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For VOCs, the laboratory will use Method 5035 to remove subsamples from the liners/sleeve and prepare the subsamples for analysis. EPA Method 8260B will be used to analyze samples for VOCs; Method 8015B for TPH-C4-10. Samples to be analyzed for the heavier petroleum hydrocarbons (by carbon chain length) will be collected directly from the liners/sleeve and analyzed by Method 8015B. Method 6010B will be used to analyze for arsenic and mercury, and Method 9060 will be used to analyze the soil samples for total organic carbon. In addition to the duplicate samples collected, one trip blank per container (ice chest or cooler) will be carried through sampling and handling protocols as a check on potential diffusion of VOCs from the sample containers. The soil borings will be extended to first groundwater where grab samples will be collected. These groundwater samples will be subjected to the same analyses as those collected from the permanent monitoring wells. Refer to Section F below. The four interior soil borings will be backfilled by grouting with a neat cement grout, cement/sand grout, cement/bentonite grout or bentonite grout. Grout will be emplaced from the bottom to the top of the borehole by means of a tremie pipe or pump to ensure that the borehole is completely filled, and that bridging in the hole has not occurred. Additional grout will be added to the borehole if significant settlement has occurred after the grout is set. The surface will be patched with concrete to match the material, lines and grade of the existing pavement. Soil cuttings will be drummed and kept on site until soil analytical results have been received from the laboratory. The drums will be labeled with generator name, address and contact information; date of initial storage; identification of source (Area and borehole number); other pertinent information. After the soil chemical analyses have been received, the soil and drums will be disposed in conformance with appropriate regulations. F. WELL SAMPLING Well sampling will be scheduled a minimum of 48 hours after development. Purging will utilize a low-flow pumping rate of 250 mUmin (which may be field adjusted, depending upon conditions). Water quality indicators—including pH, temperature, oxidation-reduction potential, electrical conductivity and turbidity—will be monitored throughout the purging process. Purging will continue until conditions are stable—i.e., until the variance between sequential conductivity measurements is 10 percent or less. Purged volumes, water quality measurements, total volume of water removed, any anomalies noted, and times will be recorded on the log sheet, a sample of which is shown in Figure 10. Groundwater samples will be analyzed for • VOCs • TPH-cc • Total arsenic, total mercury and hexavalent chromium(Cr VI)