Abandons the property? That would mean the bond never gets returned. And the environmental plans HAVE been approved. They deal with the old settling ponds. That work has already been started, last September. The cost IS known. It is negligible, compared to the bond.
It entails placing sand and tailings over the old pond floor, a new non-permeable liner, and covering the liner with more earth. (A layered series of sand, rocks, and topsoil, all planted with new wild grasses. Even the type and amount of grasses have been determined.)
You have a lot of catching up to do, P. I suggest you go to the DRMS website and start reading the documents there. It will answer a lot of the assumptions you are making.
The links are in the stickies above.
Good luck.