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Tap water quality report

ZIP 59403 — Great Falls, MT

EPA monitoring across the 1 water supplier serving ZIP 59403 in Great Falls, MT detected 21 contaminants. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier below, with the EPA limit for each.

1
water supplier
60,000
people served
21
contaminants found

What was found in ZIP 59403

The level at this ZIP's main supplier, the highest level anywhere in it, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Copper
1176 µg/L 90%
of the EPA limit 1300 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Fluoride
900 µg/L 23%
of the EPA limit 4000 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Nitrate-Nitrite
270 µg/L 2.7%
of the EPA limit 10000 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Lithium
80.8 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2023
1/1 UCMR-5
Total Haloacetic Acids (HAA5)
69.8 µg/L 116%
of the EPA limit, at the 95th percentile of samples — 60 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
TTHM
67 µg/L 84%
of the EPA limit 80 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Chloroform
53 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Barium
50 µg/L 2.5%
of the EPA limit 2000 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Trichloroacetic Acid
40 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Dichloroacetic Acid
30.6 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Bromodichloromethane
14 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Lead
8 µg/L 53%
of the EPA limit 15 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Arsenic
4 µg/L 40%
of the EPA limit 10 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Gross Alpha, Excl. Radon And U
3.2 pCi/L 21%
of the EPA limit 15 pCi/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2014
1/1 SYR4
Dibromochloromethane
2.8 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Monochloroacetic Acid
2.735 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Monobromoacetic Acid
1.475 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Combined Uranium
1 µg/L 3.3%
of the EPA limit 30 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2014
1/1 SYR4
Dibromoacetic Acid
0.6500 µg/L
No EPA limit set
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Hexachlorocyclopentadiene
0.1195 µg/L 0.2%
of the EPA limit 50 µg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
1/1 SYR4
Lead
0.0120 mg/L 80%
of the EPA limit 0.0150 mg/L
Main supplier: GREAT FALLS CITY OF · 60,000 people · 2026
1/1 LCR
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 the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.

Water suppliers serving ZIP 59403

SupplierStatePopulation served
GREAT FALLS CITY OF MT 60,000

Frequently asked questions about ZIP 59403 tap water

Is the tap water in ZIP 59403 safe to drink?

EPA testing detected 21 contaminants across the water suppliers serving ZIP 59403. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and your utility's annual Consumer Confidence Report for the official status.

Which water suppliers serve ZIP 59403?

1 public water supplier report EPA drinking-water monitoring for ZIP 59403. Each is listed above with its population served.

What contaminants are in ZIP 59403's water?

EPA monitoring detected Copper, Fluoride, Nitrate-Nitrite, Lithium, Total Haloacetic Acids (HAA5), and others across this ZIP's suppliers. The full list with levels and sources is above.