Los Angeles County tap water
42 of 113 water systems serving Los Angeles County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 193 community water systems list this county as served; 109 serve 3,300+ people with full PFAS testing.
- 29 had a health-based violation since 2021-10-26.
Largest systems serving this county
| System | Source | People served (whole system) | PFAS above a 2024 level? | Violations since 2021-10-26 |
|---|---|---|---|---|
| Los Angeles-City, dept. of Water & Power | Surface water | 3,875,566 | No | 0 |
| Long Beach Utilities department | Purchased surface water | 466,772 | No | 0 |
| Santa Clarita Valley Water Agency | Surface water | 292,014 | Yes | 0 |
| Gswc - Southwest | Purchased surface water | 277,740 | No | 0 |
| San Gabriel Valley Water Co.-El Monte | Groundwater | 240,000 | No | 0 |
| Los Angeles Cwwd 40 Reg 4 & 34 Lancaster | Purchased surface water | 208,129 | No | 0 |
| Glendale-City, Water dept. | Purchased surface water | 192,212 | Yes | 0 |
| Suburban Water Systems-San Jose | Purchased surface water | 170,523 | No | 0 |
| Pasadena Water and Power | Purchased surface water | 165,448 | No | 0 |
| Pomona - City, Water dept. | Surface water | 151,713 | Yes | 0 |
| California Water Service CO. - Dominguez | Purchased surface water | 149,490 | No | 0 |
| California Water Service CO. - Ela | Purchased surface water | 142,140 | Yes | 0 |
Which one is yours? A county usually has several utilities. Your bill or your utility's annual water-quality report names yours. Population is for the whole system, which can cross county lines.
Not medical or legal advice. UCMR 5 results are screening data, not compliance determinations.
Sources and freshness
Public-water-system facts, violations and lead/copper results: EPA ECHO SDWA download (SDWIS snapshot 2026-10-13). PFAS and lithium results: EPA UCMR 5 final data (sampling 2023–2025). Both are U.S. government works, downloaded 2026-10-26. Numbers are computed by the published method; the same fields are in the open data files.