Is Butte, MT tap water safe?
Data: U.S. EPA · How we read the data · How we check it
Summary
No federal limits exceeded in EPA data for Butte Silverbow Water Dept.
Butte Silverbow Water Dept supplies Butte (33,000 people).
Water system
Butte Silverbow Water Dept
33,000 people · Surface water · EPA ID MT0000170
| PFAS | Highest average | Limit |
|---|---|---|
| PFOA Not detected | – | 4 ppt |
| PFOS Not detected | – | 4 ppt |
| PFHxS Not detected | – | 10 ppt |
| PFNA Not detected | – | 10 ppt |
| HFPO-DA (GenX) Not detected | – | 10 ppt |
ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.
Lead: 2 ppb at the 90th percentile (Dec 2024, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0
Across Montana, 0 of 40 water systems EPA tested had PFAS above a 2024 federal limit, and 6 systems were above the lead action level in results from the last five years. Montana results.
Butte homes and lead pipes
Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. How to check your own line.
Housing: Census American Community Survey 2020–2024 5-year estimates for Butte-Silver Bow (balance) (tables B25034, B25003). Estimates for small places have a margin of error.
How nearby cities compare
| City | PFAS | Lead (90th pct.) |
|---|---|---|
| Helena 57 mi Helena Water System | None above limits | 3 ppb |
| Bozeman 79 mi City of Bozeman | None above limits | 1.6 ppb |
| Missoula 94 mi Missoula Water | None above limits | 2 ppb |
| Great Falls 129 mi City of Great Falls | None above limits | 12 ppb |
| Kalispell 179 mi Kalispell Public Works | None above limits | 2 ppb |
| Billings 197 mi City of Billings | None above limits | 3 ppb |
Butte ZIP codes (3)
- 59701
- 59727
- 59748
Questions
Is Butte tap water safe to drink?
Butte Silverbow Water Dept has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.
Who supplies water in Butte, MT?
Butte Silverbow Water Dept, which serves 33,000 people.
Does Butte tap water have PFAS?
None detected above EPA's reporting limits. Butte Silverbow Water Dept had no PFAS detected in EPA's 2023–2025 testing. "Not detected" means below the reporting limit (about 2 to 20 ppt), not proven zero.
Do Butte homes have lead pipes?
Census estimates put 74% of Butte homes as built before 1980 (Montana: 49%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Butte Silverbow Water Dept's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.