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Radon Levels in Edgefield County, South Carolina

EPA puts Edgefield County in Zone 3, its lowest radon zone, and only 12 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). 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

  • Highest bordering

    13.3%

    Aiken County

    Aiken
    13.3%
    Richmond
    0.0%

    4 of 6 neighbours have 30+ tests, 2008 to 2017

  • Nearest county

    13.3%

    Aiken County, 25 miles

    Aiken
    13.3%
    SC
    19.4%

    Share at 4+ pCi/L, 241 tests, 2008 to 2017

  • Ground above low

    1.2%

    17.3 pts below SC

    Edgefield
    1.2%
    SC
    18.5%

    Share of land USGS rates moderate or high potential

  • Tests reported

    12

    Too few for a share

    Edgefield
    12
    Needed
    30

    2008 to 2017, laboratory

  • EPA radon zone

    Zone 3

    Lower potential

    1. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

Read a result for Edgefield County

Starts at EPA's action level

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.

Interpret this readingWhat a fix costs

The data

Edgefield County, At a glance

Edgefield County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Edgefield County as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

USGS geologic potential: Low across 99% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Edgefield County, 2008 to 2017, laboratory

CDC holds 12 reported tests for Edgefield County over the 2008 to 2017 laboratory totals, with a median of 1.2 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Edgefield County beside the counties around it is how this page reads it.

What these figures count

Only 12 tests were reported to CDC for Edgefield County over 2008 to 2017 (laboratory totals), and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor 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

Edgefield County, Compared

Edgefield County radon figures, compared

Calculated by Radon411

CDC's largest figure for Edgefield County rests on 12 tests over the 2008 to 2017 laboratory totals, 3 of them at or above 4 pCi/L, so each test moves its share by 8.3 points and no rank or comparison is drawn from it. Results reached as high as 5.7 pCi/L, with a middle value of 1.2 pCi/L.

Of the counties bordering it, 4 have a figure over the 2008 to 2017 laboratory totals: Aiken County reported the largest share at or above 4 pCi/L, 13.3%, and Richmond County, GA the smallest, 0.0%, with Columbia County, GA at 11.1% and Greenwood County at 7.1% between. Farther out, Lexington County (41 miles away) at 12.5%, Newberry County (41 miles away) at 16.0% and Abbeville County (42 miles away) at 22.7% have figures too. Pooled across 46 South Carolina counties, 19.4% of reported tests reached that level; across every county in the country with a figure, 35.7%.

Statewide for the same period, Oconee County reported the highest share (42.6%) and Florence County the lowest (0.0%). EPA's 1993 map puts Edgefield County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 99% of the county's land low radon potential.

South Carolina, the United States and the counties around Edgefield County, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedian
South Carolina, pooled46 counties, pooled26,48119.4%Not pooled
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled
Oconee Countyhighest in the state2,46942.6%3.3 pCi/L
Florence Countylowest in the state590.0%0.7 pCi/L
Saluda County, SCborders it1816.7%1.1 pCi/L
Aiken County, SCborders it24113.3%1.3 pCi/L
Columbia County, GAborders it6311.1%0.9 pCi/L
Greenwood County, SCborders it1137.1%1.0 pCi/L
McCormick County, SCborders it100.0%1.1 pCi/L
Richmond County, GAborders it320.0%1.4 pCi/L
The nearest South Carolina counties to Edgefield County with 30 or more tests, 2008 to 2017, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Aiken County25 mi24113.3%1.3 pCi/L
Greenwood County28 mi1137.1%1.0 pCi/L
Lexington County41 mi59112.5%0.9 pCi/L
Newberry County41 mi7516.0%1.1 pCi/L
Abbeville County42 mi6622.7%1.8 pCi/L
Laurens County49 mi24413.9%1.3 pCi/L
Richland County63 mi6714.9%0.7 pCi/L
Anderson County64 mi1,73311.1%1.1 pCi/L
Edgefield County ten-year laboratory totals, against South Carolina's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestSouth Carolina, pooledChange from the row before
2008 to 20171225.0%1.2 pCi/L5.7 pCi/L19.4%+8.3 points
2007 to 20161216.7%1.2 pCi/L5.8 pCi/L19.3%−8.3 points
2006 to 2015825.0%1.8 pCi/L5.8 pCi/L19.8%+2.8 points
2005 to 2014922.2%2.0 pCi/L5.8 pCi/L19.8%First on file

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

Edgefield County, Geology

The ground under Edgefield County

Predicted

Most of the ground under Edgefield County is one class on USGS's geologic map: 98.8% of its land is low radon potential, with 1.2% moderate. The map puts 42.0% of Edgefield County in the area it calls Carolina Slate Belt and 29.5% in Little River Thrust Stack, with 2 smaller areas beside them. USGS gives the first a radon index of 8 and the second 7, both in the low band (5 to 8).

USGS's geologic areas under Edgefield County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Carolina Slate Beltamphibolite, granitic gneiss, quartzite, muscovite schist, meta-argillite, metavolcanic rocks.Low842.0%
Little River Thrust StackBiotite and amphibolite gneiss, granite gneiss, mica schist.Low729.5%
Upper and Middle Coastal PlainTertiary coastal plain sandy and silty sediments and marsh deposits.Low827.3%
Carolina and Charlotte Belt GranitesGranite and granite gneissModerate111.2%

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

Edgefield County beside the ground around it

Across South Carolina 0.2% of the land is rated high; none of Edgefield County's is. Of the 6 counties that border it, 2 have more moderate-potential ground, Greenwood County the most at 11.3%.

Share of land by USGS radon potential: Edgefield County, the 6 counties bordering it and South Carolina
AreaEPA zoneLow potentialModerate potentialHigh potential
Edgefield CountyZone 398.8%1.2%None
McCormick CountyZone 399.7%0.3%None
Columbia County, GAZone 3100%NoneNone
Saluda CountyZone 396.4%3.6%None
Aiken CountyZone 3100%NoneNone
Richmond County, GAZone 2100%NoneNone
Greenwood CountyZone 388.7%11.3%None
South Carolina46 counties, pooled by land areaVaries80.8%18.2%0.2%

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

Local help

Edgefield County, Local resources

Radon testing and mitigation in Edgefield County

What South Carolina's program says
Phone
1-800-768-0362
Email
radon@des.sc.gov

What it means

Edgefield County, Questions

Questions about radon in Edgefield County

Are radon levels high in Edgefield County?

Over the 2008 to 2017 laboratory totals, 25.0% of the radon tests reported to CDC for Edgefield County, South Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.2 pCi/L. Of the counties bordering it, 4 have a figure over the 2008 to 2017 laboratory totals: Aiken County reported the largest share at or above 4 pCi/L, 13.3%, and Richmond County, GA the smallest, 0.0%, with Columbia County, GA at 11.1% and Greenwood County at 7.1% between.

Which counties border Edgefield County?

Edgefield County borders 6 counties: McCormick County, SC, Columbia County, GA, Saluda County, SC, Aiken County, SC, Richmond County, GA and Greenwood County, SC.

Products

Edgefield County, Products

Testing a home in Edgefield County

No CDC figure names Edgefield County; the nearest county with one, Aiken County (25 miles away), reported 13.3% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Edgefield County.

Test kits and monitors3

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Best radon monitors for Edgefield County homes, compared

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Edgefield County, Bordering counties

Counties bordering Edgefield County

Calculated by Radon411

Edgefield County, Cities and towns

Cities and towns in Edgefield County

Edgefield County is growing: the Census Bureau puts it at 29,808 residents on July 1, 2025, up 16.1% from 25,674 in 2020. That works out to 60 people per square mile of land. North Augusta, the largest place on its list (26,982 residents in all), extends beyond Edgefield County, so no share of the total is worked out for it. Reported testing is thin here: 12 tests over 2008 to 2017, or 0.4 for every 1,000 residents (2025 estimate), where South Carolina as a whole comes to 4.8.

From North Augusta to Trenton, CDC publishes no figure by town: each reads Edgefield County's.

The cities and towns in Edgefield County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
North Augustaextends beyond Edgefield County26,982+10.3%Counted whole
Edgefield4,182+7.0%14.0%
Johnston2,233+11.7%7.5%
Trenton412+111.3%1.4%

4 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 Edgefield County is counted whole, so it has no share.

Edgefield County, Homes

Homes in Edgefield County

Of Edgefield County's 11,317 homes, 67% are detached houses, against 64% across South Carolina; 25% are mobile homes. Half of its homes were built before 1988, close to South Carolina's 1991: 14% date from before 1960 and 25% from 2000 or later. Owners live in 80% of the occupied homes (South Carolina: 71%), so for most households a test and a fix are their own to order.

Homes in Edgefield County, South Carolina, 2019 to 2023
HomesEdgefield CountySouth Carolina
Housing units11,3172,401,638
Detached houses67%64%
In buildings of 5 or more4%13%
Mobile homes25%15%
Built before 196014%13%
Built since 200025%35%
Middle year built19881991
Owner-occupied80%71%

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