Laserfiche WebLink
�� h ►%�i RN.. A,RAMEN.0 <br /> SREVIEW DRAFT <br /> 9 Addendum Letter to Mr. Harlan Knoll <br /> August 31, 1990 <br /> Page 3 <br /> PILOT STUDY METHODOLOGY <br /> The three major factors which control an in situ soil venting <br /> operation are: 1) the contaminant vapor concentrations; 2) the vapor <br /> flow rate and 3) the vapor flow path relative to the location of the <br /> contamination. The proposed pilot study calls for the installation of <br /> four wells at the former UST site. One of these would be installed over <br /> the center of the former UST site, while the remaining three wells would <br /> be located at predetermined distances out along one or more rays from <br /> the well at the UST site. Potential well configurations are shown in <br /> Figure 5, Attachment I. By installing the four wells and conducting the <br /> pilot study the following information would be obtained: <br /> 1) Qualitative analysis of contaminant vapor concentrations in soil <br /> samples obtained at five foot intervals throughout the boreholes <br /> as well as quantative analysis of selected samples. Since <br /> temperature is a controlling factor in soil vapor, the temperature <br /> of soil samples from one complete column will be measured in the <br /> field upon sample retrieval . <br /> 2) The steady state vapor flow rate along different vapor <br /> extraction vectors. This will be accomplished by utilizing <br /> alternate wells as the extraction well and varying the number and <br /> location of air intake wells that are open for air intake. Air <br /> flow will be measured using calibrated pitot tubes, rotameters, or <br /> equivalent. Pressure reading will be made at all wells using <br /> magnahelic gauges or manometers. These measurements will also <br /> determine the radius of influence of the extraction well . <br /> 3) Quantative analysis will be conducted on vapor samples at each <br /> extraction wells to determine the quantity of hydrocarbons which <br /> are extractable along different vapor extraction vectors. These <br /> analyses will allow the calculation of the project duration and <br /> end residual contamination. <br /> Biodegradation <br /> Bacteria are a widely used methodology for the remediation of <br /> hydrocarbon contaminated soil and groundwater. Often this involves the <br /> seeding of soil with bacteria and nutrients; however, the necessary <br /> bacteria are generally present in the subsurface soil although at low <br /> populations. By increasing the available oxygen in the subsurface, it is <br /> feasible that the bacteria population will increase and consume the <br /> available hydrocarbons as a source of nutrients. <br /> r <br />