PFAS ("forever chemicals") · 2025
PFOS in City of Santa Ana, CA tap water
City of Santa Ana, CA's 2025 Consumer Confidence Report shows PFOS at or above the federal limit (4 ng/L MCL). Measured value is 3.6× the threshold.
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Highest single sample Entry point | 14.200000000000001 ng/L | 4 ng/L MCL |
Verbatim from City of Santa Ana, CA's 2025 Consumer Confidence Report — source document ↗
About PFOS
Perfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings.
Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
How City of Santa Ana, CA compares
5 of the 119 systems measuring PFOS on The Water Map have it at or above the federal limit:
Nearby systems also reporting PFOS:
People also ask
+Is there PFOS in City of Santa Ana, CA tap water?
Yes — City of Santa Ana, CA's 2025 Consumer Confidence Report lists PFOS at 14.200000000000001 ng/L. City of Santa Ana, CA's 2025 Consumer Confidence Report shows PFOS at or above the federal limit (4 ng/L MCL). Measured value is 3.6× the threshold.
+What's the federal limit for PFOS in drinking water?
The federal MCL for PFOS is 4 ng/L. The EPA enforces this against the regulated reporting statistic (running annual average or 90th percentile), not a single-sample spike.
+What is PFOS?
Perfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
+Which other U.S. cities have PFOS over the federal limit?
5 of the 119 systems on The Water Map measuring PFOS report it at or above the federal limit. Examples include City of Clovis, CA, City of North Miami Beach, FL, Chula Vista Sweetwater, CA.
+Where does this PFOS measurement come from?
This page reproduces the PFOS 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.