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TABLE 4 UNDERLYING WATER TABLE ANALYSIS WATER TABLE UNDER PROPOSED EAST WATER TABLE UNDER PROPOSED WEST LEACHFIELD(ELF WATER TABLE) LEACHFIELD(WLF WATER TABLE) ANALYTE LEVEL FOUND ANALYTE LEVEL FOUND Nitrate 156 ppm Nitrate BDL Total Dissolved 1640 ppm Total Dissolved 12,120 ppm Solids Solids pH 7.6 pH 7.0 Chloride 74 ppm Chloride 3,723 ppm Sodium 466 ppm Sodium 2,189 ppm I Total Alkalinity 937 ppm Total Alkalinity 2,121 ppm Static -13 ft bgs Static -11 ft bgs Groundwater Groundwater Level Level Calculation of Alkalinity Requirement for Nitrification The nitrate-nitrogen loading calculations on Page 14 are contingent upon the environmental factors required for nitrification to occur. These conditions include soil pore-space oxygen content, soil temperature, pH, electrical conductivity, organic matter, cation exchange capacity, and alkalinity. Alkalinity in wastewater effluent is derived from the domestic well water supply in addition to the introduction of wastes. Nitrification consumes approximately 7.1 mg of alkalinity for every mg of ammonia-nitrogen (NH4-N) oxidized. Nitrification of the average Total Nitrogen(TN) concentration of 68 mg/L, as determined on Page 14 would require: 68 mg/L NHq N x 7.1 mg CaCO3 =618 mg/L alkalinity. Although the alkalinity in the domestic water supply is presently unknown, it can be assumed that it will be high based on the water table results and will theoretically inhibit nitrification. Mounding Analysis Reference is made to the encountered groundwater table at 13 feet below existing grade under the proposed ELF. Analysis will be conducted on this disposal area since the anticipated wastewater flows will be significantly higher than for the Office Trailers WLF. The depth to groundwater under the ELF can be considered relatively shallow and may induce a phenomenon known as the "mounding effect' in which percolating effluent encounters the water table, or restrictive stratum and cannot disperse laterally in a certain time frame. Consequently, a mound forms under the disposal field creating saturated flow conditions and decreasing the distance the effluent must travel under unsaturated flow for effluent treatment to occur. An equation developed by Finnemore and Hantzsche(1983) is used below to predict the long-term maximum rise of the mound: 9 Chesney Consulting