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Environmental Health Department, to perform the percolation testing and install the septic system less than 150 feet from their own and neighbors' wells. The new system will be at least 100 feet from all wells. The surface and near-surface soil in the borings was similar to that described by the Soil Survey; deeper soil was found to be very sandy. A sandy silt hardpan was encountered to a depth of 5 feet, followed by silty sand to 6 feet, silty clay to 10 feet, fine sand to 13 feet, medium sand to 20 feet, clayey sand to 23 feet, and silty fine sand to the full depth of the hole. The soil log is presented on Plate 11. Discussion of Soil Lithology Based on the soil observed in the borings, there appears to be limited potential for percolation in the shallow soil zone, but good potential for percolation in the deep soil zone. Sandy soils generally have a much greater potential for percolation than fine- grained or cemented soils. However, a percolation test is the only accepted method for determining the suitability of the soils for a septic disposal area. Percolation test results are discussed in the following section. Percolation Test A shallow and deep percolation test was conducted in the proposed septic disposal area of the Site. The soil borings discussed above were used for the percolation test holes. Percolation test procedures conformed to San Joaquin County Environmental Health Department policy. Preparation and Presaturation of Percolation Test Holes After the borings were excavated and the soil logged, the test holes were completed for the percolation testing. Approximately two inches of pea gravel were placed in the bottom of each open soil boring, followed by a 2.0-inch diameter PVC pipe with perforations on the bottom. Pea gravel was then used to backfill a few inches of the annular space. Live Oak presaturated the percolation test holes approximately 24 hours prior to the percolation testing. The holes were filled with water to a height of 12 inches above the bottom of the boring for the presaturation. On the day of testing, the holes were found to be intact and dry. Percolation Test Procedure Live Oak conducted the percolation test for the borings on September 9, 2020. Due to the soil types present, a four-hour test was selected. Water level measurements were taken every 30 minutes during the four-hour period. The last 30 minutes of the test LOGE 20-41 Page 5