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Tap water quality report

Butte, MT

EPA monitoring detected 17 contaminants across the 1 water supplier serving Butte. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

1
water supplier
33,000
people served
17
contaminants found
Montana rankings Lead in Montana PFAS in Montana

What was found in Butte's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Copper
968 µg/L 74%
of the EPA limit 1300 µg/L
 1/1 SYR4
Fluoride
146 µg/L 3.7%
of the EPA limit 4000 µg/L
 1/1 SYR4
Nitrate-Nitrite
130 µg/L 1.3%
of the EPA limit 10000 µg/L
 1/1 SYR4
Lead
72 µg/L 480%
of the EPA limit, in the worst sample — 15 µg/L
 1/1 SYR4
Total Haloacetic Acids (HAA5)
71 µg/L 118%
of the EPA limit, in the worst sample — 60 µg/L
 1/1 SYR4
TTHM
60 µg/L 75%
of the EPA limit 80 µg/L
 1/1 SYR4
Chloroform
58 µg/L
No EPA limit set
 1/1 SYR4
Trichloroacetic Acid
42 µg/L
No EPA limit set
 1/1 SYR4
Dichloroacetic Acid
28 µg/L
No EPA limit set
 1/1 SYR4
Bromodichloromethane
5.1 µg/L
No EPA limit set
 1/1 SYR4
Monochloroacetic Acid
3.4 µg/L
No EPA limit set
 1/1 SYR4
Arsenic
2 µg/L 20%
of the EPA limit 10 µg/L
 1/1 SYR4
Selenium
2 µg/L 4%
of the EPA limit 50 µg/L
 1/1 SYR4
Gross Alpha, Excl. Radon And U
1.4 pCi/L 9.3%
of the EPA limit 15 pCi/L
 1/1 SYR4
Tetrachloroethylene
0.7500 µg/L 15%
of the EPA limit 5 µg/L
 1/1 SYR4
Dibromoacetic Acid
0.4900 µg/L
No EPA limit set
 1/1 SYR4
Lead
0.0020 mg/L 13%
of the EPA limit 0.0150 mg/L
 1/1 LCR
Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Butte

SupplierPopulation served
BUTTE SILVERBOW WATER DEPT 33,000

Frequently asked questions about Butte tap water

Is Butte tap water safe to drink?

EPA testing detected 17 contaminants in the water serving Butte. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Butte?

1 public water supplier report drinking-water monitoring for Butte, Montana to the EPA. Each is listed above with its population served.

What contaminants are in Butte's water?

The contaminants EPA monitoring detected in Butte include Copper, Fluoride, Nitrate-Nitrite, Lead, Total Haloacetic Acids (HAA5). The full list, with the highest level found and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.