WaterCompared

Water report · not indexed

What is in the water at 91768

2 public water systems serve this ZIP code in the federal records. Everything below comes from EPA monitoring data, and everything missing is named.

CALIF STATE POLYTECHNICAL UNIV - POMONA

PWSID CA1910022 · CA

PFAS and lithium

4 compounds detected at or above the reporting limit under EPA’s UCMR 5 monitoring, across 4 samples.

CompoundHighest detectedSamplesMost recent
PFBS0.0063 µg/L16/16/2026
PFHxS0.0056 µg/L16/16/2026
PFHxA0.0039 µg/L16/16/2026
PFPeA0.0036 µg/L16/16/2026

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

1 open health-based violation(s) recorded in SDWIS and not yet returned to compliance.

  • TT · contaminant code 5200 · began 2024-10-17

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.

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.

CompoundHighest detectedSamplesMost recent
lithium9.3 µg/L18/23/2023
PFOS0.018 µg/L28/23/2023
PFHxS0.0079 µg/L28/23/2023
PFOA0.0071 µg/L28/23/2023
PFPeA0.0044 µg/L28/23/2023
PFHxA0.0041 µg/L28/23/2023
PFBS0.0032 µg/L28/23/2023

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.

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.