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Soil Suitability and Nitrate Loading Evaluation CTE Job # 25-0710 Great Pacific Nut—Nut Processing Facility Expansion 3501 Lehman Road Tracy, California Aufzust 1, 2019 Page 5 of 10 fine textured, nearly level soil in interfan basins. Septic tank absorption field rating for Capay soils is indicated to be "very limited" due to ponding and slow water movement. Based on published geologic mapping --"Geologic Map of the San Francisco-San Jose Quadrangle" (CDMG Map Sheet 5A, 1991) the site is indicated to be underlain by the Quaternary Alluvial Fan deposits. The percolation test holes (P-1X & P-1) encountered soil profiles of stiff medium plastic clay (CL) to maximum depth of 36 inches in test hole P-IX. Test P-1 encountered low plastic clay (CL) to 30-inches bgs and fine sandy silt (ML) from 30 to 38-inches bgs. Soils encountered with Boring- GW included stiff low plastic clay (CL) to 4 feet bgs, medium dense to dense silty sand (SM) between 4 and 20 feet bgs and stiff clayey silt (ML) from 20 feet bgs to the maximum explored depth of 25 feet bgs. The soil material type presented on the percolation test data sheets represents the soil material type present at the depth in which the percolation testing was conducted. Percolation data sheets are contained in Appendix-A. Locations of the percolation tests are shown on the attached "Exploration Location Map" (Figure-2). All test holes were backfilled to with cement grout and surface restored to original condition upon completion of testing. 7.0 PERCOLATION TESTING Our subsurface investigation included conducting leach field soil suitability evaluations via percolation testing. The evaluation included the drilling and testing of two percolation test holes at the locations shown on Figure-2. The percolati n test ere conducted at the proposed leach field location at a depth of 36-inches (P-1 ) and 38-inches (P-1).`-7 7.1 Percolation Testing Procedure I R Upon completion of the percolation test hole drilling, loose material was removed and a 3-inch diameter open-ended slotted drain pipe was installed to control potential sidewall caving of the hole. Pre-saturation of the soils to be tested was accomplished by adding water to 12-inches above the base each test hole at least 24 hours preceding the test. After the 24 hour (minimum) pre- " re- Cz1.L,INC.