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Soil Suitability/Nitrate Loading Study 1�erracon Avanti Nut Co. ■ Stockton, CA May 19, 2016 ■Terracon Project No. NA167038 1 1.6.2 Number of Percolation Tests Two percolation tests (P1) in the area of the proposed septic leach field, at 3.5 feet bgs (P1) and 21.0 feet bgs (P2), were conducted for soil characterization to aid in the septic system design. 1.6.3 Boring Preparation and Presaturation The soil borings were excavated on May 5, 2016. Approximately two (2) inches of "pea gravel" was placed in the bottom of each open hole. At each hole, 2.0-inch diameter PVC pipe with perforations towards the bottom was installed on top of the gravel and the annular space was backfilled with "pea gravel". Presaturation of the percolation test hole occurred approximately 24 hours prior to the day of testing (May 6, 2016). The depth of water used to pre-soak was 24 inches above the bottom of each boring. ' 1.6.4 Condition of Borings after Presaturation After the 24-hour soak period, both holes were found to be intact however, the shallow hole still contained water from the presaturation and the deep hole was dry on the day of testing (May 6, 2016). 1.6.5 Percolation Test Procedure The percolation test was conducted on May 6, 2016 in accordance with the requirements of the San Joaquin County EHD. The percolation test had a duration of 4 hours. The last thirty minutes 1 of the test was observed by Ted Tasiopoulos, Registered Environmental Health Specialist (RENS), EHD. Measurement of the water level during the percolation test was from a fixed reference point on the PVC casing using a calibrated Solinst electric water level detector with a depth accuracy of 0.01 feet. All tabulated values on the field data sheet (Appendix C) are in decimal feet. After water drop was observed, the hole was checked and refilled as necessary to maintain approximately 0.5 feet (6 inches)of water above the bottom level. The readings were taken every thirty minutes for a period of 4 hours. 1.6.6 Percolation Test Forms and Results The completed percolation test form with Ted Tasiopoulos's REHS verification signature is included in Appendix C of this report. A shallow percolation test is defined by the EHD as being between 36 and 42 inches in depth. While a deep percolation test is defined by the EHD as being between 42 inches and 25 feet in depth.. The percolation test must demonstrate a satisfactory percolation rate (less than or equal to 60 minutes per inch drop) within the existing septic system disposal field of a parcel to utilize a standard septic system. Details of the percolation tests are summarized in the table below. Responsive u Resourceful u Reliable 8 1