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2 - 0 GROUNDWATER FLOW DIRECTION AND GRADIENT <br /> On July 15, 2003, 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 foi the presence of <br /> free-floating hydrocarbons or sheen using an oillwatei interface probe and <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 northwest with a gradient <br /> of approximately 0 001-feet/foot A 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 /> southwest this quaiter at a gradient of approximately 0 003-feet/foot <br /> The groundwater flow in the deep zone (greater than 100-feet) flows <br /> toward the southeast this quarter at a giadient of approximately 0 006- <br /> feet/foot <br /> Potentiometric surface differences in wells adjacent to each other but <br /> screened in different zones such as monitoring wells MW-6, MW 7 and <br /> MW-8 show a decreasing hydraulic head with depth, suggesting the <br /> potential for downward groundwater flow <br /> 3 . 0 GROUNDWATER SAMPLE COLLECTION <br /> On July 15, 16 and 22, 2003, ASE collected groundwater samples from <br /> fourteen (14) of the on-site and off-site groundwater monitoring wells for <br /> analysis Monitoring wells MW--2 and MW-15 were dry and could not be <br /> sampled <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 /> . using dedicated bailees The groundwater samples were decanted from t h e <br /> bailers into 40-m1 volatile organic analysis (VOA) vials, preserved with <br /> Frank's One Stop Quarterly Report — July 2003 Sampling <br /> -2- <br />