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ttp time, calculations cannot be performed to estimate nitrogen concentrations. Similarly, grams of N/capita/day cannot be used since the customers are not living on-site. Therefore, the scientific literature indicates an average N concentration of 62 mg NIL of discharged effluent based upon several studies. It is our opinion that this is reliable data. The N in this figure of 62 mg'N/L is referred to as Total Kjeldahl Nitrogen (TKN) concentrations, which is organic N plus ammonia. These studies were based upon household effluent _ thus the dilemma: will the effluent from the restrooms at the Open Air Mall be equivalent to the N composition of household effluent? Logically, with respect to N alone, we are assuming that it will be. If we project a daily wastewater flow of 30,000 gals, the N Ioading will be approximately 7 - kg N/day, or 1,092 kg N/yr. This effluent.N is approximately 75% ammonium ions and 25% organic N. Upon discharge to the soil, N may undergo mineralization, nitrification, adsorption, biological uptake, denitrification or eventual volatilization. Consequently, we must only look at nitrification occurring on the total N loading rates to arrive at potential nitrate impacts. It must be emphasized that there are numerous factors which lead to the production of nitrates from sewage effluent. There have been several mathematical models formulated to assist in explaining the various processes in the soil environment for nitrate production, although they are extremely complex. A discussion of various soil tests performed, and the characteristics of the subsurface soils under the project site will attempt to assess the potential for nitrate (NO3) production. Nitrification and denitrification are the two main processes controlling NO3 formation and ultimate NO, concentration. Nitrification is dependant upon the transformation of ammonium (NH4) ions to nitrate ions under aerobic conditions by bacterial functions. The soil parameters-analyzed included clay content, organic matter (OM) content, cation exchange capacity (CEC), and pH. Composites were made from the two 25 ft seepage pit test boring sites. One composite was from the five ft depth and the other from the 25 ft depth. The Soil Analysis Report results can be found in the Appendix: Clay content was measured by the hydrometer method (ASTM D-422) and found to be a relatively high average of 33% for all four sample locations. High clay content translates to lower oxygen content of the subsurface soils. Under anaerobic conditions, denitrification is enhanced. 10 Valfey Ag*search