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South Dakota Radon Map and Levels by County

South Dakota's counties span EPA Zones 1 and 2. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    58.5%

    22.8 pts above U.S.

    South Dakota
    58.5%
    U.S.
    35.7%

    6,275 tests across 62 counties, 2008 to 2017

  • Rank among states

    3 of 47

    Ten highest states

    South Dakota
    58.5%
    North Dakota
    59.3%

    By share, every state pooled the same way, 2008 to 2017

  • Counties in EPA Zone 1

    48 of 66

    Most at highest potential

    Zone 1
    48
    Zone 2
    18

    Most counties sit in Zone 1; Zone 1 is the highest potential

  • Highest county

    76.0%

    Lake County

    Lake
    76.0%
    Davison
    48.8%

    Counties with 30+ tests, 2008 to 2017

Read a result for South Dakota

Starts at EPA's action level

4.0pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 4.0 pCi/L

At or above 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. 58.5% of South Dakota's reported tests reached 4 pCi/L, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

South Dakota, At a glance

South Dakota at a glance

Predicted: EPA radon zone

66 of 66 counties classified

EPA classifies counties, not states. Of the 66 counties in South Dakota with a zone, 48 are in Zone 1 and 18 in Zone 2.

  • Zone 1: Highest predicted potentialgreater than 4 pCi/L48 of 66 counties · 72.7%
  • Zone 2: Moderate predicted potential2 to 4 pCi/L18 of 66 counties · 27.3%

An EPA radon zone predicts a whole county. It is not intended to determine whether any individual home should be tested: homes with elevated levels occur in all three zones, and EPA recommends testing every home regardless of zone.

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

CDC test figures, county by county

CDC publishes South Dakota's radon test figures by county: 64 of its 66 counties have one. Each one's share is in the county list.

How to read these figures

South Dakota, Compared

South Dakota radon figures, compared

Calculated by Radon411
South Dakota, 2008 to 2017, laboratory
58.5%
of 6,275 tests at or above 4 pCi/L, pooled
Against the U.S.
+22.8points
35.7% pooled
Rank among the states
3 of 47
1 is the highest share
Counties with 30 or more tests
23
Highest
76.0%
Lake County
Lowest
48.8%
Davison County

Pooled across 62 counties, 58.5% of the 6,275 radon tests reported to CDC for South Dakota over the 2008 to 2017 laboratory totals were at or above 4 pCi/L: close to half or more. That is 3rd of 47 states with county figures for the period; Nebraska (58.5%) above it and Iowa (58.5%) below.

Its 23 counties with 30 or more tests run from 48.8% in Davison County to 76.0% in Lake County; in 22 of them half or more of the reported tests reached 4 pCi/L. By band, 22 counties at 50% or more, 1 county at 30% to 50%.

The national pool for the same period is 35.7%, so South Dakota runs 22.8 points above the country. EPA's 1993 map puts 48 of its 66 classified counties in Zone 1; the tests reported since bear that out at 58.5%.

Across its 4 overlapping ten-year totals, the share went from 59.6% (2005 to 2014) to 58.5% (2008 to 2017), within 2 points, with 2005 to 2014 the highest at 59.6%.

South Dakota ranked among 47 states by pooled share of tests at or above 4 pCi/L, 2008 to 2017, laboratory
StateRankCountiesTestsAt or above 4 pCi/L
North Dakota1 of 47536,60759.3%
Nebraska2 of 479342,78258.5%
South Dakota3 of 47626,27558.5%
Iowa4 of 479995,24558.5%
Ohio5 of 478898,84052.3%
Colorado6 of 476396,36747.0%
Wisconsin7 of 477268,10446.9%
Montana8 of 47519,89345.5%
Wyoming9 of 47237,63844.3%
Kentucky10 of 4712028,79343.7%
Minnesota11 of 4787130,91243.4%
South Dakota's highest and lowest counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/L
Lake County1 of 235076.0%
Bon Homme County2 of 236274.2%
Yankton County3 of 2311872.9%
Brown County4 of 236271.0%
Hughes County5 of 237170.4%
Brookings County6 of 2335668.5%
Kingsbury County7 of 234468.2%
Brule County8 of 233767.6%
Hutchinson County9 of 233966.7%
Custer County10 of 2310865.7%
Davison County23 of 238448.8%
McCook County22 of 233050.0%
Union County21 of 2334851.1%
Meade County20 of 2319751.8%
Clay County19 of 238351.8%
South Dakota's counties with 30 or more tests, by their own share at or above 4 pCi/L, 2008 to 2017, laboratory
ShareCountiesTheir testsFor example
50% or more225,776Lake County, Bon Homme County, Yankton County
30% to 50%184Davison County
15% to 30%00None
5% to 15%00None
Under 5%00None
South Dakota ten-year laboratory totals, pooled, against the United States
PeriodCountiesTestsAt or above 4 pCi/LUnited StatesChange from the row before
2008 to 2017626,27558.5%35.7%+1.1 points
2007 to 2016605,29957.4%35.8%−1.5 points
2006 to 2015634,89358.8%36.3%−0.8 points
2005 to 2014634,22459.6%36.0%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period. CDC publishes no state or national figure.

South Dakota, Counties

South Dakota counties by EPA zone

Predicted

South Dakota's radon map, then all 66 counties by EPA's zone, the highest reported share of tests at or above 4 pCi/L first; each has its own report.

South Dakota radon map by county: EPA radon zones. Map of South Dakota's 66 counties shaded by EPA radon zone: Zone 1 in red-orange, Zone 2 in amber. 48 in Zone 1, 18 in Zone 2, 0 in Zone 3.
South Dakota radon map by countyEPA radon zones for South Dakota's counties: 48 counties in Zone 1, 18 counties in Zone 2, 0 counties in Zone 3.A prediction for each county, not a reading of any home; elevated homes occur in all three zones.

The 12 highest in South Dakota, 2008 to 2017

Zone 1: highest predicted potential48

Local help

South Dakota, Local resources

Local resources in South Dakota

Who to ask in South Dakota: its radon program, test kits and professionals.

What South Dakota's program says
Phone
1-800-438-3367

What it means

South Dakota, Questions

Questions about radon in South Dakota

Is radon a problem in South Dakota?

EPA's Map of Radon Zones places 48 of the 66 South Dakota counties it classifies in Zone 1, the highest predicted potential, 18 in Zone 2 and 0 in Zone 3. Pooled from 62 counties, 58.5% of the 6,275 radon tests reported to CDC over the 2008 to 2017 laboratory totals were at or above 4 pCi/L, 3rd of 47 states.

Which South Dakota counties are in EPA radon Zone 1?

48 counties are in Zone 1: Aurora County, Beadle County, Bon Homme County, Brookings County, Brown County, Brule County, Buffalo County, Campbell County, and 40 more in the county table on this page.

Who does radon mitigation in South Dakota?

Radon411's South Dakota directory lists 5 radon businesses for testing, mitigation or both, each with the licensing list it was read from.

Which South Dakota counties have the highest radon?

By the share of reported tests at or above 4 pCi/L, 2008 to 2017, laboratory: Lake County 76.0% (50 tests), Bon Homme County 74.2% (62 tests), Yankton County 72.9% (118 tests), Brown County 71.0% (62 tests), Hughes County 70.4% (71 tests).

Which EPA region is South Dakota in?

South Dakota is in EPA Region 8: Mountains and Plains.

Products

South Dakota, Products

Testing a home in South Dakota

58.5% of the 6,275 tests reported to CDC for South Dakota over the 2008 to 2017 laboratory totals reached 4 pCi/L: a short-term kit (2 to 90 days) gives a first answer in days, a long-term test the year-round average. A short-term kit (2 to 90 days) is the quick first check for a home in South Dakota; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for South Dakota homes, compared

Explore

Cities in South Dakota with their own page

Radon data is published by county, not by city. Each city page sets the figures of the counties the city lies in side by side.