radon retest verification 3

https://high-wiki.win/index.php/Radon_Ballwin:_What_Homeowners_Need_to_Know_About_Testing_and_Mitigation

For your radon retest verification, you'll need to submit a follow-up measurement done after any mitigation steps. This confirms levels stay below the action limit. Expect to place the detector in the same lowest livable area for at least 48 hours. Results usually come within two weeks, and the lab report serves as your official proof.