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15 July 2004 <br /> AGE-NC Project No. 98-0540 <br /> Page 4 of 10 <br /> 3.2. CPT DRILLING AND SAMPLE COLLECTION <br /> AGE proposes to advance one paired CPT soil boring at the site as part of site assessment activities. <br /> The proposed CPT soil boring location is illustrated in Figure 2. The CPT boring will be advanced <br /> to characterize lithology, model potential contaminant migration pathways and assess the vertical <br /> extent of hydrocarbons-impacted ground water. Based on the distribution of hydrocarbons <br /> encountered during the ongoing investigation, AGE proposes to advance the CPT soil boring near <br /> the former UST excavation area (see figure 2). <br /> The first of the paired borings will be a cone penetrometer (CPT) boring; the CPT will acquire a <br /> continuous lithologic record to define the hydrologic units. A second boring subsequently will be . <br /> advanced immediately adjacent to the first bore to grab ground water samples in targeted zones based <br /> on interpreted lithologic data and assessment needs. The borings will be advanced to approximately <br /> 150 feet bsg, or until grab ground water samples no longer demonstrate hydrocarbon impact;.total <br /> depths of borings may vary according to hydrogeologic conditions encountered during drilling <br /> activities. <br /> Ground water will be analyzed by a California Department of Health Services (DHS)-certified <br /> laboratory for: <br /> • Total petroleum hydrocarbons as gasoline (TPH-g) in accordance with EPA Method 8015 <br /> Modified; <br /> • Benzene, toluene, ethylbenzene and xylene (BTEX) and MTBE in accordance with EPA <br /> Method 8260; and <br /> • Oxygenated fuel additive compounds di-isopropyl ether'(DIPE), ethyl tertiary-butyl ether <br /> (ETBE), MTBE, tertiary-amyl methyl ether (TAME) and tertiary butanol (TBA), ethanol, <br /> ethylene dibromide (EDB) and 1,2-dichloroethane (1,2-DCA) in accordance with 8260 <br /> Modified, respectively. <br /> Laboratory reports for ground water analysis,testing methods, laboratory quality assurance/quality <br /> control(QA/QC) reports, and sample chain of custody documentation will be presented in a report <br /> of findings and recommendations. Procedures for CPT boring advancement and sampling are <br /> presented in Section 4.1. <br /> Advanced GeoEnvirunmental,Inc.: . . � y` <br />