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1 <br /> i2 0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS <br /> On May 6, 2002, to comply with quarterly groundwater monitoring requirements, Ramage <br /> Environmental monitored and sampled the seven monitoring wells <br /> 2.1 Groundwater Monitoring <br />' Upon arrival at the site, each of the wellheads was inspected, unlocked and opened Depth-to- <br /> groundwater was measured in each of the wells using a water level indicator capable of <br /> 1 measuring groundwater to within 0 01 foot <br /> The static depth-to-groundwater ranged from 39 69 feet bgs in MW-7 to 4121 feet bgs in MW-1 <br /> The corresponding groundwater surface elevation ranged from a high of 21 60 feet below mean <br /> sea level (msl) at MW-6 to a low of 22 31 feet below msl at MW-2 The resulting groundwater <br /> surface appears as an irregular plane dipping to the east-southeast at a gradient of approximately <br /> 0 0031 foot/foot As shown on the groundwater surface contour map (Figure 4), a groundwater <br /> depression observed at MW-2 is not consistent with the regional groundwater surface The <br /> groundwater monitoring data are summarized in Table 1 <br /> 22 Groundwater Sampling and Analysis <br /> Following the groundwater level measurements, each of the wells was purged and sampled The <br /> wells were purged using a pump and disposable tubing until at least three well casing volumes <br /> were removed and/or after groundwater temperature, pH and electrical conductivity had stabilized <br /> Fallowing well purging, groundwater was sampled from the wells using dedicated disposable <br /> bailers and laboratory-supplied containers, which were transported in an iced cooler with chain-of- <br /> custody documentation to Kiff Analytical, LLC (Kiff), a state of California certified hazardous waste <br /> testing laboratory (Certification #2236) Kiff analyzed the groundwater samples for TPH-as- <br /> gasoline, BTEX, MTBE, di-isopropyl ether(DIPE), ethyl tertiary butyl ether (ETBE), tertiary amyl <br /> methyl ether (TAME), tertiary butanol (TBA), and 1,2-DCA by EPA Method 8260B <br />' Gasoline compounds were only detected in two of the groundwater table monitoring wells (MW-2 <br /> and MW-3) The highest concentrations of gasoline hydrocarbons (180,000 Rg/l of TPH-as- <br /> gasoline, 4,100 µg/l of benzene, 34,000 µg/l of toluene, 5,000 µg/l of ethylbenzene, 27,000 µg/1 of <br /> xylenes, and 260 µg/I of 1,2-DCA) were detected in the groundwater sample collected from MW-2 <br /> 7 <br />