Snohomish County tap water
0 of 19 water systems serving Snohomish County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 119 community water systems list this county as served; 18 serve 3,300+ people with full PFAS testing.
- 1 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 |
|---|---|---|---|---|
| Alderwood Water District | Purchased surface water | 245,715 | No | 0 |
| Everett Public Works dept. City of | Surface water | 215,774 | No | 0 |
| Marysville Utilities | Purchased surface water | 88,582 | No | 0 |
| Lynnwood City of | Purchased surface water | 68,204 | No | 0 |
| Sno Pud 1 - Lake Stevens | Purchased surface water | 67,710 | No | 0 |
| Silver Lake Water & Sewer District | Purchased surface water | 65,033 | No | 0 |
| Edmonds City of | Purchased surface water | 34,065 | No | 0 |
| Mukilteo Water & Wastewater Distr | Purchased surface water | 31,437 | No | 0 |
| Arlington City of | Purchased surface water | 29,508 | No | 0 |
| Mountlake Terrace City of | Purchased surface water | 26,402 | No | 0 |
| Cross Valley Water District | Purchased surface water | 24,695 | No | 0 |
| Monroe Water System | Purchased surface water | 23,467 | 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.