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AdvancedGeo Environmental WM-V. 10 April 2017 AGE-NC Project No. 12-2169 Page 4 of 6 Health Administration, U.S. Coast Guard and U.S. Environmental Protection Agency, October 1985. Notify the RWQCB and SJCEHD a minimum of 72 hours prior to commencement of any work, following the date of issue for drilling and/or well permits. All drilling locations will be marked at least 48 hours in advance for an Underground Service Alert (USA) check of underground utilities or pipes. 3.1.1. Soil-Vapor Boring Advancement and Sampling Soil borings SVI-1 and SVI-2 will be advanced utilizing a 4-inch diameter stainless steel hand auger. Upon reaching the total depths, soil borings SVI-1 and SVI-2 will be converted into semi-permanent soil-vapor point using a three-inch long vapor implant attached to %-inch diameter Teflon tubing. The six-inch implant and tubing will be lowered to the total depth of each boring (i.e. 61/2 ft) and filter pack material consisting of #2/12 sand will be placed from the bottom of the borehole to approximately 1/2 foot above the vapor implant (i.e. 5 - 6 1/2 ft). Following filter placement, approximately 1/2 foot of dry granular bentonite will be placed above the filter pack (i.e. 4 Y2- 5 ft). The remainder of the void space between the tubing and the open borehole will be filled with a neat cement with 1-5% bentonite content at depths between 1/2- 41,4 feet bsg. The as-built construction of the soil-vapor sampling well is depicted in Figure 4. 3.1.2. Soil-Vapor Sampling Following soil-vapor well installations, a minimum 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 5. Above ground, the surface around the soil-vapor tubing will be sealed and hydrated 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). A sample of the interior shroud air will be collected within a tedlar bag (1 liter) during sampling and analyzed for IPA.