Strange question, i know. I didn't really know where to put it. Why don't garbage trucks grind their garbage instead of simply compacting it? There's plenty of shaft power available in the truck to reduce the garbage into a reasonably fine consistency. This would allow the trucks to carry much more garbage on a single route and would also facilitate easier handling and landfill logistics. The garbage could be mixed with water to form a slurry and simply pumped into landfill instead of having to be laboriously moved using bobcat-like machinery. I imagine the landfill would be much more efficiently utilised in this scenario, as there would be hardly any air and wasted space within the garbage slurry. The garbage may also decay more quickly when thoroughly mixed as a thick slurry. There may also be scope for sorting useful materials from the ground garbage (pre slurry) using some mass dependent hydrodynamic or aerodynamic process and appropriate filter membranes. (Perhaps the garbage could be blown around a bend with high velocity air, with different catchment receptacles for flung particles of varying mass) Just a random thought.