ARCHIVED REPORTS_XR0002425 - Laserfiche WebLink

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i - The wells and piezorneters were constructed using Schedule 40 PVC, with 0 020 inch slot screen Joined by flush threads Screen length was ten feet on both the well and the piezometers and he bottom of each casing was capped with a threaded silt catching cap Sufficient blank PVC casing was used above the screen to reach the ground surface At least six inches of sand (size /20) was placed below the screen The sand pack around the screen was tremmied in place by pouring small quantities of sand into the annulus between the auger and the screen The augers were removed slowly to allow the sand to fall out u£ the auger into the annulus Sand was maintained within the auger at all tunes to minimize sloughing around the screen Sand was placed to a height of approximately one foot above the top of the casing Bentonite pellets were placed on the sand and were hydrated After hydration the bentonite seal thicknesses were approximately two and one-half feet The borings were then grouted to the surface using a grout :nix containing five percent bentonite Wells were secured using locking caps The well heads were set within a flush mounted utility box that was founded in the giout seal and stabilized with a grout strengthened with sand. The flush box was set approximately one inch above grade to ensure drainage away from the box The well completion details for the piezometers and well are included as Appendix C The well completion details show the specifics of the placement of the well and the piezometers A relative survey was completed by a qualified engineers to an accuracy of 0 01 feet of the elevations of the top of the casing for use in determining groundwater gradient. The well and piezometers were marked on the north side of the casing to ensure consistent water level depth measurements. In addition, the well and piezometers were labeled inside the utility box using the naming scheme presented in this report Table 3 contains the survey data along with groundwater elevation data pertinent to the calculatio;i of the groundwater gradient Boring logs showing pertinent information concerning the placement of bonngs are included in Appendix D During the placement, soil samples were taken for the purpose of soil logging and vadose zone chemical analysis to define the limits of soil contamination In addition soil cuttings and drilling pressure were monitored to detect any change in lithology and to detect the presence of hydrocarbon contamination as the drilling proceeded 1.3 Groundwater Sampling and Analysis Procedure A single round of groundwater sampling was conducted immediately after the monitoring well was developed, resulting in the collection of one groundwater 5 i BRUNSING ASSOCIATES, INC ��®�