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Radon Levels in Pottawatomie County, Kansas

EPA puts Pottawatomie County in Zone 1, its highest radon zone, and 25.2% of its 206 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

    25.2%

    6.8 pts below KS

    Pottawatomie
    25.2%
    Kansas
    32.0%

    206 tests, 2022

  • Median result

    1.7pCi/L

    Below action level

    Pottawatomie
    1.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2022

  • Tests reported

    206

    15th of 38 by tests

    Pottawatomie
    206
    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

    32 of 38

    Lowest quarter

    Pottawatomie
    25.2%
    Mitchell
    57.4%

    By share, of 38 with 30+ tests

Read a result for Pottawatomie County

Starts at Pottawatomie County's median, 1.7 pCi/L

1.7pCi/L

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

EPA’s reading of 1.7 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. Pottawatomie County's median reported result, 2022.

Interpret this reading

The data

Pottawatomie County, At a glance

Pottawatomie County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Pottawatomie 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 65% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Pottawatomie County, 2022

Share of reported tests at or above 4 pCi/L, by year, Pottawatomie County
Share of reported tests at or above 4 pCi/L, by year, Pottawatomie County
YearShare of reported tests at or above 4 pCi/L
201633.1%
201732.3%
201831.2%
201921.9%
202028.5%
202126.4%
202225.2%

2022: 25.2%. Across these years the share ran from 21.9% to 33.1%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 206 tests reported to CDC for Pottawatomie 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

Pottawatomie County, Compared

Pottawatomie County radon figures, compared

Calculated by Radon411

Pottawatomie County's 206 reported tests in 2022 had a middle value of 1.7 pCi/L and a maximum of 42.5 pCi/L, and 25.2% reached 4 pCi/L. Kansas as a whole (96 Kansas counties, pooled) comes to 32.0%: 6.8 points higher than here.

Among its state's counties it ranks 32nd 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, 113 tests (54.9%) came in under 2 pCi/L, against 45.8% statewide, and 41 tests (19.9%) fell between 2 and 4, against 22.1% statewide. The busiest year on file was 2021, with 921 tests reported; the quietest, 2016, had 151.

EPA's 1993 zone map puts Pottawatomie County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 65% of the county's land high radon potential.

Next door, the shares run from 29.0% in Wabaunsee County to 34.5% in Shawnee County. Over 7 years of annual figures the share fell 7.9 points, from 33.1% in 2016 to 25.2% in 2022; its peak was 33.1% in 2016.

CDC also counts 25 tests taken after mitigation in Pottawatomie 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, Pottawatomie County against Kansas2016 to 2022, years with 30 or more tests: Pottawatomie County 33.1% to 25.2%, the state's pooled share 32.0% in 2022.
Pottawatomie CountyKansas, pooled
Share of reported tests at or above 4 pCi/L by year, Pottawatomie County against Kansas: data table
YearTestsPottawatomie County, at or above 4 pCi/LKansas, pooled
201615133.1%35.4%
201729732.3%37.3%
201829231.2%37.3%
201927021.9%33.7%
202025628.5%31.3%
202192126.4%31.8%
202220625.2%32.0%
Pottawatomie County against Kansas, the United States and nearby counties, 2022
AreaTestsAt or above 4 pCi/LMedianDifference from Pottawatomie County
Pottawatomie County20625.2%1.7 pCi/LThis county
Kansas, pooled96 counties, pooled18,38532.0%Not pooled+6.8 points
United States, pooled853 counties, pooled333,14023.9%Not pooled−1.3 points
Mitchell Countyhighest in the state4757.4%6.2 pCi/L+32.2 points
Crawford Countylowest in the state345.9%0.8 pCi/L−19.3 points
Nemaha County, KSborders it2864.3%7.3 pCi/L+39.1 points
Shawnee County, KSborders it38834.5%2.6 pCi/L+9.3 points
Marshall County, KSborders it6631.8%1.9 pCi/L+6.6 points
Riley County, KSborders it80031.3%1.9 pCi/L+6.1 points
Wabaunsee County, KSborders it3129.0%2.2 pCi/L+3.8 points
Jackson County, KSborders it2123.8%2.7 pCi/L−1.4 points
Where Pottawatomie County's reported results fell, 2022, beside Kansas and the United States
ResultPottawatomie County testsPottawatomie County shareKansas shareU.S. shareAgainst Kansas
Under 2 pCi/L11354.9%45.8%54.5%+9.1 points
2 to 4 pCi/L4119.9%22.1%21.7%−2.2 points
4 pCi/L and above5225.2%32.0%23.9%−6.8 points
Pottawatomie 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
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
Montgomery County36 of 386911.6%0.8 pCi/L
Allen County37 of 38348.8%0.9 pCi/L
Pottawatomie County radon tests by year, against Kansas' pooled share
YearTestsAt or above 4 pCi/LMedianHighestKansas, pooledChange from the row before
202220625.2%1.7 pCi/L42.5 pCi/L32.0%−1.2 points
202192126.4%1.9 pCi/L24.3 pCi/L31.8%−2.1 points
202025628.5%2.2 pCi/L30.1 pCi/L31.3%+6.6 points
201927021.9%2.0 pCi/L34.9 pCi/L33.7%−9.3 points
201829231.2%2.3 pCi/L29.1 pCi/L37.3%−1.1 points
201729732.3%2.5 pCi/L40.8 pCi/L37.3%−0.8 points
201615133.1%2.9 pCi/L19.2 pCi/L35.4%First on file

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

Pottawatomie County, Geology

The ground under Pottawatomie County

Predicted

USGS's geologic map splits Pottawatomie County: 65.3% of its land is high radon potential and 34.7% moderate. The map puts 56.6% of Pottawatomie County in the area it calls Mid-Continent Rift Zone and 34.7% in Glaciated Area, with one smaller area beside them. 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 Pottawatomie County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Mid-Continent Rift ZoneFaulted and fractured Permian limestone, dolomite, shale, and sandstone related to the Mid-Continent Rift zone.High1256.6%
Glaciated AreaGlacial till underlain by Pennsylvanian and Permian marine and nonmarine sedimentary shale, sandstone, limestone, coal.Moderate934.7%
Glacial DriftGlacial drift and loess of varying thickness, largely locally derived from underlying and nearby Paleozoic sedimentary rocks.High128.6%

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

Pottawatomie County beside the ground around it

On high-potential ground Pottawatomie County is close to Kansas as a whole: 65.3% of its land against 59.9%. Of the 6 counties that border it, 3 have more high-potential ground, Riley County the most at 100%.

Share of land by USGS radon potential: Pottawatomie County, the 6 counties bordering it and Kansas
AreaEPA zoneLow potentialModerate potentialHigh potential
Pottawatomie CountyZone 1None34.7%65.3%
Riley CountyZone 1NoneNone100%
Wabaunsee CountyZone 2None62.4%37.6%
Marshall CountyZone 1None0.4%99.6%
Jackson CountyZone 1None52.6%47.4%
Nemaha CountyZone 1None16.6%83.4%
Shawnee CountyZone 2None79.3%20.7%
Kansas105 counties, pooled by land areaVariesNone40.1%59.9%

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

Local help

Pottawatomie County, Local resources

Radon testing and mitigation in Pottawatomie County

Listed radon businesses with an address in Pottawatomie County:

Listed radon professionals by town: Manhattan, Wamego, St. George

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

What it means

Pottawatomie County, Questions

Questions about radon in Pottawatomie County

Are radon levels high in Pottawatomie County?

In 2022, 25.2% of the radon tests reported to CDC for Pottawatomie County, Kansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.7 pCi/L. Of 38 Kansas counties with 30 or more tests for the same period, 31 reported a higher share; pooled, the state comes to 32.0%.

Which counties border Pottawatomie County?

Pottawatomie County borders 6 counties: Riley County, Wabaunsee County, Marshall County, Jackson County, Nemaha County and Shawnee County.

Products

Pottawatomie County, Products

Testing a home in Pottawatomie County

In Pottawatomie County, 25.2% of 206 tests reported to CDC in 2022 reached 4 pCi/L, against 32.0% pooled across Kansas. In Zone 1 the year-round level in Pottawatomie 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

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

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Pottawatomie County, Bordering counties

Counties bordering Pottawatomie County

Calculated by Radon411

Pottawatomie County, Cities and towns

Cities and towns in Pottawatomie County

Pottawatomie County is growing: the Census Bureau puts it at 27,186 residents on July 1, 2025, up 6.9% from 25,422 in 2020. That works out to 32 people per square mile of land. Manhattan, the largest place on its list (54,673 residents in all), extends beyond Pottawatomie County, so no share of the total is worked out for it. CDC's 206 reported tests for 2022 work out to 7.6 per 1,000 residents (2025 estimate), close to Kansas' 6.2.

From Manhattan to Wheaton, CDC publishes no figure by town: each reads Pottawatomie County's.

The cities and towns in Pottawatomie County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Manhattanextends beyond Pottawatomie County54,673+1.0%Counted whole
Wamegoextends beyond Pottawatomie County4,912+1.5%Counted whole
St. Marysextends beyond Pottawatomie County2,790+1.2%Counted whole
St. George1,165+10.0%4.3%
Westmoreland747+2.0%2.7%
Onaga683+0.1%2.5%
Olsburg225+1.8%0.8%
Belvue206+15.7%0.8%
Emmett170Level0.6%
Louisville151+12.7%0.6%
Havensville130+6.6%0.5%
Wheaton110+8.9%0.4%

12 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 Pottawatomie County is counted whole, so it has no share.

Pottawatomie County, Homes

Homes in Pottawatomie County

Pottawatomie County is a place of houses on their own lots: 79% of its 10,077 homes are detached single-family houses, against 72% across Kansas. Much of Pottawatomie County is recent building: 32% of its homes have gone up since 2000 and the middle year built is 1983, against 1975 for Kansas. Owners live in 82% of the occupied homes (Kansas: 67%), so for most households a test and a fix are their own to order.

Homes in Pottawatomie County, Kansas, 2019 to 2023
HomesPottawatomie CountyKansas
Housing units10,0771,285,221
Detached houses79%72%
In buildings of 5 or more3%13%
Mobile homes11%4%
Built before 196028%33%
Built since 200032%20%
Middle year built19831975
Owner-occupied82%67%

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