Choose one of the following options:
1. Assume the project is in a high-risk radon area and install a passive ventilation system as outlined in the prerequisite. This option is highly encouraged because installing a radon system after construction completion can be difficult.
2. Do not install a passive ventilation system and complete the following steps: Test for radon at the completion of the project using either a long-term or short-term test. For multiple residential buildings on a site, contact GBCI for sampling options.
• Long-term test (30+ day test): Conduct a single long-term test. If the result is less than 4 pCi/L (150 Bq/m3), no remediation is needed and the prerequisite is satisfied. If the result is 4 pCi/L (150 Bq/m3) or greater, install an active radon mitigation system. Once the active mitigation system is installed, undergo another test (short-term or long-term) to confirm that the mitigation system is operating as needed. OR;
• Short-term test (