Tap Water Quality Report
Tap water quality in San Antonio, Texas
Tap water in San Antonio, Texas receives a grade of C (76/100) from TapWaterSafety.org. It's served by San Antonio Department of Public Works. The most significant water quality concerns are: Arsenic significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database, and San Antonio's published Consumer Confidence Report.
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.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 4.6 ppb, 1150x above the EWG health guideline of 0.004 ppb.
Recommended filters for San Antonio
Filters matched to the specific contaminants in San Antonio's water supply.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
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 |
|---|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
4.6 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2024 | 1150× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
3.77 ppb | 0.1 | 60 | 60 | — | — | 2022 | 38× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
17.2 ppb | 0.6 | 80 | 100 | — | — | 2022 | 29× over |
| Nitrate Inorganic |
2.6 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2024 | 19× over |
| Contaminant | Detected (2024) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
4.6 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 1150× over |
| Nitrate Inorganic |
2.6 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 19× over |
| Contaminant | Detected (2022) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) Disinfection byproduct |
3.77 ppb | 0.1 | 60 | 60 | — | — | 38× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
17.2 ppb | 0.6 | 80 | 100 | — | — | 29× over |
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 Department of Public Works.
General Contact
Water Quality Contact
For questions about contaminants or test results.