San Diego County tap water
2 of 23 water systems serving San Diego County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 80 community water systems list this county as served; 22 serve 3,300+ people with full PFAS testing.
- 22 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 |
|---|---|---|---|---|
| San Diego, City of | Surface water | 1,408,937 | No | 0 |
| Helix Water District | Surface water | 277,918 | No | 0 |
| Otay Water District | Purchased surface water | 242,155 | No | 0 |
| Sweetwater Authority | Surface water | 184,915 | Yes | 0 |
| Oceanside, City of | Purchased surface water | 174,340 | No | 0 |
| Vista Irrigation District | Surface water | 134,501 | No | 0 |
| Vallecitos Wd | Purchased surface water | 114,700 | No | 0 |
| Carlsbad Mwd | Purchased surface water | 96,371 | No | 0 |
| Padre Dam Mwd | Purchased surface water | 93,980 | No | 0 |
| Olivenhain Mwd | Purchased surface water | 86,458 | No | 0 |
| Poway, City of | Surface water | 49,888 | No | 0 |
| Camp Pendleton (South) | Groundwater | 44,555 | No | 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.