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Hantzche and Finnemore Equation Calculator <br />Effluent Quantity (Q) <br />350.00 <br />gals/day <br />Effluent Stream (Nw) <br />35.00 <br />mg/L-N <br />Site Area (A) <br />0.98 <br />Acres <br />Concentration Rain (Nb) <br />1.00 <br />mg/L-N <br />Denitrification (d) <br />0.30 <br />% <br />Average recharge rate of rainfall, in inches <br />per year R <br />3.54 <br />in/year <br />Uniform waste water loading (I) <br />in/year <br />Total Nitrate -N Concentration of waste <br />water percolate (Nr) <br />*4.801 <br />mg/L-N <br />Hantzche and Finnemore Equation <br />I*Nw(1-d)+RNb _ Q*365*12 <br />Nr = (I+R) I A*7.48*43560 <br />Q = Volume of wastewater generated, in gallons per day. <br />Nw = Total nitrogen concentration of wastewater from development, in milligrams per liter. <br />A = Parcel size, in acres. <br />d =Fraction of nitrate -nitrogen loss due to denitrification in the soil. <br />R = Average recharge rate of rainfall, in inches per year. <br />Nb = Background nitrate -nitrogen concentration of rainfall recharge at the water table, <br />exclusive of waste -water influences, in milligrams per liter. <br />I = Volume rate of water water entering the soil averaged over the gross developed area for <br />dwelling unit, in inches per year. <br />Uniform waste water loading (I) 4.80 Site Specific Considerations <br />Within 1 -mile of an area of localized recharge <br />Seasonal high depth to groundwater <br />Thickness (in feet) of vadose zone <br />Total thickness (in feet) of clay in vadose zone and % clay in vadose zone <br />Number of OWTS in 1 -mile radius of site, location and distance of municipal supply wells <br />Nitrate concentration in onsite well, nearby water wells, public well <br />Input Parameters <br />Calculated Paramter <br />Dispersal Field = DF <br />Vadose Zone = bottom of DF to season high groundwater <br />Seasonal High Groundwater = highest groundwater table since 1980 per <br />SJC Flood Control Maps (typically 1983 or 1997) <br />Deep Percolation from Rainfall = Rainfall -Evapotranspiration <br />Other sources of nitrate in 1 -mile radius <br />Number of water wells in 1 -mile radius of site, or service by public water system <br />Date of water well installations at the site, in area <br />Depth of wells, depth of grout seals <br />Within a city Sphere of Influence <br />Number of sewered homes within 1 -mile radius of site <br />CA Irrigation Management Information System (CIMIS) <br />Deep Percolation from Rainfall Data (2014-2018) <br />Station Annual Ave (in) Annual Ave (%) <br />Oakdale (194) <br />Ripon (249) <br />Manteca (70) <br />Holt (248) <br />Staten Island (242) <br />3.29 <br />29% <br />3.12 <br />26% <br />3.62 <br />32% <br />3.72 <br />31% <br />12.6 <br />55% <br />Note: Additional wastewater nitrate (Nw) contribution should be included for the additional wastewater quantity (Q) added for multiplel dwellings or bedrooms over 4. <br />