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ENGEO INCORPORATED 5150.100.101 May 2, 2008 Page 12 As used in this report, the term “moisture condition” refers to adjusting the moisture content of the soil by either drying if too wet or adding water if too dry. We define “structural areas” in Section 4 of this report as any area sensitive to settlement of compacted soil. These areas include, but are not limited to building pads, sidewalks, pavement areas, and retaining walls. 6.1 EXPANSIVE SOIL MITIGATION Any potentially expansive clay encountered within building pads should be removed to a depth of at least 3 feet below pad grade, as determined by an ENGEO representative. Because the site will have extensive cutting of the native material, any expansive material that is encountered should be removed from the site during cut and fill operations. In addition, no potentially expansive clay should be placed within the upper 3 feet of building pads. 6.2 BUILDING PAD PREPARATION Because of the depth of cut across the site and the presence of colluvial deposits in one half of the building footprint, there is a possibility of encountering soil on one side of the building pad and rock on the other. To reduce the risk of differential settlement due to the relative stiffness difference between these materials, we recommend that the building pad be overexcavated and backfilled with acceptable compacted fill. In building pads, and extending laterally a minimum of 5 feet beyond, the foundation soil should be overexcavated a minimum of 2 feet and the excavation should be backfilled with properly compacted, processed fill. Fill material type and compaction should meet the requirements of this report.