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29 March 2018 AdvancedGeo AGE Project No. 18-4345 Environmental Page 3 of 4 SOIL-VAPOR SAMPLING AGE proposes to advance one boring at the northern property boundary for installation and sampling of a temporary soil-vapor well. The soil boring will be advanced to a completion depth of 5 feet bsg utilizing a 3-inch hand auger. Once the total depth is reached, a single-completed soil-vapor point will be installed in the boring as illustrated in Figure 2. For installation of the soil-vapor point, a temporary/disposable vapor-tip and 1A-inch Teflon tubing will be lowered to the base of the boring at approximately 5 feet bsg; two feet of tubing will remain outside the borehole for vapor sample collection. Once the tubing and vapor-tip are in place, a filter pack of #3 sand will be placed from the bottom of the borehole to one-foot above the vapor tip. Following placement of the filter pack, one-foot of dry bentonite crumbles will be placed atop the filter pack. Thereafter, bentonite will be hydrated to surface grade. Following soil-vapor point installation, a minimum of one-hour stabilization period will be observed prior to sample collection at the vapor point location. A one-liter Summa canister and a 6-liter purge canister will be connected together with a dedicated and serialized sampling inlet manifold. The sampling inlet manifold will consist of an air/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 controller and connections for both purge and sampling canisters (manifold assembly). The manifold assembly will be attached to the -1/4-inch Teflon® tubing from the vapor sampling location. The purge canister will be attached to the end of the sampling manifold while the sample canister will be attached to the tee-fitting between the tubing and purge container. Prior to purging and sample collection, a leak test will be performed on the soil-vapor sampling 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 the assembly. Upon achieving a successful leak test, the purge canister valve will be opened for a calculated period of time to allow for three 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. 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.