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Project No. JB-20100 4 December 2000 Page 4 Loose, granular soils can densify and settle when subjected to seismic loading. Based on our field investigation, it is probable that seismically- induced densification of loose sandy silt deposits will occur at the site during a strong earthquake. We estimate that the settlement of such deposits will be less than one inch and differential settlements over short distances are likely to be small. 4.0 DISCUSSIONS 4.1 General The recommendations contained in this report are based on the assumption that the soil conditions encountered during construction are similar to those disclosed by our exploration. If variations are noted during construction, Korbmacher Engineering, Inc. should be notified so that we can supplement our recommendations, as applicable. Final grading plans were not available at the time of preparing this report. Based on our past experience with similar projects, site grading usually consists of 1 to 2 feet of compacted fill for preparation of the building pad and canopy pad areas. These areas are typically raised to the elevation of the existing sidewalk or the crown of the street/intersection. The fill used to raise the elevation of the site may be generated from the underground storage tank excavation. However, due to the loose near-surface soils, some over-excavation may be required in the building pad and canopy areas. Results of the subsurface site investigation indicate the existing near-surface soils are loose and could be subject to settlement. These loose soils are not the best material for support of foundations, building floor slabs, and exterior flatwork/sidewalks in their present state. Prior to foundation improvements, to help reduce the potential for adverse settlements, the soils • within the building pad area should be over-excavated and recompacted as recommended in the earthwork section of this report. Provided the earthwork recommendations are followed, it is our opinion that the proposed building may be supported on a conventional foundation system established in compacted, engineered fill. Proper drainage must be provided to prevent moisture from penetrating beneath foundations, concrete slabs-on-grade, and pavements. If moisture ' penetrates the soils beneath these areas, there could be some movement JesKork2machcr Engineering, Inc.