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Radon Levels in Washington County, Pennsylvania

Zone 2Moderate predicted potential866 square miles · 9 bordering counties

What this means for you

  • Your area: EPA rates Washington County Zone 2, the middle of its three radon zones. That is a prediction for the whole county, and homes with elevated levels occur in all three zones.
  • Local tests: Of 1,227 radon tests reported to CDC for Washington County (2020), 33.6% were at or above 4 pCi/L, EPA's action level.
  • Your home: The only way to know your home’s level is to test it.

pCi/L (picocuries per liter) is the unit radon is measured in. EPA recommends fixing a home at 4 pCi/L or above, its action level.

In 2020, 33.6% of the radon tests reported to CDC for Washington County, Pennsylvania came back at or above the EPA action level of 4 pCi/L, and the median result was 2.8 pCi/L. EPA's Map of Radon Zones places the county in Zone 2, moderate predicted potential. Radon levels vary from home to home, so only a test measures the level in yours.

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

EPA predicts an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³) across the county as a whole.

This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.

USGS geologic potential: Moderate across 59% of the county's land area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Washington County, 2020

Tests reported
1,227
At or above 4 pCi/L
33.6%
Median result
2.8 pCi/L
Reported results by concentration band, Washington County, 2020
Under 2 pCi/L: 32%2 to 4 pCi/L: 34%4 pCi/L and above: 34%

Of 1,227 pre-mitigation tests reported to CDC, not homes in this area. CDC publishes the share in each band, not a count per band, so the per-band counts in the table are calculated by Radon411 and rounded to add up to the published total.

Reported results by concentration band, Washington County, 2020: data table
Result bandTests Calculated by Radon411Share Measured
Under 2 pCi/L39532.2%
2 to 4 pCi/L42034.2%
4 pCi/L and above41233.6%

Distribution of tested buildings, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.

Measured: CDC tracking data. Figure above: 2020. Measured data period: 2005 to 2020 (every CDC figure on file).

Washington County, In figures

Washington County in figures

What the published data says about Washington County, in words. A zone and a share of tests describe an area, never the level in any one home.

    • Predicted

      Predicted

      EPA places Washington County in Zone 2, moderate predicted potential, as it does 16 other counties of Pennsylvania's 67.

      Of the 9 bordering counties, EPA places Allegheny County, Beaver County, Brooke County, Hancock County, Marshall County, Ohio County and Westmoreland County in Zone 1 and Fayette County and Greene County in Zone 2.

  • Reported tests

    Measured

    CDC has annual figures for Washington County for 7 years, 2014 to 2020. In 2020, 33.6% of 1,227 reported tests were at or above 4 pCi/L.

    Across those years the share ranged from 30.8% (2016) to 37.4% (2015). Few tests in a year can move it a long way.

  • Local record

    Pennsylvania's radon program is the Radon Division, run by Department of Environmental Protection; its contacts are under Local resources.

    The county's largest incorporated places are Washington, Canonsburg and California; the figures here cover them as part of the county.

Washington County, Reported testing

Reported testing over time

Measured
Reported radon test results by year, Washington County, pCi/LLogarithmic scale: each step up the axis multiplies the level, so the median and the single highest result can share one chart. The darker gridline is EPA's action level, 4 pCi/L.
Median reported resultHighest reported result
Reported radon test results by year, Washington County, pCi/L: data table
YearMedian reported resultHighest reported resultShare of tests at or above 4 pCi/L
20142.7 pCi/L70.5 pCi/L34.3%
20153.0 pCi/L316.1 pCi/L37.4%
20162.8 pCi/L96.1 pCi/L30.8%
20172.9 pCi/L91.8 pCi/L35.3%
20182.7 pCi/L373.4 pCi/L31.2%
20192.7 pCi/L125.3 pCi/L31.4%
20202.8 pCi/L71.7 pCi/L33.6%

What these figures count

Every percentage here is a share of radon tests reported to CDC for Washington County in 2020. It is not a share of homes in Washington County, and it is not a random sample: it counts only the tests people chose to run and that were reported.

The shares and the median are calculated from pre-mitigation tests (1,227 for 2020). CDC also reports the number of buildings tested (803), a different count, so the two totals are not interchangeable.

Washington County, State data

Pennsylvania's own radon test data

Measured

What Pennsylvania's own agencies publish about radon tests in Washington 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 Washington County

Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 65 ZIP codes that lie wholly or partly in Washington County, each with the state's own figures for it. Period: Period not stated by DEP.

ZIP codes in Washington County
ZIP codeWhat the state reports
15004Basement: figures not shown
15012Basement: average 4.6 pCi/L, 1,117 tests; First floor: average 3.7 pCi/L, 75 tests
15017Basement: average 3.8 pCi/L, 3,119 tests; First floor: average 2.0 pCi/L, 231 tests
15019Basement: average 5.2 pCi/L, 71 tests; First floor: figures not shown
15021Basement: average 6.4 pCi/L, 490 tests; First floor: average 3.4 pCi/L, 33 tests
15022Basement: average 6.6 pCi/L, 696 tests; First floor: average 5.2 pCi/L, 44 tests
15026Basement: average 9.9 pCi/L, 597 tests; First floor: average 6.8 pCi/L, 30 tests
15033Basement: average 4.4 pCi/L, 135 tests; First floor: figures not shown
15038Basement: figures not shown
15053Basement: figures not shown
15054Basement: figures not shown; First floor: figures not shown
15055Basement: average 2.7 pCi/L, 290 tests; First floor: figures not shown
15057Basement: average 5.6 pCi/L, 2,345 tests; First floor: average 4.2 pCi/L, 107 tests
15060Basement: average 4.4 pCi/L, 69 tests; First floor: figures not shown
15063Basement: average 4.6 pCi/L, 861 tests; First floor: average 4.4 pCi/L, 40 tests
15067Basement: average 4.0 pCi/L, 131 tests; First floor: figures not shown
15078Basement: figures not shown; First floor: figures not shown
15102Basement: average 4.0 pCi/L, 6,724 tests; First floor: average 2.4 pCi/L, 363 tests
15126Basement: average 4.5 pCi/L, 1,411 tests; First floor: average 3.3 pCi/L, 93 tests
15129Basement: average 4.1 pCi/L, 1,661 tests; First floor: average 2.8 pCi/L, 138 tests
15241Basement: average 4.0 pCi/L, 6,779 tests; First floor: average 3.0 pCi/L, 658 tests
15301Basement: average 5.4 pCi/L, 4,564 tests; First floor: average 4.1 pCi/L, 240 tests
15311Basement: average 3.9 pCi/L, 75 tests; First floor: figures not shown
15312Basement: average 5.3 pCi/L, 155 tests; First floor: figures not shown
15313Basement: figures not shown; First floor: figures not shown
15314Basement: average 8.0 pCi/L, 175 tests; First floor: average 4.2 pCi/L, 41 tests
15317Basement: average 4.0 pCi/L, 8,642 tests; First floor: average 3.2 pCi/L, 466 tests
15321Basement: average 4.9 pCi/L, 246 tests; First floor: figures not shown
15322Basement: average 6.1 pCi/L, 69 tests; First floor: figures not shown
15323Basement: average 8.7 pCi/L, 166 tests; First floor: figures not shown
15324Basement: figures not shown; First floor: figures not shown
15329Basement: average 13.7 pCi/L, 43 tests; First floor: figures not shown
15330Basement: average 5.8 pCi/L, 715 tests; First floor: average 9.6 pCi/L, 37 tests
15331Basement: average 8.5 pCi/L, 32 tests; First floor: figures not shown
15332Basement: average 4.7 pCi/L, 773 tests; First floor: average 2.9 pCi/L, 34 tests
15333Basement: average 6.4 pCi/L, 74 tests; First floor: figures not shown
15340Basement: average 7.4 pCi/L, 112 tests; First floor: figures not shown
15342Basement: average 4.2 pCi/L, 643 tests; First floor: average 2.5 pCi/L, 33 tests
15345Basement: average 10.7 pCi/L, 49 tests; First floor: figures not shown
15347Basement: figures not shown; First floor: figures not shown
15348Basement: figures not shown
15350Basement: figures not shown; First floor: figures not shown
15358Basement: figures not shown
15360Basement: average 13.5 pCi/L, 130 tests; First floor: figures not shown
15361Basement: figures not shown
15363Basement: average 5.9 pCi/L, 77 tests; First floor: figures not shown
15365Basement: figures not shown; First floor: figures not shown
15366Basement: figures not shown
15367Basement: average 4.5 pCi/L, 2,490 tests; First floor: average 3.1 pCi/L, 113 tests
15368Basement: figures not shown
15370Basement: average 6.9 pCi/L, 267 tests; First floor: figures not shown
15376Basement: average 6.9 pCi/L, 50 tests; First floor: figures not shown
15377Basement: figures not shown; First floor: figures not shown
15378First floor: figures not shown
15379Basement: figures not shown; First floor: figures not shown
15412Basement: figures not shown
15417Basement: average 5.8 pCi/L, 212 tests; First floor: figures not shown
15419Basement: average 3.6 pCi/L, 123 tests; First floor: figures not shown
15423Basement: average 5.6 pCi/L, 84 tests; First floor: figures not shown
15427Basement: figures not shown; First floor: figures not shown
15429Basement: figures not shown
15432Basement: figures not shown
15434Basement: figures not shown; First floor: figures not shown
15477Basement: figures not shown
15483Basement: figures not shown
  • 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.

Washington County, Comparison

How Washington County compares

Measured

Washington County's own published CDC figures beside those of the counties that border it, for the same period.

Share of reported tests at or above 4 pCi/L

Measured

2020, highest first. Each county’s own published CDC figure.

  1. Beaver CountyPA868 tests42.4%
  2. Westmoreland CountyPA1,588 tests34.9%
  3. Washington CountyThis page1,227 tests33.6%
  4. Allegheny CountyPA8,337 tests30.5%
  5. Greene CountyPA45 tests20.0%
  6. Fayette CountyPA287 tests17.4%

Median reported result

Measured

2020, highest first. Each county’s own published CDC figure.

  1. Beaver CountyPA868 tests3.2 pCi/L
  2. Greene CountyPA45 tests3.2 pCi/L
  3. Washington CountyThis page1,227 tests2.8 pCi/L
  4. Westmoreland CountyPA1,588 tests2.6 pCi/L
  5. Allegheny CountyPA8,337 tests2.5 pCi/L
  6. Fayette CountyPA287 tests1.8 pCi/L

Each figure is that county’s own published CDC figure for 2020, counting radon tests reported to CDC, not homes. Washington County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. No published CDC figure for 2020: Brooke County, WV; Ohio County, WV; Hancock County, WV; Marshall County, WV. Every Pennsylvania county’s own figure is in the Pennsylvania county table.

CDC publishes this figure only for counties here, so there is no state or national number to compare Washington County, Pennsylvania with.

Washington County, Bordering counties

Counties bordering Washington County

Calculated by Radon411

Washington County, Local resources

Local resources in Pennsylvania

Who to ask in Pennsylvania: the state's radon program, test kits and professionals.

Radon Division

Department of Environmental Protection

Pennsylvania’s radon program answers questions about testing, mitigation and the rules where you live.

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...
Visit the program's page(opens in a new tab)

Test kits

The program says: Through an EPA-funded program, hospitals give parents of newborn children a packet of information which includes a coupon for a free radon test kit from the DEP.

Radon professionals

755 professionals are listed in Pennsylvania.

Professionals in Pennsylvania

Washington County, Cities and towns

Cities and towns in Washington County

The radon figures on this page are for Washington County as a whole. They do not differ by city or town.

  • Washington
  • Canonsburg
  • California
  • Donora
  • Charleroi
  • Monongahela
  • Centerville
  • Bentleyville
  • New Eagle
  • McDonald (part)
  • East Washington
  • Burgettstown
  • North Charleroi
  • Houston
  • Speers
  • West Brownsville
  • Midway
  • Ellsworth
  • Deemston
  • Claysville
  • Roscoe
  • Cokeburg
  • Allenport
  • Stockdale
The other 10 places in Washington County
  • Long Branch
  • Beallsville
  • Marianna
  • Dunlevy
  • Finleyville
  • Elco
  • Twilight
  • Coal Center
  • West Middletown
  • Green Hills

34 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county.

Washington County, Questions

Questions about radon in Washington County

Common questions8 questions, answered from the figures above

Are radon levels high in Washington County?

In 2020, 33.6% of the radon tests reported to CDC for Washington County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.8 pCi/L. That is a share of reported tests, not of homes. EPA places Washington County in Zone 2, moderate predicted potential, a predicted average indoor screening level 2 to 4 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.

What a radon level meansRadon in Pennsylvania

How do I get a radon test in Washington County?

EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No certified tester listed on Radon411 names Washington County as a service area yet. The Pennsylvania radon program is the place to ask about certified testers and any test kit offer it runs.

How to test a homeTest kits comparedFree and low-cost kits by statePennsylvania radon program

Who does radon mitigation in Washington County?

No listed mitigator names Washington County as a service area yet; the Pennsylvania directory lists 755 companies. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether Pennsylvania requires one.

How radon mitigation worksWhat mitigation costsMitigators in Pennsylvania

What EPA radon zone is Washington County in?

EPA places Washington County, Pennsylvania in Zone 2, which EPA describes as moderate predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.

Should I test my home in Washington County?

Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.

When is the best time of year to test?

EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.

What does it cost to test?

EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.

Which counties border Washington County?

Washington County borders 9 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.

What these figures mean if you own, buy, sell or rent

The reported-test figures on this page describe Washington County, Pennsylvania in 2020. They describe tests other people carried out in other buildings, and none of them measures yours.

  • If you own your home

    Test the lowest lived-in level; a short-term kit screens in days, a long-term kit reflects the year.

    How to test a home
  • If you are buying

    Ask for past results and any system's post-mitigation test, and test during the sale.

    Buying a house: radon guide
  • If you are selling

    Testing before you list puts the timing in your hands; disclosure rules differ by state.

    Selling a house: radon guide
  • If you rent, or rent out a home

    A tenant can test; a fix is the owner's to make, and duties differ by state.

    Radon in rental homes

How long a test has to run, under what conditions, and what EPA says a result means: the testing standard, in full.

Washington County, Products

Testing and mitigation products

Whatever the figures for Washington County show, only a test tells you about one home.

Washington County / Next steps

What to do next

Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.