Geological strata vs shallow landfill sitting above aquifers and subject to near-term erosion.
Disposing of this stuff in deep mines seems like it'd be fine, unfortunately we haven't yet, at a society/economy level, found the discipline to do so. Presumably after a few mya of heat and pressure it'll be indistinguishable from other petrochemicals (which aren't particularly nice to begin with).
I don't think disposing of stuff deep in mines would be a good idea as it would be easy to contaminate the ground water. Modern landfills are generally well engineered and don't contaminate the surroundings too badly.
Geological strata vs shallow landfill sitting above aquifers and subject to near-term erosion.
Disposing of this stuff in deep mines seems like it'd be fine, unfortunately we haven't yet, at a society/economy level, found the discipline to do so. Presumably after a few mya of heat and pressure it'll be indistinguishable from other petrochemicals (which aren't particularly nice to begin with).