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' Second Quarter 2004 Groundwater Report 8200 N Highway 99, Stockton, CA Page 4 of 6 samples were immediately stored in an ice chest refrigerated to a temperature of approximately 4'3C ' and delivered under chain of custody protocol to FGL Laboratories (ELAP #1563) and analyzed for volatile organic constituents utilizing EPA Method 524 2 No VOCs were detected in any of the ' samples collected from the nearby domestic wells Copies of the laboratory reports were submitted to the respective property owner Analytical results of domestic well sampling are summarized in Table 6 A figure showing the location of the domestic wells relative to the site and a copy of the ' laboratory report for each residence is included in Attachment F ' 4.0 ADDITIONAL DRILLING ACTIVITIES On June 30, 2004 and July 1, 2004, pursuant to the work plan and work plan attendum dated ' June 27, 2004 Ground Zero personnel supervised the drilling and installation of monitoring wells MW 15 and MW 16 The wells were completed to a depth of approximately 80 feet below ground surface (bgs) The wells were completed of 2-inch diameter, schedule 40 PVC casing The ' lowermost 20 feet of PVC casing installed in the well is slotted screen (0 01-inch slot size) The filter pack consists of#2/12 pre-washed, silica sand from the bottom of the well to approximately 2 feet above the slotted interval The annular seal consists of hydrated bentonite from the top of the I filter pack to approximately 2 feet above the top of the filter pack, then neat cement grout to the ground surface A protective well monument was cemented into place The well was installed by V&W Drilling, Inc (C57-720904)under the supervision of a Ground Zero geologist Copies of the boring/well logs are included in Attachment G Well locations can be seen on Figures 2 through 5 Soil samples were collected at 5-foot intervals for soil characterization during drilling ' Groundwater was encountered at approximately 70 feet during drilling, but rose to approximately 66 5 feet bgs in the borehole Soil encountered during drilling consisted primarily of clay in silt in the vadose zone (0-65 feet bgs), with silty to well graded sand from approximately 36 to 45 feet ' bgs The saturated zone in the newly installed wells (65-80 feet bgs) consisted primarily of silt, with approximately 10-20% sand, although a poorly graded sand was encountered at 70 feet in well MW16 Soil samples collected at depths of approximately 65 feet bgs (capillary fringe) and 80 feet ' bgs (bottom of the hole) were submitted to Argon Laboratories for analysis of gasoline constituents No gasoline constituents were detected in any of the soil samples Copies of laboratory results are ' included in Attachment H Table 7 summarizes the analytical results of soil samples collected from wells MW15 and MW16 The results from well MW12 have been included for comparison ' The newly installed wells were developed and sampled on July 6, 2004 Fieldwork consisted of measuring the depth to groundwater in all site wells, developing newly installed wells MW15 and MW16, and purging and sampling wells MW12, MW15 and MM16 Well MW12 was re- sampled due to the unexpected non-detect result of MTBE in the last sample collected from the well (June 24, 2004) The technician developed the newly installed wells until the turbidity of the water was visibly reduced, generally to a turbidity measurement of less than 50 NTU The temperature, pH and ' G 1GRGUNDZEITULEBURG\ReportslQMR1200412QM2004 doe