PlainWater
States → California

CWSC LOS ALTOS SUBURBAN

PWS ID: CA4310001 · SAN JOSE, California 95112

PFAS Detected

1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
69,973
Total Violations
7
Health-Based Violations
1
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Private
Connections
18,530
County
Santa Clara
School/Daycare
No
MCL Violations
1
Monitoring Violations
3
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Nitrate MR 2 1995
Coliform (TCR) MCL 1 1992
Simazine MR 1 2002

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 1080 samples detected PFAS.

Contaminant Date Result MRL Status
NMeFOSAA 8/14/2024 <0.006 µg/L 0.006 µg/L Not Detected
9Cl-PF3ONS 8/14/2024 <0.002 µg/L 0.002 µg/L Not Detected
ADONA 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 8/14/2024 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 8/14/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFDoA 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 8/14/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 8/14/2024 <0.004 µg/L 0.004 µg/L Not Detected
lithium 8/14/2024 <9 µg/L 9 µg/L Not Detected
NEtFOSAA 8/14/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 8/14/2024 <0.007 µg/L 0.007 µg/L Not Detected
PFTA 8/14/2024 <0.008 µg/L 0.008 µg/L Not Detected
PFNA 8/14/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFHpS 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 8/14/2024 <0.004 µg/L 0.004 µg/L Not Detected
HFPO-DA 8/14/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFHxA 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 8/14/2024 <0.004 µg/L 0.004 µg/L Not Detected
8:2 FTS 8/14/2024 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
6:2 FTS 8/14/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 8/14/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFBS 8/14/2024 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 8/14/2024 <0.02 µg/L 0.02 µg/L Not Detected
PFUnA 7/31/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFHxA 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOS 7/31/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
lithium 7/31/2023 <9 µg/L 9 µg/L Not Detected
NMeFOSAA 7/31/2023 <0.006 µg/L 0.006 µg/L Not Detected
11Cl-PF3OUdS 7/31/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 7/31/2023 <0.007 µg/L 0.007 µg/L Not Detected
PFPeA 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
NEtFOSAA 7/31/2023 <0.005 µg/L 0.005 µg/L Not Detected
9Cl-PF3ONS 7/31/2023 <0.002 µg/L 0.002 µg/L Not Detected
ADONA 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 7/31/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 7/31/2023 <0.005 µg/L 0.005 µg/L Not Detected
6:2 FTS 7/31/2023 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 7/31/2023 <0.003 µg/L 0.003 µg/L Not Detected
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.