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Radon Levels in Allegany County, Maryland

EPA puts Allegany County in Zone 2, its middle radon zone, and 35.7% of its 286 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

    35.7%

    11.8 pts above MD

    Allegany
    35.7%
    Maryland
    23.9%

    286 tests, 2008 to 2017

  • Median result

    2.7pCi/L

    Below action level

    Allegany
    2.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    286

    15th of 19 by tests

    Allegany
    286
    Montgomery
    10,969

    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 Maryland

    5 of 19

    Top quarter

    Allegany
    35.7%
    Washington
    56.0%

    By share, of 19 with 30+ tests

Read a result for Allegany County

Starts at Allegany County's median, 2.7 pCi/L

2.7pCi/L

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

EPA’s reading of 2.7 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. Allegany County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Allegany County, At a glance

Allegany County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Allegany 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: High across 80% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Allegany County, 2008 to 2017, laboratory
Under 2 pCi/L: 40%2 to 4 pCi/L: 24%4 pCi/L and above: 36%

Of 286 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Allegany County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L11640.6%
2 to 4 pCi/L6823.8%
4 pCi/L and above10235.7%
What these figures count

These are the 286 tests reported to CDC for Allegany 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

Allegany County, Compared

Allegany County radon figures, compared

Calculated by Radon411

In Allegany County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (102 of 286) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 0.0 points lower. Across 24 Maryland counties pooled together, 23.9% of tests reached that level, so Allegany County runs 11.8 points above its state.

Of 8 neighbours with a figure, all 8 reported a larger share at or above 4 pCi/L; the spread is 37.4% (Garrett County) to 69.7% (Fulton County, PA). By share, Allegany County is 5th of 19 Maryland counties with 30 or more tests for the same period.

Half the tests came in under 2.7 pCi/L and half over it; the single highest reached 79.0 pCi/L. Below the action level, 116 tests (40.6%) came in under 2 pCi/L, against 56.6% statewide, and 68 tests (23.8%) fell between 2 and 4, against 19.5% statewide.

Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 35.7% share point the same way here. USGS geology rates 80% of the county's land high radon potential. CDC also counts 15 tests taken after mitigation in Allegany County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Allegany County went from 246 tests (2005 to 2014) to 286 (2008 to 2017), the share going from 32.1% to 35.7%.

Allegany County against Maryland, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Allegany County
Allegany County28635.7%2.7 pCi/LThis county
Maryland, pooled24 counties, pooled47,94123.9%Not pooled−11.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooledLevel
Kent Countyhighest in the state5752.6%4.4 pCi/L+16.9 points
Wicomico Countylowest in the state320.0%0.9 pCi/L−35.7 points
Fulton County, PAborders it13269.7%7.9 pCi/L+34.0 points
Morgan County, WVborders it24158.1%5.8 pCi/L+22.4 points
Washington County, MDborders it1,25956.0%5.2 pCi/L+20.3 points
Bedford County, PAborders it59654.4%4.8 pCi/L+18.7 points
Somerset County, PAborders it49845.4%3.5 pCi/L+9.7 points
Mineral County, WVborders it10742.1%2.8 pCi/L+6.4 points
Hampshire County, WVborders it9038.9%2.8 pCi/L+3.2 points
Garrett County, MDborders it18737.4%3.0 pCi/L+1.7 points
Where Allegany County's reported results fell, 2008 to 2017, laboratory, beside Maryland and the United States
ResultAllegany County testsAllegany County shareMaryland shareU.S. shareAgainst Maryland
Under 2 pCi/L11640.6%56.6%39.6%−16.0 points
2 to 4 pCi/L6823.8%19.5%24.7%+4.3 points
4 pCi/L and above10235.7%23.9%35.7%+11.8 points
Allegany County ranked among the 19 Maryland counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Washington County1 of 191,25956.0%5.2 pCi/L
Kent County2 of 195752.6%4.4 pCi/L
Carroll County3 of 193,33441.9%2.8 pCi/L
Garrett County4 of 1918737.4%3.0 pCi/L
Allegany County5 of 1928635.7%2.7 pCi/L
Howard County6 of 194,54930.8%2.0 pCi/L
Calvert County7 of 191,20530.2%2.0 pCi/L
Frederick County8 of 193,93328.1%1.5 pCi/L
Cecil County9 of 191,07124.9%1.9 pCi/L
Charles County10 of 1947724.1%1.8 pCi/L
Harford County11 of 195,28322.6%1.7 pCi/L
Allegany County ten-year laboratory totals, against Maryland's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestMaryland, pooledChange from the row before
2008 to 201728635.7%2.7 pCi/L79.0 pCi/L23.9%+0.3 points
2007 to 201628535.4%2.7 pCi/L79.0 pCi/L24.4%+0.7 points
2006 to 201526834.7%2.7 pCi/L79.0 pCi/L24.9%+2.6 points
2005 to 201424632.1%2.7 pCi/L47.0 pCi/L24.6%First on file

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

Allegany County, Geology

The ground under Allegany County

Predicted

Most of the ground under Allegany County is one class on USGS's geologic map: 80.5% of its land is high radon potential, with 19.5% moderate. The map puts 79.4% of Allegany County in the area it calls Valley and Ridge and 19.5% in Allegheny Plateau, with one smaller area beside them. USGS gives the first a radon index of 13, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).

USGS's geologic areas under Allegany County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Valley and RidgeSilurian and Devonian sandstone, siltstone, shale.High1379.4%
Allegheny PlateauDevonian-Pennsylvanian sandstone, siltstone, shale, limestone, coal.Moderate1119.5%
Northern Appalachian Valley and RidgeSandstone ridges, shale and limestone valleys, mostly DevonianHigh141.1%

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

Allegany County beside the ground around it

Allegany County has more high-potential ground than Maryland as a whole: 80.5% of its land against 36.7%. Of the 8 counties that border it, 6 have more high-potential ground, Fulton County, PA the most at 100%.

Share of land by USGS radon potential: Allegany County, the 8 counties bordering it and Maryland
AreaEPA zoneLow potentialModerate potentialHigh potential
Allegany CountyZone 2None19.5%80.5%
Morgan County, WVZone 1NoneNone100%
Hampshire County, WVZone 1NoneNone100%
Mineral County, WVZone 1None15.8%84.2%
Bedford County, PAZone 1None2.3%97.7%
Fulton County, PAZone 1NoneNone100%
Somerset County, PAZone 2None99.2%0.8%
Garrett CountyZone 2None100%None
Washington CountyZone 14.4%None95.6%
Maryland24 counties, pooled by land areaVaries29.9%27.6%36.7%

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

Local help

Allegany County, Local resources

Radon testing and mitigation in Allegany County

Listed radon businesses with an address in Allegany County:

Listed radon professionals by town: Cumberland

What Maryland's program says
Phone
1-866-703-3266

What it means

Allegany County, Questions

Questions about radon in Allegany County

Are radon levels high in Allegany County?

Over the 2008 to 2017 laboratory totals, 35.7% of the radon tests reported to CDC for Allegany County, Maryland were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.7 pCi/L. Of 19 Maryland counties with 30 or more tests for the same period, 4 reported a higher share; pooled, the state comes to 23.9%.

Which counties border Allegany County?

Allegany County borders 8 counties: Morgan County, WV, Hampshire County, WV, Mineral County, WV, Bedford County, PA, Fulton County, PA, Somerset County, PA, Garrett County, MD and Washington County, MD.

Products

Allegany County, Products

Testing a home in Allegany County

In Allegany County, 35.7% of 286 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 23.9% pooled across Maryland. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Allegany County; a long-term test tells the year-round average.

Test kits and monitors3

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Best radon monitors for Allegany County homes, compared

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Allegany County, Bordering counties

Counties bordering Allegany County

Calculated by Radon411

Allegany County, Cities and towns

Cities and towns in Allegany County

About 66,848 people live in Allegany County by the Census Bureau's estimate for July 1, 2025, 1,119 fewer than in 2020 (−1.6%). That works out to 158 people per square mile of land. Its largest town, Cumberland, has 18,799 residents, 28.1% of the total. Together its 7 incorporated places hold 44.2% of those residents; the other 55.8% live outside any of them. Reported testing is thin here: 286 tests over 2008 to 2017, or 4.3 for every 1,000 residents (2025 estimate), where Maryland as a whole comes to 7.7.

From Cumberland to Luke, CDC publishes no figure by town: each reads Allegany County's.

The cities and towns in Allegany County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Cumberland18,799−1.3%28.1%
Frostburg6,979−0.3%10.4%
Westernport1,759−2.1%2.6%
Lonaconing978−2.0%1.5%
Midland470−2.1%0.7%
Barton454−1.7%0.7%
Luke82−3.5%0.1%

7 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).

Allegany County, Homes

Homes in Allegany County

Of Allegany County's 32,810 homes, 73% are detached houses, against 51% across Maryland; 11% are in buildings of five or more homes. The homes are older than Maryland's as a whole: half were built before 1958 (1979 for Maryland), and 53% date from before 1960. 70% of occupied homes are lived in by their owner (Maryland: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Allegany County, Maryland, 2019 to 2023
HomesAllegany CountyMaryland
Housing units32,8102,545,532
Detached houses73%51%
In buildings of 5 or more11%23%
Mobile homes4%1%
Built before 196053%27%
Built since 20007%20%
Middle year built19581979
Owner-occupied70%67%

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