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bottom of the boring to the surface Prior to collecting the groundwater sample, the depth-to- water was measured using an electric water-level sounder lowered into the PVC tubing. One quarter-inch diameter Teflon tubing, equipped with a check valve at the submerged end, was ' then inserted into the slotted PVC tube. Groundwater was brought to the surface within the Teflon tube by moving the Teflon tube up and down in a piston-like motion ' A second boring (B2-2) was drilled to a total depth of 21 0 feet bgs and was located approximately 40 feet away from the eastern edge of the former tank (Figure 2). Soil samples ' were collected at depths of 15 and 20 feet bgs for laboratory analysis Samples were collected using a 2-foot long, 1-inch diameter, Large-Bore Soni Sampler equipped with a clear plastic liner A groundwater sample was collected at a depth of 16 feet bgs using the method ' described above Based on the lack of field evidence of PHC-impacted soil or groundwater, Carol Oz of PHS/EHD decided that a third boring planned for the site was unnecessary and ' provided verbal authorization to complete the investigation at Site 2 with two borings. Both borings were subsequently grouted to the surface with neat cement per PHS/EHD guidelines ' Soil and groundwater samples were placed in an ice-cooled chest and submitted under chain-of- custody procedures to BSK Analytical Laboratories (BSK), a California DHS-certified laboratory for PHC analyses. Samples were analyzed for BTEX, TPHg, and MTBE using ' EPA Methods 8020/8015. The Work Plan stated that EPA Method 200 8 would be used for analysis of lead in soil and water samples Thus method uses inductively coupled plasma and mass spectrometry (ICP/MS) as the analytical technique and is typically used on low turbidity drinking water samples However, due to the high turbidity in water samples collected during this investigation, BSK performed lead analyses for water samples using EPA Method 200.7. ' Soil samples were analyzed using EPA Method 6010 Both these methods use ICP as the analytical technique and, according to BSK, these ICP methods provide the same detection limits as EPA Method 200 8, while offering the advantage of being able to accommodate ' analysis of turbid water samples. This change in analytical method for analysis of lead was conveyed to Carol Oz. 1 3.2 SI['I'E 3 ' Drillmg and sampling activities at Site 3 were conducted on August 7. The initial boning (B3- 3) was drilled to a total depth of 41 feet below bgs and was located near the southwestern corner of the former UST excavation (Figure 3). Continuous-core samples were collected from this boring to a depth of 20.5 feet bgs using the Macro-Core Open Tube Sampler as described ' above The Macro-Core Sampler was unable to be used below this depth because the walls of the boring became unstable due to swelling of clay layers or wet, saturated sands caving into the boring. This resulted in the core barrel becoming clogged with sediment while attempting 5 981174NVRy NSBUSMN R r ]AWLBOYAJIAN & ROSS, INC Environmental Scientists & Engineers