Snohomish County, Washington
Violation Analysis
Water Source Types
PFAS Contamination
PFAS (per- and polyfluoroalkyl substances) are persistent chemicals found in drinking water. The EPA has set enforceable limits for several PFAS compounds under UCMR5 monitoring.
Compliance Snapshot
Snohomish Washington water systems by violation status, EPA SDWIS records.
Violation history is cumulative — many flagged systems have already returned to compliance. Detail pages show per-system context.
Water Systems
Other Counties in Washington
Drinking Water Guides
Related Environmental Data
Frequently Asked Questions
How many water violations are in Snohomish County? ▼
How many people get water from Snohomish County systems? ▼
Has PFAS been detected in Snohomish County water? ▼
What types of water sources supply Snohomish County? ▼
Are health-based violations serious? ▼
Where does this water quality data come from? ▼
Data Sources & Methodology
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.
Violations are categorized as health-based (Maximum Contaminant Level exceedances, treatment technique failures) or monitoring/reporting violations. Not all violations indicate an immediate health risk.
Read our methodology — how this data is sourced, computed, and verified.