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2.0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS On January 29, 2009, to monitor the plume of impacted groundwater and to comply with quarterly groundwater monitoring requirements, Ramage Environmental monitored and sampled the eight wells. The sample information field sheets are included in Appendix A. .1 Groundwater Monitoring To calculate the groundwater gradient and flow direction, Ramage Environmental measured the depth-to-groundwater in the wells to within o.01-foot using a water level indicator. The depth to NAW the groundwater tele in the eight wells ranged from 33.50 feet bgs its MW-6 to 42.00 feet bgs in MW-4, The corresponding groundwater surface elevations in the eight monitoring wells ranged from a high of 17,49 feet below mean sea level (rust) in well W-7 to a low of 18.032 feet below nsl at MW-4. The resulting groundwater surface appears as an irregular plane generally dipping toward the northeast at a gradient of approximately O 0013 foot/foot, A groundwater surface contour map is included as Figure 3 and the well construction details, wellhead elevations and groundwater monitoring data are summarized in Table 5. Between October 29, 2008 and January 29, 2009, the groundwater potentiometric surface in the eight monitoring wells rose an average of 1,32 feet, the groundwater gradient increased from g. it jl2 to 0.0€313 foottfoot, and the groundwater flow direction remained toward the northeast. These groundwater flow and gradient characteristics appear to be consistent with historical and seasonal trends. 2.2 - Groundwater Sampling and Analysis Following groundwater level measurements, Ramage Environmental purged and sampled the eight wells. The wells were purged with a pump and dedicated disposable tubing until at least tares well casing volumes had been removed and/or after groundwater temperature, ply and electrical conductivity values had stabilized. Groundwater was sampled from the wells using disposable polyethylene trailers and laboratory-supp lied containers, Each sample container was transported in an iced cooler with chain-of-custody documentation to Excelchern Environrne� tal Lab (Exlchern , a state tat California certified'hazardous waste testing laboratory #2119). E celche n analyzed each sample for TPH-as-jet fuel and T l -as-diesel by EFTA Method 801 5M, for TPM-as-gasoline,benzene,toluene, eth l en ene, xylenes ( °TE by EPA Method 8021 B1801 5M, and for methyl tertiary butyl ether (MTBE), di-isopropyl ether(RIPE), ethyl tertiary butyl ether ETRE ,tertiary amyl methyl ether(TAME), tertiary butanol (TBA), 1,2-dichloroethane (1,2-DCA), and 1,2- ihromo thane(EDB) by EFTA Method 52601, 7