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lierracon Soil Suitability / Nitrate Loading Study Azevedo Property Acampo, CA June 19, 2019 Terracon Project No. NA197009 1.6.5 Percolation Test Procedure On April 18, 2019, the percolation tests were conducted 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 holes; therefore, Terracon conducted the percolation tests by following Procedure #2. Terracon added clear water approximately 0.5 feet above the top of the gravel and recorded the drop in water level at thirty minute intervals over a four 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 tests were observed by Mr. Naseem Ahmed, EHD representative. 1.6.6 Percolation Test Forms and Results 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 shallow percolation test must demonstrate a satisfactory percolation rate of less than or equal to 60 minutes per inch drop in water level within the existing septic system disposal field of a parcel to utilize a standard septic system and 30 minutes per inch or less for septic pits. Details of the percolation tests are summarized in the table below. Table 7. Summary of Percolation Tests. Test No. Date Tested Percolation Test Depth (feet) Percolation Rate (minutes/inch) Test Duration (see notes) Comments B1 03/22/2019 3.5 50 4 hours Satisfactory Percolation Rate B2 03/22/2019 3.9 83.33 4 hours Unsatisfactory Percolation Rate Note: A satisfactory percolation rate is 60 minutes per inch or less for shallow leach lines and 30 min tes per inch or less for septic P # pits per SJEHD, Onsite Wastewater Disposal Standards, October 2003. \ 1t The completed percolation test form with Mr. Ahmed's verification signature is included in Appendix E of this report. 1.6.7 Discussion of Percolation Test Results Based on the Percolation tests results, Boring B1 at 3.5 feet bgs achieved a passing percolation rate of 60 minutes per inch or less for standard leachfields. Boring B2 at 3.9 feet bgs failed to have a passing percolation rate. Responsive Resourceful a Reliable 11