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Soil Suitability&Nitrate Loading Evaluation CTE Job#25-1256G New Septic Leech Lines 9490 E Schmeidt Rd Lodi, California June 29, 2022 Page 6 of 10 above the base each test hole the day preceding the test. Percolation testing was performed the following day. After the 24-hr pre-saturation period a 6-inches column of water was added to (P-1) above the top of the 2 inches of clean coarse sand placed at the base of the test hole. Recordings were made of the change (drop) in water level at regular 30-minute time intervals for four hours. Water level was refilled to 6 inches above the clean coarse sand after each interval. The smallest reading of the four-hour period was used to calculate percolation rate. Specific details are included on the attached percolation test data sheets located in Appendix-A. 8.2 Percolation and Infiltration Rates The soil percolation rate is defined by the average time in minutes for a 1-inch column of water to "seep" into the soil. Percolation rate was calculated in minutes per inch (MPI) by dividing the time (in minutes) by the change (drop) in water level (in inches). No correction factor was used in the calculation for the 4-inch boring diameter. Percolation test "P-1" achieved a generally steady percolation rate of 20 minutes/inch at 36-inches begs. The percolation rate obtained from testing is moderate and consistent with the above USDA soil survey descriptions. Based on our experience these soils and corresponding percolation rates are not inconsistent with those typical of the soil types encountered in the vicinity. Owing to variations in material type and depth, percolation rates would typically be expected to fluctuate somewhat across a site and are also dependent upon actual construction, depth, size, location, and workmanship of the drainage element. Based on percolation test results, the soil in the upper 42-inches of the site are moderate permeable (percolation rate between 5min/inch and 30 min/inch) and are considered suitable for a conventional septic tank/leach trench disposal systems. 9.0 NITRATE LOADING CALCULATIONS Per SJEHD requirements, the following summarizes our nitrate loading calculations for the proposed leach field. The state drinking water standard for nitrate is 45 milligrams per liter (NO3) %TC ,INC