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13 August 2021 Project No. 21-6530 Page 6 of 14 Advanced utilized to advance a percolation test hole to 42 inches bsg, in the proposed septic system disposal field area. A plan of the specific site features including the percolation test hole locations (i.e., structures, drives, wells, septic systems, large trees, pastures, pools, natural drainage courses, ponds, waterways, etc.) is illustrated in Figure 2. 5.1. SOIL PROFILE PIT INCLUDING DEPTH AND DIMENSIONS The percolation test hole was located in the disposal field area of the proposed septic system. The percolation test hole was advanced to a depth of 42 inches bsg using a four - inch diameter hand auger (Figure 2). 5.2. SOIL LITHOLOGY AS RELATED TO FUTURE ONSITE SEPTIC USES The soil was visually described in accordance with the Unified Soil Classification System (USCS) by a representative of AGI under the supervision of a California Professional Geologist. The soil collected from the percolation test hole boring consisted of dry silt and clayey silt from surface grade to approximately 24 inches, sandy silt from 24 inches to 36 inches bsg, and silty sand from 36 to 42 inches bsg. The soil type is considered semi- permeable and should be sufficient for liquid waste disposal and treatment. 6.0. PERCOLATION TEST INFORMATION A percolation soil suitability test was performed at the site under EHD permit No. SR0084019 using a four -inch diameter soil boring established to a depth of 42 inches bsg. A site map showing the approximate location of the percolation test hole is illustrated in Figure 2. A precise description of the location and construction of the percolation test hole is included in Appendix C (EHD form 42-03 revised 11/02/2009). The soil suitability study was conducted within the area of the proposed septic system leach field. 6.1. NUMBER OF PERCOLATION TESTS PERFORMED One shallow percolation test was performed at the site. The appropriate percolation test procedure established by the EHD was followed for the test (Procedure #2). The percolation test hole was pre-soaked overnight for 24 hours followed by a four-hour percolation testing period.