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Mr. George Rose April 12,2001 Page 2 Generally,the three(3)borings composed of similar materials which consisted of sandy soils with a'matrix of silt or clay. Between the depths of 14 feet to 17 feet, a clean sndy stratum was encountered , (Plates 2-5). The thickness of the sand was found to be greater than two(2),f cet at,each location. This sandy zone was the first sufficiently permeable soil layer encountered during drilling and'was selected for the percolation test. The soils encountered during the drilling of the three holes were very typical of soil conditions encountered at other locations of the site. Percolation Tests For new Parcels.1, 2, and 3, a,percolation test was performed to demonstrate the capacity for soil percolation for use with an on-site septic system.The depth of the test was determined by setting the casing adjac6nt.to the first sufficiently permeable material encountered(usually sandy soil) found to a iriaximurn depth of 25-feet: The casing used for the test was a.2-inch diameter,PVC pipe'with an open end on.the top and bottom: Perforations were placed'on the bottom 1 foot of the pipe. Two(2) inches of"pea gravel"was placed in the bottom of the holed the casing was installed, and one(1)foot of"pea gravel"was backfilled in the annular space. - A one(1)hour percolation test conducted on April 5, 2001 in accordance with the requirements of ,San Joaquin County Environmental Health Division. The placement of the test was in a location that could be used for a future septic system. The percolation test of the three(3)parcels was observed by Mr.Rodney. Estrada, Senior registered Environmental Health Specialist, San Joaquin County"Environmental Health Division. An electric well sounder was used to measure the water drop over an minimum interval of 10 minutes for the April 5, 2001 test. The units of the sounder are in feet with a 11100 foot resolution. To convert to inches,the value on the field sheet was multiplied by 12.' The percolation test was conducted for A period of one hour. A satisfactory percolation 'rate was measured for each of the three(3)parcels. Table 1 presents a summary of percolation test information relatiing to the new lot line adjustments. Summary of Percolation Tests... Relating to Lot Line Adjustment(LA-01-04). Parcel Number Boring Number, Percolation Rate Depth of Test Date of Test New Parcel 1 23 0.75 min/inch 18 feet April 5,2001 New Parcel 2 24 1.54 min/inch 17-feet 'April 5,2001 New Parcel 3 25 1,67 min/inch 15 feet April 5,2001 New Parcel 4 16 . 30 min/inch 3 feet October 6,2000 New Parcel 5 NA NA NA NA New Parcel 6 14 l0 min/inch 21 feet October NA:Not applicable,the testing of new Parcel 5 was not required. rocRsc " a 4