Would it be okay to just dump it somewhere in the great canyon or the rocky mountains? Would it reasonably do any harm there?
I wouldn't put it anywhere near a water table if you want to keep consuming that water.
it needs to be protected from weathering.
Yucca mountain was ideal for a lot of reasons - remoteness, stability, but I suspect there are many similar places - also mines. the good thing re: this waste vs fuel waste is it's relatively low half life will render it 'cool' in a few hundred to a few thousand years.