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Former Dolly Madison Workplan Page 3 January 28, 2000 Project No. 2002-1426-02 Task 2 - Field Activities (CPT and Hydropunch Sampling) To assess the vertical extent of petroleum hydrocarbons, Stratus will conduct those activities outlined below. Appendix A, Field Procedures and Practices and Appendix B, Sampling and Analysis Procedures present detailed procedures associated with the proposed activities. The proposed method of assessment involves the use of an electronic CPT advanced in one boring, while a second boring, created by a direct push method, allows for collection of soil and groundwater samples (Hydropunch). This method of assessment was selected because the CPT provides a continuous log of the subsurface material which is then used to determine desired depths for collecting soil and groundwater samples from the adjacent direct-push boring. Additionally, this method does not generate soil cuttings and minimizes disturbance to the surface. The CPT consists of advancing a cone-tipped cylindrical probe (1.7 inches in diameter) into the ground while simultaneously measuring the resulting resistance to penetration. A computer generated CPT log is plotted in the field, providing a continuous log of site lithology. Upon completion of sampling, the CPT hole will be pressure grouted from the bottom of the borehole up. Following the CPT work, soil and groundwater samples will be collected from a separate boring located approximately 3 feet from the CPT boring. Hydropunch sampling equipment will be used to collect the samples at desired depth intervals, based on the continuous log generated from the CPT. The Hydropunch sampler will be pushed approximately 2 feet below the bottom of the borehole and the screen interval exposed to allow for the collection of discreet groundwater samples. Procedures pertaining to the use of the Hydropunch and collection of samples are detailed in Appendix A. Hollow rods (approximately 2 inches diameter) with a modified tip will be pushed into the subsurface to collect soil samples. Upon completion of sampling, the direct-push boring will be pressure grouted from the bottom of the borehole up A total of 2 locations onsite, each consisting of one CPT boring and a direct push boring are proposed. Figure 2 presents the proposed locations. The first CPT will be located adjacent to B1/VW-1, where the former UST was located. The second CPT will be located near B3/MW-2, downgradient from the former UST. The depth of the CPTs will be approximately 120 feet bgs (5 to 10 feet below historical groundwater low) to characterize the vertical extent of impact. A total of 12 soil and 8 water (Hydropunch) samples will be collected from each direct- push boring and submitted for laboratory analysis. This includes one soil and water sample collected from near the soil/groundwater interface. Soil sampling will target finer grained material where residual hydrocarbons may be present. Hydropunch sampling will target coarser material and water-bearing zones. C:\My Documents\STRATUS\Ibc\Stockton\workplan.doc STATUS