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1 <br /> • 3 0 GROUNDWATER MONITORING, SAMPLING AND ANALYSIS <br /> On March 20, 2000, Ramage Environmental monitored and sampled groundwater from the three <br />' on-site monitoring wells, and sampled the on-site domestic water supply well <br /> 31 Groundwater Monitoring <br /> t <br /> Upon arrival at the site, each of the wellheads was inspected, unlocked and opened Depth-to- <br /> groundwater was measured in each of the wells using a water level indicator capable of <br /> measuring groundwater to within 0 01 foot <br />' The static depth to the groundwater table, as measured in the three groundwater monitoring wells, <br /> ranged from 73 29 feet bgs in MW-1 to 74 05 feet bgs in MW-3 The corresponding groundwater <br />' surface elevation ranged from a high of 26 85 feet (arbitrary datum) at MW-2 to a low of 26 53 feet <br /> (arbitrary datum) at MW-1 The resulting groundwater surface appears as a regular plane dipping <br /> to the north-northeast at a gradient of approximately 0 005 foot/foot Since the groundwater <br /> surface was last measured in December 2000, groundwater levels rose an average of 2 45 feet, <br /> the gradient decreased, and the groundwater flow direction shifted back slightly to the north A <br /> groundwater surface contour map is included as Figure 3 The well construction details, wellhead <br /> elevations and groundwater monitoring data are summarized in Table 1 <br />' 32 Groundwater Sampling and Analysis <br /> Following the groundwater level measurements, each of the wells was purged and sampled The <br /> wells were purged using a pump and dedicated disposable tubing, until at least three well casing <br /> volumes were extracted and/or after groundwater temperature, pH and electrical conductivity <br />' values had stabilized Following well purging and recharge, groundwater was sampled from the <br /> wells using dedicated disposable bailers and laboratory-supplied containers Each sample <br />' container was labeled, packaged in an iced cooler and transported with chain-of-custody <br /> documentation to KEff Analytical, LLC (Kill), a state of California certified hazardous waste testing <br /> laboratory (Certification #2236) Kiff analyzed each of the groundwater samples for TPH-as- <br />' gasoline, BTEX, MTBE, DIPS, ETBE, TAME, and TBA by EPA Method 8260B <br /> I <br /> 9 <br />