SGM-SF_2017with 12/20 Revisions

Additional Requirements—Chemical Vapor Intrusion 53 ANSI/AARST SGM-SF 2017 (with 1220 revisions) Soil Gas Mitigation Standards for Existing Homes Note—Other evaluations such as comparing more stressed building pressure conditions can sometimes be warranted, subject to the discretion of the qualified soil gas mitigation professional ; and c) The post- mitigation condition immediately after installation shall also be documented in accordance with Section 13.4.1.1 . 13.3.3.2 PFE Test Locations The test locations for PFE evaluation shall include: a) no less than three locations for any residential structure; b) no less than one location for each slab floor of the building to include each basement, upper slab, garage and other slab-on-grade area that is greater than 64 square feet (6 m 2 ). Note—It is recommended to create and evaluate a PFE test location in each quadrant of the soil gas collection plenum ; c) To the extent that visual inspection or diagnostics indicate that a sub-slab area might be divided by footings or other obstruction, additional PFE test locations shall be created and evaluated as needed to characterize the nature and potential of multiple soil gas collection plenums ; c) no less than one location for each membrane installed over open soil; and d) locations chosen in a manner to evaluate conditions that are remote from the suction point , such as the most distant accessible slab locations. Informative advisory —Other locations of suspected concern should be evaluated for PFE based on the judgment and experience of the qualified soil gas mitigation professional . 13.3.3.3 PFE and Soil Gas Sampling Ports Locations determined to be appropriate for facilitating future inspection of PFE effectiveness and/or soil gas concentrations shall be identified and configured in a manner to result in permanent test ports. The test port locations shall be: a) prominently documented in the OM&M plan; b) reasonably accessible for future measurements without destructive or significant disassembly of building components or finishes; c) installed in a safe manner so as not to present hazards to occupants; and d) installed in a manner to help ensure that use of the permanent test port is not compromised over time, such as by: 1. implementing hardware to allow easy access and closure of the test port in a manner that facilitates cleaning out the test port in the future; and 2. removing a portion of packed fill or expansive soils that can often exist under a test port. The opening around test port penetrations of a slab or soil gas retarder shall be sealed in a permanent, airtight manner with appropriate materials and configuration to durably secure the test port in place. 13.3.3.4 Reporting and Records Requirements include: a) Ad-hoc Reporting The contractor shall provide the client timely notice of unexpected conditions revealed during visual investigations or diagnostics that can significantly impact occupant health, budgets, schedules or scope of work; b) Final Reporting The OM&M plan shall provide information and data sufficient to characterize PFE analysis as witnessed upon completion of the installation; and c) Future Data Logs The contractor shall record or advise the client to record test data from the test ports during each monitoring event subsequent to initial installation. 13.3.3.5 PFE Fluctuation Informational advisory —It is not uncommon for the test port data several weeks after installation (e.g., during the initial air testing) to be more representative of future PFE test data. It is thereafter not uncommon to see