Radon zones in South Dakota
Last updated
EPA’s Map of Radon Zones places 66 South Dakota counties in its three radon potential zones: 48 in Zone 1 (highest), 18 in Zone 2 (moderate), and 0 in Zone 3 (low).
What this means for South Dakota homes
Most South Dakota counties fall in Zone 1. EPA predicts average indoor screening levels above 4 pCi/L across much of South Dakota, so elevated radon is common. Testing is especially worthwhile here, and radon-resistant construction features make sense for new homes.
EPA’s guidance is the same everywhere: test your home, fix it if the level is 4 pCi/L or higher, and consider fixing between 2 and 4 pCi/L. The zone map is from 1993 and should not be used to decide whether a single home needs testing.
South Dakota radon program
EPA lists the following state contact for South Dakota: SD Dept. of Environment & Natural Resources, phone 605-773-6038. Website: danr.sd.gov/Environment/AirQuality/Radon/default.aspx. State programs can tell you about local testing data, free or discounted test kits, disclosure rules for home sales, and credentialed radon professionals.
South Dakota counties and their EPA radon zones
| County | EPA radon zone |
|---|---|
| Aurora County | Zone 1 |
| Beadle County | Zone 1 |
| Bennett County | Zone 2 |
| Bon Homme County | Zone 1 |
| Brookings County | Zone 1 |
| Brown County | Zone 1 |
| Brule County | Zone 1 |
| Buffalo County | Zone 1 |
| Butte County | Zone 2 |
| Campbell County | Zone 1 |
| Charles Mix County | Zone 1 |
| Clark County | Zone 1 |
| Clay County | Zone 1 |
| Codington County | Zone 1 |
| Corson County | Zone 1 |
| Custer County | Zone 2 |
| Davison County | Zone 1 |
| Day County | Zone 1 |
| Deuel County | Zone 1 |
| Dewey County | Zone 2 |
| Douglas County | Zone 1 |
| Edmunds County | Zone 1 |
| Fall River County | Zone 2 |
| Faulk County | Zone 1 |
| Grant County | Zone 1 |
| Gregory County | Zone 2 |
| Haakon County | Zone 2 |
| Hamlin County | Zone 1 |
| Hand County | Zone 1 |
| Hanson County | Zone 1 |
| Harding County | Zone 2 |
| Hughes County | Zone 1 |
| Hutchinson County | Zone 1 |
| Hyde County | Zone 1 |
| Jackson County | Zone 2 |
| Jerauld County | Zone 1 |
| Jones County | Zone 2 |
| Kingsbury County | Zone 1 |
| Lake County | Zone 1 |
| Lawrence County | Zone 2 |
| Lincoln County | Zone 1 |
| Lyman County | Zone 1 |
| Marshall County | Zone 1 |
| McCook County | Zone 1 |
| McPherson County | Zone 1 |
| Meade County | Zone 2 |
| Mellette County | Zone 2 |
| Miner County | Zone 1 |
| Minnehaha County | Zone 1 |
| Moody County | Zone 1 |
| Oglala Lakota County (zone of Shannon County) | Zone 2 |
| Pennington County | Zone 2 |
| Perkins County | Zone 1 |
| Potter County | Zone 1 |
| Roberts County | Zone 1 |
| Sanborn County | Zone 1 |
| Spink County | Zone 1 |
| Stanley County | Zone 1 |
| Sully County | Zone 1 |
| Todd County | Zone 2 |
| Tripp County | Zone 2 |
| Turner County | Zone 1 |
| Union County | Zone 1 |
| Walworth County | Zone 1 |
| Yankton County | Zone 1 |
| Ziebach County | Zone 2 |
County names follow the 2020 Census. Zones from the EPA Map of Radon Zones (text version). Rows marked “zone of” use the zone EPA gave the predecessor or surrounding county.
Next steps: read how to test your home, check a result with the level calculator, or look up a single address by ZIP code.