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Soil Suitability/Nitrate Loading Study 1�erracon <br /> Avanti Nut Co. ■ Stockton, CA <br /> May 19, 2016 ■Terracon Project No. NA167038 <br /> Table 4. <br /> Typical Quantity of Effluent. <br /> Category Total People Average Quantity per Average Daily Flow per Parcel <br /> per Day Person <br /> Permanent 4 *15 gal/day/employee (4 employees*15 gpd) =60 gpd <br /> Employees 60 gpd*6/7=51.4 gpd <br /> Average Daily Flow from Existing Septic 51.4 gallons per day <br /> Note:gpd is gallons per day. <br /> *Value cited from Crites, R. & Tchobanoglous, G., Small and Decentralized Wastewater Management Systems, 1998. Table 4-2: <br /> Typical Wastewater Flowrates from Commercial Sources. <br /> The average total nitrogen concentration of domestic wastewater is normally considered to be 20- <br /> 85 mg/L-N with 35 to 45 mg/L-N being typical (Crites and Tchobanoglous, 1998). It is estimated <br /> that commercial use will have higher concentrations of total nitrogen when compared to residential <br /> use. It is estimated that the average concentration for total nitrogen in wastewater for the project <br /> Iis approximately 85 mg/L-N over the long term. <br /> I2.3.4.2 Denitrification Estimate <br /> Denitrification is an important process which occurs within the leach field whereby certain bacteria <br /> utilize the oxygen in the nitrate (NO3) and release nitrogen gas (N2) to the atmosphere. <br /> Denitrification is expressed as a percentage, and the normally accepted range is 10 percent to 35 <br /> percent. Soils with higher clay content, moist soil conditions, high pH, and organic material <br /> denitrify by about 35 percent, and soils with high sand content and fast percolation rates are <br /> estimated to denitrify at a lower rate, about 10 percent to 15 percent. <br /> tEven though the near surface soils consit of clay, the on site system will likely consist of pits to a <br /> depth of 25 feet bgs. Sand with clay was encountered at a depth of approximately 20 feet as <br /> indicated previously. For this reason, a denitrification factor of 25 percent was selected for the <br /> site. <br /> 2.3.5 Nitrate Loading Scenario <br /> ' A nitrate loading scenario was performed to determine the impact from the proposed project. The <br /> scenario utilizes the variables discussed previously which represent the estimated conditions and <br /> uses associated with this project. The following table presents a summary of the nitrate loading <br /> calculation for the site, as presented in Plate 8. <br /> i <br /> 1 <br /> Responsive ® Resourceful ■ Reliable 13 <br />