Is there PFAS in San Antonio Water System water?
Yes, at low levels. 3 PFAS were detected, all below EPA's 2024 limits.
San Antonio Water System
Serves 2.6 million people · 91 PFOA samples from 44 sampling points · May 2023 to Jun 2026
PFAS found, below EPA limits
PFOA Perfluorooctanoic acid
not detected
PFOS Perfluorooctanesulfonic acid
not detected
Hazard index GenX, PFBS, PFNA, PFHxS combined
not detected
Also detected, no federal limit: PFBA, PFBS, PFPeA.
San Antonio Water System is a public water system drawing on surface water, based in San Antonio, Texas, serving about 2.6 million people, including Boerne, Helotes, Mico, Poteet, Somerset, Von Ormy. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 91 times across 44 sampling points between May 2023 and Jun 2026.
Every PFAS detected
Not detected: PFHpS, 8:2 FTS, PFMPA, PFMBA, PFEESA, 4:2 FTS, PFPeS, NMeFOSAA, PFTA, PFTrDA, NEtFOSAA, NFDHA, PFDA, PFHxS, PFHpA, 6:2 FTS, PFOA, PFNA, PFDoA, PFHxA, PFUnA, 11Cl-PF3OUdS, 9Cl-PF3ONS, ADONA, HFPO-DA, PFOS.
Lithium, tested in the same program: highest 25.5 ppb, detected in 38 of 91 samples. EPA's health-based screening level is 10 ppb.
What the EPA limits mean here
In April 2024 EPA set enforceable limits of 4 ppt for PFOA and PFOS, 10 ppt each for PFHxS, PFNA and GenX, and a hazard index of 1 for mixtures. Utilities were given until 2029 to comply. In May 2026 EPA proposed keeping only the PFOA and PFOS limits and moving that deadline to 2031. Until that proposal is final, the 2024 limits stand.
Compliance is judged on a running annual average at each entry point, so we show the average at this system's worst sampling point next to its single highest result. UCMR 5 results do not by themselves put a utility in or out of compliance.
What you can do at home
Levels here are under EPA's limits, so no treatment is required. If you want them lower anyway, a certified reverse osmosis system under the sink handles drinking water, and a whole-house carbon filter also takes out the chlorine or chloramine your utility adds.
Other systems in Texas
All 1154 tested systems in Texas
ZIP codes served
78006 78015 78023 78056 78065 78069 78073 78101 78109 78112 78154 78201 78202 78203 78204 78205 78207 78208 78209 78210 78211 78212 78213 78214 78215 78216 78217 78218 78219 78220 78221 78222 78223 78224 78225 78226 78227 78228 78229 78230 78231 78232 78233 78234 78235 78236 78237 78238 78239 78240 78242 78244 78245 78247 78248 78249 78250 78251 78252 78253 78254 78255 78256 78257 78258 78259 78260 78261 78263 78264 78266 78284 78288
As reported by the utility to EPA. Neighbouring ZIPs are often split between systems; your water bill names yours.
Cite this page
Well & Tap. "PFAS in San Antonio Water System water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID TX0150018. https://wellandtap.com/pfas/texas/san-antonio-water-system/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID TX0150018). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
