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ING SAMPLING AND ANALYSIS • 2 0 GROUNDWATER MONITORING, On February1$ 1999, Ramage Environmental monitored and sampled groundwater at the site 9 21 Groundwater Monitoring Depth-to-groundwater measurements were taken all three of the groundwater monitoring wells to evaluate groundwater flow and gradient characteristics The depth-to-groundwater beneath the site ranged from 6 78 feet bgs in MW-3 to 7 17 feet bgs in MW-1 The groundwater elevation beneath the site ranged from a high of 42 21 feet mean sea level (MSL) in MWA to a low of 41 94 feet MSL in MW-2 Groundwater levels have risen an average of 0 95 feet since groundwater levels were last measured on November 5, 1998 Current and historical groundwater monitoring data are summarized in Table 1 The groundwater flow direction and gradient are illustrated on the groundwater surface map (Figure 3) The groundwater gradient was calculated at 0 005 foot/foot in a northeasterly direction This result is consistent with historical groundwater flow and gradient data 22 Groundwater Sampling and Analysis Following the groundwater level measurements, each of the wells was purged and sampled to evaluate the presence of dissolved petroleum hydrocarbons at the groundwater table The wells were purged using a battery-operated downhole pump until at least three well casing volumes were extracted Following well purging, groundwater was sampled from the wells using dedicated disposable bailers and laboratory-supplied containers Each sample was labeled, packaged in an iced cooler and transported under chain-of-custody documentation to Kiff Analytical, LLC (Kiff), a state of California certified hazardous waste testing laboratory (Certification #2236) The laboratory analyzed the groundwater samples for TPH-as-diesel, TPH-as-gasoline, BTEX and MTBE by modified EPA Method 8015/8020 The laboratory reports and chain-of-custody documents are included in Appendix A 5