This is the issue....so much disturbance, and there is no way to collect all the runoff from snow melt/rain events.
The amount of water that will get treated (with limited success) in comparison to all the runoff is insignificant. Therefore we are left with a giant, ever-increasing problem of Selenium accumulation that will continue for centuries.
Is the benefit of making steel with a cheap heating fuel greater than a legacy of selenium pollution?
There is already technology available for making steel that does not use metallurgic coal....it just costs a bit more.
We are not making any new mountains or rivers.
The value of clean water is only going to go up as this messy planet ages