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Tap water quality report

Rocky Boy Agency Water

EPA monitoring tested this supplier for 82 contaminants and detected 21. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

82
contaminants tested
21
detected
1,442
people served
15
health-based violations
Montana rankingsLead in MontanaPFAS in Montana
Water source
Ground water
Ownership
Native American

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.

15
health-based violations
129
violations on file
0
still open
ViolationTypeStatusPeriod
TT Health-based Resolved 2015-07-25
MCL Health-based Resolved 2005-12-01 → 2005-12-31
MCL Health-based Resolved 2005-12-01 → 2005-12-31
MCL Health-based Resolved 2005-12-01 → 2005-12-31
MCL Health-based Resolved 2005-12-01 → 2005-12-31
MCL Health-based Resolved 2005-12-01 → 2005-12-31
MCL Health-based Resolved 2005-06-01 → 2005-06-30
MCL Health-based Resolved 2005-06-01 → 2005-06-30
MCL Health-based Resolved 2005-06-01 → 2005-06-30
MCL Health-based Resolved 2005-06-01 → 2005-06-30

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
Nitrate-Nitrite
662 µg/L 6.6%
of the EPA limit 10000 µg/L
worst single sample: 690 µg/L
39/40 SYR4 2012–2019
Copper
329.55 µg/L 25%
of the EPA limit 1300 µg/L
worst single sample: 692 µg/L
30/30 SYR4 2013–2017
Lead
0.0020 mg/L 13%
of the EPA limit 0.0150 mg/L
 17/17 LCR 2026
Combined Uranium
5 µg/L 17%
of the EPA limit 30 µg/L
 11/11 SYR4 2013
Fluoride
200 µg/L 5%
of the EPA limit 4000 µg/L
 7/7 SYR4 2013–2019
Gross Alpha, Excl. Radon And U
5.75 pCi/L 38%
of the EPA limit 15 pCi/L
worst single sample: 6 pCi/L
6/6 SYR4 2013
TTHM
20.7 µg/L 26%
of the EPA limit 80 µg/L
worst single sample: 26 µg/L
6/18 SYR4 2013–2019
Chloroform
16.74 µg/L
No EPA limit set
worst single sample: 20 µg/L
5/16 SYR4 2013–2019
Lead
2 µg/L 13%
of the EPA limit 15 µg/L
 5/30 SYR4 2013–2017
Combined Radium (-226 And -228)
1.2 pCi/L 24%
of the EPA limit 5 pCi/L
 4/6 SYR4 2013
Total Haloacetic Acids (HAA5)
18.071 µg/L 30%
of the EPA limit 60 µg/L
worst single sample: 20 µg/L
3/10 SYR4 2013–2018
Bromodichloromethane
5.08 µg/L
No EPA limit set
worst single sample: 5.3 µg/L
2/16 SYR4 2013–2019
Nitrate
250 µg/L 2.5%
of the EPA limit 10000 µg/L
 2/2 SYR4 2016
Trichloroacetic Acid
8.7755 µg/L
No EPA limit set
worst single sample: 9.2 µg/L
2/8 SYR4 2013–2018
Arsenic
2 µg/L 20%
of the EPA limit 10 µg/L
 1/7 SYR4 2013–2019
Asbestos
0.2000 MFL 2.9%
of the EPA limit 7 MFL
 1/1 SYR4 2015
Barium
80 µg/L 4%
of the EPA limit 2000 µg/L
 1/7 SYR4 2013–2019
Dibromochloromethane
0.9600 µg/L
No EPA limit set
 1/16 SYR4 2013–2019
Dichloroacetic Acid
11 µg/L
No EPA limit set
 1/8 SYR4 2013–2018
Toluene
2.4 µg/L 0.2%
of the EPA limit 1000 µg/L
 1/9 SYR4 2013–2019
Xylenes, Total
1.1 µg/L 0%
of the EPA limit 10000 µg/L
 1/9 SYR4 2013–2019
61 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane2,4,5-TP2,4-DAntimony, TotalAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromoformChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDibromoacetic AcidDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNitriteOxamylPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl Chloridecis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
NAULT, TIM
Phone
406-301-1852
Email
[email protected]

Frequently asked questions about Rocky Boy Agency Water

Is Rocky Boy Agency Water tap water safe to drink?

EPA monitoring detected 21 contaminants in Rocky Boy Agency Water'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 Rocky Boy Agency Water's water?

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

How many people does Rocky Boy Agency Water serve?

Rocky Boy Agency Water reports serving 1,442 people in Montana, per its EPA record.

Has Rocky Boy Agency Water had any water quality violations?

The EPA has 129 violations on file for Rocky Boy Agency Water, of which 15 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.