Pennsylvania

Radon Test Data by Zip Code

Agency Pennsylvania Department of Environmental Protection

The Pennsylvania Department of Environmental Protection (DEP) publishes Radon Test Data by Zip Code among its radiation protection reports. Its Radon Division, in the Bureau of Radiation Protection, runs a certification program for radon testing, mitigation and laboratory analysis. DEP says Pennsylvania has one of the most serious radon problems in the country, and that an estimated 40 percent of homes tested in the state have radon above the Environmental Protection Agency's action guideline of 4 picocuries per liter (pCi/L).

In a Phase I ESA

ASTM E1527-21 does not name radon test data among its standard record sources, and it lists naturally occurring radon among its non-scope considerations, which the user and the environmental professional may add by agreement. A lender or program may ask for radon testing; HUD's requirements for an FHA multifamily loan are on the Radon on an FHA multifamily loan page.

Zip code data is not the building's result. DEP's page for homeowners links the zip code search, then says the smartest course is to test the home itself, wherever it is. Use the zip code data as background, and do not report it as a result for the building.
Radon-in-air testing takes a certification. The Radon Certification Act required DEP to set up, by regulation, certification for persons who test for radon, analyze radon devices in a laboratory and mitigate radon in buildings; the regulations are 25 Pa. Code Chapter 240. Each of the three activities needs its own certification. DEP says testing certification is required for placing and retrieving any radon testing device. Where radon testing is contracted as an additional service beside a Phase I, check that whoever places the devices holds it. DEP does not certify persons who provide radon in water testing and laboratory analysis to the public; it only lists them.
Individual or firm. Only the certified individual may work under an individual certification. A firm must employ at least one certified individual responsible for the activity, and other employees may do the work once DEP approves it in writing.
DEP checks the certified. DEP's Radon Monitoring Section runs ongoing performance evaluations of certified laboratories, and inspects certified testers and mitigators to verify that they follow the regulations and protocols.
A mitigation system has its own checks. DEP tells owners to check the U-tube manometer on the system's piping to see that the fan is running, and to retest every two years. It says the installer should run a follow-up test once the system has run at least 24 hours. Where radon is among the agreed additional services and a building has a system, ask for the installer's follow-up test and the latest retest.

Where to look a site up

Radon Test Data by Zip Code, linked from DEP's Radiation Protection Reports and Radon Monitoring and Public Outreach pages.
DEP's Radon Services Directory, where DEP says certified individuals and firms are listed. Its homeowner page calls it the mitigator list, sorted alphabetically by county.
The Radon Division's hotline is 800-237-2366 and its phone 717-783-3594. Its Radon in the Home page gives the mailbox ra-epbrpenvprt@pa.gov; the Radon Division page points to DEP's contact page for email.

Getting the file

The pages read do not say whether DEP keeps radon test results for individual buildings or how to ask for them, so ask the owner for any test reports and mitigation records. DEP lists radon monitoring and remediation in its radiation protection program, which is in the Southeast, Southcentral and Southwest regional offices. For DEP's records in general, DEP recommends its Environmental Site Assessment Search Tool or an Informal File Review, requested on a form and scheduled with the regional office, before a request under the Right-to-Know Law. The file review and the Right-to-Know request are on the Informal File Review and Right-to-Know requests page.

Sources

Pennsylvania Department of Environmental Protection pages, read October 15, 2026, no modified date shown:

Pennsylvania Department of Environmental Protection pages, read October 1, 2026, no modified date shown: