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B. SOIL PHYSICAL CHARACTERISTICS-AND ANALYTICAL:TEST RESULTS The United States Department of Agriculture = Soil Conservation:Service(USDA�SCS} indicates the roe soils are Stockton cla #250 The Soil Surve of San Jo um Coun statesthat p p rtY Y( }: � typermeability is slow in these soils,-which-was observed inthe top.four feet of soil by the percolati]Jn6test conducted.SSS§ 5.2. The surface and subsurface soil investigation began on May 30,-2008 with the drilling a 25 feet deep exploratory boring and three percolation test borings with a truck mounted drill rig and solid stem auger. The test borings were drilled near the northeast triangular corner of the .property as illustrated on the Site Plan; where the disposal-area is to be installed. NLS§1.1, 1.2. Soil cutting samples from the 25-ft exploratory test boring were retrieved at 42. �s°tib inches, 12 ft and 25 ft for physical and chemical=analysis.; No Standing water; or saturated soil was - observed"in this boring. As the noted on the-A&L Laboratory Soil Analysis Reports in Appendix B_ , chemical analyses of the three soil samples quantify several constituents that influence nitrate loading for this project.. The important parameters for.nitrate loading assessment are the organic matter,pH, cation exchange capacity(CEC); clay q-9htent percentage,.along with nitrate-nitrogen content of the soil. As noted, the organic matter in the surface soils is higher than the subsoils, which is to be expected given the property was once farmed. The nitrate-nitrogen:concentration is very low throughout the soil profile and decreases in concentration in each of the subsequent deeper depths from.4 ppm to 2 ppm. Below the 12 ft depth, the decrease in nitrate-nitrogen concentrations may suggest that the denitrification potential within the soil profile is reducing the nitrogen concentrations. Because septic effluent is composed predominately of ammonium(NHA the pH, along with the CEC, are significant influences on ammonium Cmolecules. The pH of the soil is alkaline throughout the soil profile which may have an effect on ammonium formation and stability. The CEC measures the ability of the soil to theoretically trap and hold ammonium molecules. Cation Exchange Capacities of the soil samples are very high. This suggests there is a high potential for the retention of ammonium molecules for microbial uptake, and`may also be a reason why there is low soil nitrogen. NLS§ 3.3, SSS§ 5.3, 5.4. Table 1 below summarizes the surface and subsurface soil physical and chemical characteristics from the three soil samples retrieved from the exploratory boring: 3 Chesney Consulting