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2 . 0 GROUNDWATER FLOW DIRECTION AND GRADIENT <br /> On March 29, 2004, ASE measured the depth to water in each site <br /> groundwater monitoring well using an electric water level sounder The <br /> surface of the groundwater was also checked for the presence of <br /> free-floating hydrocarbons or sheen using an oil/water interface probe a n d <br /> a product thickness bailer No free-floating hydrocarbons were observed in <br /> any of the groundwater monitoring wells this quarter Groundwater <br /> elevation data is presented as Table One <br /> Groundwater elevation (potentiometric surface) contours are plotted on <br /> Figures 2, 3 and 4 Groundwater in the shallow zone (less than 20-feet bgs) <br /> has historically shown a northern or northwestern flow This quarter, the <br /> groundwater flow direction is primarily to the north with a gradient of <br /> approximately 0 001-feet/foot The shallow zone potentiometric surface <br /> map is presented as Figure 2 <br /> Groundwater in the middle zone (55-70-feet bgs) flows toward the south <br /> this quarter at a gradient of approximately 0 004-feet/foot <br /> The groundwater flow in the deep zone (greater than 100-feet) flows <br /> . toward the southeast this quarter at a gradient of approximately 0 001 - <br /> feet/foot <br /> Potentiometric surface differences in wells adjacent to each other b u t <br /> screened in different zones such as monitoring wells MW-6, MW 7 a n d <br /> MW-8 show a decreasing hydraulic head with depth, suggesting t h e <br /> potential for downward groundwater flow <br /> 3 . 0 GROUNDWATER SAMPLE COLLECTION <br /> On March 29, 30 and 31, 2004, ASE collected groundwater samples from <br /> twenty-one of the on-site and off-site groundwater monitoring wells, <br /> recovery wells, and drinking water well for analysis Additionally, Jim <br /> Barton of the RWQCB was onsite March 30 and 31, to collect split-samples <br /> from monitoring wells MW-5, MW-8, MW-9, MW-10, MW-11 and MW- 12 <br /> to undergo independent laboratory analyses <br /> Prior to sampling, the site monitoring wells were purged of three well <br /> casing volumes of groundwater using a Grundfos pump and/or dedicated <br /> polyethylene bailers The pH, temperature, and conductivity of the purge <br /> . water were monitored during evacuation, and samples were not collected <br /> until these parameters stabilized Samples were collected from the wells <br /> Frank's One Stop Quarterly Report -- March 2004 Sampling <br /> -2- <br />