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KLEINFELDER EXPECT MORE 5. FIELD INVESTIGATION In order to evaluate the subsurface conditions at the project site, on May 7, 2007, two soil profile borings were drilled within the proposed leach field areas to depths of about 25 to 30 feet below existing site grade. The borings were drilled using a Simco 2400 ` truck-mounted drill rig equipped with 6-inch O.D. solid-stem auger. The approximate boring locations are presented on Plate 2. A representative with our firm maintained logs of the borings and visually classified the soils encountered according to the Unified Soil Classification System (see Plate 5). A key to the Logs of Borings is presented on Plate 6, and the Logs of Borings are presented on Plates 7 and 8. Following completion of the soil profile borings, percolation test holes P-1 through P-4 were drilled within the proposed leach field areas to depths between 3 and 9 feet below site grade. The approximate percolation test hole locations are presented on Plate 2. Following drilling, the sides of the test holes were scored, and significant loose material was removed from the bottom of the holes. The percolation test holes were then prepared by first placing about 2 inches of fine gravel at the bottom of the holes and installing a 4-inch diameter, perforated PVC pipe. Before noon on May 7, 2007, about 12 inches of water was placed in the holes for pre-soaking. On May 8, ,. 2007, the percolation tests were started at about 8:30 AM in accordance with SJCEHD accepted guidelines, using clear potable water. The holes did not exhibit sloughing or caving and were empty of water prior to testing. From a fixed reference point (a towmarked location the side of PVC pipe)the drop in water level was initially measured in approximate 30-minute intervals for 1'/� hours (SJCEHD Procedure #2) and then in approximate 10-minute intervals for 1 hour (SJCEHD Procedure #3), • refilling as necessary to maintain the prescribed amount of water over the gravel. The test procedure changed during the tests because the prescribed amount of water seeped out of the hole in less than the 30-minute interval. Under the observation of a representative from the SJCEHD, the last 10-minute readings of the tests were observed and the percolation rates, in minutes per inch, were calculated. Copies of our field percolation test results are attached on Plates 9 and 10. On May 2, 2007, samples of groundwater were obtained using clean procedures from a spigot at the head of the domestic WRU4eeated within the dealership. A permit for the well was on file with SJCEHD. The water samples obtained from the well were delivered to a laboratory on ice the same day using chain-of-custody procedures for several chemical tests including DBCP, nitrite (N) and nitrate (NO3). The boring and percolation test holes were located in the field by visual sighting and/or pacing from existing site features; therefore, the locations shown on Plate 2 should be ` considered approximate. ti 82946.GO1/ST07R401/SJW:Iv/Ir May 30,2007 ©2007 Kleinfelder Page 3 of 8