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KLEINFELDER 21, 2004. The holes were drilled and prepared approximately between 8:00 and 10:00 am on May 20, 2004 in accordance with SJCEHD criteria. The preparation procedure calls for first placing about 2 inches of fine gravel at the bottom of each borehole and then presoaking them with a minimum of 12 inches of water at least 24 hours prior to performing the test. The hole was originally presoaked on May 20, 2004 soon after drilling. The percolation tests were started at approximately 8:00 am under sunny and warm weather on May 21, 2004, in accordance with accepted guidelines using clear potable water. The approximate depth of each percolation test hole below existing site grade is shown on the following table. The holes had scored sides and _. no significant loose material at the bottom. No standing water from presoaking remained in either test hole at the time of testing. From a fixed reference point, a marked location on the side of PVC pipe inserted into the hole, the drop in water level was measured in approximately 30- minute intervals for four hours, refilling as necessary to maintain the prescribed amount of water over the gravel (SJCEHD Procedure #2). Under the observation of a representative from the SJCEHD, the last 30-minute reading of the four-hour period was recorded and used to calculate the percolation rate in minutes per inch. The estimated percolation rates are summarized below. Test Location Performed Depth (feet) Percolation Rate (min./inch) Number P-1 3.4 125.0 10.0 62.5 In accordance with SJCEHD criteria, a suitable soil condition for percolation tests from about 3 to 3'/z feet in depth is defined as a stratum capable of percolating water at a rate of 60 min/inch or faster. For tests deeper than about 3% feet a suitable soil condition is defined as a stratum capable of percolating water at a rate of 30 min/inch or faster. Neither of the percolation tests at location P-1 met these minimum requirements. On May 26, 2004, our drill rig returned to the site, and two 6-inch diameter percolation holes were drilled adjacent to the existing sump. The soil encountered in these additional percolation test holes consisted predominately of sandy clay. These soils, however, contained relatively thin interbedded seams of silty sand. The approximate test location and approximate dimensions _y from a reference point are presented on the attached plate. Similar to our previously installed percolation test holes, the location of our percolation test holes were based on dimensions shown on the installation permit for the system dated November 21, 2004. The holes were drilled and prepared approximately between 8:00 and 9:00 am in accordance with SJCEHD criteria as described above. The holes were presoaked on May 26, 2004 soon after drilling. The percolation tests were started at approximately 9:00 am under sunny and warm weather on May ,y 27, 2004, in accordance with accepted guidelines using clear potable water. The approximate depth of each percolation test hole is shown on the following table. The holes had scored sides and no significant loose material at the bottom. No standing water from presoaking remained in either test hole at the time of testing. From a fixed reference point, a marked location on the side of PVC pipe inserted into the hole, the drop in water level was measured in approximately 30- minute intervals for four hours, refilling as necessary to maintain the prescribed amount of water -�- over the gravel (SJCEHD Procedure #2). Under the observation of a representative from the 44973.G01/ST04R872 June 23,2004 ©2004 Kleinfelder,Inc. Page 4 of 6