Laserfiche WebLink
?-20-1997 8:45F�.f FROM P. 5 <br /> Page 4 <br /> .' - _tileleyco <br /> March. 19. 1997 <br /> calculations and assumptions am as follows: <br /> AW x Nw I- + r <br /> AW + r <br /> f <br /> Where: <br /> 1Y`= c4.lculated nitrate concancrazior in groundwater resulting from domestic sources and <br /> precipitation - mg/l, as N <br /> A = number of dwelling units per acres on septic tanks (unit/acre) <br /> W = annual wastewater loading per dwelling unit per acre !inches} = 2.0 inct:es(based on 150 <br /> gpd/residence) <br /> I <br /> N.� = nitrate concentration of nitrified leachifield effluent (mg/1) = 40 n:gr'1 to EO mgil. :z, N <br /> a <br /> D = percent denitrification of leachfield cffiuent =0.25 to 0.10 <br /> r = annual deep percolation of precipitation (inches) = 3.0 incites %based on 13.5 inches <br /> Precipitation. 2 inches runoff and 8.5 inches ET) <br /> Nb = backgz-ound nitrate concentration of the deep percolating precipitation - m9/1 = 2.2 mg/l. <br /> as N(per KC einfelder) <br /> Low Estimate: <br /> N, = 1.0 2.0) (AP—M-91-1) (1. -0.25 +-(-3.0) 2.2 mg!) <br /> it.0) t2.0) +3.0 <br /> N_ = 50 +6.6 = 66.6 = 13.3 mg/I nitrate, as N <br /> + 3 5 <br /> Higiz Estimate: <br /> (1,0) -0 60 in /11 (i - 0.10) f 1.1' (2.2 m /l) <br /> (1.0) (2.0) + 3.0 <br /> k <br /> L <br /> F <br /> n <br />