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06 June 2003 AGE-NC Project No. 98-0468 Page 2 of 4 2.2. CPT DRILLING AND SAMPLE COLLECTION AGE proposes to advance two paired CPT soil borings at the site as part of site assessment activities. Proposed CPT soil boring locations are illustrated in Figure 2. The CPT borings will be advanced to characterize lithology, model potential contaminant migration pathways and to assess the extent of MTBE-impacted ground water. Based on the distribution of MTBE encountered to date during the ongoing investigation,AGE proposes to advance the CPT soil borings in the following locations: • Immediately north of well MW-6 and • Approximately 20 feet north of well MW-10. • AGE may request to establish additional CPT soil borings, under this scope of work, if necessary to define the lateral extent of the dissolved MTBE. The first boring at each location will be a cone penetrometer (CPT) bore; the CPT will acquire a continuous hthologic record to define the hydrologic units and pore pressure measurements. A second boring subsequently will be advanced immediately adjacent to the first bore to acquire"grab" ground water samples in targeted zones based on interpreted lithologic data and assessment needs. A minimum of four ground water samples will be collected from CPT2, located beyond the current investigation well network, and two or three grab ground water samples will be collected from CPT1, located within the current investigation boundaries. The borings will be advanced to approximately I00 feet bsg, or until grab ground water samples no longer demonstrate significant hydrocarbon impact; total depths of borings may vary according to hydrogeologic conditions encountered during drilling activities. Ground water and selected soil samples will be analyzed by a California Department of Health Services (DHS)-certified laboratory for: • Total petroleum hydrocarbons as gasoline (TPH-g) in accordance with EPA Method 8015 Modified; • Benzene, toluene, ethylbenzene and xylene(BTEX) in accordance with EPA Method 8260; and • Oxygenated fuel additive compounds di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), MTBE, tertiary-amyl methyl ether (TAME) and tertiary butanol (TBA), ethylene dibromide (EDB) and 1,2-dichloroethane (1,2-DCA) in accordance with 8260 Medif-ied, respectively. Advanced GcoEnvironmentat,Inc.