Chapter 5 - Quality Assurance & Quality Control
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Post-Mitigation Testing

Best Practice

A best practice is for homeowners to engage a third party, independent testing company for pre and post mitigation testing. However, national radon standards suggest the following best practices to ensure mitigation contractors obtain results on the effectiveness of their systems:

  • The contractor may leave an approved radon test kit with the person responsible for the building and instructs that person, in writing, that a radon test should be performed using the supplied radon test kit or any other approved radon test kit
  • The contractor may hire a certified or licensed, or both, independent radon tester to perform the required radon test
  • The contractor may use any available post-mitigation test results such as from a relocation company that has arranged for post-mitigation testing.

Post-Mitigation Test Requirements

Post-mitigation testing should be conducted under standard protocols.  Additional protocols include the following considerations:

  • Conduct the test in the same location as the pre-mitigation test(s) when possible.
  • Conduct  an additional post-mitigation test in the lowest livable area above any crawlspace that is structurally isolated from the occupiable or tested rooms; and in the lowest livable area above each other unique structural area.
  • Post-mitigation tests should be initiated no sooner than 24 hours and no more than 30 days after a system has been installed and operational.
  • Systems should be retested every 2 years.