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Radon Levels in Turner County, South Dakota

EPA puts Turner County in Zone 1, its highest radon zone, and high results are common there: 58.6% of the 58 radon tests reported to CDC (2008 to 2017, laboratory totals) came back at or above 4 pCi/L. 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

    58.6%

    0.1 pts above SD

    Turner
    58.6%
    SD
    58.5%

    58 tests, 2008 to 2017

  • Median result

    4.8pCi/L

    Action level reached

    Turner
    4.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    58

    17th of 23 by tests

    Turner
    58
    Minnehaha
    1,920

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in SD

    13 of 23

    Middle half

    Turner
    58.6%
    Lake
    76.0%

    By share, of 23 with 30+ tests

Read a result for Turner County

Starts at Turner County's median, 4.8 pCi/L

4.8pCi/L

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

EPA’s reading of 4.8 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. Turner County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Turner County, At a glance

Turner County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Turner County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

USGS geologic potential: High across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Turner County, 2008 to 2017, laboratory

Reported results by concentration band, Turner County, 2008 to 2017, laboratory
Under 2 pCi/L: 19%2 to 4 pCi/L: 22%4 pCi/L and above: 59%

Of 58 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Turner County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L1119.0%
2 to 4 pCi/L1322.4%
4 pCi/L and above3458.6%
What these figures count

These are the 58 tests reported to CDC for Turner County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.

Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Turner County, Compared

Turner County radon figures, compared

Calculated by Radon411

More than half: 58.6% of the 58 radon tests reported to CDC for Turner County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 13th of 23 South Dakota counties with 30 or more tests for the same period. That is 0.1 points above the 58.5% pooled from 62 South Dakota counties.

The median result, 4.8 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 75.1 pCi/L. The rest split 19.0% under 2 pCi/L and 22.4% from 2 to 4 (South Dakota: 23.6% and 17.9%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 58.6% share point the same way here.

2 of its 6 bordering counties with figures ran higher, led by Yankton County at 72.9%; McCook County reported 50.0%. Statewide for the same period, Lake County reported the highest share (76.0%) and Davison County the lowest (48.8%).

CDC's ten-year totals for Turner County went from 29 tests (2005 to 2014) to 58 (2008 to 2017), the share going from 48.3% to 58.6%.

Nationally, every county with a figure for the same period pools to 35.7%; Turner County sits 22.9 points above it.

Turner County against South Dakota, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Turner County
Turner County5858.6%4.8 pCi/LThis county
South Dakota, pooled62 counties, pooled6,27558.5%Not pooled−0.1 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−22.9 points
Lake Countyhighest in the state5076.0%8.5 pCi/L+17.4 points
Davison Countylowest in the state8448.8%3.8 pCi/L−9.8 points
Yankton County, SDborders it11872.9%6.3 pCi/L+14.3 points
Hutchinson County, SDborders it3966.7%5.8 pCi/L+8.1 points
Minnehaha County, SDborders it1,92058.5%4.8 pCi/L−0.1 points
Lincoln County, SDborders it79556.5%4.7 pCi/L−2.1 points
Clay County, SDborders it8351.8%4.2 pCi/L−6.8 points
McCook County, SDborders it3050.0%3.9 pCi/L−8.6 points
Where Turner County's reported results fell, 2008 to 2017, laboratory, beside South Dakota and the United States
ResultTurner County testsTurner County shareSouth Dakota shareU.S. shareAgainst South Dakota
Under 2 pCi/L1119.0%23.6%39.6%−4.6 points
2 to 4 pCi/L1322.4%17.9%24.7%+4.5 points
4 pCi/L and above3458.6%58.5%35.7%+0.1 points
Turner County ranked among the 23 South Dakota counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Brule County8 of 233767.6%6.4 pCi/L
Hutchinson County9 of 233966.7%5.8 pCi/L
Custer County10 of 2310865.7%6.2 pCi/L
Codington County11 of 237764.9%5.8 pCi/L
Beadle County12 of 235459.3%4.8 pCi/L
Turner County13 of 235858.6%4.8 pCi/L
Minnehaha County14 of 231,92058.5%4.8 pCi/L
Lawrence County15 of 2316056.9%5.3 pCi/L
Lincoln County16 of 2379556.5%4.7 pCi/L
Grant County17 of 237855.1%5.0 pCi/L
Pennington County18 of 231,02953.6%4.3 pCi/L
Turner County ten-year laboratory totals, against South Dakota's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestSouth Dakota, pooledChange from the row before
2008 to 20175858.6%4.8 pCi/L75.1 pCi/L58.5%+6.4 points
2007 to 20164652.2%4.0 pCi/L75.1 pCi/L57.4%−1.1 points
2006 to 20154553.3%4.0 pCi/L75.1 pCi/L58.8%+5.0 points
2005 to 20142948.3%3.7 pCi/L75.1 pCi/L59.6%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Turner County, Geology

The ground under Turner County

Predicted

USGS's geologic map puts all of Turner County's mapped land in one class: high radon potential. All of it lies in the area the map calls Missouri Coteau/James River Lowland/Coteau des Prairies, to which USGS gives a radon index of 14, in the high band (12 to 17).

USGS's geologic areas under Turner County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Missouri Coteau/James River Lowland/Coteau des PrairiesGlacial drift derived largely from Cretaceous marine shale.High14100%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Turner County beside the ground around it

Turner County has more high-potential ground than South Dakota as a whole: 100% of its land against 56.7%. Of the 6 counties that border it, none has as large a share of high-potential ground; Clay County comes nearest at 100%.

Share of land by USGS radon potential: Turner County, the 6 counties bordering it and South Dakota
AreaEPA zoneLow potentialModerate potentialHigh potential
Turner CountyZone 1NoneNone100%
Lincoln CountyZone 1NoneNone100%
McCook CountyZone 1NoneNone100%
Yankton CountyZone 1NoneNone100%
Clay CountyZone 1NoneNone100%
Hutchinson CountyZone 1NoneNone100%
Minnehaha CountyZone 1NoneNone99.9%
South Dakota66 counties, pooled by land areaVaries1.0%42.3%56.7%

The map rates the ground, not the air in any home.

Local help

Turner County, Local resources

Radon testing and mitigation in Turner County

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

What it means

Turner County, Questions

Questions about radon in Turner County

Are radon levels high in Turner County?

Over the 2008 to 2017 laboratory totals, 58.6% of the radon tests reported to CDC for Turner County, South Dakota were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.8 pCi/L. Of 23 South Dakota counties with 30 or more tests for the same period, 12 reported a higher share; pooled, the state comes to 58.5%.

Which counties border Turner County?

Turner County borders 6 counties: Lincoln County, McCook County, Yankton County, Clay County, Hutchinson County and Minnehaha County.

Products

Turner County, Products

Testing a home in Turner County

In Turner County, 58.6% of 58 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 58.5% pooled across South Dakota. In Zone 1 the year-round level in Turner County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.

Test kits and monitors3

See every kit and monitor

Turner County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Turner County

Explore

Turner County, Bordering counties

Counties bordering Turner County

Calculated by Radon411

Turner County, Cities and towns

Cities and towns in Turner County

Turner County is growing: the Census Bureau puts it at 9,314 residents on July 1, 2025, up 7.3% from 8,684 in 2020. That works out to 15 people per square mile of land. No town dominates: Parker, the largest, has 1,349 residents, 14.5% of the total. CDC's 58 reported tests for 2008 to 2017 work out to 6.2 per 1,000 residents (2025 estimate), close to South Dakota's 6.7.

From Parker to Dolton, CDC publishes no figure by town: each reads Turner County's.

The cities and towns in Turner County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Parker1,349+12.4%14.5%
Centerville984+6.6%10.6%
Marion895+5.4%9.6%
Viborg853+5.0%9.2%
Ireneextends beyond Turner County439+2.6%Counted whole
Hurley391+3.7%4.2%
Chancellor322+7.0%3.5%
Monroe164+4.5%1.8%
Davis57+3.6%0.6%
Dolton39+11.4%0.4%

10 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Turner County is counted whole, so it has no share.

Turner County, Homes

Homes in Turner County

Turner County is a place of houses on their own lots: 86% of its 3,899 homes are detached single-family houses, against 67% across South Dakota. The homes are older than South Dakota's as a whole: half were built before 1963 (1979 for South Dakota), and 48% date from before 1960. Owners live in 79% of the occupied homes (South Dakota: 69%), so for most households a test and a fix are their own to order.

Homes in Turner County, South Dakota, 2019 to 2023
HomesTurner CountySouth Dakota
Housing units3,899402,364
Detached houses86%67%
In buildings of 5 or more5%16%
Mobile homes4%8%
Built before 196048%29%
Built since 200017%28%
Middle year built19631979
Owner-occupied79%69%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.