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2.0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS On August 13, 1997, Ramage Environmental monitored and sampled groundwater at the site ' 2.1 Groundwater Monitoring ' Depth-to-groundwater measurements were taken in all five groundwater monitoring wells and the two deep soil vapor extraction wells (VW-1 and VW-2) to evaluate groundwater flow and gradient characteristics The depth-to-groundwater beneath the site ranged from 46 03 feet below ground surface (bgs) in MW-1 to 47 39 feet bgs in MW-5 The groundwater elevation beneath the site ranged from 28 92 feet below mean sea level (MSL) in MW-2 and MW-3 to 29 30 feet below MSL in MW-5 Groundwater levels have dropped an average of 2 95 feet since groundwater levels were last measured on May 15, 1997 Since May 1992, the groundwater elevation in MW-1 has risen 20 20 feet The historical groundwater monitoring data are summarized in Table 1 Groundwater flow directions and gradients are illustrated on the groundwater surface map (Figure 3) In general, the maximum groundwater gradient was calculated at 0 01 foottfoot in a northerly direction between MW-4 and MW-5 Because groundwater levels in the five groundwater wells are above the screened interval, the calculated flow and gradient characteristics may be unreliable The groundwater flow and gradient calculations do not utilize ' groundwater levels in the soil vapor extraction wells because their wellhead elevations have not been surveyed 1 22 Groundwater Sampling and Analysis Groundwater from the deep sod vapor extraction wells (VW-1 and VW-2) was sampled to evaluate the concentration of gasoline hydrocarbons at the groundwater table The groundwater monitoring wells (MW-1, MW-2, MW-3, MW-4 and MW-5)were not sampled because of groundwater levels significantly above the screened interval of these wells The deep soil vapor extraction wells (VW-1 and VW-2)were purged of at least three well ' volumes using a decontaminated Teflon® bailer The well monitoring, purging and sampling data are documented on the Groundwater Monitoring and Sampling Forms (Appendix A) 71 2