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FFB. S01LPHYSICAL CHARACTERISTICS AND ANALYTICAL TEST RESULTSStates Department of Agriculture -Soil Conservation Service (USDA-SCS)indicates the on-siteist of a Capay Clay-Urban Land Complex (#122). This correlates with the average clay soilesults of 38% from the samples analyzed from the future filter bed soil. SS§5.2 a surface and subsurface soil investigation and testing began with three( 15-fo t deep borings 7 drill d wi a truck-mounted drill rig: One boring near the center of the Future Filter rea, one boring in the Ex' mg Leachfieldarea, and one boring near the center of the Reserve.Leach ie d area. The Existing Leachfield area is presumably directly west of the office building, where there appeared to be a"green stripe"in the lawn area signifying a potential leachiine. The soil boring was drilled next to this green stripe. Soil samples were taken every five feet for chemical and physical a lysis. In addition; soil samples were also taken from two shallow percolation test borings at the 24�and 366 ch depths from the future filter bed. These three deep borings provided: 1.)A profile of the underlying soil characteristics, 2.)Depth to groundwater, which was found to be approximately I 1 feet below grade, 3.) Saturated formation(first aquifer)material type, analyzed to be predominately a clay soil type, and 4.)A water table sample for analysis,which is discussed on Page 7. No rust mottling was observed in any of the borings that would be indicative of seasonal soil saturation caused by a dramatic rise in the water table elevation. As discussed below, the water table has apparently risen t 8 feet below gr nd surface(bgs)from on-site monitoring well data. NLS§ 1.1, 1.2 As the noted on the SOIL ANALYSIS REPORTS,chemical analyses of the soil samples quantify s eral constituents that will influence nitrate loading from this project. The important parameters for nitrate loading assessment are the organic matter,pH cation exchange capaei (CE ,clay content percentage, along with nitrate-nitrogen�ontent and Total Kjeldahl Nitrogen`(TKN)content.TION measures the organic and ammonia fractions of nitrogen. It was tested for two reasons: 1.)To determine any increase in TKN concentrations under the existing Leachfield for comparison with the other two sample sites, and 2.) To establish a baseline in the event soil under the future filter bed is ever tested for a monitoring program. There was no significant difference among the three soil samples for TKN. As noted,the organic matter in the soil is expectedly low. This suggests a very low potential for future nitrate-nitrogen loading from indigenous nitrogen soil content. 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 moderately alkaline which may slightly inhibit ammonium formation and stability, and may create a small propensity for ammonia(NH,)formation. The CEC measures the ability of the soil to theoretically trap and hold ammonium molecules. Cation Exchange Capacities of the soil samples are in the high teens and twenties,which suggests there is some potential for the retention of ammonium molecules for microbial uptake, and suppression of nitrification. The Standard Penetration Test(SPT)results illustrated ' Table 1 are the number of blows required to drive a standard two-inch O.D. split spoon sampler one foot indisturbed soil with a 140-pound weight falling 30 inches. Relative condition of clay soils from this procedure can be classified as soft,medium, stiff, very stiff and hard. As observed,only two of the SPT tests show a very stiff clay soil, while the remaining soil is classified as stiff. These two tests classifying the soil as stiff were found in the future filter bed area. Consequently, it was decided to drill two additional 15 ft deep borings south of the existing entrance driveway to test for not only for this very stiff clay stratum,but also for more permeable strata(borings could not be drilled to the north because of railroad tracks). The very stiff stratum was not encountered to the south of the proposed filter bed location, signifying this stratum is intermittent. Strata with greater permeability(e.g., sand, silty sand)were also not encountered. 3 Chesney Consulting