Water Quality Report · Updated October 07, 2026
San Antonio Department of Public Works
San Antonio Department of Public Works delivers tap water graded A (86/100) by TapWaterSafety.org. The utility serves approximately 1,547,000 residents in San Antonio, Texas using groundwater from the Edwards Aquifer. The most significant water quality concerns are: Arsenic significantly above health guideline. For questions, the utility can be reached at (713) 962-3087.
Is San Antonio tap water safe to drink?
San Antonio Department of Public Works delivers tap water that earns a grade of A (86/100) from TapWaterSafety.org — an excellent rating reflecting minimal contamination and full compliance with health guidelines.
The utility serves 1,547,000 residents in San Antonio, drawing from groundwater (Edwards Aquifer) and disinfecting with chloramine.
Public testing data identifies 12 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Arsenic, Arsenic, Haloacetic Acids (HAA5), Haloacetic Acids (HAA5), Total Trihalomethanes (TTHMs), Total Trihalomethanes (TTHMs), Haloacetic Acids (HAA5), Nitrate, Total Trihalomethanes (TTHMs), Nitrate, Nitrate. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for San Antonio residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for San Antonio Department of Public Works.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 4.6 ppb, 1150x above the EWG health guideline of 0.004 ppb.
Contact San Antonio Department of Public Works
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Water Quality Contact
For questions about contaminants, test results, or your Consumer Confidence Report.
Treatment Plant
Recommended water filters for San Antonio
Filters matched to the specific contaminants in this water supply.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 86/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). 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 |
| Arsenic Heavy metal |
3.62 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2023 | 905× over |
| Arsenic Heavy metal |
3.58 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2022 | 895× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
3.77 ppb | 0.1 | 60 | 60 | — | — | 2022 | 38× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
3.1 ppb | 0.1 | 60 | 60 | — | — | 2024 | 31× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
17.2 ppb | 0.6 | 80 | 100 | — | — | 2022 | 29× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
13.9 ppb | 0.6 | 80 | 100 | — | — | 2024 | 23× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
2.18 ppb | 0.1 | 60 | 60 | — | — | 2023 | 22× over |
| Nitrate Inorganic |
2.6 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2024 | 19× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
11.0 ppb | 0.6 | 80 | 100 | — | — | 2023 | 18× over |
| Nitrate Inorganic |
2.21 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2023 | 16× over |
| Nitrate Inorganic |
2.09 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2022 | 15× over |
| Contaminant | Detected (2024) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
13.9 ppb | 0.6 | 80 | 100 | — | — | 23× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
3.1 ppb | 0.1 | 60 | 60 | — | — | 31× over |
| 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 (2023) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
11.0 ppb | 0.6 | 80 | 100 | — | — | 18× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
2.18 ppb | 0.1 | 60 | 60 | — | — | 22× over |
| Arsenic Heavy metal |
3.62 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 905× over |
| Nitrate Inorganic |
2.21 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 16× over |
| Contaminant | Detected (2022) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
17.2 ppb | 0.6 | 80 | 100 | — | — | 29× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
3.77 ppb | 0.1 | 60 | 60 | — | — | 38× over |
| Arsenic Heavy metal |
3.58 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 895× over |
| Nitrate Inorganic |
2.09 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 15× 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database, and San Antonio Department of Public Works's Consumer Confidence Report.
San Antonio Department of Public Works service area
This water system serves 1 community in Bexar County, Texas. Click any city for its dedicated tap water quality page.
Find the right filter for San Antonio water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.