PlainWater
States → California

CWSC OAK HILLS

PWS ID: CA2710019 · SAN JOSE, California 95112

PFAS Detected

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

Population Served
3,161
Total Violations
9
Health-Based Violations
4
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
884
County
Monterey
School/Daycare
No
MCL Violations
4
Monitoring Violations
3
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
1,1-Dichloroethylene MCL 4 1996
TTHM MR 1 2005
Lead and Copper Rule MR 1 1993
Total Haloacetic Acids (HAA5) MR 1 2005

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 4 of 120 samples detected PFAS.

Contaminant Date Result MRL Status
NMeFOSAA 5/22/2023 <0.006 µg/L 0.006 µg/L Not Detected
PFDA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOS 5/22/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFNA 5/22/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpS 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 5/22/2023 <0.004 µg/L 0.004 µg/L Not Detected
lithium 5/22/2023 28.7000 µg/L 9 µg/L Detected
NEtFOSAA 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 5/22/2023 <0.007 µg/L 0.007 µg/L Not Detected
PFTA 5/22/2023 <0.008 µg/L 0.008 µg/L Not Detected
PFDoA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 5/22/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHxA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 5/22/2023 <0.02 µg/L 0.02 µg/L Not Detected
8:2 FTS 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFBA 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
HFPO-DA 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
ADONA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
9Cl-PF3ONS 5/22/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFUnA 5/22/2023 <0.002 µg/L 0.002 µg/L Not Detected
6:2 FTS 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
11Cl-PF3OUdS 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 5/22/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFTrDA 5/22/2023 <0.007 µg/L 0.007 µg/L Not Detected
11Cl-PF3OUdS 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
lithium 5/22/2023 28.2000 µg/L 9 µg/L Detected
PFBS 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFNA 5/22/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 5/22/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOA 5/22/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFDA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 5/22/2023 <0.002 µg/L 0.002 µg/L Not Detected
9Cl-PF3ONS 5/22/2023 <0.002 µg/L 0.002 µg/L Not Detected
ADONA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 5/22/2023 <0.005 µg/L 0.005 µg/L Not Detected
NMeFOSAA 5/22/2023 <0.006 µg/L 0.006 µg/L Not Detected
PFTA 5/22/2023 <0.008 µg/L 0.008 µg/L Not Detected
PFHxA 5/22/2023 <0.003 µg/L 0.003 µg/L Not Detected
NEtFOSAA 5/22/2023 <0.005 µg/L 0.005 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.