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<br /> <br />June 2, 2000- Clear water was observed flowing out of the riser at an approximate rate of <br />5 gallons per minute. Possible water sources: return flow from north decant, flow from <br />around the steel riser, or flow into the pipe at grout holes # 2 or # 3 which washed out <br />unknown quantities of slurry grout prior to setting of the grout. <br />June 5, 2000- Cleaned & replaced drain plates or bricks at the tower. Reinstalled grout <br />casing into decant line at hole # 3. Water level tests initially indicated that 7-8 feet of <br />water was detected above the pipe at Grout hole # 3. Water flows were noticeably <br />reduced. (3 inch casing installed into 3 %i' hole in the decant.) Hole was air tested and <br />ultimately verified interception of decant, as water was displaced at riser tower, which <br />lowered the water table at the riser & exposed~a boil at ground level around the riser. <br />June 6, 2000 -Discussions held regazding new scenario. Decision made to locate north <br />decant line such that low mobility grout plug could be installed. Decision made to re-drill <br />grout hole # 2 for installment of low mobility plug. <br />June 7, 2000- Hole # 2 re-installed. Small void detected, which seemingly verified water <br />infiltration theory through access holes in the pipe at locations # 2 & #3. <br />Hole # 14 was drilled in an attempt to intercept the north decant line to no avail. Hole # <br />15 was moved to the North 2 `. Hole # 15 (Grout Hole # 4) encountered the North <br />decant at 10'. Grout was detected in the decant, however a void of approximately 10 <br />inches was discovered. <br />June 8, 2000- Pumped 2.5-3.0 yard plug into grout hole # 2. At the crown of the pipe, an <br />additional 15 cubic feet of grout was installed to seal grout hole #2. Operations were then <br />___ moved to the riser tower. 7.5 yards of low mobility grout was injected into gout hole # 4. <br />Upon completion of the grout plug, massive water flows were detected at the riser. <br />Ironically, only minor displacement occurred during the grout plug installation. <br />June 9, 2000- Bricks on the tower were raised by DG/HB personnel. Mill personnel <br />raised brick level even higher in an attempt to equalize the suspected water level. <br />June 12, 2000- Sluny.grouting commenced at grout hole #3. Water was displaced during <br />operations. Grouting continued until: sand & water boils around the riser pipe were <br />stopped, when grout was measured in the riser itself, and when pressures exceeded 200 <br />psi. Approximately 20 yards of slurry was injected into the pipe. 1.5 yards of grout was <br />injected at the crown of the pipe to seal the access hole. <br />June 15, 2000- No detectable flows have been observed. <br />