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r Jam` E -W,- used, detailed sampling and decontamination procedures and information specific to each site nay be found in Appendix C. _. Appendices C, D and E also present monitor well logs, groundwater sampling logs and chain-of-custodies, respectively. 4.0 Site Geology and Hvdre,geoloav Little lateral continuity was exhibited between the three monitor well boreholes. The unsaturated sediments at the site consist of interfingered silts and clays with occasionally discontinuous sand lenses. The saturated sediments were typically sandier than the overlying materials. Groundwater was encountered at approx- imately 45 feet BGS. Saturated soils at MW-2, being dominated by silts and clays to about 60 feet BGS, appeared to contain much less sand than the other locations. Characterization of the lithologies was based on cuttings return (poor in saturated formations) and on response of the drill rig during drilling. Appendix D presents the monitor well logs which contain both lithalogic information and well construction details. Water yield at 14W-1 dnd MW-3 was at least 10 GPM, the maximum flow rate of the pump used for development. These wells also cleared quickly during development, indicative of predominantly sandy material. MW-2 was able to sustain a flow rate of approxi- mately 5 GPM and cleared somewhat more slowly than either MW-1 or MW-3. This performance is consistent with the iithologic infor- matian obtained during the drilling of the wells. Groundwater level data was obtained on August 19, 1988, during the water sampling. after adjusting water levels to a common reference elevation, the water level elevations were plotted on a scaled site map and groundwater contours were computed. From this information, it appears that groundwater flow across the site is to the northwest (Figure 2) . Consequently, Mir-1 is downgradient, MW-2 is cross gradient and MW-3 is upgradient of the excavated area. Appendix E "resents the pumping rate data and water level data for each welL. 5.0 Analytical Results All samples collected at the site (subsurface soils, development water and post-development groundwater) were submitted to the WESTON Analytics' Stockton, California laboratory. Each sample was analyzed for aromatic volatile organics (_EPA method 8020 for -- -- - sods-and-EPA-method_602 for-water)-and-total petroleum hydrocar bons (EPA method 8015 modified for diesel) . The former analysis includes quantification on benzene, toluene, ethyl benzene, the _ 4 _