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1 <br /> At such time as uncertified analyses indicate that the <br /> excavator reaches the boundaries of the plume and/or it becomes <br /> unfeasible to excavate further (e.g. upon encountering a <br /> significant obstruction such as a subsurface utility, a building, <br /> or roadway) samples would be acquired from the floor and <br /> sidewalls of the excavation and submitted for certified <br /> laboratory analyses . Each soil sample would be obtained from <br /> ' an undisturbed block of soil brought to grade within the <br /> excavator bucket. After removing the top 1 "-2" of soil within <br /> the bucket, a clean brass sampling tube 1 . 9 inches in diameter <br /> by 6. 0 inches in length would be driven into the remaining soil <br /> ' until completely filled with consolidated material . Promptly 1 <br /> upon removing the sampling tube from the soil , the ends of each <br /> tube would be covered with teff ds fitted with lastic <br /> end caps, and wrapped with lack electrical t marked, and <br /> placed on blue ace pending ranspor to a certified analytical <br /> laboratory under chain of custody. Samples thus acquired would <br /> be analyzed for TPH-D, TPH-G, BTX&E, and Total Lead using the <br />' aforementioned EPA analytical methods. <br /> Contaminated soil which may not be safely or cost-effectively <br />' excavated, and groundwater containing significant concentrations <br /> of hydrocarbons will be treated using in-situ bioremediation <br /> technology described within Appendix "B" . <br /> If wells are required for past-remediation compliance monitoring <br /> of groundwater, it is proposed that three wells be installed <br /> at locations appropriate to the configuration of the contaminant <br />' plume, probable locations of former underground tanks, and <br /> direction of groundwater flow. Wells will be advanced 10-15 <br /> feet below first encountered groundwater. Soil samples collected <br /> beneath the water table will be assessed for lithologic <br /> characteristics only. Construction of these wells will be in <br /> accordance with protocol set forth within Appendix "C" , attached. <br /> Following a 24 to 48 hour period for stabilization of ground- <br /> water, static water elevation will be measured and background <br /> groundwater characteristics ( i .e. pH, temperature, and <br /> conductivity) determined. The wells will then be developed <br /> using a surge block. Subsequent to surging, the wells will <br /> be developed using a hand pump until the water as relatively <br /> t sediment free; and pH, temperature, and conductivity are stable. <br /> Groundwater samples will be collected within a clean teflon <br /> or polyethylene bailer lowered into the well to a point <br /> immediately below the groundwater surface. Each sample thus <br />' acquired would be promptly transferred into two one-liter amber <br /> glass sample bottles and three Volatile Organic Analysis (VOA) <br /> vials, fitted with a teflon-lined screw cap, marked, and placed <br />' on blue ice for transportation to the certified laboratory <br /> 4 . <br />