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Percolation Testing <br /> Percolation testing was conducted by Keir&Wright on July 8th, 2022 beginning at 10:00 AM. Percolation <br /> tests were performed at three (3) depths in one (1) location on the Site. A soil mantle pit of 10' depth <br /> was opened using a backhoe. No standing water was observed. <br /> Percolation test procedures conformed to the San Joaquin County Environmental Health Department <br /> requirements, as discussed herein. <br /> Test Preparation: Shelves were cut at 24 inches, 48 inches, and 60 inches. In each shelf, a 12"x 6" <br /> diameter hole was prepared and 2" of gravel was added to the bottom of each hole. Soil removed from <br /> the hole was examined and logged. Reference boards were installed level and above the test holes. The <br /> test holes were saturated approximately 24 hours prior to beginning the test. <br /> Test Procedure: A four(4) hour test was performed for each hole. Water level measurements were <br /> taken every 30 minutes or shorter(if the water level was low) during this four-hour period. A San <br /> Joaquin County Environmental Health Department representative observed the last half hour of each <br /> test. <br /> Test Results: The completed percolation test form from field measurements is included in the <br /> appendix. Field data includes percolation rates for the holes tested, and provides the basis for septic <br /> system leach trench design recommendations. System design was based on the final readings observed <br /> at the end of the four(4) hour test. Field data is shown in Figure 3. <br /> Results of the percolation tests are summarized in the following table. <br /> Table 2.1- Percolation Test Field Data Summary <br /> Test Hole Depth Final Percolation Rate(minutes/inch) Test Duration Result <br /> 2411-3611 60 4 hours Standard <br /> 4811-6011 60 4 hours Standard <br /> 72"-80" 120 4hours Non-Standard <br /> Test conducted July 8,2022. <br /> Proposed System Design <br /> Percolation field test data, in combination with soil texture observations and tests, indicate that on-site <br /> disposal of wastewater is a feasible option for the project.A specific septic system design is not <br /> proposed at this time, as additional field testing (percolation,geotechnical) is required to confirm soil <br /> profile and groundwater separation characteristics for each leach field. Detailed wastewater system <br /> designs will be provided for each of the six(6) commercial buildings, based on employee count, number <br /> of work shifts, and local soil and groundwater conditions. <br /> 31 Page <br />