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Radon Levels in Butler County, Kansas

EPA puts Butler County in Zone 2, its middle radon zone, and 25.5% of its 550 reported radon tests (2022) were 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    25.5%

    6.5 pts below KS

    Butler
    25.5%
    Kansas
    32.0%

    550 tests, 2022

  • Median result

    2.1pCi/L

    Below action level

    Butler
    2.1 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2022

  • Tests reported

    550

    7th of 38 by tests

    Butler
    550
    Johnson
    5,240

    Reported to CDC before any fix, 2022

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Kansas

    30 of 38

    Lowest quarter

    Butler
    25.5%
    Mitchell
    57.4%

    By share, of 38 with 30+ tests

Read a result for Butler County

Starts at Butler County's median, 2.1 pCi/L

2.1pCi/L

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

EPA’s reading of 2.1 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Butler County's median reported result, 2022.

Interpret this readingWhat a fix costs

The data

Butler County, At a glance

Butler County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Butler County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

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

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Butler County, 2022

Share of reported tests at or above 4 pCi/L, by year, Butler County
Share of reported tests at or above 4 pCi/L, by year, Butler County
YearShare of reported tests at or above 4 pCi/L
201628.6%
201731.3%
201833.8%
201927.8%
202031.1%
202126.4%
202225.5%

2022: 25.5%. Across these years the share ran from 25.5% to 33.8%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 550 tests reported to CDC for Butler County over 2022, 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: 2022. Measured data period: 2016 to 2022 (every CDC figure on file).

How to read these figures

Butler County, Compared

Butler County radon figures, compared

Calculated by Radon411

Butler County's 550 reported tests in 2022 had a middle value of 2.1 pCi/L and a maximum of 27.7 pCi/L, and 25.5% reached 4 pCi/L. Kansas as a whole (96 Kansas counties, pooled) comes to 32.0%: 6.5 points higher than here.

Among its state's counties it ranks 30th of 38 Kansas counties with 30 or more tests for the same period. Statewide for the same period, Mitchell County reported the highest share (57.4%) and Crawford County the lowest (5.9%).

Below the action level, 260 tests (47.3%) came in under 2 pCi/L, against 45.8% statewide, and 150 tests (27.3%) fell between 2 and 4, against 22.1% statewide. The busiest year on file was 2021, with 1,467 tests reported; the quietest, 2016, had 441.

EPA's 1993 zone map puts Butler County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

Next door, the shares run from 18.4% in Sedgwick County to 40.0% in Marion County, with Sedgwick County below Butler County. Over 7 years of annual figures the share fell 3.1 points, from 28.6% in 2016 to 25.5% in 2022; its peak was 33.8% in 2018.

CDC also counts 43 tests taken after mitigation in Butler County for the same period: tests in homes where a fix was already in.

Share of reported tests at or above 4 pCi/L by year, Butler County against Kansas2016 to 2022, years with 30 or more tests: Butler County 28.6% to 25.5%, the state's pooled share 32.0% in 2022.
Butler CountyKansas, pooled
Share of reported tests at or above 4 pCi/L by year, Butler County against Kansas: data table
YearTestsButler County, at or above 4 pCi/LKansas, pooled
201644128.6%35.4%
201745131.3%37.3%
201848233.8%37.3%
201951127.8%33.7%
202055731.1%31.3%
20211,46726.4%31.8%
202255025.5%32.0%
Butler County against Kansas, the United States and nearby counties, 2022
AreaTestsAt or above 4 pCi/LMedianDifference from Butler County
Butler County55025.5%2.1 pCi/LThis county
Kansas, pooled96 counties, pooled18,38532.0%Not pooled+6.5 points
United States, pooled853 counties, pooled333,14023.9%Not pooled−1.6 points
Mitchell Countyhighest in the state4757.4%6.2 pCi/L+31.9 points
Crawford Countylowest in the state345.9%0.8 pCi/L−19.6 points
Chase County, KSborders it366.7%4.4 pCi/L+41.2 points
Marion County, KSborders it4540.0%2.5 pCi/L+14.5 points
Cowley County, KSborders it11839.8%3.3 pCi/L+14.3 points
Harvey County, KSborders it23234.1%2.8 pCi/L+8.6 points
Sumner County, KSborders it7929.1%2.3 pCi/L+3.6 points
Sedgwick County, KSborders it4,91118.4%1.3 pCi/L−7.1 points
Greenwood County, KSborders it616.7%0.9 pCi/L−8.8 points
Where Butler County's reported results fell, 2022, beside Kansas and the United States
ResultButler County testsButler County shareKansas shareU.S. shareAgainst Kansas
Under 2 pCi/L26047.3%45.8%54.5%+1.5 points
2 to 4 pCi/L15027.3%22.1%21.7%+5.2 points
4 pCi/L and above14025.5%32.0%23.9%−6.5 points
Butler County ranked among the 38 Kansas counties with 30 or more tests, by share at or above 4 pCi/L, 2022
CountyRankTestsAt or above 4 pCi/LMedian
Sumner County25 of 387929.1%2.3 pCi/L
Wabaunsee County26 of 383129.0%2.2 pCi/L
Rice County27 of 385328.3%1.8 pCi/L
Leavenworth County28 of 3851526.8%1.9 pCi/L
Douglas County29 of 3886825.8%1.8 pCi/L
Butler County30 of 3855025.5%2.1 pCi/L
Reno County31 of 3824025.4%2.2 pCi/L
Pottawatomie County32 of 3820625.2%1.7 pCi/L
Geary County33 of 3836525.2%1.9 pCi/L
Finney County34 of 387623.7%3.0 pCi/L
Sedgwick County35 of 384,91118.4%1.3 pCi/L
Butler County radon tests by year, against Kansas' pooled share
YearTestsAt or above 4 pCi/LMedianHighestKansas, pooledChange from the row before
202255025.5%2.1 pCi/L27.7 pCi/L32.0%−0.9 points
20211,46726.4%2.0 pCi/L42.8 pCi/L31.8%−4.7 points
202055731.1%2.3 pCi/L38.5 pCi/L31.3%+3.3 points
201951127.8%2.3 pCi/L38.6 pCi/L33.7%−6.0 points
201848233.8%2.6 pCi/L23.4 pCi/L37.3%+2.5 points
201745131.3%2.5 pCi/L72.0 pCi/L37.3%+2.7 points
201644128.6%2.6 pCi/L42.2 pCi/L35.4%First on file

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

Butler County, Geology

The ground under Butler County

Predicted

USGS's geologic map puts all of Butler County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Glaciated Area, to which USGS gives a radon index of 9, in the moderate band (9 to 11).

USGS's geologic areas under Butler County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Glaciated AreaGlacial till underlain by Pennsylvanian and Permian marine and nonmarine sedimentary shale, sandstone, limestone, coal.Moderate9100%

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

Butler County beside the ground around it

Across Kansas 59.9% of the land is rated high; none of Butler County's is. Of the 8 counties that border it, 1 has more high-potential ground, Marion County the most at 17.7%.

Share of land by USGS radon potential: Butler County, the 8 counties bordering it and Kansas
AreaEPA zoneLow potentialModerate potentialHigh potential
Butler CountyZone 2None100%None
Greenwood CountyZone 2None100%None
Harvey CountyZone 2None100%None
Sedgwick CountyZone 2None100%None
Chase CountyZone 2None100%None
Marion CountyZone 1None82.3%17.7%
Elk CountyZone 2None100%None
Cowley CountyZone 20.2%99.8%None
Sumner CountyZone 20.3%99.7%None
Kansas105 counties, pooled by land areaVariesNone40.1%59.9%

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

Local help

Butler County, Local resources

Radon testing and mitigation in Butler County

Listed radon businesses with an address in Butler County:

Listed radon professionals by town: Augusta, Towanda

What Kansas's program says
Phone
(800) 693-5343

What it means

Butler County, Questions

Questions about radon in Butler County

Are radon levels high in Butler County?

In 2022, 25.5% of the radon tests reported to CDC for Butler County, Kansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.1 pCi/L. Of 38 Kansas counties with 30 or more tests for the same period, 29 reported a higher share; pooled, the state comes to 32.0%.

Which counties border Butler County?

Butler County borders 8 counties: Greenwood County, Harvey County, Sedgwick County, Chase County, Marion County, Elk County, Cowley County and Sumner County.

Products

Butler County, Products

Testing a home in Butler County

In Butler County, 25.5% of 550 tests reported to CDC in 2022 reached 4 pCi/L, against 32.0% pooled across Kansas. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Butler County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Butler County homes, compared

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Butler County, Bordering counties

Counties bordering Butler County

Calculated by Radon411

Butler County, Cities and towns

Cities and towns in Butler County

The Census Bureau estimates 69,484 residents in Butler County for July 1, 2025, 2,096 more than in 2020 (+3.1%). That works out to 49 people per square mile of land. Its largest town, Andover, has 17,370 residents, 25.0% of the total. Together its 13 incorporated places hold 71.2% of those residents; the other 28.8% live outside any of them. CDC's 550 reported tests for 2022 work out to 7.9 per 1,000 residents (2025 estimate), close to Kansas' 6.2.

From Andover to Latham, CDC publishes no figure by town: each reads Butler County's.

The 12 largest cities and towns in Butler County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Andover17,370+16.0%25.0%
El Dorado12,696−0.5%18.3%
Augusta9,073−1.8%13.1%
Rose Hill4,320+3.2%6.2%
Douglass1,506−2.7%2.2%
Towanda1,426−1.2%2.1%
Benton939−1.6%1.4%
Leon652−0.6%0.9%
Whitewater650−1.5%0.9%
Potwin411−2.8%0.6%
Elbing223−1.3%0.3%
Cassoday107−0.9%0.2%
  • Latham

13 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).

Butler County, Homes

Homes in Butler County

Butler County is a place of houses on their own lots: 80% of its 27,175 homes are detached single-family houses, against 72% across Kansas. Much of Butler County is recent building: 23% of its homes have gone up since 2000 and the middle year built is 1984, against 1975 for Kansas. Owners live in 78% of the occupied homes (Kansas: 67%), so for most households a test and a fix are their own to order.

Homes in Butler County, Kansas, 2019 to 2023
HomesButler CountyKansas
Housing units27,1751,285,221
Detached houses80%72%
In buildings of 5 or more4%13%
Mobile homes8%4%
Built before 196028%33%
Built since 200023%20%
Middle year built19841975
Owner-occupied78%67%

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