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provide easy access of pond water into the subsurface. <br />The toe of the dam was constructed on a filter blanket of <br />coarse gravel, and should provide adequate drainage for any <br />seepage within the dam. There was no evidence of seepage at <br />the toe of this filter blanket, although colluvium at the toe <br />of the dam was quite wet in the area of the previous stream <br />channel. <br />During recent months, Homestake Mining Company personnel <br />have noted two seeps of water along the channel downgradient <br />of the tailings dam. Samples of the seepage were found to con- <br />tain over 50 mg/l cf cyanide. Provision was made to capture <br />the seepage and return it to the tailings impoundment. Home- <br />stake personnel had been concerned about the seepage, as it <br />might influence possible dam stability as well as contribute to <br />ground water pollution. <br />At the time of the reconnaissance, seepage was occurring <br />along two stream channels, approximately 100 yds. downgradient <br />of the dam toe. The left hand or western of these two occurs <br />at the upstream end of the major channel, while the eastern <br />seep occurs along the north face of a west -trending stream chan- <br />nel. In addition, there was ample evidence of ground water <br />moving into a ditch, approximately 3 ft. deep, constructed by <br />Homestake Miring Company to bury the return line for pumping <br />seepage back to the impoundment. The combined flow of the two <br />seepages totaled a head of 2.75 inches in a 900 V -notch weir <br />improperly installed by the U.S. Forest Service. This trans- <br />lates to a flow of approximately 28 gallons per minute. It <br />-4- <br />