Community Water System (CWS) · CA4110001
Surface Water · serves an estimated 30,609 people · across Mid-peninsula District
No numeric score yet
sampled 2024
f-mid-peninsula district-pfoa
src-ucmr5-2024 · released 2026-01-15
The original published file, referenced from the source record.
Not detected in the 2024 UCMR5 round.
Why it matters. Studies associate PFOA exposure with effects on the immune system, cholesterol, liver, and developmental outcomes, and with certain cancers. Because it accumulates, the EPA has set the enforceable limit near the lowest reliably measurable level.
Understand Perfluorooctanoic acid (PFOA) →| Substance | Result | Reference | Sampled | Status | Evidence |
|---|---|---|---|---|---|
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | 2024 | Not detected | View evidence |
| Perfluorooctane sulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | 2024 | Not detected | View evidence |
| Perfluorohexane sulfonic acid (PFHxS) | < 10 ng/L | 10.0 ng/L federal MCL (2024) | 2024 | Not detected | View evidence |
| Lead (90th percentile) | 0 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.
MID-PENINSULA WATER DISTRICT (PWS ID CA4110001) is a public water system serving 30,609 people in Mid-peninsula District, California.
MID-PENINSULA WATER DISTRICT is on record as drawing from surface water. The source shapes which contaminants matter most for this system.
PurityMap's record for MID-PENINSULA WATER DISTRICT shows 0 findings measured above a benchmark and 4 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 MID-PENINSULA WATER DISTRICT'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 MID-PENINSULA WATER DISTRICT is dated 2026-09-16. Utilities report on regulatory cycles, so results reflect the monitoring period rather than a live reading.