Short answer: the median radon test in Montgomery County was 2.2 pCi/L (CDC, lab tests 2008 to 2017). That is under EPA’s action level of 4 pCi/L but in the 2 to 4 range where EPA suggests considering a fix. Because it is a median, many homes in the county tested higher.
How Montgomery County compares
Montgomery County’s median of 2.2 pCi/L ranks #62 of 67 Pennsylvania counties with CDC data. The middle Pennsylvania county median is 3.8 pCi/L, so Montgomery County is below the state’s typical county. EPA puts the county in Zone 1, the highest-potential zone on EPA’s map (predicted average indoor level above 4 pCi/L).
These numbers come from tests homeowners and buyers chose to run, not a random survey. They show local risk; they cannot predict the level in your house.
Certified radon mitigation pros based in Montgomery County
Each listing below appears on Pennsylvania DEP’s certified mitigation list dated September 1, 2026. We show the city on file and the DEP certification number so you can confirm it.
Accurate Radon Control Inc
Certified firm based in Green Lane, PA
PA DEP certified mitigationCertification #2113
Airotox
Certified firm based in Lansdale, PA
PA DEP certified mitigationCertification #3109
Radon Technology & Enviromental Inc
Certified firm based in Royersford, PA
PA DEP certified mitigationCertification #1308
Radon-Rid LLC
Certified firm based in Phoenixville, PA
PA DEP certified mitigationCertification #2586
Bruce Kollmeyer Jr.
Listed with: Radon Techn (name cut short on the state list)
Certified individual based in Royersford, PA
PA DEP certified mitigationCertification #3024
David Demar
Listed with: Accurate Radon Contr (name cut short on the state list)
Certified individual based in Green Lane, PA
PA DEP certified mitigationCertification #2112
David Yorgey
Certified individual based in Conshohocken, PA
PA DEP certified mitigationCertification #3758
Marc A. Marino
Listed with: Radon-Rid LLC
Certified individual based in Phoenixville, PA
PA DEP certified mitigationCertification #2585
Mark Achuff
Listed with: Airotox
Certified individual based in Lansdale, PA
PA DEP certified mitigationCertification #2741
Roger Burens Jr.
Listed with: Air Quality Co (name cut short on the state list)
Certified individual based in King of Prussia, PA
PA DEP certified mitigationCertification #1862
Thomas Hollingsworth
Listed with: The Radon Bro (name cut short on the state list)
Certified individual based in Perkiomenville, PA
PA DEP certified mitigationCertification #2749
Timothy J. Gentry
Certified individual based in Horsham, PA
PA DEP certified mitigationCertification #2217
Certified firms in neighboring counties
- S. J. Watras, Inc. (Boyertown, Berks County)
- Indoor Air Surgeons, LLC (Bensalem, Bucks County)
- The Radon Bros (Quakertown, Bucks County)
- Safe Shelter Environmental (West Chester, Chester County)
- Integra Environmental LLC (Allentown, Lehigh County)
- SWAT of PA (Allentown, Lehigh County)
- RVS Radon Mitigation, LLC. (Philadelphia, Philadelphia County)
Radon in counties next to Montgomery
| County | Median pCi/L | EPA zone |
|---|---|---|
| Berks, PA | 4.3 | Zone 1 (high) |
| Bucks, PA | 2.1 | Zone 1 (high) |
| Chester, PA | 2.2 | Zone 1 (high) |
| Delaware, PA | 1.9 | Zone 1 (high) |
| Lehigh, PA | 3.9 | Zone 1 (high) |
| Philadelphia, PA | 1.5 | Zone 3 (low) |
What to do in Montgomery County
- Test your home. EPA recommends testing every home below the third floor, whatever the county average.
- Fix it at 4 pCi/L or higher. EPA also suggests considering a fix between 2 and 4 pCi/L.
- Use a certified pro. In Pennsylvania, radon mitigation for pay requires DEP certification. Check the number against the state list before you sign.
- Retest after the system is installed.
Sources
- County median radon levels and test counts: CDC Environmental Public Health Tracking Network, radon tests from labs, 10-year period 2008 to 2017 (ephtracking.cdc.gov).
- Radon zones: U.S. EPA Map of Radon Zones (epa.gov/radon).
- Certified mitigation firms and individuals: Pennsylvania DEP list of certified radon mitigation firms dated September 1, 2026 (PDF), checked October 24, 2026.
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