Garbage Foundation - Wild Speculations

I've always wondered what we can do about solid waste or garbage.  We're piling up tons and tons everyday with no foreseeable end.  And I'm just thinking, why can't we compress them really well and make them foundations of buildings?  I'm sure there are arguments related to liquid waste seepage or instability of material.  Or it could be the other way around with ground water seeping into the foundation.  But isn't it tempting?  For example, the Empire State Building's foundation is said to be 55 feet.  That's garbage for an entire neighborhood. 

Imagine master planning an entire city and you take out tons of soil and use compressed garbage instead.  Perhaps you can construct a small hill from the displaced soil which can house all the trees in the metropolis.  How visual would it be if Green Hills had an actual hill in the middle? 

You can raise the land level.  Think about how thankful people can be if you raise Malabon by 30 feet.  That should be worth a couple of hundred thousand tons of garbe use right there.  It could also work for reclaimed areas. 

Will it make the foundation unstable?  Maybe.  So why not make the digging a couple of meters deeper.  Is my theory right?  Deeper foundations are more stable?  If you make garbage your foundation, perhaps the tons of pressure would hasten the degradation of the garbage. 

Here's a wild thought.  Perhaps we can fill up an entire denuded valley with garbage.  Once you have that flat surface, cover the entire expanse with garden soil and then start your reforestation effort there.  So unlike in buildings, you don't expect anything to collapse.  Most of the roots will still be on the soil level.  And I would guess that most of the smell that would seep out of the ground would be absorbed by the trees. 

Here's an even wilder thought.  If you have a volcano that has an imminent eruption, use tons of garbage to block the path of molten lava.  I'd say that serves a double purpose.  It can potentially block the lava or at the very least burn and bury tons of garbage.  Of course you may have to wait for 50 years or so each time you utilize this method.

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