Water Quality in Round Rock, TX: 46 Violations Recorded for Mapped Water Systems
13 water systems · 3 directly mapped ZIP records
Available EPA records report 46 violations across 3 directly mapped ZIP records with known counts for Round Rock. This is compliance evidence, not a property-level tap-water verdict.
Data: EPA Safe Drinking Water Information System (SDWIS)
Water Quality by ZIP Code in Round Rock
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 78681 | 26 | 3 | View report → |
| 78664 | 17 | 8 | View report → |
| 78665 | 9 | 1 | View report → |
Violation Trend
EPA violations recorded for water systems serving Round Rock.
| Year | Total violations | Health-based |
|---|---|---|
| 2025 | 4 | 4 |
| 2026 | 1 | 1 |
Water Quality Overview
Round Rock, Texas has directly mapped EPA water-system data for 3 ZIP codes. This page reports typed compliance facts and does not relabel the multi-source Home Safety Score as a drinking-water grade.
The available EPA records report 46 violations, including 10 health-based violations across 3 directly mapped ZIP records with reported counts.
Lead Levels
The average of the reported 90th-percentile lead results across the ZIP codes of Round Rock is 0.0051 mg/L; the EPA action level of 0.015 mg/L applies to a water system's own 90th-percentile result and is not a safety threshold (EPA's health goal for lead is zero). No exceedances appear among the 3 ZIP records with known lead status.
Water Systems Serving Round Rock
Round Rock is served by 13 community water systems regulated under the Safe Drinking Water Act. About 184,890 people live in the area (6 ZIP codes, Census); this is not the systems' reported service population.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
EPA records list 30 enforcement actions against water systems serving Round Rock. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Round Rock
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels and violation history
Request your CCR - your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test - certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration - NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories - monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Round Rock Water Systems
The following contaminants have been detected or caused violations across Round Rock's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 11 | 3 | Yes |
| Revised Total Coliform Rule | Microbiological | N/A | 8 | 3 | No |
| Lead and Copper Rule | Treatment Technique | N/A | 8 | 3 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 8 | 1 | No |
| Total Coliform | Microbiological | N/A | 4 | 2 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 3 | 1 | Yes |
| Fecal Coliform | Microbiological | N/A | 2 | 2 | Yes |
| Surface Water Treatment Rule | Treatment Technique | N/A | 2 | 1 | No |
| Lead | Inorganic | 0.015 mg/L | 1 | 1 | No |
| Copper | Inorganic | 1.3 mg/L | 1 | 1 | No |
The standard column shows the EPA Maximum Contaminant Level (MCL) except for lead and copper, whose value is an action level that triggers corrective steps and is not an MCL. Health-based violations are MCL, MRDL and treatment-technique violations.
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving Round Rock:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2025 | 4 | 4 |
| 2026 | 1 | 1 |
Violations have decreased from 4 in 2025 to 1 in 2026, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 25 enforcement actions against water systems serving Round Rock. Recent actions:
| Date | Action Type |
|---|---|
| 2026-06-01 | State Informal Action |
| 2026-06-01 | State Informal Enforcement |
| 2026-04-17 | State Order Extension |
| 2026-04-16 | State Informal Action |
| 2026-04-16 | State Informal Enforcement |
| 2026-03-26 | State Order Extension |
| 2026-03-24 | State Order Extension |
| 2026-03-24 | State Informal Action |
| 2026-03-16 | State Informal Action |
| 2026-01-20 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2026-06-01.
Round Rock vs. Nearby Texas Cities
How Round Rock's water quality compares to similar cities in Texas:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Round Rock | 3 | 46 | 13 | 184,890 |
| Mission | 3 | 85 | 7 | 183,923 |
| Frisco | 3 | 11 | 5 | 187,486 |
| Humble | 3 | 38 | 12 | 181,805 |
Recommended Water Filters for Round Rock
Based on contaminants detected in Round Rock's water supply, these filter types are recommended:
Granular Activated Carbon (GAC, whole-house or under-sink)
- Removes: Chlorine
- Effectiveness: 95-99%
- Cost range: $100–$600
- Certification: NSF/ANSI 42
- Recommended products:
- Aquasana AQ-5200
- Waterdrop Chubby Pitcher
- Berkey Travel
Granular Activated Carbon (GAC, whole-house POE)
- Removes: Trihalomethane (TTHM)
- Effectiveness: 80-99%
- Cost range: $400–$2000
- Certification: NSF/ANSI 53
- Recommended products:
Water Quality by ZIP Code in Round Rock
EPA coverage and recorded violations can differ across Round Rock's ZIP codes. Missing counts are shown as unavailable, not zero:
Common Questions About Round Rock Water
These are the most common questions residents search for about water quality in Round Rock, Texas:
Is Round Rock water hard or soft? Water hardness varies by source. Round Rock's 13 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Round Rock tap water? City-level EPA records cannot determine safety at a specific tap. The measured subset contains 10 health-based violations; check the affected utility record and consider certified testing.
What is the best water filter for Round Rock? Based on detected contaminants, a granular activated carbon (gac, whole-house or under-sink) filter is most recommended. See our Water Filter Matcher for personalized recommendations.
Round Rock vs. Texas Average
Understanding how Round Rock compares to the broader Texas average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below - water quality can vary significantly even within Round Rock.
ZIP Codes in Round Rock
Round Rock spans 6 ZIP codes. EPA water-system coverage is available for 3 directly mapped ZIP codes. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Source reporting periods vary. See each cited source for its publication schedule.