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Soil Suitability/ Nitrate Loading Study Irerracon Shipherd Property■ Ripon, California August 25, 2020 -k Terracon Project No. NA207060 Based on a review of the boring log, the well was advanced to 30 feet bgs and consisted of silty sand in the upper five feet, silt at 10, 15, and 20 feet, silty sand at approximately 23 feet bgs, and poorly graded sand between 27 and 30 feet bgs. Groundwater was reportedly encountered at approximately 24 feet bgs. 1.6 Percolation Test Information 1.6.1 Percolation Test Locations Refer to Section 1.5.1 and Appendix A, Exhibit 2. 1.6.2 Number of Percolation Tests Two percolation tests (B1 and B2) were performed. 1.6.3 Boring Preparation and Presaturation The percolation test borings (B1 and B2) and soil profile (B3) were hand augered on July 30, 2020. Approximately two inches of"pea gravel"was placed in the bottom of the open borings. A 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 holes occurred the same day approximately 24 hours prior to the day of testing. The depth of water used to pre-soak the shallow borings was approximately 1.0 foot above the top of the gravel. 1.6.4 Condition of Borings after Presaturation Borings B1 and B2 were dry and intact after the 24-hour pre-soak period. 1.6.5 Percolation Test Procedure On July 31, 2020, the percolation test was conducted at boring B2 in accordance with the requirements of the San Joaquin County Percolation Test Procedure (Form: EHD 42-01-002 Revised 08-23-2011). There was no water remaining in the test hole and 0.5 feet of water drained from the test hole within the first 30 minutes of the test; therefore, Terracon conducted the percolation tests by following Procedure #3. Terracon added clear water approximately 0.5 feet above the top of the gravel and recorded the drop in water level in one to two-minute intervals over a one-hour period. 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 are in decimal feet. The percolation test was observed by Ms. Sukhreet Kaur of the EHD; however, Ms. Kaur did not sign the percolation test rate form due to questions regarding the fast percolation rate. Responsive ■ Resourceful w Reliable 10