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ARCADIS Ms. Kathy Amaru May 26, 2011 Monitoring Well Installation To minimize the potential for encountering subsurface utilities, the well locationwill '�'� be cleared to a minimum depth of 5 feet bgs with a hand auger or air knife/vacuu truck equipment prior to drilling. Once cleared, the boring will be advanced using direct-push drilling equipment to an approximate total depth of 16 feet bgs by licensed drilling contractor. The exact depth of the well will be identified by the depth at which groundwater is encountered. The drill rig will be equipped with 4-foot acetate liners and continuous soil samples will be collected and logged for stratigraphic characteristics and field screened for the presence of volatile organic carbons (VOCs)using a photoionization detector(PID). Monitoring Well Construction Upon completion of the bore hole to approximately 4 feet below encountered groundwater(the expected depth to water at the site is approximately 12 feet bgs), a \\ pre-packed monitoring well constructed with 2-inch-diameter schedule 40 polyvinyl chloride(PVC)casing with 5 feet of screened interval of 0.010 inch slotted PVC at the base of the well will be placed in the borehole. The pre-packed monitoring will have No. 2/12 Monterey Sand packed around the screened interval and contained within stainless steel mesh. After the monitoring well has been placed in the borehole, the drilling rods will be pulled to one foot above the top of the sandpack to �� ! (� allow formation materials to collapse around the sandpack and riser pipe. This will create a barrier between the screened interval and the bentonite and grout used to seal the well. A hydrated bentonite slurry seal with a thickness of one foot will be placed above the sandpack. The remainder of the annular space will be grouted with neat cement to approximately 6 inches bgs. The well will be fitted with a locking well cap and completed with a traffic-rated 12-inch diameter flush-mounted well box that will be labeled as a monitoring well. Monitoring Well Development After a minimum of 72 hours following installation, the newly installed monitoring well will be developed using a combination of surging, bailing and pumping. A surge block will be moved up and down across the screened interval to remove fine-grained deposits from the formation near the monitoring well, boring wall, and from the filter material.After surging the monitoring well, a pump and/or bailer will be used to remove water containing suspended sediments from the casing. Additional purging Page: McD Island Well Install WoVan_Fina1.000 4/8