Drinking water quality · 2023
· Verified
What's in San Antonio, TX tap water
16 contaminants were measured in the San Antonio, TX water system's 2023 annual report. Each is shown below against its federal limit.
- Reporting year
- 2023
- Contaminants measured
- 16
- Over federal limit
- 0
- Approaching the limit
- 1
- Service area
- TX
PFAS — EPA UCMR5 (2023–2025)
3 PFAS compounds detected in San Antonio, TX
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFBA
● Detected (no federal limit)PFPeA
● Detected (no federal limit)PFBS
● Detected (no federal limit)Where your water comes from · EPA SDWIS
San Antonio, TX's drinking water comes from ground water, drawn from 181 sources.
Source
- ASR · 29
- MISSION · 8
- NACO · 7
- BASIN · 6
- + 93 more
Treatment
- PLANT - FAC 1 / 411 CARLISLE (SOUTHSIDE)
- PLANT - FAC 5 6019 ZARZAMORA (SOUTHSIDE)
- PLANT - 3019 LA ROSA (SOUTHSIDE)
- + 61 more
Distribution
Also buys water from GBRA WESTERN CANYON WATER SUPPLY, WATER EXPLORATION STEIN ROGER WELL FIELD, and 4 more.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based1 violation on record · most recent Dec 2005resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.15–3.31 mg/LRangeConcentration Range Found | 4 mg/LMCLG | Approaching the limit |
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 2.51 mg/LReported levelSystem-wide | 10 mg/LMCLG | Within the limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 0–52.9 ug/LRangeRange of Individual Samples | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 0–19.4 ug/LRangeRange of Individual Samples | None set | Within the limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 6.2 pCi/LHighest single sampleSystem-wide | 0 pCi/LMCLG | Within the limit |
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | 1.82 pCi/LHighest single sampleSystem-wide | 0 pCi/LMCLG | Within the limit |
| Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances. | 5.5 pCi/LHighest single sampleSystem-wide | 0 pCi/LMCLG | Detected — no federal limit |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chlorine Free | 1.47 mg/LAverageSystem-wide | 4 mg/LMCL | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.206 mg/L90th percentileAt the tap | 1.3 mg/LMCLG | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 2.25 ug/L90th percentileAt the tap | 0 ug/LMCLG | Within the limit |
| SeleniumA trace element from natural deposits and industrial discharge. | 4.2 ug/LReported levelSystem-wide | None set | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.0945 mg/LReported levelSystem-wide | 2 mg/LMCLG | Within the limit |
| LithiumA naturally occurring element found in some groundwater. | 12.82 ug/LAverageSystem-wide | None set | Detected — no federal limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0.5MaximumNo. of Positive | 0MCLG | Detected — no federal limit |
+By source (2)— No. of Positive, Total No. of Positive E. Coli or Fecal
| |||
People also ask about San Antonio, TX's water
+Is San Antonio, TX tap water safe to drink in 2023?
Every one of the 16 contaminants measured in San Antonio, TX's 2023 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in San Antonio, TX tap water?
16 contaminants were measured in San Antonio, TX's 2023 Consumer Confidence Report, spanning metals, radionuclides, and disinfection byproducts. 10 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Are any contaminants in San Antonio, TX tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: Fluoride. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from San Antonio, TX's 2023 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is San Antonio, TX's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2023 report; a new report will replace it once the utility publishes its next annual update.