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Table 2.1- Percolation Test Field Data Summary (Final 30 Minute Rate Values) Test Area Test Hole Depth Final Percolation Rate Test Duration Result (minutes/inch) 1 24"-36" 150 4hours Standard 48" — 60" 83 72" — 80" 62 2 24"-36" 40 4hours Standard 48" — 60" 120 72" — 80" 120 3 24"-36" 240 4hours Non -Standard 48" — 60" 60 72" — 80" 80 Test conducted June 16, 2022 test #1, June 23, 2022 test #2, and June 30, 2022 test #3. Proposed System Design The Project proposes to use an MBR/tertiary wastewater process to achieve unrestricted irrigation use of the wastewater plant effluent. Effluent from the wastewater plant is expected to be less than irrigation demands, thus separate effluent disposal is not anticipated. Details associated with treatment process and performance will be provide in future submittals. 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 wastewater effluent produced by the proposed project over the long term. Some of the tertiary treated effluent from landscape irrigation is expected to leach into the ground, thus ground water quality could be adversely impacted. The level of impact depends on treated effluent nitrogen concentration, rainfall that is captured and allowed to percolate, and how much nitrogen is removed by the soil/landscaping. 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 4 1 P a R e