Jokal...

Although the tree destruction is an issue ,the biggest issue for mining is the tailings debris,left overs from mining..In copper mining ,for every ton of copper mined there is 99 tons of waste..and gold mining is worse..and uranium mining is worse still..

This derbris or tailings are nasty stuff full of acids..heavy metals..natural poisons such as arsenic and it may take hundreds to thousands of years for some waste dumps to become "acid neutral" and stop leaching to the environment.

This is part of the expense of doing business.

From the Elliot Lake mine ,which was active in the 40's-50's,it is still costing money for people to monitor,and clean up after the mining process.

so it is the most expensive issue in mining I would think..

Portee