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03 June 2015 • AGE Project No. 15-3325 Page 3 of 4 Soil gas samples will be obtained along the northern property boundary at depths of five and fifteen feet bsg. Samples will be collected using a Geoprobe soil-vapor assembly. An expendable vapor point will be placed into a point holder at the bottom of an assembly of 1.25-inch diameter drive rods. The assembly will then be advanced to the specified depth and retracted approximately 6 to 12 inches to disengage the expendable point and expose a column of strata from which soil vapor can be extracted. A single use, '/<-inch diameter disposable teflon tubing is then attached to a tubing adapter equipped with an O-ring to ensure a vacuum-tight seal. The adapter assembly is then lowered through the center of the Geoprobe hollow drive rods to the specified depth and secured by threading into the expendable vapor point holder. A stabilization time of 20 minutes will follow boring placement. For collection of soil-vapor samples within the warehouse and show room, a small diameter steel probe sampler with retractable screened vapor point will be driven into the subsurface with a mechanical hand-held hammer (rotohammer). The sampling point will be advanced to depths of 5 and 10 feet bsg and then retracted to approximately 6 inches at each depth in order to expose the screen from which soil-vapor can be extracted. Single use, '/<-inch disposable polyethylene tubing will be attached through the rods to the sampling point tubing adapter equipped with an O-ring to ensure a vacuum-tight seal. Each sampling point will be purged for a minimum of 2 minutes prior to obtaining a sample in 1-liter Tedlar bags. Once the purging is complete, a sample will be collected using a peristaltic pump and low-flow sampling techniques (200 milliliters per minute). After the sample is collected, the Tedlar bag will be labeled and stored in a dry container. Above ground at all borings, the surface around the soil vapor sampler will be sealed with a bentonite sealant to prevent ambient air intrusion. The end of the teflon tubing is attached by a two-way inlet port to a Tedlar bag placed inside an SKC Vac-U-Chamber vacuum chamber. A vacuum pump attached to a purge port of the vacuum chamber is then used to purge the exposed soil column, through the sampling tubing and inlet port, until approximately three volumes of soil-vapor or ambient air is evacuated through the sampling system. The vacuum chamber is then sealed and the vacuum pump is attached to a vacuum outlet port of the chamber. When vacuum is applied to the chamber, a negative pressure is created around the Tedlar bag, which inflates, allowing the soil-vapor sample to enter directly into the bag via the inlet port. When the sample is collected, the negative pressure in the chamber is reduced and the sample bag is sealed, labeled, log on a chain-of-custody form, and place into a dry cooler (room temperature). Subsequently, all of the collected soil-vapor samples will be transported under chain-of-custody procedure to a CDPH-Certified laboratory for analysis of TPH in the gasoline range and VOCs by EPA method 8260. EQUIPMENT DECONTAMINATION Advanced GeoEnvironmental,Inc.