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Radon Levels in Westmoreland County, Pennsylvania

EPA puts Westmoreland County in Zone 1, its highest radon zone, and 34.9% of its 1,588 reported radon tests (2020) 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    34.9%

    4.6 pts above PA

    Westmoreland
    34.9%
    PA
    30.3%

    1,588 tests, 2020

  • Median result

    2.6pCi/L

    Below action level

    Westmoreland
    2.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2020

  • Tests reported

    1,588

    15th of 63 by tests

    Westmoreland
    1,588
    Montgomery
    10,508

    Reported to CDC before any fix, 2020

  • 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 PA

    40 of 63

    Middle half

    Westmoreland
    34.9%
    Perry
    57.7%

    By share, of 63 with 30+ tests

Read a result for Westmoreland County

Starts at Westmoreland 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. Westmoreland County's median reported result, 2020.

Interpret this readingWhat a fix costs

The data

Westmoreland County, At a glance

Westmoreland County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Westmoreland 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 65% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Westmoreland County, 2020

Share of reported tests at or above 4 pCi/L, by year, Westmoreland County
Share of reported tests at or above 4 pCi/L, by year, Westmoreland County
YearShare of reported tests at or above 4 pCi/L
201441.2%
201541.6%
201638.0%
201739.1%
201830.4%
201934.7%
202034.9%

2020: 34.9%. Across these years the share ran from 30.4% to 41.6%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 1,588 tests reported to CDC for Westmoreland County over 2020, 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: 2020. Measured data period: 2005 to 2020 (every CDC figure on file).

How to read these figures

Westmoreland County, Compared

Westmoreland County radon figures, compared

Calculated by Radon411

In Westmoreland County, about 3 in 10 reported tests in 2020 (554 of 1,588) were at or above EPA's action level. Against the national pool of 25.5%, the gap is 9.4 points higher. Across 67 Pennsylvania counties pooled together, 30.3% of tests reached that level, so Westmoreland County runs 4.6 points above its state.

Of 8 neighbours with a figure, 5 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 17.4% (Fayette County) to 47.6% (Armstrong County). By share, Westmoreland County is 40th of 63 Pennsylvania counties with 30 or more tests for the same period.

Year by year, 2014 opened at 41.2% and 2020 closed at 34.9% (down 6.3 points), with 2015 the high at 41.6%. Half the tests came in under 2.6 pCi/L and half over it; the single highest reached 212.0 pCi/L. Below the action level, 597 tests (37.6%) came in under 2 pCi/L, against 44.3% statewide, and 437 tests (27.5%) fell between 2 and 4, against 25.4% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 34.9% share point the same way here. USGS geology rates 65% of the county's land high radon potential.

The busiest year on file was 2019, with 1,786 tests reported; the quietest, 2017, had 1,372.

Share of reported tests at or above 4 pCi/L by year, Westmoreland County against Pennsylvania2014 to 2020, years with 30 or more tests: Westmoreland County 41.2% to 34.9%, the state's pooled share 30.3% in 2020.
Westmoreland CountyPennsylvania, pooled
Share of reported tests at or above 4 pCi/L by year, Westmoreland County against Pennsylvania: data table
YearTestsWestmoreland County, at or above 4 pCi/LPennsylvania, pooled
20141,37741.2%36.1%
20151,70441.6%37.8%
20161,70338.0%34.4%
20171,37239.1%35.1%
20181,75830.4%30.5%
20191,78634.7%31.4%
20201,58834.9%30.3%
Westmoreland County against Pennsylvania, the United States and nearby counties, 2020
AreaTestsAt or above 4 pCi/LMedianDifference from Westmoreland County
Westmoreland County1,58834.9%2.6 pCi/LThis county
Pennsylvania, pooled67 counties, pooled93,66930.3%Not pooled−4.6 points
United States, pooled915 counties, pooled405,35525.5%Not pooled−9.4 points
Perry Countyhighest in the state18957.7%4.9 pCi/L+22.8 points
Philadelphia Countylowest in the state8,44210.6%1.7 pCi/L−24.3 points
Armstrong County, PAborders it18747.6%3.7 pCi/L+12.7 points
Cambria County, PAborders it32944.7%3.3 pCi/L+9.8 points
Indiana County, PAborders it22844.3%3.6 pCi/L+9.4 points
Somerset County, PAborders it12643.7%3.7 pCi/L+8.8 points
Butler County, PAborders it1,49242.3%3.3 pCi/L+7.4 points
Washington County, PAborders it1,22733.6%2.8 pCi/L−1.3 points
Allegheny County, PAborders it8,33730.5%2.5 pCi/L−4.4 points
Fayette County, PAborders it28717.4%1.8 pCi/L−17.5 points
Where Westmoreland County's reported results fell, 2020, beside Pennsylvania and the United States
ResultWestmoreland County testsWestmoreland County sharePennsylvania shareU.S. shareAgainst Pennsylvania
Under 2 pCi/L59737.6%44.3%51.6%−6.7 points
2 to 4 pCi/L43727.5%25.4%22.9%+2.1 points
4 pCi/L and above55434.9%30.3%25.5%+4.6 points
Westmoreland County ranked among the 63 Pennsylvania counties with 30 or more tests, by share at or above 4 pCi/L, 2020
CountyRankTestsAt or above 4 pCi/LMedian
Warren County35 of 6311938.7%2.8 pCi/L
Jefferson County36 of 6325438.6%2.6 pCi/L
Susquehanna County37 of 6311637.9%3.0 pCi/L
Dauphin County38 of 632,98636.9%2.0 pCi/L
Lawrence County39 of 6328636.0%2.7 pCi/L
Westmoreland County40 of 631,58834.9%2.6 pCi/L
Columbia County41 of 6340934.7%2.0 pCi/L
Venango County42 of 6317934.1%3.0 pCi/L
Washington County43 of 631,22733.6%2.8 pCi/L
Clarion County44 of 6310731.8%2.9 pCi/L
Mercer County45 of 6331831.4%2.5 pCi/L
Westmoreland County radon tests by year, against Pennsylvania's pooled share
YearTestsAt or above 4 pCi/LMedianHighestPennsylvania, pooledChange from the row before
20201,58834.9%2.6 pCi/L212.0 pCi/L30.3%+0.2 points
20191,78634.7%2.8 pCi/L129.0 pCi/L31.4%+4.3 points
20181,75830.4%2.5 pCi/L128.1 pCi/L30.5%−8.7 points
20171,37239.1%3.0 pCi/L157.5 pCi/L35.1%+1.1 points
20161,70338.0%3.0 pCi/L202.0 pCi/L34.4%−3.6 points
20151,70441.6%3.2 pCi/L173.6 pCi/L37.8%+0.4 points
20141,37741.2%3.2 pCi/L304.0 pCi/L36.1%First on file

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

Westmoreland County, State data

Pennsylvania's own radon test data

Measured

What Pennsylvania's own agencies publish about radon tests in Westmoreland County, with their period. These are not CDC's figures and are never added to them.

MeasuredState figures, not CDC's

What Pennsylvania DEP reports for the ZIP codes in Westmoreland County

Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 88 ZIP codes that lie wholly or partly in Westmoreland County, each with the state's own figures for it. Period: Period not stated by DEP.

ZIP codes in Westmoreland County
ZIP codeWhat the state reports
15012Basement: average 4.6 pCi/L, 1,117 tests; First floor: average 3.7 pCi/L, 75 tests
15062Basement: average 4.8 pCi/L, 403 tests; First floor: figures not shown
15068Basement: average 5.7 pCi/L, 3,496 tests; First floor: average 5.0 pCi/L, 187 tests
15083Basement: average 4.7 pCi/L, 50 tests; First floor: figures not shown
15085Basement: average 4.6 pCi/L, 1,310 tests; First floor: average 3.2 pCi/L, 60 tests
15087Basement: figures not shown
15089Basement: average 5.9 pCi/L, 372 tests; First floor: average 4.5 pCi/L, 57 tests
15131Basement: average 4.4 pCi/L, 1,075 tests; First floor: figures not shown
15137Basement: average 4.6 pCi/L, 782 tests; First floor: average 1.8 pCi/L, 55 tests
15146Basement: average 5.5 pCi/L, 5,878 tests; First floor: average 3.7 pCi/L, 290 tests
15448Basement: figures not shown; First floor: figures not shown
15479Basement: average 5.8 pCi/L, 68 tests; First floor: figures not shown
15501Basement: average 8.6 pCi/L, 914 tests; First floor: average 3.2 pCi/L, 92 tests
15531Basement: average 5.0 pCi/L, 136 tests; First floor: figures not shown
15601Basement: average 5.9 pCi/L, 9,788 tests; First floor: average 4.1 pCi/L, 576 tests
15610Basement: average 7.7 pCi/L, 190 tests; First floor: figures not shown
15611Basement: figures not shown; First floor: figures not shown
15612Basement: figures not shown; First floor: figures not shown
15613Basement: average 10.2 pCi/L, 1,442 tests; First floor: average 6.1 pCi/L, 99 tests
15615Basement: figures not shown; First floor: figures not shown
15616Basement: figures not shown; First floor: figures not shown
15617Basement: figures not shown; First floor: figures not shown
15618Basement: average 4.7 pCi/L, 99 tests; First floor: figures not shown
15619Basement: figures not shown; First floor: figures not shown
15620Basement: figures not shown; First floor: figures not shown
15622Basement: average 11.6 pCi/L, 191 tests; First floor: average 8.9 pCi/L, 89 tests
15623Basement: average 7.9 pCi/L, 67 tests; First floor: figures not shown
15624Basement: figures not shown
15625Basement: figures not shown
15626Basement: average 11.4 pCi/L, 944 tests; First floor: figures not shown
15627Basement: average 5.1 pCi/L, 410 tests; First floor: average 5.1 pCi/L, 60 tests
15628Basement: figures not shown; First floor: figures not shown
15629Basement: figures not shown
15632Basement: average 6.6 pCi/L, 1,839 tests; First floor: average 3.1 pCi/L, 95 tests
15633Basement: figures not shown
15634Basement: average 4.8 pCi/L, 31 tests; First floor: figures not shown
15635Basement: figures not shown
15636Basement: average 6.0 pCi/L, 855 tests; First floor: average 4.1 pCi/L, 31 tests
15637Basement: average 7.6 pCi/L, 134 tests; First floor: figures not shown
15638Basement: figures not shown; First floor: figures not shown
15639Basement: average 5.9 pCi/L, 152 tests; First floor: figures not shown
15640Basement: figures not shown
15641Basement: figures not shown; First floor: figures not shown
15642Basement: average 5.1 pCi/L, 4,782 tests; First floor: average 4.1 pCi/L, 170 tests
15644Basement: average 6.2 pCi/L, 2,198 tests; First floor: average 5.2 pCi/L, 90 tests
15646Basement: figures not shown
15647Basement: figures not shown; First floor: figures not shown
15650Basement: average 5.4 pCi/L, 2,600 tests; First floor: average 3.8 pCi/L, 210 tests
15655Basement: average 3.8 pCi/L, 56 tests; First floor: figures not shown
15656Basement: average 6.1 pCi/L, 847 tests; First floor: average 9.2 pCi/L, 60 tests
15658Basement: average 8.2 pCi/L, 1,194 tests; First floor: average 5.4 pCi/L, 104 tests
15660Basement: figures not shown; First floor: figures not shown
15661Basement: average 4.1 pCi/L, 49 tests; First floor: figures not shown
15662Basement: figures not shown
15663Basement: figures not shown; First floor: figures not shown
15665Basement: average 5.4 pCi/L, 231 tests; First floor: figures not shown
15666Basement: average 4.4 pCi/L, 677 tests; First floor: average 2.1 pCi/L, 149 tests
15668Basement: average 6.8 pCi/L, 4,314 tests; First floor: average 5.0 pCi/L, 215 tests
15670Basement: average 8.1 pCi/L, 189 tests; First floor: figures not shown
15671Basement: average 7.7 pCi/L, 35 tests; First floor: figures not shown
15672Basement: average 5.4 pCi/L, 283 tests; First floor: average 3.0 pCi/L, 43 tests
15674Basement: figures not shown; First floor: figures not shown
15675Basement: average 3.7 pCi/L, 67 tests; First floor: figures not shown
15676Basement: average 6.6 pCi/L, 36 tests; First floor: figures not shown
15677Basement: average 6.0 pCi/L, 60 tests; First floor: figures not shown
15678Basement: average 10.5 pCi/L, 35 tests; First floor: figures not shown
15679Basement: average 6.2 pCi/L, 86 tests; First floor: figures not shown
15680Basement: figures not shown
15681Basement: average 9.0 pCi/L, 241 tests; First floor: figures not shown
15683Basement: average 4.2 pCi/L, 384 tests; First floor: average 4.5 pCi/L, 43 tests
15684Basement: figures not shown; First floor: figures not shown
15687Basement: average 12.4 pCi/L, 97 tests; First floor: figures not shown
15688Basement: figures not shown
15689Basement: figures not shown; First floor: figures not shown
15690Basement: average 5.0 pCi/L, 410 tests; First floor: figures not shown
15691Basement: figures not shown; First floor: figures not shown
15692Basement: average 4.3 pCi/L, 100 tests; First floor: figures not shown
15693Basement: figures not shown; First floor: figures not shown
15695Basement: figures not shown; First floor: figures not shown
15696Basement: figures not shown; First floor: figures not shown
15697Basement: average 4.0 pCi/L, 279 tests; First floor: figures not shown
15698Basement: figures not shown; First floor: figures not shown
15717Basement: average 5.5 pCi/L, 731 tests; First floor: average 6.1 pCi/L, 57 tests
15779Basement: figures not shown; First floor: figures not shown
15923Basement: average 7.1 pCi/L, 48 tests; First floor: figures not shown
15944Basement: average 7.3 pCi/L, 136 tests; First floor: figures not shown
15954Basement: average 10.4 pCi/L, 85 tests; First floor: figures not shown
16229Basement: average 10.9 pCi/L, 458 tests; First floor: average 10.5 pCi/L, 36 tests
  • DEP's report gives the number of tests, the highest result and the average result for each floor tested; it states no period.
  • DEP says the smartest thing to do is to test your home for radon, no matter where you live.
  • A ZIP code that crosses the county line is listed whole; its figures cover all of it.

Measured: Pennsylvania DEP data, Period not stated by DEP.

Westmoreland County, Geology

The ground under Westmoreland County

Predicted

USGS's geologic map splits Westmoreland County: 65.4% of its land is high radon potential and 34.6% moderate. The map puts 65.4% of Westmoreland County in the area it calls Pennsylvanian Rocks of the Pittsburgh Low Plateau and 34.6% in Allegheny Mountain Section. USGS gives the first a radon index of 14, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).

USGS's geologic areas under Westmoreland County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Pennsylvanian Rocks of the Pittsburgh Low PlateauPennsylvanian marine shale, siltstone, sandstone, limestone, and coal.High1465.4%
Allegheny Mountain SectionPennsylvanian sandstone, siltstone, shale, limestone, coal.Moderate1134.6%

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

Westmoreland County beside the ground around it

On high-potential ground Westmoreland County is close to Pennsylvania as a whole: 65.4% of its land against 70.4%. Of the 8 counties that border it, 4 have more high-potential ground, Allegheny County the most at 100%.

Share of land by USGS radon potential: Westmoreland County, the 8 counties bordering it and Pennsylvania
AreaEPA zoneLow potentialModerate potentialHigh potential
Westmoreland CountyZone 1None34.6%65.4%
Indiana CountyZone 1None23.2%76.8%
Fayette CountyZone 2None55.8%44.2%
Somerset CountyZone 2None99.2%0.8%
Allegheny CountyZone 1NoneNone100%
Armstrong CountyZone 1NoneNone100%
Cambria CountyZone 2None97.6%2.4%
Washington CountyZone 2None58.8%41.2%
Butler CountyZone 1None2.0%98.0%
Pennsylvania67 counties, pooled by land areaVaries0.7%28.9%70.4%

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

Local help

Westmoreland County, Local resources

Radon testing and mitigation in Westmoreland County

Listed radon businesses with an address in Westmoreland County:

Listed radon professionals by town: New Kensington, Irwin, Derry

What Pennsylvania's program says
Phone
800-237-2366
Licensing of radon professionals
The Radon Certification Act requires DEP to establish by regulation, a certification program for persons conducting radon gas and radon progeny testing, laboratory analysis and mitigation of radon contamination in buildings.

What it means

Westmoreland County, Questions

Questions about radon in Westmoreland County

Are radon levels high in Westmoreland County?

In 2020, 34.9% of the radon tests reported to CDC for Westmoreland County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.6 pCi/L. Of 63 Pennsylvania counties with 30 or more tests for the same period, 39 reported a higher share; pooled, the state comes to 30.3%.

Which counties border Westmoreland County?

Westmoreland County borders 8 counties: Indiana County, Fayette County, Somerset County, Allegheny County, Armstrong County, Cambria County, Washington County and Butler County.

Products

Westmoreland County, Products

Testing a home in Westmoreland County

In Westmoreland County, 34.9% of 1,588 tests reported to CDC in 2020 reached 4 pCi/L, against 30.3% pooled across Pennsylvania. In Zone 1 the year-round level in Westmoreland 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

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

Explore

Westmoreland County, Bordering counties

Counties bordering Westmoreland County

Calculated by Radon411

Westmoreland County, Cities and towns

Cities and towns in Westmoreland County

About 349,324 people live in Westmoreland County by the Census Bureau's estimate for July 1, 2025, 4,946 fewer than in 2020 (−1.4%). That works out to 340 people per square mile of land. No town dominates: Murrysville, the largest, has 20,636 residents, 5.9% of the total. Reported testing is thin here: 1,588 tests over 2020, or 4.5 for every 1,000 residents (2025 estimate), where Pennsylvania as a whole comes to 7.2.

From Murrysville to Donegal, CDC publishes no figure by town: each reads Westmoreland County's.

The 12 largest cities and towns in Westmoreland County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Murrysville20,636−1.6%5.9%
Greensburg14,462−3.0%4.1%
New Kensington11,759−3.1%3.4%
Lower Burrell11,470−2.4%3.3%
Jeannette8,489−3.1%2.4%
Latrobe7,826−2.8%2.2%
Monessen6,657−3.0%1.9%
Vandergrift4,903−3.1%1.4%
Arnold4,619−3.1%1.3%
Scottdale4,271−3.0%1.2%
Mount Pleasant4,108−3.1%1.2%
Irwin3,759−3.0%1.1%
  • Manor
  • Trafford (part)
  • Youngwood
  • Delmont
  • West Newton
  • Derry
  • New Stanton
  • Southwest Greensburg
  • South Greensburg
  • North Belle Vernon
  • Ligonier
  • West Leechburg
  • Avonmore
  • Export
  • North Irwin
  • Oklahoma
  • New Florence
  • Penn
  • East Vandergrift
  • Sutersville
  • Hyde Park
  • New Alexandria
  • Bolivar
  • Seward
The other 8 places in Westmoreland County
  • Madison
  • Smithton
  • Hunker
  • Arona
  • Youngstown
  • Laurel Mountain
  • Adamsburg
  • Donegal

44 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).

Westmoreland County, Homes

Homes in Westmoreland County

Westmoreland County is a place of houses on their own lots: 77% of its 168,406 homes are detached single-family houses, against 57% across Pennsylvania. Half of its homes were built before 1964, close to Pennsylvania's 1965: 45% date from before 1960 and 11% from 2000 or later. Owners live in 78% of the occupied homes (Pennsylvania: 69%), so for most households a test and a fix are their own to order.

Homes in Westmoreland County, Pennsylvania, 2019 to 2023
HomesWestmoreland CountyPennsylvania
Housing units168,4065,779,663
Detached houses77%57%
In buildings of 5 or more7%13%
Mobile homes5%4%
Built before 196045%45%
Built since 200011%14%
Middle year built19641965
Owner-occupied78%69%

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