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KLEINFELDER l 1 As seen in the other three wells monitored since 1999 and 2002 (DW-1, DW-2, and DW-3) the water levels, including the domestic well, have been relatively consistent showing a general drop in the depth to groundwater. It should be noted that even though the pumps were shut down prior to recording the water F� levels,;Don.Pedro Pump, LLC has stated that "Depths could be affected by length of recovery tune." Potential Groundwater Influence Due To Leaka a From The California A ueduct The San Joaquin.County Environmental Health Department (EHD) has expressed concern over- water levels in the vicinity of the Vernalis Quarry and the possible influence caused by leakage of . l the California Aqueduct to adversely impact the Vernalis Quarry wells. Based on the depths to water levels recorded in the four wells monitored near the site, and the depth of the quarry operations the followi observations were me: 4 Depth of groundwater measured in the closest two wells (DW-1 and the domestic well) to the . California Aqueduct have shown increases in the depth measured over the past five monitoring events since 1999. The depth to water in DW-1 has increased approximately 65 feet, and to a lesser degree the depth to� water in the domestic well has increased_appcatel5 feet. Similar f depth to groundwater increases were noted in the other two wells (DW-2 and DW73) with increases of approximately 7 to 13 feet respectively. Currently, the quarry has been excavated to a depth of approximately 40 feet bgs. Shallow groundwater infiltration into the bottom of the quarry pit has been reported as non-existent. Based on test boring data, groundwater is estimated to be_approximately 125 to 130 feet bgs. It does not appear that there is a substantial shallow groundwater flow in the area of the quarry, nor does it appear that an artificial shallow groundwater.condition exists as a result of leakage from Ithe California Aqueduct in the vicinity of the quarry. The position that no influence on local groundwater caused by leakage of the California Aqueduct is supported by the depth to groundwater data supplied by Don Pedro Pump. Depth to groundwater in the wells noted in this report shows groundwater to be relatively deep. It.is estimated that if the aqueduct was influencing the groundwater at the site it would be seen in at least the domestic well located nearesi to the aqueduct, where the de th to groundwater has been, i L shown to have dropped over the RaLt three years. Additionally, the current excavated depth of the quarry has shown no seepage from shallow regions. Similar results were obtained from the monitoring wells installed between the Delta Mendota Canal and the sites eastern boundary. These wells have remained,dry with no apparent leakage or seepage facilitated by the nearby canal. } CONCLUSIONS AND RECOMMENDATIONS The groundwater monitoring of the three wells (DW-1, DW-2, and DW-3) is now complete until 7 December 2003. The concentrations of the noted analytes have remained consistent compared to 29131.801 /ST03R7$1 Page 3 of 5 Copyright 2003 Kleinfelder,Inc. . June 2,2003. {