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C,eologual Technics Inc Page 2 ' Groundwater Monitoring Report Project No 425 2 May 12, 2003 • TPH-G concentrations in MW-1, MW-4 and MW-5 have shown an increasing trend over the history of the site MW-4 and MW-5 showed slight decreases in TPH-G concentrations this quarter Only one of the deeper screened wells (MW-102) was analyzed this quarter and was non-detect This is the tenth consecutive event that this condition has been documented 1.0 GROUNDWATER MONITORING 1 1 Hydrology of Site I 11 Horizontal Groundwater Gradients The average water table elevation at the site on March 21, 2003, was 73 39 feet above mean sea level This represents a decrease of 0 24 feet since the December 2002 event The water table groundwater gradient was 0 0021 ft/ft flowing N85°E 1 The average groundwater elevation in the intermediate depth wells (MW-102, MW-105 & MW-107) for the March 2003 monitoring event was 73 29 feet above mean sea level and the M intermediate depth groundwater gradient was 0 0014 ft/ft flowing N38°E This is, historically, the gentlest slope calculated at the site using the intermediate monitoring wells ' A review of the groundwater gradients shows that the predominant groundwater flow varies from north to northeast with the slope ianging from 0 0009 up to 0 0044 ft/ft in the water table wells Table 1 of Appendix A summarizes the water table groundwater gradients and levels to date, and Figure 2 illustrates the March 21, 2003, groundwater gradient The predominant groundwater flow is to the east--northeast with the slope ranging from 0 0014 to 0 0270 ft/ft in the inteimediate wells Table 2 of Appendix A summarizes the intermediate ' groundwater gradients and levels to date, and Figure 3 illustrate the March 21, 2003, groundwater direction and gradient in the intermediate wells Table 2 also summarizes the groundwater level data from the deep well, MW-202 ' The historical water table and intermediate groundwater gradients are included in Figures 4 & 5- Shallow and Intermediate Rose Diagrams 1.1.2 Vertical Groundwater Gradients Vertical groundwater gradients were calculated using monitoring wells MW-2/MW-102 (shallow/intermediate well pair) and monitoring wells MW-102/MW-202 (intermediate/deep well pair) During the March 21, 2003 groundwater-monitoring event, the vertical groundwater gradient in the shallow/intermediate well pair was in an upward, positive, direction with a magnitude of 15 6 times that of the water table horizontal gradient `T he i