[tremoloqui]

How about re-framing the problem?

Considering:

Reclamation and recycling technology will improve over time. Similarly the economics of processing recycled material are likely to make it more valuable.

and:

Supposing we can protect the surroundings, water table etc.

further:

Supposing, as other comments have pointed out, the availability of land is not really an issue.

Then:

Is it crazy to think that there is value to be found in safely storing this material until it is more feasible / valuable to process?

At least it seems like a better plan than incinerating it.