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�A <br /> 1P <br /> 4 .2.3 Well Sampling <br />' Groundwater sampling activities were performed on December 16 , <br /> 1999 Groundwater sampling .involved bailing approximately five <br /> to seven well casing volumes of water out of the wells prior to <br /> sampling The wells were bailed near-continuously until all <br /> stagnant water has been removed The parameters listed above <br /> were measured during purging <br />' One groundwater sample was collected manually (hand-bailed) using <br /> a Teflon bailer from each well The samples were transferred <br /> into 40-m1 VOA vials and 1-11ter amber glass 3ars with a Teflon <br />' septa The samples were stored in a chilled cooler containing <br /> crushed ice to maintain the sample at 4°C for delivery to the <br /> laboratory A field blank sample and duplicate were also <br /> collected for quality control purposes Strict chain-of-custody <br />' protocols were followed in all phases of sample handling <br /> Purged water during sampling activities were contained in a <br />' covered and sealed 55-gallon drum located onsite pending results <br /> of the groundwater samples Purged water from wells containing <br /> detectable concentrations of TPHg, TPHd, benzene, and MTBE will <br /> be disposed offsite <br /> 5. 0 GROUNDWATER ELEVATION AND FLOW <br /> The elevation of the groundwater surface (potentiometrzc surface) <br /> was measured for each monitoring well to evaluate the direction <br />' of groundwater flow at the Site Groundwater level measurements <br /> were recorded by using an electronic water--level probe attached <br /> to an engineer ' s measuring tape graduated to 0 01-foot intervals <br />' Measurements were recorded from the top of the groundwater <br /> surface to the top of the well casing The difference between <br /> the top of the well casing elevation and the depth to the top of <br />' the groundwater surface is a measurement of the potentiometri.c <br /> surface of the groundwater table <br /> Measured groundwater levels at the Site ranged from -5 88 feet <br /> (MW-2 ) to -5 96 feet (MW-3 ) above mean sea level Mapping and <br /> analysis of the groundwater elevation data suggest that the local <br /> groundwater gradient flows in a northeasterly direction The top <br />' of well casing elevations , depth-to-groundwater, and the computed <br /> elevation of the groundwater surface is listed in Table 5 <br /> Figure 5 shows the water-level data collected and the interpreted <br /> contour lines <br />' S <br /> 1 <br />