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• SpahosyProperty Page 3 <br /> Our Project NuMber: LGS090501 <br /> 4 April 14,2009 <br /> The average total nitrogen concentration of domestic waste water is normally considered to be <br /> 20-85 mg/L-N with 35 to 45 mg/L-N being typical (Crites and Tchobanoglous, 1998). It Is <br /> estimated that commercial use will have higher concentrations of total nitrogen when compared <br /> to residential use. It is estimated that the average concentration for total nitrogen in waste <br /> water for the hotel aspect of the project is near residential use, approximately 45 mg/L-N over <br /> the long term. The service station and commercial/retail aspect of the project is approximately <br /> 85 mg/L-N over the long term, and the short order restaurant will have a concentration near <br /> approximately 60 mg/L-N. <br /> The adjusted nitrogen long term average using a weighted average is 58 mg/L-N. Below is the <br /> long term weighted average of nitrogen in the proposed development waste water. <br /> Weighted ver a ofotaLfflLoclen <br /> Hotel: 2,100 gpd x 45 mg/L-N = 94,500 <br /> Restaurant: 1,050 gpd x 60 mg/L-N = 63,000 <br /> Commercial/retail: 900 gpd x 85 mg/L-N = 76,500 <br /> 234,000 / 4,050 gpd = 58 mg/L-N <br /> Denitrification_Esti�ni e <br /> Denitrification is an important process which occurs within the [each field whereby certain <br /> bacteria utilize the oxygen in the nitrate (NO.3) and release nitrogen:gas (Nz) to the atmosphere. <br /> Denitrification is expressed as a percentage, and the normally accepted range is 10 percent to <br /> 35 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 /> A denitrification factor of 35 percent was selected for the Site because of the fine grained <br /> nature of the soils. <br /> Nitrate Loading Scenario i <br /> A nitrate loading scenario was performed to determine the impact from the proposed project. <br /> The scenario utilizes the variables discussed previously which represent the estimated ; <br /> conditions and uses associated with this project. The following tablei presents a summary of the <br /> nitrate loading calculation for the site (also, see Plate 2). <br /> Table 2. <br /> S mmary of Nitrate lass Balance E uation <br /> Result Average Effluent Leachfield Deep <br /> Parcel (Nc)* Acres(A) Daily Flow Concentration Denitrification Percolation <br /> (mg/L-N) (Q)(gpd) (NW) (d) of Rainfall <br /> (mg/L-N) (a)(in) <br /> 1 14.1 17.1 4,050 58 35% 5.76 <br /> *Maximum contaminant level(MCL)Far nitrate in drinking water i510 mg/L-N. <br /> I <br /> 902 industrial Way•Lodi,CA 95240.209.367.3701 -Fax 209.369.4,223 (92007 Nall 0, 4ndarsan&Assoctares.Inc <br />