Waste management companies are only able to recycle or compost about a third of the 254 million tons of trash produced in America each year, so they're always looking for new ways to get rid of the trash we pay them to deal with.
So they start coming up with crazy notions about how to dispose of large quantities of trash quickly, typically via incineration, and what's better at incinerating stuff than a volcano, right?
Typically, volcano craters are filled with water—kind of like a mini-mountain lake—and sticking around to wait for a lava-spewing eruption would be hazardous, if not downright deadly, for garbage collectors. (Drilling down into the magma chamber isn’t much safer.)
It would also be expensive to send tons of trash to far-flung volcanoes, and we’d likely see an increase in our electric bills, since some regions burn trash in incineration plants and use the heat to make electricity.
-Via Mental Floss