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' 2.0 GROUNDWATER MONITORING SAMPLING AND ANALYSIS IOn July 29, 2002, to comply with quarterly groundwater monitoring requirements, Ramage Environmental monitored and sampled the monitoring well network 2.1 Groundwater Monitoring Upon arrival at the site, each of the wellheads was inspected, unlocked and opened Depth-to- groundwater was measured in each of the wells using a water level indicator capable of ' measuring groundwater to within 0 01 foot The static depth-to-groundwater ranged from 40 87 feet bgs in MW-7 to 42 38 feet bgs in MW-1 The corresponding groundwater surface elevations ranged from a high of 22 85 feet below mean sea level (msl) at MW-6 to a low of 23 53 feet below msl at MW-2 The resulting groundwater surface appears as an irregular plane dipping to the east-southeast at a gradient of approximately 0 0023 foot/foot As shown on the groundwater surface contour map (Figure 4), a groundwater depression observed at MW-2 is not consistent with the regional groundwater surface The groundwater monitoring data are summarized in Table 1 2.2 Groundwater Sampling and Analysis In MW-2, a layer of separate-phase hydrocarbons (free product) approximately 0 02 feet thick was observed Approximately 0 25 ounces of product were removed from MW-2, and the well was not ' sampled Each of the other wells was purged and sampled The wells were purged using a pump and disposable tubing until at least three well casing volumes were removed and/or after groundwater temperature, pH and electrical conductivity had stabilized Following well purging, groundwater was sampled from the wells using dedicated disposable bailers and laboratory-supplied containers, which were transported in an iced cooler with chain-of- custody documentation to Kiff Analytical, LLC (Kiff), a state of California certified hazardous waste testing laboratory (Certification #2236) Kiff analyzed the groundwater samples for TPH-as- gasoline, BTEX, MTBE, di-isopropyl ether(DIPS), ethyl tertiary butyl ether (ETBE), tertiary amyl ' methyl ether(TAME), tertiary butanol (TBA), and 1,2-DCA by EPA Method 8260B I 7 1