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Radon Levels in Culpeper County, Virginia

EPA puts Culpeper County in Zone 2, its middle radon zone, and high results are common there: 40.1% of the 891 radon tests reported to CDC (2008 to 2017, laboratory totals) came back 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    40.1%

    9.7 pts above VA

    Culpeper
    40.1%
    Virginia
    30.4%

    891 tests, 2008 to 2017

  • Median result

    3.2pCi/L

    Below action level

    Culpeper
    3.2 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    891

    14th of 84 by tests

    Culpeper
    891
    Fairfax
    8,657

    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 Virginia

    27 of 84

    Middle half

    Culpeper
    40.1%
    Russell
    67.3%

    By share, of 84 with 30+ tests

Read a result for Culpeper County

Starts at Culpeper County's median, 3.2 pCi/L

3.2pCi/L

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

EPA’s reading of 3.2 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. Culpeper County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Culpeper County, At a glance

Culpeper County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Culpeper 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 76% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Culpeper County, 2008 to 2017, laboratory
Under 2 pCi/L: 27%2 to 4 pCi/L: 33%4 pCi/L and above: 40%

Of 891 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Culpeper County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L24026.9%
2 to 4 pCi/L29433.0%
4 pCi/L and above35740.1%
What these figures count

These are the 891 tests reported to CDC for Culpeper 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

Culpeper County, Compared

Culpeper County radon figures, compared

Calculated by Radon411

In Culpeper County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (357 of 891) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 4.4 points higher. Across 131 Virginia counties pooled together, 30.4% of tests reached that level, so Culpeper County runs 9.7 points above its state.

Of 6 neighbours with a figure, 2 reported a larger share at or above 4 pCi/L and 4 a smaller one; the spread is 30.2% (Fauquier County) to 44.0% (Madison County). By share, Culpeper County is 27th of 84 Virginia counties with 30 or more tests for the same period.

Half the tests came in under 3.2 pCi/L and half over it; the single highest reached 54.7 pCi/L. Below the action level, 240 tests (26.9%) came in under 2 pCi/L, against 44.7% statewide, and 294 tests (33.0%) fell between 2 and 4, against 24.9% statewide.

Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 40.1% share point the same way here. USGS geology rates 76% of the county's land moderate radon potential. CDC also counts 108 tests taken after mitigation in Culpeper County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Culpeper County went from 506 tests (2005 to 2014) to 891 (2008 to 2017), the share going from 41.3% to 40.1%.

Culpeper County against Virginia, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Culpeper County
Culpeper County89140.1%3.2 pCi/LThis county
Virginia, pooled131 counties, pooled53,19930.4%Not pooled−9.7 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−4.4 points
Russell Countyhighest in the state4967.3%6.7 pCi/L+27.2 points
Norfolk citylowest in the state732.7%0.5 pCi/L−37.4 points
Madison County, VAborders it18444.0%3.5 pCi/L+3.9 points
Rappahannock County, VAborders it13741.6%3.3 pCi/L+1.5 points
Orange County, VAborders it46236.1%2.8 pCi/L−4.0 points
Spotsylvania County, VAborders it1,87234.2%2.7 pCi/L−5.9 points
Stafford County, VAborders it2,75831.4%2.5 pCi/L−8.7 points
Fauquier County, VAborders it1,19930.2%2.5 pCi/L−9.9 points
Where Culpeper County's reported results fell, 2008 to 2017, laboratory, beside Virginia and the United States
ResultCulpeper County testsCulpeper County shareVirginia shareU.S. shareAgainst Virginia
Under 2 pCi/L24026.9%44.7%39.6%−17.8 points
2 to 4 pCi/L29433.0%24.9%24.7%+8.1 points
4 pCi/L and above35740.1%30.4%35.7%+9.7 points
Culpeper County ranked among the 84 Virginia counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Floyd County22 of 845442.6%3.3 pCi/L
Botetourt County23 of 8457542.1%3.3 pCi/L
Radford city24 of 849841.8%3.2 pCi/L
Rappahannock County25 of 8413741.6%3.3 pCi/L
Tazewell County26 of 8437240.3%2.8 pCi/L
Culpeper County27 of 8489140.1%3.2 pCi/L
Alleghany County28 of 845040.0%3.0 pCi/L
Prince Edward County28 of 845040.0%2.5 pCi/L
Campbell County30 of 8436539.7%3.2 pCi/L
Brunswick County31 of 843839.5%2.8 pCi/L
Pittsylvania County32 of 8424238.4%3.0 pCi/L
Culpeper County ten-year laboratory totals, against Virginia's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestVirginia, pooledChange from the row before
2008 to 201789140.1%3.2 pCi/L54.7 pCi/L30.4%−0.9 points
2007 to 201674441.0%3.3 pCi/L49.9 pCi/L30.6%−1.2 points
2006 to 201562542.2%3.4 pCi/L49.9 pCi/L30.7%+0.9 points
2005 to 201450641.3%3.3 pCi/L49.9 pCi/L30.3%First on file

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

Culpeper County, Geology

The ground under Culpeper County

Predicted

Most of the ground under Culpeper County is one class on USGS's geologic map: 75.7% of its land is moderate radon potential, with 24.3% high. The map puts 44.1% of Culpeper County in the area it calls Blue Ridge and 31.6% in Mesozoic Basins, with one smaller area beside them. USGS gives the first a radon index of 10 and the second 11, both in the moderate band (9 to 11).

USGS's geologic areas under Culpeper County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Blue RidgeGranite, pegmatite, monazite, schist, and gneiss.Moderate1044.1%
Mesozoic BasinsSandstone, siltstone and lacustrine black shale.Moderate1131.6%
Inner PiedmontGranite, pegmatites, granitic gneiss, schist and gneiss, slate, and phyllite.High1224.3%

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

Culpeper County beside the ground around it

Virginia as a whole has more high-potential ground than Culpeper County: 47.9% of its land, against 24.3% here. Of the 6 counties that border it, 3 have more high-potential ground, Spotsylvania County the most at 88.1%.

Share of land by USGS radon potential: Culpeper County, the 6 counties bordering it and Virginia
AreaEPA zoneLow potentialModerate potentialHigh potential
Culpeper CountyZone 2None75.7%24.3%
Orange CountyZone 1None13.2%86.8%
Madison CountyZone 2None99.5%0.5%
Rappahannock CountyZone 2None100%None
Fauquier CountyZone 2None83.8%16.2%
Spotsylvania CountyZone 111.9%None88.1%
Stafford CountyZone 146.7%None51.4%
Virginia133 counties, pooled by land areaVaries20.6%30.0%47.9%

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

Local help

Culpeper County, Local resources

Radon testing and mitigation in Culpeper County

What Virginia's program says
Phone
(804) 864-8161
Email
Radon@vdh.virginia.gov
Licensing of radon professionals
The Code of Virginia requires that Radon testers and mitigators be currently certified by either the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).

What it means

Culpeper County, Questions

Questions about radon in Culpeper County

Are radon levels high in Culpeper County?

Over the 2008 to 2017 laboratory totals, 40.1% of the radon tests reported to CDC for Culpeper County, Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.2 pCi/L. Of 84 Virginia counties with 30 or more tests for the same period, 26 reported a higher share; pooled, the state comes to 30.4%.

Which counties border Culpeper County?

Culpeper County borders 6 counties: Orange County, Madison County, Rappahannock County, Fauquier County, Spotsylvania County and Stafford County.

Products

Culpeper County, Products

Testing a home in Culpeper County

In Culpeper County, 40.1% of 891 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.4% pooled across Virginia. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Culpeper County; a long-term test tells the year-round average.

Test kits and monitors3

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Best radon monitors for Culpeper County homes, compared

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Culpeper County, Bordering counties

Counties bordering Culpeper County

Calculated by Radon411

Culpeper County, Cities and towns

Cities and towns in Culpeper County

Culpeper County is growing: the Census Bureau puts it at 57,666 residents on July 1, 2025, up 9.3% from 52,764 in 2020. That works out to 152 people per square mile of land. Culpeper, its one incorporated place, has 22,074 residents, 38.3% of the total. Testing is reported here more often than across the state: CDC's 891 reported tests for 2008 to 2017 come to 15.5 for every 1,000 residents (2025 estimate), against 6.0 for Virginia.

Culpeper is the one incorporated place here; CDC publishes no figure by town, so it reads Culpeper County's.

Culpeper, Culpeper County: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Culpeper22,074+9.5%38.3%

One incorporated place, 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).

Culpeper County, Homes

Homes in Culpeper County

Culpeper County is a place of houses on their own lots: 82% of its 19,529 homes are detached single-family houses, against 61% across Virginia. Much of Culpeper County is recent building: 38% of its homes have gone up since 2000 and the middle year built is 1992, against 1984 for Virginia. 75% of occupied homes are lived in by their owner (Virginia: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Culpeper County, Virginia, 2019 to 2023
HomesCulpeper CountyVirginia
Housing units19,5293,654,784
Detached houses82%61%
In buildings of 5 or more9%19%
Mobile homes2%4%
Built before 196013%19%
Built since 200038%25%
Middle year built19921984
Owner-occupied75%67%

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