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11 September 2020 <br />AGE Project No. 20-6107 <br />Page 5 of 6 <br />Advanced' - <br />Environmental <br />canister will be attached to the end of the stainless-steel sampling manifold while the <br />sample canisters will be attached to the tee -fitting between the'/4-inch Teflon(D tubing and <br />purge container. Teflon® tape will be placed on the threads of each open fitting of the <br />manifold assembly prior to attaching the '% -inch Teflon® tubing and sampling and purge <br />canisters (Figure 3). <br />Each canister's initial vacuum will be measured and recorded between -26 and -30 inches <br />of mercury (in hg). Shut-in tests will be performed on each assembly by attaching and <br />securing the sample and purge canisters to the manifold and opening the valves on the <br />purge canister and the manifold. The shut-in test is performed for approximately 10 <br />minutes on each assembly. <br />Each soil -vapor well location will be isolated from ambient air by enclosing the borehole, <br />tubing and manifold/canister assembly in a 100 -liter shroud. Isopropyl alcohol (IPA) will <br />be emitted into the shroud surrounding the well borehole, tubing and manifold/canister <br />assembly and acts as a tracer gas to evaluate if leaks in the sampling apparatus have <br />allowed infiltration of ambient air. <br />Upon achieving a successful leak test, the purge canister valve will be opened for a period <br />to allow the three calculated volumes of air to be purged. The purge vacuum gauge will <br />be monitored to ensure a proper decrease of vacuum purged. <br />Upon achieving the targeted purge volume, the purge canister valve will be closed, and <br />the sample canister valve opened. The initial pressure and time is recorded. Upon <br />reaching at least -5 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 soil -vapor samples will be transported under chain -of -custody procedures to a ELAP- <br />certified laboratory and analyzed for VOCs and IPA (tracer gas) in accordance with EPA <br />Method TO -15. <br />After collection of the sample, soil -vapor from the polyethylene tubing will be monitored <br />for the presence of volatile organics using an organic vapor meter equipped with a photo - <br />ionization detector (PID). <br />3.1.4. Boring Abandonment <br />All soil borings will be permanently sealed to prevent vertical migration of potential <br />contaminants. Soil borings shall be abandoned by backfilling with cement grout from the <br />total depth to surface grade. Borings will be abandoned with grout utilizing tremie <br />procedures. The top three to six inches of the boring abandonments will be completed <br />flush to surface grade with concrete. The EHD will be notified for grout inspection at least <br />48 hours prior to conducting grouting procedures. <br />