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Groundwater in the area flows generally to the northeast following surface topography. The site elevation ranges from 140 to 170 feet MSL. A series of groundwater monitoring wells have been installed at the site to monitor discharges from the wastewater treatment ponds. Groundwater is encountered at depths ranging from 70 feet below grade at the south end of the site to approximately 50 feet below grade at the north side of the site. FIELD INVESTIGATION During the week of August 19,2002 Owens-Brockway removed the two large ASTs. The larger of the two tanks had been constructed on an asphalt pad. The smaller tank was constructed directly on the ground. On August 27,2002 CKG Environmental,Inc.(CKG)arrived at the site to observe the soil for stains and collect shallow soil confirmation samples. The demolition contractor was on site with a large excavator to assist with the shallow soil sampling. CKG walked the perimeter and footprint of each former tank location. No visible stains were observed in the vicinity of the larger tank. Visible staining was observed in the vicinity of the smaller tank at the edge where the product distribution piping entered the tank. Figure 1 below illustrates how the soil staining appeared at the time CKG was present. CKG had the contractor excavate three trenches across the former tank locations(Plate 3). The first trench(T-1) extended from the visible stain to the middle of the smaller tank location. The second trench(T-2)extended from the center of the large tank to its southern edge. The third trench(T-3)extended from the end of T-1 the rest of the way across the smaller tank location. ,f A total of 9 soil samples were collected at the locations shown on Plate 3. Soil samples T-1-1 to T-1-3 were `�:;,!¢ W', collected to assess the stained soil and the potential �- bottom of impact. Soil samples T-2-1 through T-2-3 were confirmation samples for the large tank. Soil samples T-3-1 and T-3-2 assessed a smaller stain - observed in T-3,and T-3-3 and T-3-4 were confirmation samples. Chemical Analysis Figure 1 Visible staining at T-1. Extends Soil samples were submitted to McCampbell Analytical from ground surface to a depth of Laboratory for quantitative chemical analysis for total approximately 6 feet. petroleum hydrocarbons quantified in the motor oil range. McCampbell analytical is certified by the State of California to perform the requested analysis. The result for each sample is shown on Plate 3. The analytical laboratory report is attached. AST Soil Sampling Report,Owens-Brockway Tracy 2 September 24,2002 CKG Environmental,Inc.