Waste Series: Part 3: Composting

by Mia de Castro

July 24, 2020

Next, in this series, I want to discuss composting as a method of reducing waste. Composting is less popularized than recycling even though it also has some amazing benefits and is not that difficult. I hope to answer the following questions: What is composting? What are some basic rules/guidelines to composting? Why should we compost and what are the benefits?

When we compost, we separate and keep organic materials that can be added to soil to help plants grow. The composting process allows naturally occurring bacteria and fungi to break down the organic matter creating a nutrient-rich soil called compost. The soil becomes more nutrient and fertile, and composting allows food scraps or other organic materials to be repurposed, instead of simply thrown away.

Composting is generally easier than recycling as guidelines for what can be composted are usually less strict. There is no need to sort the organic material by type, unlike recycling which needs more sorting/awareness by type of recyclable.

According to the EPA, all composting should include 3 basic components: browns, such as dead leaves, branches and twigs; greens, such as grass clippings, vegetable/fruit scraps, and coffee grounds; and water for ensuring good compost development.

Compostable Items

• Fruits + vegetables

• Egg shells

• Yard trimmings

• Coffee grounds + filters

• Tea bags (unless the bag is plastic)

• Nut shells

• Shredded newspaper*

• Cardboard*

• Paper*

• Grass clippings

• Houseplants

• hay and straw

• Leaves

• Sawdust

• Woodchips

• Cotton + wool rags

• Dryer + vacuum cleaner lint

• Hair + fur

• Fireplace ashes

*Oddly enough, these materials can be BOTH recycled and composted; whether they are recycled or composted depends on the water content. If these materials are dry and whole, they should be recycled. If they are wet and/or shredded, they should be composted.

Non-compostable Items

• Black walnut tree leaves or twigs

• Coal or charcoal ash

• Dairy products and eggs**

• Diseased or insect-ridden plants

• Fats, greases, lards, or oils**

• Meat or fish bones and scraps**

• Yard trimmings with chemical pesticides

• Pet wastes**

**Much like recycling, composting can have rules that differ locally. Check local regulations for these materials. (You can do this by doing an internet search for “local composting” or “[insert city name] composting”).

You can either backyard compost or indoor compost, depending on your preference. Backyard composting is ideal if you plan to reuse your compost for gardening purposes. Otherwise, you can easily indoor compost without attracting odors or insects. (If your compost begins to smell, add more “browns” to balance out the greens.) Specific compost bins are available at hardware or homeware stores. If you live in an urban area, there are often green compost bins from which the city will collect compost, making it easy to indoor compost.

The main reason to compost is to cut down on landfill waste, and specifically, to limit GHGs released from landfills. About 30% of landfill waste is food scraps and yard trimmings that can instead be composted. Although these items are biodegradable, landfills cause anaerobic decomposition as a result of the tons of trash continually being compounded on top of one another. This anaerobic decomposition leads to the release of methane gas, a GHG 84 times more potent than CO2. Despite landfill technologies designed to capture this methane gas, it is much more efficient and safe to compost the waste before it reaches the landfill.

Moreover, composting creates healthier soil that is in less need of fertilizers or pesticides, whose chemicals can harm plants or animals. The processing of fertilizers and pesticides, as well as the transporting of extra waste that can easily be composted, require carbon emissions, so composting reduces one’s overall carbon footprint.

Ultimately, composting is an excellent option for easily reducing one’s carbon footprint with numerous benefits such as limiting GHGs and one’s waste production.