What was found in Dillon'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 | 2330 µg/L 23% of the EPA limit 10000 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2019
Highest in the city: 3894.5 µg/L — WESTERN MOBILE VILLAGE DILLON · 75 people · 2019 | 7/7 | SYR4 |
| Copper | 764.8 µg/L 59% of the EPA limit 1300 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2018
Highest in the city: 1171 µg/L — HILDRETH SUBDIVISION NO 2 · 300 people · 2019 | 7/7 | SYR4 |
| Fluoride | 560 µg/L 14% of the EPA limit 4000 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2019
Highest in the city: 585 µg/L — CLARKS LOOKOUT · 62 people · 2019 | 6/7 | SYR4 |
| Barium | 87 µg/L 4.4% of the EPA limit 2000 µg/L Highest in the city: HILDRETH SUBDIVISION NO 2 · 300 people · 2015 | 2/7 | SYR4 |
| Arsenic | 6 µg/L 60% of the EPA limit 10 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2019
Highest in the city: 24 µg/L — CLARKS LOOKOUT · 62 people · 2019 | 7/7 | SYR4 |
| Lithium | 21 µg/L No EPA limit set Main supplier: DILLON CITY OF · 4,300 people · 2024 | 1/7 | UCMR-5 |
| Gross Alpha, Excl. Radon And U | 5.24 pCi/L 35% of the EPA limit 15 pCi/L Main supplier: DILLON CITY OF · 4,300 people · 2014
Highest in the city: 18.943 pCi/L — SKYLINE TR CT AND RV PARK · 75 people · 2018 | 6/7 | SYR4 |
| TTHM | 15.7 µg/L 20% of the EPA limit 80 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Combined Uranium | 5 µg/L 17% of the EPA limit 30 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2014
Highest in the city: 11.9 µg/L — SKYLINE TR CT AND RV PARK · 75 people · 2018 | 7/7 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 8.3 µg/L 138% of the EPA limit, at the 95th percentile of samples — 6 µg/L Highest in the city: WESTERN MOBILE VILLAGE DILLON · 75 people · 2019 | 1/7 | SYR4 |
| Lead | 3.05 µg/L 20% of the EPA limit 15 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2018
Highest in the city: 8.1 µg/L — WESTERN MOBILE VILLAGE DILLON · 75 people · 2018 | 6/7 | SYR4 |
| Dibromochloromethane | 7.35 µg/L No EPA limit set Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Gross Beta Particle Activity | 6.95 pCi/L No EPA limit set Highest in the city: WESTERN MOBILE VILLAGE DILLON · 75 people · 2015 | 1/7 | SYR4 |
| Bromoform | 5.5 µg/L No EPA limit set Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Chromium | 5.25 µg/L 5.3% of the EPA limit 100 µg/L Highest in the city: SKYLINE TR CT AND RV PARK · 75 people · 2017 | 1/7 | SYR4 |
| Selenium | 4.5 µg/L 9% of the EPA limit 50 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2019
Highest in the city: 4.6415 µg/L — SKYLINE TR CT AND RV PARK · 75 people · 2017 | 4/7 | SYR4 |
| Combined Radium (-226 And -228) | 0.8900 pCi/L 18% of the EPA limit 5 pCi/L Main supplier: DILLON CITY OF · 4,300 people · 2014
Highest in the city: 4.3 pCi/L — CLARKS LOOKOUT · 62 people · 2013 | 5/7 | SYR4 |
| Total Haloacetic Acids (HAA5) | 3.515 µg/L 5.9% of the EPA limit 60 µg/L Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Bromodichloromethane | 3.28 µg/L No EPA limit set Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Dibromoacetic Acid | 2.965 µg/L No EPA limit set Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Dichloroacetic Acid | 1 µg/L No EPA limit set Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Chloroform | 0.9090 µg/L No EPA limit set Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Monobromoacetic Acid | 0.8000 µg/L No EPA limit set Main supplier: DILLON CITY OF · 4,300 people · 2019 | 1/7 | SYR4 |
| Antimony, Total | 0.6250 µg/L 10% of the EPA limit 6 µg/L Highest in the city: SKYLINE TR CT AND RV PARK · 75 people · 2017 | 1/7 | SYR4 |
| Thallium, Total | 0.0315 µg/L 1.6% of the EPA limit 2 µg/L Highest in the city: SKYLINE TR CT AND RV PARK · 75 people · 2017 | 1/7 | SYR4 |
| Lead | 0.0030 mg/L 20% of the EPA limit 0.0150 mg/L Main supplier: DILLON CITY OF · 4,300 people · 2024
Highest in the city: 0.0040 mg/L — WESTERN MOBILE VILLAGE DILLON · 75 people · 2027 | 7/7 | 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 Dillon
| Supplier | Population served |
|---|---|
| DILLON CITY OF | 4,300 |
| KELLER SUBDIVISION NO 2 HOA | 300 |
| HILDRETH SUBDIVISION NO 2 | 300 |
| HILDRETH SUBDIVISION NO 3 | 128 |
| WESTERN MOBILE VILLAGE DILLON | 75 |
| SKYLINE TR CT AND RV PARK | 75 |
| CLARKS LOOKOUT | 62 |
Frequently asked questions about Dillon tap water
Is Dillon tap water safe to drink?
EPA testing detected 26 contaminants in the water serving Dillon. 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 Dillon?
7 public water suppliers report drinking-water monitoring for Dillon, Montana to the EPA. Each is listed above with its population served.
What contaminants are in Dillon's water?
The contaminants EPA monitoring detected in Dillon include Nitrate-Nitrite, Copper, Fluoride, Barium, Arsenic. 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.