Is there PFAS in Sonterra MUD water?
Yes, at low levels. 4 PFAS were detected, all below EPA's 2024 limits.
Sonterra MUD
Serves 16,614 people · 6 PFOA samples from 3 sampling points · Apr 2024 to Oct 2024
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, PFBS, PFBA, PFHxA.
Sonterra MUD is a public water system drawing on surface water, based in Austin, Texas, serving about 16,614 people, including Jarrell, Georgetown. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 6 times across 3 sampling points between Apr 2024 and Oct 2024.
Every PFAS detected
Not detected: PFHpA, 9Cl-PF3ONS, PFUnA, PFDoA, PFDA, PFOA, PFOS, PFNA, PFMBA, 11Cl-PF3OUdS, ADONA, PFHxS, PFTrDA, HFPO-DA, NEtFOSAA, PFTA, PFHpS, PFPeS, PFMPA, 8:2 FTS, 4:2 FTS, NFDHA, 6:2 FTS, PFEESA, NMeFOSAA.
Lithium, tested in the same program: highest 23.3 ppb, detected in 5 of 6 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
76537 78626 78633
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 Sonterra MUD water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID TX2460157. https://wellandtap.com/pfas/texas/sonterra-mud/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID TX2460157). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
