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Is there PFAS in Compton-city, Water Dept. water?

Yes. EPA's final UCMR 5 results show Compton-city, Water Dept. averaged 15.5 ppt of PFOS at its worst sampling point, 3.9 times the EPA limit of 4 ppt.

Compton-city, Water Dept. Serves 74,877 people · 13 PFOA samples from 6 sampling points · Sep 2023 to May 2024 Average above an EPA limit
PFOA Perfluorooctanoic acid 2.4 ppt avg · max 4.9
EPA 4
PFOS Perfluorooctanesulfonic acid 15.5 ppt avg · max 17.0
EPA 4
PFHxS Perfluorohexanesulfonic acid 4.1 ppt avg
EPA 10
Hazard index GenX, PFBS, PFNA, PFHxS combined 0.4 avg
EPA 1
Averages are for the worst sampling point, with non-detects counted as zero. Source: EPA UCMR 5.

Compton-city, Water Dept. is a public water system drawing on surface water, based in Compton, California, serving about 74,877 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 13 times across 6 sampling points between Sep 2023 and May 2024.

Every PFAS detected

PFAS Detected Highest Worst point avg EPA limit
PFOS
Perfluorooctanesulfonic acid
2 of 13 17.0 ppt 15.5 ppt 4 ppt
PFOA
Perfluorooctanoic acid
1 of 13 4.9 ppt 2.4 ppt 4 ppt
PFHxS
Perfluorohexanesulfonic acid
2 of 13 4.1 ppt 4.1 ppt 10 ppt

Not detected: PFMBA, 11Cl-PF3OUdS, 9Cl-PF3ONS, ADONA, HFPO-DA, PFBA, 6:2 FTS, 4:2 FTS, 8:2 FTS, PFPeA, PFHpS, PFUnA, PFBS, NFDHA, PFPeS, PFMPA, PFTA, PFEESA, PFTrDA, NEtFOSAA, NMeFOSAA, PFHpA, PFHxA, PFNA, PFDA, PFDoA.

Lithium, tested in the same program: highest 58 ppb, detected in 4 of 13 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

Two routes work for PFAS. For drinking and cooking water only, a reverse osmosis system certified to NSF/ANSI 58 with a PFOA/PFOS reduction claim is the cheapest proven option. To treat every tap and shower, a whole-house carbon system with enough contact time works, but check that the maker has PFAS test data, not just a marketing claim. See the best filters for PFAS and how PFAS removal works.

Other systems in California

All 707 tested systems in California

ZIP codes served

90220

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 Compton-city, Water Dept. water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID CA1910026. https://wellandtap.com/pfas/california/compton-city-water-dept/

About this data

Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID CA1910026). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.