Water Quality in Houston, TX: 1183 Violations Recorded for Mapped Water Systems
154 water systems · 97 directly mapped ZIP records
Available EPA records report 1183 violations across 97 directly mapped ZIP records with known counts for Houston. 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 Houston
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 77090 | 374 | 3 | View report → |
| 77060 | 240 | 6 | View report → |
| 77049 | 122 | 2 | View report → |
| 77053 | 75 | 2 | View report → |
| 77083 | 50 | 3 | View report → |
| 77044 | 41 | 2 | View report → |
| 77065 | 41 | 3 | View report → |
| 77041 | 38 | 4 | View report → |
| 77064 | 30 | 3 | View report → |
| 77073 | 28 | 1 | View report → |
| 77070 | 26 | 1 | View report → |
| 77066 | 22 | 1 | View report → |
| 77014 | 21 | 1 | View report → |
| 77015 | 18 | 2 | View report → |
| 77038 | 18 | 1 | View report → |
Water Quality Overview
Houston, Texas has directly mapped EPA water-system data for 97 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 1183 violations, including 31 health-based violations across 97 directly mapped ZIP records with reported counts.
Lead Levels
The average of the reported 90th-percentile lead results across the ZIP codes of Houston is 0.0049 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 97 ZIP records with known lead status.
With 56% of homes built before 1986, Houston has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Water Systems Serving Houston
Houston is served by 154 community water systems regulated under the Safe Drinking Water Act. About 3,206,570 people live in the area (190 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 enforcement actions against water systems serving Houston. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Houston
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 Houston Water Systems
The following contaminants have been detected or caused violations across Houston's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Public Notice Rule | Reporting | N/A | 237 | 37 | No |
| Interim Enhanced Surface Water Treatment Rule | Treatment Technique | N/A | 93 | 93 | Yes |
| Lead and Copper Rule | Treatment Technique | N/A | 92 | 36 | Yes |
| Lead and Copper Rule Revisions | Treatment Technique | N/A | 84 | 29 | Yes |
| Consumer Confidence Rule | Reporting | N/A | 72 | 28 | No |
| Chlorine | Disinfectant | 4 mg/L (MRDL) | 49 | 15 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 25 | 14 | Yes |
| Nitrate | Inorganic | 10 mg/L | 25 | 6 | No |
| 1,2,4-Trichlorobenzene | Organic | N/A | 22 | 6 | No |
| cis-1,2-Dichloroethylene | Organic | N/A | 22 | 6 | No |
| Xylenes, Total | Organic | N/A | 22 | 6 | No |
| Dichloromethane | Organic | N/A | 22 | 6 | No |
| o-Dichlorobenzene | Organic | N/A | 22 | 6 | No |
| p-Dichlorobenzene | Organic | N/A | 22 | 6 | No |
| Vinyl chloride | Organic | N/A | 22 | 6 | 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 health-based EPA violations recorded for water systems serving Houston (this history covers health-based records only):
| Year | Health-based violations |
|---|---|
| 2021 | 2 |
| 2022 | 2 |
| 2024 | 8 |
| 2025 | 84 |
| 2026 | 7 |
Health-based violations have increased from 2 in 2021 to 7 in 2026. This trend warrants monitoring.
EPA Enforcement History
The EPA and state regulators have taken enforcement actions against water systems serving Houston. Recent actions:
| Date | Action Type |
|---|---|
| 2026-06-16 | State Order Extension |
| 2026-06-12 | State Order Extension |
| 2026-06-10 | State Informal Action |
| 2026-06-10 | State Informal Enforcement |
| 2026-06-10 | State Order Extension |
| 2026-06-09 | State Informal Action |
| 2026-06-09 | State Order Extension |
| 2026-06-08 | State Order Extension |
| 2026-06-04 | State Order Extension |
| 2026-06-02 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2026-06-16.
Houston vs. Nearby Texas Cities
How Houston's water quality compares to similar cities in Texas:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Houston | 97 | 1183 | 154 | 3,206,570 |
| San Antonio | 60 | 337 | 36 | 1,860,461 |
| Dallas | 49 | 30 | 18 | 1,372,181 |
| Austin | 44 | 138 | 46 | 1,157,348 |
Water Quality by ZIP Code in Houston
EPA coverage and recorded violations can differ across Houston's ZIP codes. Missing counts are shown as unavailable, not zero:
| ZIP Code | Violations | Health-Based |
|---|---|---|
| 77090 | 374 | 3 |
| 77060 | 240 | 6 |
| 77049 | 122 | 2 |
| 77053 | 75 | 2 |
| 77083 | 50 | 3 |
| 77044 | 41 | 2 |
| 77065 | 41 | 3 |
| 77041 | 38 | 4 |
| 77064 | 30 | 3 |
| 77073 | 28 | 1 |
| 77070 | 26 | 1 |
| 77066 | 22 | 1 |
| 77014 | 21 | 1 |
| 77015 | 18 | 2 |
| 77038 | 18 | 1 |
Common Questions About Houston Water
These are the most common questions residents search for about water quality in Houston, Texas:
Is Houston water hard or soft? Water hardness varies by source. Houston's 154 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Houston tap water? City-level EPA records cannot determine safety at a specific tap. The measured subset contains 31 health-based violations; check the affected utility record and consider certified testing.
What is the best water filter for Houston? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Houston vs. Texas Average
Understanding how Houston 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 Houston.
ZIP Codes in Houston
Houston spans 190 ZIP codes. EPA water-system coverage is available for 97 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.