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The project site has level terrain; consequently, there is no need to incorporate design considerations <br /> for slopes within the effluent disposal area. <br /> B. SOIL PHYSICAL CHARACTERISTICS AND ANALYTICAL TEST RESULTS <br /> SSS§5.2. The UC Davis Soil Web designates the soil as a Vernalis Clay(#268), with loamy sand at <br /> 125 cm below grade. Texture analysis by A&L Labs show the soils at 42" below grade in the <br /> proposed filter bed area to be a sandy loam(silty sand). <br /> NLS§ 1.1, 1.2. The surface and subsurface soil investigation began on September 29, 2019 with the <br /> drilling of one 42-inch deep perc test boring. Auger cuttings were sampled from the 42" depth. Five <br /> soil samples were also retrieved in the adjacent almond orchard from a 12" depth and composited for <br /> comparison purposes. As noted on the A&L Laboratory Soil Report in Appendix B, chemical <br /> analysis of the soil samples quantifies a number of constituents that influence nitrate loading for this <br /> project. The important parameters for nitrate loading assessment are the organic matter,pH, cation <br /> exchange capacity(CEC), and the nitrate-nitrogen content of the soil. <br /> The soil nitrate-nitrogen concentration is a medium concentration under the proposed filter bed <br /> location at 18 ppm at the 42" depth. The orchard soils have a very low nitrate-nitrogen concentration <br /> of 2 ppm. <br /> Because septic effluent is composed predominately of ammonium(NH4),the pH, along with the CEC, <br /> are significant influences on the ammonium molecules. The pH of the soil profile is alkaline at over 8. <br /> At this pH, ammonium will have a propensity to convert to ammonia. The CEC measures the ability <br /> of the soil to theoretically trap and hold ammonium molecules. The CEC at 42" is low at 7.8 <br /> meq/100g. <br /> NLS§3.3, SSS§ 5.3,5.4. Table 1 below summarizes the soil physical and chemical <br /> characteristics for the proposed filter bed soil and almond orchard soil: <br /> TABLE 1 <br /> SOIL PROFILE'' " CTERISTIC A <br /> ANALYTICA ' ,EST RESULTS <br /> mus <br /> SAMPLE DEPTH AND A � SOIL SOIL NITRATE- PH,CATION E NCE <br /> (SAMPLE NUMBER ON ASSIFICATION NITROGEN CONTENT CAPACITY <br /> TEST RESULT FORM) <br /> i <br /> FILTER BED Sandy Loam 18 ppm NO,-N 7.8 18.5 meq/100g j <br /> 42"DEPTH <br /> (FB42") <br /> CROPLAND Sandy Clay Loam 2 ppm NO,-N 7.2 9.8 meq/1008 <br /> (ALMOND ORCHARD) <br /> 12"DEPTH <br /> i <br /> (CL 12") <br /> i <br /> Page -2- <br /> Chesney Consulting <br />