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{ <br /> From the anticipated wastewater,characteristics described above, nitrate-nitrogen loading will be emanating <br /> from the two different wastewater sources: 1.)public and employee restrooms and 2.)The two residential <br /> structures. Therefore, these two nitrogen sources will be quantified independently. The two <br /> public/employee restrooms may be at a higher concentration than what would normally be found in a typical <br /> domestic or household system. This can be attributed to the lack of a dilution effect that graywater from <br /> showers,laundry, and dishwashing would provide from a household. Analyses of septic system effluent <br /> from commercial systems within San Joaquin County has indicated the effluent to have a nitrogen <br /> concentration of 113 mg NIL. A value of 66 mg NIL will be used for the apartment and residential <br /> structures for the nitrate loading calculations that follow the restroom calculations. <br /> NLS§3.4,3.5,3.6. PREDICTED NITRATE-NITROGEN LOADING FROM THE PUBLIC <br /> RESTROOM AND THE EMPLOYEE RESTROOM USINGTH MUM AVERAGE DAILY <br /> FLOW (ADF) OF 300 gpd BASED ON THE SAN JOAQUIN C f TY S WAGE STANDARDS <br /> DESCRIBED,AND TAKING THE ENTIRE PROJECT AREA F 1.95 A RES INTO <br /> CONSIDERATION: <br /> HANTZSCHE/FINNEMORE EQUATION <br /> IN,,, 1 - d +R Nb <br /> Nr= (I+R) <br /> Where: <br /> Nr= Resultant average concentration of nitrate-nitrogen in recharge water-(ppm NO,-N) <br /> I = Volume rate of wastewater entering the soil averaged over the gross developed area in inches per yr <br /> f Nw= Total nitrogen concentration of wastewater in mg NIL <br /> d = Fraction(%) of nitrate-nitrogen loss due to denitrifi atio)ine soil <br /> R = Average recharge rate of rainfall -inches per yr S§Ne= Background nitrate-nitrogen concentration of rainfal ec , exclusive of wastewater influences <br /> (ppm NO,-N) <br /> f <br /> Values and Assumptions <br /> r <br /> I= 300 gpd x 350 d%Lfo `o eration= 105,000 gals=total WW1 1:03'1cqt 1 .. <br /> 1, 1.95 r) c x 43,560 sq ft/Ac x (1 ft/12 in.) <br /> Y4i.L / <br /> Nw = 113 mg NIL: 10%reduction from th greas interceptor tank that must be installed for the <br /> deli/kitchen= -0.1)113 = 102 mg n 10% reduction from a second septic tank = <br /> 0-0.0102 =92 mg NIL <br /> d = Assume 25% uc to the clay percentages at the 10 and 15 ft depths in the native soil and therefore <br /> high denitrification potential. <br /> R = 13 in/yr. <br /> Ne= Assumed to be 0.1 ppm NO,-N <br /> 1.98 in/yr(92 mg N/L) (1 -0.25)+(13 in/)r x 0.1 mg/L) <br /> Nr =D <br /> (1.98 in/yr+ 13 in/yr) <br /> rnitrate-nitrogen QNO,- G <br /> pm as nitrate O,) <br /> 9 <br /> Chesney Consulting <br />