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4celogaal Technics Inc Page 6 Additional investigation Work Plan Cardoza(Main St) Project No 662 2 October 8, 2001 ' investigations will be used and representative groundwater monitoring data The calculations divide up the contaminated zone into a series of layers according to geology A ' cylinder shape is used to estimate the volume of soil that has been impacted in each layer To account for differences in contaminant distribution, an inner core and an outer ring will be used on several of the layers The mass of contaminant in each cylinder is determined by squaring the radius of the cylinder and multiplying by Pi (7c) to determine the area The area is then multiplied by the thickness of the layer to get the volume The volume is multiplied by the density of the soil ' (lbs/ft') then by 0 4536 to convert from pounds of soil to kilograms of soil The contaminant load is then multiplied to this number to give the mass of contaminant in milligrams The contaminant mass in milligrams is then converted to kilograms, which is ' the contaminant mass value you are after I The groundwater value is calculated much the same except that the groundwater contaminant load is multiplied by the volume of groundwater in the pore space of the soil ' The volume of groundwater is determined by multiplying the porosity of the soil times the volume of soil 4.2 Fate and Transport Calculations Fate and transport equations will be conducted to estimate future horizontal and vertical migration of contaminated groundwater Linear groundwater velocity will be calculated for both the upper and lower parts of the aquifer by using the equation in the form of • Vx K/ne x dH/dL ' Contaminant transport velocity will be detennmed for both the upper and lower parts of the aquifer by using the equation in the form of • V,:=VX/R To perforin these calculations the following aquifer parameters will need to be obtained • Dry bulk density • Porosity • Hydraulic conductivity ' From the two equations, estimates will be made on how long it will take for, or if, the plume will impact potential receptors ' 4.3 Intrinsic Bioremediation Parameters Analysis Each site has geologic, geochemical, and hydrogeologrc conditions that are unique and that control the fate and transport of contaminants in the subsurface As the plume spreads and ' migrates, it will alter the natural condition of the vadose zone and groundwater aquifers By monitoring both inside the plume and out, the state of the plume and its tendency to attenuate (i c , undergo reduction of mass of chemicals) on its own can be measured Therefore the risk these chemicals pose to public health and the environment can than be evaluated i