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Radon Levels in Madison County, Georgia

EPA puts Madison County in Zone 2, its middle radon zone, and 26.1% of its 211 reported radon tests (2008 to 2017, laboratory totals) 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

    26.1%

    1.3 pts above GA

    Madison
    26.1%
    Georgia
    24.8%

    211 tests, 2008 to 2017

  • Median result

    2.4pCi/L

    Below action level

    Madison
    2.4 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    211

    23rd of 57 by tests

    Madison
    211
    Fulton
    4,858

    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 Georgia

    26 of 57

    Middle half

    Madison
    26.1%
    Barrow
    48.3%

    By share, of 57 with 30+ tests

Read a result for Madison County

Starts at Madison County's median, 2.4 pCi/L

2.4pCi/L

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

EPA’s reading of 2.4 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. Madison County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Madison County, At a glance

Madison County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Madison 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 Madison County, 2008 to 2017, laboratory

Reported results by concentration band, Madison County, 2008 to 2017, laboratory
Under 2 pCi/L: 44%2 to 4 pCi/L: 30%4 pCi/L and above: 26%

Of 211 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Madison County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L9243.6%
2 to 4 pCi/L6430.3%
4 pCi/L and above5526.1%
What these figures count

These are the 211 tests reported to CDC for Madison 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

Madison County, Compared

Madison County radon figures, compared

Calculated by Radon411

Madison County's 211 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.4 pCi/L and a maximum of 25.0 pCi/L, and 26.1% reached 4 pCi/L. Georgia as a whole (129 Georgia counties, pooled) comes to 24.8%: 1.3 points lower than here.

Among its state's counties it ranks 26th of 57 Georgia counties with 30 or more tests for the same period. Statewide for the same period, Barrow County reported the highest share (48.3%) and Richmond County the lowest (0.0%).

Below the action level, 92 tests (43.6%) came in under 2 pCi/L, against 44.0% statewide, and 64 tests (30.3%) fell between 2 and 4, against 31.2% statewide. CDC's ten-year totals for Madison County went from 479 tests (2005 to 2014) to 211 (2008 to 2017), the share going from 15.0% to 26.1%.

EPA's 1993 zone map puts Madison 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 12.8% in Clarke County to 40.2% in Hart County, with Elbert County and Clarke County below Madison County.

CDC also counts 12 tests taken after mitigation in Madison County for the same period: tests in homes where a fix was already in.

Madison County against Georgia, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Madison County
Madison County21126.1%2.4 pCi/LThis county
Georgia, pooled129 counties, pooled30,15224.8%Not pooled−1.3 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+9.6 points
Barrow Countyhighest in the state32148.3%3.8 pCi/L+22.2 points
Richmond Countylowest in the state320.0%1.4 pCi/L−26.1 points
Hart County, GAborders it10740.2%3.4 pCi/L+14.1 points
Jackson County, GAborders it46040.0%3.2 pCi/L+13.9 points
Franklin County, GAborders it2737.0%2.7 pCi/L+10.9 points
Banks County, GAborders it5735.1%2.8 pCi/L+9.0 points
Oglethorpe County, GAborders it7332.9%2.5 pCi/L+6.8 points
Elbert County, GAborders it14518.6%1.9 pCi/L−7.5 points
Clarke County, GAborders it58412.8%1.5 pCi/L−13.3 points
Where Madison County's reported results fell, 2008 to 2017, laboratory, beside Georgia and the United States
ResultMadison County testsMadison County shareGeorgia shareU.S. shareAgainst Georgia
Under 2 pCi/L9243.6%44.0%39.6%−0.4 points
2 to 4 pCi/L6430.3%31.2%24.7%−0.9 points
4 pCi/L and above5526.1%24.8%35.7%+1.3 points
Madison County ranked among the 57 Georgia counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Fayette County21 of 5787330.5%2.6 pCi/L
Putnam County22 of 573030.0%2.2 pCi/L
Rockdale County23 of 5724729.1%2.3 pCi/L
Jones County24 of 573129.0%2.2 pCi/L
Rabun County25 of 576926.1%2.0 pCi/L
Madison County26 of 5721126.1%2.4 pCi/L
Paulding County27 of 5728926.0%2.3 pCi/L
Newton County28 of 5718625.8%2.1 pCi/L
Stephens County29 of 577925.3%2.2 pCi/L
White County30 of 579125.3%2.7 pCi/L
Bartow County31 of 5717724.9%2.2 pCi/L
Madison County ten-year laboratory totals, against Georgia's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestGeorgia, pooledChange from the row before
2008 to 201721126.1%2.4 pCi/L25.0 pCi/L24.8%+0.8 points
2007 to 201624125.3%2.2 pCi/L26.1 pCi/L23.9%+4.1 points
2006 to 201533521.2%1.8 pCi/L26.1 pCi/L23.7%+6.2 points
2005 to 201447915.0%1.3 pCi/L26.1 pCi/L23.2%First on file

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

Madison County, Geology

The ground under Madison County

Predicted

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

USGS's geologic areas under Madison County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Georgiabama Thrust Stack (South)Schist, amphibolite and granite.Moderate9100%

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

Madison County beside the ground around it

Madison County has more moderate-potential ground than Georgia as a whole: 100% of its land against 26.5%. Of the 7 counties that border it, none has as large a share of moderate-potential ground; Banks County comes nearest at 100%.

Share of land by USGS radon potential: Madison County, the 7 counties bordering it and Georgia
AreaEPA zoneLow potentialModerate potentialHigh potential
Madison CountyZone 2None100%None
Clarke CountyZone 2None100%None
Franklin CountyZone 2None100%None
Oglethorpe CountyZone 216.0%84.0%None
Elbert CountyZone 226.6%73.4%None
Hart CountyZone 2None100%None
Jackson CountyZone 2None100%None
Banks CountyZone 2None100%None
Georgia159 counties, pooled by land areaVaries73.1%26.5%None

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

Local help

Madison County, Local resources

Radon testing and mitigation in Madison County

What Georgia's program says
Licensing of radon professionals
There are no laws mandating a mitigator receive certification in Georgia, however, many mitigators choose to get certified by one of two national programs.

What it means

Madison County, Questions

Questions about radon in Madison County

Are radon levels high in Madison County?

Over the 2008 to 2017 laboratory totals, 26.1% of the radon tests reported to CDC for Madison County, Georgia were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.4 pCi/L. Of 57 Georgia counties with 30 or more tests for the same period, 25 reported a higher share; pooled, the state comes to 24.8%.

Which counties border Madison County?

Madison County borders 7 counties: Clarke County, Franklin County, Oglethorpe County, Elbert County, Hart County, Jackson County and Banks County.

Products

Madison County, Products

Testing a home in Madison County

In Madison County, 26.1% of 211 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 24.8% pooled across Georgia. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Madison County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Madison County homes, compared

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Madison County, Bordering counties

Counties bordering Madison County

Calculated by Radon411

Madison County, Cities and towns

Cities and towns in Madison County

Madison County is growing: the Census Bureau puts it at 32,919 residents on July 1, 2025, up 8.8% from 30,266 in 2020. That works out to 117 people per square mile of land. Royston, the largest place on its list (2,693 residents in all), extends beyond Madison County, so no share of the total is worked out for it. Testing is reported here more often than across the state: CDC's 211 reported tests for 2008 to 2017 come to 6.4 for every 1,000 residents (2025 estimate), against 2.7 for Georgia.

From Royston to Hull, CDC publishes no figure by town: each reads Madison County's.

The cities and towns in Madison County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Roystonextends beyond Madison County2,693+1.9%Counted whole
Comer1,631+6.8%5.0%
Danielsville895+15.3%2.7%
Colbert679+6.8%2.1%
Ila376+9.0%1.1%
Carlton311+18.3%0.9%
Hull248+2.5%0.8%

7 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 Madison County is counted whole, so it has no share.

Madison County, Homes

Homes in Madison County

Of Madison County's 12,371 homes, 66% are detached houses, against 66% across Georgia; 31% are mobile homes. Half of its homes were built before 1990, close to Georgia's 1991: 11% date from before 1960 and 28% from 2000 or later. Owners live in 76% of the occupied homes (Georgia: 65%), so for most households a test and a fix are their own to order.

Homes in Madison County, Georgia, 2019 to 2023
HomesMadison CountyGeorgia
Housing units12,3714,483,873
Detached houses66%66%
In buildings of 5 or moreunder 1%16%
Mobile homes31%8%
Built before 196011%12%
Built since 200028%33%
Middle year built19901991
Owner-occupied76%65%

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