Is San Antonio tap water safe to drink?
In the latest results, total trihalomethanes (86.2 ppb against 80 ppb) was above the federal limit (see the note in the table below). Lead was 1.6 ppb at the 90th percentile, below the 15 ppb action level. EPA’s goal for lead is zero. Lithium was found above EPA’s health reference level (10 ppb), a screening value that is not an enforceable limit. EPA lists no violations since 2016. See how US tap water compares nationally.
What’s in San Antonio tap water
Latest results from SAWS’s 2025 report and EPA records. One row per contaminant, with the type of limit in the limit column.
| Contaminant | Result | Limit | Sampled | Source |
|---|---|---|---|---|
| LeadComes mostly from home plumbing, not from the source water. | 1.6 ppb 90th percentile reported to EPA; previous round (Jul – Dec 2021): 2.3 ppb | 15 ppbAction level · goal 0Drops to 10 ppb on Nov 1, 2027 (Lead and Copper Rule Improvements). | 2022–2024 | EPA SDWIS record, TX0150018 |
| PFOA and PFOS (PFAS)Two “forever chemicals” with a federal limit. | Not detected 91 samples at 44 entry points; none at or above the reporting level (4 ppt) | 4.0 ppt eachLegal limit (MCL) · goal 0Utilities must comply from 2029; EPA proposed 2031 in May 2026. | May 2023 – Jun 2026 | EPA UCMR 5 final occurrence data (Aug 2026 release) |
| Other PFASFound among the 27 other PFAS EPA had utilities test. | 3 found PFBA up to 9.2 ppt; PFBS up to 3.8 ppt; PFPeA up to 3.2 ppt | VariesSet per compound in EPA’s PFAS rule | May 2023 – Jun 2026 | EPA UCMR 5 final occurrence data (Aug 2026 release) |
| Total trihalomethanesByproducts of disinfection. | 86.2 ppb Highest yearly average at one sampling location; range 0–86.2 As printed in the report, which lists no violation for this result and says SAWS received no violations in 2025. | 80 ppbLegal limit (MCL) | 2025 | SAWS 2026 Water Quality Report (2025 data) |
| Haloacetic acids (HAA5)Byproducts of disinfection. | 30.6 ppb Highest yearly average at one sampling location; range 0–30.6 | 60 ppbLegal limit (MCL) | 2025 | SAWS 2026 Water Quality Report (2025 data) |
| LithiumUnregulated; EPA is collecting national data. | Up to 25.5 ppb Found in 38 of 91 samples at 44 entry points; range 9–25.5 | 10 ppbEPA health reference levelA health reference level is a screening value, not an enforceable limit. | May 2023 – Jun 2026 | EPA UCMR 5 final occurrence data (Aug 2026 release) |
ppb = parts per billion (µg/L), ppt = parts per trillion (ng/L). The bar shows the result against the limit (black line). Limits: EPA drinking water regulations, PFAS rule, Lead and Copper Rule Improvements. “Not detected” means below the lab’s reporting level, not zero.
EPA violations
EPA’s SDWIS database lists 4 violation records for SAWS since 2012, none of them health-based. All have a return-to-compliance date.
Not listed: 4 older monitoring, reporting or notice records (2012–2016), none health-based.
Shown: health-based violations and everything from the last 10 years. Source: EPA SDWIS record, TX0150018, retrieved Oct 13, 2026.
How hard is San Antonio water?
SAWS’s 2025 water quality report does not list hardness. Hardness has no federal health limit. A test kit or a lab test measures it at your tap (see how to test water hardness).
What to do with these numbers
Only what the data above points to.
Lead comes from home plumbing
EPA’s goal for lead is zero. Older faucets, lead solder and lead service lines can add lead at your tap. A filter certified to NSF/ANSI 53 for lead reduces it.
Certified to reduce lead. Lead is not necessarily in your water.
All filters compared →Test your own water
SAWS’s numbers come from its own sampling sites. A certified lab test of your faucet shows lead and copper from your plumbing. How to test your own tap for lead, starting with your water utility.
All water tests compared →