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Water levels in the South Tracy#1 production well typically recovered to an elevation between 20 and 40 feet(msl)each winter until 2001,when increased pump operation made the measurement of static water levels difficult. Upon Teichert's initiative, plant staff have measured static and pumping water levels in �I the South Tracy#1 well more frequently since late 2001,and these supplemental data are provided in the R j Appendix. Water levels in the South Tracy#3 production well are also monitored at a higher frequency. However,the sounding of water levels below a depth of approximately 273 feet has not been successful due to an obstruction at this depth,likely due to a problem with the well's access port. As a result,any �i water levels below a depth of approximately 273 feet(i.e.,-28 feet,msl)erroneously appear as a constant V water level on this well's hydrograph(see Figure 4 and the we'll's hydrograph in the Appendix). The Petz irrigation well,which is located west of the Teichert Vernalis plant,is completed in both the -i shallow and deep zones of the underlying aquifer system, and its water level hydrograph reflects a composite of these shallow and deep zones(Appendix). The early water level record of this well(prior F. to 2000) shows groundwater level elevations between those observed in the discussed shallow and deep wells in the area. Similarly, seasonal fluctuations prior to 2000 appear to be a composite of observations made in the shallow and deep network wells. Specifically, seasonally high water levels in this well rose from72.46 to 86.58 feet(msl)between March 1994 and 1998,with seasonal fluctuations of almost 15 feet. Since then,water levels have been very similar to those observed in the shallow network wells. Contours of equal groundwater elevations prepared with data from the shallow network wells show that I F the general direction of groundwater flow during times of seasonally high water levels was typically to the east-southeast and east. This includes the first monitoring event in spring 1994 with comparatively high water levels (Figure 5) and the period of the highest historically recorded groundwater elevations in E spring 1998 (Figure 6). The water level elevations in spring 2000 were relatively low compared to groundwater conditions observed in previous spring seasons,however,the predominant direction of flow was also to the east-southeast(Figure 7). More recently, easterly and east-northeasterly groundwater flow directions have been observed. This includes conditions observed in spring 2002 (Figures 8),when overall groundwater elevations were very similar to the spring 2000 elevations. The lowest overall spring groundwater elevations to date were I observed in May 2006,and the predominant direction of flow was to the east(Figure 9). E I. 3.2 Groundwater Quality The electrical conductivity(EC) of samples retrieved from the shallow network wells(Hall and Faulkner domestic wells)typically ranges between 900 and 1,000 gS/cm and has been stable during the period of record(Figure 10). The EC of samples retrieved from the deep network wells typically ranges between 800 and.950 gS/cm and has also been stable during the period of record. Samples retrieved from the Granite#3 well(sampling commenced in 2006 as a replacement for the vandalized Brown's#1 well)had a mean EC of 1,011 gS/cm in 2006. Table 3 summarizes the 2006 analytical results. The complete water quality record is provided in Table 4. Laboratory reports and field notes are provided in the Appendix. Time series plots of major cation concentrations(sodium,calcium,and magnesium)and anion concentrations(bicarbonate, chloride, and sulfate)prepared for the individual wells are in agreement with the EC measurements and reflect stable hydrochemical groundwater conditions(Figures 11 to 17). Concentrations of major cations and anions were averaged over the period of record and plotted in milliequivalents per liter(meq/L). The plot shows that calcium, sodium, and bicarbonate are the most significantly i prevalent ions in both the shallow and deep zones(Figure 18). Shallow groundwater has ii greater chloride concentrations than deep groundwater and its hydrochemical facies is of Ca-Na/HCO3-Cl type. Deep groundwater has significantly greater sulfate concentrations than shallow groundwater and its LUHDORFF & 5CALMANINI CONSULTING ENGINEERS 5