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Patterson Pass Business Center, Building#6 Page 7 Tracy, California The site is located within Seismic Zone 3 per the seismic zone map in the current edition of the UBC. The UBC specifies a basic seismic design factor based on an Effective Peak Ground Acceleration of 0.30g. Estimated earthquake ground motions at the site for the maximum probable earthquake (MPE) with a 10 percent probability of being exceeded during a 50-year period (475- year event) have been estimated in order to determine the Probable Maximum Loss (PML). The values of PGA have been estimated using the United States Geological Survey (USGS) National Earthquake Hazard Mapping Project data, California Geologic Survey data, and the Seismic Safety Element of the Tracy General Plan. According to the above data and the Seismic Safety Element, the Peak Ground Acceleration (PGA) at the site associated with the 475-year earthquake is estimated to be 0.45g, which corresponds to an Effective Peak Ground Acceleration of approximately 0.33g and MMI VIII. The above data indicates that UBC code-level earthquake ground motion for Zone 3 to be used in the design of new buildings is approximately the same as the future MPE ground motion expected at the site. Fault Rupture Hazard The site is not located within a California Fault-Rupture Hazard Zone. The nearest fault to the site is the potentially active Tracy-Stockton fault, approximately six miles northeast of the site. Since no active or potentially active faults are mapped in the vicinity of the site, the potential for ground surface rupture due to recognized faulting is considered to be low. Soil and other Earthquake Hazards The soils underlying the site consist of silty clays and sandy clays. Ground water is at depths ranging from 16 to 23 feet below the surface. Due to the presence of clays, the dense nature of the sands, the depth to groundwater, and the relatively low level of anticipated ground shaking, the liquefaction potential at the site is low. The potential for earthquake-induced landslide or slope stability failure is low as there are no slopes on or near the site. The site is not adjacent to a large body of water, and is therefore not susceptible to earthquake-induced seiches or tsunamis. Therefore, the earthquake-related flooding potential at the site is low. 05005.01 R. D. Boyens Engineering