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C CORNERSTONE EARTH GROUP was observed along the western edge of the site. In general, the site is covered with low grasses and numerous low bushes. A barbed-wire fence borders the north and east site boundaries. A sound wall borders the west side of the site adjacent to the Ironwood development. A chain link fence borders the south side of the site. Numerous soil stockpiles and miscellaneous construction materials were observed across portions of the site. The approximate lateral extent of these stockpiled materials is shown on the Site Plan, Figure 2. Since the location and extent of several stockpiles appear to have changed since the site topographic data was collected, the actual lateral extent of any stockpiles should be verified in the field at the time of construction. Based on existing topographic information, site grades generally range from approximately Elevation 352 at the south end of the site to Elevation 360 feet at the northeast corner of the site (datum unknown). An existing excavation area is located near the center of the site that extends down to Elevation 347 feet, as shown on Figure 2. The site is located adjacent to an existing quarry pit that is currently referred to as Lake I of the nearby Hanson Aggregates plant. Based on our review of the slope evaluation report prepared by Geocon Consultants for Hanson Aggregates, the quarry pit is reportedly to be turned over to the Zone 7 Water Agency for future water storage, recreation and ground water recharge uses. The top of the quarry pit is located approximately 85 feet north of the site; the quarry pit slope reportedly extends down to approximately Elevation 210 feet (RJA, 2002). The quarry pit slope is inclined at roughly 1.5:1 to 2:1 (horizontal:vertical)avd is covered with sparse grasses. The future water level in the adjacent Lake I reportedly will vary between Elevation 250 and 330 feet. 3.2 SUBSURFACE CONDITIONS Boring EB-1, drilled near the northeast corner of the parcel adjacent to the existing quarry pit slope, encountered interbedded loose to dense sands and gravels to a depth of approximately 19 feet. The layer of loose sand was encountered at a depth of approximately 5 to 9 feet. The upper sands and gravels were underlain by stiff to very stiff silty clay to a depth of approximately 39'/2 feet, which was underlain by very dense clayey gravel to the maximum depth of 41'/2 feet. Borings EB-2 through EB-6 generally encountered stiff to hard sandy silt blanketing the site to depths ranging from approximately 5 to 20 feet. The near-surface silts exhibited relatively low plasticity. The near-surface soils encountered during this investigation exhibited similar plasticity characteristics. Below the upper sandy silts, Borings EB-2 through EB-6 encountered interbedded layers of loose to medium dense sand, silty sand and sandy gravel and stiff to very stiff silty clay and clayey silt to a depth of 29'h feet, the maximum depth explored in Borings EB- 2 through EB-5. The loose sand layers encountered generally ranged from 1 to 4 feet thick. We also reviewed the subsurface conditions encountered in Boring GB-4 performed by Geocon Consultants for the adjacent quarry slope. Boring GB-4 was located approximately 60 feet north of the site adjacent to the top of the quarry slope. Boring GB-4 encountered approximately 6 feet of sandy clay fill underlain by approximately 10 feet of medium dense gravel. The upper gravel was underlain by very stiff clay to a depth of approximately 44 feet, which was underlain Ponderosa Active Adult Community Page 4 132-2-1