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Test Results: The completed percolation test form from field measurements is included in the appendix as Exhibit C. Field data provides percolation rates for the holes tested, and provides the basis for septic system leach trench design. System design was based on the final water drop observed at the end of the four(4) hour test. Per San Joaquin County Environmental Health Department requirements,the following criteria are needed for a standard shallow disposal system: (1) percolation test holes have depths between 36 and 42 inches, acceptable percolation rates are less than or equal to 60 minutes per inch (min/in)drop,and field tests must demonstrate one(1) percolation test of acceptable percolation rate within the area of the septic system disposal field. Results of the percolation tests are summarized in the following table. Both tests indicated acceptable - percolation rates per San Joaquin County requirements. Percolation Test Field Data Summary Test Hole Depth Final Percolation Rate(minutes/inch) Test Duration Result 30"-42" 34.7 4hours Acceptable l 48"—60" 23.1 4 hours Acceptable Test conducted March 16, 2017. Proposed Septic System Design The septic system design shall be based on San Joaquin County Environmental Health Department requirements, as defined in "Onsite Wastewater Disposal Standards", 2003. Based on the results of the percolation tests, a standard septic system is proposed for the project. Section 3 Nitrate Loading Analysis Nitrate Loading Basis and Assumptions Because there are concerns of nitrate leaching into ground water from septic systems, a nitrate loading analysis is required by the SJCEHD for approval of the proposed development. The study estimates the potential concentration of percolating effluent produced by the proposed project over the long term. Where percolating effluent leaches into the ground,ground water quality may be adversely impacted to some degree,should the effluent reach ground water. The method utilized for the nitrate loading analysis is based on a simple and convenient mass balance formula, discussed in a published article by Hantzsche and Finnemore (1992). Hantzsche and Finnemore have found from investigations conducted in the Chico, California area,the water quality in the upper saturated ground-water zone closely approximates the quality of percolating effluent from septic systems.They have developed a simple method that could be used to estimate the quality of the percolating effluent from septic systems. The quality of the percolating effluent may represent the potential worst-case condition the upper aquifer would ever experience from the use of on-site septic 41