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Memo to Oehler BMRI Abatement #8 Submittal page Z not retrieve samples of saturated material. As a result the tailing samples were constrained to unsaturated material with little of the potenti lly interactive pore fluids. It appears this equipment constraint inappropriately limited BMRI's sampling and characterization of the tailings. The report contains an explanation of the history of tailings depos lion within the Upper and Lower Tailings Ponds from the April 1991 f cility start up through March of 1993 when the final fluid sample was collect d. Briefly summarized, at the time of sampling on November 10th through I th, 1992, the Upper Pond contained only pre-violation tails (April '91 -Jan ary '92). However these tails had been exposed to hydrogen peroxide whic was added to the standing pool of fluid in the summer of 1992. Six sh llow holes (Holes #1 - #6) were angered (sia feet or less in depth) in the Upp r Pond tails and no in-situ fluid samples were collected. These shallow to Is may have been invaded by the hydrogen peroxide treated fluids, whic may have modified their chemical constituency. No information was collecte regarding the migration of high-WAD fluids through these tails, or the affects of subsequent exposure to hydrogen peroxide treated fluids. In contrast, the Lower Tailings Pond had commenced its operation l life identically to the Upper Pond, receiving pre-violation, AVR-treate tails from April of 1991 through April of 1992. Following the NOV issu nce, BMRI commenced CYTOX treatment of the tails entering the Lower Pond on Apri17, 1992, at which time the tailings beach had reached an ele ation of approximately 8551' amsl. On June 15, 1992, BMRI commenced h drogen peroxide treatment of the standing fluid pool in the Lower Pond, hile continuing tails treatment with CYTOX. On June 15, 1992 the Low r Pond tailings beach had reached an elevation of approximately 8555' a~sl. The addition of CYTOX was discontinued through October of 1992. On ovember 6, 1992 hydrogen peroxide treatment was discontinued in the Lo er Pond. On November 15, 1992 the INCO Air/S02 reactor became operatio al, at which time the tailings beach had reached an elevation of approxi ately 8562' amsl. BMRI completed auger sampling of the Lower Tailing Pond at seven (Holes #7 - #13) locations on December 16th through 19th, 1992. During March of 1993, at the suggestion of the Division, BMRI subs quenlly drove an additional hole (#8.5) and collected one in-situ fluid sam~le for analysis.