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Tap water quality report

Flathead County Water and Sewer

EPA monitoring tested this supplier for 99 contaminants and detected 13. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

99
contaminants tested
13
detected
7,775
people served
1
health-based violations
Montana rankingsLead in MontanaPFAS in Montana
Water source
Ground water
Ownership
Local government
Counties served
Flathead

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

1
health-based violations
17
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 1996-02-01 → 1996-02-29
MR Monitoring Resolved 2024-12-30
MR Monitoring Resolved 2024-12-30
MR Monitoring Resolved 2010-10-01
MR Monitoring Resolved 2010-10-01
MR Monitoring Resolved 2010-10-01
MR Monitoring Archived 2008-01-01 → 2016-12-31
MR Monitoring Resolved 1999-07-01
MR Monitoring Resolved 1999-07-01
MR Monitoring Resolved 1999-01-01

Other contaminants detected

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 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Copper
182 µg/L 14%
of the EPA limit 1300 µg/L
worst single sample: 260 µg/L
59/60 SYR4 2012–2018
Nitrate-Nitrite
420 µg/L 4.2%
of the EPA limit 10000 µg/L
worst single sample: 520 µg/L
31/32 SYR4 2012–2019
Nitrate
367.5 µg/L 3.7%
of the EPA limit 10000 µg/L
worst single sample: 370 µg/L
22/24 SYR4 2012–2018
Lead
0.0010 mg/L 6.7%
of the EPA limit 0.0150 mg/L
 21/21 LCR 2025
Lead
2 µg/L 13%
of the EPA limit 15 µg/L
worst single sample: 3 µg/L
21/60 SYR4 2012–2018
Barium
174 µg/L 8.7%
of the EPA limit 2000 µg/L
worst single sample: 180 µg/L
13/13 SYR4 2012–2018
Fluoride
105 µg/L 2.6%
of the EPA limit 4000 µg/L
worst single sample: 110 µg/L
11/12 SYR4 2012–2018
Combined Uranium
1.8 µg/L 6%
of the EPA limit 30 µg/L
worst single sample: 2 µg/L
9/10 SYR4 2012–2018
Combined Radium (-226 And -228)
2.12 pCi/L 42%
of the EPA limit 5 pCi/L
worst single sample: 2.2 pCi/L
5/9 SYR4 2012–2018
Gross Alpha, Excl. Radon And U
6.105 pCi/L 41%
of the EPA limit 15 pCi/L
worst single sample: 6.6 pCi/L
4/10 SYR4 2012–2018
Carbofuran
40 µg/L 100%
of the EPA limit 40 µg/L
 1/17 SYR4 2012–2018
Di(2-ethylhexyl) Phthalate
2.2 µg/L 37%
of the EPA limit 6 µg/L
 1/17 SYR4 2012–2018
Oxamyl
200 µg/L 100%
of the EPA limit 200 µg/L
 1/17 SYR4 2012–2018
86 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalArsenicAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromodichloromethaneBromoformChlorobenzeneCadmiumCarbon TetrachlorideChlordaneChloroformChromiumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDibromochloromethaneDinosebEndrinEthylbenzeneHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitritePfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTTHMTetrachloroethyleneThallium, TotalTolueneToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
JAMES, MARK D
Phone
406-257-5861

Frequently asked questions about Flathead County Water and Sewer

Is Flathead County Water and Sewer tap water safe to drink?

EPA monitoring detected 13 contaminants in Flathead County Water and Sewer's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Flathead County Water and Sewer's water?

EPA monitoring detected Copper, Nitrate-Nitrite, Nitrate, Lead, Lead, and others. The full list with the level and data source for each is above.

How many people does Flathead County Water and Sewer serve?

Flathead County Water and Sewer reports serving 7,775 people in Montana, per its EPA record.

Has Flathead County Water and Sewer had any water quality violations?

The EPA has 17 violations on file for Flathead County Water and Sewer, of which 1 is health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

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.