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February 24, 2020 BGG Job No. G 123.02 allowed to saturate overnight. Upon returning to the test hole on January 22,2020, it was observed that no water remained in the hole. Percolation testing was then performed by pouring approximately 6-to 8-inches of water into the test hole and measuring the drop in the water level over 30-minute intervals for a total period of 4 hours.The results of the percolation test are contained in Appendix A. Percolation Test Results A rate of 10.9 minutes/inch was recorded for the proposed winery septic system and leach field. SJCEHD defines a shallow percolation test hole as having a depth between 36 and 42 inches; a satisfactory percolation rate for a shallow test is one resulting in a water level drop greater than or equal to 1 minute per inch (min/in) but less than or equal to 60 min/in. For the site to utilize a standard septic system,one percolation test must demonstrate a satisfactory percolation rate within the proposed septic system disposal field. If rapid percolation occurs, a separation of 20-feet is required between the bottom elevation of the dispersal system and the ground water table;otherwise, mitigation by system design or enhancement is required, per SJCEHD. Discussion of Percolation Test Results The soils within the proposed septic system leach field area have demonstrated a satisfactory percolation rate for the use of a standard septic system in accordance with the requirements of the SJC EHD. Due to the percolation rate recorded,the SJC EHD will require a 20-foot separation from the bottom of the dispersal system to ground water(see Table 1). Ground water is anticipated to be encountered more than 50 feet bgs at the site; as such, modifications to standard septic systems should not be required. Discussion of Septic System Sizing Septic system construction utilizing leach lines should follow the San Joaquin County On-Site Wastewater Treatment Systems Standards(2017) where applicable. BAEZ GEOTECHNICAL GROUP Soil Suitability Study and Nitrate Loading Study-Zinc House Winery Page 5