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Radon Levels in Clermont County, Ohio

EPA puts Clermont County in Zone 2, its middle radon zone, and high results are common there: 50.0% of the 1,363 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

    50.0%

    2.3 pts below OH

    Clermont
    50.0%
    Ohio
    52.3%

    1,363 tests, 2008 to 2017

  • Median result

    4.0pCi/L

    Action level reached

    Clermont
    4.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    1,363

    22nd of 79 by tests

    Clermont
    1,363
    Franklin
    16,142

    Reported to CDC before any fix, 2008 to 2017

  • 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 Ohio

    47 of 79

    Middle half

    Clermont
    50.0%
    Pickaway
    81.4%

    By share, of 79 with 30+ tests

Read a result for Clermont County

Starts at Clermont County's median, 4.0 pCi/L

4.0pCi/L

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

EPA’s reading of 4.0 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. Clermont County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Clermont County, At a glance

Clermont County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Clermont 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 Clermont County, 2008 to 2017, laboratory

Reported results by concentration band, Clermont County, 2008 to 2017, laboratory
Under 2 pCi/L: 24%2 to 4 pCi/L: 26%4 pCi/L and above: 50%

Of 1,363 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Clermont County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L32123.6%
2 to 4 pCi/L36026.4%
4 pCi/L and above68250.0%
What these figures count

These are the 1,363 tests reported to CDC for Clermont 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

Clermont County, Compared

Clermont County radon figures, compared

Calculated by Radon411

More than half: 50.0% of the 1,363 radon tests reported to CDC for Clermont County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 47th of 79 Ohio counties with 30 or more tests for the same period. That is 2.3 points below the 52.3% pooled from 88 Ohio counties.

The median result, 4.0 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 38.2 pCi/L. The rest split 23.6% under 2 pCi/L and 26.4% from 2 to 4 (Ohio: 23.1% and 24.6%). The reported tests do not follow EPA's Zone 2 label for Clermont County (predicted average between 2 and 4 pCi/L): 50.0% of them reached 4 pCi/L, fewer than that label suggests.

2 of its 6 bordering counties with figures ran higher, led by Warren County at 52.5%; Campbell County, KY reported 26.2%. Statewide for the same period, Pickaway County reported the highest share (81.4%) and Cuyahoga County the lowest (21.7%).

CDC's ten-year totals for Clermont County went from 1,246 tests (2005 to 2014) to 1,363 (2008 to 2017), the share going from 46.5% to 50.0%.

Nationally, every county with a figure for the same period pools to 35.7%; Clermont County sits 14.3 points above it. CDC also counts 45 tests taken after mitigation in Clermont County for the same period: tests in homes where a fix was already in.

Clermont County against Ohio, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Clermont County
Clermont County1,36350.0%4.0 pCi/LThis county
Ohio, pooled88 counties, pooled98,84052.3%Not pooled+2.3 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−14.3 points
Pickaway Countyhighest in the state18381.4%9.5 pCi/L+31.4 points
Cuyahoga Countylowest in the state10,09221.7%2.0 pCi/L−28.3 points
Warren County, OHborders it2,51252.5%4.2 pCi/L+2.5 points
Clinton County, OHborders it10352.4%4.2 pCi/L+2.4 points
Brown County, OHborders it7047.1%3.3 pCi/L−2.9 points
Hamilton County, OHborders it3,75434.7%2.8 pCi/L−15.3 points
Pendleton County, KYborders it3426.5%1.9 pCi/L−23.5 points
Campbell County, KYborders it54326.2%2.3 pCi/L−23.8 points
Bracken County, KYborders it520.0%2.0 pCi/L−30.0 points
Where Clermont County's reported results fell, 2008 to 2017, laboratory, beside Ohio and the United States
ResultClermont County testsClermont County shareOhio shareU.S. shareAgainst Ohio
Under 2 pCi/L32123.6%23.1%39.6%+0.5 points
2 to 4 pCi/L36026.4%24.6%24.7%+1.8 points
4 pCi/L and above68250.0%52.3%35.7%−2.3 points
Clermont County ranked among the 79 Ohio 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 County42 of 791,95354.3%4.4 pCi/L
Hocking County43 of 796053.3%4.0 pCi/L
Warren County44 of 792,51252.5%4.2 pCi/L
Clinton County45 of 7910352.4%4.2 pCi/L
Montgomery County46 of 792,92250.3%4.0 pCi/L
Clermont County47 of 791,36350.0%4.0 pCi/L
Harrison County48 of 794450.0%4.1 pCi/L
Jefferson County49 of 7927149.8%3.9 pCi/L
Columbiana County50 of 7966249.1%3.8 pCi/L
Perry County51 of 799048.9%3.8 pCi/L
Defiance County52 of 797048.6%3.8 pCi/L
Clermont County ten-year laboratory totals, against Ohio's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestOhio, pooledChange from the row before
2008 to 20171,36350.0%4.0 pCi/L38.2 pCi/L52.3%+0.7 points
2007 to 20161,37649.3%3.9 pCi/L38.2 pCi/L52.8%+1.0 points
2006 to 20151,36448.3%3.8 pCi/L38.2 pCi/L52.9%+1.8 points
2005 to 20141,24646.5%3.6 pCi/L38.2 pCi/L52.4%First on file

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

Clermont County, Geology

The ground under Clermont County

Predicted

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

USGS's geologic areas under Clermont County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Till PlainsOrdovician shale and limestone; glacial till.Moderate1199.9%

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

Clermont County beside the ground around it

Across Ohio 62.8% of the land is rated high; none of Clermont County's is. Of the 7 counties that border it, 6 have more high-potential ground, Clinton County the most at 74.0%.

Share of land by USGS radon potential: Clermont County, the 7 counties bordering it and Ohio
AreaEPA zoneLow potentialModerate potentialHigh potential
Clermont CountyZone 2None100%None
Campbell County, KYZone 2None86.3%13.7%
Brown CountyZone 2None100%None
Bracken County, KYZone 2None99.1%0.9%
Pendleton County, KYZone 1None60.2%39.8%
Hamilton CountyZone 1None88.5%11.5%
Warren CountyZone 1None40.4%59.6%
Clinton CountyZone 1None26.0%74.0%
Ohio88 counties, pooled by land areaVariesNone37.2%62.8%

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

Local help

Clermont County, Local resources

Radon testing and mitigation in Clermont County

Listed radon businesses with an address in Clermont County:

Listed radon professionals by town: Loveland, Milford, Batavia

What Ohio's program says
Phone
614-728-0272
Email
indoor.radon@odh.ohio.gov
Licensing of radon professionals
This program licenses companies and persons directly involved with the radon testing and mitigation industry.

What it means

Clermont County, Questions

Questions about radon in Clermont County

Are radon levels high in Clermont County?

Over the 2008 to 2017 laboratory totals, 50.0% of the radon tests reported to CDC for Clermont County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.0 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 46 reported a higher share; pooled, the state comes to 52.3%.

Which counties border Clermont County?

Clermont County borders 7 counties: Campbell County, KY, Brown County, OH, Bracken County, KY, Pendleton County, KY, Hamilton County, OH, Warren County, OH and Clinton County, OH.

Products

Clermont County, Products

Testing a home in Clermont County

In Clermont County, 50.0% of 1,363 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 52.3% pooled across Ohio. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Clermont County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Clermont County homes, compared

Explore

Clermont County, Bordering counties

Counties bordering Clermont County

Calculated by Radon411

Clermont County, Cities and towns

Cities and towns in Clermont County

The Census Bureau estimates 216,977 residents in Clermont County for July 1, 2025, 8,226 more than in 2020 (+3.9%). That works out to 479 people per square mile of land. Loveland, the largest place on its list (13,288 residents in all), extends beyond Clermont County, so no share of the total is worked out for it. CDC's 1,363 reported tests for 2008 to 2017 work out to 6.3 per 1,000 residents (2025 estimate), close to Ohio's 8.3.

From Loveland to Chilo, CDC publishes no figure by town: each reads Clermont County's.

The cities and towns in Clermont County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Lovelandextends beyond Clermont County13,288LevelCounted whole
Milfordextends beyond Clermont County6,436−2.1%Counted whole
New Richmond2,842+4.0%1.3%
Bethel2,708+3.5%1.2%
Williamsburg2,677+3.6%1.2%
Batavia2,041+2.8%0.9%
Owensville822+3.8%0.4%
Felicity641+3.9%0.3%
Moscow156+2.6%Under 0.1%
Neville95+5.6%Under 0.1%
Chilo68+4.6%Under 0.1%

11 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 Clermont County is counted whole, so it has no share.

Clermont County, Homes

Homes in Clermont County

Of Clermont County's 87,534 homes, 71% are detached houses, against 69% across Ohio; 17% are in buildings of five or more homes. Much of Clermont County is recent building: 25% of its homes have gone up since 2000 and the middle year built is 1986, against 1970 for Ohio. 73% of occupied homes are lived in by their owner (Ohio: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Clermont County, Ohio, 2019 to 2023
HomesClermont CountyOhio
Housing units87,5345,271,573
Detached houses71%69%
In buildings of 5 or more17%15%
Mobile homes5%4%
Built before 196019%38%
Built since 200025%16%
Middle year built19861970
Owner-occupied73%67%

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