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05 February 2015 AGE Project No. 14-3298 Page 3of5 tubing (PRT) was then attached to a tubing adapter (PRT adapter) equipped with a new disposable O-ring to ensure a vacuum-tight seal. The adapter assembly was lowered through the center of the hollow drive rods to the specified depth and secured by threading into the expendable vapor point holder (PRT Point Holder). Soil-vapor samples were collected from borings V-1 through V-4, and V-6 at ten feet bsg by installing a temporary soil-vapor well in the borings. Following collection of soil- vapor samples at five feet bsg, borings V-1 through V-4, and V-6 were advanced to ten feet bsg for installation of a soil-vapor well. For installation of the soil-vapor well, a temporary vapor implant and thirteen feet of '/4-inch Teflon tubing were lowered to the base of the previously advanced borehole; three feet of tubing was left outside the borehole for vapor sample collection. Once the tubing and vapor implant were in place, a filter pack of #3 sand was placed from the bottom of the borehole to 9.5 feet bsg. Following placement of the filter pack, dry bentonite crumbles were placed atop the filter pack. to eight feet bsg. Thereafter, bentonite was placed and hydrated from eight feet bsg to surface grade to seal the vapor well from ambient air intrusion. For collection of each soil-vapor sample, hydrated bentonite was placed around the drive rod or tubing at ground surface to prevent ambient air intrusion. Approximately 30 minutes equilibrium time was allowed at each location prior to purging and sample collection. Additionally, each soil-vapor boring location was isolated from ambient air by enclosing the borehole, tubing and Tedlar bag in a plastic shroud. Isopropyl alcohol (IPA) as a liquid was placed in a stainless steel bowl within the plastic shroud and allowed to volatilize into the air enclosed within the plastic shroud surrounding the borehole, tubing and Tedlar bag. Soil-vapor samples collected at five fee bsg were purged for approximately 1.75 to 2.25 minutes (three-four well volumes) prior to obtaining a sample in a 1-liter Tedlar bag; soil- vapor samples collected at ten feet bsg were purged for approximately 2.10 to 2.80 minutes (three-four well volumes) prior to obtaining a sample in a 1-liter Tedlar bag. Once the purging was complete a sample was collected using a peristaltic pump calibrated to 200 milliliters per minute. After sample collection, each Tedlar bag was labeled and stored in a dry container. SAMPLE ANALYSIS Soil-vapor samples were transported under chain-of-custody to Cal Tech Environmental Laboratories (CTEL), a California Department of Public Health (CDPH)-Certified laboratory and were analyzed for the following chemical constituents: • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA-method 8015-modified. Advanced GeoEnviron mental,Inc.