Skip to content
RADON411

Locations and reports

Radon Levels in Clay County, West Virginia

EPA puts Clay County in Zone 2, its middle radon zone, and only 1 radon test from it is 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

    20.6%

    Kanawha County

    Kanawha
    20.6%

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

  • Nearest county

    20.6%

    Kanawha County, 26 miles

    Kanawha
    20.6%
    WV
    37.5%

    Share at 4+ pCi/L, 247 tests, 2008 to 2017

  • Ground above low

    98.3%

    12.3 pts above WV

    Clay
    98.3%
    WV
    86.0%

    Share of land USGS rates moderate or high potential

  • Tests reported

    2

    Too few for a share

    Clay
    2
    Needed
    30

    2006 to 2015, laboratory

  • 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

Read a result for Clay 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

Clay County, At a glance

Clay County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Clay 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 98% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

CDC holds 1 reported test for Clay County over the 2008 to 2017 laboratory totals, a result of 0.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Clay County beside the counties around it is how this page reads it.

What these figures count

Only 1 test was reported to CDC for Clay 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

Clay County, Compared

Clay County radon figures, compared

Calculated by Radon411

CDC's largest figure for Clay County rests on 2 tests over the 2006 to 2015 laboratory totals, 1 of them at or above 4 pCi/L, so each test moves its share by 50.0 points and no rank or comparison is drawn from it. Results reached as high as 4.6 pCi/L, with a middle value of 2.4 pCi/L.

Kanawha County, the one bordering county with a figure over the 2008 to 2017 laboratory totals, reported 20.6% of its tests at or above 4 pCi/L. Farther out, Putnam County (45 miles away) at 23.1%, Raleigh County (49 miles away) at 16.7% and Greenbrier County (49 miles away) at 52.3% have figures too. Pooled across 55 West Virginia counties, 37.5% of reported tests reached that level; across every county in the country with a figure, 35.7%.

Statewide for the same period, Morgan County reported the highest share (58.1%) and Grant County the lowest (9.8%). EPA's 1993 map puts Clay County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 98% of the county's land moderate radon potential.

West Virginia, the United States and the counties around Clay County, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedian
West Virginia, pooled55 counties, pooled10,06137.5%Not pooled
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled
Morgan Countyhighest in the state24158.1%5.8 pCi/L
Grant Countylowest in the state1649.8%1.1 pCi/L
Roane County, WVborders it2236.4%2.3 pCi/L
Nicholas County, WVborders it1330.8%2.6 pCi/L
Braxton County, WVborders it1225.0%1.3 pCi/L
Kanawha County, WVborders it24720.6%2.2 pCi/L
Calhoun County, WVborders it40.0%2.4 pCi/L
Fayette County, WVborders it200.0%0.8 pCi/L
The nearest West Virginia counties to Clay County with 30 or more tests, 2008 to 2017, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Kanawha County26 mi24720.6%2.2 pCi/L
Putnam County45 mi5223.1%1.5 pCi/L
Raleigh County49 mi4216.7%1.4 pCi/L
Greenbrier County49 mi17652.3%4.5 pCi/L
Wood County57 mi90515.9%1.8 pCi/L
Cabell County63 mi14516.6%2.0 pCi/L
Harrison County68 mi18736.4%2.6 pCi/L
Randolph County68 mi3336.4%2.5 pCi/L
Clay County ten-year laboratory totals, against West Virginia's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestWest Virginia, pooledChange from the row before
2008 to 201710.0%0.1 pCi/L0.1 pCi/L37.5%Level
2007 to 201610.0%0.1 pCi/L0.1 pCi/L37.3%−50.0 points
2006 to 2015250.0%2.4 pCi/L4.6 pCi/L37.7%Level
2005 to 2014250.0%2.4 pCi/L4.6 pCi/L37.3%First on file

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

Clay County, Geology

The ground under Clay County

Predicted

Most of the ground under Clay County is one class on USGS's geologic map: 98.3% of its land is moderate radon potential, with 1.7% low. 98.3% of it lies in the area the map calls Central Allegheny Plateau, to which USGS gives a radon index of 10, in the moderate band (9 to 11).

USGS's geologic areas under Clay County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Central Allegheny PlateauPermian and Pennsylvanian shale, siltstone, sandstone, minor limestone.Moderate1098.3%
Cumberland PlateauPennsylvanian sandstone, siltstone, shale, and coalLow81.7%

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

Clay County beside the ground around it

Across West Virginia 18.7% of the land is rated high; none of Clay County's is. Of the 6 counties that border it, 3 have more moderate-potential ground, Braxton County the most at 100%.

Share of land by USGS radon potential: Clay County, the 6 counties bordering it and West Virginia
AreaEPA zoneLow potentialModerate potentialHigh potential
Clay CountyZone 21.7%98.3%None
Nicholas CountyZone 210.3%89.7%None
Roane CountyZone 2None100%None
Braxton CountyZone 2None100%None
Calhoun CountyZone 2None100%None
Kanawha CountyZone 329.4%70.6%None
Fayette CountyZone 232.5%67.5%None
West Virginia55 counties, pooled by land areaVaries14.0%67.3%18.7%

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

Local help

Clay County, Local resources

Radon testing and mitigation in Clay County

What West Virginia's program says
Phone
304-352-5039
Email
Radon@wv.gov
Licensing of radon professionals
Complete listings of professionals licensed to perform Asbestos, Lead, Radon and Clandestine Drug Laboratory Remediation activities in West Virginia.

What it means

Clay County, Questions

Questions about radon in Clay County

Are radon levels high in Clay County?

Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Clay County, West Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.1 pCi/L. Kanawha County, the one bordering county with a figure over the 2008 to 2017 laboratory totals, reported 20.6% of its tests at or above 4 pCi/L.

Which counties border Clay County?

Clay County borders 6 counties: Nicholas County, Roane County, Braxton County, Calhoun County, Kanawha County and Fayette County.

Products

Clay County, Products

Testing a home in Clay County

No CDC figure names Clay County; the nearest county with one, Kanawha County (26 miles away), reported 20.6% 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. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Clay County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Clay County homes, compared

Explore

Clay County, Bordering counties

Counties bordering Clay County

Calculated by Radon411

Clay County, Cities and towns

Cities and towns in Clay County

Clay County has been losing residents: from 8,009 in 2020 to 7,538 on July 1, 2025, a fall of 5.9% by the Census Bureau's estimates. That works out to 22 people per square mile of land. Clay, its one incorporated place, has 363 residents, 4.8% of the total. Reported testing is thin here: 2 tests over 2006 to 2015, or 0.3 for every 1,000 residents (2025 estimate), where West Virginia as a whole comes to 5.3.

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

Clay, Clay County: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Clay363−8.3%4.8%

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).

Clay County, Homes

Homes in Clay County

Of Clay County's 3,945 homes, 66% are detached houses, against 71% across West Virginia; 31% are mobile homes. Half of its homes were built before 1983, close to West Virginia's 1976: 17% date from before 1960 and 22% from 2000 or later. Owners live in 79% of the occupied homes (West Virginia: 74%), so for most households a test and a fix are their own to order.

Homes in Clay County, West Virginia, 2019 to 2023
HomesClay CountyWest Virginia
Housing units3,945859,653
Detached houses66%71%
In buildings of 5 or more1%8%
Mobile homes31%14%
Built before 196017%33%
Built since 200022%18%
Middle year built19831976
Owner-occupied79%74%

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