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Radon Levels in Delaware County, Pennsylvania

EPA puts Delaware County in Zone 1, its highest radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

Predicted
Zone 1Highest predicted potential
Measured
14.7%of 6,041 tests reported to CDC (2020) were at or above 4 pCi/L
Your home
Test to knowNo area figure here is a reading of your home.
How to test this homeFind a certified tester

The data

Delaware County, At a glance

Delaware County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

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.

What EPA predicts hereScreening level, geology

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

USGS geologic potential: High across 77% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Delaware County, 2020

Tests reported
6,041
At or above 4 pCi/L
14.7%
Median result
1.8 pCi/L
Reported results by concentration band, Delaware County, 2020
Under 2 pCi/L: 53%2 to 4 pCi/L: 32%4 pCi/L and above: 15%

Of 6,041 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Delaware County, 2020: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L3,22253.3%
2 to 4 pCi/L1,93031.9%
4 pCi/L and above88914.7%

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

What these figures count

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

The figures at the top are for 2020: a percentage there is a share of radon tests reported to CDC for Delaware County in 2020, and a percentage in a view below is a share of the tests reported for the year or period it names. It is not a share of homes in Delaware County, and it is not a random sample: it counts only the tests people chose to run and that were reported.

CDC works out the shares and the median over pre-mitigation tests, counting a test not marked as before or after mitigation as one of them (6,041 for 2020). The median is the middle result of those tests, not of buildings. CDC also reports the number of buildings tested (3,894), a different count, so the two totals are not interchangeable.

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

Each figure is that county’s own published CDC figure for 2020, counting radon tests reported to CDC, not homes. Delaware 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: New Castle County, DE. Every Pennsylvania county’s own figure is in the Pennsylvania county table.

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

Delaware County, State data

Pennsylvania's own radon test data

Measured

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

Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 45 ZIP codes that lie wholly or partly in Delaware County, each with the state's own figures for it. Period: Period not stated by DEP.

ZIP codes in Delaware County
ZIP codeWhat the state reports
19003Basement: average 2.5 pCi/L, 3,078 tests; First floor: average 1.3 pCi/L, 723 tests
19008Basement: average 3.4 pCi/L, 3,658 tests; First floor: average 2.0 pCi/L, 714 tests
19010Basement: average 3.2 pCi/L, 4,858 tests; First floor: average 1.7 pCi/L, 1,151 tests
19013Basement: average 1.8 pCi/L, 814 tests; First floor: average 0.9 pCi/L, 165 tests
19014Basement: average 2.3 pCi/L, 2,998 tests; First floor: average 1.2 pCi/L, 383 tests
19015Basement: average 1.6 pCi/L, 1,460 tests; First floor: average 1.0 pCi/L, 233 tests
19017Basement: average 2.4 pCi/L, 57 tests; First floor: figures not shown
19018Basement: average 2.3 pCi/L, 2,340 tests; First floor: average 1.3 pCi/L, 418 tests
19022Basement: average 1.3 pCi/L, 160 tests; First floor: figures not shown
19023Basement: average 1.5 pCi/L, 967 tests; First floor: average 1.0 pCi/L, 197 tests
19026Basement: average 2.7 pCi/L, 5,518 tests; First floor: average 1.7 pCi/L, 1,002 tests
19029Basement: average 1.4 pCi/L, 171 tests; First floor: average 0.9 pCi/L, 34 tests
19032Basement: average 1.2 pCi/L, 646 tests; First floor: average 1.0 pCi/L, 49 tests
19033Basement: average 2.1 pCi/L, 799 tests; First floor: average 1.1 pCi/L, 113 tests
19036Basement: average 1.6 pCi/L, 1,200 tests; First floor: average 1.2 pCi/L, 168 tests
19041Basement: average 3.9 pCi/L, 1,595 tests; First floor: average 1.9 pCi/L, 348 tests
19043Basement: average 1.4 pCi/L, 212 tests; First floor: average 1.0 pCi/L, 48 tests
19050Basement: average 2.8 pCi/L, 3,542 tests; First floor: average 1.5 pCi/L, 835 tests
19052Basement: figures not shown; First floor: figures not shown
19060Basement: average 2.6 pCi/L, 871 tests; First floor: figures not shown
19061Basement: average 2.5 pCi/L, 2,384 tests; First floor: average 1.4 pCi/L, 375 tests
19063Basement: average 4.1 pCi/L, 8,556 tests; First floor: average 2.5 pCi/L, 1,260 tests
19064Basement: average 3.7 pCi/L, 5,237 tests; First floor: average 2.1 pCi/L, 821 tests
19070Basement: average 2.9 pCi/L, 839 tests; First floor: average 2.2 pCi/L, 115 tests
19073Basement: average 3.0 pCi/L, 4,853 tests; First floor: average 1.8 pCi/L, 871 tests
19074Basement: average 1.8 pCi/L, 438 tests; First floor: average 1.2 pCi/L, 83 tests
19076Basement: average 2.0 pCi/L, 479 tests; First floor: average 0.9 pCi/L, 94 tests
19078Basement: average 2.1 pCi/L, 1,205 tests; First floor: average 1.1 pCi/L, 184 tests
19079Basement: average 1.9 pCi/L, 607 tests; First floor: average 0.9 pCi/L, 82 tests
19081Basement: average 2.7 pCi/L, 1,739 tests; First floor: average 1.5 pCi/L, 306 tests
19082Basement: average 2.3 pCi/L, 2,841 tests; First floor: average 1.1 pCi/L, 694 tests
19083Basement: average 3.0 pCi/L, 8,162 tests; First floor: average 1.8 pCi/L, 1,294 tests
19085Basement: average 2.4 pCi/L, 1,955 tests; First floor: average 1.4 pCi/L, 464 tests
19086Basement: average 2.9 pCi/L, 2,853 tests; First floor: average 1.7 pCi/L, 514 tests
19087Basement: average 5.7 pCi/L, 12,385 tests; First floor: average 3.6 pCi/L, 2,801 tests
19094Basement: average 2.1 pCi/L, 416 tests; First floor: average 1.1 pCi/L, 52 tests
19096Basement: average 3.1 pCi/L, 4,474 tests; First floor: average 1.9 pCi/L, 960 tests
19113Basement: figures not shown
19153Basement: average 0.9 pCi/L, 259 tests; First floor: average 0.6 pCi/L, 62 tests
19312Basement: average 6.2 pCi/L, 5,455 tests; First floor: average 4.0 pCi/L, 1,193 tests
19317Basement: average 2.5 pCi/L, 2,878 tests; First floor: average 1.5 pCi/L, 421 tests
19319Basement: average 3.8 pCi/L, 50 tests; First floor: figures not shown
19342Basement: average 2.7 pCi/L, 3,277 tests; First floor: average 1.6 pCi/L, 509 tests
19373Basement: average 3.4 pCi/L, 632 tests; First floor: average 1.8 pCi/L, 109 tests
19382Basement: average 3.0 pCi/L, 13,001 tests; First floor: average 1.8 pCi/L, 2,090 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.

Radon Action Brief

National Radon Action MonthPre-sale

Delaware County's radon brief, in one dated file.

  • Your area's radon record, explained.
  • Your plan to test this week.
  • Fix costs and pros near you.

Save 64%Sale price: $8.99Price after the sale: $25Ends Jan 31Then $25

Get the Delaware County BriefSee a free sample

Area data, not a test of the building.

Local help

Delaware County, Local resources

Radon testing and mitigation in Delaware County

Who tests and fixes radon in Delaware County: listed businesses, Pennsylvania's radon program and test kits.

Listed radon businesses with an address in Delaware County:

Listed radon professionals by town: Brookhaven, Glenolden, Media

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...

What it means

Delaware County, Questions

Questions about radon in Delaware County

Common questions

8 questions, answered from the figures above

Who does radon mitigation in Delaware County?

No listed mitigator names Delaware County as a service area yet; the Pennsylvania directory lists 153 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.

Radon mitigation: how it worksRadon mitigation costRadon mitigation systemsMitigators in Pennsylvania

How do I get a radon test in Delaware 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 radon testing business listed on Radon411 has an address in Delaware County or names it as a service area yet. The Pennsylvania radon program is the place to ask about certified testers and any test kit offer it runs.

Radon testing: how to test a homeRadon test kits comparedFree and low-cost kits by stateRadon Action Month checklistPennsylvania radon program

Are radon levels high in Delaware County?

In 2020, 14.7% of the radon tests reported to CDC for Delaware County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.8 pCi/L. That is a share of reported tests, not of homes. EPA places Delaware County in Zone 1, highest predicted potential, a predicted average indoor screening level greater than 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.

Radon levels: what a result meansWhat is radon?Radon levels in Pennsylvania

What EPA radon zone is Delaware County in?

EPA places Delaware County, Pennsylvania in Zone 1, which EPA describes as highest 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 Delaware 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 Delaware County?

Delaware County borders 5 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.

If you own, buy, sell or rent

What these figures mean for each reader, with the guide that covers it

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

Delaware County in figures

The figures above, said in words

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

    • Predicted

      Predicted

      EPA places Delaware County in Zone 1, highest predicted potential, as it does 48 other counties of Pennsylvania's 67.

      Of the 5 bordering counties, EPA places Chester County and Montgomery County in Zone 1, Gloucester County, NJ and New Castle County, DE in Zone 2 and Philadelphia County in Zone 3.

  • Reported tests

    Measured

    CDC has annual figures for Delaware County for 7 years, 2014 to 2020. In 2020, 14.7% of 6,041 reported tests were at or above 4 pCi/L.

    Across those years the share ranged from 14.7% (2020) to 20.7% (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 Chester, Yeadon and Lansdowne; the figures here cover them as part of the county.

Products

Delaware County, Products

Testing and mitigation products

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

Test kits and monitors42

See all products

As an Amazon Associate, Radon411 earns from qualifying purchases.

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

Testing

5

Mitigation

3

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Delaware County, Bordering counties

Counties bordering Delaware County

Calculated by Radon411
Why bordering counties matter

5 counties share a boundary with Delaware County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.

Delaware County, Cities and towns

Cities and towns in Delaware County

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

  • Chester
  • Yeadon
  • Lansdowne
  • Darby
  • Collingdale
  • Brookhaven
  • Ridley Park
  • Glenolden
  • Clifton Heights
  • Folcroft
  • Swarthmore
  • Prospect Park
  • Sharon Hill
  • Norwood
  • Media
  • Aldan
  • Chester Heights
  • Upland
  • Morton
  • East Lansdowne
  • Colwyn
  • Eddystone
  • Marcus Hook
  • Parkside
The other 4 places in Delaware County
  • Trainer
  • Millbourne
  • Rose Valley
  • Rutledge

28 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.

Delaware County, Next steps

What to do next

  1. LearnKnow what radon isWhat radon is, how it gets indoors, and why a county zone is not a reading for your home.Learn about radon
  2. TestTest the building you live inShort-term or long-term, where the device goes, and closed-house conditions.How to test
  3. FixBring a high level downHow a mitigation system works, and the retest that confirms it.How mitigation works
  4. Find a proHire a certified professionalMeasurement and mitigation professionals by state, with their certifications.Find a professional

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.