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GeofoguaI ndmcs lnr. Page 2 Groundwater Monitoring Report Project No 724 2 May 16, 2005 ' The data from the wells that were installed at the site in December 2003 continues to indicate that the plume appears to extend to the east of the site It is not known whether or not ' contaminated properties to the northwest of the site may be contributing to the groundwater plume 1.0 GROUNDWATER MONITORING ' 1.1 Hydrogeology of Site The site's monitoring wells are screened through various levels of the aquifer as shown in ' Figure 13 The wells' construction details are indicated in Table 7 Horizontal Groundwater Gradients Due to there being monitoring well sets at three different depth intervals (water table, intermediate & deep), three different horizontal gradients were calculated, one for each interval The calculated gradients for the April 2005 monitoring event are as follows Water table wells screened 25 to 50 ft bgs 0 0099 ft/ft flowing S67E Intermediate wells screened 42 to 64 ft bgs 0 0051 ft/ft flowing N550E Deep wells screened 65 to 80 ft bgs 0 0022 ft/ft flowing N65°E* *MW-104 was not utilized for gradient determination due to deeper well screen(87 5—90') Figures 2, 3 & 4 show the respective gradient directions for the shallow, intermediate and deep wells, respectively The data for well MW-104 are omitted in Figure 4 contours due the ' well's deeper screened interval, and monitoring wells MW-107, MW-110 and MW-111 are not used for contouring in Figure 3 due to anomalous data It is noted that the data is anomalous compared to data from surrounding wells, but may represent actual groundwater ' levels being affected by the deferring rates of groundwater recharge during this year of high precipitation Additional monitoring will help us determine the duration of this recharge pattern Tables 1, 2 & 3 in Appendix A contain the historical groundwater elevations and ' gradients for the shallow, intermediate and deep wells respectively Figures 5A, 5B and 5C, Groundwater Gradient Rose Diagrams, illustrate the historical range ' of groundwater flow directions for the three respective horizons The groundwater flow direction was easterly for all three aquifer intervals for this monitoring event ' The average elevation of groundwater in the water table wells site was —21 33 feet MSL (below mean sea level) This elevation represents an increase of 3 1 feet since the January 2005 monitoring event The rose diagram included in Figure 5A shows that the water table groundwater gradients at ' this site are consistently towards the east In Figure 5A, arrows labeled 22 and above were