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ATIL S A S S O C I A T E S I N C . �r 4.• PHS/EHD. The scope of work completed in phase one included obtaining permits, advancing four soil borings using direct push technology, soil and grab groundwater sampling, and the laboratory analysis of selected soil and groundwater samples. V 2.1 Drilling Activities On July 13, 1998, a geologist from ATC Associates supervised the advancement of four soil borings to depths of 26 to 31 feet below ground surface (bgs). A site plan showing soil boring locations is included as Figure 2. Fisch Environmental, California License C57 683865, advanced `w the borings using a truck mounted Geoprobe® narrow diameter rig employing direct push technology. Soil samples were collected at five-foot intervals in acetate sampling tubes beginning at four feet bgs and were described according to the Unified Soil Classification System. Descriptions of soil types encountered and sample collection intervals are presented on the boring logs contained in Appendix A. r 2_2 Soil Sampling Each soil sample was field screened with a Photoionization Detector (PID) for the presence of volatile organic compounds. The maximum PID reading was from soil sample SB4-25' at approximately 191 parts per million (ppm). Sample tubes were sealed at each end using Teflon tape and plastic end caps, labeled, and placed on ice. Selected soil samples were kept on ice and delivered under chain-of-custody documentation to State-certified Sequoia Analytical (ELAP #1210) for chemical analysis. Field notes are contained in Appendix B. boo 2.3 Groundwater Sampling �- One groundwater sample was collected from each boring at the depth groundwater was first encountered, approximately 24 feet bgs. A Geoprobe® Screen Point 15 Groundwater Sampler was threaded onto the leading end of the Geoprobe after groundwater had been encountered. When the sampler was advanced, O-ring seals and an expendable drive point provided a watertight system to ensure sample integrity. `r When the tool was advanced to the desired depth, extension rods were sent downhole to brace the bottom of the sample screen as the tool casing was retracted. When the casing was retracted, y approximately 41-inches of screen with slot sizes of 0.004 inches was exposed. Teflon tubing with a check valve attached to one end was inserted down the casing until it was immersed in groundwater. Water was then pumped through the tubing and to the ground surface by oscillating the tubing up and down. Groundwater samples were placed on ice and delivered under chain-of-custody documentation to State-certified Sequoia Analytical for chemical analysis. Following soil and groundwater sample collection, the borings were backfilled with neat cement grout to the ground surface. w:\14981\14981\rcports\psii.doc 2 V