Forensic evidence record · ev-ca0110008-f-pleasanton-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
26 ng/LReported measurementSource observations (8)
- PFOS — Sample date: 2024-08-20
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 AHH3474-03 · Method EPA 533
- PFOS — Sample date: 2024-11-21
Detected above reporting limit. = 0.008 µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample AHK3457-01 · Method EPA 533
- PFOS — Sample date: 2025-02-06
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 AIB1211-01 · Method EPA 533
- PFOS — Sample date: 2025-05-15
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 AIE2193-01 · Method EPA 533
- PFOS — Sample date: 2024-08-20
Detected above reporting limit. = 0.022 µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample AHH3474-02 · Method EPA 533
- PFOS — Sample date: 2025-02-05
Detected above reporting limit. = 0.026 µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample AIB1023-03 · Method EPA 533
- PFOS — Sample date: 2024-08-20
Detected above reporting limit. = 0.013 µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample AHH3474-01 · Method EPA 533
- PFOS — Sample date: 2025-02-05
Detected above reporting limit. = 0.015 µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample AIB1023-01 · Method EPA 533
Measurement evidence
- Analyte
- Perfluorooctanesulfonic acid (PFOS)
- Result qualifier
- =
- Reference basis
- 4.0 ng/L federal MCL (2024)
- Sampling location
- Entry Point to Distribution
- Water system ID
- CA0110008
- 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.
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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