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The soil in the boring was similar to that described by the Soil Survey. A sandy clay hardpan was encountered to approximately 2 feet below ground surface (bgs), followed sandy clay to the full depth of the hole. The soil log is presented on Plate 10. Discussion of Soil Lithology Based on the soil observed in the boring, there appears to be limited potential for percolation in the shallow 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 percolation test was conducted near the proposed septic disposal area of the Site. The soil boring discussed above was used for the percolation test hole. Percolation test procedures conformed to San Joaquin County Environmental Health Department policy. Preparation and Presaturation of Percolation Test Holes After the boring was advanced by hand auger and the soil logged, the test hole was completed for the percolation testing. Approximately two inches of pea gravel were placed in the bottom of the 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. The percolation test hole was presaturated approximately 24 hours prior to the percolation testing; the hole was filled with water to a height of 12 inches above the bottom of the boring. On the day of testing, the hole was found to be intact and dry. Percolation Test Procedure Live Oak conducted the percolation test for the boring on August 25, 2020. Based on the initial percolation rates observed, a four-hour test was selected. Water level measurements were taken every 30 minutes during this four-hour period. The last 30 minutes of the test were observed by Daria Afonskaia, Registered Environmental Health Specialist at the San Joaquin County Environmental Health Department. An electronic well sounder with a depth accuracy of 1/100th foot was utilized for the water level measurements. The water level was measured against a fixed reference point on the well casing. Measurements were recorded on the data sheet in decimal feet. When necessary after measuring the water level, the hole was refilled with water to a level of approximately six inches above the bottom of the hole. LOGE 20-38 Page 6