SR0083203_SSNL - Laserfiche WebLink

Home Browse Search

20 January 2021 Project No. 20-6284 Page 7 of 14 AdvancedGeo An Employee-Owned CCompony 5.1. SOIL PROFILE PIT INCLUDING DEPTH AND DIMENSIONS The percolation test hole was located in the disposal field area of the proposed septic system. The percolation test hole was advanced to a depth of 42 inches bsg using a four - inch diameter hand auger (Figure 2). 5.2. SOIL LITHOLOGY AS RELATED TO FUTURE ONSITE SEPTIC USES The soil was visually described in accordance with the Unified Soil Classification System (USCS) by a representative of AGI working under the supervision of a California Professional Geologist. The soil collected from the percolation test hole boring consisted of dry, clay with sand from surface grade to approximately 24 inches bsg, silty sand from 24 to 36 inches bsg, and sand with silt from 36 to 42 inches bsg. The soil type is considered semi -permeable and should be sufficient for liquid waste disposal and treatment. 6.0. PERCOLATION TEST INFORMATION A percolation soil suitability test was performed at the site under EHD permit No. SR0083092 using a four -inch diameter soil boring established to a depth of 42 inches bsg. A site map showing the approximate location of the percolation test hole is illustrated in Figure 2. A precise description of the location and construction of the percolation test hole is included in Appendix D (EHD form 42-03 revised 11/02/2009). The soil suitability study was conducted within the area of the proposed septic system leach field. 6.1. NUMBER OF PERCOLATION TESTS PERFORMED One shallow percolation test was performed at the site. The appropriate percolation test procedure established by the EHD was followed for the test (Procedure #3). The percolation test hole was pre-soaked overnight for 24 hours followed by a 30 -minute percolation testing period. 6.2. CONSTRUCTION OF PERCOLATION TEST HOLE On 14 January 2021, one boring was advanced for a shallow percolation test. The boring was advanced using a four -inch diameter hand auger to a depth of 42 inches bsg. Following borehole advancement, the sides of the boring were scraped, and loose material was removed from the borehole. Once the borehole was cleared of loose material, two inches of fine gravel was added to the borehole. The borehole was then filled with water to a depth of 12 inches above the gravel at the time of 0840. The test hole was then covered for 24 hours to allow for complete saturation of the borehole.