PlainWater
States

Washington Water Quality

4,557 public water systems serving 9,736,844 people.

Water Systems
4,557
Total Violations
314,648
Violation Rate
92.1%
PFAS Detection
39.7%
98 of 247 tested

Largest Water Systems

Most Violations

Counties in Washington

King
217 systems · 3,193,095 served · 20,636 violations
Pierce
359 systems · 1,138,508 served · 14,826 violations
Snohomish
170 systems · 947,238 served · 8,193 violations
Spokane
164 systems · 621,798 served · 9,829 violations
Clark
72 systems · 615,931 served · 9,864 violations
Thurston
322 systems · 395,780 served · 24,330 violations
Kitsap
221 systems · 331,366 served · 12,667 violations
Benton
113 systems · 281,453 served · 10,713 violations
Yakima
220 systems · 268,022 served · 12,104 violations
Whatcom
185 systems · 258,702 served · 11,873 violations
Skagit
87 systems · 156,499 served · 2,324 violations
Grant
268 systems · 145,560 served · 12,635 violations
Franklin
79 systems · 132,513 served · 3,941 violations
Chelan
132 systems · 118,807 served · 4,357 violations
Cowlitz
76 systems · 115,789 served · 13,735 violations
Island
308 systems · 104,049 served · 25,141 violations
Clallam
101 systems · 91,937 served · 6,174 violations
Lewis
166 systems · 88,839 served · 15,450 violations
Grays Harbor
88 systems · 83,246 served · 13,309 violations
Mason
241 systems · 78,167 served · 10,829 violations
Walla Walla
69 systems · 75,527 served · 8,476 violations
Whitman
33 systems · 65,902 served · 1,462 violations
Kittitas
104 systems · 51,670 served · 3,250 violations
Jefferson
70 systems · 46,719 served · 8,616 violations
Okanogan
123 systems · 44,103 served · 7,257 violations
Douglas
46 systems · 40,088 served · 3,795 violations
San Juan
112 systems · 39,901 served · 6,963 violations
Stevens
68 systems · 33,702 served · 10,726 violations
Pacific
38 systems · 33,692 served · 3,844 violations
Adams
48 systems · 25,650 served · 3,951 violations

Showing top 30 of 39 counties.