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The Particle Size Analysis, and Nitrogen Contents for the two tested soil samples are summarized m the following Table: SOIL ANALYSIS DEPTH SAND% SILT% CLAY% USDAIUSCS 5NITRATE-N SOIL TEXTURES NT 10 Ft 32% 32% 36% Clay Loam/Sllty Lean Clay m 25 Ft 28% 36% 36% Clay Loam/Silty Lean Clay 11 ppm As noted, the nitrate-nitrogen concentration decreased 39% from the 10-foot depth where there is 18 ppm NO3 N down to 11 ppm NO3 N at the 25-foot depth. These nitrate-nitrogen concentrations are medium-to-low. The decrease in concentration with increasing depth indicate that denitrification may be occurring. This will contribute a lower concentration of nitrate in percolating vadose zone water down to the zone of saturation. Additional soil parameters that were tested which pertain to nitrate loading assessment originating from septic system effluent include: The organic matter content,pH, cation exchange capacity (CEC), clay content percentage, and soluble salts. Considering the property soils have not been under agricultural production for many years,the organic matter content in these soils is low, also contributing a low estimated nitrogen release (ENR). The significance of cation exchange becomes important when the chemistry of septic effluent is analyzed. Nitrogen in septic tank effluent consists of approximately 75%N as the ammonium ion form and 25%N in the organic form. If the ammonium ion is bound and eventually used, nitrification cannot occur. Consequently, the pH, along with the CEC, have significant influence on ammonium molecules. The CEC measures the ability of the soil to theoretically trap and hold ammonium molecules. The two soil samples indicate a comparatively high CEC of 28 meq/100 g at the 10-foot depth and 27 meq/100 g at the 23-foot depth. This suggests there is a greater potential for the retention of ammonium molecules by microbial uptake and suppression of nitrification. In addition, the soil pH is alkaline which also promotes denitrification. Nitrification is an aerobic reaction accomplished predominately by autotrophic bacteria. Both the shallow and deeper subsurface soils possess sufficient clay content to_bind the ammani>w ions and to create microsites within the clay lattices that are anaerobic thus forcing denitrificatigm. 6o C. PERCOLATION TEST RESULTS As noted in the Introduction, a new effluent disposal area south of the existing office building was determined by Mr. David Lagorio. Consequently,percolation testing was done in this area, as denoted on the attached Site Plan. There are no domestic wells to the south of the subject property that were within 100 feet of the south property border, and therefore not within 150 feet of the future effluent disposal area. 4 Chesney Consulting