What was found in ZIP 59405
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.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Copper | 1176 µg/L 90% of the EPA limit 1300 µg/L Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
Highest in the ZIP: 1482.5 µg/L — MALMSTROM AIR FORCE BASE · 8,850 people · 2018 | 2/2 | SYR4 |
| Fluoride | 900 µg/L 23% of the EPA limit 4000 µg/L Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 1/2 | 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 | 1/2 | SYR4 |
| TTHM | 67 µg/L 84% of the EPA limit 80 µg/L Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
Highest in the ZIP: 81 µg/L — MALMSTROM AIR FORCE BASE · 8,850 people · 2019 | 2/2 | SYR4 |
| Lithium | 80.8 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2023 | 2/2 | UCMR-5 |
| Chloroform | 53 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
Highest in the ZIP: 71.5 µg/L — MALMSTROM AIR FORCE BASE · 8,850 people · 2019 | 2/2 | SYR4 |
| 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 | 2/2 | SYR4 |
| Barium | 50 µg/L 2.5% of the EPA limit 2000 µg/L Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 1/2 | SYR4 |
| Trichloroacetic Acid | 40 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 2/2 | SYR4 |
| Dichloroacetic Acid | 30.6 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 2/2 | SYR4 |
| Bromodichloromethane | 14 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 2/2 | SYR4 |
| Lead | 8 µg/L 53% of the EPA limit 15 µg/L Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 2/2 | SYR4 |
| Arsenic | 4 µg/L 40% of the EPA limit 10 µg/L Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 1/2 | 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 | 1/2 | SYR4 |
| Dibromochloromethane | 2.8 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
Highest in the ZIP: 3.125 µg/L — MALMSTROM AIR FORCE BASE · 8,850 people · 2019 | 2/2 | SYR4 |
| Monochloroacetic Acid | 2.735 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 2/2 | SYR4 |
| Monobromoacetic Acid | 1.475 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019 | 2/2 | 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 | 1/2 | SYR4 |
| Dibromoacetic Acid | 0.6500 µg/L No EPA limit set Main supplier: GREAT FALLS CITY OF · 60,000 people · 2019
Highest in the ZIP: 0.7590 µg/L — MALMSTROM AIR FORCE BASE · 8,850 people · 2019 | 2/2 | 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 | 1/2 | 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 | 2/2 | LCR |
| Pfba | 0.0070 µg/L No EPA limit set Highest in the ZIP: MALMSTROM AIR FORCE BASE · 8,850 people · 2023 | 1/2 | UCMR-5 |
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 59405
| Supplier | State | Population served |
|---|---|---|
| GREAT FALLS CITY OF | MT | 60,000 |
| MALMSTROM AIR FORCE BASE | MT | 8,850 |
Frequently asked questions about ZIP 59405 tap water
Is the tap water in ZIP 59405 safe to drink?
EPA testing detected 22 contaminants across the water suppliers serving ZIP 59405. 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 59405?
2 public water suppliers report EPA drinking-water monitoring for ZIP 59405. Each is listed above with its population served.
What contaminants are in ZIP 59405's water?
EPA monitoring detected Copper, Fluoride, Nitrate-Nitrite, TTHM, Lithium, and others across this ZIP's suppliers. The full list with levels and sources is above.