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 | 1580 µg/L 16% of the EPA limit 10000 µg/L Highest in the city: EAST DILLON WD · 2,501 people · 2019 | 3/4 | SYR4 |
| Nitrate-Nitrite | 1569.5 µg/L 16% of the EPA limit 10000 µg/L Highest in the city: EAST DILLON WD · 2,501 people · 2019 | 1/4 | SYR4 |
| Fluoride | 1022 µg/L 26% of the EPA limit 4000 µg/L Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 3/4 | SYR4 |
| TTHM | 105.1 µg/L 131% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 4/4 | SYR4 |
| Barium | 26.55 µg/L 1.3% of the EPA limit 2000 µg/L Main supplier: DILLON TOWN OF · 3,254 people · 2019
Highest in the city: 83 µg/L — EAST DILLON WD · 2,501 people · 2014 | 4/4 | SYR4 |
| Bromoform | 65.345 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 3/4 | SYR4 |
| Total Haloacetic Acids (HAA5) | 28.12 µg/L 47% of the EPA limit 60 µg/L Main supplier: DILLON TOWN OF · 3,254 people · 2019
Highest in the city: 64.38 µg/L — HAMILTON CREEK MD · 200 people · 2019 | 4/4 | SYR4 |
| Dibromochloromethane | 35.59 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 3/4 | SYR4 |
| Chloroform | 35.09 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 4/4 | SYR4 |
| Bromodichloromethane | 16.83 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 4/4 | SYR4 |
| Dichloroacetic Acid | 14.89 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 4/4 | SYR4 |
| Trichloroacetic Acid | 14.46 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 4/4 | SYR4 |
| Dibromoacetic Acid | 14.2 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 3/4 | SYR4 |
| Monochloroacetic Acid | 1.336 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019
Highest in the city: 5.2 µg/L — HAMILTON CREEK MD · 200 people · 2019 | 3/4 | SYR4 |
| Combined Uranium | 1.4 µg/L 4.7% of the EPA limit 30 µg/L Main supplier: DILLON TOWN OF · 3,254 people · 2012
Highest in the city: 3.9 µg/L — HAMILTON CREEK MD · 200 people · 2017 | 3/4 | SYR4 |
| Selenium | 2 µg/L 4% of the EPA limit 50 µg/L Main supplier: DILLON TOWN OF · 3,254 people · 2019
Highest in the city: 2.337 µg/L — DILLON VALLEY DISTRICT · 3,063 people · 2019 | 2/4 | SYR4 |
| Monobromoacetic Acid | 1.6565 µg/L No EPA limit set Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 1/4 | SYR4 |
| Chromium | 1 µg/L 1% of the EPA limit 100 µg/L Main supplier: DILLON TOWN OF · 3,254 people · 2019 | 1/4 | SYR4 |
| Gross Alpha, Excl. Radon And U | 0.5600 pCi/L 3.7% of the EPA limit 15 pCi/L Main supplier: DILLON TOWN OF · 3,254 people · 2012
Highest in the city: 0.7630 pCi/L — EAST DILLON WD · 2,501 people · 2018 | 3/4 | SYR4 |
| Combined Radium (-226 And -228) | 0.3000 pCi/L 6% of the EPA limit 5 pCi/L Main supplier: DILLON TOWN OF · 3,254 people · 2012
Highest in the city: 0.7000 pCi/L — HAMILTON CREEK MD · 200 people · 2012 | 2/4 | SYR4 |
| Lead | 0.0080 mg/L 53% of the EPA limit 0.0150 mg/L Main supplier: DILLON TOWN OF · 3,254 people · 2025 | 4/4 | 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 TOWN OF | 3,254 |
| DILLON VALLEY DISTRICT | 3,063 |
| EAST DILLON WD | 2,501 |
| HAMILTON CREEK MD | 200 |
Frequently asked questions about Dillon tap water
Is Dillon tap water safe to drink?
EPA testing detected 21 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?
4 public water suppliers report drinking-water monitoring for Dillon, Colorado 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, Nitrate-Nitrite, Fluoride, TTHM, 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.