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ACI-P-97-1006 Ranch Market - Phase 11 Page 4 4 The site is situated in the northeastern portion of the San Joaquin Valley, in the southern Great Valley physiographic province. The Great Valley is an elongate northwest trending asymmetric structural basin that has a wide flank and a narrow western flank expressed by the upturned edge of the sediments that have accumulated in the basin The San Joaquin Valley is filled with a thick sequence of marine and continental sediments ranging in age from Jurassic to Recent. The thickest accumulation underlying the western portion of the valley The Sierra Nevada Range is the pritnary source for this sequence of sedimentary rocks The youngest limit beneath the site are mapped as Quaternary (Recent) alluvial fan deposits of the Modesto Formation on the Geologic Map of the San Jose Quadrangle 1981 (1.75,000) S Q • During the drilling, groundwater was first encountered in fine, well sorted uniform sand and silty sand at a depth of 29 6 fleet below grade. Flow the primary surface drainage is in the immediate area of Staiuslaus River, located approximately 750 feet south of the site Surface drainage at the site is to the southwest G The site stratigraphy is characterized by alternating horizons of sand, silty sand and clay down to the water table A stiff, dense clay layer was found at the 15-17 foot depth The boring log is presented in Figure 4. 7 SQ[L AND GRI21TNDWATER ANALVS-- Three soil samples and one groundwater sample was analyzed for TPHg and BTEX The water sample and the highest TPH soil sample were tested for the oxygenates compounds All analyses were conducted by Sherwood Labs, a state certified laboratory located in Hilmar, California Sample identities and analytical results for each constituent detected are presented in Tables 1 and Table 1. Certified analytical reports and completed Cham-of-Custody documents are 10 presented in Appendix B I and B 1.