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IcVV Aug A S S O C I A T E S I N C 2_1 Drilling Activities t On April 23, 1998, an ATC geologist supervised the advancement of six soil borings to 21 feet below ground surface (bgs) Soil bonngs SB 1, SB2, and SB4 were placed in the vicinity of the former USTs, soil boring SB3 was placed in the vicinity of the former dispenser, and soil borings SB5 and SB6 were placed at the southern edge of the former excavation area A site plan with soil boring locations is shown on Figure 2 Fisch Environmental, California License C57 683865, advanced the borings using a truck mounted Geoprobe® narrow diameter rig employing direct push technology Soil samples were collected from bonngs SBI through SB6 at five-foot intervals in acetate sampling tubes 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 2_2 Soil Sampling and Analysis Each soil sample was field screened with a Photoionization Detector (PID) for the presence of volatile organic compounds Sample tubes were then 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 a State-certified American Environmental Network (AEN) laboratories, (DOHS Cert No 1172) for chemical analysis Selected soil samples were analyzed by AEN for total petroleum hydrocarbons as gasoline, ' (TPHg) by EPA method 8015 modified, benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA method 8020, oxygenate fuel additives by EPA method 8260, and total lead ' 2!3 Groundwater Sampling and Analysis One groundwater sample was collected from each boring at the depth groundwater was first encountered, approximately 20 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-nng seals and an expendable drive point provided a watertight system to ensure sample integrity ' 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to the desired depth, extension rods were sent downhole to brace the bottom of the sample screen as the tool casing was retracted When the casing was retracted, approximately 41-inches of screen with slot sizes of 0 004 inches was exposed Teflon tubing with a check valve attached to one end was inserted down the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 i chain-of-custody documentation to AEN for chenucal analysis Following soil and groundwater sample collection, the borings were backfilled with neat cement grout to the ground surface W 113o99VeportslsunL&c 3