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�✓ ,../ 19 July 2005 AGE-NC Project No. 95-0135 Page 5 of 9 drill rig equipped with 8.25-inch hollow-stem augers. The total depth of each well boring may vary according to geologic/hydrogeologic conditions encountered during drilling.Proposed locations of the pilot soil borings, illustrated on Figure 2, are as follows: • On-site drilling(Phase 1):Two borings(1,2)will be advanced immediately southwest of the former dispenser island to depths of 65 feet bsg (HU2) and 120 feet bsg (HU3); _� NO sa: 1 UJ • One boring (3) will be advanced immediately south of the former waste oil UST (T4)to a S` depth of 65 feet bsg (HU2); • One boring (4) will be advanced near the midpoint between MW-1 and MW-2 to a total depth of approximately 120 feet bsg (HU3); and No so; j �p1 ri • Off-site drilling(Phase 2): Three borings (5, 6, 7)will be advanced across Lafayette Street near CPT-3 to total depths of approximately 45 feet(HU1), 65 feet(HU2) and 120 feet bsg (HU3). No ` Selected soil samples will be analyzed by a State of California Department of Health Services (DHS)-certified laboratory for the following constituents: • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015 Modified; and • Benzene, toluene, ethylbenzene and xylenes (BTEX); and fuel additives methyl tertiary- butyl-ether(MTBE),tertiary butyl alcohol(TBA),di-isopropyl ether(DIPE),ethyl tertiary- butyl ether(ETBE),tertiary-amyl methyl ether(TAME), 1,2-dibromoethane(EDB),and 1,2- "' dichloroethane (1,2-DCA) in accordance with EPA Method 8260B. Laboratory reports of soil and ground water analysis, testing methods, laboratory quality assurance/quality control (QA/QC) reports, and sample chain of custody documentation will be presented in a report of findings and recommendations. 3.3. MONITORING WELL INSTALLATION, DEVELOPMENT, AND SURVEY r The seven pilot soil borings will be completed as single-level ground water monitoring wells screened from 25 feet to 45 feet bsg, 60 feet to 65 feet bsg, or 110 feet to 120 feet bsg. Following installation, each well will be developed to maximize water flow and minimize the amount of fine-grained sediment drawn into the well during pumping or bailing. The top of the existing and newly installed well casings (well heads) will be surveyed to determine their elevation relative to mean sea level. Advanced GeoEnvironmental,Inc.