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Tap water quality report

River Rock County Water and Sewer Dist

EPA monitoring tested this supplier for 105 contaminants and detected 13. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

105
contaminants tested
13
detected
4,200
people served
28
health-based violations
Montana rankingsLead in MontanaPFAS in Montana
Water source
Ground water
Ownership
Private
Counties served
Gallatin

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.

28
health-based violations
174
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 2008-06-01 → 2008-06-30
MCL Health-based Resolved 2008-06-01 → 2008-06-30
MCL Health-based Resolved 2008-06-01 → 2008-06-30
MCL Health-based Resolved 2008-06-01 → 2008-06-30
MCL Health-based Resolved 2008-06-01 → 2008-06-30
MCL Health-based Resolved 2005-09-01 → 2005-09-30
MCL Health-based Resolved 2005-09-01 → 2005-09-30
MCL Health-based Resolved 2005-09-01 → 2005-09-30
MCL Health-based Resolved 2005-09-01 → 2005-09-30
MCL Health-based Resolved 2005-09-01 → 2005-09-30

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
231.4 µg/L 18%
of the EPA limit 1300 µg/L
worst single sample: 321 µg/L
79/81 SYR4 2013–2018
Lead
5.84 µg/L 39%
of the EPA limit 15 µg/L
worst single sample: 15 µg/L
74/81 SYR4 2013–2018
Nitrate-Nitrite
2069 µg/L 21%
of the EPA limit 10000 µg/L
worst single sample: 2070 µg/L
22/22 SYR4 2012–2019
Lead
0.0028 mg/L 19%
of the EPA limit 0.0150 mg/L
 20/20 LCR 2027
Fluoride
254.4 µg/L 6.4%
of the EPA limit 4000 µg/L
worst single sample: 256 µg/L
3/3 SYR4 2013–2019
Barium
100 µg/L 5%
of the EPA limit 2000 µg/L
 2/2 SYR4 2013–2015
Chloroform
24.0665 µg/L
No EPA limit set
worst single sample: 25.3 µg/L
2/5 SYR4 2013–2018
TTHM
27.675 µg/L 35%
of the EPA limit 80 µg/L
worst single sample: 28.8 µg/L
2/5 SYR4 2013–2018
Bromodichloromethane
3.5 µg/L
No EPA limit set
 1/5 SYR4 2013–2018
Bromoform
2.2 µg/L
No EPA limit set
 1/5 SYR4 2013–2018
Combined Uranium
2 µg/L 6.7%
of the EPA limit 30 µg/L
 1/1 SYR4 2015
Dibromochloromethane
2.6 µg/L
No EPA limit set
 1/5 SYR4 2013–2018
Gross Alpha, Excl. Radon And U
2.1 pCi/L 14%
of the EPA limit 15 pCi/L
 1/1 SYR4 2015
92 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalArsenicAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumCombined Radium (-226 And -228)DichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDibromoacetic AcidDichloroacetic AcidDinosebEthylene DibromideEndrinEthylbenzeneHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNetfosaaNfdhaNmefosaaOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Haloacetic Acids (HAA5)Total Polychlorinated Biphenyls (PCB)ToxapheneTrichloroacetic AcidTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
CLARKSON, CHRISTINE
Phone
406-581-7644

Frequently asked questions about River Rock County Water and Sewer Dist

Is River Rock County Water and Sewer Dist tap water safe to drink?

EPA monitoring detected 13 contaminants in River Rock County Water and Sewer Dist'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 River Rock County Water and Sewer Dist's water?

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

How many people does River Rock County Water and Sewer Dist serve?

River Rock County Water and Sewer Dist reports serving 4,200 people in Montana, per its EPA record.

Has River Rock County Water and Sewer Dist had any water quality violations?

The EPA has 174 violations on file for River Rock County Water and Sewer Dist, of which 28 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.