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26 September 2014 AGE Project No. 13-2675 Page 5 of 6 intrusion. Once vapor wells are set, a two-hour equalization time will be observed prior to sampling. One six-liter Summa canister will be utilized for purging and each soil-vapor sample will be collected in a one-liter Summa canister (TO-15). The sampling and purge canisters will be connected together with a dedicated and serialized sampling inlet manifold. The sampling inlet manifold will consist of a 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 flow controller and connections for both purge and sampling canisters (manifold assembly). The manifold assembly will be attached to the tubing from the temporary/disposable vapor-tips. The purge canister will be attached to the end of the sampling manifold while the sample canisters will be attached to the tee-fitting between the tubing and purge container. Leak tests will be performed on each manifold 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. Each soil-vapor boring location will be isolated from ambient air by enclosing the borehole, tubing and manifold/canister assembly in a plastic shroud, which will be weighted at the surface. Isopropyl alcohol (IPA) as a liquid will be placed in a stainless steel bowl within the plastic structure and allowed to volatilize into the air enclosed within the plastic structure surrounding the borehole, tubing and manifold/canister assembly. Upon achieving a successful leak test and allowing for 120 minutes of equilibration time, 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. The purge volume will be determined by calculating the internal volume of the tubing and open borehole area (approximately four minutes). 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 sample canister valve will be closed and final pressure and time recorded. The sampling port on the sampling canister will be capped with a brass end-cap. The samples will be transported under chain-of-custody procedure to a CDPH-certified laboratory. Each sample canister will be labeled with sample designation, time, date and sampler's initials and analyzed for TPH-g, VOCs, and IPA by EPA Methods 82606 and TO-15. Advanced GeoEnviron mental,Inc.