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7hN3dwell8RO110 All groundwater samples contained TPHg, ranging from 21,000 micrograms per liter (µg/1) in Boring 16B-11 to 240,000 µg/1 in boring 16B-8 BTEX compounds were detected in all samples, with benzene ranging from 700 �ig/l in boring 16B-11 to 10,000 µg11 in boring 16B-8 Table 2 summarizes the analytical results for groundwater 1 5 0 WELL DESTRUCTION During December 2003 Treadwell & Rollo submitted a well destruction workplan to the SJCEHD (Treadwell & Rollo 2003b), which was accepted on 12 January 2003 (SJCEHD 2003b) Between 1 March 2004 and 26 March 2004, all on-site wells were destroyed according to the procedures described in the workplan, except for sparging well SW-10 which could not be located Most of the wells were destroyed because they were un-used wells from previously abandoned air sparging, or water or soil vapor extraction systems Five of the monitoring wells had been installed prior to the regional rise in groundwater had top of screen intervals up to 5 feet below the water table, and therefore were not constructed properly given current conditions The remaining four monitoring wells and the ozone infections wells were destroyed because of the grading requirements and building locations of the proposed site redevelopment Table 1 identifies the destruction method used for each well The following is a summary of the wells destroyed • Twenty-two air sparging wells (SW-1 through SW-9 and SW-11 through SW-23) associated with a soil vapor extraction system that was abandoned in February 2001 G Five vapor extraction wells (VW1 through VW5) installed in the 1990s which were screened below the current groundwater table and not in use • Two groundwater extraction wells (EW3 and EW4) installed in the 1990s, which were never used • All 17 ozone sparging wells at the site 7 25971014 DGD 7 April 2004