Laserfiche WebLink
Pilot Testing Report and Conceptual Corrective Action Plan July 15, 1994 <br /> Manna Pro, 4004 South EI Dorado, Stockton, CA 10 <br />' the various isoconcentration contours The sod mass estimates were performed at four depth <br /> intervals surface to 20 feet, 20 to 35 feet, 35 to 40 feet, and 40 feet to 50 feet The volume of soil <br />' within each isoconcentration contour was calculated based on the calculated areas multiplied by the <br /> thickness of the interval Ultimately, the mass of TPH-G/TPH-D compounds in the sod interval was <br /> calculated using the average concentration present between the isoconcentration contours The <br /> volume and mass estimates are calculated only to the extent that isoconcentration lines could be <br /> practically drawn for each interval <br /> An estimated 31,134 pounds of adsorbed-phase TPH-G/TPH-D hydrocarbons are estimated present <br />' in the unsaturated zone soils The mass estimate for TPH-G/TPH-D adsorbed in the soil is <br /> summarized in the calculations presented in Appendix C <br /> 42 Dissolved-Phase Hydrocarbons <br /> Dissolved-phase hydrocarbons are those hydrocarbons solubilized in the groundwater Variables <br /> that significantly affect the mass of dissolved-phase hydrocarbons include mass of hydrocarbons <br /> released, adsorptive capacity of the soil, contaminant solubility coefficients, and permeability of the <br /> subsurface strata <br /> 4 2 1 Distribution of Dissolved-Phase Hydrocarbons <br />' The distribution of dissolved-phase hydrocarbons in the groundwater was determined through <br /> groundwater analysis Groundwater samples were collected from wells MW-1 through MW-10 on <br />' February 3, 1993 Isoconcentration maps of groundwater TPH-G concentrations are presented in <br /> Figure 10 TPH-D has not been detected in groundwater <br />' The distribution of dissolved-phase TPH-G (Figure 10) appears to follow the general direction of the <br /> groundwater gradient (Figure 5) The dissolved-phase TPH-G plume is centralized in the area of the <br />' former USTs and appears to migrate to the north <br />' 422 Dissolved-Phase Hydrocarbon Mass Estimate <br /> The mass estimates of dissolved phase hydrocarbons present at the site were prepared based on <br />' the TPH-G isoconcentration map Using an aquifer thickness of 10 feet, and an estimated porosity <br /> of 25 percent, approximately 335 pounds of TPH-G were estimated to be dissolved in the <br />' 2819R034 070 <br /> GROUNDWATER <br />' ELjq TECHNOLOGY, INC <br />