14 | Lyman | A- | 87.9 | 2K | 51 |
| 15 | Mountain View | A- | 87.8 | 1K | 18 |
| 16 | Sundance | A- | 87.7 | 1K | 36 |
| 17 | Wamsutter | A- | 87 | 500 | 22 |
| 18 | Cowley | A- | 86.5 | 800 | 46 |
| 19 | Smoot | A- | 85.3 | 720 | 32 |
| 20 | Basin | B+ | 84.3 | 1K | 20 |
| 21 | Lander | B+ | 84.2 | 8K | 89 |
| 22 | Evanston | B+ | 81.3 | 12K | 44 |
| 23 | Moorcroft | B+ | 80.9 | 1K | 23 |
| 24 | Pinedale | B+ | 80.6 | 2K | 72 |
| 25 | Encampment | B+ | 80.2 | 580 | 158 |
| 26 | Star Valley Ranch | B | 78.6 | 2K | 54 |
| 27 | Green River | B | 77.5 | 11K | 40 |
| 28 | Saratoga | B | 77.3 | 2K | 48 |
| 29 | Greybull | B | 77 | 3K | 95 |
| 30 | Lovell | B | 76 | 3K | 44 |
| 31 | Ethete | B- | 74.5 | 3K | 358 |
| 32 | Bedford | B- | 73.6 | 750 | 51 |
| 33 | Burns | B- | 73.3 | 1K | 131 |
| 34 | Buffalo | B- | 73.2 | 4K | 65 |
| 35 | Cody | B- | 72 | 18K | 67 |
| 36 | Farson | B- | 72 | 530 | 112 |
| 37 | Lusk | C+ | 69.9 | 2K | 119 |
| 38 | Little America | C+ | 68.7 | 2K | 67 |
| 39 | Wheatland | C+ | 66.7 | 4K | 156 |
| 40 | Rock Springs | C | 64.8 | 30K | 132 |
| 41 | Douglas | C | 64.2 | 7K | 95 |
| 42 | Dubois | C | 63.5 | 2K | 168 |
| 43 | Yellowstone Nt | C | 62.1 | 6K | 38 |
| 44 | Rawlins | C- | 56 | 9K | 59 |
| 45 | Laramie | C- | 55.2 | 34K | 120 |
| 46 | Marbleton | D+ | 52 | 861 | 912 |
| 47 | Alpine | D+ | 51.1 | 2K | 213 |
| 48 | Kemmerer | D+ | 50.8 | 3K | 58 |
| 49 | Yellowstone Np | D | 50 | 8K | 32 |
| 50 | Afton | D+ | 50 | 2K | 391 |
| 51 | Cokeville | D+ | 50 | 535 | 135 |
| 52 | Wilson | D | 48 | 536 | 231 |
| 53 | Newcastle | D | 47 | 5K | 350 |
| 54 | Thermopolis | D | 45.6 | 4K | 130 |
| 55 | Gillette | F | 44.5 | 45K | 1227 |
| 56 | Jackson | F | 43.2 | 27K | 1633 |
| 57 | Casper | F | 41.8 | 62K | 267 |
| 58 | Fort Washakie | F | 41.8 | 6K | 510 |
| 59 | Mills | F | 41.8 | 4K | 288 |
| 60 | Sheridan | F | 41.5 | 24K | 235 |
| 61 | Riverton | F | 38.7 | 11K | 730 |
| 62 | Torrington | F | 36.2 | 8K | 211 |
| 63 | Cheyenne | F | 30.8 | 78K | 515 |
Browse Wyoming by ZIP code
Look up water quality by ZIP code to find the systems serving your area.
View all Wyoming ZIP codes →Frequently asked questions about Wyoming's water
Is Wyoming's tap water safe to drink?
Wyoming's water quality varies by city. The statewide average grade is C+ (69.7/100). 57% of cities scored an A or B, while 29% received a D or F. Check your specific city for detailed results.
Which Wyoming cities have the best water quality?
The top-rated cities are Wright (A+), Powell (A), Teton Village (A). These cities scored highest based on violation history, lead levels, PFAS contamination, and regulatory compliance.
Which Wyoming cities have the worst water quality?
The lowest-rated cities are Cheyenne (F), Torrington (F), Riverton (F). We recommend residents in these areas consider water filtration and review their city's specific contaminant data.
How many Wyoming cities have PFAS in their water?
15 out of 63 cities tested positive for PFAS "forever chemicals" (24%). 2 cities exceed the 2024 EPA maximum contaminant levels. Reverse osmosis or activated carbon filters can help reduce PFAS exposure.
Do any Wyoming cities have dangerous lead levels?
1 city exceeds the EPA lead action level of 15 ppb. Lead contamination typically comes from aging pipes and lead service lines rather than the water source itself. An NSF 53-certified filter can effectively remove lead from tap water.