Unironically, to dispose of complicated* wastes well, you want to find some place that groundwater doesn't really drain out of, then put all the waste in a deep pit there, ideally sheltered from wind. Then you leave it for the future archaeologists or prospectors to find.

*Anything that's not compostable, combustible, or practically recyclable.

But you don't want to do this within 100 meters of a living space, and definitely not as a Groverpit right underneath your foundation!