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AGE Standard Operating r locedures AdvancedGeo <br />Geoprobe Soil Borings Environmental <br />Page 5 of 6 <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 />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 />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 />The samples will be transported under chain-of-custody procedure to a California <br />Department of Public Health (CDPH)-certified laboratory. Each sample bag will be labeled <br />with sample designation, time, date and sampler's initials and analyzed for Volatile <br />organic compounds (VOCs) and Isopropyl alcohol (IPA) by EPA Method 8260B.