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CJeologicaC7eckrcics inc, • • Page 3 Fonzia SGWI Report Project No.: 774.2 June 10, 1999 ' 1.0 SCOPE OF INVESTIGATION GTI advanced 4 additional boreholes utili ing the GeoProbe® direct-push method to further define the lateral and vertical extent of petroleum hydrocarbon-impacted soil and groundwater beneath the site. 1.1 Borehole Drilling & Soil Sample Collection On May 24 & 25, 1999, GTI conducted' additional site characterization. Four GeoProbe boreholes (GP-14 through GP-17)were advanced at the locations indicated on Figure 2. The I boreholes were drilled with a GeoProbe® drilling rig owned and operated by V&W Drilling of Rio Vista, CA (C57# 720904). The Ge Probe®rig advances a continuous coring tool with a pneumatic hammer to a selected depth. The soil sample enters an acetate cylinder ' contained in the coring tool. Upon filling, the coring tool is pulled from the borehole and the soil cylinder is removed. A selected interval(s) was cut from the cylinder and preserved for laboratory analysis. The remainder of th soil sample was used for geologic logging and ' subjectively field-screened with an organic vapor meter (OVM). The OVM is a portable photo-ionization detector that uses a 10.0 eV lamp to detect compounds with ionization potentials below 10.0 eV (hydrocarbon range). All collected soil samples were sealed with plastic end caps, labeled, and placed in a cooler chilled to 4° Celsius for transport to the ' laboratory following Chain of Custody (COC)protocol. The sediments were logged by a GTI geologist under the supervision of Ray Kablanow, a I California registered geologist. The soils were logged according to the Unified Soil Classification System (USCS) and recorded with field observations on borehole logs (Appendix C). Soil samples were collected at depths pre-approved by the SJC PHS/EHD for each boring: • Boring GP-14 was drilled to approximately 37 feet bgs, and soil samples were collected at 12, 19, 28, and 33 feet bgs. • Boring GP-15 was drilled to approximately 11.5 feet bgs and soil samples were collected at 9 and 11 feet bgs. • Boring GP-16 was drilled to approximately 12 feet bgs. A soil sample was collected ' at 12 feet bgs. • Boring GP-17 was drilled to approximately 12 feet bgs. Soil samples were collected from 9 and 12 feet bgs. ' The soil samples were submitted for the rc quested analyses to the State-certified laboratory, BSK Analytical Laboratories (BSK) in Fre no, California under COC protocol. ' 1.2 Groundwater Sample Collection Groundwater samples were collected with a HydroPunch®-type sampler at depths pre- approved by the SJC PHS/EHD for each boring. The groundwater samples were gently transferred into 1-liter amber glass bottles pd Y2-liter poly bottles. The bottles were labeled and placed in a cooler at 4° Celsius for transport to the laboratory following COC protocol. ' Clean surgical gloves are worn at all times in handling of the sample and sampling equipment. All down-hole equipment was cleaned with an Alconox solution and pressure washed between each sampling interval. The joints in the drill rods were additionally sealed with factory o-rings and teflon tape to prevent cross-contamination. 1