What was found in Hamilton's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate-Nitrite | 2936 µg/L 29% of the EPA limit 10000 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2019 | 13/13 | SYR4 |
| Nitrate | 1560 µg/L 16% of the EPA limit 10000 µg/L Highest in the city: DALY ESTATES SUBDIVISION · 123 people · 2017 | 4/13 | SYR4 |
| Copper | 1135 µg/L 87% of the EPA limit 1300 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2017
Highest in the city: 1472 µg/L — SAWTOOTH VILLA · 70 people · 2019 | 13/13 | SYR4 |
| Fluoride | 200 µg/L 5% of the EPA limit 4000 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2013
Highest in the city: 590 µg/L — STOCK FARM THE · 150 people · 2019 | 12/13 | SYR4 |
| Barium | 50 µg/L 2.5% of the EPA limit 2000 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2013
Highest in the city: 80 µg/L — STOCK FARM THE · 150 people · 2019 | 3/13 | SYR4 |
| TTHM | 23.565 µg/L 29% of the EPA limit 80 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2019 | 3/13 | SYR4 |
| Lead | 22.1 µg/L 147% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2017 | 12/13 | SYR4 |
| Chloroform | 19.61 µg/L No EPA limit set Main supplier: HAMILTON CITY OF · 5,660 people · 2019 | 3/13 | SYR4 |
| Arsenic | 2 µg/L 20% of the EPA limit 10 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2017
Highest in the city: 8 µg/L — STOCK FARM THE · 150 people · 2019 | 6/13 | SYR4 |
| Combined Uranium | 2.85 µg/L 9.5% of the EPA limit 30 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2017
Highest in the city: 8 µg/L — STOCK FARM THE · 150 people · 2019 | 11/13 | SYR4 |
| Total Haloacetic Acids (HAA5) | 5.6 µg/L 9.3% of the EPA limit 60 µg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2019 | 2/13 | SYR4 |
| Dibromochloromethane | 1.216 µg/L No EPA limit set Main supplier: HAMILTON CITY OF · 5,660 people · 2019
Highest in the city: 4.925 µg/L — STOCK FARM THE · 150 people · 2019 | 3/13 | SYR4 |
| Gross Alpha, Excl. Radon And U | 4.05 pCi/L 27% of the EPA limit 15 pCi/L Main supplier: HAMILTON CITY OF · 5,660 people · 2017
Highest in the city: 4.9 pCi/L — STOCK FARM THE · 150 people · 2019 | 8/13 | SYR4 |
| Combined Radium (-226 And -228) | 4.56 pCi/L 91% of the EPA limit 5 pCi/L Main supplier: HAMILTON CITY OF · 5,660 people · 2017 | 2/13 | SYR4 |
| Dichloroacetic Acid | 3.69 µg/L No EPA limit set Main supplier: HAMILTON CITY OF · 5,660 people · 2019 | 1/13 | SYR4 |
| Bromodichloromethane | 2.92 µg/L No EPA limit set Main supplier: HAMILTON CITY OF · 5,660 people · 2019 | 3/13 | SYR4 |
| Bromoform | 2.8 µg/L No EPA limit set Highest in the city: STOCK FARM THE · 150 people · 2019 | 1/13 | SYR4 |
| Trichloroacetic Acid | 2.39 µg/L No EPA limit set Main supplier: HAMILTON CITY OF · 5,660 people · 2019 | 1/13 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 2.385 µg/L 40% of the EPA limit 6 µg/L Highest in the city: WHITE BIRD COMMUNITY THE · 82 people · 2019 | 1/13 | SYR4 |
| Dibromoacetic Acid | 0.5700 µg/L No EPA limit set Main supplier: HAMILTON CITY OF · 5,660 people · 2019
Highest in the city: 2.09 µg/L — STOCK FARM THE · 150 people · 2019 | 2/13 | SYR4 |
| Cadmium | 1 µg/L 20% of the EPA limit 5 µg/L Highest in the city: BIG SKY TRAILER CT HAMILTON · 70 people · 2019 | 1/13 | SYR4 |
| Selenium | 1 µg/L 2% of the EPA limit 50 µg/L Highest in the city: STOCK FARM THE · 150 people · 2019 | 1/13 | SYR4 |
| Lead | 0.0010 mg/L 6.7% of the EPA limit 0.0150 mg/L Main supplier: HAMILTON CITY OF · 5,660 people · 2023
Highest in the city: 0.0050 mg/L — BIG SKY TRAILER CT HAMILTON · 70 people · 2024 | 13/13 | LCR |
| PFBS | 0.0031 µg/L No EPA limit set Main supplier: HAMILTON CITY OF · 5,660 people · 2024 | 1/13 | 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.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Hamilton
| Supplier | Population served |
|---|---|
| HAMILTON CITY OF | 5,660 |
| STOCK FARM THE | 150 |
| DALY ESTATES SUBDIVISION | 123 |
| WILD FLOWER HOA, THE | 120 |
| WESTANA MOBILE MANOR HAMILTON | 90 |
| ANTIGONE ACRES HOA | 85 |
| WHITE BIRD COMMUNITY THE | 82 |
| BLUEBIRD MB HM PARK HAMILTON | 75 |
| BIG SKY TRAILER CT HAMILTON | 70 |
| SAWTOOTH VILLA | 70 |
| HAMILTON MOBILE VILLAGE | 53 |
| HONEY LANE COMMUNITY | 50 |
| WARDS COVE WATER USERS | 45 |
Frequently asked questions about Hamilton tap water
Is Hamilton tap water safe to drink?
EPA testing detected 24 contaminants in the water serving Hamilton. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Hamilton?
13 public water suppliers report drinking-water monitoring for Hamilton, Montana to the EPA. Each is listed above with its population served.
What contaminants are in Hamilton's water?
The contaminants EPA monitoring detected in Hamilton include Nitrate-Nitrite, Nitrate, Copper, Fluoride, Barium. The full list, with the level at the main supplier and the data source, is in the table above.
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.