Community Water System (CWS) · AZ0407100
Surface Water · serves an estimated 165,000 people · across Tempe
No numeric score yet
55.8 ng/L · sampled 2024
f-tempe-pfos
src-ucmr5-2024 · released 2026-01-15
The original published file, referenced from the source record.
Detected at up to 55.8 ng/L in 10 of 24 samples — about 14 times the 4.0 ng/L federal limit.
Why it matters. PFOS is linked in studies to immune, thyroid, liver, and developmental effects and to certain cancers. Like PFOA, it bioaccumulates, and the enforceable limit is set near the lowest measurable level.
What you can do. Relevant treatment: Reverse osmosis, Activated carbon (GAC), Anion exchange.
Understand Perfluorooctane sulfonic acid (PFOS) →| Substance | Result | Reference | Sampled | Status | Evidence |
|---|---|---|---|---|---|
| Perfluorooctane sulfonic acid (PFOS) | 55.8 ng/L | 4.0 ng/L federal MCL (2024) | 2024 | Above guideline | View evidence |
| Perfluorooctanoic acid (PFOA) | 38.7 ng/L | 4.0 ng/L federal MCL (2024) | 2024 | Above guideline | View evidence |
| Perfluorohexane sulfonic acid (PFHxS) | 70.5 ng/L | 10 ng/L federal MCL (2024) | 2024 | Above guideline | View evidence |
| Lead (90th percentile) | 4.4 µg/L | 15 µg/L federal action level | 2022-2024 | Below limit | View evidence |
A federal limit (an MCL or action level) is an enforceable legal cap. A health goal (an MCLG or health benchmark) is a non-enforceable target, often stricter, sometimes zero. A system meeting the legal limit is a compliance fact; it is not a guarantee of no health concern. PurityMap publishes no overall compliance verdict for a system; read each finding against its own reference below.
City of Tempe (PWS ID AZ0407100) is a public water system serving 165,000 people in Tempe, Arizona.
City of Tempe is on record as drawing from surface water. The source shapes which contaminants matter most for this system.
PurityMap's record for City of Tempe shows 3 findings measured above a benchmark and 1 within benchmark, from 4 evidence records. Every finding links to its source; a substance that was never monitored is shown as pending, not as a pass.
PurityMap does not issue a safety verdict. It publishes City of Tempe's measured results against each contaminant's benchmark so you can read them in context. Safety depends on the specific finding, your plumbing, and how the water reaches your tap.
The latest published record for City of Tempe is dated 2026-09-16. Utilities report on regulatory cycles, so results reflect the monitoring period rather than a live reading.