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Radon Levels in Chickasaw County, Iowa

EPA puts Chickasaw County in Zone 1, its highest radon zone, and high results are common there: 59.0% of the 498 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    59.0%

    0.5 pts above IA

    Chickasaw
    59.0%
    Iowa
    58.5%

    498 tests, 2008 to 2017

  • Median result

    4.9pCi/L

    Action level reached

    Chickasaw
    4.9 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    498

    48th of 99 by tests

    Chickasaw
    498
    Polk
    10,945

    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 Iowa

    69 of 99

    Middle half

    Chickasaw
    59.0%
    Sioux
    84.2%

    By share, of 99 with 30+ tests

Read a result for Chickasaw County

Starts at Chickasaw County's median, 4.9 pCi/L

4.9pCi/L

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

EPA’s reading of 4.9 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. Chickasaw County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Chickasaw County, At a glance

Chickasaw County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

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

Reported results by concentration band, Chickasaw County, 2008 to 2017, laboratory
Under 2 pCi/L: 19%2 to 4 pCi/L: 22%4 pCi/L and above: 59%

Of 498 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Chickasaw County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L9619.3%
2 to 4 pCi/L10821.7%
4 pCi/L and above29459.0%
What these figures count

These are the 498 tests reported to CDC for Chickasaw 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

Chickasaw County, Compared

Chickasaw County radon figures, compared

Calculated by Radon411

More than half: 59.0% of the 498 radon tests reported to CDC for Chickasaw County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 69th of 99 Iowa counties with 30 or more tests for the same period. That is 0.5 points above the 58.5% pooled from 99 Iowa counties.

The median result, 4.9 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 70.7 pCi/L. The rest split 19.3% under 2 pCi/L and 21.7% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 59.0% share point the same way here.

6 of its 7 bordering counties with figures ran higher, led by Mitchell County at 70.7%; Bremer County reported 53.0%. Statewide for the same period, Sioux County reported the highest share (84.2%) and Decatur County the lowest (25.9%).

CDC's ten-year totals for Chickasaw County went from 414 tests (2005 to 2014) to 498 (2008 to 2017), the share going from 62.6% to 59.0%.

Nationally, every county with a figure for the same period pools to 35.7%; Chickasaw County sits 23.3 points above it. CDC also counts 50 tests taken after mitigation in Chickasaw County for the same period: tests in homes where a fix was already in.

Chickasaw County against Iowa, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Chickasaw County
Chickasaw County49859.0%4.9 pCi/LThis county
Iowa, pooled99 counties, pooled95,24558.5%Not pooled−0.5 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−23.3 points
Sioux Countyhighest in the state1,98284.2%10.7 pCi/L+25.2 points
Decatur Countylowest in the state8525.9%2.5 pCi/L−33.1 points
Mitchell County, IAborders it44470.7%6.4 pCi/L+11.7 points
Winneshiek County, IAborders it1,07166.4%6.2 pCi/L+7.4 points
Fayette County, IAborders it74662.7%5.6 pCi/L+3.7 points
Howard County, IAborders it38861.3%5.9 pCi/L+2.3 points
Butler County, IAborders it37759.9%5.2 pCi/L+0.9 points
Floyd County, IAborders it69759.5%5.1 pCi/L+0.5 points
Bremer County, IAborders it95753.0%4.3 pCi/L−6.0 points
Where Chickasaw County's reported results fell, 2008 to 2017, laboratory, beside Iowa and the United States
ResultChickasaw County testsChickasaw County shareIowa shareU.S. shareAgainst Iowa
Under 2 pCi/L9619.3%21.8%39.6%−2.5 points
2 to 4 pCi/L10821.7%19.7%24.7%+2.0 points
4 pCi/L and above29459.0%58.5%35.7%+0.5 points
Chickasaw County ranked among the 99 Iowa counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Butler County64 of 9937759.9%5.2 pCi/L
Story County65 of 992,56859.9%5.0 pCi/L
Floyd County66 of 9969759.5%5.1 pCi/L
Jones County67 of 9955559.3%5.1 pCi/L
Iowa County68 of 9951959.2%5.1 pCi/L
Chickasaw County69 of 9949859.0%4.9 pCi/L
Cerro Gordo County70 of 991,66259.0%4.8 pCi/L
Dallas County71 of 992,35258.5%4.9 pCi/L
Pottawattamie County72 of 991,86857.4%4.7 pCi/L
Washington County73 of 991,18654.9%4.6 pCi/L
Bremer County74 of 9995753.0%4.3 pCi/L
Chickasaw County ten-year laboratory totals, against Iowa's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIowa, pooledChange from the row before
2008 to 201749859.0%4.9 pCi/L70.7 pCi/L58.5%−1.5 points
2007 to 201647360.5%5.1 pCi/L70.7 pCi/L58.6%+0.3 points
2006 to 201547260.2%5.0 pCi/L70.7 pCi/L59.4%−2.4 points
2005 to 201441462.6%5.3 pCi/L61.2 pCi/L59.6%First on file

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

Chickasaw County, Geology

The ground under Chickasaw County

Predicted

USGS's geologic map puts all of Chickasaw County's mapped land in one class: high radon potential. All of it lies in the area the map calls Iowan Surface, to which USGS gives a radon index of 12, in the high band (12 to 17).

USGS's geologic areas under Chickasaw County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Iowan SurfacePre-Illinoian glaical deposits and loess.High12100%

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

Chickasaw County beside the ground around it

On high-potential ground Chickasaw County is close to Iowa as a whole: 100% of its land against 98.8%. Of the 7 counties that border it, none has as large a share of high-potential ground; Bremer County comes nearest at 100%.

Share of land by USGS radon potential: Chickasaw County, the 7 counties bordering it and Iowa
AreaEPA zoneLow potentialModerate potentialHigh potential
Chickasaw CountyZone 1NoneNone100%
Bremer CountyZone 1NoneNone100%
Floyd CountyZone 1NoneNone100%
Howard CountyZone 1NoneNone100%
Butler CountyZone 1NoneNone100%
Fayette CountyZone 1NoneNone100%
Winneshiek CountyZone 1NoneNone100%
Mitchell CountyZone 1NoneNone100%
Iowa99 counties, pooled by land areaVariesNone1.2%98.8%

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

Local help

Chickasaw County, Local resources

Radon testing and mitigation in Chickasaw County

What Iowa's program says
Phone
(515) 281-4928
Licensing of radon professionals
Iowa’s radon program approves applications for persons who wish to become certified to perform radon testing or credentialed to perform mitigation and laboratories that provide radon testing devices and analytical services.
Disclosure when a home is sold or rented
However, per Iowa Code chapters 543B.9 and 543B.18 and Iowa Administrative Code 193E Chapter 14 administered by the Iowa Real Estate Commission, a seller must disclose any known tests for the presence of radon and if yes, provide the date of last report and the result(s).

What it means

Chickasaw County, Questions

Questions about radon in Chickasaw County

Are radon levels high in Chickasaw County?

Over the 2008 to 2017 laboratory totals, 59.0% of the radon tests reported to CDC for Chickasaw County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.9 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 68 reported a higher share; pooled, the state comes to 58.5%.

Which counties border Chickasaw County?

Chickasaw County borders 7 counties: Bremer County, Floyd County, Howard County, Butler County, Fayette County, Winneshiek County and Mitchell County.

Products

Chickasaw County, Products

Testing a home in Chickasaw County

In Chickasaw County, 59.0% of 498 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 58.5% pooled across Iowa. In Zone 1 the year-round level in Chickasaw 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

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

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Chickasaw County, Bordering counties

Counties bordering Chickasaw County

Calculated by Radon411

Chickasaw County, Cities and towns

Cities and towns in Chickasaw County

About 11,663 people live in Chickasaw County by the Census Bureau's estimate for July 1, 2025, 332 fewer than in 2020 (−2.8%). That works out to 23 people per square mile of land. Its largest town, New Hampton, has 3,420 residents, 29.3% of the total. CDC's 498 reported tests for 2008 to 2017 work out to 42.7 per 1,000 residents (2025 estimate), close to Iowa's 29.4.

From New Hampton to Bassett, CDC publishes no figure by town: each reads Chickasaw County's.

The cities and towns in Chickasaw County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
New Hampton3,420−2.0%29.3%
Nashuaextends beyond Chickasaw County1,505−3.0%Counted whole
Fredericksburg979−0.8%8.4%
Lawler391−3.5%3.4%
Protivinextends beyond Chickasaw County263−1.5%Counted whole
Ionia220−3.9%1.9%
Alta Vista216−4.8%1.9%
North Washington103−3.7%0.9%
Bassett43−2.3%0.4%

9 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 Chickasaw County is counted whole, so it has no share.

Chickasaw County, Homes

Homes in Chickasaw County

Chickasaw County is a place of houses on their own lots: 87% of its 5,545 homes are detached single-family houses, against 72% across Iowa. Half of its homes were built before 1965, close to Iowa's 1971: 46% date from before 1960 and 11% from 2000 or later. Owners live in 81% of the occupied homes (Iowa: 72%), so for most households a test and a fix are their own to order.

Homes in Chickasaw County, Iowa, 2019 to 2023
HomesChickasaw CountyIowa
Housing units5,5451,427,175
Detached houses87%72%
In buildings of 5 or more4%14%
Mobile homes3%3%
Built before 196046%39%
Built since 200011%21%
Middle year built19651971
Owner-occupied81%72%

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