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Tap water quality report

Big Sky County Water and Sewer Dist 363

EPA monitoring tested this supplier for 97 contaminants and detected 13. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

97
contaminants tested
13
detected
4,132
people served
24
health-based violations
Montana rankingsLead in MontanaPFAS in Montana
Water source
Ground water
Ownership
Local government
Counties served
Madison

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.

24
health-based violations
97
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 2012-01-01 → 2012-01-31
MCL Health-based Resolved 2012-01-01 → 2012-01-31
MCL Health-based Resolved 2012-01-01 → 2012-01-31
MCL Health-based Resolved 2012-01-01 → 2012-01-31
MCL Health-based Resolved 2008-09-01 → 2008-09-30
MCL Health-based Resolved 2008-09-01 → 2008-09-30
MCL Health-based Resolved 2008-09-01 → 2008-09-30
MCL Health-based Resolved 2008-09-01 → 2008-09-30
MCL Health-based Resolved 2008-09-01 → 2008-09-30
MCL Health-based Resolved 2005-08-01 → 2005-08-31

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
PFBS 0.0031 µg/L 1/4 2025

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
Nitrate-Nitrite
3045 µg/L 30%
of the EPA limit 10000 µg/L
worst single sample: 5250 µg/L
68/82 SYR4 2012–2019
Copper
186.75 µg/L 14%
of the EPA limit 1300 µg/L
worst single sample: 352 µg/L
58/61 SYR4 2013–2019
Lead
10.95 µg/L 73%
of the EPA limit 15 µg/L
worst single sample: 137 µg/L
28/61 SYR4 2013–2019
Lead
0.0048 mg/L 32%
of the EPA limit 0.0150 mg/L
 20/20 LCR 2025
Arsenic
18.45 µg/L 185%
of the EPA limit, at the 95th percentile of samples — 10 µg/L
worst single sample: 23 µg/L
8/15 SYR4 2013–2019
Fluoride
680 µg/L 17%
of the EPA limit 4000 µg/L
worst single sample: 800 µg/L
7/8 SYR4 2013–2019
Gross Alpha, Excl. Radon And U
6.1 pCi/L 41%
of the EPA limit 15 pCi/L
worst single sample: 6.4 pCi/L
5/5 SYR4 2013
Barium
205 µg/L 10%
of the EPA limit 2000 µg/L
worst single sample: 210 µg/L
3/8 SYR4 2013–2019
Antimony, Total
2.95 µg/L 49%
of the EPA limit 6 µg/L
worst single sample: 3 µg/L
2/14 SYR4 2013–2019
Combined Uranium
1 µg/L 3.3%
of the EPA limit 30 µg/L
 1/5 SYR4 2013
Selenium
2 µg/L 4%
of the EPA limit 50 µg/L
 1/8 SYR4 2013–2019
Xylenes, Total
1.1 µg/L 0%
of the EPA limit 10000 µg/L
 1/16 SYR4 2013–2019
84 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-PF3ONSAdonaAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromodichloromethaneBromoformChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneChloroformChromiumCombined Radium (-226 And -228)DichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDibromochloromethaneDinosebEndrinEthylbenzeneHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaOxamylPfbaPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSimazineStyreneTTHMTetrachloroethyleneThallium, TotalTolueneToxapheneTrichloroethyleneVinyl Chloridecis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
SAND, AMY
Phone
406-995-2660
Email
[email protected]

Frequently asked questions about Big Sky County Water and Sewer Dist 363

Is Big Sky County Water and Sewer Dist 363 tap water safe to drink?

EPA monitoring detected 13 contaminants in Big Sky County Water and Sewer Dist 363'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 Big Sky County Water and Sewer Dist 363's water?

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

How many people does Big Sky County Water and Sewer Dist 363 serve?

Big Sky County Water and Sewer Dist 363 reports serving 4,132 people in Montana, per its EPA record.

Has Big Sky County Water and Sewer Dist 363 had any water quality violations?

The EPA has 97 violations on file for Big Sky County Water and Sewer Dist 363, of which 24 are 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.