Laserfiche WebLink
24 July 2012 <br /> AGE-NC Project No. 10-1801 <br /> Page 4 of 5 <br /> 3.2. PRESSURE GROUTING <br /> AGE is proposing to decommission monitoring wells MW-1, -2, -3A, -SAB, -8A, -9BCD, - <br /> 10ABCD, -11B, -12A, -1 3AB, -19AB and extraction wells EW-1, -2, -3, -4, -5, -6A, -7AB <br /> and -10A by pressure grouting techniques (Table 1; Figure 2). Pressure grouting services <br /> will be provided by AWA. <br /> Prior to pressure grouting abandonment activities, wells will be checked for total depth and <br /> integrity using a Solinst water level meter. Any obstructions found in the well will be <br /> removed. <br /> Thereafter, well boxes and monitoring well caps will be removed to expose the above <br /> referenced well casings. The well heads will be fitted with a pressure tight adapter <br /> connected to a hose extending from a grout mixer. A standard grout mixture will be <br /> pumped into the well casing under approximately 15 pounds per square inch (psi) of <br /> pressure. The pressure will be applied for a minim of 15 minutes to allow for grout to <br /> penetrate the area outside of the well casing. The well will then be over-drilled to <br /> approximately 3 feet below surface grade (bsg) using 8.25-inch diameter hollow stem <br /> augers, and a 20-inch diameter stainless steel concrete cutter attachment.The top 2.5 feet <br /> of the well casing will then be cut and removed and grout will be used to fill the boring to <br /> approximately 0.5 feet above the top of the well casing. The remaining borehole will be <br /> backfilled to surface grade with neat cement and covered with either concrete or asphalt, <br /> depending on the surrounding surface material. <br /> Soil cuttings generated during drilling activities will be containerized in a 10-yard soil bin <br /> and temporarily stored at the Flag City Shell site for future disposal to a Class II landfill (i.e. <br /> Forward Landfill); rinseate will be containerized in properly labeled Department of <br /> Transportation (D.O.T.)-approved 55-gallon drums, and stored on-site for disposal, in an <br /> area lacking public access. <br /> 3.3. 'POPSICLE' METHOD WELL ABANDONMENT <br /> In accordance with an EHD approval letter dated 13 July 2012, AGE is proposing to <br /> destroy wells MW-4A, MW-7A and MW-20A using a previously EHD approved method of <br /> well abandonment known as the `popsicle' method (Table 1; Figure 1). The popsicle <br /> method will only be utilized provided the casing can be successfully removed with the <br /> entire cement seal attached on the removed casing. If the casing is not removed entirely, <br /> then the well and boring will be over-drilled to full depth utilizing procedures as described <br /> in section 3.1. <br /> Popsicle well destruction activities will be conducted by AWA using a CME-75 drill rig <br /> Advanced GeoEnvironmental,Inc. <br />