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Radon Levels in Harrison County, West Virginia

EPA puts Harrison County in Zone 2, its middle radon zone, and 36.4% of its 187 reported radon tests (2008 to 2017, laboratory totals) were 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

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  • Share at 4+ pCi/L

    36.4%

    1.1 pts below WV

    Harrison
    36.4%
    WV
    37.5%

    187 tests, 2008 to 2017

  • Median result

    2.6pCi/L

    Below action level

    Harrison
    2.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    187

    11th of 27 by tests

    Harrison
    187
    Berkeley
    2,888

    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 WV

    11 of 27

    Middle half

    Harrison
    36.4%
    Morgan
    58.1%

    By share, of 27 with 30+ tests

Read a result for Harrison County

Starts at Harrison County's median, 2.6 pCi/L

2.6pCi/L

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

EPA’s reading of 2.6 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. Harrison County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Harrison County, At a glance

Harrison County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Harrison 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 Harrison County, 2008 to 2017, laboratory

Reported results by concentration band, Harrison County, 2008 to 2017, laboratory
Under 2 pCi/L: 37%2 to 4 pCi/L: 27%4 pCi/L and above: 36%

Of 187 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Harrison County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L6836.4%
2 to 4 pCi/L5127.3%
4 pCi/L and above6836.4%
What these figures count

These are the 187 tests reported to CDC for Harrison 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

Harrison County, Compared

Harrison County radon figures, compared

Calculated by Radon411

In Harrison County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (68 of 187) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 0.7 points higher. Across 55 West Virginia counties pooled together, 37.5% of tests reached that level, so Harrison County runs 1.1 points below its state.

Of 3 neighbours with a figure, none reported a larger share at or above 4 pCi/L; the spread is 28.1% (Taylor County) to 35.2% (Wetzel County). By share, Harrison County is 11th of 27 West Virginia counties with 30 or more tests for the same period.

Half the tests came in under 2.6 pCi/L and half over it; the single highest reached 29.5 pCi/L. Below the action level, 68 tests (36.4%) came in under 2 pCi/L, against 37.7% statewide, and 51 tests (27.3%) fell between 2 and 4, against 24.7% statewide.

Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 36.4% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 12 tests taken after mitigation in Harrison County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Harrison County went from 160 tests (2005 to 2014) to 187 (2008 to 2017), the share going from 35.6% to 36.4%.

Harrison County against West Virginia, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Harrison County
Harrison County18736.4%2.6 pCi/LThis county
West Virginia, pooled55 counties, pooled10,06137.5%Not pooled+1.1 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−0.7 points
Morgan Countyhighest in the state24158.1%5.8 pCi/L+21.7 points
Grant Countylowest in the state1649.8%1.1 pCi/L−26.6 points
Wetzel County, WVborders it5435.2%2.7 pCi/L−1.2 points
Marion County, WVborders it24429.1%2.6 pCi/L−7.3 points
Taylor County, WVborders it3228.1%2.2 pCi/L−8.3 points
Barbour County, WVborders it1225.0%2.0 pCi/L−11.4 points
Upshur County, WVborders it2920.7%2.6 pCi/L−15.7 points
Lewis County, WVborders it2313.0%2.0 pCi/L−23.4 points
Doddridge County, WVborders it10.0%0.5 pCi/L−36.4 points
Where Harrison County's reported results fell, 2008 to 2017, laboratory, beside West Virginia and the United States
ResultHarrison County testsHarrison County shareWest Virginia shareU.S. shareAgainst West Virginia
Under 2 pCi/L6836.4%37.7%39.6%−1.3 points
2 to 4 pCi/L5127.3%24.7%24.7%+2.6 points
4 pCi/L and above6836.4%37.5%35.7%−1.1 points
Harrison 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
Brooke County6 of 2715743.9%3.4 pCi/L
Mineral County7 of 2710742.1%2.8 pCi/L
Ohio County8 of 2785340.3%3.2 pCi/L
Hampshire County9 of 279038.9%2.8 pCi/L
Preston County10 of 2717636.9%2.5 pCi/L
Harrison County11 of 2718736.4%2.6 pCi/L
Randolph County11 of 273336.4%2.5 pCi/L
Wetzel County13 of 275435.2%2.7 pCi/L
Mercer County14 of 2710133.7%2.1 pCi/L
Marshall County15 of 2725431.9%2.5 pCi/L
Pendleton County16 of 275530.9%2.5 pCi/L
Harrison 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 201718736.4%2.6 pCi/L29.5 pCi/L37.5%−1.8 points
2007 to 201616538.2%2.9 pCi/L18.0 pCi/L37.3%+3.8 points
2006 to 201518334.4%2.7 pCi/L18.0 pCi/L37.7%−1.2 points
2005 to 201416035.6%2.7 pCi/L18.0 pCi/L37.3%First on file

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

Harrison County, Geology

The ground under Harrison County

Predicted

USGS's geologic map puts all of Harrison 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 Harrison 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.

Harrison County beside the ground around it

Across West Virginia 18.7% of the land is rated high; none of Harrison County's is. Of the 7 counties that border it, none has as large a share of moderate-potential ground; Barbour County comes nearest at 100%.

Share of land by USGS radon potential: Harrison County, the 7 counties bordering it and West Virginia
AreaEPA zoneLow potentialModerate potentialHigh potential
Harrison CountyZone 2None100%None
Marion CountyZone 2None100%None
Taylor CountyZone 2None100%None
Doddridge CountyZone 2None100%None
Wetzel CountyZone 1None100%None
Barbour CountyZone 2None100%None
Lewis CountyZone 2None100%None
Upshur 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

Harrison County, Local resources

Radon testing and mitigation in Harrison County

Listed radon businesses with an address in Harrison County:

Listed radon professionals by town: Clarksburg

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

Harrison County, Questions

Questions about radon in Harrison County

Are radon levels high in Harrison County?

Over the 2008 to 2017 laboratory totals, 36.4% of the radon tests reported to CDC for Harrison County, West Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.6 pCi/L. Of 27 West Virginia counties with 30 or more tests for the same period, 10 reported a higher share; pooled, the state comes to 37.5%.

Which counties border Harrison County?

Harrison County borders 7 counties: Marion County, Taylor County, Doddridge County, Wetzel County, Barbour County, Lewis County and Upshur County.

Products

Harrison County, Products

Testing a home in Harrison County

In Harrison County, 36.4% of 187 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 37.5% pooled across West Virginia. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Harrison County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Harrison County homes, compared

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Harrison County, Bordering counties

Counties bordering Harrison County

Calculated by Radon411

Harrison County, Cities and towns

Cities and towns in Harrison County

About 64,221 people live in Harrison County by the Census Bureau's estimate for July 1, 2025, 1,625 fewer than in 2020 (−2.5%). That works out to 154 people per square mile of land. Its largest town, Clarksburg, has 15,562 residents, 24.2% of the total. Together its 10 incorporated places hold 52.8% of those residents; the other 47.2% live outside any of them. Reported testing is thin here: 187 tests over 2008 to 2017, or 2.9 for every 1,000 residents (2025 estimate), where West Virginia as a whole comes to 5.7.

From Clarksburg to Lost Creek, CDC publishes no figure by town: each reads Harrison County's.

The cities and towns in Harrison County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Clarksburg15,562−4.5%24.2%
Bridgeport9,427+2.1%14.7%
Shinnston2,241−2.9%3.5%
Stonewood1,743−3.8%2.7%
Salem1,570−3.7%2.4%
Nutter Fort1,451−3.3%2.3%
Lumberport648−4.0%1.0%
Anmoore482−3.8%0.8%
West Milford443−3.1%0.7%
Lost Creek363−4.0%0.6%

10 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).

Harrison County, Homes

Homes in Harrison County

Harrison County is a place of houses on their own lots: 75% of its 30,537 homes are detached single-family houses, against 71% across West Virginia. The homes are older than West Virginia's as a whole: half were built before 1963 (1976 for West Virginia), and 47% date from before 1960. 74% of occupied homes are lived in by their owner (West Virginia: 74%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Harrison County, West Virginia, 2019 to 2023
HomesHarrison CountyWest Virginia
Housing units30,537859,653
Detached houses75%71%
In buildings of 5 or more9%8%
Mobile homes7%14%
Built before 196047%33%
Built since 200013%18%
Middle year built19631976
Owner-occupied74%74%

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