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APPENDIX F <br /> TOTAL PETROLEUM HYDROCARBON-GASOLINE IMPACTED GROUND WATER <br /> VOLUME ASSUMPTIONS AND CALCULATIONS <br /> Sierra Lumber(Case No. 1) <br /> 375 West Hazelton Avenue, Stockton, California <br /> Volume of TPH-g Impacted Ground Water Pre-Remediation: <br /> Assumptions: <br /> • The distribution of maximumsolved hydrocarbon concentrations on the site canbe approximated <br /> by an elliptical cylinder(Figur;the distribution can be separated into four contoured areas(i.e. <br /> 100,000 µg/1, 10,000 µg/1, 1,000 µg/1 and 50 µg/1). <br /> • The effective porosity of soil at the site is estimated to be 40% (i.e. silt, silty sand and fine sand). ? <br /> • Data collected from the ground water sampling events are representative of the maximum dissolved <br /> TPH-g site conditions prior to remediation activities. <br /> • The thickness of dissolved plume is estimated to be between the average depth to ground water at <br /> the site and the bottom of the most impacted monitoring well screen intervals(i.e. 20 feet). <br /> The area of an ellipse cylinder can be used to illustrate the shape of the dissolved TPH-g plume, and <br /> calculated by the formula: <br /> Ae=(long radius, a)(short radius,b) (a) <br /> 1) For the estimated 100,000 µg/1 ellipse cylinder, a=20 ft,b = 16 ft,and thickness c=20 ft <br /> Utilizing TPH-g data from wells MW-2,MW-4A and the 100,000µcontour line(Figure 9),therage <br /> pre-remediation TPH-g concentration is estimated to be 136,667 ug/1(equivalent to 0.000136667 grams per <br /> milliliter). A ml is very nearly equivalent to a cubic centimeter of water, which by definition equals one <br /> gram, this concentration is nearly a unitless number. <br /> The area of the ellipse is given by: A100000=x(20)(16)= 1,005.3 ft' v <br /> The volume of the ellipse cylinder is given by: V100000=A10000 x c = 1,005.3 ftz x 20 ft =20,106 W ✓ <br /> Water occupies the porosity in the soil,which is estimated to be 40%of the soil volume,so the total volume <br /> of water in the saturated portion of the ellipse is approximated by: V100000=(0.40)(20,106 ff)= 8,042 W <br /> One fe is equal to 7.48 gallons, so the volume of the water in the ellipse is given by: <br /> V100000=(8,042 W)(7.48 gal/ft)=60,154 gallons <br /> One gallon of water weighs 8.337 lbs/gal, so the mass of the water in the ellipse is given by: <br /> M100000= (60,154 gallons)(8.337 lb/gal)=501,505 lbs p`- <br />