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Stantec PHASE 11 ENVIRONMENTAL SITE ASSESSMENT REPORT Field Activities March 31,2011 Soil vapor boreholes SV-6 was placed adjacent to the sewer lateral and is located south of the southern warehouse. 2.2.1.1 Soil Sampling During the hand augering of the soil vapor boreholes, soil samples were collected from each of the boreholes at the designated soil vapor probe depth. The soils encountered at the Site generally consisted of a light brown silty sand to the depth of 5 feet bgs. No soil discoloration or odors were observed during the excavation of the soil vapor boreholes. A photo-ionization detector was used to monitor the soils and breathing zone during the hand augering of the boreholes, no elevated readings were observed. A soil sample was collected from each of the boreholes at the designated soil vapor probe depth of 5 feet. The soil from the hand auger was placed in a laboratory supplied 16-ounce glass jar with a gloved hand. The soil was packed into the jar to minimize the headspace in the jar prior to sealing the jar with a lid. The soil samples were placed in a cooler with ice and sent via courier to BC Laboratories, Inc. (BC Labs), a California state-certified laboratory. The samples were shipped under chain-of-custody (COC) procedures. Selected soil samples from boreholes SV-1, SV-5 (parts washer area), and SV-6 (sewer lateral) were analyzed for total petroleum hydrocarbons (TPH) fuel fingerprint, volatile organic compounds (VOCs), and the CAM 17 metals. The remaining samples were placed on hold at BC Labs pending the soil vapor results. The soil samples from the soil vapor boreholes were identified as SS-1 through SS-6. 2.2.1.2 Soil Vapor Well Construction Once the maximum depth of the borehole was reached, a soil vapor well was constructed within each borehole. Each soil vapor well was constructed using a porous polypropylene implant set at approximately 5 feet bgs connected to %-inch diameter Nylaflow tubing extending above the ground surface. A '/: inch diameter section of PVC piping was placed around the implant and tubing to keep the vapor implant centered in the borehole during the placement of the sand pack. The PVC pipe was removed once the sand pack was in place. The sand pack consisted of 1 foot of number 2/12 sand was placed around each implant and extending above and below the implant screen. The sand pack was followed by approximately 1 foot of dry granular bentonite. After the dry granular bentonite was in place, on boreholes SV-1 through SV-5, hydrated bentonite was placed to the surface. The hydrated bentonite was mixed in a bucket above grade and placed into the borehole. The hydrated bentonite was gently packed in the annular space of the borehole to create a seal. In the traffic area were the borehole for SV-6 (in the driveway area next to the sewer lateral) was placed, the dry granular bentonite was followed by 2 feet of hydrated bentonite. The hydrated bentonite was mixed in a bucket above grade and gently packed in the borehole to create a seal. The upper 1 foot of borehole SV-6 was completed with a traffic rated box set in concrete. The traffic box was set slightly above grade so that drainage was away from the box. i:\projects\calpineVodi\reportVodi.svrpt.do" 2.2