What was found in Round Rock'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 | 5790 µg/L 58% of the EPA limit 10000 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019 | 3/6 | SYR4 |
| Nitrate-Nitrite | 5730 µg/L 57% of the EPA limit 10000 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2015 | 2/6 | SYR4 |
| Fluoride | 315 µg/L 7.9% of the EPA limit 4000 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 686.5 µg/L — BRUSHY CREEK MUD · 18,314 people · 2019 | 3/6 | SYR4 |
| Copper | 400 µg/L 31% of the EPA limit 1300 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2018 | 5/6 | SYR4 |
| Cyanide | 115 µg/L 57% of the EPA limit 200 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019 | 3/6 | SYR4 |
| TTHM | 64.14 µg/L 80% of the EPA limit 80 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 73.88 µg/L — WALSH RANCH MUD · 714 people · 2019 | 6/6 | SYR4 |
| Barium | 53.5 µg/L 2.7% of the EPA limit 2000 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 56.02 µg/L — BRUSHY CREEK REGIONAL UTILITY AUTHORITY · 0 people · 2019 | 3/6 | SYR4 |
| Bromodichloromethane | 24.01 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 30.085 µg/L — WALSH RANCH MUD · 714 people · 2019 | 6/6 | SYR4 |
| Total Haloacetic Acids (HAA5) | 25.64 µg/L 43% of the EPA limit 60 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 29.63 µg/L — FERN BLUFF MUD · 5,682 people · 2019 | 6/6 | SYR4 |
| Chloroform | 19.89 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 24.62 µg/L — BRUSHY CREEK MUD · 18,314 people · 2019 | 6/6 | SYR4 |
| Dibromochloromethane | 23.4 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 23.56 µg/L — WALSH RANCH MUD · 714 people · 2019 | 6/6 | SYR4 |
| Bromoform | 17.545 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019 | 6/6 | SYR4 |
| Lithium | 13.5 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2025
Highest in the city: 16.3 µg/L — BRUSHY CREEK MUD · 18,314 people · 2024 | 3/6 | UCMR-5 |
| Dichloroacetic Acid | 13 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 15.7 µg/L — BRUSHY CREEK MUD · 18,314 people · 2019 | 6/6 | SYR4 |
| Lead | 7.91 µg/L 53% of the EPA limit 15 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2018
Highest in the city: 14.286 µg/L — FERN BLUFF MUD · 5,682 people · 2019 | 4/6 | SYR4 |
| Trichloroacetic Acid | 8.345 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 10.725 µg/L — WALSH RANCH MUD · 714 people · 2019 | 6/6 | SYR4 |
| Dibromoacetic Acid | 9.42 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 10.27 µg/L — WALSH RANCH MUD · 714 people · 2019 | 6/6 | SYR4 |
| Monochloroacetic Acid | 5.32 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019 | 5/6 | SYR4 |
| Selenium | 4.38 µg/L 8.8% of the EPA limit 50 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019 | 2/6 | SYR4 |
| Gross Beta Particle Activity | 4 pCi/L No EPA limit set Highest in the city: BRUSHY CREEK REGIONAL UTILITY AUTHORITY · 0 people · 2019 | 1/6 | SYR4 |
| Monobromoacetic Acid | 2 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019
Highest in the city: 3.025 µg/L — BRUSHY CREEK MUD · 18,314 people · 2019 | 5/6 | SYR4 |
| Chromium | 2.0336 µg/L 2% of the EPA limit 100 µg/L Highest in the city: BRUSHY CREEK MUD · 18,314 people · 2019 | 1/6 | SYR4 |
| Arsenic | 1.68 µg/L 17% of the EPA limit 10 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019 | 3/6 | SYR4 |
| Combined Radium (-226 And -228) | 1.475 pCi/L 30% of the EPA limit 5 pCi/L Highest in the city: BRUSHY CREEK MUD · 18,314 people · 2018 | 1/6 | SYR4 |
| Atrazine | 0.1795 µg/L 6% of the EPA limit 3 µg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2019 | 2/6 | SYR4 |
| PFBS | 0.0067 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2025 | 2/6 | UCMR-5 |
| Pfpea | 0.0067 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2025 | 3/6 | UCMR-5 |
| Pfba | 0.0051 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2025
Highest in the city: 0.0061 µg/L — BRUSHY CREEK MUD · 18,314 people · 2024 | 2/6 | UCMR-5 |
| Lead | 0.0050 mg/L 34% of the EPA limit 0.0150 mg/L Main supplier: CITY OF ROUND ROCK · 130,662 people · 2023 | 5/6 | LCR |
| Pfhxa | 0.0037 µg/L No EPA limit set Main supplier: CITY OF ROUND ROCK · 130,662 people · 2025
Highest in the city: 0.0038 µg/L — BRUSHY CREEK MUD · 18,314 people · 2024 | 2/6 | UCMR-5 |
| PFHXS | 0.0037 µg/L No EPA limit set Highest in the city: BRUSHY CREEK MUD · 18,314 people · 2024 | 1/6 | UCMR-5 |
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 Round Rock
| Supplier | Population served |
|---|---|
| CITY OF ROUND ROCK | 130,662 |
| BRUSHY CREEK MUD | 18,314 |
| FERN BLUFF MUD | 5,682 |
| BLESSING MOBILE HOME PARK | 1,518 |
| WALSH RANCH MUD | 714 |
| BRUSHY CREEK REGIONAL UTILITY AUTHORITY | 0 |
Frequently asked questions about Round Rock tap water
Is Round Rock tap water safe to drink?
EPA testing detected 31 contaminants in the water serving Round Rock. 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 Round Rock?
6 public water suppliers report drinking-water monitoring for Round Rock, Texas to the EPA. Each is listed above with its population served.
What contaminants are in Round Rock's water?
The contaminants EPA monitoring detected in Round Rock include Nitrate, Nitrate-Nitrite, Fluoride, Copper, Cyanide. 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.