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• time of our site visits. We did not observe any apparent damage to the drainage channel as a result of the <br />slope failure. <br />The vegetation in the slope failure area was spazse due to the previous site grading operations. However <br />the vegetation along the undisturbed slope situated to the east of the failed area ,is heavily vegetated with <br />weeds, grasses, deciduous shrubs and scrub oaks. <br />Generally the site slopes moderately to steeply down to the southwest towazds Pond 12. The topography in <br />the failure area is highly variable due to the previous site grading, pond construction, slope movement and <br />debris flows. Based on our review of the topographical maps, provided by the client, for the area prior to <br />the development, it appears that the natural slopes in this azea were also highly variable and ranged from 15 <br />to 25 percent in the lower portion of the failure area/debris flow; whereas the upper portion of the slide <br />azea ranged from 25 to 40 percent. It also appears that the azea located uphill of the slide area and head <br />scarp was on the order of 50 to 65 percent. <br />Field Investigation <br />The field investigation for this project was conducted from June 19 to July 2, 2008. Eight (8) test holes <br />were advanced within the failure area. In addition, five (5) test pits were excavated within the slide area <br />with a trackhoe. Due to the steepness of the slope located above the head scarp we were unable to access <br />this portion of the site with the drill rig.The test hole and test pit locations aze shown in Figure #2. <br />The test holes and pits were advanced to explore the subsurface conditions within the limits of the failed <br />area. Locations of the test holes and test pits were determined in the field by a representative of NWCC, <br />Inc. and surveyed by the client. The elevations of the test holes were provided by the client after the <br />instrument survey was completed. <br />The test holes were advanced through the existing fill materials, overburden soils and underlying bedrock <br />materials with 4-inch diameter continuous flight power augers using atrack-mounted CME 55 drill rig. <br />The test pits were advanced with a trackhoe to better define the condition of the fill materials. A <br />representative of NWCC, INC logged the test holes. Four (4) of the test holes were also cased with slotted <br />and solid 2-inch diameter PVC pipe so that groundwater levels and soil movements could be monitored <br />after the drilling was completed. <br />Sarnples of the subsurface materials were taken with either a 2-inch I.D. California liner sampler or a split <br />spoon sampler. The samplers were driven into the various strata with blows from a 140-pound hammer <br />• falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D 153- <br />Job Number: 07-7600 NWCC, Inc. Page 3 <br />