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Kennedy/Jenks Consultants <br /> Collection of Groundwater Samples <br /> The drive casing and soil core tube will be advanced until the water table is reached. <br /> Once the water-bearing zone has been penetrated, the sample barrel and inner rods will be <br /> removed from the borehole. A five foot section of 1-inch-diameter, Schedule 40 PVC <br /> slotted well screen with a slot size of 0.10-inch will be installed in the borehole to facilitate <br /> the collection of groundwater samples. Threaded sections of blank PVC well casing are <br /> then lowered into the borehole inside the drive casing. The drive casing will then be pulled <br /> up to expose the slotted interval of PVC well screen to the water-bearing material. A <br /> groundwater grab sample will then be collected from within the PVC casing with a 1-inch- <br /> diameter Teflon or stainless steel bailer. <br /> Laboratory Analysis <br /> Soil vapor and groundwater samples will be analyzed on site using a Department of Health <br /> Services (DHS)-certified mobile laboratory. All samples will be analyzed for Benzene, <br /> Toluene, Ethylbenzene, and Xylenes (BTEX), as well as total petroleum hydrocarbons as <br /> gasoline (TPH gas). <br /> Site Cleanup/ Residual Management <br /> On completion of soil and groundwater sampling, boreholes will be abandoned with a grout <br /> mixture of Type 11 cement with 4% pure sodium bentonite. The grout will be pumped <br /> through a 1-inch-diameter grouting tube positioned at the bottom of the boreholes, prior to <br /> withdrawing the outer rods. <br /> All investigation-derived residuals will be containerized in 55-gallon drums and left at the <br /> former Cardlock gas station site for disposal by Boettcher Properties, Ltd. <br /> Quality Assurance - Quality Control <br /> QA/QC procedures will include: <br /> • Standard laboratory instrument calibration, consistent with state and federal <br /> standards. <br /> • All downhole sampling equipment will be steam cleaned and washed in a trisodium <br /> phosphate (TSP) solution at the beginning of the day and after removal from each <br /> borehole. <br /> • Background air samples will be collected and analyzed at the start of each day <br /> • All samples will be collected under the supervision of a registered civil engineer. <br /> Letter Report <br /> After receipt of analytical results, Kennedy/Jenks Consultants will prepare a letter report <br /> which summarizes the results of this supplemental investigation. <br /> QAIoda1940549%swkMan.doc 3 <br />