Water Quality in San Antonio, TX: 337 Violations - Grade N/A
36 water systems · 60 directly mapped ZIP records
Available EPA records report 337 violations across 60 directly mapped ZIP records with known counts for San Antonio. 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 San Antonio
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 78266 | 169 | 58 | View report → |
| 78245 | 55 | 13 | View report → |
| 78238 | 43 | 0 | View report → |
| 78240 | 43 | 0 | View report → |
| 78250 | 43 | 0 | View report → |
| 78264 | 31 | 12 | View report → |
| 78224 | 30 | 12 | View report → |
| 78252 | 30 | 12 | View report → |
| 78249 | 24 | 5 | View report → |
| 78219 | 11 | 1 | View report → |
| 78223 | 10 | 0 | View report → |
| 78253 | 10 | 1 | View report → |
| 78209 | 8 | 2 | View report → |
| 78213 | 8 | 4 | View report → |
| 78230 | 8 | 4 | View report → |
Violation Trend
EPA violations recorded for water systems serving San Antonio.
| Year | Total violations | Health-based |
|---|---|---|
| 2021 | 22 | 22 |
| 2022 | 28 | 28 |
| 2023 | 23 | 23 |
| 2024 | 28 | 28 |
| 2025 | 16 | 16 |
| 2026 | 1 | 1 |
Water Quality Overview
San Antonio, Texas has directly mapped EPA water-system data for 60 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 337 violations, including 80 health-based violations across 60 directly mapped ZIP records with reported counts.
Lead Levels
The average 90th percentile lead level across San Antonio water systems is 0.0018 mg/L - within EPA limits. No exceedances appear among the 60 ZIP records with known lead status.
With 49% of homes built before 1986, San Antonio 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 San Antonio
San Antonio is served by 36 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 1,860,461 people across 86 ZIP codes.
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
The EPA has taken 450 enforcement actions against water systems serving San Antonio. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in San Antonio
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 San Antonio Water Systems
The following contaminants have been detected or caused violations across San Antonio's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Lead and Copper Rule | Treatment Technique | N/A | 108 | 16 | No |
| Fecal Coliform | Microbiological | N/A | 53 | 1 | No |
| Gross Alpha | Radionuclides | 15 pCi/L | 48 | 4 | Yes |
| Revised Total Coliform Rule | Microbiological | N/A | 35 | 9 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 28 | 16 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 27 | 16 | Yes |
| Stage 2 DBP Rule | Treatment Technique | N/A | 26 | 16 | Yes |
| Total Coliform | Microbiological | N/A | 18 | 12 | No |
| Uranium | Radionuclides | 0.03 mg/L | 16 | 4 | Yes |
| PFOA | PFAS | 0.000004 mg/L | 6 | 3 | No |
| PFNA | PFAS | 0.00001 mg/L | 6 | 3 | No |
| Monochloroacetic Acid | Disinfection Byproducts | 0.06 mg/L | 6 | 3 | No |
| Dichloroacetic Acid | Disinfection Byproducts | 0.06 mg/L | 6 | 3 | No |
| Bromodichloromethane | Disinfection Byproducts | 0.08 mg/L | 6 | 3 | No |
| Dibromochloromethane | Disinfection Byproducts | 0.08 mg/L | 6 | 3 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving San Antonio:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 22 | 22 |
| 2022 | 28 | 28 |
| 2023 | 23 | 23 |
| 2024 | 28 | 28 |
| 2025 | 16 | 16 |
| 2026 | 1 | 1 |
Violations have decreased from 22 in 2021 to 1 in 2026, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 87 enforcement actions against water systems serving San Antonio. Recent actions:
| Date | Action Type |
|---|---|
| 2026-06-19 | State Informal Action |
| 2026-06-16 | State Informal Action |
| 2026-06-12 | State Informal Enforcement |
| 2026-06-03 | State Order Extension |
| 2026-06-03 | State Informal Action |
| 2026-05-29 | State Informal Action |
| 2026-05-27 | State Informal Action |
| 2026-05-19 | State Informal Action |
| 2026-05-12 | State Informal Action |
| 2026-05-11 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2026-06-19.
San Antonio vs. Nearby Texas Cities
How San Antonio's water quality compares to similar cities in Texas:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| San Antonio | 60 | 337 | 36 | 1,860,461 |
| Dallas | 49 | 30 | 18 | 1,372,181 |
| Austin | 44 | 138 | 46 | 1,157,348 |
| Fort Worth | 32 | 334 | 37 | 982,017 |
Recommended Water Filters for San Antonio
Based on contaminants detected in San Antonio's water supply, these filter types are recommended:
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 San Antonio
EPA coverage and recorded violations can differ across San Antonio's ZIP codes. Missing counts are shown as unavailable, not zero:
| ZIP Code | Violations | Health-Based |
|---|---|---|
| 78266 | 169 | 58 |
| 78245 | 55 | 13 |
| 78238 | 43 | 0 |
| 78240 | 43 | 0 |
| 78250 | 43 | 0 |
| 78264 | 31 | 12 |
| 78224 | 30 | 12 |
| 78252 | 30 | 12 |
| 78249 | 24 | 5 |
| 78219 | 11 | 1 |
| 78223 | 10 | 0 |
| 78253 | 10 | 1 |
| 78209 | 8 | 2 |
| 78213 | 8 | 4 |
| 78230 | 8 | 4 |
Common Questions About San Antonio Water
These are the most common questions residents search for about water quality in San Antonio, Texas:
Is San Antonio water hard or soft? Water hardness varies by source. San Antonio's 36 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink San Antonio tap water? City-level EPA records cannot determine safety at a specific tap. The measured subset contains 80 health-based violations; check the affected utility record and consider certified testing.
What is the best water filter for San Antonio? Based on detected contaminants, a granular activated carbon (gac, whole-house poe) filter is most recommended. See our Water Filter Matcher for personalized recommendations.
San Antonio vs. Texas Average
Understanding how San Antonio 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 San Antonio.
ZIP Codes in San Antonio
San Antonio spans 86 ZIP codes. EPA water-system coverage is available for 60 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.