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Radon Levels in Montgomery County, Pennsylvania

EPA puts Montgomery 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
21.8%of 10,508 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

Montgomery County, At a glance

Montgomery 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 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Montgomery County, 2020

Tests reported
10,508
At or above 4 pCi/L
21.8%
Median result
2.0 pCi/L
Reported results by concentration band, Montgomery County, 2020
Under 2 pCi/L: 49%2 to 4 pCi/L: 29%4 pCi/L and above: 22%

Of 10,508 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Montgomery County, 2020: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L5,11348.7%
2 to 4 pCi/L3,10329.5%
4 pCi/L and above2,29221.8%

CDC publishes this figure only for counties here, so there is no state or national number to compare Montgomery 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 Montgomery 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 Montgomery 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 (10,508 for 2020). The median is the middle result of those tests, not of buildings. CDC also reports the number of buildings tested (6,972), a different count, so the two totals are not interchangeable.

Montgomery 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. Montgomery 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. 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).

Montgomery County, State data

Pennsylvania's own radon test data

Measured

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

Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 71 ZIP codes that lie wholly or partly in Montgomery County, each with the state's own figures for it. Period: Period not stated by DEP.

ZIP codes in Montgomery County
ZIP codeWhat the state reports
18041Basement: average 4.8 pCi/L, 647 tests; First floor: average 2.7 pCi/L, 126 tests
18054Basement: average 4.7 pCi/L, 635 tests; First floor: average 2.7 pCi/L, 111 tests
18070Basement: average 8.8 pCi/L, 114 tests; First floor: figures not shown
18073Basement: average 4.5 pCi/L, 1,575 tests; First floor: average 2.2 pCi/L, 202 tests
18074Basement: average 3.7 pCi/L, 982 tests; First floor: average 2.0 pCi/L, 156 tests
18076Basement: average 3.4 pCi/L, 357 tests; First floor: average 1.8 pCi/L, 55 tests
18914Basement: average 5.3 pCi/L, 6,254 tests; First floor: average 2.9 pCi/L, 1,201 tests
18915Basement: average 3.1 pCi/L, 251 tests; First floor: average 2.1 pCi/L, 35 tests
18936Basement: average 3.3 pCi/L, 318 tests; First floor: average 1.7 pCi/L, 101 tests
18964Basement: average 3.7 pCi/L, 2,395 tests; First floor: average 1.8 pCi/L, 453 tests
18969Basement: average 3.8 pCi/L, 2,572 tests; First floor: average 2.1 pCi/L, 543 tests
19001Basement: average 3.3 pCi/L, 3,855 tests; First floor: average 2.1 pCi/L, 1,231 tests
19002Basement: average 4.3 pCi/L, 9,243 tests; First floor: average 2.6 pCi/L, 1,954 tests
19003Basement: average 2.5 pCi/L, 3,078 tests; First floor: average 1.3 pCi/L, 723 tests
19004Basement: average 4.0 pCi/L, 3,050 tests; First floor: average 2.0 pCi/L, 596 tests
19006Basement: average 4.4 pCi/L, 5,146 tests; First floor: average 2.5 pCi/L, 1,211 tests
19009Basement: average 7.2 pCi/L, 129 tests; First floor: average 3.7 pCi/L, 41 tests
19010Basement: average 3.2 pCi/L, 4,858 tests; First floor: average 1.7 pCi/L, 1,151 tests
19012Basement: average 3.3 pCi/L, 1,794 tests; First floor: average 2.4 pCi/L, 442 tests
19025Basement: average 3.7 pCi/L, 1,780 tests; First floor: average 1.9 pCi/L, 409 tests
19027Basement: average 4.5 pCi/L, 3,409 tests; First floor: average 2.2 pCi/L, 794 tests
19031Basement: average 4.7 pCi/L, 1,395 tests; First floor: average 2.5 pCi/L, 321 tests
19034Basement: average 3.9 pCi/L, 1,897 tests; First floor: average 2.5 pCi/L, 465 tests
19035Basement: average 4.5 pCi/L, 1,593 tests; First floor: average 3.2 pCi/L, 329 tests
19038Basement: average 4.1 pCi/L, 6,178 tests; First floor: average 2.4 pCi/L, 1,422 tests
19040Basement: average 3.4 pCi/L, 3,463 tests; First floor: average 1.9 pCi/L, 808 tests
19041Basement: average 3.9 pCi/L, 1,595 tests; First floor: average 1.9 pCi/L, 348 tests
19044Basement: average 4.3 pCi/L, 3,019 tests; First floor: average 2.2 pCi/L, 1,057 tests
19046Basement: average 5.4 pCi/L, 4,404 tests; First floor: average 3.4 pCi/L, 938 tests
19066Basement: average 3.9 pCi/L, 1,983 tests; First floor: average 1.8 pCi/L, 401 tests
19072Basement: average 4.4 pCi/L, 3,187 tests; First floor: average 2.5 pCi/L, 685 tests
19075Basement: average 4.0 pCi/L, 2,212 tests; First floor: average 2.4 pCi/L, 566 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
19087Basement: average 5.7 pCi/L, 12,385 tests; First floor: average 3.6 pCi/L, 2,801 tests
19090Basement: average 2.4 pCi/L, 3,062 tests; First floor: average 1.5 pCi/L, 934 tests
19095Basement: average 5.6 pCi/L, 1,423 tests; First floor: average 3.3 pCi/L, 340 tests
19096Basement: average 3.1 pCi/L, 4,474 tests; First floor: average 1.9 pCi/L, 960 tests
19118Basement: average 4.5 pCi/L, 2,852 tests; First floor: average 2.4 pCi/L, 854 tests
19128Basement: average 3.2 pCi/L, 6,261 tests; First floor: average 2.1 pCi/L, 1,180 tests
19401Basement: average 2.9 pCi/L, 4,852 tests; First floor: average 1.8 pCi/L, 1,262 tests
19403Basement: average 4.5 pCi/L, 10,231 tests; First floor: average 2.5 pCi/L, 2,092 tests
19405Basement: average 3.0 pCi/L, 722 tests; First floor: average 1.9 pCi/L, 112 tests
19406Basement: average 4.4 pCi/L, 4,378 tests; First floor: average 3.8 pCi/L, 946 tests
19422Basement: average 3.9 pCi/L, 6,232 tests; First floor: average 2.1 pCi/L, 1,610 tests
19426Basement: average 4.2 pCi/L, 12,309 tests; First floor: average 2.5 pCi/L, 1,783 tests
19428Basement: average 3.5 pCi/L, 3,917 tests; First floor: average 2.3 pCi/L, 800 tests
19435Basement: average 4.9 pCi/L, 36 tests; First floor: figures not shown
19436Basement: average 5.4 pCi/L, 82 tests; First floor: figures not shown
19437Basement: average 5.3 pCi/L, 448 tests; First floor: average 2.3 pCi/L, 102 tests
19438Basement: average 3.8 pCi/L, 5,671 tests; First floor: average 2.3 pCi/L, 1,107 tests
19440Basement: average 3.4 pCi/L, 3,158 tests; First floor: average 1.6 pCi/L, 802 tests
19444Basement: average 3.8 pCi/L, 3,057 tests; First floor: average 2.6 pCi/L, 833 tests
19446Basement: average 4.1 pCi/L, 13,140 tests; First floor: average 2.0 pCi/L, 3,243 tests
19453Basement: average 9.4 pCi/L, 165 tests; First floor: figures not shown
19454Basement: average 3.7 pCi/L, 6,636 tests; First floor: average 1.9 pCi/L, 1,767 tests
19456Basement: average 4.8 pCi/L, 166 tests; First floor: average 2.6 pCi/L, 41 tests
19460Basement: average 4.7 pCi/L, 12,115 tests; First floor: average 2.5 pCi/L, 1,760 tests
19462Basement: average 4.0 pCi/L, 2,156 tests; First floor: average 2.4 pCi/L, 589 tests
19464Basement: average 4.0 pCi/L, 8,254 tests; First floor: average 2.2 pCi/L, 1,063 tests
19468Basement: average 4.3 pCi/L, 6,399 tests; First floor: average 2.7 pCi/L, 859 tests
19472Basement: figures not shown; First floor: figures not shown
19473Basement: average 3.6 pCi/L, 3,542 tests; First floor: average 2.2 pCi/L, 530 tests
19474Basement: average 3.0 pCi/L, 522 tests; First floor: average 1.3 pCi/L, 148 tests
19477Basement: average 4.3 pCi/L, 132 tests; First floor: average 1.5 pCi/L, 44 tests
19490Basement: average 5.4 pCi/L, 340 tests; First floor: average 2.7 pCi/L, 93 tests
19492Basement: average 7.8 pCi/L, 127 tests; First floor: figures not shown
19504Basement: average 10.7 pCi/L, 1,036 tests; First floor: average 7.9 pCi/L, 133 tests
19505Basement: average 8.2 pCi/L, 497 tests; First floor: average 4.5 pCi/L, 40 tests
19512Basement: average 10.6 pCi/L, 2,668 tests; First floor: average 6.6 pCi/L, 238 tests
19525Basement: average 4.1 pCi/L, 3,305 tests; First floor: average 2.4 pCi/L, 247 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

Montgomery 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 Montgomery County BriefSee a free sample

Area data, not a test of the building.

Local help

Montgomery County, Local resources

Radon testing and mitigation in Montgomery County

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

Listed radon businesses with an address in Montgomery County:

Listed radon professionals by town: Pottstown, Lansdale, Collegeville, Royersford, Green Lane

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

Montgomery County, Questions

Questions about radon in Montgomery County

Common questions

8 questions, answered from the figures above

How do I get a radon test in Montgomery 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 Montgomery 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 Montgomery County?

In 2020, 21.8% of the radon tests reported to CDC for Montgomery County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.0 pCi/L. That is a share of reported tests, not of homes. EPA places Montgomery 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

Who does radon mitigation in Montgomery County?

No listed mitigator names Montgomery 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

What EPA radon zone is Montgomery County in?

EPA places Montgomery 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 Montgomery 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 Montgomery County?

Montgomery County borders 6 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 Montgomery County, Pennsylvania in 2020. They describe tests other people carried out in other buildings, and none of them measures yours.

Montgomery County in figures

The figures above, said in words

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

    • Predicted

      Predicted

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

      Of the 6 bordering counties, EPA places Berks County, Bucks County, Chester County, Delaware County and Lehigh County in Zone 1 and Philadelphia County in Zone 3.

  • Reported tests

    Measured

    CDC has annual figures for Montgomery County for 7 years, 2014 to 2020. In 2020, 21.8% of 10,508 reported tests were at or above 4 pCi/L.

    Across those years the share ranged from 21.8% (2020) to 26.5% (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 Norristown, Pottstown and Lansdale; the figures here cover them as part of the county.

Products

Montgomery County, Products

Testing and mitigation products

Whatever the figures for Montgomery 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.

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

Testing

5

Mitigation

3

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Montgomery County, Bordering counties

Counties bordering Montgomery County

Calculated by Radon411
Why bordering counties matter

6 counties share a boundary with Montgomery 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.

Montgomery County, Cities and towns

Cities and towns in Montgomery County

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

  • Norristown
  • Pottstown
  • Lansdale
  • Conshohocken
  • Hatboro
  • Souderton
  • Ambler
  • Bridgeport
  • Collegeville
  • Telford (part)
  • Royersford
  • Jenkintown
  • Narberth
  • Trappe
  • Pennsburg
  • Hatfield
  • North Wales
  • East Greenville
  • Rockledge
  • Red Hill
  • West Conshohocken
  • Bryn Athyn
  • Schwenksville
  • Green Lane

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

Montgomery 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.