PWSID
CA4310011
State
California
City
SAN JOSE
Population served
1,039,920
Primary source
Surface water
Score history
▼ 22 points — the score moved from 100 to 78 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 Aug 2023). Levels in parts per trillion (ppt).
PFOS
Perfluorooctanesulfonic acid
6.2 ppt
limit 4 ppt
PFHxS
Perfluorohexanesulfonic acid
3.2 ppt
limit 10 ppt
Lithium
9,110 ppt
limit —
Violations & enforcement
4
Violations on record
0
Unaddressed
3
Health-based
14
Enforcement actions
From EPA ECHO (SDWIS), most recent enforcement Aug 2023. Official EPA record →
Recent enforcement actions
- State action · SOX Aug 2023
- State action · SFL Jun 2023
- State action · SOX Jul 2020
- State action · SFL Apr 2020
- State action · SOX May 2017
- State action · SFL May 2017
- State action · SOX Jun 2000
- State action · SIA Jun 2000
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
8 stations · latest Jun 2023
Arsenic
2 stations · latest Apr 2022
Copper
1 station · latest Apr 2022
Fluoride
2 stations · latest Apr 2022
Uranium
2 stations · latest Apr 2022
Manganese
1 station · latest Apr 2022
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 CA4310011 — 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.