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NLS§ 2.2,3.I, SSS§ 4.2. Surrounding properties are currently farmed and have been for decades, <br /> so the potential for nitrate contamination of the underlying groundwater can be considered <br /> significant. <br /> NLS§2.3, SSS§ 4.3, 4.4,4.5. The domestic well on the property was sampled at the well head and <br /> tested for total alkalinity and nitrate. The alkalinity is low at 110 mg/L and the nitrate concentration is <br /> 36.1 mg/L. <br /> TABLE 3 <br /> SUBJECT PROPERTY DOMESTIC WELL: <br /> ANALYTICAL RESULTS OF TESTED CONSTITUENTS <br /> SAMPLE ID NITRATE AS NITRATE DBCP/EDB TOTAL ALKALINITY pH <br /> Well 36.1 mg/L ND-Non Detect 110 mg/L 7.53 <br /> MCL=45 m /L <br /> Discussion on the Alkalinity Requirement for Nitrification <br /> The nitrate-nitrogen loading calculations are contingent upon the environmental factors required for <br /> nitrification to occur. These conditions include soil pore-space oxygen content, soil temperature, <br /> pH, electrical conductivity, organic matter, cation exchange capacity, and alkalinity. Alkalinity in <br /> wastewater effluent is derived from well water, in addition to the introduction of wastes. <br /> Nitrification consumes approximately 7.1 mg of alkalinity for every mg of ammonia-nitrogen (NH4_ <br /> N) oxidized. Nitrification of the average Total Nitrogen (TN) concentration of 50 mg/L, as <br /> determined below, would require: 50 mg/L NH4-N x 7.1 mg CaCO3 = 355 mg/L alkalinity. The <br /> alkalinity in groundwater was determined to be 110 mg/L. Therefore, soil alkalinity and alkalinity <br /> from wastes must provide a significant alkalinity concentration for nitrification to occur. Soil pH <br /> was determined to be neutral, thus affecting potential ammonia concentrations. <br /> E. SURFACE WATER INFORMATION <br /> Climatic Data: Mass Water Balance <br /> NLS§ 3.2. <br /> The California Irrigation Management Information System (CIMIS) data has been used for the <br /> nitrate loading analysis below. Deep percolation may occur when the average monthly rainfall exceeds <br /> average monthly evapotranspiration (ETo). Since there is a CIMIS station in Manteca(Station#70),this <br /> Station data was averaged from 2015 to 2019, with the raw data found in Appendix E with the summarized <br /> data below in Table 4. <br /> Page -5- <br /> Chesney Consulting <br />