What happens to stuff I put down the garbage disposal?
-Katie K., Brewton, AL
Things you put down your garbage disposal, usually food waste, will go through your septic system, into your sewer, and on to your local water treatment plant. Of course, not all kinds of food scraps can be disposed of this way. Grease, fat, and starches like pasta and rice will clog your drain, and hard materials such as bones and fruit pits can damage the blades.
Once the pulverized scraps reach the water treatment plant, processing will filter out solid waste and send some of it to a digester tank. In the digester tank, bacteria convert the waste to biosolids and methane through the process of anaerobic digestion. In some places, these biosolids get a new life as fertilizer, while the methane can be used for energy. Other plants may send these materials directly to the landfill. Don’t be afraid to contact your local water treatment facility and ask about their process.
If your water treatment facility converts organic solid waste to fertilizer or energy, disposing of food scraps in your garbage disposal isn’t a bad option. It keeps food waste out of a landfill, where it will likely emit methane into the atmosphere. But composting your leftover food scraps is probably still the best way to make sure they break down without negative impacts. Plan ahead and eat all of what you buy, cook, or order, and you’ll have even less waste to worry about.