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rr This is a surprising] high umber of permits in this specific area of San Joaquin County because the soil structure is composed mostly of sand, and the locale is sparsely developed. This may be due to inadequate systems that were originally installed. The project site has level terrain; consequently, there will be no need to incorporate design considerations for slopes within the leachfield area. It is my understanding that the Men's and Women's Restrooms will be detached from the primary building and located near the leachfield area./ Consequently, there is not a dramatic elevational difference between the restroom location and the disposal field area. B. SOIL PHYSICAL CHARACTERISTICS AND ANALYTICAL TEST RESULTS The United States Department of Agriculture- Soil Conservation Service(USDA-SCS) indicates the on-site soils to consist of a Delhi loamy sand (#142). SSS§ 5.�. The surface and subsurface soil investigation and testing began with drilling a 40-inch perc test boring. From a 10-foot deep boring completed 300 feet to the west, it is known that the soil becomes sandier with increasing depth. NL § 1.1 .2 As the noted on the A&L Laboratory Soil Analysis Reports, chemical analyses of the tw soil ' les from the 16 inch depth and the 40-inch depth quantify several constituents that will in I trate loading from this project. The important parameters for nitrate loading assessment/ are the organic matter, pH, cation exchange capacity(CEC), clay content percentage, along with nitrate-nitrogen content. Total Kjeldahl Nitrogen(TKN) content was not measured since the soil is too sandy for TKN to be of consequence. As noted,the organic matter in the soil is very low in both soil samples. This suggests a very low potential for future nitrate-nitrogen loading from indigenous nitrogen soil content. It may also suggest a low denitrification potential since organic matter is needed for promotion of denitrification. Since septic effluent is composed predominately of ammonium(NH4), the pH, along with the CEC, are significant influences on ammonium molecules. The pH of the soil is acidic which may not inhibit ammonium formation and therefore stability, and may create a propensity for ammonium (NH4) formation. The CEC measures the ability of the soil to theoretically trap and hold ammonium molecules. Cation Exchange Capacities of the soil samples are very low due to the low clay and high sand content. This suggests there is little potential for the retention of ammonium molecules for microbial uptake, and suppression of nitrification. �N5.3 Table 1 below summarizes the subsurface soil characteristics encountered from the 24" A§ and 40" depths, illustrating the particularly high sand content percentages at each of the sampled depths: 3 Chesney Consulting