SU0008968 SSNL - Laserfiche WebLink

Home Browse Search

deep, and were excavated by hand auger (Table 2). The boring locations are indicated on Plate 9. The soils in the borings were similar though less clayey than those described by the Soil Survey. For borings P1 and P2 the soil was gravelly silt to two feet depth, followed by gravelly sand to the remaining depth of the borings. For borings P3 and P4, the soil was gravelly silt to two feet depth, followed by silty sand to the remaining depth of the borings. The logs for the soil borings are presented in Plates 10 and 11. Discussion of Soil Lithology Based on the soils observed in the borings, there appears to be moderate potential for percolation in the test locations. Sandy soils generally have a much greater potential for percolation than fine-grained or cemented soils. However, a percolation test is the only 4i 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 on each proposed parcel of the Site. The soil borings discussed above were used for the percolation test holes (Plate 9). Percolation J test procedures conformed to San Joaquin County Environmental Health Department policy. Preparation and Presaturation of Percolation Test Holes After the borings were advanced by hand auger and the soils logged, the test holes were completed for the percolation tests. Approximately one inch of pea gravel was placed in the bottom of each open soil boring, followed by a 1.5-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 tests. 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, be#tr holes were found to be intact and dry. ' Percolation Test Procedure Live Oak conducted the percolation tests for the borings on October 21 and 25, 2011. Due to initial percolation rates observed, four-hour tests were selected. Water level measurements were taken every half-hour during this four-hour period. The last half- 5' hour of each test was observed by Michael Escotto, Senior Registered Environmental Health Specialist at the San Joaquin County Environmental Health Department. LOGE 1126 Page 7