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16 October 2006 AGE-NC Project No. 98-0520 Page 3 of 10. MW-5. Figure 4 illustrates the approximate distribution of dissolved TPH-g. Toluene was reported in the sample collected from well MW-3 at aconcentration of 2.1 µg11. Ethyl- benzene was reported in the samples collected from wells MW-3 and MW-5 at concentrations of 14µg/l and 860 µg/l,respectively.The m,p-Xylene was reported in the samples collected from wells MW-3 and MW-5 at concentrations of 2.0 µg/l and 360 µg11, respectively. ' No additional target analytes were detected at or above laboratory reporting limits in the ground water samples collected.Analytical results of ground water samples are summarized in Table 2.The laboratory report(CTEL Project No. CT214-0606084),quality assurance/quality control (QA/QC) report,and chain of custody forms are included in Appendix C. Documents confirming the upload of laboratory electronic deliverable format (EDF) files and depth to water measurements to ' GeoTracker are included in Appendix D. ' 3.3. FATE AND TRANSPORT MODELING The Waterloo Hydrogeologic RISC WorkBench 4.0 program (RISC WorkBench) was used to perform fate and transport modeling and additional human risk assessment. Based upon historical depth to ground water measurements from the site, depth to ground water has ranged from approximately 17 to 25 feet bsg at the site. Deep soil, as defined by the San Francisco Bay Regional Water Quality Control Board (SFBRWQCB)as greater than 3 meters bsg, at the site�has had reported detections of hydrocarbons ' above the SFBRWQCB's commercial (and residential) Environmental Screening Level (ESL) for TPH-g,ethyl-benzene and total xylenes.The maximum concentration of TPH-g,ethyl-benzene and total xylenes in deep soil was 670 milligrams per kilog (mg/kg), 10 mg/kg and 13 mg/kg, ' respectively. Toluene was reported at detectable levels, b t below ESL. Benzene, TBA, MTBE, 1,2 DCA and EDB were not reported in deep soil above detectable levels. Table 4 provides a ' comparison of the SFBRWQCB ESLs to the maximum concentrations of hydrocarbon-impacted soil samples collected at the site. Appendix A includes a table of historical soil samples collected at the site. ' The average hydrocarbon-impacted ground water samples collected at the site during the last 8 quarters of monitoring for all listed SFBRWQCB ESL constituents of concern were under the ESL ' when ground water is a potential, source of drinking water with the exception of TPH-g,' ethyl-benzene and total xylenes. The average concentration of TPH-g for the last 8 quarters at the site was reported to be 1,986 pg/l, which is above the ESL of 200 µg/l. Table 4 provides a ' comparison of the SFBRWQCB ESLs for both ground water as a potential source of drinking water and ground not as potential source of drinking water to the average concentrations of Advanced GeoEnvironmental,Inc.