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• i <br /> Once these readings stabilized after two consecutive purge volumes (aquifer water is <br /> . assumed to be entering the well), and the well recovered to about 80% of the initial <br /> water level, the sample was collected from the well Purge water was stored on-site In <br /> drums A new disposable bailer was used to obtain the groundwater sample which <br /> was placed with minimum cavitation Into the appropriate, laboratory prepared sample <br /> containers leaving no headspace The sample container was then Immediately <br /> capped and placed In a chilled Ice chest for shipment to Priority Environmental <br /> Laboratory in Milpitas, California (a State Certified Testing Lab) under chain-of- <br /> custody documentation <br /> Groundwater Contour Map and Flow Gradient <br /> A groundwater contour map was prepared for the data listed in Table 1 above (see <br /> Figure 1) Groundwater elevation contours were plotted to a known datum from the <br /> measurements The groundwater flow direction was to be the northerly under a <br /> calculated gradient of 0 005 The flow direction is consistent with historic observed <br /> trends, and remains relatively flat <br /> Chemical Analytical Methods and Results <br /> Three groundwater samples were analyzed using EPA Methods 5030/8015 and 602 <br /> for Total Petroleum Hydrocarbons as Gasoline (TPHG), Benzene, Toluene, <br /> Ethylbenzene and Xylene (BTEX) The chain-of-custody and the Laboratory Analysis <br /> Results are attached The analytical results of the groundwater samples revealed the <br /> following (see Table 2) <br /> Table 2 Groundwater Data <br /> Well Date TPHG Benzene Toluene Ethylbenzene Xylene <br /> No Sampled -------------------------- ug/l <br /> MW-1 3128196 ND ND ND ND ND <br /> MW-2 3128196 12,000 80 5 0 7 7 20 <br /> MW-3 3128196 2,500 21 12 12 24 <br /> Blank 3128196 ND ND ND ND ND <br /> ND - None detected ugA -Micrograms per liter <br /> DISCUSSION <br /> Concentrations of TPHG were observed In the Wells MW-2 and MW-3 with very low <br /> BTEX components Contaminants were not observed in MW-I The BTEX <br /> concentrations represent degraded levels A relatively moderate to slow groundwater <br /> movement is inferred from the groundwater measurement data Overall site <br /> groundwater movement is consistent with a historic northerly direction although a "flow <br /> reversal" was observed in the previous quarter In our opinion, this was due to a very <br /> flat gradient at that time of about one-one hundredth of one foot elevation difference <br />