'However, what has been separated away, roughly 90% of the whole ore, causes environmental problems if left around and has to be processed and stored in large tailings dams. This is potentially the biggest environmental issue of the whole treatment process, since basically they have to be stored forever and not allowed to dissolve and leak out into the environment. This is done successfully presently in Sudbury and other places, so yes it can be done, but for sure pretty rigorous environmental assessments have to be met before permits are provided"
This is why underground mining and tailing backfill of shafts and drifts are, although more expensive, also more ecologicaly protective, and will become over mine life a more cost efficiant way of desposing of waste. This in turn will be a more logical way of mining as the footprint in the wetlands will be smaller and less invasive. Big aboveground pits are expensive to water infiltration protect and have the need for large mountains of waste overburden storage. This overburden can be replaced into the open pit as the pit moves out of ore areas but with many years of above surface storage wind damage and leaching can be much more damaging. Noront has taken the better approach to the envirorment over profit and as such should reach permit stage quickly.