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collected in a clean, dry, stainless steel bowl, then decanted into a plastic container and <br />placed on ice for transport. <br />Nitrate was detected in the May 17 sample at a concentration of 0.4 mg/L-N and in the <br />May 19 sample at a concentration of 0.2 mg/L-N. Live Oak then averaged the <br />concentrations of the two samples, for a value of 0.3 mg/L-N to represent the nitrate <br />concentration of rain. <br />Because the San Joaquin County Environmental Health Department has requested that <br />local and recent data be utilized wherever possible, the concentration of the Lodi <br />rainwater been selected for use in the nitrate loading calculation. <br />Quantity and Quality of Domestic Wastewater <br />Mr. Wutzke indicated that a three-bedroom home will be constructed on the Site. The <br />existing home has three bedrooms. <br />Crites and Tchobanoglous (1998) list a typical flow rate of 50 to 70 gallons per person <br />per day for an individual residence. The San Joaquin County Environmental Health <br />Department has indicated that maximum flow and double occupancy within each <br />bedroom should be considered for the nitrate loading assessment; as a result, a value <br />of 140 gallons per bedroom per day has been selected (personal communication, <br />January 6, 2017). <br />The maximum daily flow for the Site was estimated to be 840 gallons per day (gpd), <br />based on six bedrooms at 140 gallons per bedroom. <br />A typical residential concentration of 35 mg/L of nitrate as N was selected for the <br />proposed residence (Crites and Tchobanoglous, 1998). <br />The estimated flow values discussed here should not be used for the design and sizing <br />of the septic system. The design and sizing of the septic system should utilize the San <br />Joaquin County Environmental Health Department On-Site Wastewater Treatment <br />Systems Standards which incorporate peak and surge flow factors. The estimates used <br />in the On-Site Wastewater Treatment Systems Standards may be greater than those <br />discussed here. <br />Denitrification Reductions <br />Denitrification is a process that occurs in the septic system drain field whereby certain <br />bacteria oxidize the nitrate (NO3) in the wastewater and release nitrogen gas (N2) to the <br />atmosphere. Due to the biologic processes in the shallow soils, nitrogen in the drain <br />field may undergo a reduction between 10 percent to 35 percent. Soils with higher clay <br />content, moist soil conditions, high pH, and organic material denitrify by about 35 <br />LOGE 1934 Page 10