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' 2 0 GROUNDWATER MONITORING,R NG, SAMPLING AND ANALYSIS On April 30, 2001, Ramage Environmental monitored and sampled groundwater p g ater 21 Groundwater Monitoring Depth-to-groundwater measurements were taken in all three monitoring wells to evaluate groundwater flow and gradient characteristics The depth to groundwater beneath the site ranged from 38 03 feet bgs in MW-2 to 39 09 feet bgs in MW-1 The corresponding groundwater surface elevation ranged from a high of 19 74 feet below mean sea level (msl) at MW-3 to a low of 20 21 feet below msl at MW-2 The cumulative groundwater monitoring data are summarized in Table 1 The groundwater flow direction and gradient are shown on the groundwater surface map (Figure 3) In general, the resulting groundwater surface appears as a plane dipping to the south-southeast at a gradient of approximately 0 05 foot/foot This is consistent with groundwater surface measurements taken in previous quarters 22 Groundwater Sampling and Analysis Groundwater from all three wells was sampled to evaluate the concentration of gasoline Lhydrocarbons in groundwater beneath the site Each of the wells was purged of at least three well volumes using dedicated and disposable tubing and a pump Temperature, pH and electrical conductivity measurements were taken during purging Following purging, groundwater samples were collected from all three wells using dedicated and disposable sampling bailers The groundwater samples were collected in laboratory- supplied containers, labeled and packed in an iced cooler for transport with chain-of- custody documentation to Kiff Analytical, LLC (Kiff), a state of California certified analytical laboratory (#2236) Kiff analyzed the groundwater samples for TPH-as-gasoline, BTEX, MTBE, diisopropyl ether (DIPE), ethyl-t-butyl ether (ETBE), tert-amyl methyl ether (TAME), TBA and 1,2- DCA by EPA Method 8260B The laboratory report and chain of custody are included in Appendix A 6