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TO E RO E K SOP No.026,REV.1 ASSOCIATES,INC INDOOR AIR AND SUB-SLAB SOIL GAS SAMPLING METHODS I PAGE 9 7. Install and hydrate quick-drying Portland cement(no additives) in the annular space of the 3�4- to 1-inch hole. Allow the cement to dry according to manufacturer's instructions (typically 15 to 20 minutes). 8. Confirm the valve of the SUMMA®canister is closed and remove the brass cap.Attach the pressure gauge and flow controller (integrated system) to the canister.Attach the soil probe to the sample train with Teflon®or equivalent tubing. Note: some SUMMA® canister models utilize a quick-connect system and do not require the removal of brass caps. For quick-connect SUMMA® canisters, disregard further mentions of removal and replacement of the brass cap 9. Once fitted with the sampling tube, the ambient air within the sampling train is purged. Note: an optional and additional "T" valve assembly can be inserted into the sampling tube to serve as purge valve on/off switch if desired. Usually, 3 to 5 system volumes are purged prior to sample collection. If the sampling system purge volume cannot be measured, then a standard purge time of 3 to 5 minutes should be used. A PID may be used to purge ambient air while also providing a qualitative means to indicate when purging is complete (i.e., when VOCs are detected).A syringe may also be used to purge the sampling train a minimum of five times only if the volume of the syringe is greater that the sampling train and a secure shut off valve is installed a dosed properly between purge volumes. 10.After the system is purged of ambient air but before the pump is turned off, turn the purge "T"valve to the off position or if a"T"valve assembly is not being used, fold the sample tubing over itself(approximately 2 inches of the sampling line) closest to the entrance port of the pump. The tubing should be securely clamped to keep ambient air from reentering the system. After the purged system is sealed to ambient air, the pump should be turned off. Sample collection can now proceed using a SUMMA® canister. 11. Open the canister valve counterclockwise until fully opened, which will allow the evacuated canister to draw in soil gas, and immediately record the canister pressure reading and time.Also,record the initial vacuum of the canister. Note: some SUMMA®