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Percolation Test Irerracon <br /> Pickens Residence ■ Tracy, California <br /> August 14, 2018 ■ Terracon Project No. NA181172 <br /> advanced using a 4-inch diameter hand auger. The following table presents a log of the soil <br /> borings. <br /> Table 1 <br /> Summary of Soil Lithology <br /> Depth <br /> Unified Soil <br /> Boring Interval Soil Type <br /> Classification <br /> (ft) <br /> 0- 1.8 Trace clay, high dry strength, high toughness, dark brown dry SW-SC <br /> Trace calcareous nodules, nonplastic, low dry strength, low <br /> 133.5 toughness, tannish brown, silty fine sand to a fine sandy silt with <br /> 1.8-3.5 SW-SC <br /> clay. Soils at 3.5 feet are somewhat tight silty fine sand with <br /> traces of clay <br /> 0- 1.8 Trace clay, high dry strength, high toughness, dark brown dry SW-SC <br /> B10 Trace calcareous nodules, nonplastic, low dry strength, tannish <br /> 1.8- 10.0 SW-SC <br /> brown, silty fine sand to a fine sandy silt with clay. <br /> The shallow boring (B3.5) was additionally prepared for a percolation test per the San Joaquin <br /> County EHD Percolation Test Procedure dated 2011. Approximately two inches of "pea gravel" <br /> was placed in the bottom of the open boring. A 2.0-inch diameter PVC pipe with perforations <br /> towards the bottom was installed on top of the gravel and the boring was presaturated with <br /> approximately 12 inches of water over gravel. <br /> August 9, 2018, the shallow boring (B3.5) was found to be dry and intact on the day of the <br /> percolation test. Approximately 0.5 feet of water was added over gravel and the drop in water <br /> level was recorded every 30 minutes over a four hour period. The final 30 minutes of the test <br /> was observed by EHD representative Ms. Betty Ho who signed the percolation test form. <br /> Table 2 <br /> Summary of Percolation Test <br /> Test No., Date Percolation Test Percolation Rate Test Duration Comments <br /> Tested Depth (feet) (min/in) (hours) (see note) <br /> 133.5—8/8/18 3.5 5 4 Satisfactory <br /> Percolation Rate <br /> Note: A satisfactory percolation rate is 60 minutes per inch or less for shallow leach lines and 30 minutes per inch or less for <br /> septic pits per San Joaquin County Onsite Wastewater Treatment Systems Standards(EHD 42-014),January 2017. <br /> Based on the percolation test results, the shallow soils within the proposed sewage disposal <br /> area have demonstrated a satisfactory percolation rate (5 minutes/inch) in accordance with San <br /> Joaquin County requirements for the use of a standard septic system. <br /> Responsive■ Resourceful ■ Reliable 2 <br />