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Radon Levels in McKenzie County, North Dakota

EPA puts McKenzie County in Zone 1, its highest radon zone, and high results are common there: 56.1% of the 41 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

    56.1%

    3.2 pts below ND

    McKenzie
    56.1%
    ND
    59.3%

    41 tests, 2008 to 2017

  • Median result

    4.8pCi/L

    Action level reached

    McKenzie
    4.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    41

    22nd of 29 by tests

    McKenzie
    41
    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

    21 of 29

    Middle half

    McKenzie
    56.1%
    Pembina
    82.5%

    By share, of 29 with 30+ tests

Read a result for McKenzie County

Starts at McKenzie 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. McKenzie County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

McKenzie County, At a glance

McKenzie County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

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

Reported results by concentration band, McKenzie County, 2008 to 2017, laboratory
Under 2 pCi/L: 22%2 to 4 pCi/L: 22%4 pCi/L and above: 56%

Of 41 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, McKenzie County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L922.0%
2 to 4 pCi/L922.0%
4 pCi/L and above2356.1%
What these figures count

These are the 41 tests reported to CDC for McKenzie 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

McKenzie County, Compared

McKenzie County radon figures, compared

Calculated by Radon411

More than half: 56.1% of the 41 radon tests reported to CDC for McKenzie County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 21st of 29 North Dakota counties with 30 or more tests for the same period. That is 3.2 points below the 59.3% pooled from 53 North Dakota counties.

The median result, 4.8 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 16.1 pCi/L. The rest split 22.0% under 2 pCi/L and 22.0% 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 56.1% share point the same way here.

3 of its 4 bordering counties with figures ran higher, led by Richland County, MT at 78.6%; Williams County reported 33.8%. 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 McKenzie County went from 50 tests (2005 to 2014) to 41 (2008 to 2017), the share going from 62.0% to 56.1%.

Nationally, every county with a figure for the same period pools to 35.7%; McKenzie County sits 20.4 points above it.

McKenzie County against North Dakota, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from McKenzie County
McKenzie County4156.1%4.8 pCi/LThis county
North Dakota, pooled53 counties, pooled6,60759.3%Not pooled+3.2 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−20.4 points
Pembina Countyhighest in the state5782.5%9.3 pCi/L+26.4 points
Richland Countylowest in the state9343.0%3.6 pCi/L−13.1 points
Roosevelt County, MTborders it1693.8%8.7 pCi/L+37.7 points
Billings County, NDborders it2085.0%11.0 pCi/L+28.9 points
Richland County, MTborders it4278.6%5.9 pCi/L+22.5 points
Dunn County, NDborders it3574.3%7.1 pCi/L+18.2 points
Golden Valley County, NDborders it771.4%6.2 pCi/L+15.3 points
Mountrail County, NDborders it4866.7%7.3 pCi/L+10.6 points
Wibaux County, MTborders it450.0%3.0 pCi/L−6.1 points
Williams County, NDborders it20433.8%2.9 pCi/L−22.3 points
Where McKenzie County's reported results fell, 2008 to 2017, laboratory, beside North Dakota and the United States
ResultMcKenzie County testsMcKenzie County shareNorth Dakota shareU.S. shareAgainst North Dakota
Under 2 pCi/L922.0%18.3%39.6%+3.7 points
2 to 4 pCi/L922.0%22.4%24.7%−0.4 points
4 pCi/L and above2356.1%59.3%35.7%−3.2 points
McKenzie 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
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
Traill County23 of 293751.4%4.1 pCi/L
Burleigh County24 of 291,55851.1%4.0 pCi/L
Pierce County25 of 293948.7%3.8 pCi/L
Wells County26 of 298148.1%3.8 pCi/L
McKenzie 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 20174156.1%4.8 pCi/L16.1 pCi/L59.3%−3.5 points
2007 to 20164759.6%5.2 pCi/L17.2 pCi/L58.7%−5.6 points
2006 to 20154665.2%5.1 pCi/L17.2 pCi/L56.3%+3.2 points
2005 to 20145062.0%4.9 pCi/L17.2 pCi/L54.0%First on file

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

McKenzie County, Geology

The ground under McKenzie County

Predicted

USGS's geologic map puts all of McKenzie County's mapped land in one class: high radon potential. The map puts 73.3% of McKenzie County in the area it calls Great Plains (Glaciated) and 26.7% in Great Plains (Unglaciated). USGS gives both a radon index of 13, in the high band (12 to 17).

USGS's geologic areas under McKenzie County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Great Plains (Glaciated)Glacial deposits derived from Cretaceous shales containing higher than average amounts of uranium.High1373.3%
Great Plains (Unglaciated)Tertiary and Upper Cretaceous sandstones, shales, and locally, coal-bearing units.High1326.7%

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

McKenzie County beside the ground around it

On high-potential ground McKenzie County is close to North Dakota as a whole: 100% of its land against 98.9%. Of the 8 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: McKenzie County, the 8 counties bordering it and North Dakota
AreaEPA zoneLow potentialModerate potentialHigh potential
McKenzie CountyZone 1NoneNone100%
Williams CountyZone 1NoneNone100%
Dunn CountyZone 1NoneNone100%
Mountrail CountyZone 1NoneNone100%
Richland County, MTZone 1NoneNone100%
Billings CountyZone 1NoneNone100%
Wibaux County, MTZone 1None18.7%81.3%
Golden Valley CountyZone 1NoneNone100%
Roosevelt County, MTZone 1NoneNone100%
North Dakota53 counties, pooled by land areaVariesNone1.1%98.9%

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

Local help

McKenzie County, Local resources

Radon testing and mitigation in McKenzie County

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

What it means

McKenzie County, Questions

Questions about radon in McKenzie County

Are radon levels high in McKenzie County?

Over the 2008 to 2017 laboratory totals, 56.1% of the radon tests reported to CDC for McKenzie County, North Dakota were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.8 pCi/L. Of 29 North Dakota counties with 30 or more tests for the same period, 20 reported a higher share; pooled, the state comes to 59.3%.

Which counties border McKenzie County?

McKenzie County borders 8 counties: Williams County, ND, Dunn County, ND, Mountrail County, ND, Richland County, MT, Billings County, ND, Wibaux County, MT, Golden Valley County, ND and Roosevelt County, MT.

Products

McKenzie County, Products

Testing a home in McKenzie County

In McKenzie County, 56.1% of 41 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 McKenzie 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

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

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McKenzie County, Bordering counties

Counties bordering McKenzie County

Calculated by Radon411

McKenzie County, Cities and towns

Cities and towns in McKenzie County

The Census Bureau estimates 15,192 residents in McKenzie County for July 1, 2025, 414 more than in 2020 (+2.8%). Spread over its land, that is 5.5 people to the square mile. Its largest town, Watford City, has 6,378 residents, 42.0% of the total. Together its 3 incorporated places hold 46.1% of those residents; the other 53.9% live outside any of them. Reported testing is thin here: 41 tests over 2008 to 2017, or 2.7 for every 1,000 residents (2025 estimate), where North Dakota as a whole comes to 8.3.

From Watford City to Arnegard, CDC publishes no figure by town: each reads McKenzie County's.

The cities and towns in McKenzie County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Watford City6,378+2.0%42.0%
Alexander325+1.9%2.1%
Arnegard294+2.1%1.9%

3 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).

McKenzie County, Homes

Homes in McKenzie County

Fewer than six in ten of McKenzie County's 7,691 homes are detached houses (47%, against 57% across North Dakota); the rest are attached, in shared buildings or mobile. Much of McKenzie County is recent building: 64% of its homes have gone up since 2000 and the middle year built is 2010, against 1981 for North Dakota. 55% 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 McKenzie County, North Dakota, 2019 to 2023
HomesMcKenzie CountyNorth Dakota
Housing units7,691374,866
Detached houses47%57%
In buildings of 5 or more28%25%
Mobile homes18%7%
Built before 196012%24%
Built since 200064%31%
Middle year built20101981
Owner-occupied55%63%

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