Water Quality in San Antonio, TX: 172 Violations — Grade A
Grade A · Score 92/100 · 5 water systems · Updated 2026-05-03
San Antonio's water meets all EPA standards with no health-based violations.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
According to EPA filings, San Antonio, TX has 172 water compliance violations on record — sourced from SDWIS, the federal database that tracks reportable events for every registered public water system in the state.
Water Quality Map: San Antonio, TX
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in San Antonio
Water quality varies across San Antonio's 86 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 78209 | B | 79 | 2 | 1 | View report → |
| 78201 | B | 84 | 2 | 1 | View report → |
| 78212 | B | 84 | 2 | 1 | View report → |
| 78213 | B | 84 | 2 | 1 | View report → |
| 78216 | B | 84 | 2 | 1 | View report → |
| 78217 | B | 84 | 2 | 1 | View report → |
| 78218 | B | 84 | 2 | 1 | View report → |
| 78227 | B | 84 | 2 | 1 | View report → |
| 78228 | B | 84 | 2 | 1 | View report → |
| 78230 | B | 84 | 2 | 1 | View report → |
| 78232 | B | 84 | 2 | 1 | View report → |
| 78238 | B | 84 | 2 | 1 | View report → |
| 78205 | A | 89 | 2 | 1 | View report → |
| 78207 | A | 89 | 2 | 1 | View report → |
| 78210 | A | 89 | 2 | 1 | View report → |
Violation Trend
EPA violations recorded for water systems serving San Antonio.
Water Quality Overview
San Antonio, Texas receives a water quality grade of A with an overall score of 92 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving San Antonio have accumulated 172 EPA violations, including 86 health-based violations. These violations are tracked across 86 ZIP codes serving approximately 2,170,211 people.
What Grade A Means
A grade of A indicates excellent compliance with EPA drinking water standards. San Antonio's water systems have maintained strong performance in both contaminant monitoring and regulatory compliance.
Lead Levels
The average 90th percentile lead level across San Antonio water systems is 0.0016 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
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 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 2,170,211 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 860 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, violation history, and safety scores
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 |
|---|---|---|---|---|---|
| Stage 1 DBP Rule | Treatment Technique | N/A | 86 | 86 | Yes |
| Total Coliform | Microbiological | N/A | 86 | 86 | 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 |
|---|---|---|
| 2023 | 86 | 86 |
| 2024 | 86 | 86 |
Violation counts have remained stable over the observed period.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving San Antonio. Recent actions:
| Date | Action Type |
|---|---|
| 2025-08-04 | State Order Extension |
| 2025-08-04 | State Informal Action |
| 2025-05-28 | State Informal Action |
| 2025-05-27 | State Informal Action |
| 2025-05-20 | State Informal Enforcement |
| 2025-04-15 | State Order Extension |
| 2025-04-07 | State Informal Action |
| 2025-03-31 | State Informal Action |
| 2025-03-31 | State Informal Enforcement |
| 2024-04-29 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-08-04.
San Antonio vs. Nearby Texas Cities
How San Antonio's water quality compares to similar cities in Texas:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| San Antonio | A | 172 | 5 | 2,170,211 |
| Lackland A F B | C | 0 | 1 | 2,113,151 |
| Macdona | C | 0 | 1 | 2,113,151 |
| Rio Medina | B | 0 | 1 | 2,113,151 |
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
Water quality varies across San Antonio's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
| ZIP Code | Score | Grade | Violations | Health-Based |
|---|---|---|---|---|
| 78209 | 79 | B | 2 | 1 |
| 78201 | 84 | B | 2 | 1 |
| 78212 | 84 | B | 2 | 1 |
| 78213 | 84 | B | 2 | 1 |
| 78216 | 84 | B | 2 | 1 |
| 78217 | 84 | B | 2 | 1 |
| 78218 | 84 | B | 2 | 1 |
| 78227 | 84 | B | 2 | 1 |
| 78228 | 84 | B | 2 | 1 |
| 78230 | 84 | B | 2 | 1 |
| 78299 | 98 | A | 2 | 1 |
| 78298 | 98 | A | 2 | 1 |
| 78297 | 98 | A | 2 | 1 |
| 78296 | 98 | A | 2 | 1 |
| 78295 | 98 | A | 2 | 1 |
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 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink San Antonio tap water? San Antonio's water receives a grade of A (92/100). There are 86 health-based violations — consider filtration.
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. The ZIP with the lowest water quality score is 78201. Each ZIP code has its own water quality profile based on the specific water system serving that area. 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
Updated daily.
Frequently Asked Questions
Your Water is Safe — Here's How to Keep It That Way
Grade A is excellent news. Here's what proactive homeowners do to maintain water quality:
Annual Water Testing
EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.
Maintenance Filtration
A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.
Plumbing Check
Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.