County · Texas
Williamson County, Texas: drinking water records
This overview covers 19 ZIP codes and 39 community water systems in Williamson County. It also stands in for 1 ZIP codes whose utility has too little EPA data for a page of its own.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems with the most complete records
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| City of Georgetown TX2460001 | 191,639 | 660 | 7 | 1 | 2.2 ppb |
| Jonah Water SUD TX2460022 | 29,861 | 480 | 7 | 2 | 2.5 ppb |
| Sonterra MUD TX2460157 | 16,614 | 180 | 4 | 2 | 0.4 ppb |
| City of Bartlett TX2460006 | 2,950 | 60 | 0 | 5 | 2.7 ppb |
| City of Round Rock TX2460003 | 130,662 | 300 | 4 | 0 | 5.1 ppb |
| City of Leander TX2460012 | 98,330 | 240 | 1 | 0 | 1.1 ppb |
| City of Cedar Park TX2460009 | 86,939 | 240 | 1 | 0 | 4.0 ppb |
| City of Hutto TX2460007 | 29,580 | 240 | 0 | 0 | 0 ppb |
| City of Taylor TX2460004 | 20,622 | 120 | 5 | 0 | 1.9 ppb |
| Brushy Creek MUD TX2460061 | 18,314 | 120 | 5 | 0 | 1.3 ppb |
| Jarrell Schwertner WSC TX2460011 | 9,681 | 660 | 2 | 0 | 0 ppb |
| City of Liberty Hill TX2460013 | 8,777 | 0 | 0 | 4 | 2.1 ppb |
| Williamson County Wsid 3 TX2460152 | 8,265 | 60 | 3 | 0 | 0.5 ppb |
| Block House MUD TX2460110 | 6,618 | 95 | 1 | 0 | 0.8 ppb |
| Williamson Travis County MUD 1 TX2460120 | 5,793 | 120 | 0 | 0 | 2.0 ppb |
| Fern Bluff MUD TX2460128 | 5,682 | 120 | 2 | 0 | 0 ppb |
| Williamson County MUD 11 TX2460159 | 4,248 | 120 | 2 | 0 | 5.0 ppb |
| Williamson County MUD 10 TX2460145 | 3,513 | 120 | 3 | 0 | 1.3 ppb |
| Blessing Mobile Home Park TX2460031 | 1,518 | 0 | 0 | 1 | 3.6 ppb |
| City of Florence TX2460005 | 1,136 | 0 | 0 | 5 | 2.2 ppb |
| City of Thrall TX2460015 | 975 | 0 | 0 | 2 | 1.3 ppb |
| City of Jarrell TX2460169 | 3,450 | 0 | 0 | 0 | 1.5 ppb |
| Paloma Lake MUD 1 TX2460164 | 3,111 | 0 | 0 | 0 | 0 ppb |
| Vista Oaks MUD TX2460139 | 2,724 | 0 | 0 | 0 | 2.3 ppb |
| Paloma Lake MUD 2 TX2460165 | 2,265 | 0 | 0 | 0 | 1.8 ppb |
ZIP reports in Williamson County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 78674.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.