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Tap water quality report

Mission Dam Water

EPA monitoring tested this supplier for 82 contaminants and detected 11. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

82
contaminants tested
11
detected
87
people served
29
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.

29
health-based violations
52
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 2015-04-01 → 2015-04-30
MCL Health-based Resolved 2015-04-01 → 2015-04-30
MCL Health-based Resolved 2015-01-01 → 2015-01-31
MCL Health-based Resolved 2015-01-01 → 2015-01-31
MCL Health-based Resolved 2014-08-01 → 2014-08-31
MCL Health-based Resolved 2014-08-01 → 2014-08-31
MCL Health-based Resolved 2014-07-01 → 2014-07-31
MCL Health-based Resolved 2014-07-01 → 2014-07-31
MCL Health-based Resolved 2005-12-01 → 2005-12-31
MCL Health-based Resolved 2005-12-01 → 2005-12-31

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
70 µg/L 5.4%
of the EPA limit 1300 µg/L
worst single sample: 100 µg/L
16/20 SYR4 2017–2019
Lead
0.0020 mg/L 13%
of the EPA limit 0.0150 mg/L
 14/14 LCR 2025
Nitrate-Nitrite
282 µg/L 2.8%
of the EPA limit 10000 µg/L
worst single sample: 290 µg/L
9/13 SYR4 2012–2019
Lead
5.75 µg/L 38%
of the EPA limit 15 µg/L
worst single sample: 6 µg/L
6/20 SYR4 2017–2019
Nitrate
290 µg/L 2.9%
of the EPA limit 10000 µg/L
 6/6 SYR4 2016–2018
Combined Uranium
2.16 µg/L 7.2%
of the EPA limit 30 µg/L
worst single sample: 2.2 µg/L
5/5 SYR4 2013–2019
Fluoride
1190 µg/L 30%
of the EPA limit 4000 µg/L
worst single sample: 1210 µg/L
5/5 SYR4 2013–2018
Gross Alpha, Excl. Radon And U
6.19 pCi/L 41%
of the EPA limit 15 pCi/L
worst single sample: 6.2 pCi/L
3/3 SYR4 2013–2019
Arsenic
1 µg/L 10%
of the EPA limit 10 µg/L
 2/2 SYR4 2016–2018
Barium
239 µg/L 12%
of the EPA limit 2000 µg/L
worst single sample: 240 µg/L
2/2 SYR4 2016–2018
Combined Radium (-226 And -228)
1.2 pCi/L 24%
of the EPA limit 5 pCi/L
 1/3 SYR4 2013–2019
71 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, TotalAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromodichloromethaneBromoformChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChloroformChromiumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDibromoacetic AcidDibromochloromethaneDichloroacetic AcidDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNitriteOxamylPentachlorophenolPicloramSeleniumSimazineStyreneTTHMTetrachloroethyleneThallium, TotalTolueneTotal Haloacetic Acids (HAA5)Total Polychlorinated Biphenyls (PCB)ToxapheneTrichloroacetic AcidTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
PHILLIPS, REBECCA
Phone
406-675-4491
Email
[email protected]

Frequently asked questions about Mission Dam Water

Is Mission Dam Water tap water safe to drink?

EPA monitoring detected 11 contaminants in Mission Dam 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 Mission Dam Water's water?

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

How many people does Mission Dam Water serve?

Mission Dam Water reports serving 87 people in Montana, per its EPA record.

Has Mission Dam Water had any water quality violations?

The EPA has 52 violations on file for Mission Dam Water, of which 29 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.