Composting: Recycling Our Food

sites/default/files/compost_cycle_0.jpgUntil recently more than 90% of what ended up in the garbage cans at the Ferry Plaza Farmers Market was compostable. Those resources, when not captured for composting, were wasted and contribute to greenhouse gases instead of renewing soils. Now all compostable items discarded in the green bin at the Ferry Plaza Farmers Market joins the materials of many San Francisco households and restaurants at the Jepson Prairie composting facility. Our new Waste Wise initiative will divert an estimated 78 tons of compostable materials from the landfill annually!

What is compost?

Compost is formed when organic matter (material that comes from plants or animals) decomposes aerobically (with oxygen). The resulting nitrogen- and carbon-rich substance can be added to soil to improve its structure, provide and hold soil nutrients, prevent erosion, and encourage beneficial insects and microorganisms.

Why compost?

When compostable food scraps and yard debris are sent to the landfill, not only are their valuable nutrients wasted, but they can actually cause environmental harm. In the landfill, organic materials decompose anaerobically (without oxygen), releasing methane, a greenhouse gas that is 23 times more potent than carbon dioxide. Landfills account for 34% of methane emissions in the United States. Meanwhile, America is losing its soil fertility and topsoil at alarming rates. When food scraps are recycled, either in a backyard compost pile or as part of a municipal composting system, they are turned from waste into a resource and used to enrich gardens and agricultural lands.

In San Francisco, that’s exactly what’s happening when you put your orange peels, biodegradable forks, and coffee cups in the green bin. Every day, the city sends about 300 tons of compostable materials to Jepson Prairie Organics composting facility in Vacaville. The materials are screened to remove contaminants (mainly plastics) and spread out in long windrows. A mere 60 days later, the materials have become compost. This compost is used on productive lands throughout the Bay Area, including some farms that sell at the Ferry Plaza Farmers Market. Capturing the organic resources from the market and redistributing them to farms offers a tidy and elegant solution to the waste problem: your coffee cup could end up becoming part of your tomato!

What’s compostable?

Composting is not as hard as you might think. If it is food or a food-related paper product, it can go in the green bin. Plastic straws, cup lids, and other plastics are not compostable, so please take a moment to remove these items from their partner paper products. Breaking up isn’t always easy, but in this case, it is the right thing to do. When the green bin gets contaminated with too much non-compostable plastic, we have to throw the whole thing in the garbage! For your reference, here’s a list of what’s compostable:

All food

fruit, vegetables, meat, poultry, seafood, shellfish, bones, rice, beans, pasta, bread, cheese, and eggshells, oyster shells, burritos (without foil wrappers), etc.

Food-soiled paper

waxed cardboard, napkins, paper towels, paper plates, paper cups (without lids) paper milk cartons, tea bags, coffee grounds/filters

Plants

floral trimmings, tree trimmings, leaves, grass, brush, weeds

Biodegradable food serviceware

This includes paper plates, paper coffee cups, and “bio-plastics,” which look like plastic but are made out of corn, soy, potatoes, or other organic materials.

How do you tell the difference between plastic containers and cutlery and the compostable look-alikes?

Many of the new compostable to-go containers in use inside the Ferry Building, at the farmers’ market, and throughout the Bay Area look like plastic, but they are made from corn or other biodegradable materials. The easiest way to tell the difference is to check the bottom of the to-go ware container for labeling. Some are compostable; others go in the recycling bin.

If it is compostable, it will say “Compostable” or “PLA” and you can put these in the green bin. Sometimes these compostable items (such as the cups from Alive! Restaurant) have a green stripe to make them easier to identify.

Disposable cutlery may also be compostable, but unfortunately, forks, spoons and knives are rarely labeled as compostable. If you are unsure, check with the vendor who gave you the cutlery or bring it to a Waste Wise station for assistance.

 

About CUESA

CUESA (Center for Urban Education about Sustainable Agriculture) is dedicated to cultivating a sustainable food system through the operation of the Ferry Plaza Farmers Market and its educational programs. Learn More »