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[,eologtral nemAla Page 5 <br /> Dual Phase Extraction Pilot Test Report <br /> Project No 662 2 <br /> February 22,2005 <br /> ' system Each well was pumped until a clear stream of water was produced A total of 50 <br /> gallons was removed from MW-5 and 33 gallons from MW-6 All purge water was <br /> ' contained on site in drums while awaiting disposal <br /> 2.6 Well Survey <br /> The two new monitoring wells and existing wells were surveyed in accordance with <br /> GeoTracker requirements January 12, 2005 The wells' elevation, latitude and longitude <br /> ' data was uploaded in accordance with AB2886 on February 9, 2005 (confirmation #'s <br /> 7573872208 & 2191375553) <br /> 3.4 EXTRACTION WELL <br /> ' Extraction well EW-1 was installed on December 12, 2003 to facilitate an aquifer pumping <br /> test But unfortunately the screened interval of this well (37 — 50 feet bgs) would not allow <br /> ' vapor extraction to address shallow soils at the site GTI proposed installing a second soil <br /> vapor/groundwater extraction well (EW-2) to address the shallower residual soil <br /> contamination beneath the former UST excavation See Figure 2 for this well location <br /> 3.1 Extraction Well Installation <br /> ' Prior to commencmg work, a soil bonng/monitoring well permit was secured and the <br /> SJC/EHD was notified at least 48 hours in advance The subsurface was cleared of <br /> underground utilities by notifying Underground Service Alert <br /> ' On October 26, 2004, V&W Drilling of Isleton, California mobilized to the site to install new <br /> extraction well EW-2 The boring was drilled using a 10 00-inch outside diameter <br /> ' continuous flight hollow stem auger Soil cuttings and drilling decontamination water were <br /> placed in DOT-17 approved 55 gallon drums and retained at the site until their disposal can <br /> be arranged The well was free drilled without sampling due to its proximity to existing <br /> ' wells <br /> The well was constructed using 4-inch diameter PVC casing with flush threads The <br /> ' following table illustrates the construction details <br /> ' Well Diameter Screened Filter Pack Bentonite Cement <br /> Interval (ft) #3 Annular Grout <br /> (ft) Seal (ft) (ft <br /> EW-2 4" 22—32' 20— 32' 18 - 20 0— 18' <br /> A transition seal of bentonite pellets was installed above the sand (#2/12) filter pack, <br /> hydrated and allowed to set for thirty minutes The surface seal was achieved by pumping a <br />