Laserfiche WebLink
Varra Coal Ash Project <br /> Selenium Calculation <br /> This spread sheet calculates the steady slate concentration at a point of compliance <br /> well located at a distance (x) down-gradient of the source area. The calculations and <br /> methods are describe in ASTM-38 RBCA. <br /> Spread Sheet Calculations Enter <br /> Enter Porosity (sand 0.3, silt 0.35, clay 0.4) 0.27 <br /> Enter hydraulic gradient[tt/ft] 0.0023 <br /> Enter hydraulic conductivity [cm/s] 0.044 <br /> Enter first-order degradation constant 0 <br /> Enter distance (x) to point of compliance[ft] 50 <br /> Enter source width (perpendicular to flow in the horizonal plane) [ft] 100 <br /> Enter source width (perpendicular to flow in the vertical plane[ft] 7 <br /> Enter source area concentration (mg/L) 0.015 <br /> a,= longitudinal dispersivity,[cm] = 0.lox= 610 cm <br /> ay=transverse dispersivity,[cm]= a,/3 203.3333 cm <br /> a,=vertical dispersivity,[cm] = otd20 30.5 cm <br /> Ground water velocity [cm/s]= 0.000375 cm/s <br /> Ist error function 1.368857 <br /> 2nd error fuction 0.247406 <br /> erf(rI)=error function of evaluated for lst function = 0.952884 <br /> erf(rI)=error function of evaluated for 2nd function = 0.27382 <br /> Steady State Concentration fC(x) at <br /> Point of Compliialnrce=r J <br /> r l 3.91 ua/L <br /> C(x) = Caexpj nx Ll— 1+4Aa"J} erfL � erf[ a�=x <br /> a. u JJJI 4 a,x 4 a�x <br /> erf(n) = I- expl —J l X <br /> C (x) = dissolved phase concentration along centerline(x, y= 0, z =0) of dissolved plume [g/cm'-H20] <br /> C s ,� = dissolved phase concentration in dissolved plume source area [g/cm'-H2O] <br /> x=distance along center line from down-gradient edge of dissolved plume source (cm) <br /> %= longitudinal dispersivity, [cm] = 0.10x <br /> X=first order degradation constant[d'] <br /> u = Ki\� ground water velocity [cm/d] <br /> S„= source width (perpendicular to flow in the horizonal plane[cm] <br /> Sd= source width (perpendicular to flow in the vertical plane) [cm] <br /> aY= transverse dispersivity,[cm]= a,/3 <br /> a,=vertical dispersivity [cm] = otd20 <br /> erf(rI)=error function of evaluated for value rl <br /> Revised on March 18,1997 <br /> Page 1 <br />