York PA Radon Pros has launched a free online directory of certified radon mitigation companies serving York County, Pennsylvania, where state testing data shows basement radon levels averaging nearly ten picocuries per liter, approximately two and a half times the EPA action threshold of four point zero picocuries per liter. The site addresses a critical certification gap, warning homeowners that national credentials alone do not satisfy Pennsylvania DEP licensing requirements for radon contractors. - York County basement radon levels average close to 10 pCi/L based on over 18,000 DEP tests, placing the region at roughly 2.5 times the EPA action level of 4.0 pCi/L, the threshold at which the agency recommends mitigation. - Pennsylvania law requires its own DEP certification for any contractor who tests or mitigates radon for pay, meaning national  ...