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KI_EINFECDER <br /> the selection of other <br /> parameters.were based on previous studies by our firm as well <br /> as a report dated March 19, 1997 by Questa Engineering Corporation and authored by <br /> Mr. Norman Hantzsche. <br /> N,� = Average calculated nitrate-nitrogen in groundwater resulting from domestic <br /> sources and precipitation - mgll, as N. <br /> I = Volume rate of wastewater entering the soil averaged over the gross <br /> developed area. Total discharge into the new system is 1,881 gal/week or <br /> 97,812 gal/yr. This figure converts to 97,812 divided by 7.48 gal/ft3 = 13,076 <br /> ft3/yr. <br /> This volume <br /> of wastewater Is spread out over an area equal to 4.91 acres <br /> (43,500 ft2/acre) = 213,585 ft2. <br /> �a <br /> 3 <br /> I equals 13,076 ft /yr = .0612 ft/yr = .73 inches/yr <br /> 324,585 ft� <br /> NW = Nitrate concentration of nitrified leach-field effluent (mg/1) = 85 mg/I <br /> ((Hantzsche and Finnemore (1992) based on - commercial uses and per <br /> discussions with SJC/EHD.) <br /> D = Percent denitrification of leachfield effluent = 0.3 percent (0.1 to 0.35 percent <br /> typical per Hantzsche and Finnemore (1992). 0.3 selected given the fine- <br /> grained soil encountered in our borings and the depth to groundwater. <br /> fit R - Annual deep percolation of precipitation (inches) = 9.45 inchesre resentin <br /> ( p g <br /> 70 percent of the average annual rainfall of approximately 13.5 inches. The <br /> remaining 30 percent of rainfall is assumed to drain off-site into natural or <br /> manmade drainages or be lost to evapotranspiration.) <br /> # Nb = Background nitrate nitrogen concentration of rainfall recharge at the water table <br /> f i = 0.5 mg/l (per Technical Memorandum, Hydrologic and Soil Investigation for <br /> the Chico Urban Area, page 6, Dames and Moore, April 1996) <br /> Our calculation is as follows: <br /> Nc = 0.73(85)(1- 0.3) + 0,5(9_45) = 43.4 + 4.73 = 4..73 mg/l as N <br /> 0.73 + 9.45 10.18 <br /> As a matter of interest, even if the expected flow double from 1,881 gal/week to 3,762 <br /> !t <br /> gal/week, causing "I" = 1.46, the increase in N,,would still be below the state standard. <br /> E Nr = 1.46(85)(1- 0.3)0.5(9.45) = 8.4 mg/I as N <br /> - <br /> 1.46 + 9.45 <br /> 56915.G011ST05RI123 August 30,2005 <br /> ©2005 Kleinfelder,Inc. Page 6 of 8 <br />