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r7tZes�t 2.3. The existing on-site domestic well water was sampled for the listed constituents with the ults found below in Table 2. A new domestic well is to be installed in the southeast corner of the developed portion of the property. TABLE 2 WATER WELL NITRATE NITROGEN and DBCP TEST RESULTS ANALYTE CONCENTRATION FOUND MAXIMUM CONTAMINANT LEVEL (MCL) Nitrate 15.5 ppm NO,N 10 ppm NO,-N(45 ppm NO,) (Nitrate as Nitrogen) DBCP/EDB ND 0.2/0.05 ug/L (Non-Detect) Alkalinity 200 ppm N/A pH 7.7 ------ Calculation of Alkalinity Requirement for Nitrification The nitrate-nitrogen loading calculations 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 well water, 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 45 mg/L, as determined below, would require: 45 mg/L NH4-N x 7.1 mg CaCO3 =320 mg/L alkalinity. The alkalinity in groundwater was determined to be 200 mg/L. Therefore, soil alkalinity and alkalinity from wastes must provide a significant alkalinity concentration for nitrification to occur. Soil pH was determined to be acidic,thus affecting potential alkalinity concentrations. SURFACE WATER INFORMATION Mass Water Balance NLS§3.2. The California Irrigation Management Information System(CIMIS) data has been used for the nitrate loading analysis below. Deep percolation may occur when the average monthly rainfall exceeds average monthly evapotranspiration(ETo). Since there is a CIMIS station in Manteca(Station#70), this Station data was averaged from 2015 to 2019. The data is summarized below in Table 3. Page -3- Chesney Consultin;