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kTI KLEINFELDER soil and groundwater include fertilizer that may be used in the area, septic usage of the nearby single-family residences, and a dairy that is located approximately 2,000 to 2,500 feet to the southwest. 5. SOIL PROFILE it The subsurface conditions at the site were explored before noon on November 17, 2004, by drilling a boring to a depth of about 25 feet below existing grade. The boring was drilled using �. a Simco 2400 truck-mounted drill rig equipped with 4%2-inch O.D. solid-stem auger. The approximate location of the test boring and dimensions from a reference point are presented on the Plate 2. Based on our findings, the subsurface soils encountered in our boring consisted predominately of low- to moderately-plastic sandy silt to a depth of about 5V2 feet below the existing site •- grade. An interbedded strata of clayey sand was encountered from a depth of about 2 to 2%2 feet. The sandy silt encountered at a depth ranging from about 2%2 to 5%2 was weakly cemented. These soils were underlain by interbedded strata of moderately-plastic sandy clay, �- fine-grained clayey sand, and low- to moderately-plastic sandy silt to a depth of about 18%2 feet below the existing ground surface. These soils were underlain by fine-grained silty sand to the maximum depth explored. More detailed descriptions of the subsurface conditions encountered during our field investigation are presented on the Log of Boring, Plates 6. The Soil Survey of San Joaquin County, California published by the U.S. Department of Agriculture, Soil Conservation Service (1992) refers to the near-surface soil within the project area as belonging to the San Joaquin soil series (Map Symbols 240 and 241). These soils are described as having "severe" percolation characteristics. Other attributes are given in the table below: Map Available Water Capacity, Organic Symbol Soil Name inches/inch pH Content,percent 240 San Joaquin 0.04- 0.17 5.6- 7.8 0.5 - 1 241 San Joaquin 0.04 - 0.16 5.6 - 7.8 0.5 - 1 6. PERCOLATION TESTING Shallow and deep percolation test holes were installed in the area of the proposed leach field with the same drill rig used for the soil profile boring, only equipped with a 6-inch diameter ` auger. The approximate percolation test location is presented on Plate 2. Following drilling, the sides of the holes were scored, and significant loose material was removed from the bottom of t he h oles. T he h oles w ere d rilled a nd p repared b efore n oon o n N ovember 17, 2 004, i n accordance with SJCEHD criteria. Approximately 2 inches of fine gravel was placed at the bottom of each test hole. The tests holes were presoaked on the morning of November 18, 2004 with at least 12 inches of water. The percolation tests were started at about 10:00 AM under sunny and clear skies on November 19, 2004, in accordance with accepted guidelines 51727.G01/ST04R1700 December 17,2004 ©2004 Kleinfelder,Inc. Page 3 of 6