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LOGE 1726: Phillips/Michael David NLS Addendum Page 2 September 20, 2017 • PERCOLATION TEST A new percolation test was conducted on the Site in the proposed septic disposal field for the new production office facility. Soil Borings On September 8, 2017, Live Oak excavated a shallow soil boring on the Site for the purpose of conducting a percolation test. The boring was four inches in diameter, 3.35 feet deep, and was excavated by hand auger. The location of the boring is indicated on Plate 3. The soil in the boring was similar to that encountered in the original report. Partially cemented sandy silt was encountered to a depth of 2.5 feet below ground surface, followed by silty, fine sand to the full depth of the hole. The log for the soil boring is presented in Plate 4. Discussion of Soil Lithology Based on the soils observed in the borings, there appears to be moderate to good potential for percolation. 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 One shallow percolation test was conducted on the Site; the shallow 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 2 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. Live Oak presaturated the percolation test hole 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 for the presaturation. On the day of testing, the percolation test hole was found to be intact and dry. Percolation Test Procedure Live Oak conducted the percolation test for the boring on September 12, 2017. Due to rapid initial percolation rates observed, a one-hour test was selected. Water level measurements were taken every ten minutes during this four-hour period. Scott Sangalang, Registered Environmental Health Specialist at the San Joaquin County Environmental Health Department, observed the percolation test.