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W. Steven Malcoun <br /> December 9, 2003 <br /> `R Page 9 <br /> 6.2 Boring Preparation and Specifications <br /> The shallow borings were advanced to 3.1 to 3.3 feet and the deep borings were drilled to 22.0 to <br /> 23.1 feet. All four borings were drilled using a truck-mounted Deep Rock auger rig on <br /> September 5, 2003. <br /> A 2-inch diameter PVC pipe with perforations on the bottom was used to measure the drop of <br /> water in the percolation test boring. Approximately 2 inches of"pea graver,were placed in the <br /> bottom of the open soil boring, then the PVC pipe was installed on top of the gravel. Several feet <br /> of"pea graver'were backfilled in the annular space. <br /> ift <br /> 6.3 Presaturation of Borings <br /> ` Presaturation of the percolation test holes occurred on September 9, 2003. The depth of water <br /> used to pre-soak was 12 inches above the bottom of the borings. After the 24-hour soak period, <br /> ` the presaturated holes were found to be intact and dry on September 10, 2003. <br /> 6.4 Percolation Test Procedure and Results <br /> A percolation test was conducted for all the borings on September 10, 2003 in accordance with <br /> the requirements of San Joaquin County EHD. A percolation test with duration of 4 hours was <br /> 6, performed. The last half hour of the 4-hour percolation tests was observed by Mr. Michael <br /> Escotto, Environmental Health Inspector, EHD. <br /> r. Measurement of the water level during the percolation test was from a fixed reference point on <br /> the PVC casing using an electric well sounder with an depth accuracy of 1/100th foot. All <br /> tabulated values on the field data sheet(appendix) are in decimal feet. After water drop was <br /> observed, the holes were checked for refill. The refill level is approximately 0.5 ft(6 inches) of <br /> water above the bottom level of the percolation test hole. The readings were taken approximately <br /> every 30-minutes for a period of 4 hours. <br /> A shallow percolation test is defined as being between 36 and 42 inches in depth. A deep <br /> percolation test is defined as being between 42 inches and 25 feet in depth. A satisfactory <br /> percolation rate for a shallow test is less than or equal to 60 minutes per inch drop. A <br /> satisfactory percolation rate for a deep test is less than or equal to 30 minutes per inch drop. <br /> Either one shallow or deep test must demonstrate a satisfactory percolation rate on each parcel <br /> ` for the percolation test requirement to be met by EHD. <br /> L <br /> 07,� <br />