What was found in Manhattan'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 | 2099.5 µg/L 21% of the EPA limit 10000 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019
Highest in the city: 9687.5 µg/L — GODFREY CANYON ESTATES · 100 people · 2019 | 8/8 | SYR4 |
| Copper | 463.65 µg/L 36% of the EPA limit 1300 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 8/8 | SYR4 |
| Fluoride | 266.5 µg/L 6.7% of the EPA limit 4000 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2017
Highest in the city: 400 µg/L — CHURCHILL RETIREMENT HOME · 80 people · 2012 | 8/8 | SYR4 |
| Barium | 49 µg/L 2.5% of the EPA limit 2000 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2017
Highest in the city: 360 µg/L — DYKSTERHOUSE WELL USERS ASSOC · 28 people · 2018 | 8/8 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.82 pCi/L 19% of the EPA limit 15 pCi/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2017
Highest in the city: 20.025 pCi/L — SETTLEMENT THE · 100 people · 2019 | 5/8 | SYR4 |
| Combined Uranium | 6.7 µg/L 22% of the EPA limit 30 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2017
Highest in the city: 18.7 µg/L — GODFREY CANYON ESTATES · 100 people · 2018 | 7/8 | SYR4 |
| TTHM | 13.2 µg/L 16% of the EPA limit 80 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 1/8 | SYR4 |
| Lead | 7.79 µg/L 52% of the EPA limit 15 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019
Highest in the city: 10 µg/L — MANHATTAN CAMPER COURT · 105 people · 2019 | 7/8 | SYR4 |
| Arsenic | 2.825 µg/L 28% of the EPA limit 10 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2017
Highest in the city: 8.85 µg/L — SETTLEMENT THE · 100 people · 2017 | 8/8 | SYR4 |
| Selenium | 1.095 µg/L 2.2% of the EPA limit 50 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2017
Highest in the city: 5.55 µg/L — CHURCHILL NORTH SUBDIVISION · 155 people · 2017 | 8/8 | SYR4 |
| Bromodichloromethane | 4.8 µg/L No EPA limit set Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 1/8 | SYR4 |
| Chloroform | 4.26 µg/L No EPA limit set Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 1/8 | SYR4 |
| Combined Radium (-226 And -228) | 1.59 pCi/L 32% of the EPA limit 5 pCi/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2017
Highest in the city: 4.1 pCi/L — CHURCHILL NORTH SUBDIVISION · 155 people · 2018 | 5/8 | SYR4 |
| Total Haloacetic Acids (HAA5) | 4.04 µg/L 6.7% of the EPA limit 60 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 1/8 | SYR4 |
| Dibromochloromethane | 3.74 µg/L No EPA limit set Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 1/8 | SYR4 |
| Dichloroacetic Acid | 1.62 µg/L No EPA limit set Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 1/8 | SYR4 |
| Bromoform | 1.4 µg/L No EPA limit set Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 1/8 | SYR4 |
| Antimony, Total | 1.1 µg/L 18% of the EPA limit 6 µg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2017 | 1/8 | SYR4 |
| Dibromoacetic Acid | 0.6700 µg/L No EPA limit set Main supplier: MANHATTAN TOWN OF · 1,800 people · 2019 | 1/8 | SYR4 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: MANHATTAN TOWN OF · 1,800 people · 2024
Highest in the city: 0.0070 mg/L — MANHATTAN CAMPER COURT · 105 people · 2019 | 8/8 | 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.
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 Manhattan
| Supplier | Population served |
|---|---|
| MANHATTAN TOWN OF | 1,800 |
| CHURCHILL NORTH SUBDIVISION | 155 |
| MANHATTAN CAMPER COURT | 105 |
| GODFREY CANYON ESTATES | 100 |
| RIDERS TRAILER COURT | 100 |
| SETTLEMENT THE | 100 |
| CHURCHILL RETIREMENT HOME | 80 |
| DYKSTERHOUSE WELL USERS ASSOC | 28 |
Frequently asked questions about Manhattan tap water
Is Manhattan tap water safe to drink?
EPA testing detected 20 contaminants in the water serving Manhattan. 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 Manhattan?
8 public water suppliers report drinking-water monitoring for Manhattan, Montana to the EPA. Each is listed above with its population served.
What contaminants are in Manhattan's water?
The contaminants EPA monitoring detected in Manhattan include Nitrate-Nitrite, Copper, Fluoride, Barium, Gross Alpha, Excl. Radon And U. 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.