Tap Water Quality Report
Tap water quality in San Antonio, Texas
Tap water in San Antonio, Texas receives a grade of C (75/100) from TapWaterSafety.org. It's served by SAN ANTONIO WATER SYSTEM. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Bromochloroacetic acid significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in San Antonio's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving San Antonio.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 9.67 ppb, 161x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 22.9 ppb, 152x above the EWG health guideline of 0.15 ppb.
Bromochloroacetic acid significantly above health guideline
Moderate concernBromochloroacetic acid detected at 2.12 ppb, 106x above the EWG health guideline of 0.02 ppb.
EPA compliance record
Official U.S. EPA records for SAN ANTONIO WATER SYSTEM (system ID TX0150018) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for San Antonio
Filters matched to the specific contaminants in San Antonio's water supply.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in San Antonio's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
9.67 ppb | 0.06 | — | — | — | — | — | 161× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
22.9 ppb | 0.15 | 80.0 | 100 | — | — | — | 152× over |
| Bromochloroacetic acid Disinfection byproduct |
2.12 ppb | 0.02 | — | — | — | — | — | 106× over |
| Dibromoacetic acid Disinfection byproduct |
2.41 ppb | 0.03 | — | — | — | — | — | 80× over |
| Bromodichloromethane Disinfection byproduct |
4.42 ppb | 0.06 | — | — | — | — | — | 74× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
5.76 ppb | 0.1 | 60.0 | 60 | — | — | — | 58× over |
| Dibromochloromethane Disinfection byproduct |
5.55 ppb | 0.1 | — | — | — | — | — | 55× over |
| Nitrate and nitrite Inorganic |
2.01 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 14× over |
| Dichloroacetic acid Disinfection byproduct |
2.05 ppb | 0.2 | — | — | — | — | — | 10× over |
| Nitrate Inorganic |
1.42 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 10× over |
| Chloroform Disinfection byproduct |
2.82 ppb | 0.4 | — | — | — | — | — | 7.0× over |
| Chromium (hexavalent) Heavy metal |
0.136 ppb | 0.02 | — | — | — | — | — | 6.8× over |
| Radium, combined (-226 and -228) Radiological |
0.34 pCi/L | 0.05 | 5.0 | — | — | — | — | 6.8× over |
| Bromoform Disinfection byproduct |
2.95 ppb | 0.5 | — | — | — | — | — | 5.9× over |
| Trichloroacetic acid Disinfection byproduct |
0.428 ppb | 0.1 | — | — | — | — | — | 4.3× over |
| Thallium Heavy metal |
0.05 ppb | 0.1 | 2.0 | — | — | — | — | Below guideline |
| Uranium Radiological |
0.14 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | Below guideline |
| Vanadium Other |
2.72 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
62.0 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Chlorate Disinfection byproduct |
6.27 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
1.04 ppb | 40.0 | — | — | — | — | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.00829 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Selenium Heavy metal |
0.1 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Manganese Heavy metal |
0.299 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.0921 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.0277 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.806 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
0.536 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Cobalt Other |
0.0069 ppb | 70.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
0.076 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.088 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Xylenes (total) Volatile organic compound |
0.0123 ppb | 1800.0 | 10000.0 | — | — | — | — | Below guideline |
| 2-methyl-1-propene Other |
5.0 ppb | — | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
0.243 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.426 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Hexadecanoic acid Other |
3.91 ppb | — | — | — | — | — | — | Below guideline |
| Lithium Other |
9.45 ppb | — | — | — | — | — | — | Below guideline |
| Octadecanoic acid Other |
6.15 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from SAN ANTONIO WATER SYSTEM.
General Contact
Treatment Plant
ZIP codes served
San Antonio's public water systems serve the following ZIP codes: