Water report · not indexed
What is in the water at 91710
4 public water systems serve this ZIP code in the federal records. Everything below comes from EPA monitoring data, and everything missing is named.
POMONA - CITY, WATER DEPT.
PWSID CA1910126 · CA · serves 151,713 people
PFAS and lithium
7 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 13 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| lithium | 9.3 µg/L | 1 | 8/23/2023 |
| PFOS | 0.018 µg/L | 2 | 8/23/2023 |
| PFHxS | 0.0079 µg/L | 2 | 8/23/2023 |
| PFOA | 0.0071 µg/L | 2 | 8/23/2023 |
| PFPeA | 0.0044 µg/L | 2 | 8/23/2023 |
| PFHxA | 0.0041 µg/L | 2 | 8/23/2023 |
| PFBS | 0.0032 µg/L | 2 | 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
Too few readings to state a hardness. 3 station(s), 4 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.
CHINO, CITY OF
PWSID CA3610012 · CA · serves 86,435 people
PFAS and lithium
Sampled, nothing detected. Tested for 30 compounds under UCMR 5 with none found at or above its reporting limit. A reporting limit is the lowest concentration the method can measure, so this means “below that” rather than “zero”.
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. 2 station(s), 3 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.
MONTE VISTA WD
PWSID CA3610029 · CA · serves 56,017 people
PFAS and lithium
5 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 16 samples.
| Compound | Highest detected | Samples | Most recent |
|---|---|---|---|
| PFBA | 0.011 µg/L | 2 | 9/9/2025 |
| PFHxS | 0.0074 µg/L | 7 | 9/9/2025 |
| PFOS | 0.0056 µg/L | 4 | 9/9/2025 |
| PFPeA | 0.0035 µg/L | 1 | 9/9/2025 |
| PFHxA | 0.0033 µg/L | 2 | 9/9/2025 |
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.
CALIFORNIA INSTITUTION FOR MEN
PWSID CA3610850 · CA · serves 10,667 people
PFAS and lithium
Sampled, nothing detected. Tested for 30 compounds under UCMR 5 with none found at or above its reporting limit. A reporting limit is the lowest concentration the method can measure, so this means “below that” rather than “zero”.
Health-based violations
4 open health-based violation(s) recorded in SDWIS and not yet returned to compliance.
- TT · contaminant code 0700 · began 2022-06-09
- TT · contaminant code 0700 · began 2022-06-09
- TT · contaminant code 0700 · began 2022-06-09
- TT · contaminant code 0700 · began 2022-06-09
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.
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.