PFAS ("forever chemicals") · 2025

Perfluorohexanesulfonic acid in City of Santa Ana, CA tap water

Approaching the federal limit· 0.8× the limit

City of Santa Ana, CA's 2025 Perfluorohexanesulfonic acid level is between 80% and 100% of the federal limit (10 ng/L MCL) — measured but not in violation.

The measurement

StatisticValue
Highest single sample
Entry point
8.4 ng/L

Verbatim from City of Santa Ana, CA's 2025 Consumer Confidence Report — source document ↗

About Perfluorohexanesulfonic acid

Perfluorohexanesulfonic acid, a PFAS 'forever chemical.'

Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.

How City of Santa Ana, CA compares

5 of the 116 systems measuring Perfluorohexanesulfonic acid on The Water Map have it at or above the federal limit:

Nearby systems also reporting Perfluorohexanesulfonic acid:

People also ask

+Is there Perfluorohexanesulfonic acid in City of Santa Ana, CA tap water?

Yes — City of Santa Ana, CA's 2025 Consumer Confidence Report lists Perfluorohexanesulfonic acid at 8.4 ng/L. City of Santa Ana, CA's 2025 Perfluorohexanesulfonic acid level is between 80% and 100% of the federal limit (10 ng/L MCL) — measured but not in violation.

+What's the federal limit for Perfluorohexanesulfonic acid in drinking water?

The federal MCL for Perfluorohexanesulfonic acid is 10 ng/L. The EPA enforces this against the regulated reporting statistic (running annual average or 90th percentile), not a single-sample spike.

+What is Perfluorohexanesulfonic acid?

Perfluorohexanesulfonic acid, a PFAS 'forever chemical.' Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.

+Which other U.S. cities have Perfluorohexanesulfonic acid over the federal limit?

5 of the 116 systems on The Water Map measuring Perfluorohexanesulfonic acid report it at or above the federal limit. Examples include Burbank, CA, Chula Vista Sweetwater, CA, Chico, CA.

+Where does this Perfluorohexanesulfonic acid measurement come from?

This page reproduces the Perfluorohexanesulfonic acid entry from the 2025 Consumer Confidence Report published by the City of Santa Ana, CA water utility — the annual drinking-water report every U.S. utility is required by federal law to publish. The original source document is archived at /water/ca/santa-ana/2025/source.

Full report
All City of Santa Ana, CA water-quality data →
Every contaminant measured in the 2025 report.
Contaminant pillar
Perfluorohexanesulfonic acid across the U.S. →
Every public water system measuring Perfluorohexanesulfonic acid, ranked.