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1 .0 Introduction/Previous Work The subject property has been under investigation since 1987 . Both soil and groundwater contamination investigation has been performed at the site and was summarized in a report to the Regional Water Quality Control Board ;RWQCB) dated July 21, 1988, and prepared by Groundwater Technology, Inc. (GTI ) . This report served as the basis for a Soil Remediation Workplan dated February 6, 1989, which was approved for implementation by the RWQCB on February 17 , 1989 . This plan called for the z installation of a soil venting (vapor extraction) system. Both of these reports, and the RWQCB letter of approval are contained in Appendix A. These reports include all relevant background data for the site and are included to insure the completeness of the County' s files. The July 21, 1988 report indicated the presence of groundwater contamination. In January of 1989, four additional monitoring wells were installed at the site. To date a summary report on the well installation has not been prepared. The locations and boring logs of these wells are contained in Appendix B. 2.0 Workplan Rationale/Objectives A review of the GTI soil remediation workplan by WaterWork resulted in a reconsideration of the soil venting approach. Similar reservations were indicated in the RWQCB letter approval which questioned the system ' s ability to remediate low permeability silt and clay sections and requested verification ( see Appendix A) . Because the plan was based on a single boring, the extent of contamination and the site stratigraphy were not adequately defined . Therefore, the primary objective of the present workplan is to properly define the lateral and vertical extent of soil contamination by logging and sampling three additional deep borings. The data from these borings may be used to prepare a revised soil remediation workplan. In addition, a secondary objective is to establish existing groundwater conditions by monitoring and resampling the seven monitoring wells on site. This data will serve as input to the Problem Assessment Report which is still in progress. 3 .0 Proposed Soil Sampling Locations and Methodology: To assess the contribution of the former u/g gasoline storage tanks to soil contamination at the project site, WaterWork proposes to drill three additional soil borings to supplement the existing lithologic and geochemical data from eight deep borings and 10 shallow borings. Soil borings will be advanced to determine the vertical and lateral extent of soil contamination beneath the former storage tanks. The proposed boring locations are shown on Figure 1 . Borings will be advanced to a minimum depth of 50 feet below = 1