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Alluvium Native alluvium was encountered at both of the boring locations extending to at least the maximum depth explored of 50* feet below existing site grade. The alluvium generally consists of medium stiff silty clays, clayey silts, and fine sandy clays extending to depths of 17* feet. Between 17 feet and 42* feet the alluvium consists of loose interbedded silty fine sands, fine sandy silts, and soft clayey silts. Medium stiff silty clays were encountered between depths of 42 to 47* feet and loose fine sandy silts were encountered at a depth between 47 feet and 50* feet. Groundwater Free water was encountered during the drilling of Boring No. B-1 at a depth of 25Â£ feet. Based on the water level measurements and the moisture contents of the recovered soil samples, the static groundwater table is considered to have existed at depths of 25* feet below existing site grades at the time of the subsurface investigation. As part of our research, we reviewed available groundwater data in order to determine the historic high groundwater level for the site. The primary reference used to determine the historic groundwater depths in this area is CGS Open File Report 97-20, the Seismic Hazard Evaluation of the Tustin Ouadranale which indicates that the historic high groundwater level for the site was 15 feet below the ground surface. More recent water level data was obtained from the California Department of Water Resources website, http://www.water.ca.gov/waterdatalibrary/. The monitoring well is located approximately 7,000 feet east-northeast from the site. Water level readings within this monitoring well indicates high groundwater levels of 25.51* feet (October 1984). Therefore, the high groundwater depth of 15 feet reported in OFR 97-20 is considered to be conservative with respect to the recent site conditions. > SOUTHERN G&M Convenience Store #72 - Santa Ana, CA CALIFORNIA Project No. 16G123-1R Page 7GEOTECHNICAL