Forensic evidence record · ev-ca3910005-f-manteca-pfos

Perfluorooctanesulfonic acid (PFOS)

A single published measurement record with its qualifier, sampling context, source identifier, method note, and stated limitations kept together.

Published evidence record

Non-Detect (ND)Reported measurement

Back to water-system profile

Non-Detect (ND)reported result

4 ng/Lreporting limit

Sample date: 2025-01-15 to 2025-10-21sample date

2026-10-15publication date

Source observations (24)

PFOS — Sample date: 2025-01-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0299-01 · Method EPA 533
PFOS — Sample date: 2025-04-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SID0373-01 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-01 · Method EPA 533
PFOS — Sample date: 2025-10-21
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIJ0557-01 · Method EPA 533
PFOS — Sample date: 2025-01-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0299-03 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-03 · Method EPA 533
PFOS — Sample date: 2025-01-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0299-05 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-05 · Method EPA 533
PFOS — Sample date: 2025-01-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0299-07 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-07 · Method EPA 533
PFOS — Sample date: 2025-01-23
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0487-01 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-09 · Method EPA 533
PFOS — Sample date: 2025-01-23
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0487-03 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-11 · Method EPA 533
PFOS — Sample date: 2025-01-23
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0487-05 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-13 · Method EPA 533
PFOS — Sample date: 2025-01-29
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0582-01 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-15 · Method EPA 533
PFOS — Sample date: 2025-01-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0299-09 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-17 · Method EPA 533
PFOS — Sample date: 2025-01-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0299-11 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-19 · Method EPA 533
PFOS — Sample date: 2025-01-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIA0299-13 · Method EPA 533
PFOS — Sample date: 2025-07-15
Below reporting limit. < Result value not available µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample SIG0372-21 · Method EPA 533

Measurement evidence

Analyte: Perfluorooctanesulfonic acid (PFOS)
Result qualifier: ND
Reference basis: 4.0 ng/L federal MCL (2024)
Sampling location: Entry Point to Distribution
Water system ID: CA3910005
Source ID: src-ucmr5-2024

Laboratory context

No laboratory method note was published with this record.

Sampling context

This result represents a entry point to distribution sample. It does not establish the condition at every distribution point or household tap.

Record limitation

System-level entry-point monitoring; not a measurement of the water at an individual household tap.

Source provenance

UCMR5 Analytical Results

Fifth Unregulated Contaminant Monitoring Rule (UCMR5) — PFAS occurrence data

U.S. Environmental Protection Agency · Published 2024

Nationwide entry-point monitoring for 29 PFAS and lithium under the fifth UCMR cycle. Results are entry-point-to-distribution samples, not household-tap measurements.

Open source profile →Original record

How to interpret this record

This page preserves one measurement. Interpretation requires its qualifier, reporting limit, reference basis, date, sampling location, and limitations; the number alone is not a safety verdict.

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