Laserfiche WebLink
MIMIEngineers Al <br /> Planners �� 9 <br /> Economists �� 01ST & <br /> MMMI Scientists <br /> WORKPLAN FOR ABANDON?dENT OF WELL <br /> mcCOSTOCK 0 ORNIA <br /> As part of the ongoing field work at the McCormick and Baxter <br /> Wood Treatment Facility in Stockton, California, well A-9 will be <br /> abandoned in accordance with California Department of Water <br /> Resources Bulletin 74-81 . The well is located adjacent to the <br /> treated pole wash pit near the center of the McCormick and Baxter <br /> property. This letter outlines the procedures for abandoning <br /> well A-9 , and serves as a general workplan for well abandonment <br /> at the McCormick and Baxter site. <br /> WELI, CONSTRUCTION <br /> Well A-9 (originally called well B-9) is 38 feet deep, with the <br /> bottom 15 feet consisting of machine slotted well screen (See <br /> attached figure) . The well is constructed of 4 inch inside <br /> diameter (ID) steel casing, placed in. a 12 inch ID borehole. A <br /> 3-7/8 inch submersible pump that was originally installed in the <br /> well has been removed. No above ground protective casing <br /> currently exists above this well . <br /> ABANDONMENT PROCLDEIR-Lia <br /> Well abandonment will be accomplished by overdrilling the well <br /> with 12 inch outside diameter (OD) hollow stem augers. The <br /> entire well casing and screen will be removed from the borehole, <br /> and the borehole will be filled with grout to the ground surface. <br /> The following general well abandonment procedure will be used: <br /> o The hollow stem augers will be steam cleaned prior to <br /> drilling . <br /> o The augers will be centered over the casing, and the well <br /> will be drilled out to the bottom of the original borehole. <br /> Drilling will continue until the entire length of the <br /> original borehole is redrilled, and the augers penetrate <br /> native soil . <br /> o A winch will be attached to the top of the casing, and the <br /> casing will be pulled up through the augers. The casing may <br /> be cut off after every 20 feet, and the winch reattached to <br /> the remainder of the casing. <br /> o Either neat cement, or a grout of Type II portland cement <br /> and no more than 5% bentonite powder, will be mixed with <br /> clean water, to form a slurry. The grout will be pumped <br /> CH2M HILL Son Francisco ONfce 61:25 Christie Avenue.Suite 500 415.652.2426 <br /> Emeryville, CA 94605 <br />