Check the water

To the Journal editor:

There’s a fair amount of fussing in the air concerning water to be disposed of by Lundin at the Eagle Mine.

One aspect is concerned with the quantities involved, and where they come from. Another is the quality of the waters, before and after treatment.

Nobody seems to be concerned about the strong possibility that a sudden collapse of the mine structure would drain the wetlands, the aquifers and the Salmon Trout river very, very quickly.

That possibility was brought up in the court proceedings which began in 2006, and again many times since then, but it has been studiously ignored by Kennecott, by Rio Tinto, by Lundin and by the regulating agency, the Michigan Department of Environmental Quality.

I haven’t heard from the insurance people yet. Our basic contention was that the design data for the mine had been fudged, and that can be proved easily, provided that the regulating agency and their courts do not collude in the fraud.

But there is the safety issue. If mined as planned the structure has a safety factor lower than one, and is therefore predicted to be unstable. Currently ignored.

The plan is to handle the situation by mining upward, assessing conditions as they go, and stopping if conditions so indicate. That sounds halfway practical except that they refuse to learn from case histories.

Not far away, near Negaunee, the Athens mine collapsed through some 1,700 feet of hard rock – and it happened overnight, on the weekend – so nobody was killed. Google will bring you several well-written accounts.

The current operators’ claim that the geology there is different from that at the Eagle is in part correct, but in the most crucial aspect they are wrong, possibly fatally wrong.

At both operations the stressfield (forces holding the rock together) is tensile, tending to pull apart). That at the Yellow Dog has been so described in the literature. Although recommended years ago stresses have not been measured.

The long, straight, vertical dikes running the length of the Yellow Dog plains are the best indicator. They came up from great depth because there was very little compression north-south.

The collapse at the Athens mine was controlled by similar dikes, near vertical, with slippery wet contacts, allowing plug failure as soon as a certain area had been undermined.

The prognosis for the Eagle, if mined as planned, is for sudden, unexpected collapse and flooding.

Jack Parker

Mining engineer/geologist Baltic