Laserfiche WebLink
i <br /> 2 0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS <br /> ' On November 13 and 14, 1997, Ramage Environmental monitored and sampled groundwater <br /> from the two deep vapor extraction wells (VW-1 and VW-2) and the five original groundwater <br /> ' monitoring wells at the site <br /> r2.1 Groundwater Monitoring <br /> Depth-to-groundwater measurements were taken in all five original groundwater monitoring <br /> wells, VW-1 and VW-2 to evaluate groundwater flow and gradient characteristics The depth-to- <br /> groundwater beneath the site ranged from 47 81 feet below ground surface (bgs) in MW-1 to <br /> ' 49 18 feet bgs in MW-5 The groundwater elevation beneath the site ranged from 30 81 feet <br /> below mean sea level (MSL) in MW-1 to 31 09 feet below MSL in MW-5 Groundwater levels <br /> ' have dropped an average of 1 94 feet since groundwater levels were last measured on August <br /> 13, 1997 Since May 1992, the groundwater elevation in MWA has risen 18 42 feet The <br /> historical groundwater monitoring data are summarized in Table 1 <br /> Groundwater flow directions and gradients are illustrated on the groundwater surface map <br /> (Figure 3) The groundwater gradient was calculated at 0 003 foot/foot in a northerly direction <br /> Because groundwater levels in the five groundwater wells are above the screened interval, the <br /> calculated flow and gradient characteristics may be unreliable The groundwater flow and <br /> gradient calculations do not utilize groundwater levels in the sod vapor extraction wells because <br /> their wellhead elevations have not been surveyed <br /> 1 <br /> 22 Groundwater Sampling and Analysis <br /> Groundwater from the deep sod vapor extraction wells (VW-1 and VW-2) was sampled to <br /> ' evaluate the concentration of gasoline hydrocarbons at the groundwater table Groundwater <br /> from monitoring wells (MW-1, MW-2, MW-3, MW-4 and MW-5) was also sampled for the first <br /> ' time since April 26, 1996 <br /> The seven wells were purged of at least three well volumes using a decontaminated bailer The <br /> ' well monitoring, purging and sampling data are documented on the Groundwater Monitoring and <br /> Sampling Forms (Appendix A) <br /> 2 <br /> r <br /> r <br />