how to verify radon contractor 2

https://alpha-wiki.win/index.php/Radon_Pros_York_PA_Address_Growing_Demand_for_Residential_Testing_and_Mitigation

To verify a radon contractor, start by checking if they hold a current state or national certification, such as from the National Radon Proficiency Program (NRPP). Ask for proof of liability insurance and references from recent local jobs. A reliable contractor will also explain their testing or mitigation plan clearly, use calibrated equipment, and provide a written report with their findings and recommendations.