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Radon Levels in Greenwood County, South Carolina

EPA puts Greenwood County in Zone 3, its lowest radon zone, and most reported tests there come back low, though 7.1% of 113 (2008 to 2017, laboratory totals) reached 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

    7.1%

    12.3 pts below SC

    Greenwood
    7.1%
    SC
    19.4%

    113 tests, 2008 to 2017

  • Median result

    1.0pCi/L

    Below action level

    Greenwood
    1.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    113

    15th of 24 by tests

    Greenwood
    113
    Greenville
    12,004

    Reported to CDC before any fix, 2008 to 2017

  • 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

  • Rank in SC

    15 of 24

    Middle half

    Greenwood
    7.1%
    Oconee
    42.6%

    By share, of 24 with 30+ tests

Read a result for Greenwood County

Starts at Greenwood County's median, 1.0 pCi/L

1.0pCi/L

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

EPA’s reading of 1.0 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. Greenwood County's median reported result, 2008 to 2017.

Interpret this reading

The data

Greenwood County, At a glance

Greenwood County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Greenwood 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 89% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Greenwood County, 2008 to 2017, laboratory
Under 2 pCi/L: 80%2 to 4 pCi/L: 13%4 pCi/L and above: 7%

Of 113 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Greenwood County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L9079.6%
2 to 4 pCi/L1513.3%
4 pCi/L and above87.1%
What these figures count

These are the 113 tests reported to CDC for Greenwood 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

Greenwood County, Compared

Greenwood County radon figures, compared

Calculated by Radon411

Greenwood County reports fewer high tests than South Carolina overall. 7.1% of its 113 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 12.3 points below the 19.4% pooled from 46 South Carolina counties.

Ordered from highest share down, it comes 15th of 24 South Carolina counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Greenwood County sits 28.6 points below it.

Next door, the shares run from 13.9% in Laurens County to 22.7% in Abbeville County. Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 7.1% share point the same way here.

Half the tests came in under 1.0 pCi/L and half over it; the single highest reached 22.4 pCi/L. The rest split 79.6% under 2 pCi/L and 13.3% from 2 to 4 (South Carolina: 57.4% and 23.1%).

CDC's ten-year totals for Greenwood County went from 125 tests (2005 to 2014) to 113 (2008 to 2017), the share going from 6.4% to 7.1%.

Greenwood County against South Carolina, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Greenwood County
Greenwood County1137.1%1.0 pCi/LThis county
South Carolina, pooled46 counties, pooled26,48119.4%Not pooled+12.3 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+28.6 points
Oconee Countyhighest in the state2,46942.6%3.3 pCi/L+35.5 points
Florence Countylowest in the state590.0%0.7 pCi/L−7.1 points
Edgefield County, SCborders it1225.0%1.2 pCi/L+17.9 points
Abbeville County, SCborders it6622.7%1.8 pCi/L+15.6 points
Saluda County, SCborders it1816.7%1.1 pCi/L+9.6 points
Newberry County, SCborders it7516.0%1.1 pCi/L+8.9 points
Laurens County, SCborders it24413.9%1.3 pCi/L+6.8 points
McCormick County, SCborders it100.0%1.1 pCi/L−7.1 points
Where Greenwood County's reported results fell, 2008 to 2017, laboratory, beside South Carolina and the United States
ResultGreenwood County testsGreenwood County shareSouth Carolina shareU.S. shareAgainst South Carolina
Under 2 pCi/L9079.6%57.4%39.6%+22.2 points
2 to 4 pCi/L1513.3%23.1%24.7%−9.8 points
4 pCi/L and above87.1%19.4%35.7%−12.3 points
Greenwood County ranked among the 24 South Carolina counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
York County10 of 241,41213.6%1.2 pCi/L
Aiken County11 of 2424113.3%1.3 pCi/L
Lexington County12 of 2459112.5%0.9 pCi/L
Sumter County13 of 244211.9%1.3 pCi/L
Anderson County14 of 241,73311.1%1.1 pCi/L
Greenwood County15 of 241137.1%1.0 pCi/L
Orangeburg County16 of 24535.7%0.9 pCi/L
Kershaw County17 of 24605.0%0.7 pCi/L
Richland County18 of 246714.9%0.7 pCi/L
Dorchester County19 of 241044.8%1.0 pCi/L
Berkeley County20 of 24994.0%0.7 pCi/L
Greenwood 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 20171137.1%1.0 pCi/L22.4 pCi/L19.4%−1.1 points
2007 to 20161108.2%1.0 pCi/L22.4 pCi/L19.3%−0.1 points
2006 to 20151208.3%1.0 pCi/L22.4 pCi/L19.8%+1.9 points
2005 to 20141256.4%1.0 pCi/L22.4 pCi/L19.8%First on file

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

Greenwood County, Geology

The ground under Greenwood County

Predicted

Most of the ground under Greenwood County is one class on USGS's geologic map: 88.7% of its land is low radon potential, with 11.3% moderate. The map puts 58.7% of Greenwood County in the area it calls Charlotte Belt and 30.0% in Carolina Slate Belt, with 2 smaller areas beside them. USGS gives both a radon index of 8, in the low band (5 to 8).

USGS's geologic areas under Greenwood County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Charlotte BeltBiotite gneiss and schist, metavolcanic rocks, mica gneiss.Low858.7%
Carolina Slate Beltamphibolite, granitic gneiss, quartzite, muscovite schist, meta-argillite, metavolcanic rocks.Low830.0%
Inner Piedmont BeltProterozoic through Cambrian biotite gneiss and schist, and mica schist.Moderate118.1%
Carolina and Charlotte Belt GranitesGranite and granite gneissModerate113.2%

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

Greenwood County beside the ground around it

Across South Carolina 0.2% of the land is rated high; none of Greenwood County's is. Of the 6 counties that border it, 3 have more moderate-potential ground, Laurens County the most at 57.6%.

Share of land by USGS radon potential: Greenwood County, the 6 counties bordering it and South Carolina
AreaEPA zoneLow potentialModerate potentialHigh potential
Greenwood CountyZone 388.7%11.3%None
Saluda CountyZone 396.4%3.6%None
Abbeville CountyZone 249.6%50.4%None
Laurens CountyZone 242.4%57.6%None
McCormick CountyZone 399.7%0.3%None
Newberry CountyZone 381.0%19.0%None
Edgefield CountyZone 398.8%1.2%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

Greenwood County, Local resources

Radon testing and mitigation in Greenwood County

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

What it means

Greenwood County, Questions

Questions about radon in Greenwood County

Are radon levels high in Greenwood County?

Over the 2008 to 2017 laboratory totals, 7.1% of the radon tests reported to CDC for Greenwood County, South Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.0 pCi/L. Of 24 South Carolina counties with 30 or more tests for the same period, 14 reported a higher share; pooled, the state comes to 19.4%.

Which counties border Greenwood County?

Greenwood County borders 6 counties: Saluda County, Abbeville County, Laurens County, McCormick County, Newberry County and Edgefield County.

Products

Greenwood County, Products

Testing a home in Greenwood County

In Greenwood County, 7.1% of 113 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 19.4% pooled across South Carolina. 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 Greenwood County.

Test kits and monitors3

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Best radon monitors for Greenwood County homes, compared

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Greenwood County, Bordering counties

Counties bordering Greenwood County

Calculated by Radon411

Greenwood County, Cities and towns

Cities and towns in Greenwood County

The Census Bureau estimates 70,379 residents in Greenwood County for July 1, 2025, 1,050 more than in 2020 (+1.5%). That works out to 154 people per square mile of land. Its largest town, Greenwood, has 22,745 residents, 32.3% of the total. Reported testing is thin here: 113 tests over 2008 to 2017, or 1.6 for every 1,000 residents (2025 estimate), where South Carolina as a whole comes to 4.8.

From Greenwood to Troy, CDC publishes no figure by town: each reads Greenwood County's.

The cities and towns in Greenwood County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Greenwood22,745+1.1%32.3%
Ninety Six2,089+0.6%3.0%
Ware Shoalsextends beyond Greenwood County1,733+1.8%Counted whole
Hodges161+1.9%0.2%
Troy87+3.6%0.1%

5 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 Greenwood County is counted whole, so it has no share.

Greenwood County, Homes

Homes in Greenwood County

Of Greenwood County's 31,549 homes, 67% are detached houses, against 64% across South Carolina; 12% are mobile homes. The homes are older than South Carolina's as a whole: half were built before 1976 (1991 for South Carolina), and 26% date from before 1960. 66% of occupied homes are lived in by their owner (South Carolina: 71%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Greenwood County, South Carolina, 2019 to 2023
HomesGreenwood CountySouth Carolina
Housing units31,5492,401,638
Detached houses67%64%
In buildings of 5 or more11%13%
Mobile homes12%15%
Built before 196026%13%
Built since 200018%35%
Middle year built19761991
Owner-occupied66%71%

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