Forensic evidence record · ev-ca3610044-f-big-bear-lake-dwp-big-bear-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

6.1 ng/LReported measurement

Back to water-system profile

6.1 ng/Lreported result

Not verified from sourcereporting limit

Sample date: 2023-11-15 to 2024-04-24sample date

2026-10-15publication date

Source observations (40)

PFOS — Sample date: 2023-11-15
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 RGK0078-01 · Method EPA 533
PFOS — Sample date: 2023-11-15
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 RGK0078-03 · Method EPA 533
PFOS — Sample date: 2023-11-15
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 RGK0078-05 · Method EPA 533
PFOS — Sample date: 2024-04-17
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 RHD0109-01 · Method EPA 533
PFOS — Sample date: 2023-11-15
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 RGK0078-07 · Method EPA 533
PFOS — Sample date: 2024-04-17
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 RHD0109-03 · Method EPA 533
PFOS — Sample date: 2024-04-17
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 RHD0109-05 · Method EPA 533
PFOS — Sample date: 2023-11-16
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 RGK0098-01 · Method EPA 533
PFOS — Sample date: 2024-04-17
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 RHD0109-09 · Method EPA 533
PFOS — Sample date: 2023-11-16
Detected above reporting limit. = 0.0061 µg/L
Reporting limit: 0.004 µg/L. Detection limit: Not available. Benchmark unavailable
Source: src-ucmr5-2024 · UCMR5_All.txt · Sample RGK0098-03 · Method EPA 533
PFOS — Sample date: 2023-11-16
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 RGK0098-05 · Method EPA 533
PFOS — Sample date: 2024-04-17
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 RHD0109-07 · Method EPA 533
PFOS — Sample date: 2023-11-16
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 RGK0098-07 · Method EPA 533
PFOS — Sample date: 2024-04-17
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 RHD0109-11 · Method EPA 533
PFOS — Sample date: 2023-11-16
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 RGK0098-09 · Method EPA 533
PFOS — Sample date: 2024-04-17
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 RHD0109-13 · Method EPA 533
PFOS — Sample date: 2023-11-29
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 RGK0143-01 · Method EPA 533
PFOS — Sample date: 2024-04-18
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 RHD0113-01 · Method EPA 533
PFOS — Sample date: 2023-11-29
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 RGK0143-03 · Method EPA 533
PFOS — Sample date: 2024-04-18
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 RHD0113-03 · Method EPA 533
PFOS — Sample date: 2023-12-06
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 RGL0038-01 · Method EPA 533
PFOS — Sample date: 2024-04-24
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 RHD0152-01 · Method EPA 533
PFOS — Sample date: 2023-12-06
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 RGL0038-03 · Method EPA 533
PFOS — Sample date: 2024-04-24
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 RHD0152-03 · Method EPA 533
PFOS — Sample date: 2023-12-06
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 RGL0038-05 · Method EPA 533
PFOS — Sample date: 2024-04-18
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 RHD0113-05 · Method EPA 533
PFOS — Sample date: 2024-04-10
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 RHD0063-01 · Method EPA 533
PFOS — Sample date: 2024-04-18
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 RHD0113-07 · Method EPA 533
PFOS — Sample date: 2023-11-29
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 RGK0143-05 · Method EPA 533
PFOS — Sample date: 2024-04-18
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 RHD0113-09 · Method EPA 533
PFOS — Sample date: 2023-11-29
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 RGK0143-07 · Method EPA 533
PFOS — Sample date: 2024-04-18
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 RHD0113-11 · Method EPA 533
PFOS — Sample date: 2023-12-06
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 RGL0038-09 · Method EPA 533
PFOS — Sample date: 2024-04-24
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 RHD0154-03 · Method EPA 533
PFOS — Sample date: 2023-11-29
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 RGK0143-09 · Method EPA 533
PFOS — Sample date: 2024-04-24
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 RHD0154-05 · Method EPA 533
PFOS — Sample date: 2023-12-06
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 RGL0038-07 · Method EPA 533
PFOS — Sample date: 2024-04-24
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 RHD0154-01 · Method EPA 533
PFOS — Sample date: 2023-12-13
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 RGL0077-01 · Method EPA 533
PFOS — Sample date: 2024-04-24
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 RHD0154-07 · 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: CA3610044
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.

Review finding states →

Related intelligence

Water-system profile Data sources Methodology Evidence verification