PA DEP radon standards
https://aged-wiki.win/index.php/When_Your_Well_Water_Needs_Radon_Treatment:_What_York_County_Homeowners_Should_Know
PA DEP radon standards set the acceptable levels of radon gas in Pennsylvania homes, requiring mitigation when readings hit 4 picocuries per liter or higher. The state's Department of Environmental Protection offers testing kits and guidance on fixing elevated levels, which is crucial since radon is a leading cause of lung cancer after smoking.