MAH_2019

Protocol for Conducting Measurements of ANSI/AARST MAH 2019 Radon and Radon Decay Products in Homes 16 8.5.9.3 Additional report advisories Informative Advisory —Additional advisories are recommended when observations suggest the possibility of higher concentrations under different test conditions. Examples include: — Observance of Non-ASD passive, pressurization or dilution mitigation methods “Within the first year after mitigation efforts, repeat post-mitigation testing procedures to verify that effectiveness is retained for both the heating season and the cooling season.” Note—Non-ASD systems include passive efforts, such as only sealing openings to soil, new construction radon piping without a fan or ventilation openings to outdoor air; and active mechanical systems intended to pressurize or add outdoor air to indoor airspaces. — Observance of geologic considerations for the region (e.g., Karst) “Confirming low test results by repeating tests during different seasons and weather conditions or with long-term testing can be especially important for certain geological regions. If a foundation is connected to a sub-surface cavity system that connects to radon- producing strata, these geologic and topographic characteristics have been correlated with 8.5.9.2 Reporting Low Concentrations EQUIVALENT STATEMENTS FOR THESE ADVISORIES SHALL BE INCLUDED IN THE REPORT • Consider fixing the building if test results indicate radon concentrations greater than half the action level, (e.g., between 2 and 4 pCi/L). • Note that tests conducted when heating systems are active both day and night are more likely to provide a clear characterization of potential radon hazards. Advisories required regarding continued protection against long-term exposure to a radon hazard • Retest the building at least every 5 years or, to verify continued effectiveness of radon mitigation systems or efforts, at least every 2 years. • Retest in conjunction with any sale of new or existing buildings. • In addition, be certain to test again when any of the following circumstances occur: ü a new addition is constructed or alterations for building reconfiguration or rehabilitation occur; ü a ground contact area not previously tested is occupied, or a home is newly occupied; ü heating or cooling systems are significantly altered, resulting in changes to air pressures or pressure relationships; ü ventilation is significantly altered by extensive weatherization, changes to mechanical systems or comparable procedures; ü significant openings to soil occur due to: — groundwater or slab surface water control systems that are altered or added (e.g., sumps, perimeter drain tile, shower/tub retrofits, etc.) or, — natural settlement causing major cracks to develop; ü earthquakes, construction blasting, or formation of sink holes nearby; or ü a mitigation system is altered, modified or repaired.