When the Grouse Creek Mine opened in 1995, it was hailed as an example of mining done in harmony with the environment. But the central Idaho gold mine closed in 1997 because it wasn’t making enough money, and its 500 million-gallon tailings pond leaks and has been contaminating streams with cyanide. Now federal and state officials say the pond must be drained.

Hecla Mining Co. plans to treat the pond, located at the headwaters of the Salmon River, in order to remove cyanide, mercury, cadmium, silver and copper. The mining company will then discharge the wastewater into a so-called mixing zone, where officials say it will be diluted by water in the river.

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