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2.0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS On August 22, 2002, to comply with quarterly groundwater monitoring requirements, Ramage Environmental monitored and sampled the on-site monitoring wells 21 Groundwater Monitoring Upon arrival at the site, each of the wellheads was inspected, unlocked and opened Depth-to- groundwater was measured in each of the wells using a water level indicator capable of measuring groundwater to within 0 01 foot Free product (0 41 feet thick) was observed in MW-1 The depth to static groundwater across the site ranged from 46 35 feet bgs in MW-3 to 47 39 feet bgs in MWA The corresponding groundwater surface elevation ranged from a high of 27 71 feet ' below mean sea level (msl) at MW-3 to a low of 28 18 feet below msl at MW-1 The resulting groundwater surface appears as a regular plane dipping to the west at a gradient of approximately 0 0044 foot/foot A groundwater surface contour map is included as Figure 3 The well construction details and groundwater monitoring data are summarized in Table 1 FBI 2.2 Groundwater Sampling and Analysis Following the groundwater level measurements, MW-2 and MW-3 were purged and sampled Due to the presence of free product, MW-1 was not sampled The wells (MW-2 and MW-3) were purged using a pump and dedicated disposable tubing, until at least three well casing volumes were extracted, and/or after groundwater temperature, pH and electrical conductivity values had stabilized Fallowing well purging and recharge, groundwater was sampled from MW-2 and MW-3 ' using dedicated disposable bailers and laboratory-supplied containers Each sample container was transported in an iced cooler with chain-of-custody documentation to Excelchem Environmental Labs (Excelchem), a state of California certified hazardous waste testing laboratory ' (Certification #2119) Excelchem analyzed each of the groundwater samples for TPH-as-gasoline by EPA Method 8015M, and for BTEX, MTBE, di-isopropyl ether (DIPE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether(TAME), tertiary butanol (TBA), and 1,2-dichloroethane (1,2- DCA) by EPA Method 8260B The groundwater samples collected from MW-2 contained elevated concentrations of TPH-as- gasoline, BTEX, MTBE, TBA and 1,2-DCA The groundwater sample collected from MW-3 did ' not contain detectable concentrations of any gasoline compounds analyzed The groundwater sample results are summarized in Table 2 and the laboratory reports are included as Appendix A 5