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`► *Moe 20 October 2004 AGE-NC Project No. 95-0184 Page 3 of 4 Sample VW3-40 and VW5-30 were analyzed for bioenumeration and physicochemical properties. Very low populations of both general and selective microbial populations were observed. Nitrogen concentrations were below optimal for biodegradation of hydrocarbons. Additional background information is summarized in the AGE-prepared Quarterly Report-August 1997. On 13 and 14 November 2001,two off-site,paired soil borings(CPT-2 and CPT-3)were advanced to a maximum depth of 180 feet bsg immediately south of the site (Figure 2) utilizing CPT technology. Based on the CPT data, AGE has developed a preliminary site hydrogeologic model comprised of fifteen informal zones, a vadose(unsaturated)zone and fourteen hydrogeologic units (HUs). TPH-g, TPH-d,BTEX compounds and volatile organic compounds (VOCs)were detected at all sampled HUs; the highest concentrations were detected in HU3 (50 to 65 feet bsg) and HU12 (135 to 165 feet bsg).Details of the CPT investigation can be found in the AGE-prepared Cone Penetrometer Testing Report-November 2001, dated 23 May 2003. PURPOSE In the scope of work detailed in the AGE-prepared Work Plan Addendum -February 2001, AGE proposed to advance CPT borings at four locations to a nominal depth of 100 feet below surface grade(bsg);however,during the November 2001 CPT investigation,the vertical extent of impacted ground water was greater than anticipated;sampling and analysis of ground water samples at the first two boring locations detected high concentrations ofpetroleum hydrocarbon-impacted ground water extending down to the CPT-refusal depth at approximately 180 feet bsg.Because the vertical extent of contamination appears to be much greater than anticipated, AGE decided, with San Joaquin County Environmental Health Department's (EHD) concurrence, to suspend additional CPT field work until all data could be properly evaluated and drilling modifications planned. Based on the results of the initial CPT investigation, the EHD requested, in a meeting with AGE representatives on 12 June 2003,that six CPT paired soil borings be advanced,to a maximum depth of 225 feet bsg, to help define the horizontal and vertical extent of hydrocarbon-impacted soil and ground water at the site. SCOPE OF WORK AGE proposes to advance six,paired CPT soil borings for collection of soil textural data and ground water samples to help delineate vertical as well as the lateral extent of impacted soil and ground water and define the water-bearing zones at the site. CPT paired borings will be advanced: Within the Larry's Auto compound(two pairs);inside the 825 Miner Avenue building;on Grant Street west of the site; approximately 150 feet northeast of the site; and approximately 200 feet east of the site (Figure 2). The borings will be advanced to a nominal depth of 225 feet below surface grade (bsg). One of the paired borings at each location will be a cone-penetrometer test to help determine lithology and flow units;the other,adjacent boring will be advanced to collect water samples in key water-bearing zones as interpreted from the initial CPT boring. Advanced GeoEnvironmental,Inc.