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2.0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS On December 19, 2002, to comply with quarterly groundwater monitoring requirements, Ramage Environmental monitored and sampled groundwater at the site 21 Groundwater Monitoring Depth-to-groundwater was measured in each of the four monitoring wells using a water level ' indicator capable of measuring groundwater to within 0 01 foot The static depth to the groundwater table ranged from 78 71 feet bgs in MW-1 to 79 60 feet bgs in MW-3 The corresponding groundwater surface elevation ranged from a high of 21 34 feet (arbitrary datum) at MW-2 to a low of 21 11 feet (arbitrary datum) at MW-1 The resulting groundwater surface appears as an asymmetric trough plunging to the northwest at a gradient of approximately 0 0017 ' 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 2 22 Groundwater Sampling and Analysis Following the groundwater level measurements, each of the wells was 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 Following well purging and recharge, groundwater was sampled from the wells using dedicated disposable bailers and laboratory-supplied containers Ramage Environmental also collected a groundwater sample from the on-site water supply well for laboratory analysis Prior to sampling, the well was purged until the well pump was activated Each sample container was labeled, packaged in an iced cooler and transported with chain-of- custody documentation to Kiff Analytical, LLC (Kiff), a state of California certified hazardous waste testing laboratory (Certification #2236) Kiff analyzed each of the groundwater samples for TPH- as-gasoline, BTEX, MTBE, DIPS, ETBE, TAME, TBA and 1,2-DCA by EPA Method 8260B The groundwater samples collected from all four of the groundwater monitoring wells and the on- site water supply well did not contain detectable concentrations of any of the gasoline compounds analyzed These groundwater sample results are summarized in Table 3, and the laboratory ' reports are included as Appendix B 10 1