Washington drinking water quality
Washington has 4,692 active public water systems serving 10.2 million people. 1,856 of them, 40%, had at least one EPA violation in the past three years, 148 have an unresolved violation today, and 37 are designated serious violators by the EPA.
Active systems
4,692
in 39 counties
People served
10.2M
2,373 community systems serve 9.6M
Violations, past 3 years
1,856
40% of active systems
Serious violators
37
32 systems carry a health flag
Largest counties
All 39 countiesLargest community water systems
All 4,692 systems| System | Serves | Status |
|---|---|---|
| Seattle Public Utilities King County |
1,161,961 | |
| Tacoma Water Division City of Pierce County |
446,245 | |
| Vancouver City of Clark County |
373,047 | |
| Spokane City of Spokane County |
346,138 | |
| Bellevue City of King County |
321,349 | |
| Alderwood Water District Snohomish County |
245,715 | |
| Everett Public Works Dept. City of Snohomish County |
215,774 | |
| Kent Water Department King County |
166,421 | |
| Redmond Water System City of King County |
163,335 | |
| Clark Public Utilities Clark County |
153,526 |
About the Washington data
Retrieved from EPA ECHO on Oct 11, 2026. EPA records for Washington systems do not include town names, so searches here match on ZIP code, street address, or county.