The Radix Ecological Sustainability Center runs a program called the Community Composting Initiative (CCI). The CCI is a compost collection service for people who for various reasons lack the time, space, and/or energy to compost in their backyards. Food wastes are collected from residents and businesses on a weekly basis for a small fee and are brought to the Radix Center. Wastes are mixed with wood chips (obtained for no charge from private companies) into piles where the food scraps compost passively over a period of months.
Residents are supplied with a 2.5 gallon compost container with a carbon based filter on its lid designed to scrub out odors from the food waste. The container is lined with a compostable bag made of corn starch. The function of the bag is to keep the bucket cleaner, and to make it easier to dump the contents -particularly in the winter when food waste might otherwise freeze and stick to the sides of the container. The compostable bag is added to the compost pile along with the food waste where it degrades.
Once a week, CCI members put their compost containers on their front steps or porch where they are collected and dumped into 18 gallon plastic storage bins. Eighteen gallons is the largest size container that is used as wet food scraps are heavy and it is difficult for one person to transport and dump a larger container.
In warm weather, the food scraps are put directly into a compost pile as soon as possible. If the food scraps sit in sealed plastic containers for too long they begin to break down anaerobically, attract flies, and create excessive odors. It’s less critical to quickly process the containers in the winter. When temperatures are sub-freezing the food scraps remain frozen and can be processed at a more leisurely rate. Proper management of community-scale composting operations in cities is especially important, particularly when it comes to odors and the perception that the operation is attracting pests. Foul odors and the perception of pestilience willserve only to create a bad reputation for community composting and will result in pressure to ban composting from inside city limits.
Best practices for composting include:
- Only accepting plant-based materials from customers. It’s certainly possible to compost putrescent or animal products like meat, dairy, and cheese, but if not properly managed they can result in serious odor and pest issues. By limiting collections to vegetables, it’s possible to control the quantity of putrescent waste yet still retain the ability to occasionally compost the body of chicken or rabbit that has died. In addition to vegetables, it’s possible to accept coffee grounds, tea bags, paper towels and napkins, shredded newspapers, flowers and houseplants, hair or fur, holiday wreaths, jack-o-lanterns, and egg shells.
- Timely processing of the compost and ample additions of carbon-based materials are necessary to suppress odors. It’s always preferable to add too much carbon and slow the composting process versus having too many nitrogen-based materials that will produce odors.
- Wrapping compost piles in hardware cloth or chicken wire will inhibit access to the pile by mice or rats. If vermin are a serious issue, it may be necessary to compost in sealed containers, although this less desirable as it reduces the oxygen levels in the compost pile.
- Finally, layering straw or hay around the outside of a compost pile will create a visually appealing screen, preventing anyone from seeing food waste and making a compost pile resemble a cylindrical hay bale. An additional benefit is that the straw layer helps to insulate the pile and thereby accelerates the composting process.