In ,
harry wrote:

I snip to what Harry just wrote, in expectation that he said enough

When it was in it's originally place, the geology had stabilised over
millions of years. Once you bury it in a manmade hole that is not the
case. It could be accidently disturbed, flooding could expose it,
excavations for building work , it can contaminate ground water.etc.
Buried industrial waste ia a problem even today.
Not to mention the extensive contamination of the sites where it was
mined from. There are vast amounts of construction waste
contaminated with asbestos and vast amounts still in buildings that
will be a problem for years to come, especially where to dispose of
it. Do you want it buried in your neighbourhood?

Put hazardous waste in a manmade hole well into a rock formation with a
50-milion-year-plus track record of stability, and I would not worry about
it.

If the waste was asbestos or plastic products, then the requirement is
even milder. Bury it where there is low expectation of the rubbish being
outright unearthed by earthquakes. Asbestos is only bad to those who
inhale it and has a high rate of being bad only for those who inhale
substantial quantities of it (mostly as in visible clouds). Plastic
products are *at-least* pretty-much only bad to what eats them.

--
- Don Klipstein )