Wasted food makes up over 20% of the municipal solid waste stream in the United States. The majority of this wasted food ends up in landfills, with only about 4% of this food waste going to compost. This is an issue because as food decomposes in landfills it goes through an anaerobic process, during which it emits methane, a potent greenhouse gas.

Diverting wasted food and other organic matter, like leaves and grass clippings, from the landfill not only reduces greenhouse gas emissions, but it also saves resources. Following the EPA’s Food Recovery Hierarchy, food should first be reduced at the source as much as possible, then diverted to feed hungry people second, then go to feed animals third, then used for anaerobic digestion and other industrial processes fourth, and then composted fifth. The last and final sixth resort for this food waste is the landfill.

EPA's Food Recovery Hierarchy stating the different tiers from most preferred to least preferred

Let’s take a closer look at the fourth and fifth tiers of this hierarchy a little more closely. Anaerobic digestion breaks down organic matter using microbes in an anaerobic (oxygen free) environment. There are two byproducts of this process: methane and a soil amendment. The methane is captured and used for energy, while the soil amendment can be used on farms as a fertilizer.

Black covering of the anaerobic digester in front of a large blue holding tank

The fifth tier of the hierarchy is composting. Composting is something that anyone can do and it is particularly useful because it turns this organic matter into a valuable soil amendment (essentially a fertilizer). This finished product, also called “black gold,” is great to use in gardens, backyards, and even in your house plants. It provides extra nutrients that will make your plants healthier and help them grow. Composting is also beneficial because it reduces disposal costs. You can compost at home, either indoors or outdoors. To compost inside, you can try vermicomposting. Vermicomposting uses worms, typically red wiggler worms, and other microorganisms to turn your kitchen scraps and yard waste into black gold. Setting up a vermicomposting system is fun and easy!

Outdoor composting bin with wooden slats next to a tree

To compost outdoors, set up a bin that’s at least 3 ft x 3 ft x 3 ft. You can either construct one yourself (there are lots of ideas and plans online for DIY compost bins) or purchase one, such as a solar composter. Start by adding a layer of “browns,” which are your dried leaves, straw, wood chips, and other carbon materials. Next, add some “greens,” which are your food scraps, grass clippings, and other nitrogen materials. A 3 to 1 ratio of browns to greens will ensure an optimal environment for the microbes to efficiently decompose the organic matter. Make sure the compost is damp to help with the decomposition, and aerate the pile occasionally by mixing or turning to provide oxygen.

Try composting at home and watch our webinar to learn more!

CET has been a leader in wasted food solutions for over 20 years. CET designed and operates RecyclingWorks MA, the award-winning wasted food reduction assistance program in Massachusetts. CET’s Wasted Food Solutions also offers program design and implementation services throughout the Northeast U.S. and beyond, and waste reduction consulting services to provide information and advice nationally.