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' 2 0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS • ' On November 9, 2000, Ramage Environmental monitored and sampled groundwater at the site 21 Groundwater Monitoring Depth-to-groundwater measurements were taken in six groundwater monitoring wells (MW-2, ' MW-3, MW-4, MW-5, MW-6 and MW-7)to evaluate groundwater flow and gradient characteristics Depth-to-groundwater measurements were not taken from MW-1 and the two deep soil vapor extraction wells (VW-1 and VW-2), because their wellhead elevations were moved during the installation of the soil vapor extraction and air sparging system ' In the six wells monitored, the depth-to-groundwater beneath the site ranged from 38 23 feet below ground surface (bgs) in MW-4 to 41 91 feet bgs in MW-7 MW-7 is completed above- grade and protected with a monument casing The groundwater elevation beneath the site ranged from a high of 23 48 feet below mean sea level (MSL) in MW-2 to a low of 23 79 feet below MSL in MW-7 Groundwater levels dropped an average of 1 08 feet, since groundwater levels were last measured on August 24, 2000 Since May 1992, the groundwater levels have risen approximately 28 2 feet The current and historical groundwater monitoring data are ' summarized in Table 1 The groundwater flow direction and gradient are illustrated on the groundwater surface map (Figure 3) The groundwater gradient was calculated at 0 0041 foottfoot in a northeasterly direction This is consistent with the historical groundwater gradient and flow direction 2.2 Groundwater Sampling and Analysis Groundwater from all seven monitoring wells (MW-1 through MW-7), Irrigation Well#2, and the two deep soil vapor extraction wells (VW-1 and VW-2) was sampled Each of the monitoring ' wells was purged of at least three well volumes using a pump and disposable tubing Following purging and recharge, groundwater samples were collected from the wells using dedicated and disposable sampling bailers Irrigation Well#2 was allowed to flow at the wellhead until the ' downhole pump was automatically activated A groundwater sample was collected directly at the wellhead through a sample port The groundwater samples were contained in laboratory- supplied containers, labeled, and packed in an iced cooler for transport with chain-of-custody documentation to Kiff Analytical, LLC (Kiff) a state of California certified analytical laboratory (#2236) ' S