What was found in Box Elder'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 | 1503.5 µg/L 15% of the EPA limit 10000 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 3/3 | SYR4 |
| Fluoride | 1080 µg/L 27% of the EPA limit 4000 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 3/3 | SYR4 |
| Copper | 227.25 µg/L 17% of the EPA limit 1300 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019
Highest in the city: 685.6 µg/L — EAGLEMAN COMMUNITY WATER · 400 people · 2018 | 3/3 | SYR4 |
| Nitrate | 250 µg/L 2.5% of the EPA limit 10000 µg/L Highest in the city: ROCKY BOY AGENCY WATER SYSTEM · 1,442 people · 2016 | 1/3 | SYR4 |
| Barium | 137.5 µg/L 6.9% of the EPA limit 2000 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 2/3 | SYR4 |
| TTHM | 35.6 µg/L 45% of the EPA limit 80 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 3/3 | SYR4 |
| Chromium | 32 µg/L 32% of the EPA limit 100 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 2/3 | SYR4 |
| Chloroform | 29.85 µg/L No EPA limit set Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 21.1 µg/L 35% of the EPA limit 60 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2018 | 3/3 | SYR4 |
| Lead | 1 µg/L 6.7% of the EPA limit 15 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019
Highest in the city: 18.15 µg/L — EAGLEMAN COMMUNITY WATER · 400 people · 2018 | 3/3 | SYR4 |
| Dichloroacetic Acid | 12.8 µg/L No EPA limit set Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2018 | 3/3 | SYR4 |
| Selenium | 12 µg/L 24% of the EPA limit 50 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 2/3 | SYR4 |
| Trichloroacetic Acid | 8.24 µg/L No EPA limit set Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2018
Highest in the city: 8.7755 µg/L — ROCKY BOY AGENCY WATER SYSTEM · 1,442 people · 2018 | 3/3 | SYR4 |
| Gross Alpha, Excl. Radon And U | 7.9 pCi/L 53% of the EPA limit 15 pCi/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 3/3 | SYR4 |
| Toluene | 6.7 µg/L 0.7% of the EPA limit 1000 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 2/3 | SYR4 |
| Bromodichloromethane | 6.44 µg/L No EPA limit set Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 3/3 | SYR4 |
| Arsenic | 6 µg/L 60% of the EPA limit 10 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 3/3 | SYR4 |
| Combined Uranium | 5.28 µg/L 18% of the EPA limit 30 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 2/3 | SYR4 |
| Combined Radium (-226 And -228) | 2.4 pCi/L 48% of the EPA limit 5 pCi/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019
Highest in the city: 3.435 pCi/L — EAGLEMAN COMMUNITY WATER · 400 people · 2013 | 3/3 | SYR4 |
| Xylenes, Total | 2.9 µg/L 0% of the EPA limit 10000 µg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 2/3 | SYR4 |
| Dibromochloromethane | 0.9600 µg/L No EPA limit set Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2019 | 2/3 | SYR4 |
| Monochloroacetic Acid | 0.8500 µg/L No EPA limit set Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2018 | 1/3 | SYR4 |
| Dibromoacetic Acid | 0.3300 µg/L No EPA limit set Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2018 | 1/3 | SYR4 |
| Asbestos | 0.2000 MFL 2.9% of the EPA limit 7 MFL Highest in the city: ROCKY BOY AGENCY WATER SYSTEM · 1,442 people · 2015 | 1/3 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: ROCKY BOY'S RURAL WATER · 2,000 people · 2028
Highest in the city: 0.0020 mg/L — ROCKY BOY AGENCY WATER SYSTEM · 1,442 people · 2026 | 3/3 | 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 Box Elder
| Supplier | Population served |
|---|---|
| ROCKY BOY'S RURAL WATER | 2,000 |
| ROCKY BOY AGENCY WATER SYSTEM | 1,442 |
| EAGLEMAN COMMUNITY WATER | 400 |
Frequently asked questions about Box Elder tap water
Is Box Elder tap water safe to drink?
EPA testing detected 25 contaminants in the water serving Box Elder. 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 Box Elder?
3 public water suppliers report drinking-water monitoring for Box Elder, Montana to the EPA. Each is listed above with its population served.
What contaminants are in Box Elder's water?
The contaminants EPA monitoring detected in Box Elder include Nitrate-Nitrite, Fluoride, Copper, Nitrate, 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.