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77uthe east of the subject property along Highway 120 are commercial and industrial facilities, all of which are on decentralized wastewater management systems. The property is zoned I-W, Indstrial Warehousing. SSS§3.1 .3,3.4, 3.5, 3.6. Applications on microfiche file with the EHD reveal that there have been,6ight ermits issued for repairs/additions to existing systems within a one mile radius `1 surroundiri project site on Highway 120. This is a surprisingly high number of permits in thisc lv} 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 originally installed. The project site has level terrain; consequently, there will be no need to incorporate design considerations for slopes within the filter bed area. Nor is there a dramatic elevational difference between the proposed office building 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§ 5.2 The surface and subsurface soil investigation and testing began with drilling a 10-foot de bo in the proposed effluent disposal location using a truck mounted drill rig. Soil cutting g P P P gg samples for analysis were retrieved from the two, five, seven and ten foot depths. NLSO.�',",,1.2. As the noted on the A&L Laboratory Soil Analysis Reports, chemical analyses of the` four soil' am es quantify several constituents that will influence nitrate 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 all four 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 alkaline which may inhibit ammonium formation and stability, and may create a propensity for ammonia(NHO 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 content. This means there is little potential for the retention of ammonium molecules for microbial uptake, and suppression of nitrification. AN 5.3 Table 1 below summarizes the subsurface soil characteristics encountered from the 10 ft boring, illustrating the particularly high sand content percentages at each of the sampled depths: 3 Chesney Consulting