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.� 4.8 Hydrology and Water Quality ` Property)is relatively shallow and represents unconfined groundwater conditions at the proposed project site while the onsite groundwater well 4S/6E-04N01 and near-vicinity confined well 4S/6E-04H01 (Barnes Property)represent deeper confined groundwater conditions. TABLE 4.8-2 GROUNDWATER WELLS IN THE PROJECT VICINITY INCLUDED IN THE DWR DATABASE Aquifer Distance from the Direction from the State Well Number Well Depth(Feet) Classification Project Site(Feet) Project Site 4S/6E-04N01 630 Confined Onsite Onsite (Costa Property) 4S/6E-05A01 N/A Unconfined 100 West 4S/6E-04H01 470 Confined <150 North (Bames Property) 4S/6E-10E01 770 Confined 300 Southeast 4S/6E-08R01 310 Confined 1,200 Southwest 4S/6E-05G01 530 Confined 1,400 West 4S/6E-08L02 N/A Confined 1,500 West 4S/6E-09B01 N/A Confined 2,200 South 4S/6E-10R01 250 Unconfined 5,280 Southeast ' All wells listed are in Township 04 South,Range 06 East. ° Condor Earth Technology,1992. N/A Data not available. SOURCE: MWA and ESA,1993. The hydrograph for well 4S/6E-5A01 is shown in Figure 4.8-4.The depth to ground water in this well has fluctuated between 85 feet and 110 feet below ground surface during approximately 40 years of recorded data and based the hydrograph, the 40-year average depth to water is approximately 97 feet below ground surface.The fluctuation of water depth at this well appears to correlate seasonally with precipitation and over longer term periods,to climatic conditions such as the drought of the late 1970s and increased precipitation amounts in the mid-1980s. According to the DWR groundwater data,current conditions since 1995 show relatively stable water levels at depths between 95 and 100 feet for the unconfined aquifer. Based on the historical trends of groundwater level measurements,the observed groundwater levels are influenced by seasonal groundwater fluctuations,drought, and local groundwater pumping. The water levels could rise from the currently observed average levels due to years of high precipitation,due to reduced regional groundwater pumping,or due to regional aquifer recharge. However,based on the recorded groundwater fluctuations over the t40-year historic trend that represents extreme drought(1977)and years of excessive precipitation,the increase in groundwater levels could reach but may not significantly exceed the maximum historic recorded water level depth of 85 feet. Groundwater levels in the lower confined aquifer were reviewed based on one groundwater well ` located at the project site(4S/6E-04N01-Costa property well)and the nearby well referred to as the Barnes property well (4S/6E-04H01). The hydrographs for these wells are presented in Figures 4.8-5 and 4.8-6.The groundwater depths in the Costa well have fluctuated between RMC Pacific Vernalis Quarry Mining and Reclamation Project 4.8-9 ESA/203015 Draft Environmental Impact Report May 2006