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28 September 2022 Project No. 22-6994 Page 7 of 15 AdvancedGeo An Employee- Owned Company �w• 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 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 borings consisted of dry, sandy silty to sandy clay from surface grade to approximately 30 inches bsg; cemented clayey sand from 30 inches to 80 inches bsg; and sandy clay and silty sand from 80 inches to total depth. The soil type is considered semi -permeable and should be sufficient for liquid waste disposal and treatment. 6.0. PERCOLATION TEST INFORMATION Percolation soil suitability tests were performed at the site under EHD permit No. SR0085730 using four -inch diameter soil borings established to depths of 40 and 118 inches bsg. A site map showing the approximate location of the percolation test holes is illustrated in Figure 2. A precise description of the location and construction of the percolation test holes are included in Appendix D (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 Two percolation tests were performed at the site. A shallow percolation test was performed at 40 inches bsg (P-1) and a deeper test was performed at 118 inches bsg (P-2). The appropriate percolation test procedure established by the EHD was followed for each test. Percolation test Procedure #2 was used for the shallow test. The percolation test hole was pre-soaked overnight for 24 hours followed by a four-hour percolation testing period. Percolation test Procedure #3 was used for the deep test. The percolation test hole was pre-soaked overnight for 24 hours followed by a 1.5 -hour percolation testing period. 6.2. CONSTRUCTION OF PERCOLATION TEST HOLE On 14 September 2022, one boring was advanced for a shallow percolation test. The boring was advanced using a four -inch diameter hand auger to a depth of 40 inches bsg. Following borehole advancement, the sides of the boring were scraped, and loose material was removed from the borehole. Once the borehole was cleared of loose