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AEI Project No. 337833 December 18, 2014 Page 3 of 5 • Boring SV-1 will be advanced adjacent to the onsite residence, in the southeast corner of the subject property. • Boring SV-2 and SV-3 will be advanced along the southern boundary of the subject property. • HP-1 will be advanced along the southern boundary of the subject property. • HP-2 will be advanced in the southwest corner of the subject property. Borings SV-1 through SV-3 will be advanced to a planned depth of approximately 5 feet bgs for the collection of soil gas samples. No soil samples will be collected. Borings HP-1 and HP-2 will be advanced to a planned depth of approximately 35 feet bgs or to first encountered groundwater, whichever is shallower, for the collection of groundwater samples. Groundwater is expected at approximately 33 to 78 feet bgs. It is anticipated that three groundwater sample will be analyzed from each boring. Groundwater Sample Collection Groundwater sampling will be attempted using the Geoprobe SP-15 groundwater sampling device. The direct-push tooling will be advanced to depth. Once at the target depth, the sheath covering the SP-15 screen will be removed exposing the internal stainless steel screen. Groundwater samples will be collected using either a disposable bailer or peristaltic pump and decanted into the appropriate sample containers. The containers will be sealed so that no head-space or air bubbles are visible within the containers. Soil Gas Sample Collection The scope of work proposed consists of soil gas sampling from a total of 3 locations (Figure 2). The sampling will be conducted in accordance with the guidelines outlined in Advisory Active Soil Gas Investigations document dated April 2012 by the DTSC. The purpose of each boring is listed below: • Boring SV-1 will be advanced adjacent to the onsite residence, in the southeast corner of the subject property. • Boring SV-2 and SV-3 will be advanced along the southern boundary of the subject property. The soil gas samples will be collected at a depth of 5 feet bgs using a soil gas well. Lengths of Teflon° tubing with screened tips will be placed near the bottom of the borings through 3/4-inch PVC casing. The probe tips will then be covered with approximately one foot of clean sand. The remainder of the boreholes will be filled to near surface with granular bentonite, hydrated in 6 inch lifts. Shutoff valves will be attached to the surface ends of the tubing. Vapors in the boreholes will be allowed to equilibrate for a minimum of two hours before sampling. Sampling will consist of vacuum testing the connections and purging with the use of a tracer compound. The samples will be collected through a calibrated flow controller and into 1-liter