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Radon Levels in Fairfield County, South Carolina

EPA puts Fairfield County in Zone 3, its lowest radon zone, and only 27 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

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  • Share at 4+ pCi/L

    16.3%

    3.0 pts below SC

    Fairfield
    16.3%
    SC
    19.3%

    43 tests, 2007 to 2016

  • Median result

    1.2pCi/L

    Below action level

    Fairfield
    1.2 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2007 to 2016

  • Tests reported

    43

    25th of 26 by tests

    Fairfield
    43
    Greenville
    11,402

    Reported to CDC before any fix, 2007 to 2016

  • 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

    6 of 26

    Top quarter

    Fairfield
    16.3%
    Oconee
    43.1%

    By share, of 26 with 30+ tests

Read a result for Fairfield County

Starts at Fairfield County's median, 1.2 pCi/L

1.2pCi/L

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

EPA’s reading of 1.2 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. Fairfield County's median reported result, 2007 to 2016.

Interpret this reading

The data

Fairfield County, At a glance

Fairfield County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Fairfield 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 79% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

CDC holds 27 reported tests for Fairfield County over the 2008 to 2017 laboratory totals, with a median of 0.9 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Fairfield County beside the counties around it is how this page reads it.

What these figures count

Only 27 tests were reported to CDC for Fairfield 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

Fairfield County, Compared

Fairfield County radon figures, compared

Calculated by Radon411

Fairfield County's 43 reported tests over the 2007 to 2016 laboratory totals had a middle value of 1.2 pCi/L and a maximum of 9.8 pCi/L, and 16.3% reached 4 pCi/L. South Carolina as a whole (46 South Carolina counties, pooled) comes to 19.3%: 3.0 points higher than here.

The newest figure, over the 2008 to 2017 laboratory totals, counts only 27 tests (7.4% at or above 4 pCi/L), too few to compare, so this reading uses the 43-test figure.

Among its state's counties it ranks 6th of 26 South Carolina counties with 30 or more tests for the same period. Statewide for the same period, Oconee County reported the highest share (43.1%) and Florence County the lowest (0.0%).

Below the action level, 29 tests (67.4%) came in under 2 pCi/L, against 58.0% statewide, and 7 tests (16.3%) fell between 2 and 4, against 22.6% statewide. CDC's ten-year totals for Fairfield County went from 42 tests (2005 to 2014) to 27 (2008 to 2017), the share going from 16.7% to 7.4%.

EPA's 1993 zone map puts Fairfield County in Zone 3, a predicted county average under 2 pCi/L. USGS geology rates 79% of the county's land low radon potential.

Next door, the shares run from 4.2% in Richland County to 15.5% in Lancaster County, with Lancaster County, Newberry County and Kershaw County below Fairfield County.

Fairfield County against South Carolina, the United States and nearby counties, 2007 to 2016, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Fairfield County
Fairfield County4316.3%1.2 pCi/LThis county
South Carolina, pooled46 counties, pooled25,75519.3%Not pooled+3.0 points
United States, pooled2,666 counties, pooled1,939,02535.8%Not pooled+19.5 points
Oconee Countyhighest in the state2,34043.1%3.3 pCi/L+26.8 points
Florence Countylowest in the state540.0%0.6 pCi/L−16.3 points
Chester County, SCborders it2020.0%1.1 pCi/L+3.7 points
Lancaster County, SCborders it32915.5%1.8 pCi/L−0.8 points
Newberry County, SCborders it8812.5%1.1 pCi/L−3.8 points
Kershaw County, SCborders it844.8%0.6 pCi/L−11.5 points
Richland County, SCborders it9254.2%0.7 pCi/L−12.1 points
Union County, SCborders it270.0%1.0 pCi/L−16.3 points
Where Fairfield County's reported results fell, 2007 to 2016, laboratory, beside South Carolina and the United States
ResultFairfield County testsFairfield County shareSouth Carolina shareU.S. shareAgainst South Carolina
Under 2 pCi/L2967.4%58.0%39.6%+9.4 points
2 to 4 pCi/L716.3%22.6%24.6%−6.3 points
4 pCi/L and above716.3%19.3%35.8%−3.0 points
Fairfield County ranked among the 26 South Carolina counties with 30 or more tests, by share at or above 4 pCi/L, 2007 to 2016, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Oconee County1 of 262,34043.1%3.3 pCi/L
Pickens County2 of 261,58223.7%1.8 pCi/L
Abbeville County3 of 266722.4%1.4 pCi/L
Greenville County4 of 2611,40219.9%1.8 pCi/L
Spartanburg County5 of 263,10419.9%1.8 pCi/L
Fairfield County6 of 264316.3%1.2 pCi/L
Lancaster County7 of 2632915.5%1.8 pCi/L
Cherokee County8 of 2614914.8%1.7 pCi/L
Laurens County9 of 2624614.2%1.3 pCi/L
York County10 of 261,42212.5%1.1 pCi/L
Newberry County11 of 268812.5%1.1 pCi/L
Fairfield 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 2017277.4%0.9 pCi/L9.8 pCi/L19.4%−8.9 points
2007 to 20164316.3%1.2 pCi/L9.8 pCi/L19.3%−0.4 points
2006 to 20154216.7%1.2 pCi/L9.8 pCi/L19.8%Level
2005 to 20144216.7%1.1 pCi/L9.8 pCi/L19.8%First on file

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

Fairfield County, Geology

The ground under Fairfield County

Predicted

Most of the ground under Fairfield County is one class on USGS's geologic map: 79.2% of its land is low radon potential, with 20.8% moderate. The map puts 47.6% of Fairfield County in the area it calls Carolina Slate Belt and 30.6% in Charlotte 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 Fairfield County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Carolina Slate Beltamphibolite, granitic gneiss, quartzite, muscovite schist, meta-argillite, metavolcanic rocks.Low847.6%
Charlotte BeltBiotite gneiss and schist, metavolcanic rocks, mica gneiss.Low830.6%
Carolina and Charlotte Belt GranitesGranite and granite gneissModerate1120.8%
Upper and Middle Coastal PlainTertiary coastal plain sandy and silty sediments and marsh deposits.Low81.0%

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

Fairfield County beside the ground around it

Across South Carolina 0.2% of the land is rated high; none of Fairfield County's is. Of the 6 counties that border it, 1 has more moderate-potential ground, Union County the most at 53.6%.

Share of land by USGS radon potential: Fairfield County, the 6 counties bordering it and South Carolina
AreaEPA zoneLow potentialModerate potentialHigh potential
Fairfield CountyZone 379.2%20.8%None
Chester CountyZone 384.0%16.0%None
Richland CountyZone 399.5%0.5%None
Kershaw CountyZone 388.7%11.3%None
Newberry CountyZone 381.0%19.0%None
Lancaster CountyZone 383.7%16.3%None
Union CountyZone 346.4%53.6%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

Fairfield County, Local resources

Radon testing and mitigation in Fairfield County

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

What it means

Fairfield County, Questions

Questions about radon in Fairfield County

Are radon levels high in Fairfield County?

Over the 2008 to 2017 laboratory totals, 7.4% of the radon tests reported to CDC for Fairfield County, South Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.9 pCi/L. Of 26 South Carolina counties with 30 or more tests for the same period, 5 reported a higher share; pooled, the state comes to 19.3%.

Which counties border Fairfield County?

Fairfield County borders 6 counties: Chester County, Richland County, Kershaw County, Newberry County, Lancaster County and Union County.

Products

Fairfield County, Products

Testing a home in Fairfield County

In Fairfield County, 16.3% of 43 tests reported to CDC over the 2007 to 2016 laboratory totals reached 4 pCi/L, against 19.3% 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 Fairfield County.

Test kits and monitors3

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Best radon monitors for Fairfield County homes, compared

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Fairfield County, Bordering counties

Counties bordering Fairfield County

Calculated by Radon411

Fairfield County, Cities and towns

Cities and towns in Fairfield County

About 20,340 people live in Fairfield County by the Census Bureau's estimate for July 1, 2025, 552 fewer than in 2020 (−2.6%). That works out to 30 people per square mile of land. Blythewood, the largest place on its list (7,233 residents in all), extends beyond Fairfield County, so no share of the total is worked out for it. Reported testing is thin here: 43 tests over 2007 to 2016, or 2.1 for every 1,000 residents (2025 estimate), where South Carolina as a whole comes to 4.6.

From Blythewood to Jenkinsville, CDC publishes no figure by town: each reads Fairfield County's.

The cities and towns in Fairfield County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Blythewoodextends beyond Fairfield County7,233+49.1%Counted whole
Winnsboro3,305−3.5%16.2%
Ridgeway254−4.5%1.2%
Jenkinsville40Level0.2%

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 Fairfield County is counted whole, so it has no share.

Fairfield County, Homes

Homes in Fairfield County

Of Fairfield County's 10,957 homes, 69% are detached houses, against 64% across South Carolina; 24% are mobile homes. The homes are older than South Carolina's as a whole: half were built before 1982 (1991 for South Carolina), and 17% date from before 1960. Owners live in 76% of the occupied homes (South Carolina: 71%), so for most households a test and a fix are their own to order.

Homes in Fairfield County, South Carolina, 2019 to 2023
HomesFairfield CountySouth Carolina
Housing units10,9572,401,638
Detached houses69%64%
In buildings of 5 or more2%13%
Mobile homes24%15%
Built before 196017%13%
Built since 200019%35%
Middle year built19821991
Owner-occupied76%71%

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