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PROCEDURES The soil borings were drilled on April 12, 1994 using a truck-mounted drill rig equipped with 8-inch-diameter hollow-stem augers. The CME 75HT drill rig and two man crew were supplied by Mitchell Drilling Environmental Corp. of Rancho Cordova. All four borings were drilled to a depth of 20 feet. Soil samples were collected at 5-foot intervals, using a 140-pound hammer to advance an 18- inch split-tube sampler loaded with three brass sample sleeves. The number of blows required to advance the sampler 18 inches in 6-inch increments was recorded on the boring log (see Boring Log). To avoid cross contamination, the sampling equipment was washed in a tri-sodium phosphate (TSP) solution and rinsed twice with water prior to each sampling run. After removal from the sampler, the ends of the bottom tube were covered with sheets of aluminum foil, capped, and sealed with tape. Samples were labeled, logged on the boring log, and stored on ice. Selected samples were transported under chain-of-custody to Sparger Technology Inc. in Sacramento, California for analysis. Soil in the middle and upper tubes was extruded and described on the boring log. The soil samples were screened for the presence of organic vapors using a photo-ionization detector (PID: Thermo Environmental 580A). The soil borings were then backfilled to surface with a bentonite-concrete slurry. The backfilling was witnessed by Mr. Michael Collins of the San Joaquin County Public Health Services - Environmental Health Division (PHS/EHD). The sample collected at 20 feet from each boring was analyzed for total petroleum hydrocarbons (TPH as gasoline and diesel), volatile aromatics (BTE&X) and total lead in accordance with EPA methods 8015m, 8020 and 7420, respectively. FINDINGS Mostly silty clays were encountered in the borings. Occasional silts and sands were also encountered (see Boring Log). No organic vapors were detected by the PID in any samples collected. Toluene was detected in the sample at 20 foot from boring B-4 at a concentration of 0.025 µg/g (parts per miIlion). No other petroleum hydrocarbons were detected in any of the samples analyzed. Total lead was detected in all four samples at levels of 14 ppm to 19 ppm. The results of the laboratory analyses are presented in Table 1. The laboratory report and chain-of-custody are attached. 0e 1.giw!Audit Service...I— 2 9244—Wog MSCJq.