Do you really imagine that the waste lake left behind will be treatable, or even if it was once, that it will be treated for the number of centuries it will be a threat? The wetlands, muskegs and headwater streams that will be destroyed cannot realistically be recreated. Anyone with any time spent studying the history of mining, or fresh water biology can tell you that. I have some background in limnology. I understand chemistry. I also understand probability, statistical likelihoods based on economics, natural processes, geomorphology of areas chosen for hydro projects and the impossible nature of guaranteeing any sort of positive outcome when it comes to acid leaching over a long period of time, or containment of toxic water behind big dams. There is going to be unacceptable risk forever. I don't know what your industrial or work background is, but you brush off concerns about this sort of thing like it easy as rolling out pie dough to "mitigate" mining threats. I don't trust that.