Washington water quality
Washington has 4,750 active public water systems (10,046 on file total), 2,404 of them graded by TapGraded.
Grade distribution
Biggest water systems
SEATTLE PUBLIC UTILITIES
Seattle, WA · 1,161,961 served
TACOMA WATER DIVISION CITY OF
TACOMA, WA · 446,170 served
VANCOUVER CITY OF
Vancouver, WA · 373,047 served
SPOKANE CITY OF
Spokane, WA · 346,138 served
BELLEVUE CITY OF
Bellevue, WA · 321,349 served
ALDERWOOD WATER DISTRICT
Lynnwood, WA · 245,715 served
EVERETT PUBLIC WORKS DEPT. CITY OF
Everett, WA · 215,774 served
KENT WATER DEPARTMENT
Kent, WA · 166,421 served
REDMOND WATER SYSTEM CITY OF
Redmond, WA · 163,335 served
CLARK PUBLIC UTILITIES
VANCOUVER, WA · 153,526 served
Lowest-graded systems
Active, graded systems serving at least 10,000 people, ordered by lowest Tap Grade first.
FRUITLAND MUTUAL WATER COMPANY
PUYALLUP, WA · 15,313 served
MOSES LAKE CITY OF
Moses Lake, WA · 32,428 served
VERA WATER & POWER
Spokane Valley, WA · 24,692 served
SOUTHWOOD
Tacoma, WA · 64,155 served
CAMAS MUNICIPAL WATER SEWER SYSTEM
Camas, WA · 31,794 served
ALDERWOOD WATER DISTRICT
Lynnwood, WA · 245,715 served
NORTHSHORE UTILITY DISTRICT
Kenmore, WA · 99,789 served
KENNEWICK CITY OF
Kennewick, WA · 118,164 served
LACEY WATER DEPARTMENT
Lacey, WA · 105,178 served
PARKLAND LIGHT & WATER COMPANY
Tacoma, WA · 33,775 served
Cities in Washington
Source: EPA SDWIS/ECHO · Data as of 2026Q2