Water report · not indexed
What is in the water at 95123
2 public water systems serve this ZIP code in the federal records. Everything below comes from EPA monitoring data, and everything missing is named.
SAN JOSE WATER
PWSID CA4310011 · CA · serves 1,039,920 people
PFAS and lithium
3 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 19 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| lithium | 10 µg/L | 5 | 8/22/2023 |
| PFOS | 0.0062 µg/L | 2 | 8/16/2023 |
| PFHxS | 0.0055 µg/L | 12 | 8/23/2023 |
A detection is a measurement, not a violation and not a health finding. EPA states that UCMR 5 results do not indicate compliance or non-compliance with any limit.
Health-based violations
No open health-based violation on record. This covers MCL, treatment technique and MRDL violations in SDWIS that have not been returned to compliance. It excludes monitoring and reporting violations, which are the large majority nationally, so this is not “no violations”, and SDWIS completeness varies by state.
Hardness
Median hardness 192 mg/L as CaCO₃, measured at 9 stations serving this system across 34 results, 2017-03-13 to 2022-04-05. Measured in the water source and distribution area, not at a tap, and not in your home.
GREAT OAKS WC INC
PWSID CA4310022 · CA · serves 110,088 people
PFAS and lithium
5 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 50 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| lithium | 16 µg/L | 34 | 6/25/2025 |
| PFHxS | 0.008 µg/L | 5 | 6/24/2025 |
| PFPeA | 0.0047 µg/L | 5 | 6/25/2025 |
| PFOS | 0.0046 µg/L | 1 | 12/17/2025 |
| PFHxA | 0.0045 µg/L | 5 | 6/25/2025 |
A detection is a measurement, not a violation and not a health finding. EPA states that UCMR 5 results do not indicate compliance or non-compliance with any limit.
Health-based violations
No open health-based violation on record. This covers MCL, treatment technique and MRDL violations in SDWIS that have not been returned to compliance. It excludes monitoring and reporting violations, which are the large majority nationally, so this is not “no violations”, and SDWIS completeness varies by state.
Hardness
Too few readings to state a hardness. 1 station(s), 6 result(s). Below two stations and five results this page will not state a number: a median of two readings from one creek is not your water.
What this report cannot tell you
Every figure describes water at a sampling point: a treatment plant, an entry point to the distribution system, or a monitoring station. None of it describes water arriving at your tap. Plumbing between the two can add lead and copper, and if your home was built before 1986 a test kit tells you something no federal dataset can.
Sources: EPA UCMR 5 occurrence (final release, frozen July 2026) · EPA SDWIS health-based violations · USGS and state monitoring via the Water Quality Portal · EPA Public Water System Service Area Boundaries v3. Compiled 2026-09-01.