SITE INFORMATION AND CORRESPONDENCE

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l l � GEOMATRIX 1 with the most affected soil observed within the off-site boring,if applicable, or that observed in 1 other on-site borings (56 to 67 feet bgs). Another soil sample was collected at the terminus of 1 each of these borings (69 to 80 feet bgs). l Soil samples were collected in 6-inch stainless-steel sleeves and sealed with Teflon sheets, plastic end caps, and silicon tape. Soil samples were labeled, sealed in plastic bags, and placed immediately in an ice-cooled chest for subsequent delivery to the analytical laboratory, tL� Friedman and Bmya, Inc. (F&B),of Seattle, Washington (a California-certified laboratory), under Geomatrix chain-of-custody (COC) procedures. ^� 2.3.2 Grab Groundwater Sampling First groundwater was encountered at about 40 to 45 feet bgs in the borings located within the Bellini property and about 35 to 37 feet bgs in the borings located downgradient and off site. Grab groundwater samples were collected from borings SB-15, SB-17, SB-18, and SB-21 to ,..1 assess the vertical extent(SB-15 and SB-21) and lateral extent(SB-17 and SB-18) of petroleum hydrocarbons in groundwater. The grab groundwater samples from SB-15 and SB-21 were collected at a depth between about 96 and 100 feet bgs. The grab groundwater samples from SB-17 and SB-18 were collected at a depth between about 46 and 50 feet bgs. Petroleum- affected soil was observed(i.e.,petroleum odor, PID readings, and/or soil discoloration) at the depth interval of first groundwater encountered in borings SB-16, SB-19, and SB-20. As such, grab groundwater samples were not collected from these three borings as the samples would likely be subject to positive interferences from petroleum-affected sediment and the analytical results would not be representative of dissolved petroleum hydrocarbons in groundwater. At SB-15 and S13-21, the sonic drive casing was driven about 15 to 20 feet past the deepest ` affected soil observed prior to grab groundwater sampling. Grab groundwater samples were collected by driving the HydroPunch sampler approximately 5 feet ahead of the sonic drive casing. The sleeve of the sampler was then retracted 4 feet to expose a 1-inch diameter Schedule 40 polyvinyl chloride(PVC)screen (0.010-inch slot size) to the water-bearing unit. A small-diameter bailer was lowered into the PVC piping to collect a grab groundwater sample. The groundwater sample was then decanted from the bailer into acidified 40-milliliter volatile organic analysis (VOA) vials and 1-liter amber glass bottles provided by the laboratory. Sample containers were labeled, sealed in plastic bags, and stored in an ice-cooled chest for delivery to F&B under COC procedures. 1:IPROJEC1\5000s\5011.00015011-03.do 7 l