>and subsequently leaving it there permanently in massive tailing ponds

Not permanent. They can be reclaimed, but that usually doesn't happen for many years until after the end of life for the mine.

Reclamation does not un-concentrate the materials found in the impoundment. Typically a "Mine Plan of Operations" which includes the reclamation plan is a contouring of the topography and vegetation. Some mines require indefinite groundwater treatment due to leaching from tailings ponds or other mine activity. The cost responsibility for this _indefinite_ process is sometimes borne by the state following bankruptcy of a mine.