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Radon Levels in Gilmer County, West Virginia

EPA puts Gilmer County in Zone 2, its middle radon zone, and only 8 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

How to test this homeFind a certified tester

  • Nearest county

    36.4%

    Harrison County, 36 miles

    Harrison
    36.4%
    WV
    37.5%

    Share at 4+ pCi/L, 187 tests, 2008 to 2017

  • Ground above low

    100.0%

    14.0 pts above WV

    Gilmer
    100.0%
    WV
    86.0%

    Share of land USGS rates moderate or high potential

  • Tests reported

    8

    Too few for a share

    Gilmer
    8
    Needed
    30

    2008 to 2017, 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 Gilmer 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

Gilmer County, At a glance

Gilmer County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Gilmer 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 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

CDC holds 8 reported tests for Gilmer County over the 2008 to 2017 laboratory totals, with a median of 2.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Gilmer County beside the counties around it is how this page reads it.

What these figures count

Only 8 tests were reported to CDC for Gilmer 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

Gilmer County, Compared

Gilmer County radon figures, compared

Calculated by Radon411

CDC's largest figure for Gilmer County rests on 8 tests over the 2008 to 2017 laboratory totals, 1 of them at or above 4 pCi/L, so each test moves its share by 12.5 points and no rank or comparison is drawn from it. Results reached as high as 5.4 pCi/L, with a middle value of 2.1 pCi/L.

The nearest counties with a figure are Harrison County (36 miles away) at 36.4%, Tyler County (37 miles away) at 22.9% and Wood County (41 miles away) at 15.9%. 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 Gilmer County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

West Virginia, the United States and the counties around Gilmer 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
Braxton County, WVborders it1225.0%1.3 pCi/L
Lewis County, WVborders it2313.0%2.0 pCi/L
Ritchie County, WVborders it185.6%1.9 pCi/L
Doddridge County, WVborders it10.0%0.5 pCi/L
Calhoun County, WVborders it40.0%2.4 pCi/L
The nearest West Virginia counties to Gilmer County with 30 or more tests, 2008 to 2017, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Harrison County36 mi18736.4%2.6 pCi/L
Tyler County37 mi3522.9%1.8 pCi/L
Wood County41 mi90515.9%1.8 pCi/L
Wetzel County48 mi5435.2%2.7 pCi/L
Taylor County52 mi3228.1%2.2 pCi/L
Marion County52 mi24429.1%2.6 pCi/L
Randolph County54 mi3336.4%2.5 pCi/L
Kanawha County54 mi24720.6%2.2 pCi/L
Gilmer 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 2017812.5%2.1 pCi/L5.4 pCi/L37.5%Level
2007 to 2016812.5%2.1 pCi/L5.4 pCi/L37.3%Level
2006 to 2015812.5%2.1 pCi/L5.4 pCi/L37.7%Level
2005 to 2014812.5%2.1 pCi/L5.4 pCi/L37.3%First on file

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

Gilmer County, Geology

The ground under Gilmer County

Predicted

USGS's geologic map puts all of Gilmer County's mapped land in one class: moderate radon potential. All 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 Gilmer County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Central Allegheny PlateauPermian and Pennsylvanian shale, siltstone, sandstone, minor limestone.Moderate10100%

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

Gilmer County beside the ground around it

Across West Virginia 18.7% of the land is rated high; none of Gilmer County's is. Of the 5 counties that border it, none has as large a share of moderate-potential ground; Braxton County comes nearest at 100%.

Share of land by USGS radon potential: Gilmer County, the 5 counties bordering it and West Virginia
AreaEPA zoneLow potentialModerate potentialHigh potential
Gilmer CountyZone 2None100%None
Braxton CountyZone 2None100%None
Lewis CountyZone 2None100%None
Calhoun CountyZone 2None100%None
Doddridge CountyZone 2None100%None
Ritchie CountyZone 2None100%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

Gilmer County, Local resources

Radon testing and mitigation in Gilmer 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

Gilmer County, Questions

Questions about radon in Gilmer County

Are radon levels high in Gilmer County?

Over the 2008 to 2017 laboratory totals, 12.5% of the radon tests reported to CDC for Gilmer County, West Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.1 pCi/L. Of the 8 nearest counties with a figure, within 54 miles, the share of tests at or above 4 pCi/L runs from 15.9% to 36.4%.

Which counties border Gilmer County?

Gilmer County borders 5 counties: Braxton County, Lewis County, Calhoun County, Doddridge County and Ritchie County.

Products

Gilmer County, Products

Testing a home in Gilmer County

No CDC figure names Gilmer County; the nearest county with one, Harrison County (36 miles away), reported 36.4% 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 Gilmer County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Gilmer County homes, compared

Explore

Gilmer County, Bordering counties

Counties bordering Gilmer County

Calculated by Radon411

Gilmer County, Cities and towns

Cities and towns in Gilmer County

About 7,085 people live in Gilmer County by the Census Bureau's estimate for July 1, 2025, 308 fewer than in 2020 (−4.2%). That works out to 21 people per square mile of land. No town dominates: Glenville, the largest, has 1,047 residents, 14.8% of the total. Together its 2 incorporated places hold 17.1% of those residents; the other 82.9% live outside any of them. Reported testing is thin here: 8 tests over 2008 to 2017, or 1.1 for every 1,000 residents (2025 estimate), where West Virginia as a whole comes to 5.7.

From Glenville to Sand Fork, CDC publishes no figure by town: each reads Gilmer County's.

The cities and towns in Gilmer County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Glenville1,047−6.1%14.8%
Sand Fork168−6.7%2.4%

2 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).

Gilmer County, Homes

Homes in Gilmer County

Of Gilmer County's 3,118 homes, 69% are detached houses, against 71% across West Virginia; 27% are mobile homes. Half of its homes were built before 1974, close to West Virginia's 1976: 36% date from before 1960 and 13% from 2000 or later. Owners live in 76% of the occupied homes (West Virginia: 74%), so for most households a test and a fix are their own to order.

Homes in Gilmer County, West Virginia, 2019 to 2023
HomesGilmer CountyWest Virginia
Housing units3,118859,653
Detached houses69%71%
In buildings of 5 or more2%8%
Mobile homes27%14%
Built before 196036%33%
Built since 200013%18%
Middle year built19741976
Owner-occupied76%74%

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