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• No dissolved-phase hydrocarbon concentrations have been detected in any monitoring well • since May 1993, except for monitoring wells AW-3 and AW-10 which had maximum TPH-D concentrations of 210 ppb and 190 ppb, respectively). • Free product has not been observed in any well. 4.0 FIELD ACTIVITIES 4.1 DRILLING AND SOIL SAMPLING On May 10, 1994, eleven soil borings were drilled to depths ranging from 24 to 34 fbg. Soil samples were collected at 2.5 foot intervals below the backfill to the total depth of the borings, and at 5 foot intervals above ground water and at 2.5 foot intervals from ground water to the total depth of the boring. Refer to Appendix A for details regarding general field procedures and boring logs. See Figures 3 and 4 for geologic cross-sections showing soil types beneath the site. Soil samples collected during drilling were submitted to a state-certified Iaboratory and analyzed for TPH-G, TPH-D, and benzene, toluene, ethylbenzene, and total xylenes (BTEX). The results of Iaboratory analysis of soil samples are listed in Table 1. Refer to Appendix B for a description of the analytical methods used and copies of the official Laboratory Reports, Quality Assurance/Quality Control (QA/QC) Reports, and Chain of Custody Records. 4.2 FLUID-LEVEL MONITORING AND GROUND WATER SAMPLING On May 2, 1994, fluid levels in Monitoring Wells AW-1 through AW-12 were measured. See Figure 5 for a ground water elevation contour map developed from the May 2, 1994, ground water elevation data. On May 2, 1994, ground water samples were collected from all wells in accordance with standard regulatory protocol. Refer to Appendix A for a description of fluid-level monitoring and ground water sampling procedures. Ground water samples were submitted to a state-certified laboratory and analyzed for TPH-G, TPH-D, and BTEX. The results of ground water sample analysis are listed in Table 2, and are shown on Figure b. Refer to Appendix B for a description of the analytical methods used, and copies of the official Laboratory Reports, QA/QC Reports, and Chain of Custody Records. 4.3 SOIL AND GROUND WATER DISPOSAL Drilling activities on May 9 and 10, 1994, generated approximately 2 cubic yards of soil. Drill cuttings were stored onsite on polyethylene sheeting pending disposal at an approved facility. Approximately 220 gallons of rinsate water generated during drilling activities was stored onsite in Department of Transportation(DOT)approved drums pending disposal at an approved facility. 3