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06 January 2017 AGE-NC Project No. 01-0877 Page 5 of 6 Following sample collection, each preserved sample sleeve will be labeled with the boring location, depth, time, date, and sampler's initials. Appropriately sealed and labeled samples will be placed in a chilled container and transported under chain of custody to a State of California Department of Public Health (CDPH)-certified laboratory. Laboratory reports of soil analysis, testing methods, laboratory quality assurance/quality control (QA/QC) reports, and sample chain of custody documentation will be presented in a report of findings and recommendations. 3.1.3. Soil-Vapor Sampling Following soil-vapor well installations, a 48-hour stabilization period will be observed prior to sample collection at each of the vapor point well locations. A one-liter Summa canister and a 6-liter purge canister will be connected together with a dedicated and serialized sampling inlet manifold. The sampling inlet manifold will consist of an air/vapor-tight valve; a particulate filter; a calibrated flow restrictor calibrated to 200 milliliters per minute (ml/min), a stainless steel tee-fitting, two vacuum gauges at either end of the controller and connections for both purge and sampling canisters (manifold assembly). The soil vapor sampling train is depicted in Figure 6. Above ground, the surface around the soil-vapor tubing will be sealed with bentonite to prevent ambient air intrusion. To ensure that a reliable soil-vapor sample is collected with no ambient air breakthrough, AGE will apply approximately 6 to 8 ounces of isopropyl alcohol (IPA) as a tracer to adequately wet cotton balls; the wetted cotton balls will be placed next to the sampling tubing and then cover the entire sampling train with a large see-through plastic shroud. Measurements of the organic vapor concentrations will be collected from within the shroud during the process and recorded, to determine if sufficient tracer compound is present (detected as the starting values). Prior to sample collection, each soil-vapor well will be purged a total of three purge volumes. The purge volume will be determined by calculating the sum of the internal volume of the Teflon tubing, the soil vapor point and the volume of the boring trace. Leak tests will be performed on each soil-vapor sampling assembly by attaching and securing the sample and purge canisters to the manifold and opening the valve on the purge canister and the manifold. The leak test will be performed for approximately 10 minutes on each assembly. Upon achieving a successful leak test, the purge canister valve will be opened for a calculated period of time to allow for three calculated volumes of air to be purged. The purge canister vacuum gauge will be monitored to ensure a proper decrease of vacuum ensuring flow and purging. Upon achieving the targeted purge volume, the purge canister valve will be closed and the sample canister valve will be opened. The initial pressure and time will be recorded. Upon reaching at least 5 in Hg or less, the sampl e canister valve will be closed and final Advanced GeoEnvironmental,Inc.