Few concepts cause as much confusion as biodegradability (or degradability). Popular culture has led many to believe that burying the nation’s waste in landfills is sort of like creating big compost heaps, and eventually all the waste will just go away. In fact, modern landfills are designed to minimize the breakdown of waste. So contrary to popular belief, most garbage does not readily biodegrade in them. Instead, a large plot of land is filled with a community’s waste (except construction debris and hazardous materials)—once filled, the space is covered and often utilized as an airport, a park, or another function.
Many plastics do not biodegrade to any significant degree, while some do so very slowly if exposed to air, water and light—these are best recycled or used for their stored energy. Some plastics have been engineered to biodegrade reasonably quickly in a large composting facility that intentionally accelerates biodegradation in a highly controlled environment using copious air, water and light. These plastics also will break down eventually if left alone in the environment—but much more slowly since the environment does not “intentionally accelerate” biodegradation. However, similar to other biodegradable materials, they likely will not break down in modern landfills.