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Radon Levels in Granville County, North Carolina

EPA puts Granville County in Zone 3, its lowest radon zone, and only 1 radon test from it is on file with CDC (2022). 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

    10.5%

    12.1 pts below NC

    Granville
    10.5%
    NC
    22.6%

    153 tests, 2008 to 2017

  • Median result

    0.8pCi/L

    Below action level

    Granville
    0.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    153

    53rd of 75 by tests

    Granville
    153
    Wake
    9,694

    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 NC

    52 of 75

    Middle half

    Granville
    10.5%
    Transylvania
    47.8%

    By share, of 75 with 30+ tests

Read a result for Granville County

Starts at Granville County's median, 0.8 pCi/L

0.8pCi/L

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

EPA’s reading of 0.8 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. Granville County's median reported result, 2008 to 2017.

Interpret this reading

The data

Granville County, At a glance

Granville County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Granville 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 88% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Granville County, 2022

Share of reported tests at or above 4 pCi/L, by year, Granville County
Share of reported tests at or above 4 pCi/L, by year, Granville County
YearShare of reported tests at or above 4 pCi/L
20145.6%
20200.0%
2021100.0%
20220.0%

2022: 0.0%. Across these years the share ran from 0.0% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 1 test was reported to CDC for Granville County over 2022, 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: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).

How to read these figures

Granville County, Compared

Granville County radon figures, compared

Calculated by Radon411

Granville County reports fewer high tests than North Carolina overall. 10.5% of its 153 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 12.1 points below the 22.6% pooled from 99 North Carolina counties.

The newest figure, in 2022, counts only 1 test (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 153-test figure.

Ordered from highest share down, it comes 52nd of 75 North 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%; Granville County sits 25.2 points below it.

Next door, the shares run from 4.3% in Durham County to 37.9% in Mecklenburg County, VA, with Wake County and Durham County below Granville County. Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 10.5% share point the same way here.

Half the tests came in under 0.8 pCi/L and half over it; the single highest reached 13.0 pCi/L. The rest split 74.5% under 2 pCi/L and 15.0% from 2 to 4 (North Carolina: 55.6% and 21.8%).

The busiest year on file was 2014, with 18 tests reported; the quietest, 2022, had 1.

Granville County against North Carolina, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Granville County
Granville County15310.5%0.8 pCi/LThis county
North Carolina, pooled99 counties, pooled73,13922.6%Not pooled+12.1 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+25.2 points
Transylvania Countyhighest in the state3,86247.8%3.7 pCi/L+37.3 points
Nash Countylowest in the state300.0%0.2 pCi/L−10.5 points
Mecklenburg County, VAborders it6637.9%3.0 pCi/L+27.4 points
Franklin County, NCborders it20419.1%1.4 pCi/L+8.6 points
Halifax County, VAborders it3718.9%2.2 pCi/L+8.4 points
Person County, NCborders it19017.4%1.3 pCi/L+6.9 points
Vance County, NCborders it10914.7%1.5 pCi/L+4.2 points
Wake County, NCborders it9,6949.6%1.0 pCi/L−0.9 points
Durham County, NCborders it1,5704.3%0.7 pCi/L−6.2 points
Where Granville County's reported results fell, 2008 to 2017, laboratory, beside North Carolina and the United States
ResultGranville County testsGranville County shareNorth Carolina shareU.S. shareAgainst North Carolina
Under 2 pCi/L11474.5%55.6%39.6%+18.9 points
2 to 4 pCi/L2315.0%21.8%24.7%−6.8 points
4 pCi/L and above1610.5%22.6%35.7%−12.1 points
Granville County ranked among the 75 North 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
Caswell County47 of 754714.9%1.6 pCi/L
Vance County48 of 7510914.7%1.5 pCi/L
Union County49 of 7583611.2%1.1 pCi/L
Chatham County50 of 7558710.9%1.1 pCi/L
Orange County51 of 751,09510.7%1.1 pCi/L
Granville County52 of 7515310.5%0.8 pCi/L
Wake County53 of 759,6949.6%1.0 pCi/L
Cabarrus County54 of 758808.8%1.0 pCi/L
Mecklenburg County55 of 753,7538.5%0.9 pCi/L
Johnston County56 of 756688.2%0.7 pCi/L
Wayne County57 of 75498.2%0.6 pCi/L
Granville County radon tests by year, against North Carolina's pooled share
YearTestsAt or above 4 pCi/LMedianHighestNorth Carolina, pooledChange from the row before
202210.0%1.0 pCi/L1.0 pCi/L10.7%−100.0 points
20211100.0%4.0 pCi/L4.0 pCi/L14.9%+100.0 points
2020150.0%0.7 pCi/L3.4 pCi/L21.1%−5.6 points
2014185.6%0.1 pCi/L8.1 pCi/L21.9%First on file

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

Granville County, Geology

The ground under Granville County

Predicted

Most of the ground under Granville County is one class on USGS's geologic map: 87.8% of its land is low radon potential, with 12.2% moderate. The map puts 66.8% of Granville County in the area it calls Carolina Slate Belt and 21.1% in Sanford-Durham Sub-Basins, with one smaller area beside them. USGS gives the first a radon index of 6 and the second 8, both in the low band (5 to 8).

USGS's geologic areas under Granville County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Carolina Slate BeltFelsic metavolcanics, intermediate volcanics, metamudstone, argillite, and epiclastic rocks.Low666.8%
Sanford-Durham Sub-BasinsArkosic sandstone, siltstone and conglomerate.Low821.1%
Raleigh BeltProterozoic through Cambrian biotite gneiss and mica schist.Moderate1112.2%

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

Granville County beside the ground around it

Across North Carolina 1.3% of the land is rated high; none of Granville County's is. Of the 7 counties that border it, 1 has more high-potential ground, Mecklenburg County, VA the most at 38.4%.

Share of land by USGS radon potential: Granville County, the 7 counties bordering it and North Carolina
AreaEPA zoneLow potentialModerate potentialHigh potential
Granville CountyZone 387.8%12.2%None
Vance CountyZone 236.7%63.3%None
Person CountyZone 387.2%12.8%None
Durham CountyZone 396.7%3.3%None
Franklin CountyZone 20.2%99.8%None
Mecklenburg County, VAZone 20.2%61.4%38.4%
Halifax County, VAZone 20.2%99.8%None
Wake CountyZone 220.6%79.4%None
North Carolina100 counties, pooled by land areaVaries64.8%33.0%1.3%

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

Local help

Granville County, Local resources

Radon testing and mitigation in Granville County

What North Carolina's program says
Licensing of radon professionals
The North Carolina Radon Program is presently developing a Radon Proficiency Program as directed by Session Law 2023-91 House Bill 782 .

What it means

Granville County, Questions

Questions about radon in Granville County

Are radon levels high in Granville County?

In 2022, 0.0% of the radon tests reported to CDC for Granville County, North Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.0 pCi/L. Of 75 North Carolina counties with 30 or more tests for the same period, 51 reported a higher share; pooled, the state comes to 22.6%.

Which counties border Granville County?

Granville County borders 7 counties: Vance County, NC, Person County, NC, Durham County, NC, Franklin County, NC, Mecklenburg County, VA, Halifax County, VA and Wake County, NC.

Products

Granville County, Products

Testing a home in Granville County

In Granville County, 10.5% of 153 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 22.6% pooled across North 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 Granville County.

Test kits and monitors3

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Best radon monitors for Granville County homes, compared

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Granville County, Bordering counties

Counties bordering Granville County

Calculated by Radon411

Granville County, Cities and towns

Cities and towns in Granville County

The Census Bureau estimates 61,421 residents in Granville County for July 1, 2025, 1,243 more than in 2020 (+2.1%). That works out to 115 people per square mile of land. No town dominates: Oxford, the largest, has 8,985 residents, 14.6% of the total. Together its 5 incorporated places hold 38.3% of those residents; the other 61.7% live outside any of them. Reported testing is thin here: 153 tests over 2008 to 2017, or 2.5 for every 1,000 residents (2025 estimate), where North Carolina as a whole comes to 6.5.

From Oxford to Stovall, CDC publishes no figure by town: each reads Granville County's.

The cities and towns in Granville County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Oxford8,985+2.3%14.6%
Butner8,112+1.9%13.2%
Creedmoor5,046+2.7%8.2%
Stem1,023+2.6%1.7%
Stovall333+1.8%0.5%

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).

Granville County, Homes

Homes in Granville County

Of Granville County's 24,582 homes, 73% are detached houses, against 65% across North Carolina; 18% are mobile homes. Half of its homes were built before 1990, close to North Carolina's 1990: 16% date from before 1960 and 33% from 2000 or later. Owners live in 77% of the occupied homes (North Carolina: 66%), so for most households a test and a fix are their own to order.

Homes in Granville County, North Carolina, 2019 to 2023
HomesGranville CountyNorth Carolina
Housing units24,5824,815,195
Detached houses73%65%
In buildings of 5 or more4%14%
Mobile homes18%11%
Built before 196016%14%
Built since 200033%33%
Middle year built19901990
Owner-occupied77%66%

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