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Bulldog Mine Tailings Ponds Evaluanort <br />i. Snterceptor wells were installed downgradient of the embankment in 1980, but <br />were abandoned at the end of 1980 due to sand accumulation in the wells. <br />2. A slurry cutoff wall was constructed through the near-surface alluvium <br />downgradient of the embankment in 1982, along with a drainage trench and <br />pump-back system upgradient from the slurry cutoff wall. Three monitoring <br />wells were installed down gradient from the slurry cutoff wall. <br />3. In 1983 a slurry trench was constructed along the core of the Lower Tailings Pond <br />embankment to enhance stability and to impede seepage, along with installation <br />of associated piezometers to monitor pore water pressures. <br />After discharge of tailings to the Lower Tailings Pond ceased in 1985, cyanide concentrations <br />and ground water levels in associated monitoring wells and piezometers gradually declined. The <br />Lower Tailings Pond was reclaimed in 1993 and associated monitoring wells and piezometers <br />were plugged and abandoned. <br />The Upper Tailings Pond has been reclaimed in a manner similar to the Lower Tailings Pond. <br />Due to lower permeability materials beneath the tailings, the Upper Tailings Pond did not <br />• experience the seepage issues or require the related remedial construction work listed above for <br />the Lower Tailings Pond. <br />• <br />Nonret~ake blining Company' Shepherd .l/filler, lnc. <br />p~u-s N~mdfrLg.pn ~ dprrl 1 J. 1997 <br />