ARCHIVED REPORTS XR0000203 - Laserfiche WebLink

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23 Vapor Extraction Well Construction Vapor extraction well VW-1 was constructed using four-inch diameter PVC casing to a depth of approximately 98 feet bgs The lower 85 feet of well VW-1 was constructed using 0 03-inch slotted screen FVC casing A filter pack consisting of Monterey #3 sand was placed around the screen from ' the bottom of the borehole to an elevation of approximately two feet above the screened zone An approximately two-foot thick seal consisting of hydrated bentonite chips was placed above the filter pack A mixture of bentonite powder and cement was placed from above the seal to the existing grade level A traffic-rated security wellhead cover was used to complete the well construction L4 Vapor Extraction Monitoring Well Construction Vapor extraction monitoring wells VM-1 and VM-2 were constructed using two-inch diameter PVC casing to a depth of approximately 60 feet The lower 45 feet of the wells were constructed using 0 020-inch slotted screen PVC casing A filter pack consisting of Monterey #3 coarse sand was placed around the screens from the bottom of the screened interval to an elevation of approximately two feet above the screen An approximately two-foot thick seal consisting of hydrated bentonite chips was placed above the filter pack at each well A mixture of bentonite powder and cement was ' placed from above the seal to the existing grade level at each well Traffic-rated security wellhead covers were used to complete the well constructions 25 Groundwater Monitoring Well Construction Groundwater monitoring wells MW-11, MW-25 and MW-26 were constructed using four-inch ' diameter PVC casing installed to a depth of approximately 75 feet bgs The lower 20 feet of the wells were constructed using 0 020-inch slotted screen PVC casing A filter pack consisting of ' Monterey #3 coarse sand was placed around the screens from the bottom of the screened interval to an elevation of approximately two feet above the screen An approximately two-foot thick seal consisting of hydrated bentonite chips was placed above the filter pack at each well A mixture of bentonite powder and cement was placed from above the seal to the existing grade level at each well Traffic-rated security wellhead covers were used to complete the well constructions 26 Well Development ' The vapor extraction and groundwater monitoring wells were developed using a surge block and intermittent groundwater extraction to densify the sand pack and remove sediment The groundwater extraction was accomplished using a Grundfos electric submersible pump Extracted groundwater ' was pumped into DOT 17-H 55-gallon drums which were labeled and stored on-site pending disposal following regulatory protocol ' 27 Analytical Methods Soil samples were transported to the laboratory for analytical testing Selected soil samples were analyzed for the presence of TPHg following EPA Test Method 8015, and BTEX and methyl tert- Project No 58100-06-18A -6- December 9, 1996