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2 0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS <br /> rOn November 1, 2001, Ramage Environmental monitored and sampled groundwater at the site <br /> ' 21 Groundwater Monitoring <br /> Depth-to-groundwater measurements were taken in all nine of the groundwater monitoring wells <br /> ' to evaluate groundwater flow and gradient characteristics Groundwater surface elevations were <br /> not calculated for MW-1 and the two deep soil vapor extraction wells (VW-1 and VW-2), <br /> ' because their wellhead elevations were moved during the installation of the former soil vapor <br /> extraction and air sparging system These wellheads will be re-surveyed dunng the next phase <br /> of site investigation work <br /> r <br /> In the nine wells monitored, the depth-to-groundwater beneath the site ranged from 42 77 feet <br /> below ground surface (bgs) in MW-1 to 46 72 feet bgs in MW-7 MW-7 is completed above- <br /> grade and protected with a monument casing The groundwater elevation beneath the site <br /> ranged from a high of 28 17 feet below mean sea level (MSI`) in MW-3 to a low of 28 57 feet <br /> ' below MSL in MW-5 The cumulative groundwater monitoring data are summarized in Table 1 <br /> '• The groundwater flow direction and gradient are illustrated on the groundwater surface map <br /> (Figure 3) The groundwater gradient is approximately 0 0055 foot/foot in a northeasterly <br /> direction This is consistent with the historical groundwater gradient and flow direction <br /> 22 Groundwater Sampling and Analysis <br /> ' Groundwater was sampled from seven monitoring wells (MW-1 through MW-7), Irrigation Well <br /> #2, and two deep soil vapor extraction wells (VW-1 and VW-2) Each of the monitoring wells <br /> ' and deep soil vapor extraction wells was purged of at least three well volumes using a pump and <br /> disposable tubing Following purging and recharge, groundwater samples were collected from <br /> ' the wells using dedicated and disposable sampling bailers Irrigation Well #2 was allowed to <br /> flow at the wellhead until the downhole pump was automatically activated A groundwater <br /> sample was collected directly at the wellhead through a sample port <br /> The groundwater samples were contained in laboratory-supplied containers, labeled, and <br /> ' packed in an iced cooler for transport with chain-of-custody documentation to Kiff Analytical, LLC <br /> (Kiff) a state of California certified analytical laboratory (#2236) <br /> 5 <br />