SGM-SF_2017with 12/20 Revisions

Additional Requirements—Chemical Vapor Intrusion 55 ANSI/AARST SGM-SF 2017 (with 1220 revisions) Soil Gas Mitigation Standards for Existing Homes 13.4.7 Soil gas retarder materials The contractor shall account for the known chemical(s) of concern in relationship to manufacturer guidance on soil gas retarder materials to help ensure degradation of the material will not occur over time when in contact with the chemical of concern. Informative advisory —For ASD systems that incorporate Sub-membrane Depressurization (SMD) and other active mitigation systems that pressurize or depressurize an airspace, such as indoor air pressurization ( Section 12.3 ), sustainability is the overwhelming priority. Success or optimization in these systems is most prominently reliant upon the durability of a closed air barrier at all points of its assembly. For situations where the purpose of the membrane is to help prevent liquids or gases from passing through membrane materials, less permeable products than specified in Section 7.6.1 (soil gas retarder material) should be considered. 13.4.8 Labeling for soil gas mitigation (chemical vapor) All system components shall be labeled in accordance with Section 8.4 . 13.5 Post-Mitigation Inspections 13.5.1 Functional inspection 13.5.1.1 ASD Additional PFE Measurements In conjunction with activating an ASD system, the suction in system piping at the main riser (e.g., Fan Monitor) and all other locations where PFE tests are made shall be measured and recorded for inclusion in the system(s) OM&M plan. Informative advisory — PFE Goals: Goals for the degree of PFE demonstrated should support the likelihood of continuous success in adequately reducing soil gas entry. 13.5.1.2 Appropriate Design Required All mitigation systems and methods shall meet the needs for an appropriate design ( Section 5.3 ). Note—To achieve requirements in Sections 5.3 , optimal evidence of effectiveness provided by PFE measurements for airflow and vacuum capacity should indicate not less than but also not excessively more than needed to consistently reduce soil gas entry. 13.5.1.3 Inspection for compliance Note—See Section 8.5 . 13.5.1.4 Review with client(s) Note—See Section 8.6 . 13.5.1.5 Post-Mitigation Testing for Chemicals of Concern Due to various considerations, qualified soil gas mitigation professionals are not required under this standard to ensure post- mitigation measurements of hazardous chemical vapors or other substances are conducted. 13.6 Rapid Response Situations 13.6.1 Addressing urgent situations For the purposes of this document, “Rapid Response” denotes situations when action is required quickly or immediately due to hazards present. See A-1.3 for descriptions of situations that can warrant a rapid response. Informative advisories—Rapid response actions can include: a) Vacating the Property When acute safety concerns are present and cannot be immediately mitigated, occupants and workers should be evacuated from the building until safe conditions can be established. b) Enhanced Ventilation Ventilation with outside air is normally the first consideration as a temporary means to enhance safety. However, care must be exercised for any temporary effort. The amount of ventilation immediately achieved may not be adequate to achieve safe conditions. In addition, ventilation with outside air is seldom viable as a permanent solution. See Section 12.4 . c) Mechanical Solutions A variety of mechanical systems can often be temporarily augmented or installed to enhance safety. Care must be exercised for all temporary efforts since the amount of reduced hazard achieved may not be adequate for achieving safety. Rapid response options include: