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The filter bed area may also correspond with the percolation test results. As referenced above, the <br /> application rate correlated with the shallow perc test results of 5 mpi translate to an application rate <br /> of 1.086 gals/ft'/day. Using the ADF of 400 gpd, we find: 400 gpd- 1.086 gals/ft2/day = 370 sq. ft. <br /> filter bed. Therefore,the filter bed size of 1,075 sq. ft. is adequate based on the test results <br /> obtained. The 100%replacement area is directly south of the primary filter bed area into the actual <br /> vineyard, and is also to consist of 1,075 sq. ft. <br /> Wastewater Disposal System Parameters and Appurtenances <br /> Infiltrator Chambers: 34"x 75"x 12"; Filter Bed=300" (25'wide)-34" =9 Chambers. 516" (43'long)_75" <br /> =7 Chambers. 9 x 7=63 Chambers total. <br /> Orenco Biofilter Filtration from septic tank to filter bed(EHD Requirement) <br /> As-Builts of entire system by installer after installation(EHD Requirement) <br /> Monitoring of soil/effluent interface with monitoring ports within the filter bed area with observation <br /> tubes: 4" PVC Tee at soil/effluent interface with a 4" riser flush with the grass surface and a screw- <br /> type cap. (EHD Requirement) <br /> Filter bed should be at grade with surrounding soil surface. � �✓ �f � e <br /> B. Nitrate Loading Mass Balance <br /> A nitrate loading mass balance calculation is illustrated below, for the proposed project. The <br /> calculated or estimated nitrate impact to the soil and ultimately to the groundwater is extremely <br /> difficult to determine due to the number of variables involved. The Hantzsche/Finnemore <br /> Equation is used to estimate the resultant average nitrate-nitrogen concentration in the effluent <br /> recharge water at a volume of 400 gpd, and a Total Nitrogen concentration of 112 ppm. This 112 <br /> ppm concentration was arrived from septic tank effluent analysis from other similar-type, <br /> commercial projects. <br /> HAN7ZSCh[E F NEM EQUATION <br /> R1,(1 -d)+R Nb <br /> Nr= (I+R) <br /> Where: <br /> Nr= Resultant average concentration of nitrate-nitrogen in recharge water-(ppm NO3-N) <br /> I = Volume rate of wastewater entering the soil averaged over the gross developed area in inches per yr <br /> Nw= Total nitrogen concentration of wastewater in N mg/L(112 mg N/L/day) <br /> d = Fraction(%) of nitrate-nitrogen loss due to denitrification in the soil <br /> R = Average recharge rate of rainfall-inches per yr(9.0 in.) <br /> Nb= Background nitrate-nitrogen concentration of rainfall recharge,exclusive of wastewater influences <br /> (ppm NO3-N) <br /> Page -7- J <br /> Chesney Consulting <br />