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Tap water quality report

Ronan City of

EPA monitoring tested this supplier for 74 contaminants and detected 17. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

74
contaminants tested
17
detected
2,483
people served
9
health-based violations
Montana rankingsLead in MontanaPFAS in Montana
Water source
Surface water
Ownership
Local government
Counties served
Lake

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.

9
health-based violations
256
violations on file
0
still open
ViolationTypeStatusPeriod
TT Health-based Resolved 2011-12-27
TT Health-based Resolved 2011-12-27
TT Health-based Resolved 2011-12-27
TT Health-based Resolved 2011-12-27
TT Health-based Resolved 2011-12-27
TT Health-based Resolved 2011-12-27
TT Health-based Resolved 2011-12-27
TT Health-based Resolved 2011-12-27
TT Health-based Resolved 2011-12-27
MR Monitoring Resolved 2025-04-01 → 2025-04-30

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
255 µg/L 20%
of the EPA limit 1300 µg/L
worst single sample: 390 µg/L
31/31 SYR4 2013–2019
Nitrate-Nitrite
200 µg/L 2%
of the EPA limit 10000 µg/L
 25/25 SYR4 2012–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 12/12 LCR 2025
TTHM
15.35 µg/L 19%
of the EPA limit 80 µg/L
worst single sample: 17 µg/L
12/25 SYR4 2012–2019
Chloroform
15 µg/L
No EPA limit set
worst single sample: 17 µg/L
11/25 SYR4 2012–2019
Gross Alpha, Excl. Radon And U
3.44 pCi/L 23%
of the EPA limit 15 pCi/L
worst single sample: 3.6 pCi/L
9/11 SYR4 2012–2017
Arsenic
1 µg/L 10%
of the EPA limit 10 µg/L
 8/18 SYR4 2012–2019
Nitrate
180 µg/L 1.8%
of the EPA limit 10000 µg/L
 8/10 SYR4 2013–2017
Bromodichloromethane
0.9190 µg/L
No EPA limit set
worst single sample: 1 µg/L
7/25 SYR4 2012–2019
Combined Uranium
1.7 µg/L 5.7%
of the EPA limit 30 µg/L
worst single sample: 2 µg/L
7/11 SYR4 2012–2017
Combined Radium (-226 And -228)
2.2 pCi/L 44%
of the EPA limit 5 pCi/L
worst single sample: 2.3 pCi/L
6/10 SYR4 2012–2017
Lead
16.75 µg/L 112%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
worst single sample: 21 µg/L
6/31 SYR4 2013–2019
Barium
50 µg/L 2.5%
of the EPA limit 2000 µg/L
 5/6 SYR4 2013–2017
Dichloroacetic Acid
9.72 µg/L
No EPA limit set
worst single sample: 10 µg/L
5/9 SYR4 2012–2019
Fluoride
48 µg/L 1.2%
of the EPA limit 4000 µg/L
worst single sample: 50 µg/L
5/5 SYR4 2013–2017
Total Haloacetic Acids (HAA5)
17.8 µg/L 30%
of the EPA limit 60 µg/L
worst single sample: 18 µg/L
5/9 SYR4 2012–2019
Trichloroacetic Acid
8.34 µg/L
No EPA limit set
worst single sample: 8.4 µg/L
5/9 SYR4 2012–2019
57 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-Dichloroethane1,2-Dichloropropane2,4,5-TP2,4-DAntimony, TotalAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromoformChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDibromoacetic AcidDibromochloromethaneDinosebEndrinEthylbenzeneHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNitriteOxamylPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
CITY OF RONAN
Phone
406-676-4231

Frequently asked questions about Ronan City of

Is Ronan City of tap water safe to drink?

EPA monitoring detected 17 contaminants in Ronan City of'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 Ronan City of's water?

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

How many people does Ronan City of serve?

Ronan City of reports serving 2,483 people in Montana, per its EPA record.

Has Ronan City of had any water quality violations?

The EPA has 256 violations on file for Ronan City of, of which 9 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.