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In addition, septic tank effluent concentrations from various researchers that have been published in Small and Decentralized Wastewater Management Systems, by Crites and Tchobanoglous are found in Columns 3 and 4. These two columns illustrate the effect effluent filtration has on certain constituents of the effluent, particularly BOD and TSS. Filtration seems to have very little effect on the nitrogen fractions of the effluent. Column 5 illustrates septic tank effluent concentrations for the constituents listed that have been determined by the U.S.E.P.A. TABLE 5 tFa aboratory Crites and Crites and U.S.E.P.A. ATE Analysis of Tchobanoglous: Tchobanoglous: Commercial Septic With Effluent Filter Without Effluent Filter System Effluent Ammonen(NHa N) 103 mg/L 40 mg/L 40 mg/L 6-18 mg/L Otrogen 10 mg/L 28 mg/L 28 mg/L 30-82 mg/L e BDL BDL BDL BDL Togen 113 mg/L 68 mg/t. 68 mg/L 35-100 mg/L Totaled Solids 72 mg/L 80 mg/L 30 mg/L 200-290 mg/L BiocOxygen 21 mg/L 180 mg/L 130 mg/L 200-290 mg/L DOD,) PH 7.7 N/A N/A N/A Total Alkalinity 983 mg/L 60-120 mg/L 60-120 mg/L N/A B. CALCULATED NITRATE-NITROGEN LOADING NL9j:33:l11e calculated or estimated nitrate-nitrogen impact to the soil and ultimately to the groundwater is difficult to determine due to the number of variables involved. These variables include 1.)Variability in wastewater flows, nitrogen concentrations and dilution effects, 2.) Impact from upgradient nitrate sources, particularly agricultural farmland, 3.) Changes in groundwater directional flow and elevation, 4.) Denitrification potential of the underlying soil, and 5.)Rainfall recharge. As noted in Table 5, the Total Nitrogen(TN) content is substantially higher in the tested septic tank effluent thanTn the other published sources. Therefore, as a safety factor, the Total Nitrogen of 113 mg/L will be used in the nitrate loading calculations. Various scientific methods are used to estimate nitrate-nitrogen loading. This study uses the Hantzsche/Finnemore Formula to predict the average concentration of nitrate-nitrogen in effluent recharge water: 13 Chesney Consulting