Flathead County Water Quality: 2 Cities Ranked by the Records
Flathead County, Montana: 2 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.
Highest result for each contaminant
One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.
Perfluorooctanesulfonic acid (PFOS)Detected in 1 system of 2 tested4.0 ng/L federal MCL (2024) · US EPAHighest6.6 ng/L
- KALISPELL PUBLIC WORKS6.6 ng/LSample date: 2023-01-30 to 2023-07-18
- WHITEFISH CITY OFNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-01-23 to 2023-12-19
Perfluorohexanesulfonic acid (PFHxS)Detected in 1 system of 2 tested10 ng/L federal MCL (2024) · US EPAHighest5 ng/L
- KALISPELL PUBLIC WORKS5 ng/LSample date: 2023-01-30 to 2023-07-18
- WHITEFISH CITY OFNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-01-23 to 2023-12-19
Lead (90th percentile)Detected in 2 systems15 µg/L federal action level · US EPAHighest2 µg/L
- KALISPELL PUBLIC WORKS2 µg/LMonitoring period: 2021–2023
- WHITEFISH CITY OF2 µg/LMonitoring period: 2023–2025
28 substances tested, none detected in any systemShow
Tested in these 2 systems: KALISPELL PUBLIC WORKS, WHITEFISH CITY OF
- 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
- 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
- 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
- 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
- 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
- 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
- Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
- Lithium
- N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
- N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
- Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
- Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
- Perfluoro-3-methoxypropanoic acid (PFMPA)
- Perfluoro-4-methoxybutanoic acid (PFMBA)
- Perfluorobutanesulfonic acid (PFBS)
- Perfluorobutanoic acid (PFBA)
- Perfluorodecanoic acid (PFDA)
- Perfluorododecanoic acid (PFDoA)
- Perfluoroheptanesulfonic acid (PFHpS)
- Perfluoroheptanoic acid (PFHpA)
- Perfluorohexanoic acid (PFHxA)
- Perfluorononanoic acid (PFNA)
- Perfluorooctanoic acid (PFOA)
- Perfluoropentanesulfonic acid (PFPeS)
- Perfluoropentanoic acid (PFPeA)
- Perfluorotetradecanoic acid (PFTA)
- Perfluorotridecanoic acid (PFTrDA)
- Perfluoroundecanoic acid (PFUnA)
Cities ranked by the records
Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county 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.
0of 2 cities above the 15 µg/L action level
Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.
Lead in MontanaLargest water systems
Frequently asked
How does Flathead County tap water compare across cities?
PurityMap ranks 2 cities in Flathead County 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 Whitefish's main water system: WHITEFISH CITY OF · PWSID MT0000357 · Purity Score 98 (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 Flathead County cities had a PFAS sample above a 2024 EPA limit?
1 of 2 Flathead County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Kalispell (PFOS 6.6 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 1.
Is there lead in Flathead County tap water?
Utilities report lead as a 90th-percentile result from home taps. 2 of 2 Flathead County 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.
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