Tailing ponds, cyanide

Cyanide hazards to fish, wildlife, and livestock are well documented. Massive kills of freshwater fish by accidental discharges of cyanide wastes are fairly common (Holden and Marsden 1964 Leduc 1978 Towill et al. 1978 USEPA 1980 Albersworth et al. 1989 Ripley et al. 1996). In one case, cyanide-containing mine effluents from a Canadian tailings pond released into a nearby creek... 

The breached tailings pond at the gold mine, which was 93 ha in area and about 20 m deep, was lined with a plastic membrane and held approximately 4.43 million tons of flotation solid wastes. Due to an imbalance between water burden, unexpected quantities of water from the addition of snow and rain, and safe storage volume, the capacity of the pond was insufficient to safely store the slimes. It was estimated that 50 to 100 tons of cyanide were released into the river (UNEP/OCHA, 2000). 

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