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S§ 5.2 As detailed in the original Studies completed for the nearby St. Bernard's pro7deepcompleted to determine subsurface soil characteristics and depth to groundwabelow regional grade, exists a silty/clayey gravelly/cobble soil that extends down to grou Rust mottling was not observed in the percolation test borings which would indicate seasonal soil saturation. Zj1A. _2?As noted on the Denele Laboratory Soil Analysis Reports found in Appendix B, es of the soil samples from the disposal area quantify the 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), and nitrate-nitrogen content. The nitrate-nitrogen and organic matter concentrations are very low at the 36-48 inch depth. This suggests a low potential for future nitrate-nitrogen loading from indigenous nitrogen content within the soil. 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(NH3) formation. The CEC measures the ability of the soil to theoretically trap and hold ammonium molecules. Cation Exchange Capacities of the soil samples are high at the measured depth. This suggests there is a high potential for the retention of ammonium molecules for microbial uptake, and suppressi of nitrification. _XW5.3 able 2 below summarizes the subsurface soil characteristics encountered from the sam pth between 36-48 inches below grade: TABLE 2 SOIL PROFILE CHARACTERISTICS AND ANALYTICAL TEST RESULTS. . SAMPLE DEPTH SOIL NITROGEN CATION EXCHANGE pH AND Ec SOIL CONTENT CAPACITY CLASSIFICATION 3-4 FT DEPTH 5.0 ppm NO,-N 35.2 meq/1008 7.6 0.60 Sandy Loam (3648 inches) C. PERCOLATION TEST RESULTS SSS 6.2. o assess the permeability of the on-site soils,two percolation test bor mgs-weR co lete in the proposed leachfield location as depicted in the Site Plan found ih ApMadix.,�1 T- e "EH fficial"pert test depth at 36 inches below existing grade gives a comparatively detailed observation of subsurface permeability from approximately 30 to 36 inches in depth. The second test depth at 48 inches was conducted to measure any permeability changes at the four ft depth. As noted in Table 3 below,there is rapid permeability at the 36-inch depth, but permeability decreases by 35% at the 48-inch depth. 3 Chesney Consumg