Williamson County Water Quality: 283 Violations (TX)
34 water systems · 18 ZIP codes · Home Safety Score Unavailable · 0 of 26 tracked ZIP records scored · Updated
Data: EPA Safe Drinking Water Information System (SDWIS), EPA ECHO Last verified:
Violation Trend
EPA violations across water systems in Williamson County.
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Find the Right Filter →Water Quality Overview
Williamson County has 34 community water systems across 18 directly mapped ZIP records. The systems report serving approximately 1,921,377 people. The available records contain 283 EPA violations, including 70 health-based violations.
Health-based violations account for 25% of all violations in Williamson County. These violations indicate contaminant levels that may pose direct risks to human health.
Violation Breakdown
| Violation Type | Count | Percentage |
|---|---|---|
| Health-based | 70 | 24.7% |
| Monitoring/Reporting | 213 | 75.3% |
| Total | 283 | 100% |
Health-based violations indicate contaminant levels exceeding EPA Maximum Contaminant Levels (MCLs). Monitoring violations indicate failures to test or report.
Cities with Most Violations
| Rank | City | Violations | Health-Based | ZIP Codes | Population |
|---|---|---|---|---|---|
| 1 | Georgetown | 53 | 12 | 3 | 118,718 |
| 2 | Round Rock | 52 | 12 | 3 | 184,890 |
| 3 | Liberty Hill | 28 | 5 | 1 | 24,146 |
| 4 | Jarrell | 28 | 6 | 1 | 12,526 |
| 5 | Florence | 22 | 7 | 1 | 4,686 |
| 6 | Thorndale | 17 | 5 | 1 | 3,297 |
| 7 | Bartlett | 15 | 2 | 1 | 2,473 |
| 8 | Cedar Park | 14 | 1 | 1 | 89,162 |
| 9 | Hutto | 14 | 5 | 1 | 43,466 |
| 10 | Taylor | 13 | 6 | 1 | 19,746 |
Violation Trend
Year-by-year EPA violations across water systems in Williamson County:
| Year | Total | Health-Based |
|---|---|---|
| 2021 | 8 | 8 |
| 2022 | 5 | 5 |
| 2024 | 17 | 17 |
| 2025 | 37 | 37 |
Most Common Contaminants
| Contaminant | Category | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 66 | 16 | Yes |
| Lead and Copper Rule | Treatment Technique | 55 | 16 | No |
| Stage 1 DBP Rule | Treatment Technique | 43 | 13 | No |
| Revised Total Coliform Rule | Microbiological | 20 | 11 | No |
| Stage 2 DBP Rule | Treatment Technique | 20 | 9 | Yes |
| Total Coliform | Microbiological | 18 | 10 | No |
| Surface Water Treatment Rule | Treatment Technique | 10 | 8 | No |
| Fecal Coliform | Microbiological | 5 | 5 | Yes |
| Gross Alpha | Radionuclides | 4 | 2 | Yes |
| Gross Beta | Radionuclides | 4 | 2 | Yes |
Water Data and the Home Safety Score
This page reports EPA water-system facts without converting the broader Home Safety Score into a drinking-water grade. The county Home Safety grade (unavailable) is a separate multi-source index that also requires PFAS screening, radon, and annual air-quality evidence. Check each ZIP report for the versioned score and its component coverage.
Water Systems in Williamson County
Williamson County is served by 34 community water systems, averaging 1.3 systems per ZIP code. Each system is independently regulated and tested by the EPA. Larger systems serving more people typically have more extensive monitoring requirements.
Water systems in Williamson County source water from a mix of surface water (rivers, reservoirs) and groundwater (wells, aquifers). Source type affects which contaminants are most likely to be detected.
How to Check Your Water in Williamson County
Enter your ZIP code on ZipCheckup for detailed water-system data including contaminant levels and violation history; the Home Safety Score is shown separately with its model version
Request your CCR — every water utility must provide an annual Consumer Confidence Report
Get a home test — certified kits ($20-$50) or professional lab tests ($150-$400) can detect contaminants not covered by routine testing
Consider filtration — NSF-certified filters can address specific contaminants found in your area
Check for lead — homes built before 1986 should test for lead regardless of utility compliance
EPA Enforcement
The EPA and state regulators have taken 180 enforcement actions against water systems in Williamson County. Enforcement actions range from compliance assistance and administrative orders to formal penalties. Systems under enforcement are required to remediate violations and may face ongoing monitoring requirements.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Enforcement: EPA ECHO
Source publication schedules vary. See the page source and verification fields for available timing evidence.
Water Quality by ZIP Code in Williamson County
Water quality varies across Williamson County's 18 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | City | Violations | Health | |
|---|---|---|---|---|
| 76537 | Jarrell | 28 | 6 | View → |
| 78642 | Liberty Hill | 28 | 5 | View → |
| 78681 | Round Rock | 26 | 3 | View → |
| 78633 | Georgetown | 23 | 6 | View → |
| 76527 | Florence | 22 | 7 | View → |
| 78628 | Georgetown | 20 | 5 | View → |
| 76577 | Thorndale | 17 | 5 | View → |
| 78664 | Round Rock | 17 | 8 | View → |
| 76511 | Bartlett | 15 | 2 | View → |
| 78613 | Cedar Park | 14 | 1 | View → |
| 78634 | Hutto | 14 | 5 | View → |
| 76574 | Taylor | 13 | 6 | View → |
| 76530 | Granger | 12 | 1 | View → |
| 76578 | Thrall | 12 | 6 | View → |
| 78626 | Georgetown | 10 | 1 | View → |
| 78665 | Round Rock | 9 | 1 | View → |
| 78717 | Austin | 2 | 1 | View → |
| 78729 | Austin | 1 | 1 | View → |
What are EPA health violations?
Health-based violations mean a contaminant was detected above the EPA's Maximum Contaminant Level (MCL) - the legal limit designed to protect human health. Williamson County has 70 such violations. Not all violations cause illness, but repeated exceedances increase risk, especially for children and immunocompromised individuals.
Water facts and the Home Safety Score
This page reports water evidence separately. A broader Home Safety Score is not published here unless the versioned model identity and complete required component coverage are available.
Not sure if your water needs a filter?
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Find the Right Filter →Frequently Asked Questions
Is the tap water safe in Williamson County, Texas?
Williamson County has 34 community water systems with 283 recorded EPA violations, including 70 health-based. Water quality varies by ZIP code - check your specific location for detailed results.
How many water violations does Williamson County have?
Williamson County has 283 total EPA violations across 18 directly mapped ZIP records. 70 are health-based.
Which city in Williamson County has the most water violations?
Georgetown has the most violations in Williamson County with 53 recorded EPA violations across 3 ZIP codes.
What contaminants are found in Williamson County water?
Williamson County water systems are monitored for over 90 EPA-regulated contaminants including lead, copper, nitrates, disinfection byproducts, and bacteria. Check your ZIP code for contaminant-specific data.
How can I test my water in Williamson County?
Contact your local water utility for free or low-cost testing. You can also use a certified home test kit ($20-$50) or hire a certified lab ($150-$400).