Forensic evidence record · ev-az0403008-f-flagstaff-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: 2023-03-28 to 2025-07-15sample date
2026-01-15publication date
Source observations (24)
  • PFOS — Sample date: 2024-06-20

    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 380-100876-1 · Method EPA 533

  • PFOS — Sample date: 2024-07-17

    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 380-104839-1 · Method EPA 533

  • PFOS — Sample date: 2025-06-16

    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 380-155880-1 · 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 380-161058-1 · 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 380-73077-1 · Method EPA 533

  • PFOS — Sample date: 2024-05-08

    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 380-95156-1 · Method EPA 533

  • PFOS — Sample date: 2024-05-28

    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 380-97664-1 · Method EPA 533

  • PFOS — Sample date: 2024-08-29

    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 380-111093-1 · Method EPA 533

  • PFOS — Sample date: 2023-03-28

    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 380-41928-1 · Method EPA 533

  • PFOS — Sample date: 2023-09-26

    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 380-64641-1 · Method EPA 533

  • PFOS — Sample date: 2024-04-25

    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 380-93218-1 · Method EPA 533

  • PFOS — Sample date: 2024-10-28

    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 380-119817-1 · Method EPA 533

  • PFOS — Sample date: 2024-03-20

    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 380-88205-1 · Method EPA 533

  • PFOS — Sample date: 2024-09-24

    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 380-114812-1 · Method EPA 533

  • PFOS — Sample date: 2024-03-20

    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 380-88205-2 · Method EPA 533

  • PFOS — Sample date: 2024-09-24

    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 380-114812-2 · Method EPA 533

  • PFOS — Sample date: 2023-04-26

    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 380-45197-1 · Method EPA 533

  • PFOS — Sample date: 2023-10-24

    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 380-68524-1 · Method EPA 533

  • PFOS — Sample date: 2024-04-25

    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 380-93218-2 · Method EPA 533

  • PFOS — Sample date: 2024-10-28

    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 380-119817-2 · Method EPA 533

  • PFOS — Sample date: 2023-03-28

    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 380-41928-2 · Method EPA 533

  • PFOS — Sample date: 2023-09-26

    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 380-64641-2 · Method EPA 533

  • PFOS — Sample date: 2023-06-15

    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 380-51417-1 · 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 380-73073-1 · 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
AZ0403008
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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