Q. It has been my understanding that garbage in a plastic bag does not disintegrate as efficiently in the landfill as does garbage that is exposed to the elements. I understand it's cleaner during the collection process, but does that override the long-term effects?A. "The master variable that causes waste to decompose in a landfill is water," explains Robert Ham, professor emeritus of civil and environmental engineering at UW-Madison. "To the extent that a bag is secure and doesn't allow water to flow through the waste, it will slow down decomposition."
However, a bag of garbage faces a rough journey from your doorstep to the dump. Garbage trucks contain compaction mechanisms, which usually tear or burst bags as they compress the trash. Once at the landfill, the waste is spread into layers and run over multiple times with a compactor, a heavy machine with cleated wheels.
"The chance of a bag surviving all of this intact is about zero," Ham says.
A ripped garbage bag will still slow the decomposition process slightly, he says, but any detrimental effects should be "pretty much inconsequential."
-- Produced in cooperation with University Communications
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