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16 June 2016 <br />AGE Project No. 95-0167 <br />Page 4 of 5 <br />3.2. SOIL-VAPOR SAMPLING <br />Soil-vapor samples will be collected from the vapor wells using Summa canisters. For this <br />method, one six-liter Summa canister will be utilized for purging and each soil-vapor <br />sample will be collected in a one-liter Summa canister. The sampling and purge canisters <br />will be connected together with a dedicated and serialized sampling inlet manifold. The <br />sampling inlet manifold will consist of a vapor-tight valve; a particulate filter; a calibrated <br />flow restrictor, calibrated to 200 milliliters per minute (ml/min); a stainless steel tee-fitting; <br />two vacuum gauges at either end of the flow controller and connections for both purge <br />and sampling canisters (manifold assembly). The manifold assembly will be attached to <br />the 1h-inch Teflon® tubing from the vapor sampling locations. The purge canister will be <br />attached to the end of the sampling manifold while the sample canisters will be attached <br />to the tee-fitting between the tubing and purge container. <br />Leak tests will be performed on each manifold assembly by attaching and securing the <br />sample and purge canisters to the manifold and opening the valve on the purge canister <br />and the manifold. The leak test will be performed for approximately 3-5 minutes on each <br />assembly. <br />Each soil-vapor sampling location will be isolated from ambient air by enclosing the <br />borehole, tubing and manifold/canister assembly in a 100-liter plastic shroud, which will <br />be weighted at the surface. Isopropyl alcohol (IPA) as a liquid will be placed in a stainless <br />steel bowl within the plastic structure and allowed to volatilize into the air enclosed within <br />the plastic structure surrounding the borehole, tubing and manifold/canister assembly. <br />Upon achieving a successful leak test, the purge canister valve will be opened for a <br />calculated period of time to allow for a minimum of three calculated volumes of air to be <br />purged. The purge canister vacuum gauge will be monitored to ensure a proper decrease <br />of vacuum ensuring flow and purging. The purge volume will be determined by calculating <br />the internal volume of the tubing and open borehole area. <br />Upon achieving the targeted purge volume, the purge canister valve will be closed and <br />the sample canister valve will be opened. The initial pressure and time will be recorded. <br />Upon reaching at least -2 in Hg or less, the sample canister valve will be closed and final <br />pressure and time recorded. The sampling port on the sampling canister will be capped <br />with a brass end-cap. <br />The samples will be transported under chain-of-custody procedure to a CDPH-certified <br />laboratory. Each sample canister will be labeled with sample designation, time, date and <br />sampler's initials and analyzed for the constituents listed in Section 2.3. <br />Following sample collection the total VOC concentration in the wells will be measured <br />using a hand-held photo-ionization detector (PID; Mini Rae 3000). <br />Advanced GeoEnvironmental Inc.