RMS-LB 2018 with 12/20 Revisions

Companion Guidance—Section B CG AARST Companion Guidance RMS-LB 2018 Informational 2 Guidance when considering non-ASD methods ASD and Non-ASD methods When elevated radon concentrations are found, assemble a team of qualified professionals that includes an experienced mitigation professional. (See Section 3.2.1 for a “ Qualified Mitigation Professional .”) Keep in mind: Ø Aggressive source control for contaminants is a critical component in managing indoor air quality as in the examples of hazardous chemicals or microbial and bacterial contamination. Ø ASD is a source control method for radon and other soil air contaminants. Therefore compared to other mitigation methods, ASD will typically demonstrate far greater effectiveness in reducing indoor radon concentrations and of other soil air contaminants. Additionally: ASD provides significant benefits compared to other mitigation methods that include energy conservation and ease of maintenance so critical in maintaining a Long-Term Risk Management Plan. Ø Limitations of Non-ASD methods: Dilution alone is unlikely to be a practical solution if radon concentrations are high. For instance, unless the unit’s walls and floors are constructed or rendered to be a complete sealed isolation assembly , other mitigation methods beyond air mixing or additions of outdoor air will most often be needed if initial radon concentrations are above 10 pCi/L . The effects of pressurizing a building or individual airspace can be more pronounced yet each of these methods require rigorous diagnostic evaluations, inspections and maintenance for continued safety of occupants. o See Companion Guidance Section Table F-3 to gain a sense of complexity associated with HVAC inspection and maintenance that needs to be rigorously applied in order to expect long-term success in risk reductions. o Section Table F-4 also provides a sense of design parameters required for successful mitigation including certain failures in design if not accounted for. o See Section 12 and Section 10.4 for requirements of Non-ASD methods. These provisions seek to secure the continued safety of occupants. Radon Mitigation recommendation if radon reductions appear to result from incidental HVAC repairs or augmentation: Apply all requirements in Section 10 for “Long-Term Operation, Maintenance and Monitoring”. Such plans help ensure long-term benefits by means of labeling equipment and a routine inspection program. Important overview: Industry experience has been that all benefits are easily defeated when systems and controls, so volatile to unintended alteration, are not inspected regularly. Overall Indoor Air Quality: The presence of elevated radon gas concentrations can sometimes be an indicator of other indoor air quality concerns. Regardless of radon activities, HVAC systems should be maintained with regular inspections and repairs in a manner to ensure healthy indoor air quality. For further guidance: Information that inherently addresses indoor air quality issues relative to most large buildings can be found at EPA. (See http://www.epa.gov/iaq/schools.) EPA’s “ Tools For Schools Action Kit ” provides comprehensive tools for evaluation of ventilation systems under the Section for “Ventilation Checklist” and related “ backgrounder ” document. (See http://www.epa.gov/iaq/schools/actionkit.html ). Occupant symptoms that might guide or trigger an evaluation of indoor air quality and HVAC are described in EPA’s “ Problem Solving Tool ”. (See http://www.epa.gov/iaq/schools/problem_solving_tool.html . ) Additional guidance can be found in “ Indoor Air Quality Guide – Best Practices for Design Construction and Commissioning ” published by ASHRAE ( www.ashrae.org ) .