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§eofogua(TakwaTnc i Page 6 Soil Groundwater Investigation Report George s Service Project No 425 2 November 30, 19911 The geology as it relates to the analytical data is discussed in the conclusion section below Table 1 in Appendix A contains a full summary of the analytical data and the laboratory data sheets are included in Appendix C Figure 3 shows the average TPH-G concentrations in the top ten feet of each soil boring at the site 3.1.2 Groundwater Sample Analysis Two days after development of the new monitoring wells, groundwater samples were collected and submitted for analysis for BTEX and MTBE and TPH-G range contaminants The results of the groundwater analysis are included as Table 3 in Appendix A The analytical data reports are included in Appendix C In summary, elevated levels of BTEX were detected in MW-105 and MW-202 MW-202 also tested positive for low levels of TPH-G MTBE was not detected in any well MW-107 was non-detect for all analytes 3.2 Site Hydrology On October 19, 1998 the top of casings of the new wells and MW-2 were surveyed Into the USGS benchmark, T-933, by Duane Kimball, licensed land surveyor, No 4379 Figure 6 is the signed map with well top elevations provided by the surveyor A groundwater monitoring event was performed on November 13, 1998 and gradient map is presented in Figure 8 Shallow groundwater gradient is shown to flow N39'E with a slope of 0 0017 ft/ft The intermediate depth groundwater at the site flows N60°E with a slope of 0 0018 ft/ft The report for the November groundwater monitoring event will be submitted shortly Tables 4&5 in Appendix A are summaries of water level elevations, gradient slopes and bearings to date 3.3 Geology and ]Field Observations The following section discusses the subjective field observations and geology documented during this investigation based on the interpretations of the field geologist 0 The shallow geology of the site is predominately silt, sandy silt and silty sand 0 Below approximately 35 feet bgs the geology is appears to be non-continuos from borehole to borehole and is pnmanly alternating layers of clays and sands 0 There are some laterally continuos gravel layers at the site One is at approximately 35 feet and was observed in MW-102, MW-105 and MW-107 The other is at approximately 80 feet bgs and is visible in the boring logs of most of the domestic wells in the area See Appendix B, Boring Logs and Figures 4 & 5, Cross Sections for more information A complete domestic well survey report was submitted on August 25, 1997 Figure 7 is an area map with the locations of domestic wells plotted