Drinking water quality · 2023
· Verified
· PWSID TX0150018
What's in San Antonio, TX tap water
Every one of the 11 core regulated contaminants reported for San Antonio, TX came in below its federal limit.
- !1 contaminant within 20% of a limit
- !11 of 27 core regulated contaminants reported — 16 never appear in this report
- ✓Nothing over a federal limit
- ✓No open federal violations
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −0 contaminants at or above a federal limit
- −4 contaminants within 20% of a limit
- −0 open health-based violations
- −0 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −13 core regulated contaminants never reported (11/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →What to worry about
- Fluoride83% of the federal limit0.15–3.31 mg/L · limit 4 mg/L
Beneficial at low levels, but long-term exposure above the federal limit can cause bone disease and tooth mottling.
higher than 95% of U.S. systems
+16 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| TTHM | 0–52.9 ug/L | 80 ug/L |
| Gross Alpha | 6.2 pCi/L | 15 pCi/L |
| Chlorine Free | 1.47 mg/L | 4 mg/L |
| Combined Radium | 1.82 pCi/L | 5 pCi/L |
| HAA5 | 0–19.4 ug/L | 60 ug/L |
| Nitrate | 2.51 mg/L | 10 mg/L |
| Copper | 0.206 mg/L | 1.3 mg/L |
| Lead | 2.25 ug/L | 15 ug/L |
| Selenium | 4.2 ug/L | 50 ug/L |
| Barium | 0.0945 mg/L | 2 mg/L |
| Lithium | 12.82 ug/L | — |
| Total Coliform | 0.5 | 0 |
| Gross Beta Particle Activity | 5.5 pCi/L | 0 pCi/L |
| PFBA | 9.2 ng/L | — |
| PFPeA | 3.2 ng/L | — |
| PFBS | 3.8 ng/L | — |
What this report doesn't tell you
16 of the 27 contaminants a community water system normally reports do not appear anywhere in San Antonio, TX's data. Absent is not the same as absent-from-the-water — it means nobody published a number.
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record
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 ↗