Montana Water Quality Report 2026
Montana tap water is safe to drink based on our analysis of 5 water systems serving 335,657 residents. The average PurityMap score is 85.0/100 (Grade: A), which is 7.1 points above the national average.
- No major contaminant flags across Montana cities. All cities meet EPA federal drinking water standards.
Montana water is generally good quality. A carbon pitcher or faucet filter removes chlorine taste and provides extra protection. No major filtration investment is needed for most residents.
Moderate
Montana is 7.1 points above the US average of 77.9/100. Hardness is 1.7 GPG below the US average of 6.3 GPG.
All 5 cities score similarly
How Montana's 5 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 |
|---|---|---|---|---|
| Billings | 117K | 85/100 | 6.5 GPG | — |
| Missoula | 74K | 85/100 | 3.2 GPG | — |
| Great Falls | 59K | 85/100 | 5.8 GPG | — |
| Bozeman | 53K | 85/100 | 3.0 GPG | — |
| Helena | 32K | 85/100 | 4.5 GPG | — |
Montana generally has soft to moderate water. Average: 4.6 GPG (Moderate). Most residents do not need a softener.
Based on EPA UCMR5 data, PFAS have not been detected above advisory levels in any Montana cities in our database as of 2026.
All Montana cities have lead below 5 ppb. Average: 1.1 ppb. Individual homes with older plumbing may have higher levels.
Where Montana gets its drinking water, based on 5 water systems.
| Source Type | Cities | % of Total |
|---|---|---|
| Surface Water | 5 | 100% |
Montana water is generally good. A carbon pitcher filter improves taste.
| # | City | Pop. | Score | Hardness | Lead | PFAS | TDS |
|---|---|---|---|---|---|---|---|
| 1 | Billings | 117K | 85/100 | 6.5 GPG (Moderate) | 1.2 ppb | ✅ No | 225 ppm |
| 2 | Missoula | 74K | 85/100 | 3.2 GPG (Soft) | 0.8 ppb | ✅ No | 95 ppm |
| 3 | Great Falls | 59K | 85/100 | 5.8 GPG (Moderate) | 1.5 ppb | ✅ No | 200 ppm |
| 4 | Helena | 32K | 85/100 | 4.5 GPG (Moderate) | 1.0 ppb | ✅ No | 155 ppm |
| 5 | Bozeman | 53K | 85/100 | 3.0 GPG (Soft) | 0.8 ppb | ✅ No | 90 ppm |
Montana has 5 utilities. Major: City of Billings Water Division, City of Missoula Water, City of Great Falls Water, City of Helena Water Division, City of Bozeman Water.
Sources: Yellowstone River, Rattlesnake Creek and Clark Fork River, Missouri River, Missouri River and Tenmile Creek, Hyalite Creek and Sourdough Creek.
- 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.
5 city water quality reports available for Montana.
Bozeman Water Quality Report
Great Falls Water Quality Report
Helena Water Quality Report
Missoula Water Quality Report
Compare water quality reports across all 50 US states