PFAS ("forever chemicals") · 2025
PFOS in Cary, NC tap water
Cary, NC's 2025 PFOS measurement is below the federal limit of 4 (MCL).
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Average Detection | Not detected | 4 MCL |
Range System-wide | 0–1.7 ng/L | 4 ng/L MCL |
Verbatim from Cary, NC'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 Cary, NC compares
5 of the 147 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 Cary, NC tap water?
Yes — Cary, NC's 2025 Consumer Confidence Report lists PFOS at Not detected. Cary, NC's 2025 PFOS measurement is below the federal limit of 4 (MCL).
+What's the federal limit for PFOS in drinking water?
The federal MCL for PFOS is 4 . 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 147 systems on The Water Map measuring PFOS report it at or above the federal limit. Examples include Charleston, SC, North Charleston, SC, City of Hialeah, FL.
+Where does this PFOS measurement come from?
This page reproduces the PFOS entry from the 2025 Consumer Confidence Report published by the Cary, NC 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/nc/cary/2025/source.