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19 November 2009 AGE-NC Project No. 02-0950 Page 6 of 13 ground water flow directions and gradients from October 2003 to May 2009 are presented in Appendix E. Based on quarterly ground water monitoring results between October 2003 to May 2009, TPH-g, TPH-d and BTEX have been established as the contaminants of concern at the site. Laboratory analysis of ground water samples historically detected TPH-g and TPH-d from monitoring wells MW-2 and MW-7 at concentrations as great as 89,000 µg/1 and 88,000 gg/l, respectively. BTEX compounds were also detected from the same wells at concentrations as high as 600 µg/l benzene, 9,200µg/1 toluene,3,800µg/1 ethylbenzene and 18,600µg/1 xylenes.Additionally,tert-amyl methyl ether(TAME)was sporadically detected from wells MW-2 and MW-7 at concentrations as high as 26 gg/l, while 1,2-dichloroethane (1,2-DCA) was sporadically detected from well MW-2 at concentrations as high as 8.1 gg/l. Ground water analytical data is summarized in Table 6. j Based on plots of TPH-g, TPH-d and benzene versus time (Appendix F), a definitive trend of decreasing dissolved concentrations has been evident at the site from monitoring wells MW-2 and MW-7.Additionally,at various monitoring events after June 2007,wells MW-2 and MW-7 declined to non detect levels for TPH-d and BTEX constituents,while TPH-g concentrations declined to 520 µg/1 and 300 µg/1, respectively. 2.5. STRATIGRAPHY In general, the soil profile consists of fine stiff to hard, sandy silt,.silt and clayey silt from a depth of 5 feet bsg to 20 feet bsg.A medium dense to dense,fine to coarse sand with varying percentages of silt was typically encountered at depths of 25 feet and 30 feet bsg in a majority of the borings; however, this soil type was only encountered at 25 feet bsg in several of the borings. At depths between 30 feet and 45 feet bsg, a stiff to hard,fine-grained silt and lean clay were encountered. A poorly graded fine sand with silt was encountered at a depth of 50 feet bsg. Soil boring and well completion logs are presented in Appendix C.Cross sections D-D'and E-E'depict general lithology beneath the site (Figures 4 and 5, respectively). 3.0. SENSITIVE RECEPTOR SURVEY As a result of this California CCR requirement,a sensitive receptor survey was performed at the site. The sensitive receptor survey consisted of identifying septic systems and municipal, domestic, irrigation or ground water monitoring wells within a 2,000 foot radius of the site.The location of the site and the immediately surrounding area are illustrated in Figure 1. Site structures are depicted in Figure 2. Advanced GeoEnvironmental,Inc. r