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Radon Levels in Leavenworth County, Kansas

EPA puts Leavenworth County in Zone 1, its highest radon zone, and 26.8% of its 515 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

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  • Share at 4+ pCi/L

    26.8%

    5.2 pts below KS

    Leavenworth
    26.8%
    Kansas
    32.0%

    515 tests, 2022

  • Median result

    1.9pCi/L

    Below action level

    Leavenworth
    1.9 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2022

  • Tests reported

    515

    8th of 38 by tests

    Leavenworth
    515
    Johnson
    5,240

    Reported to CDC before any fix, 2022

  • 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 Kansas

    28 of 38

    Middle half

    Leavenworth
    26.8%
    Mitchell
    57.4%

    By share, of 38 with 30+ tests

Read a result for Leavenworth County

Starts at Leavenworth County's median, 1.9 pCi/L

1.9pCi/L

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

EPA’s reading of 1.9 pCi/L

Below 2 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 below 2 pCi/L, the level at which EPA says a fix should be considered. Leavenworth County's median reported result, 2022.

Interpret this reading

The data

Leavenworth County, At a glance

Leavenworth County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Leavenworth 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 71% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Leavenworth County, 2022

Share of reported tests at or above 4 pCi/L, by year, Leavenworth County
Share of reported tests at or above 4 pCi/L, by year, Leavenworth County
YearShare of reported tests at or above 4 pCi/L
201630.7%
201732.9%
201825.2%
201927.5%
202024.5%
202127.1%
202226.8%

2022: 26.8%. Across these years the share ran from 24.5% to 32.9%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 515 tests reported to CDC for Leavenworth 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

Leavenworth County, Compared

Leavenworth County radon figures, compared

Calculated by Radon411

Leavenworth County's 515 reported tests in 2022 had a middle value of 1.9 pCi/L and a maximum of 23.2 pCi/L, and 26.8% reached 4 pCi/L. Kansas as a whole (96 Kansas counties, pooled) comes to 32.0%: 5.2 points higher than here.

Among its state's counties it ranks 28th 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, 259 tests (50.3%) came in under 2 pCi/L, against 45.8% statewide, and 118 tests (22.9%) fell between 2 and 4, against 22.1% statewide. The busiest year on file was 2021, with 2,091 tests reported; the quietest, 2016, had 296.

EPA's 1993 zone map puts Leavenworth County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 71% of the county's land high radon potential.

Next door, the shares run from 25.8% in Douglas County to 45.9% in Platte County, MO, with Douglas County below Leavenworth County. Over 7 years of annual figures the share fell 3.9 points, from 30.7% in 2016 to 26.8% in 2022; its peak was 32.9% in 2017.

CDC also counts 9 tests taken after mitigation in Leavenworth 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, Leavenworth County against Kansas2016 to 2022, years with 30 or more tests: Leavenworth County 30.7% to 26.8%, the state's pooled share 32.0% in 2022.
Leavenworth CountyKansas, pooled
Share of reported tests at or above 4 pCi/L by year, Leavenworth County against Kansas: data table
YearTestsLeavenworth County, at or above 4 pCi/LKansas, pooled
201629630.7%35.4%
201760232.9%37.3%
201865625.2%37.3%
201972427.5%33.7%
202063324.5%31.3%
20212,09127.1%31.8%
202251526.8%32.0%
Leavenworth County against Kansas, the United States and nearby counties, 2022
AreaTestsAt or above 4 pCi/LMedianDifference from Leavenworth County
Leavenworth County51526.8%1.9 pCi/LThis county
Kansas, pooled96 counties, pooled18,38532.0%Not pooled+5.2 points
United States, pooled853 counties, pooled333,14023.9%Not pooled−2.9 points
Mitchell Countyhighest in the state4757.4%6.2 pCi/L+30.6 points
Crawford Countylowest in the state345.9%0.8 pCi/L−20.9 points
Platte County, MOborders it8545.9%3.7 pCi/L+19.1 points
Atchison County, KSborders it6041.7%3.3 pCi/L+14.9 points
Johnson County, KSborders it5,24041.2%3.0 pCi/L+14.4 points
Jefferson County, KSborders it5339.6%2.4 pCi/L+12.8 points
Wyandotte County, KSborders it68729.7%2.1 pCi/L+2.9 points
Douglas County, KSborders it86825.8%1.8 pCi/L−1.0 points
Where Leavenworth County's reported results fell, 2022, beside Kansas and the United States
ResultLeavenworth County testsLeavenworth County shareKansas shareU.S. shareAgainst Kansas
Under 2 pCi/L25950.3%45.8%54.5%+4.5 points
2 to 4 pCi/L11822.9%22.1%21.7%+0.8 points
4 pCi/L and above13826.8%32.0%23.9%−5.2 points
Leavenworth 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
Ellis County23 of 3819129.8%2.6 pCi/L
Wyandotte County24 of 3868729.7%2.1 pCi/L
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
Leavenworth County radon tests by year, against Kansas' pooled share
YearTestsAt or above 4 pCi/LMedianHighestKansas, pooledChange from the row before
202251526.8%1.9 pCi/L23.2 pCi/L32.0%−0.3 points
20212,09127.1%1.9 pCi/L24.9 pCi/L31.8%+2.6 points
202063324.5%1.9 pCi/L26.7 pCi/L31.3%−3.0 points
201972427.5%2.0 pCi/L42.1 pCi/L33.7%+2.3 points
201865625.2%2.0 pCi/L20.3 pCi/L37.3%−7.7 points
201760232.9%2.4 pCi/L49.7 pCi/L37.3%+2.2 points
201629630.7%2.6 pCi/L19.9 pCi/L35.4%First on file

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

Leavenworth County, Geology

The ground under Leavenworth County

Predicted

USGS's geologic map splits Leavenworth County: 71.2% of its land is high radon potential and 28.8% moderate. The map puts 70.9% of Leavenworth County in the area it calls Glacial Drift and 28.8% in Glaciated Area. USGS gives the first a radon index of 12, in the high band (12 to 17), and the second 9, in the moderate band (9 to 11).

USGS's geologic areas under Leavenworth County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Glacial DriftGlacial drift and loess of varying thickness, largely locally derived from underlying and nearby Paleozoic sedimentary rocks.High1270.9%
Glaciated AreaGlacial till underlain by Pennsylvanian and Permian marine and nonmarine sedimentary shale, sandstone, limestone, coal.Moderate928.8%

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

Leavenworth County beside the ground around it

Leavenworth County has more high-potential ground than Kansas as a whole: 71.2% of its land against 59.9%. Of the 6 counties that border it, 4 have more high-potential ground, Platte County, MO the most at 100%.

Share of land by USGS radon potential: Leavenworth County, the 6 counties bordering it and Kansas
AreaEPA zoneLow potentialModerate potentialHigh potential
Leavenworth CountyZone 1None28.8%71.2%
Wyandotte CountyZone 1NoneNone100%
Platte County, MOZone 1NoneNone100%
Johnson CountyZone 1None2.4%97.6%
Jefferson CountyZone 2None70.7%29.3%
Douglas CountyZone 1None100%None
Atchison CountyZone 1None6.5%93.5%
Kansas105 counties, pooled by land areaVariesNone40.1%59.9%

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

Local help

Leavenworth County, Local resources

Radon testing and mitigation in Leavenworth County

Listed radon businesses with an address in Leavenworth County:

Listed radon professionals by town: Basehor, Bonner Springs

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

What it means

Leavenworth County, Questions

Questions about radon in Leavenworth County

Are radon levels high in Leavenworth County?

In 2022, 26.8% of the radon tests reported to CDC for Leavenworth County, Kansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.9 pCi/L. Of 38 Kansas counties with 30 or more tests for the same period, 27 reported a higher share; pooled, the state comes to 32.0%.

Which counties border Leavenworth County?

Leavenworth County borders 6 counties: Wyandotte County, KS, Platte County, MO, Johnson County, KS, Jefferson County, KS, Douglas County, KS and Atchison County, KS.

Products

Leavenworth County, Products

Testing a home in Leavenworth County

In Leavenworth County, 26.8% of 515 tests reported to CDC in 2022 reached 4 pCi/L, against 32.0% pooled across Kansas. In Zone 1 the year-round level in Leavenworth 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

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

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Leavenworth County, Bordering counties

Counties bordering Leavenworth County

Calculated by Radon411

Leavenworth County, Cities and towns

Cities and towns in Leavenworth County

The Census Bureau estimates 84,590 residents in Leavenworth County for July 1, 2025, 2,616 more than in 2020 (+3.2%). That works out to 183 people per square mile of land. Its largest town, Leavenworth, has 37,012 residents, 43.8% of the total. CDC's 515 reported tests for 2022 work out to 6.1 per 1,000 residents (2025 estimate), close to Kansas' 6.2.

From Leavenworth to Easton, CDC publishes no figure by town: each reads Leavenworth County's.

The cities and towns in Leavenworth County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Leavenworth37,012−0.8%43.8%
Lansing11,331+0.8%13.4%
Basehor8,249+18.7%9.8%
Bonner Springsextends beyond Leavenworth County7,962+1.8%Counted whole
De Sotoextends beyond Leavenworth County7,083+15.1%Counted whole
Tonganoxie6,208+11.0%7.3%
Linwood432+3.6%0.5%
Easton209−0.5%0.2%

8 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 Leavenworth County is counted whole, so it has no share.

Leavenworth County, Homes

Homes in Leavenworth County

Leavenworth County is a place of houses on their own lots: 77% of its 31,589 homes are detached single-family houses, against 72% across Kansas. Half of its homes were built before 1982, close to Kansas' 1975: 27% date from before 1960 and 27% from 2000 or later. 69% of occupied homes are lived in by their owner (Kansas: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Leavenworth County, Kansas, 2019 to 2023
HomesLeavenworth CountyKansas
Housing units31,5891,285,221
Detached houses77%72%
In buildings of 5 or more8%13%
Mobile homes2%4%
Built before 196027%33%
Built since 200027%20%
Middle year built19821975
Owner-occupied69%67%

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