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Since groundwater is anticipated at approximately 50 feet bgs, the well screen intervals will extend <br /> from approximately 40 to 60 feet bgs Blank PVC casings will thread into the tops of the well <br /> screens and extend to the surface <br /> Filter packs of Monterey#3 graded and washed sand will be placed in the annular spaces <br /> between the boreholes and well casings and approximately two feet above the tops of the <br /> screened intervals (i e , 38 feet bgs) The wells will be surged and purged by the driller, following <br /> the placement of the sand packs and prior to the installation of the well seals Periodic surging <br /> and purging of each well will continue, until at least five well volumes have been removed <br /> Overlying the filter packs, two feet of hydrated bentonite chips will be placed within the annular <br /> Y 9 p Y <br /> spaces between the boreholes and the well casings (i e , 36 to 38 feet bgs) Over the hydrated <br /> bentonite, surface seals of neat cement grout will be installed The tops of the wells will be <br /> secured with watertight caps and traffic-rated, flush-mount street boxes <br /> A licensed land survey surveyor will each of the newly-installed wellheads The surveyor will <br /> Y Y <br /> measure the elevations of the tops of well casings to the nearest 0 01 foot, referenced to a <br /> benchmark The locations of the welts and other site features will also be surveyed <br /> 3 2 2 _Soil Sampling and Analysis <br /> During drilling, undisturbed soil samples will be collected at five-foot intervals using a modified <br /> California split-spoon sampler, lined with two-inch diameter by six-inch long brass or stainless <br /> steel sample sleeves A field geologist will log each of the undisturbed soil samples for <br /> hydrogeologic and lithologic characteristics according to the Unified Soil Classification System, <br /> and screen each sample for any organic vapors using a photoionization detector {PID} <br /> To further evaluate the lateral extent of impacted soil, up to three samples per boring will be <br /> submitted for laboratory analysis Tentatively, the soil samples collected at 20, 45 and 60 feet bgs <br /> will be submitted for analysis Additional soil samples may be submitted for analysis, if necessary <br /> to characterize subsurface conditions Field observations and sample selection will be reviewed <br /> with the EHD inspector, prior to sample submittal to the lab <br /> 9 <br />