SITE INFORMATION AND CORRESPONDENCE_CASE 1

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APPENDIX F DISSOLVED TPH-g VOLUME ASSUMPTIONS AND CALCULATIONS PAGE 2 OF 7 Multiplying Mi00000 by the hydrocarbon concentration yields the approximate mass of dissolved hydrocarbons in the saturated portion of the ellipse: Mi00000(501,5051bs)(0.000136667)=68.5 lbs of dissolved TPH-g Dividing M,00000 by the weight of one gallon of gasoline,6.25 lbs/gallon,will yield the approximate volume of TPH-g dissolved into the ground water of the inner ellipsoid: Vi00000=(Mm0000)/6.25lb/gal)=68.5/6.25 lbs/gal= 11 gallons of dissolved TPH-g 2) For the estimated 10,000 µg/1 ellipse cylinder, a=38 ft,b= 31 ft, and thickness c=20 ft Utilizing TPH-g data from well MW-1, the 100,000 µg/1 contour line and the 10,000 µg/1 contour line (Figure 9), the average pre-remediation TPH-g concentration is estimated to be 59,667 ug/l(equivalent to 0.000059667 g/ml).A ml is very nearly equivalent to a cubic centimeter ofwater,which by definition equals one gram, this concentration is essentially unitless. The area of the ellipse is given by: A10000=7r(38)(3 1)= 3,701 ft- A100000=2,695.7 fP The volume of the ellipse cylinder is given by: V,0000=Ai0000 x c=2695.7 W x 20 ft =53,914 ft' Water occupies the porosity in the soil,which is estimated to be 40%of the soil volume,so the total volume of water in the saturated portion of the ellipse is approximated by: V,0000=(0.40)(53,914 ft') =21,566 ft' One ft' is equal to 7.48 gallons, so the volume of the water in the ellipse is given by: V10000=(21,566 ft')(7.48 gal/ft') = 161,314 gallons One gallon of water weighs 8.337 lbs/gal, so the mass of the water in the ellipse is given by: Mi0000= (161,314 gallons)(8.337 lb/gal)= 1,344,875 lbs Multiplying Mi0000 by the hydrocarbon concentration yields the approximate mass ofdissolved hydrocarbons: M,0000( 1,344,875 lbs)(0.000059667)=80.2 lbs of dissolved TPH-g Dividing M10000 by the weight of one gallon of gasoline,6.25 lbs/gallon,will yield the approximate volume of TPH-g dissolved into the ground water of the inner-middle ellipsoid: V10000=(MI0000)/6.251b/gal)=80.21bs/6.25 lbs/gal=12.8 gallons of dissolved TPH-g