Battle of Disposers: Trash vs. In-sinkerator

Recently, a visitor to Low Impact Living asked the following question:

Q: What is more environmentally harmful? Putting food waste down the garbage disposal, or putting it in the curb-side trash?

Based on our prior knowledge and some quick research, here was our response - we hope it might be useful to you as well.

A: Well, the answer as with most things is "depends". I'm assuming you guys are on a sewer system and not a septic tank / leaching field. If this is the case, then it is better to send it down the disposal. In the sewage treatment process, all food solids are either separated out and sent to a composting facility of some kind (or spread on fields for fertilizer) or completely digested by bacteria during the treatment process. In either case, there is little impact on whatever water body the plant discharges to. And, there can even be a positive benefit if it is used as fertilizer or if your treatment plant collects the methane produced by the bacteria and burns it for electricity (it is a renewable energy source in many parts of the country).

If it goes in the trash and to a landfill, in theory it would degrade through time. However, they compress those landfills so much that there is little airspace left in the piles and even biodegradable things will sit there for long long long times. There isn't much environmental danger, but it adds to the mass of stuff in landfills and therefore requires more of them.

If you have a septic tank, then the opposite is true. The bacteria in a leaching field, especially if it is an old one, might not fully degrade stuff and it could therefore enter some water body downhill from you as nutrients. And, even the small chunks left after shredding can plug the spaces between gravel in the leaching field and shorten the life of your system.

Longer term, there are other options at home. I'm assuming that you might already be thinking about composting, but you can compost all organic food leftovers at home. Any ordinary composter will take veggie scraps, bread, pasta, etc when mixed with yard waste and turn it into beautiful rich dirt. No smells either (we have one in our backyard, and I'm fascinated by it). Decent ones start at about $60 - $80 - we have a wide selection of composters at Low Impact Living. There are two other kinds of composters that deal with the non-veggie stuff. One shown here is called a solar cone digester - it sits in your back yard and is about $150. The design of this composter provides the right mix of aeration, heat from the sun, and protection to degrade meats and other wastes that would pose problems in standard composters.

The other is my compost dream machine. It's called the NatureMill, and it's an automated system that sits right in your kitchen. Looks almost like a fancy trash barrel, but in goes trash and out comes dirt. It's a bit pricey at $450, but is the best option if you are space-limited or don't like those trips out to the backyard in mid-January. Find the NatureMill here.

We hope you found this little tidbit helpful!

Jason Pelletier, Co-Founder, Low Impact Living