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. 2 GROUNDWATER FLOW DIRECTION AND GRADIENT On December 9, 2004, ASE measured the depth to water in all site groundwater monitoring wells, recovery wells, and piezometers using a n electric water level sounder The surface of the groundwater was also checked for the presence of free-floating hydrocarbons or sheen using a n oil/water interface probe and a product thickness bailer No free-floating hydrocarbons were observed in any of the wells Groundwater elevation data is presented as Table One Groundwater elevation (potentiometric surface) contours are plotted on Figures 2, 3 and 4 Groundwater in the shallow zone (less than 20 feet bgs) has historically shown a northern or northwestern flow This quarter, the groundwater flow direction was observed as primarily to the northwest with a gradient of between approximately 0 004 feet/foot and 0 0008 feet/foot The shallow zone potentiometric surface map is presented as Figure 2 Groundwater in the middle zone (55-70-feet bgs) flowed toward the south- southwest this quarter at a gradient of approximately 0 002 feet/foot • The groundwater flow in the deep zone (greater than 100 feet) flowed toward the south this quarter at a gradient of approximately 0 0008 feet/foot Potentiometric surface differences in wells adjacent to each other b u t screened in different zones such as monitoring wells MW-6, MW 7 a n d MW-8 show a decreasing hydraulic head with depth, suggesting t h e potential for downward groundwater flow 3 .0 GROUNDWATER SAMPLE COLLECTION On December 9, 10 and 13, 2004, ASE attempted to collect groundwater samples from all of the groundwater monitoring wells, recovery wells, a n d the drinking water well in accordance with the RWQCB Revised Monitoring and Reporting Program, dated August 12, 2004 Monitoring wells MW-1 , MW-2, MW-3, MW-4, MW-6, and recovery wells RW-1, RW-4, and RW-5 were found to either be dry, or did not contain enough water to b e sampled Groundwater samples were collected from each of the remaining wells Prior to sampling, the wells were purged of at least three well casing • volumes of groundwater using disposable polyethylene bailers The pH, Frank's One Stop Quarterly Report — December 2004 Sampling -2-