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Mr. Don O. Culbertson Proposal P95-06056 June 29, 1995 Page 4 accompany the samples throughout transport to the laboratory. Soil samples will be submitted for chemical analysis from at least two depths from each boring. The sample collected from the capillary fringe and the sample with the highest concentration of volatile vapors (based on a field FID) will be analyzed. Additional soil samples may be submitted for chemical analysis from each boring if they display evidence of significant impact by petroleum hydrocarbons. In addition, a soil sample collected from the bottom of the boring completed next to Area 4 to assess the vertical extent of impacted soils will be submitted for chemical analysis. After collecting the soil sample from the capillary fringe, the rods will be driven below the water table, then slightly withdrawn which allows groundwater to flow into the resulting hole. The water will be drawn to the surface and collected for analysis. The existence of floating product can also be detected using this methodology. After collecting a groundwater sample the rods are removed from the ground and the hole is sealed with a cement/bentonite grout. Sampling rods will be steam cleaned before drilling each hole. Soil sampling devices will be cleaned with a mild detergent and rinsed in clean water before collecting each sample. New tubing will be used for each water sample to prevent possible cross contamination. After completing the borings, their locations will be indicated with flagging and surveyed to accurately locate their position and elevation. The survey information along with depth to water level measurements made during the Geoprobe survey may be used to assess the preliminary groundwater gradient and flow direction. This information along with the results of the soil and groundwater sampling will be useful in selecting locations for the monitoring wells. Task 3 Monitoring Well Installation, Development, and Sampling During this phase of field activities, EMCON will supervise the completion of three groundwater monitoring wells. The proposed locations of the wells, which are indicated in Figure 5, may be adjusted based on the results of the soil and groundwater sampling program. Subtask 3.1 Monitoring Well Installation Soil borings will be completed using hollow-stem auger drilling equipment. During completion of the borings, one boring will be continuously cored beginning at approximately 5 feet bg and extending to the bottom the boring. The borings will be logged in the same manner as those completed during the Geoprobe survey and detailed boring logs will be presented in the final report. After each boring is completed, groundwater monitoring wells will be installed in the borings. The wells will be constructed with 2-inch-diameter, flush-threaded, schedule 40, FRF/H:\wp\proposaN39506056.wp5-95 gtf:1