Santa Clara County tap water
1 of 16 water systems serving Santa Clara County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 72 community water systems list this county as served; 15 serve 3,300+ people with full PFAS testing.
- 16 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 Jose Water | Surface water | 1,039,920 | No | 1 |
| City of Sunnyvale | Purchased surface water | 157,566 | No | 0 |
| City of Santa Clara | Purchased surface water | 134,587 | No | 0 |
| Great Oaks Wc Inc | Groundwater | 112,582 | No | 0 |
| City of San Jose - Evg/Edv/Coy | Purchased surface water | 99,783 | No | 0 |
| City of Milpitas | Purchased surface water | 81,915 | No | 0 |
| City of Mountain View | Purchased surface water | 81,340 | No | 0 |
| City of Palo Alto | Purchased surface water | 67,658 | No | 0 |
| Cwsc Los Altos Suburban | Purchased surface water | 63,559 | No | 0 |
| City of Gilroy | Groundwater | 59,426 | Yes | 1 |
| City of San Jose - Nsj/Alviso | Purchased surface water | 48,082 | No | 0 |
| City of Morgan Hill | Groundwater | 47,374 | 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.