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PEW; Wx Rk , i W+ bearing zone have well developed soil rofiles and consequently Profiles Y poor permeability. The base of the shallow zone is poorly defined and probably is from five to twenty feet belowround generally surface. -�'he qualify of the shallow groundwater in the Tracy area is of g l; y poor quality, , 4.0 INVESTIGATIVE I TRODS ANI2 PROCEDURES 4.1 Soih- To assess the Iateral and vertical extent of soil contamination beneath the site RES NA drilled eleven shallow soil borings and 3 deeper borings in the tank and product line areas. The shallow borings were drilled to 7 feet below grade (Figure 3) using a 2 inch solid flight auger. The deeper borings were drilled to depths of 20 feet below grade and completed as groundwater monitoring wells. All borings were sampled at 5.5 or 6.5 feet using a California modified lit-s !� g brass liners. The material from one poop sampler with sample ring was described and field screened with a photoicnization detector(PID)for possible volatile organic content. The second rin was at eacend with Teflon to g sealed r, h pe and a plastic cap. The cap was sealed with duct tape and the sample was preserved on ice and transported under strict chain-of-custody procedures to Sequoia Analytical Laboratory, a State certified laboratory. LIS Between sampling events, equipment was cleaned using a three bucket. wash In system. system, the rings and samplers were scrubbed with a brush in a bucket of tap Y flus detergent, then rinsed in a bucket of tap water and a final rinse of distilled watery, water and f One soil sample from each boring was submitted for laboratory analysis. All samples were E analyzed for BTEX, and TPHG b EPA Y methods 8020/8015 respectively, The sample collected near tank pit 2 (the waste oil tank) was also analyzed for lead, cadmium, zinc, and chromium by EPA methods 7421 and 6010 respectively. r i a-aingt.LF 3