MALB_2014 with 1-21 Revisions

Conducting Measurements of Radon and Radon ANSI/AARST MALB-2014 with 1/21 Revisions Decay Products in Schools and Large Buildings 30 2. Where mitigation methods are based on passive methods or mechanical dilution or pressurization of indoor air and clearance testing has not been conducted during two different seasons. d) Radon Sources Other Than Soil Gas Where testing indicates a possible radon source other than soil gas entry on upper floors or elsewhere in the building, recommendations regarding evaluations and post- mitigation testing shall be consistent with Normative Appendix C . e) Ongoing operation, maintenance and monitoring (OM&M) Where post- mitigation testing has indicated concentrations that are below the action level , summary reports shall: 1. recommend retesting every 2 years to verify continued mitigation system effectiveness, and 2. include guidance required in Section 8.2.5 whenever reporting low test results. 8.2.7 Other guidance requirements Guidance in summary reports and otherwise provided shall comply with all requirements of this Section 8.2.7 . a) Opinions and interpretations When opinions and interpretations on any topic are included, the basis upon which the opinions and interpretations have been made shall be included in test reports. Opinions and interpretations shall be clearly marked as such in a test report. b) Health guidance Health and action level guidance provided in reports or otherwise furnished shall be consistent with federal guidance or as required by the state or equivalent local jurisdiction of authority where the test is conducted. Note— Section 7.1 provides an additional informational resource related to such guidance. c) Longer test periods Longer test periods, such as those greater than 90 days, shall not be reported as a closer evaluation of annual average radon concentrations when, in accordance with Section 5.1.4 , heating season conditions during the test were less than the percentage of year when heating systems are active. d) Occupied versus unoccupied evaluations Evaluations of occupied versus unoccupied radon concentrations shall be permitted in summary reports to aid mitigation decisions when conducted in accordance with Section 5.2 . e) Extended testing protocol Where the Extended Testing protocol option was chosen, it shall be recommended that test results achieved from Steps 1 and 2 of the protocol, in accordance with Section 5.4.1 , are to be used for mitigation decisions.