What was found in Highlands Ranch'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 |
|---|---|---|---|
| Fluoride | 1020 µg/L 26% of the EPA limit 4000 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Nitrate | 168.5 µg/L 1.7% of the EPA limit 10000 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Nitrate-Nitrite | 151 µg/L 1.5% of the EPA limit 10000 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Barium | 110 µg/L 5.5% of the EPA limit 2000 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| TTHM | 51.06 µg/L 64% of the EPA limit 80 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Lithium | 35.2 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2024 | 1/1 | UCMR-5 |
| Dibromochloromethane | 21.995 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Bromodichloromethane | 21.745 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 20.9 µg/L 35% of the EPA limit 60 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Chloroform | 11.3 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Bromoform | 10.165 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Dichloroacetic Acid | 9.9375 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Gross Beta Particle Activity | 6.25 pCi/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Dibromoacetic Acid | 5.7775 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Combined Uranium | 5.46 µg/L 18% of the EPA limit 30 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Gross Alpha, Excl. Radon And U | 4.9 pCi/L 33% of the EPA limit 15 pCi/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Trichloroacetic Acid | 4.13 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Arsenic | 3.5 µg/L 35% of the EPA limit 10 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Combined Radium (-226 And -228) | 3.45 pCi/L 69% of the EPA limit 5 pCi/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Selenium | 2.75 µg/L 5.5% of the EPA limit 50 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Chromium | 2 µg/L 2% of the EPA limit 100 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 1.9 µg/L 32% of the EPA limit 6 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Monobromoacetic Acid | 1.5 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Mercury | 0.2000 µg/L 10% of the EPA limit 2 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Cadmium | 0.1600 µg/L 3.2% of the EPA limit 5 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Hexachlorocyclopentadiene | 0.1300 µg/L 0.3% of the EPA limit 50 µg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2019 | 1/1 | SYR4 |
| Pfba | 0.0087 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2024 | 1/1 | UCMR-5 |
| Pfpea | 0.0057 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2024 | 1/1 | UCMR-5 |
| Pfhxa | 0.0051 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2024 | 1/1 | UCMR-5 |
| PFBS | 0.0050 µg/L No EPA limit set Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2024 | 1/1 | UCMR-5 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: HIGHLANDS RANCH WSD · 103,444 people · 2025 | 1/1 | 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 Highlands Ranch
| Supplier | Population served |
|---|---|
| HIGHLANDS RANCH WSD | 103,444 |
Frequently asked questions about Highlands Ranch tap water
Is Highlands Ranch tap water safe to drink?
EPA testing detected 31 contaminants in the water serving Highlands Ranch. 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 Highlands Ranch?
1 public water supplier report drinking-water monitoring for Highlands Ranch, Colorado to the EPA. Each is listed above with its population served.
What contaminants are in Highlands Ranch's water?
The contaminants EPA monitoring detected in Highlands Ranch include Fluoride, Nitrate, Nitrate-Nitrite, Barium, TTHM. 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.