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III. NITRATE LOADING STUDY FINDINGS <br />A. WASTEWATER FLOW VOLUME PROJECTIONS AND CHARACTERISTICS <br />Wastewater Flow Volume Projections <br />Typically, loading projections for commercial facilities are based on the maximum anticipated <br />wastewater flows generated by people that occur daily, weekly, monthly, or for singular events. <br />Siegfried has calculated flow volumes from the South Dock Restrooms, the Office in the SWC of the <br />Building, and the North Dock Restrooms to be a total ADF of 600 gpd. This flow volume will be <br />used below in the nitrate loading calculations. <br />Wastewater Characteristics <br />To accurately assess and quantify the anticipated nitrogen concentration emanating from the proposed <br />sanitary sewer septic system, an effluent sample was obtained from the septic tank installed in 2017 <br />that serves a number of Buildings in the Holly Commerce Center. This tank is located directly <br />southeast of the sugar storage silos. <br />Test results reveal a high ammonium concentration of 137 ppm and a comparatively low organic <br />concentration of 9 ppm, for a TKN concentration of 146 ppm. Nitrate is not found in septic system <br />effluent due to anaerobic conditions within the tank, and is therefore not included with the TKN to <br />arrive at TN. This TKN concentration will be used in the loading calculations below. <br />The following Table summarizes the septic tank effluent analytical test results: <br />TABLE 5 <br />SEPTIC TANK EFFLUENT SAMPLED FROM TANK INSTALLED IN 2017 SERVING <br />THE HOLLY COMMERCE CENTER: <br />ANALYTICAL RESULTS OF TESTED CONSTITUENTS <br />SAMPLE ID <br />AMMONIUM <br />ORGANIC NITROGEN <br />TOTAL KJELDAHL <br />pH <br />NITROGEN- NH, <br />NITROGEN (TKN) <br />Holly- S.T. EFF. <br />137 mg/L <br />9 mg/L <br />146 mg/L <br />6.5 <br />B. CALCULATED NITRATE -NITROGEN LOADING <br />NLS§ 3.4, 3.5, 3.6. The calculated nitrate -nitrogen impact to the soil and ultimately to the groundwater <br />is difficult to determine due to the large number of variables involved and variables unknown at this <br />time. These include: 1.) Impact from upgradient nitrate sources, particularly the City of Tracy <br />wastewater treatment plant, 2.) Variability in wastewater flows, effluent nitrogen concentrations and <br />dilution effects from Sugar Cut and stormwater recharge, 3.) Changes in groundwater directional flow <br />and elevation caused by surrounding water bodies. <br />110 <br />Chesney Consulting <br />