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rs � 2.2 Soil Boring and Sampling Boreholes will be advanced using a truck mounted, 8-inch diameter hollow-stem auger drill rig and shall be advanced to a minimum of 10 feet below the ground surface. Boring logs describing the encountered soil shall be prepared during the drilling at the site. The first borehole shall be advanced through the center of the backfilled pit to determine whether a concrete tie-down slab is present. Boreholes shall be advanced along the perimeter of the backfilled pit (one on each side). The proposed soil boring locations are shown on Figure 1. Soil samples from the boreholes shall be obtained from native soils adjacent to or immediately below the bottom of the concrete tie-down slab. If residual hydrocarbons are encountered in the soils beneath the tie-down slab, the boreholes shall be advanced and additional soil samples shall be obtained in 5-foot intervals to characterize the extent of the residual hydrocarbons in the soil. Soil samples shall be obtained from the undisturbed soil below the lead auger flight using a hammer driven, 18-inch long, split tube sampler fitted with three, 6-inch long by 2-inch diameter, brass tubes. Soil samples shall be prepared/preserved in the field for subsequent laboratory analysis. The ends of each sample tube shall be capped with Teflon film and plastic end caps and shall be sealed with tape. The samples will then be labeled and placed in a cooler with ice packs to cool the samples to a maximum temperature of 4°C. The cooler containing the samples shall be transported to a State-certified hazardous materials testing laboratory. Chain of custody procedures will be observed. The Standard Operating Procedure for manual soil sampling is included as Appendix A. 2.3 Laboratory Analytical Procedures The soil samples obtained from the site shall be transported with chain-of-custody documentation to a State-certified hazardous materials testing laboratory for analysis. Samples shall be analyzed for TPHd in accordance with EPA method 3550/8015 and BTEX in accordance with EPA method 8020. A 24-hour turnaround will be requested for analysis of the samples. 2.4 Site Cleanup At the completion of drilling, the boreholes shall be filled with grout in accordance with San Joaquin County regulations. Soil cuttings produced from the boreholes will be temporarily placed on and covered with plastic sheeting. Augers and sampling equipment shall be steam cleaned prior to utilization and at the completion of the investigation. Steam cleaning water shall be contained and temporarily stored on site in 55-gallon drums. The methods for disposal of the soil cuttings and the steam cleaning water will be determined upon receipt of the analytical results. 4185\CB W I\SPRLNT.WPMSEP94 3