King County tap water
2 of 41 water systems serving King County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 156 community water systems list this county as served; 39 serve 3,300+ people with full PFAS testing.
- 7 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 |
|---|---|---|---|---|
| Seattle Public Utilities | Surface water | 1,161,961 | No | 0 |
| Bellevue City of | Purchased surface water | 321,349 | No | 0 |
| Kent Water department | Purchased surface water | 166,421 | No | 0 |
| Redmond Water System City of | Purchased surface water | 163,335 | No | 0 |
| Lakehaven Water and Sewer District | Purchased surface water | 148,809 | No | 0 |
| Renton City of | Groundwater | 108,091 | No | 0 |
| Auburn City of | Groundwater | 107,655 | No | 0 |
| Highline Water District | Purchased surface water | 100,170 | No | 0 |
| Northshore Utility District | Purchased surface water | 99,789 | No | 0 |
| Sammamish Plateau Water & Sewer | Purchased surface water | 79,362 | Yes | 0 |
| Soos Creek Water & Sewer District | Purchased surface water | 74,172 | No | 0 |
| Kirkland City of | Purchased surface water | 69,243 | 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.