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`.J KLEINFELDER r 6. PERCOLATION TESTING The 6-inch diameter percolation holes were drilled with the same equipment as the soil profile boring. Eleven percolation holes were drilled on the subject property. The holes had scored (G•y� r sides and no significant loose material in the bottom of the hole. The holes at location P-1 were drilled and prepared before 9:00 am on October 16, 2003. The holes at location P-2 were drilled and prepared before 10:00 am on October 20, 2003. The holes at location P-3 were drilled and prepared before 7:30 am on October 30, 2003. All of the test holes were drilled and prepared in accordance with SJCEHD criteria. The preparation procedure calls for first placing about 2 inches of fine gravel at the bottom of the borehole. The hole is then pre-soaked with a minimum ►. of 12 inches of water at least 24 hours prior to performing the test. The percolation tests were started at 12:00 noon at location P-1 on October 21, 2003. Due to a shortage of available inspectors, SJCEHD could not inspect the percolation tests at location P-2 on October 21, 2003, so the tests were performed on October 22. These holes were again presoaked on October 21. The percolation tests were started at 7:30 am at location P-3 on October 31, 2003. All of the tests were performed under sunny and warm weather and in accordance with accepted guidelines using clear potable water. The approximate depth of each percolation test below existing site grade is shown on the following table. None of the holes exhibited sloughing or caving after presoaking except for the shallow hole at location P-2. This hole was originally about 3.3 feet in��•'� depth. The holes were dry prior to testing. From a fixed reference point, a marked location on the side of PVC pipe inserted into the hole, the drop in water level is 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 is recorded and used to calculate the percolation rate in minutes per inch. The estimated percolation rates are summarized below. ` A copy of our field percolation test results signed by a representative from SJCEHD is attached. Details of each test can be found on the percolation test sheet. Due to a barely legible faxed copy(L,L) of the site map, the location of P-1 was originally given as about 700 feet north of McAllen Road. Upon review of a better copy of the map, this distance has been revised to about 900 feet north of the road. Test Number Depth (feet) Percolation Rate(min./inch) P-1 15.7 31 f- 4.4 125 4 Did not finish, slow percolation 4 Did not finish, slow percolation - P-2 2 83 11.9 6 P 21.7 18 P P-3 3.5 Did not finish, slow percolation ' 12.1 8 bw 36012.G01/ST03R1749 November 20,2003 ©2003 Kleinfelder,Inc. Page 4 of 5 L