Updated 2026-09-16

State water report

Montana Water Quality: 10 Cities Ranked by the Records

Name: Montana City Drinking-Water Records (2026)
Creator: PurityMap
License: https://creativecommons.org/licenses/by/4.0/

Water quality across 10 cities in Montana, drawn from EPA drinking-water records. Each city page shows the measured contaminants and a reproducible Purity Score.

Finding by finding

What Montana's records show

Counts of cities whose serving system reported each result. There is no statewide score: PurityMap does not average local records into a statewide safety verdict.

PFAS above a 2024 limit

MCL

1of 10 cities

Cities whose system reported a PFAS above its federal limit.

PFOS in Montana →

Lead detected

Action level

10of 10 cities

90th-percentile lead above zero.

Lead across Montana →

Lead above action level

Action level

0of 10 cities

No city on record above 15 µg/L.

How lead is measured →

City rankings

Montana cities ranked by the records

Highest first. A summary of each serving system’s record, not a safety verdict.

1
MissoulaMISSOULA WATER · MT0000294
Report →
2
BozemanBOZEMAN CITY OF · MT0000161
Report →
3
Butte SilverbowBUTTE SILVERBOW WATER DEPT · MT0000170
Report →
4
BelgradeBELGRADE CITY OF · MT0000136
Report →
5
WhitefishWHITEFISH CITY OF · MT0000357
Report →
6
Billings Heights DistBILLINGS HEIGHTS CO WATER DIST OF · MT0000155
Report →
7
BillingsBILLINGS CITY OF · MT0000153
Report →
8
HelenaHELENA WATER SYSTEM · MT0000241
Report →
9
Great FallsGREAT FALLS CITY OF · MT0000525
Report →
10
KalispellKALISPELL PUBLIC WORKS · MT0000259
Report →

Showing the top 10 of 10 scored cities.

See all 10 in the table

Find a Montana city

10 cities, highest Purity Score first

1Missoula
MISSOULA WATER · PWSID MT0000294 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 1 µg/LDetected
2Bozeman
BOZEMAN CITY OF · PWSID MT0000161 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 1.6 µg/LDetected
3Butte Silverbow
BUTTE SILVERBOW WATER DEPT · PWSID MT0000170 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 2 µg/LDetected
4Belgrade
BELGRADE CITY OF · PWSID MT0000136 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 1.79 µg/LDetected
5Whitefish
WHITEFISH CITY OF · PWSID MT0000357 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 2 µg/LDetected
6Billings Heights Dist
BILLINGS HEIGHTS CO WATER DIST OF · PWSID MT0000155 · Purity Score 97/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 3 µg/LDetected
7Billings
BILLINGS CITY OF · PWSID MT0000153 · Purity Score 94/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 5 µg/LDetected
8Helena
HELENA WATER SYSTEM · PWSID MT0000241 · Purity Score 94/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 3 µg/LDetected
9Great Falls
GREAT FALLS CITY OF · PWSID MT0000525 · Purity Score 84/100 (Good) · Confidence: moderate · Assessed at the water-system level
No PFAS detected; lead 12 µg/LDetected
10Kalispell
KALISPELL PUBLIC WORKS · PWSID MT0000259 · Purity Score 63/100 (Fair) · Confidence: moderate · Assessed at the water-system level
PFOS 6.6 ng/L, 1.6× the EPA limitAbove reference

End of list.

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no state score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works. See how Montana compares with other states.

By contaminant

PFAS and lead in Montana

PFAS

MCL

Highest detected PFOS result, by city.

Kalispell6.6 ng/L

| 4.0 ng/L federal MCL · 1 city above it

PFOS in Montana →PFOA in Montana What PFAS are Filters certified for PFAS

Lead

Action level

90th-percentile result, by city.

| 15 µg/L action level · none above

Lead across Montana →Filters certified for lead

Counties

Montana counties

6 counties with city reports

Suppliers

Largest water systems

BILLINGS CITY OFBillings · MT0000153 · 114,000 served
MISSOULA WATERMissoula · MT0000294 · 68,200 served
GREAT FALLS CITY OFGreat Falls · MT0000525 · 60,000 served
BOZEMAN CITY OFBozeman · MT0000161 · 56,000 served
BUTTE SILVERBOW WATER DEPTButte Silverbow · MT0000170 · 33,000 served
HELENA WATER SYSTEMHelena · MT0000241 · 32,091 served

All water systems →

Full indexAll 10 Montana city reports, A–Z

Next step

State patterns can’t tell you what reaches your tap.

Find my water

Learn

Learn your supplier

Resolve your address to the one public water system that serves it.

Find my water →

Test

Test your own tap

Plumbing inside a building can add lead and change what reaches your glass.

How to test →

Solve

Treat by concern

Only after a city report names a finding, match a treatment certified for it.

Treatment options →

Questions

Montana water, frequently asked

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How does Montana tap water compare across cities?

PurityMap ranks 10 cities in Montana by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Missoula's main water system: MISSOULA WATER · PWSID MT0000294 · Purity Score 99 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Montana cities have PFAS above the federal limit?

1 city of 10 had at least one regulated PFAS (PFOA, PFOS or PFHxS) measured above the 2024 federal limit in EPA's UCMR 5 testing, including Kalispell (PFOS 6.6 ng/L). PFAS were detected at any level in 1.

Is there lead in Montana tap water?

Utilities report lead as a 90th-percentile result from home taps. 10 of 10 Montana cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Limits, sources and corrections

A statewide page cannot tell you what reaches a specific address. Water quality varies by supplier, sampling period and household plumbing; open a city report for the evidence behind a local result.

Sources: EPA UCMR 5 (PFAS, 2024), SDWIS Lead and Copper Rule 90th-percentile results and health-based violations, and utility Consumer Confidence Reports where on file. Every city report links its dated source records.

Updated 2026-09-16. How PurityMap analyzes water data · Report an error