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Radon Levels in Grant County, West Virginia

EPA puts Grant County in Zone 1, its highest radon zone, and most reported tests there come back low, though 9.8% of 164 (2008 to 2017, laboratory totals) reached 4 pCi/L. 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

    9.8%

    27.7 pts below WV

    Grant
    9.8%
    WV
    37.5%

    164 tests, 2008 to 2017

  • Median result

    1.1pCi/L

    Below action level

    Grant
    1.1 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    164

    14th of 27 by tests

    Grant
    164
    Berkeley
    2,888

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in WV

    27 of 27

    Lowest quarter

    Grant
    9.8%
    Morgan
    58.1%

    By share, of 27 with 30+ tests

Read a result for Grant County

Starts at Grant County's median, 1.1 pCi/L

1.1pCi/L

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

EPA’s reading of 1.1 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. Grant County's median reported result, 2008 to 2017.

Interpret this reading

The data

Grant County, At a glance

Grant County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Grant County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

USGS geologic potential: High across 75% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Grant County, 2008 to 2017, laboratory
Under 2 pCi/L: 67%2 to 4 pCi/L: 23%4 pCi/L and above: 10%

Of 164 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Grant County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L11067.1%
2 to 4 pCi/L3823.2%
4 pCi/L and above169.8%
What these figures count

These are the 164 tests reported to CDC for Grant 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

Grant County, Compared

Grant County radon figures, compared

Calculated by Radon411

Grant County reports fewer high tests than West Virginia overall. 9.8% of its 164 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 27.7 points below the 37.5% pooled from 55 West Virginia counties.

Ordered from highest share down, it comes 27th of 27 West Virginia counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Grant County sits 25.9 points below it.

Next door, the shares run from 22.6% in Hardy County to 42.1% in Mineral County. The reported tests do not follow EPA's Zone 1 label for Grant County (predicted average above 4 pCi/L): 9.8% of them reached 4 pCi/L, fewer than that label suggests.

Half the tests came in under 1.1 pCi/L and half over it; the single highest reached 30.2 pCi/L. The rest split 67.1% under 2 pCi/L and 23.2% from 2 to 4 (West Virginia: 37.7% and 24.7%).

CDC's ten-year totals for Grant County went from 182 tests (2005 to 2014) to 164 (2008 to 2017), the share going from 7.1% to 9.8%.

Grant County against West Virginia, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Grant County
Grant County1649.8%1.1 pCi/LThis county
West Virginia, pooled55 counties, pooled10,06137.5%Not pooled+27.7 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+25.9 points
Morgan Countyhighest in the state24158.1%5.8 pCi/L+48.3 points
Wood Countylowest in the state90515.9%1.8 pCi/L+6.1 points
Mineral County, WVborders it10742.1%2.8 pCi/L+32.3 points
Hampshire County, WVborders it9038.9%2.8 pCi/L+29.1 points
Garrett County, MDborders it18737.4%3.0 pCi/L+27.6 points
Preston County, WVborders it17636.9%2.5 pCi/L+27.1 points
Randolph County, WVborders it3336.4%2.5 pCi/L+26.6 points
Pendleton County, WVborders it5530.9%2.5 pCi/L+21.1 points
Tucker County, WVborders it1827.8%1.8 pCi/L+18.0 points
Hardy County, WVborders it5322.6%1.6 pCi/L+12.8 points
Where Grant County's reported results fell, 2008 to 2017, laboratory, beside West Virginia and the United States
ResultGrant County testsGrant County shareWest Virginia shareU.S. shareAgainst West Virginia
Under 2 pCi/L11067.1%37.7%39.6%+29.4 points
2 to 4 pCi/L3823.2%24.7%24.7%−1.5 points
4 pCi/L and above169.8%37.5%35.7%−27.7 points
Grant County ranked among the 27 West 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
Marion County17 of 2724429.1%2.6 pCi/L
Taylor County18 of 273228.1%2.2 pCi/L
Putnam County19 of 275223.1%1.5 pCi/L
Tyler County20 of 273522.9%1.8 pCi/L
Hardy County21 of 275322.6%1.6 pCi/L
Kanawha County22 of 2724720.6%2.2 pCi/L
Monongalia County23 of 271,17619.0%1.9 pCi/L
Raleigh County24 of 274216.7%1.4 pCi/L
Cabell County25 of 2714516.6%2.0 pCi/L
Wood County26 of 2790515.9%1.8 pCi/L
Grant County27 of 271649.8%1.1 pCi/L
Grant 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 20171649.8%1.1 pCi/L30.2 pCi/L37.5%+2.9 points
2007 to 20161606.9%1.1 pCi/L11.0 pCi/L37.3%−0.1 points
2006 to 20151717.0%1.1 pCi/L12.2 pCi/L37.7%−0.1 points
2005 to 20141827.1%1.2 pCi/L12.2 pCi/L37.3%First on file

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

Grant County, Geology

The ground under Grant County

Predicted

Most of the ground under Grant County is one class on USGS's geologic map: 75.5% of its land is high radon potential, with 24.5% moderate. The map puts 75.5% of Grant County in the area it calls Northern Appalachian Valley and Ridge and 24.4% in Eastern Allegheny Plateau and Mtns. USGS gives the first a radon index of 14, in the high band (12 to 17), and the second 10, in the moderate band (9 to 11).

USGS's geologic areas under Grant County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Northern Appalachian Valley and RidgeSandstone ridges, shale and limestone valleys, mostly DevonianHigh1475.5%
Eastern Allegheny Plateau and MtnsDevonian-Pennsylvanian shale, siltstone, sandstone, minor limestone and coalModerate1024.4%

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

Grant County beside the ground around it

Grant County has more high-potential ground than West Virginia as a whole: 75.5% of its land against 18.7%. Of the 8 counties that border it, 4 have more high-potential ground, Hampshire County the most at 100%.

Share of land by USGS radon potential: Grant County, the 8 counties bordering it and West Virginia
AreaEPA zoneLow potentialModerate potentialHigh potential
Grant CountyZone 1None24.5%75.5%
Hardy CountyZone 1NoneNone100%
Tucker CountyZone 2None99.8%0.2%
Pendleton CountyZone 1None1.9%98.1%
Garrett County, MDZone 2None100%None
Mineral CountyZone 1None15.8%84.2%
Hampshire CountyZone 1NoneNone100%
Preston CountyZone 1None100%None
Randolph CountyZone 2None97.1%2.9%
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

Grant County, Local resources

Radon testing and mitigation in Grant 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

Grant County, Questions

Questions about radon in Grant County

Are radon levels high in Grant County?

Over the 2008 to 2017 laboratory totals, 9.8% of the radon tests reported to CDC for Grant County, West Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.1 pCi/L. Of 27 West Virginia counties with 30 or more tests for the same period, 26 reported a higher share; pooled, the state comes to 37.5%.

Which counties border Grant County?

Grant County borders 8 counties: Hardy County, WV, Tucker County, WV, Pendleton County, WV, Garrett County, MD, Mineral County, WV, Hampshire County, WV, Preston County, WV and Randolph County, WV.

Products

Grant County, Products

Testing a home in Grant County

In Grant County, 9.8% of 164 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 37.5% pooled across West Virginia. In Zone 1 the year-round level in Grant County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.

Test kits and monitors3

See every kit and monitor

Grant County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Grant County

Explore

Grant County, Bordering counties

Counties bordering Grant County

Calculated by Radon411

Grant County, Cities and towns

Cities and towns in Grant County

Grant County's population has barely moved since 2020: 11,041 residents on July 1, 2025 against 10,993 then, by the Census Bureau's estimates. That works out to 23 people per square mile of land. Its largest town, Petersburg, has 2,282 residents, 20.7% of the total. Together its 2 incorporated places hold 22.6% of those residents; the other 77.4% live outside any of them. Testing is reported here more often than across the state: CDC's 164 reported tests for 2008 to 2017 come to 14.9 for every 1,000 residents (2025 estimate), against 5.7 for West Virginia.

From Petersburg to Bayard, CDC publishes no figure by town: each reads Grant County's.

The cities and towns in Grant County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Petersburg2,282−0.7%20.7%
Bayard209−2.3%1.9%

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).

Grant County, Homes

Homes in Grant County

Grant County is a place of houses on their own lots: 78% of its 5,660 homes are detached single-family houses, against 71% across West Virginia. Half of its homes were built before 1980, close to West Virginia's 1976: 24% date from before 1960 and 19% from 2000 or later. Owners live in 81% of the occupied homes (West Virginia: 74%), so for most households a test and a fix are their own to order.

Homes in Grant County, West Virginia, 2019 to 2023
HomesGrant CountyWest Virginia
Housing units5,660859,653
Detached houses78%71%
In buildings of 5 or more4%8%
Mobile homes14%14%
Built before 196024%33%
Built since 200019%18%
Middle year built19801976
Owner-occupied81%74%

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