The Myths of Biodegradation
|Biodegradable products are the preferred environmental solution because waste simply biodegrades in the landfill.|
|Nothing biodegrades in a landfill because nothing is supposed to.|
In the 1991 book Rubbish!: The Archaeology of Garbage, Dr. William Rathje of the University of Arizon summarized his innovative techniques of excavating modern landfills as a method of observing human social activities. Among his findings: the dry and oxygen-poor conditions found in modern landfills cause organic matter to mummify rather than decompose.
This fact is actually preferred since uncontrolled biodegradation in a landfill can cause ground water pollution, methane gas emissions, and unstable sub-soil conditions. As a result, modern landfills are kept dry and air-tight to prevent biodegradation. Read the EPA website page on modern landfill design.
This fact sheet from Environment Industry Plastics Council (Canada) also gives an excellent overview about why biodegradation in landfills is not a solution.
Composting, on the other hand, is the process of controlled biodegradation outside a landfill.
By carefully controlling the feedstocks (source-separated, mixed organics), and controlling the process (moisture content, oxygen levels), composters transform biogegradable materials into useful products that are used in farming, gardening and soil conservation.
Today, despite national progress on yard waste composting, more than 60 million tons of biodegradable materials (food scraps, wet & soiled paper, leaves and grass) are still being sent to landfills where they will sit in an airless, dry environment to be mummified.
The phrase biodegradable, like recyclable, merely describes the composition of a product. Its potential, not its inherent value. If a product is sent to a landfill, and not disposed of properly in a municipal composting or recycling facility, it is still part of the problem no matter what it's made from.