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GeosyntecO <br /> consultants <br /> 4.3 Soil Vapor Probe Installation and Sampling <br /> 4.3.1 Drilling and Geologic Logging <br /> Soil vapor sampling locations will be selected and marked at each site prior to drilling. Because of <br /> the iterative nature of the proposed sampling, additional locations will be marked to anticipate <br /> step-out sample locations. The soil borings will be drilled by a C57-licensed drilling contractor <br /> using a direct-push drilling rig.The continuous geologic core from the direct-push drilling will be <br /> logged by a Geosyntec field staff under the direction of a California Professional Geologist using <br /> the Unified Soil Classification System (USCS). The geologic boring logs will include <br /> classification of encountered soils, sampling depths, drilling observations, and the total boring <br /> depth. The geologic boring logs will be used to select depths for soil vapor probe installation. <br /> 4.3.2 Soil Vapor Probe Installation and Sampling <br /> At each sample location, a soil vapor probe will be inserted into the soil, sealed at the surface <br /> using bentonite clay, and then purged and sampled through a Teflon®tube into a Tedlar®bag <br /> (for HAPSITEV analysis)or SummaTM canister(for laboratory analysis). In general, soil vapor <br /> probe installation and sampling will follow Advisory Active Soil Gas Investigations, published <br /> jointly by the DTSC, Los Angeles Regional Water Quality Control Board(LARWQCB), and <br /> San Francisco Bay Regional Water Quality Control Board (SFRWQCB) (DTSC et al, 2015). <br /> Soil vapor probes will be installed in accordance with the soil vapor sampling SOP, included in <br /> Appendix B. Probes may be installed at up to two depths per location between 5 and 20 feet bgs <br /> based on the subsurface lithology observed and previous HAPSITE® results. <br /> Following soil vapor probe installation and prior to sampling, each probe will be allowed to <br /> equilibrate a minimum of two hours. Soil vapor probe purging and sampling activities will be <br /> conducted in accordance with the soil vapor sampling SOP(Appendix B). <br /> 4.3.3 Site Restoration and Waste Management <br /> Soil borings will be properly destroyed in accordance with local and State regulations following <br /> all sampling activities. The surface of each boring will be completed to match the original <br /> surface. <br /> Soil cuttings generated during the investigation will be stored in properly labeled drums, <br /> temporarily staged, and characterized prior to off-site disposal by a licensed waste hauler. <br /> 202012 Lincoln Center Soil Vapor Assessment Work Plan 8 December 2020 <br />