- EPA's UCMR 5 testing looked for 30 contaminants here and found 5.
- Lithium: found in 6 of 10 samples, average 6.71 µg/L, highest 13.5 µg/L (EPA UCMR 5 testing, Oct 2024–Jul 2025)
- PFBS (a PFAS): found in 2 of 10 samples, average 1.2 ppt, highest 6.7 ppt (EPA UCMR 5 testing, Oct 2024–Jul 2025)
- PFPeA (a PFAS): found in 2 of 10 samples, average 1 ppt, highest 6.7 ppt (EPA UCMR 5 testing, Oct 2024–Jul 2025)
- PFBA (a PFAS): found in 1 of 10 samples, average 0.50 ppt, highest 5.1 ppt (EPA UCMR 5 testing, Oct 2024–Jul 2025)
- PFHxA (a PFAS): found in 1 of 10 samples, average 0.40 ppt, highest 3.7 ppt (EPA UCMR 5 testing, Oct 2024–Jul 2025)
- Lead, 90th percentile: 5.05 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2021–Dec 31, 2023). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
Public EPA test results
Can you drink Round Rock tap water? What EPA records show
EPA TX2460003 · serves Williamson County, TX · about 130,662 people (EPA SDWIS)
This report shows EPA's federal records for this water system: UCMR 5 testing, lead testing and violations. It isn't a test of the water at your tap, and it has no Water Score.
Public EPA test results
City of Round Rock (EPA TX2460003)
EPA data as of October 14, 2026. For Round Rock's main utility, City of Round Rock: We found no health-based violations in EPA's records for this system (TX2460003) since July 1, 2021, as of October 14, 2026. PFOA and PFOS were not detected at or above EPA's reporting level in EPA's UCMR 5 testing.
What EPA records show for City of Round Rock, as of October 14, 2026
We found no health-based violations in EPA's records for this system (TX2460003) since July 1, 2021, as of October 14, 2026.
Source: EPA ECHO record for City of Round Rock (SDWIS). Data as of October 14, 2026.
Lead, 90th percentile: 5.05 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2021–Dec 31, 2023). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
EPA's UCMR 5 testing looked for 30 contaminants here and found 5.
PFOA and PFOS were not detected at or above EPA's reporting level in EPA's UCMR 5 testing.
Source: EPA records (SDWIS, UCMR 5). SDWIS: data as of Oct 14, 2026. EPA UCMR 5 data, samples through June 2026.
Your water bill names your utility.
Does City of Round Rock use chloramine?
EPA treatment records (state-reported) list chloramines for City of Round Rock. EPA record