Short answer: the median radon test in Butler County was 3.8 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 Butler County compares
Butler County’s median of 3.8 pCi/L ranks #34 of 67 Pennsylvania counties with CDC data. The middle Pennsylvania county median is 3.8 pCi/L, so Butler County is right at 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 Butler 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.
Kennihan Plumbing And Heating Inc
Certified firm based in Valencia, PA
PA DEP certified mitigationCertification #3536
William Kennihan
Listed with: Kennihan Plumbing (name cut short on the state list)
Certified individual based in Valencia, PA
PA DEP certified mitigationCertification #3535
Certified firms in neighboring counties
- Steel City Radon (Pittsburgh, Allegheny County)
- Radon Detection And Control (South Heights, Beaver County)
- Main Street Radon Remediation (Irwin, Westmoreland County)
- Restoration Contracting Services In (New Kensington, Westmoreland County)
Radon in counties next to Butler
| County | Median pCi/L | EPA zone |
|---|---|---|
| Allegheny, PA | 2.9 | Zone 1 (high) |
| Armstrong, PA | 4.8 | Zone 1 (high) |
| Beaver, PA | 3.9 | Zone 1 (high) |
| Clarion, PA | 3.8 | Zone 1 (high) |
| Lawrence, PA | 3.3 | Zone 2 (moderate) |
| Mercer, PA | 3.0 | Zone 2 (moderate) |
| Venango, PA | 3.8 | Zone 1 (high) |
| Westmoreland, PA | 3.1 | Zone 1 (high) |
What to do in Butler 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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