Is there PFAS in San Leon MUD water?
Yes, at low levels. 4 PFAS were detected, all below EPA's 2024 limits.
San Leon MUD
Serves 11,622 people · 4 PFOA samples from 1 sampling point · Jul 2024 to Apr 2025
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: PFPeA, PFBA, PFHxA, PFBS.
San Leon MUD is a public water system drawing on surface water, based in San Leon, Texas, serving about 11,622 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 4 times across 1 sampling point between Jul 2024 and Apr 2025.
Every PFAS detected
Not detected: HFPO-DA, 8:2 FTS, 6:2 FTS, NMeFOSAA, NEtFOSAA, PFTrDA, PFTA, PFPeS, PFHpS, NFDHA, PFEESA, PFMBA, ADONA, PFMPA, PFNA, 4:2 FTS, PFHxS, 9Cl-PF3ONS, PFOS, PFOA, PFDA, PFDoA, PFUnA, 11Cl-PF3OUdS, PFHpA.
Lithium, tested in the same program: highest 17.5 ppb, detected in 3 of 4 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
77539
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 Leon MUD water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID TX0840063. https://wellandtap.com/pfas/texas/san-leon-mud/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID TX0840063). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
