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' Geologica1 Ted ixics lrcc. Page 2 Groundwater Monitoring Report ' Project No 724 2 November 21,2005 ' The data 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 This possibility is being investigated by installing CPT borings-to the east of the subject site ' 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 August 2005 monitoring event are as follows Water table wells screened 25 to 50 ft bgs 0 0016 ft/ft flowing S300E Intermediate wells screened 42 to 64 ft bgs 0 002 ft/ft flowing N89°E Deep wells screened 65 to 80 ft bgs 0 002 ft/ft flowing S49°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 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 or southeasterly for all three aquifer intervals for this monitoring event The average elevation of groundwater in the water table wells site was -2128 feet mean sea ' level (msl) This elevation represents an increase of 005 feet since the April 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 measurements made after November 2000 Since additional wells were installed in ' November 2000, the groundwater direction has had a more southerly component suggesting that the earlier measurements were biased due to the spatial orientation of fewer wells The rose diagram included in Figure 5B shows that the intermediate aquifer gradients at this site