EPA Zone Data 2026
WA Radon Levels
View EPA radon zone classifications for every county in WA. Select your county to see detailed risk data, testing recommendations, and mitigation cost estimates.
7
Zone 1
High Risk
High Risk
14
Zone 2
Moderate
Moderate
18
Zone 3
Low Risk
Low Risk
Adams
Zone 2
Asotin
Zone 2
Benton
Zone 2
Chelan
Zone 3
Clallam
Zone 3
Clark
Zone 1
Columbia
Zone 2
Cowlitz
Zone 3
Douglas
Zone 2
Ferry
Zone 1
Franklin
Zone 2
Garfield
Zone 2
Grant
Zone 2
Grays Harbor
Zone 3
Island
Zone 3
Jefferson
Zone 3
King
Zone 3
Kitsap
Zone 3
Kittitas
Zone 2
Klickitat
Zone 2
Lewis
Zone 3
Lincoln
Zone 2
Mason
Zone 3
Okanogan
Zone 1
Pacific
Zone 3
Pend Oreille
Zone 1
Pierce
Zone 3
San Juan
Zone 3
Skagit
Zone 3
Skamania
Zone 1
Snohomish
Zone 3
Spokane
Zone 1
Stevens
Zone 1
Thurston
Zone 3
Wahkiakum
Zone 3
Walla Walla
Zone 2
Whatcom
Zone 3
Whitman
Zone 2
Yakima
Zone 2
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