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2 3 1 Monitoring Well Construction, Development and Elevation Surve <br /> V&W Drilling installed the four wells in 8-inch diameter soil borings drilled by a truck-mounted drill <br /> rig, equipped with hollow stem augers The total depths of the wells ranged from 23 to 32 feet <br /> MW-1, MW-3 and MW-4 consisted of 15 feet of two-inch diameter, Schedule - <br /> 40, flush threaded <br /> i <br /> and machine-slotted (0 020-inch) polyvinyl chloride (PVC) well screen MW-2 was constructed <br /> with only 10 feet of screen Blank PVC casings were threaded into the tops of the well screens <br /> and extended to the surface <br /> In each well, a filter pack of#3 graded and washed silica sand was laced through P g p the hollow <br /> stem augers as they were slowly retrieved and until the sand pack reached approximately two feet <br /> above the top of the screened interval Following the placement of the sand packs, the driller <br /> developed each of the wells by the surge and purge method Each of the wells was surged for <br /> ' approximately 5 to 10 minutes using a wire-line surge block system Between surging cycles, <br /> approximately 2 to 6 gallons of groundwater were bailed from each well Fallowing well <br /> development, two feet of hydrated bentonite chips were placed within the annular space between <br /> the borehole and the well casing A surface seal of neat cement grout was placed over the <br /> hydrated bentonite, under PHSIEHD observation The tops of the wells were secured with water- <br /> tight locking caps and 8-inch diameter, traffic-rated utility boxes <br /> During October 2000, Morrow Surveying (California Licensed Land Surveyor#5161) surveyed <br /> each of the newly-installed wellheads Morrow Surveying located each of the wells and measured <br /> the elevation of the top of each well casing to the nearest 0 01 foot, referenced to USC&GS <br /> Bench Mark C-958 (Elevation 49 48 feet) The surveyor's report is included as Appendix C <br /> Based on the distribution of the existing soil sample data, no soil samples were collected for <br /> laboratory analysis, during drilling of the monitoring wells In the field, a geologist logged the drill <br /> cuttings for geologic and hydrogeologic characteristics according to the Unified Soil Classification <br /> System Monitoring well logs are included as Appendix D <br /> 2 3 2 Groundwater Monitoring_Sampling and Analysis <br /> On September 25, 2000, groundwater from the four newly-installed wells was monitored and <br /> sampled Upon arrival at the site, each of the wellheads was inspected, unlocked and opened <br /> Depth-to-groundwater was measured in each of the wells using a water level indicator capable of <br /> measuring groundwater to within 0 01 foot <br /> 10 <br /> 1 <br />