Wyoming Water Quality Report 2026
Wyoming tap water is safe — softener may help based on our analysis of 6 water systems serving 231,844 residents. The average PurityMap score is 84.3/100 (Grade: B), which is 6.4 points above the national average.
- 1 cities (17%) have hard or very hard water (7+ GPG) which causes scale buildup and appliance damage.
A water softener is the most impactful investment for Wyoming residents in hard water areas. A basic carbon pitcher or faucet filter removes chlorine and improves taste.
Moderate
Wyoming is 6.4 points above the US average of 77.9/100. Hardness is 1.0 GPG below the US average of 6.3 GPG.
Cities ranked by lowest score. Click any city for the full report and filter recommendations.
| Rank | City | Score | Hardness | Lead | Key Issues |
|---|---|---|---|---|---|
| 1 | Gillette | 81/100 | 8.5 GPG | 1.2 ppb | Hard (8.5 GPG) |
| 2 | Cheyenne | 85/100 | 4.5 GPG | 1.2 ppb | Hardness 4.5 GPG |
| 3 | Casper | 85/100 | 5.2 GPG | 1.5 ppb | Hardness 5.2 GPG |
| 4 | Laramie | 85/100 | 3.8 GPG | 1.0 ppb | Hardness 3.8 GPG |
| 5 | Rock Springs | 85/100 | 6.0 GPG | 1.5 ppb | Hardness 6.0 GPG, TDS 215 ppm |
| 6 | Sheridan | 85/100 | 4.0 GPG | 1.0 ppb | Hardness 4.0 GPG |
How Wyoming's 6 cities score on the PurityMap 0–100 scale:
Water quality for the most populated cities. Click any city for details.
| City | Population | Score | Hardness | Key Issues |
|---|---|---|---|---|
| Cheyenne | 65K | 85/100 | 4.5 GPG | — |
| Casper | 60K | 85/100 | 5.2 GPG | — |
| Gillette | 33K | 81/100 | 8.5 GPG | Hard |
| Laramie | 33K | 85/100 | 3.8 GPG | — |
| Rock Springs | 23K | 85/100 | 6.0 GPG | — |
| Sheridan | 18K | 85/100 | 4.0 GPG | — |
1 of 6 cities (17%) in Wyoming have hard or very hard water (7+ GPG). Gillette has the hardest at 8.5 GPG. Cities: Gillette. A water softener is recommended.
Based on EPA UCMR5 data, PFAS have not been detected above advisory levels in any Wyoming cities in our database as of 2026.
All Wyoming cities have lead below 5 ppb. Average: 1.2 ppb. Individual homes with older plumbing may have higher levels.
Where Wyoming gets its drinking water, based on 6 water systems.
| Source Type | Cities | % of Total |
|---|---|---|
| Surface Water | 4 | 67% |
| Mixed (Ground + Surface) | 2 | 33% |
Wyoming water is generally good. A carbon pitcher filter improves taste.
| # | City | Pop. | Score | Hardness | Lead | PFAS | TDS |
|---|---|---|---|---|---|---|---|
| 1 | Gillette | 33K | 81/100 | 8.5 GPG (Hard) | 1.2 ppb | ✅ No | 340 ppm |
| 2 | Cheyenne | 65K | 85/100 | 4.5 GPG (Moderate) | 1.2 ppb | ✅ No | 155 ppm |
| 3 | Casper | 60K | 85/100 | 5.2 GPG (Moderate) | 1.5 ppb | ✅ No | 180 ppm |
| 4 | Laramie | 33K | 85/100 | 3.8 GPG (Moderate) | 1.0 ppb | ✅ No | 130 ppm |
| 5 | Rock Springs | 23K | 85/100 | 6.0 GPG (Moderate) | 1.5 ppb | ✅ No | 215 ppm |
| 6 | Sheridan | 18K | 85/100 | 4.0 GPG (Moderate) | 1.0 ppb | ✅ No | 140 ppm |
Wyoming has 6 utilities. Major: City of Cheyenne Board of Public Utilities, City of Casper Utilities, City of Laramie Utilities, City of Gillette Water, City of Rock Springs Water.
Sources: Crow Creek reservoirs and groundwater, North Platte River, Laramie River and Pioneer Canal, Keyhole Reservoir and groundwater, Green River.
- EPA Safe Drinking Water Information System
- EWG Tap Water Database
- State utility Consumer Confidence Reports
- USGS regional water monitoring data
PurityMap compiles publicly available data and does not perform independent testing.
6 city water quality reports available for Wyoming.
Cheyenne Water Quality Report
Gillette Water Quality Report
Laramie Water Quality Report
Rock Springs Water Quality Report
Sheridan Water Quality Report
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