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Radon Levels in Stark County, North Dakota

EPA puts Stark County in Zone 1, its highest radon zone, and high results are common there: 62.4% of the 386 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

    62.4%

    3.1 pts above ND

    Stark
    62.4%
    ND
    59.3%

    386 tests, 2008 to 2017

  • Median result

    5.1pCi/L

    Action level reached

    Stark
    5.1 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    386

    5th of 29 by tests

    Stark
    386
    Burleigh
    1,558

    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 ND

    17 of 29

    Middle half

    Stark
    62.4%
    Pembina
    82.5%

    By share, of 29 with 30+ tests

Read a result for Stark County

Starts at Stark County's median, 5.1 pCi/L

5.1pCi/L

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

EPA’s reading of 5.1 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. Stark County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Stark County, At a glance

Stark County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Stark 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 Stark County, 2008 to 2017, laboratory

Reported results by concentration band, Stark County, 2008 to 2017, laboratory
Under 2 pCi/L: 16%2 to 4 pCi/L: 22%4 pCi/L and above: 62%

Of 386 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Stark County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L6115.8%
2 to 4 pCi/L8421.8%
4 pCi/L and above24162.4%
What these figures count

These are the 386 tests reported to CDC for Stark 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

Stark County, Compared

Stark County radon figures, compared

Calculated by Radon411

More than half: 62.4% of the 386 radon tests reported to CDC for Stark County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 17th of 29 North Dakota counties with 30 or more tests for the same period. That is 3.1 points above the 59.3% pooled from 53 North Dakota counties.

The median result, 5.1 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 62.6 pCi/L. The rest split 15.8% under 2 pCi/L and 21.8% from 2 to 4 (North Dakota: 18.3% and 22.4%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 62.4% share point the same way here.

2 of its 3 bordering counties with figures ran higher, led by Dunn County at 74.3%; Morton County reported 53.4%. Statewide for the same period, Pembina County reported the highest share (82.5%) and Williams County the lowest (33.8%).

CDC's ten-year totals for Stark County went from 405 tests (2005 to 2014) to 386 (2008 to 2017), the share going from 62.2% to 62.4%.

Nationally, every county with a figure for the same period pools to 35.7%; Stark County sits 26.7 points above it. CDC also counts 10 tests taken after mitigation in Stark County for the same period: tests in homes where a fix was already in.

Stark County against North Dakota, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Stark County
Stark County38662.4%5.1 pCi/LThis county
North Dakota, pooled53 counties, pooled6,60759.3%Not pooled−3.1 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−26.7 points
Pembina Countyhighest in the state5782.5%9.3 pCi/L+20.1 points
Williams Countylowest in the state20433.8%2.9 pCi/L−28.6 points
Billings County, NDborders it2085.0%11.0 pCi/L+22.6 points
Dunn County, NDborders it3574.3%7.1 pCi/L+11.9 points
Grant County, NDborders it2373.9%7.4 pCi/L+11.5 points
Slope County, NDborders it1070.0%10.3 pCi/L+7.6 points
Mercer County, NDborders it8563.5%5.7 pCi/L+1.1 points
Hettinger County, NDborders it1662.5%5.8 pCi/L+0.1 points
Morton County, NDborders it26853.4%4.2 pCi/L−9.0 points
Where Stark County's reported results fell, 2008 to 2017, laboratory, beside North Dakota and the United States
ResultStark County testsStark County shareNorth Dakota shareU.S. shareAgainst North Dakota
Under 2 pCi/L6115.8%18.3%39.6%−2.5 points
2 to 4 pCi/L8421.8%22.4%24.7%−0.6 points
4 pCi/L and above24162.4%59.3%35.7%+3.1 points
Stark County ranked among the 29 North 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
Dickey County12 of 297067.1%4.8 pCi/L
Mountrail County13 of 294866.7%7.3 pCi/L
Bottineau County14 of 2911164.0%5.7 pCi/L
Mercer County15 of 298563.5%5.7 pCi/L
McLean County16 of 299563.2%5.6 pCi/L
Stark County17 of 2938662.4%5.1 pCi/L
Ransom County18 of 2915161.6%5.8 pCi/L
Foster County19 of 293161.3%4.5 pCi/L
Cass County20 of 2986257.5%4.7 pCi/L
McKenzie County21 of 294156.1%4.8 pCi/L
Morton County22 of 2926853.4%4.2 pCi/L
Stark County ten-year laboratory totals, against North Dakota's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestNorth Dakota, pooledChange from the row before
2008 to 201738662.4%5.1 pCi/L62.6 pCi/L59.3%−0.4 points
2007 to 201639862.8%5.1 pCi/L62.6 pCi/L58.7%−0.7 points
2006 to 201538663.5%5.3 pCi/L62.6 pCi/L56.3%+1.3 points
2005 to 201440562.2%5.1 pCi/L62.6 pCi/L54.0%First on file

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

Stark County, Geology

The ground under Stark County

Predicted

USGS's geologic map puts all of Stark County's mapped land in one class: high radon potential. The map puts 93.3% of Stark County in the area it calls Great Plains (Unglaciated) and 6.7% in Great Plains (Glaciated). USGS gives both a radon index of 13, in the high band (12 to 17).

USGS's geologic areas under Stark County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Great Plains (Unglaciated)Tertiary and Upper Cretaceous sandstones, shales, and locally, coal-bearing units.High1393.3%
Great Plains (Glaciated)Glacial deposits derived from Cretaceous shales containing higher than average amounts of uranium.High136.7%

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

Stark County beside the ground around it

On high-potential ground Stark County is close to North Dakota as a whole: 100% of its land against 98.9%. Of the 7 counties that border it, none has as large a share of high-potential ground; Billings County comes nearest at 100%.

Share of land by USGS radon potential: Stark County, the 7 counties bordering it and North Dakota
AreaEPA zoneLow potentialModerate potentialHigh potential
Stark CountyZone 1NoneNone100%
Hettinger CountyZone 1NoneNone100%
Billings CountyZone 1NoneNone100%
Dunn CountyZone 1NoneNone100%
Slope CountyZone 1None9.5%90.5%
Mercer CountyZone 1NoneNone100%
Grant CountyZone 1None3.4%96.6%
Morton CountyZone 1NoneNone100%
North Dakota53 counties, pooled by land areaVariesNone1.1%98.9%

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

Local help

Stark County, Local resources

Radon testing and mitigation in Stark County

What North Dakota's program says
Phone
701-328-5166
Email
jOtto@nd.gov

What it means

Stark County, Questions

Questions about radon in Stark County

Are radon levels high in Stark County?

Over the 2008 to 2017 laboratory totals, 62.4% of the radon tests reported to CDC for Stark County, North Dakota were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.1 pCi/L. Of 29 North Dakota counties with 30 or more tests for the same period, 16 reported a higher share; pooled, the state comes to 59.3%.

Which counties border Stark County?

Stark County borders 7 counties: Hettinger County, Billings County, Dunn County, Slope County, Mercer County, Grant County and Morton County.

Products

Stark County, Products

Testing a home in Stark County

In Stark County, 62.4% of 386 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 59.3% pooled across North Dakota. In Zone 1 the year-round level in Stark 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

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

Explore

Stark County, Bordering counties

Counties bordering Stark County

Calculated by Radon411

Stark County, Cities and towns

Cities and towns in Stark County

The Census Bureau estimates 34,013 residents in Stark County for July 1, 2025, 182 more than in 2020 (+0.5%). That works out to 25 people per square mile of land. Dickinson alone is home to 25,870 of them, 76.1% of the total. Together its 6 incorporated places hold 83.8% of those residents; the other 16.2% live outside any of them. CDC's 386 reported tests for 2008 to 2017 work out to 11.3 per 1,000 residents (2025 estimate), close to North Dakota's 8.3.

From Dickinson to Taylor, CDC publishes no figure by town: each reads Stark County's.

The cities and towns in Stark County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Dickinson25,870+0.2%76.1%
Belfield999−0.1%2.9%
Richardton695+0.1%2.0%
South Heart419+6.1%1.2%
Gladstone283+7.2%0.8%
Taylor230−1.3%0.7%

6 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).

Stark County, Homes

Homes in Stark County

Of Stark County's 15,455 homes, 58% are detached houses, against 57% across North Dakota; 24% are in buildings of five or more homes. Half of its homes were built before 1987, close to North Dakota's 1981: 19% date from before 1960 and 40% from 2000 or later. 65% of occupied homes are lived in by their owner (North Dakota: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Stark County, North Dakota, 2019 to 2023
HomesStark CountyNorth Dakota
Housing units15,455374,866
Detached houses58%57%
In buildings of 5 or more24%25%
Mobile homes8%7%
Built before 196019%24%
Built since 200040%31%
Middle year built19871981
Owner-occupied65%63%

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