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�ry 2.0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS On June 29, 2006, to comply with Quarterly groundwater monitoring requirements, Ramage Environmental monitored and sampled the three monitoring wells at the site 21 Groundwater Monitoring _ Upon arrival at the site, each of the wellheads was inspected, unlocked and opened Depth-to- groundwater p p groundwater was measured to within 0 01 feet using a water level indicator r The static depth to the groundwater table, as measured in the three groundwater monitoring wells, ranged from 17 85 feet bgs in MW-2 and MW-3 to 17 87 feet bgs in MW-1 The corresponding groundwater surface elevation ranged from a high of 18 80 feet above mean sea level (msl) at MW-2 to a low of 18 79 feet above msl at MW-1 and MW-3 The resulting groundwater surface appears as a regular plane dipping to the west-northwest at a gradient of approximately 0 0002 foot/foot A groundwater surface contour map is included as Figure 3 The well construction details, wellhead elevations and groundwater monitoring data are summarized in Table 1 22 Groundwater Sampling and Analysis Following groundwater level measurements, all three wells were purged and sampled The wells 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 The sampling information field sheets are included in Appendix A Following well purging and recharge, groundwater was sampled from the wells using dedicated disposable bailers and laboratory-supplied containers The groundwater samples were i 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 r #2119) Excelchem analyzed each of the groundwater samples for TPH-as-diesel, TPH-as- gasoline, benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA Method 8021 B/8015M, 1 and for methyl tertiary butyl ether (MTBE), di-isopropyl ether (DIPS), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether(TAME) and tertiary butanol (TBA), 1,2-dichloroethane (1,2- DCA), and 1,2-dibromoethane (EDB) by EPA Method 8260B As requested by EHD on November 1, 2005, Ramage Environmental added EDB to the groundwater sampling and analysis program, beginning in the fourth quarter of 2005 7