CheckPFAS

GSWC - CLAREMONT

High Risk
PWSID: CA1910024 California Groundwater

2 PFAS compound(s) exceed EPA Maximum Contaminant Levels

This utility has until 2029 to install treatment under the EPA's April 2024 PFAS rule. In the meantime, a point-of-use filter certified NSF/ANSI 58 for PFOA/PFOS provides reliable interim protection.

7
PFAS Detected
2
Above EPA Limits
3
ZIPs Served
Groundwater
Water Source

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOA
Perfluorooctanoic acid
12.90ppt
323% of limit
4 ppt⚠ Exceeds MCL
PFOS
Perfluorooctane sulfonic acid
10.40ppt
260% of limit
4 ppt⚠ Exceeds MCL
PFHxS
Perfluorohexane sulfonic acid
3.70ppt
37% of limit
10 pptBelow limit
PFHxA
Perfluorohexanoic acid
8.40pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
6.40pptNo federal limitUnregulated
PFBS
Perfluorobutane sulfonic acid
5.10pptNo federal limitUnregulated
PFHpA
Perfluoroheptanoic acid
4.60pptNo federal limitUnregulated

ZIP Codes Served by This Utility

Click any ZIP to see the full result page for that area.

About this data
Source
EPA UCMR 5 — January 2026 release
Sampling period
January 2023 – December 2025
Water system ID (PWSID)
CA1910024
Detection threshold (MRL)
~1.5–2 ppt — "Not detected" means below this floor