PFAS ("forever chemicals") · 2024
PFOS in Tempe, AZ tap water
Tempe, AZ's 2024 Consumer Confidence Report shows PFOS at or above the federal limit (4 ng/L MCL). Measured value is 2.3× the threshold.
The measurement
| Statistic | Value | Federal limit |
|---|---|---|
Range System-wide | 0–55 ng/L | None set |
Average System-wide | 9 ng/L | 4 ng/L MCL |
Average System-wide | 0.3 ng/L | 4 ng/L MCL |
Range System-wide | 0–30 ng/L | 4 ng/L MCL |
Verbatim from Tempe, AZ's 2024 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.
People also ask
+Is there PFOS in Tempe, AZ tap water?
Yes — Tempe, AZ's 2024 Consumer Confidence Report lists PFOS at 9 ng/L. Tempe, AZ's 2024 Consumer Confidence Report shows PFOS at or above the federal limit (4 ng/L MCL). Measured value is 2.3× 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.
+Where does this PFOS measurement come from?
This page reproduces the PFOS entry from the 2024 Consumer Confidence Report published by the Tempe, AZ 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/az/tempe/2024/source.