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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 (B4-2) was drilled to a total depth of 18.0 feet bgs and was located approximately 10 feet away from the southern edge of the former tank (Figure 2). Soil samples were collected at depths of 12 and 17 feet for laboratory analysis. Samples were collected using a 2-foot long, 1-inch diameter, Large-Bore Soil Sampler equipped with a clear acetate plastic liner. A groundwater sample was collected after the boring had been advanced to the total depth of 18 feet bgs using the method described above. Based on the lack of field evidence of PHC-impacted soil or groundwater, Margaret Lagorio and Carol Oz of PHS/EHD decided that the third boring planned for the site was unnecessary and provided verbal authorization to complete the investigation 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 r 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. This 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. According to BSK, these ICP methods provide the same detection limits as the ICP/MS method while offering the advantage of being able to accommodate analysis of turbid water samples. This change in analytical method for lead analysis was conveyed to -- Carol Oz. 4.0 INVESTIGATION FINDINGS Findings of the investigation, including geologic and hydrologic characteristics, and analytical results of the soil and groundwater samples, are discussed in the following sections. 4 98I MWVRPTS1s4USTINV.RPT