Laserfiche WebLink
1 KLE/NFELDER <br /> Bn9ht F4eple.Nl9f blullans. <br /> ' 10 NITRATE LOADING CALCULATIONS <br /> 1 <br /> Per SJCEHD requirements, the following summarizes our nitrate loading calculations for the <br /> entire parcel, including the existing two septic systems and the proposed septic system. As a <br /> ' conservative approach, the MicroSepTec system discussed above will not be taken into <br /> consideration in our nitrate loading calculations. Instead, all systems will be treated as <br /> conventional septic systems with septic tanks and leach fields. <br /> The state drinking water standard for nitrate is 45 milligrams per liter (NO3) and 10 mg/I as <br /> ' Nitrogen (N) in groundwater. In our evaluation of nitrate loading, we have used the Hantzsche <br /> mass balance equation (source: Predicting Groundwater Nitrate-Nitrogen Impacts, Hantzsche <br /> and Finnemore (1992)), which is presented below. <br /> NC _ I(Nw)(1-D) + R(Nb) <br /> ' (I+R) <br /> The selection of parameters used in the equation was based on previous studies and <br /> investigations performed by our firm and others, San Joaquin County Sewage Standards, and <br /> ' information provided in a report dated March 19, 1997 prepared by the Questa Engineering <br /> Corporation and authored by Mr. Hantzsche for a development in the Stockton area. <br /> Average calculated nitrate-nitrogen in groundwater resulting from leach field source <br /> Nc _ <br /> and precipitation—mg/I, as N. <br /> Volu waste water entering the soil averaged over the gross developed area <br /> ' I = Q1.0i inches per ye (calculated as follows: ([14,700 gal/week x 52 weeks/year x <br /> gal]/[26.31 acres x 43,560 sq ft/acre]) x 12 inches/ft) <br /> Nitrate concentration of nitrified leach-field effluent (mg/1) = 45 mg/I (The Hantzsche <br /> and Finnemore (1992) technical paper indicates that the average total nitrogen <br /> NW = <br /> ' concentration in septic tank effluent ranges from 35 to 45 mg/I. This range was also <br /> reported in the 1996 Dames and Moore technical memorandum.) <br /> ' <br /> 20162869.001 A/STO1 6R38644 Page 10 of 15 April 19, 2016 <br /> ©2016 Kleinfelder <br />