Water report · not indexed
What is in the water at 91791
4 public water systems serve this ZIP code in the federal records. Everything below comes from EPA monitoring data, and everything missing is named.
AZUSA LIGHT AND WATER
PWSID CA1910007 · CA · serves 110,044 people
PFAS and lithium
3 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 6 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| PFOA | 0.0077 µg/L | 2 | 6/12/2024 |
| PFOS | 0.0058 µg/L | 3 | 6/12/2024 |
| PFHxA | 0.0035 µg/L | 1 | 12/14/2023 |
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
Too few readings to state a hardness. 1 station(s), 2 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.
COVINA-CITY, WATER DEPT.
PWSID CA1910127 · CA · serves 33,300 people
PFAS and lithium
1 compound detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 1 sample.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| lithium | 47 µg/L | 1 | 3/19/2025 |
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
No hardness measurement. Hardness is measured at environmental monitoring stations, and none fell inside this system’s service area. That is a gap in where monitoring happens, not a finding about the water.
VALENCIA HEIGHTS WATER CO.
PWSID CA1910163 · CA · serves 7,775 people
PFAS and lithium
7 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 18 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| lithium | 9.8 µg/L | 2 | 3/5/2024 |
| PFOA | 0.0057 µg/L | 4 | 6/4/2024 |
| PFOS | 0.0044 µg/L | 2 | 6/4/2024 |
| PFBS | 0.0044 µg/L | 4 | 6/4/2024 |
| PFHxA | 0.0043 µg/L | 2 | 12/2/2024 |
| PFPeA | 0.004 µg/L | 2 | 12/2/2024 |
| PFHxS | 0.0036 µg/L | 2 | 12/2/2024 |
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), 2 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.
SUBURBAN WATER SYSTEMS-SAN JOSE
PWSID CA1910205 · CA · serves 168,843 people
PFAS and lithium
5 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 12 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| lithium | 56 µg/L | 8 | 7/23/2024 |
| PFBA | 0.0062 µg/L | 1 | 7/23/2024 |
| PFBS | 0.0036 µg/L | 1 | 7/18/2024 |
| PFPeA | 0.0035 µg/L | 1 | 7/18/2024 |
| PFHxA | 0.0033 µg/L | 1 | 7/18/2024 |
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), 2 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.