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6 January 1993 <br /> (GeoAudit CV42F5-1. 26) <br /> Page 2 of 3 <br />' <br /> hydrocarbons (TPH as gasoline and TPH as diesel) and purgeable <br /> aromatics (BTE&X) in accordance with the appropriate EPA methods. <br />' FINDINGS <br /> Casing elevations were surveyed relative to a temporary bench mark <br /> with an assumed elevation of 100 feet, and the depth to groundwater <br /> was measured with a Solinist water level meter. The relative water <br /> elevation for the monitoring wells was then calculated by <br />' subtracting the depth from the casing elevation (Table 1) . <br />' TABLE 1--GROUNDWATER DATA* <br /> Relative Depth Relative Ground Water <br /> Casing to Water Elevation <br /> Well No. Elevation 6192 30 92 12 92 6192 IV 92 12J-9-2 <br /> 0. 31 10.95 11. 25 10. 41 89 . 36 89 . 06 89 .90 <br /> MW-1 10 <br /> MW-2 00. 31 10.95 9 . 58 9 . 30 88 . 82 90. 19 90. 47 <br /> 26 9 . 10 89 . 41 90. $7 91. 03 <br /> MW-3 100 . 13 10.72 9 . <br /> ' * All mesurments in feet <br /> These results indicate that water levels are slightly higher in all <br /> wells than they were during the previous sampling events. This may <br /> ' be due to tidal effects, since the December samples were taken at <br /> or dust before high tide, whereas previous samples were taken near <br /> low tide or during rising tide. Tide tables for the December sample <br /> dates are included in Appendix B. <br /> As in the September sampling event, the water level is highest in <br /> MW-3 and lowest in MW-1, confirming that flow is generally to the <br /> south, away from the ship channel. The hydraulic gradient <br /> determined from the data is 0. 0096 ft/ft to S 330 E (Figure 2) . The <br /> direction isveryflatterathan the gradient ofto that measured n0 . 01126 ft/ft measured <br /> but is slightly <br /> at that time. <br /> ' No petroleum hydrocarbons were detected in any of the samples <br /> (Appendix C) . <br /> ' RECOMMENDATIONS <br /> TPH and BTE&X concentrations have generally decreased since the <br /> first samples were obtained in June 1992 , and no contamination was <br /> detected in the most recent sampling. Geological Audit recommends <br /> that this trend be verified by remeasuring and sampling the wells <br /> in March 1993 . <br /> 1 <br />