Laserfiche WebLink
i <br /> APPENDIX D <br /> VOLUME/MASS ASSUMPTIONS AND CALCULATIONS <br /> For Dissolved TPH-g <br /> REMAINING HYDROCARBONS <br /> Based on the average hydrocarbon concentration of dissolved TPH-g in ground water samples <br /> reported from grab and quarterly ground water sampling during previous site assessments (Figures <br /> D-3 and D-4), the following calculation for the remaining dissolved petroleum hydrocarbons has <br /> been made. <br /> Assumptions <br /> A roughly drawn volumetric ellipsoid shape is used to represent the remaining laterally and vertically <br /> undefined dissolved volume of TPH-g: <br /> - Half-ellipsoid for Total Zone (concentration of dissolved TPH-g greater than <br /> 50 micrograms per liter (µg/l)) of dimensions : <br /> Major axis : 400 feet - major radial axis: 200 feet <br /> Minor axis : 150 feet - minor radial axis : 75 feet <br /> Vertical axis : 85 feet - vertical radial axis : 43 feet <br /> - Half-ellipsoid with an Inner Zone (concentration of dissolved TPH-g greater than <br /> 1000 µg/1) of dimensions : <br /> Major axis: 300 feet - major radial axis : 150 feet <br /> Minor axis: 70 feet - minor radial axis : 35 feet <br /> Vertical axis : 45 feet - vertical radial axis : 23 feet <br /> - Volume of the half-ellipsoid Outer Zone (concentration of dissolved TPH-g between <br /> 50 4g/1 and 10,000 gg/I) = Total Zone half-ellipsoid volume - Inner Core half- <br /> ellipsoid volume <br /> The volume of the ellipse (Ve,,;P9L) = 4/3 • rc • pma,or • k;aor • lten;ca,, where: <br /> ka j , = major radius; Itz1,;,,0, = minor radius and R,,,,,,,; = vertical radius <br /> Volume of half-ellipsoid Total Zone: <br /> VzutPse TOTA ZONE = (4/3 • n • 200 ft • 75 feet • 43 feet ) / 2 = 168,861 ft' <br />