Sending unused food down the garbage disposal instead of dropping it in the trash can might seem like the more eco-friendly option. The truth is that the Earth might just be better off with your table scraps heading to a landfill.
Why? Along with the added electricity and wasted water that is necessary to run the disposal and flush the particles down the drain, the wastewater treatment process is heavily dependent on energy. Even the most efficient plants still devote the majority of their energy to the treatment of solids in wastewater.
The Fox Metro Water Reclamation District, along with many wastewater treatment plants in the United States, uses what is called an "activated sludge" process to treat its wastewater. The simplified explanation of the process involves using microorganisms that either consume particulates or attach to them allowing the solids to settle to the bottom of the treatment tank. Then, the partially cleaned water that remains on top is removed for further filtering and purifying.
This sounds like a very environmentally friendly option until further examination of the process is done. The organisms require large quantities of oxygen to live and this is provided using motorized bubblers. According to a study by the North Carolina Water Works & Water Environment Association, 60% of the energy consumed by wastewater treatment plants is for the aeration of activated sludge, and another 12% is used to pump wastewater from homes to treatment facilities.
While this whole process does keep little bits of your table scraps from ending up in a landfill, it consumes an enormous amount of energy with a carbon footprint much bigger than carrot peelings.
- Save Scraps. Vegetable scraps such as celery tops, onion skins, and carrot peels are perfect for the stock pot. Keep them all in a gallon-size zip-top bag in the freezer until you have enough to boil. Toss breads out to the birds. Spread coffee grounds out in the garden or sprinkle on the grass, they make an outstanding fertilizer.
- Compost. By keeping all of your food scraps at home, there are no transportation costs for your waste. Toss all of your scraps (except meat scraps) into the pile and occasionally add a layer of grass clippings or dead leaves to balance it out and keep pests out.
- Trash. If you're not going to save your scraps, you're better off tossing them in the trash. The bits will decompose in a landfill and you'll spare the wastewater plants the extra energy consumption.