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State overview

Radon in South Dakota

Of South Dakota's 66 counties and county equivalents, EPA places 48 in Zone 1, 18 in Zone 2. Zones are county-wide predictions; testing is the only way to know your home's level.

Radon in the news

South Dakota stories

Headlines link to the original publishers via Google News. Updated 2026-10-27.

All 66 counties

CountyEPA zone
Aurora CountyZone 1
Beadle CountyZone 1
Bennett CountyZone 2
Bon Homme CountyZone 1
Brookings CountyZone 1
Brown CountyZone 1
Brule CountyZone 1
Buffalo CountyZone 1
Butte CountyZone 2
Campbell CountyZone 1
Charles Mix CountyZone 1
Clark CountyZone 1
Clay CountyZone 1
Codington CountyZone 1
Corson CountyZone 1
Custer CountyZone 2
Davison CountyZone 1
Day CountyZone 1
Deuel CountyZone 1
Dewey CountyZone 2
Douglas CountyZone 1
Edmunds CountyZone 1
Fall River CountyZone 2
Faulk CountyZone 1
Grant CountyZone 1
Gregory CountyZone 2
Haakon CountyZone 2
Hamlin CountyZone 1
Hand CountyZone 1
Hanson CountyZone 1
Harding CountyZone 2
Hughes CountyZone 1
Hutchinson CountyZone 1
Hyde CountyZone 1
Jackson CountyZone 2
Jerauld CountyZone 1
Jones CountyZone 2
Kingsbury CountyZone 1
Lake CountyZone 1
Lawrence CountyZone 2
Lincoln CountyZone 1
Lyman CountyZone 1
Marshall CountyZone 1
McCook CountyZone 1
McPherson CountyZone 1
Meade CountyZone 2
Mellette CountyZone 2
Miner CountyZone 1
Minnehaha CountyZone 1
Moody CountyZone 1
Oglala Lakota CountyZone 2
Pennington CountyZone 2
Perkins CountyZone 1
Potter CountyZone 1
Roberts CountyZone 1
Sanborn CountyZone 1
Spink CountyZone 1
Stanley CountyZone 1
Sully CountyZone 1
Todd CountyZone 2
Tripp CountyZone 2
Turner CountyZone 1
Union CountyZone 1
Walworth CountyZone 1
Yankton CountyZone 1
Ziebach CountyZone 2

Source: EPA radon zones spreadsheet (EPA 402/A-16/001).