PWSID
CA4310022
State
California
City
SAN JOSE
Population served
110,088
Primary source
Groundwater
Score history
▼ 17 points — the score moved from 100 to 83 on Jun 18, 2026, as newly published EPA data was incorporated.
2 score updates logged since tracking began Jun 18, 2026. Each future EPA re-score adds a point.
PFAS & contaminant readings
Latest detections from EPA’s UCMR5 monitoring (through Dec 2025). Levels in parts per trillion (ppt).
PFOS
Perfluorooctanesulfonic acid
4.6 ppt
limit 4 ppt
PFHxS
Perfluorohexanesulfonic acid
8 ppt
limit 10 ppt
Lithium
15,400 ppt
limit —
PFPeA
4.7 ppt
limit —
PFHxA
4.5 ppt
limit —
Violations & enforcement
5
Violations on record
0
Unaddressed
3
Health-based
11
Enforcement actions
From EPA ECHO (SDWIS), most recent enforcement Apr 2015. Official EPA record →
Recent enforcement actions
- State action · SOX Apr 2015
- State action · SFL Apr 2015
- State action · SOX Oct 2013
- State action · SFL Oct 2013
- State action · SOX Nov 2005
- State action · SIA Oct 2005
- State action · SOX Sep 2005
- State action · SOX Aug 2004
Area water-quality monitoring
Environmental monitoring (rivers, wells, intakes) recorded in this system’s service area in the EPA/USGS Water Quality Portal since 2018 — source/ambient water, not finished tap water. Context for the watershed, not a reading from your tap.
Nitrate
1 station · latest May 2021
Source: Water Quality Portal (EPA/USGS/state agencies). Values are as-reported and aren’t health thresholds.
This profile is built from EPA public records for system CA4310022 — SDWIS violations and UCMR5 PFAS sampling. The score is system-level and can’t account for your home’s plumbing (older pipes can add lead at the tap). For health decisions, check your exact address, read the utility’s Consumer Confidence Report, and confirm with your provider.