Municipal Composting Programs: Co-Collecting Organics with Trash
Organic waste such as paper, food scraps, and yard trimmings make up the bulk of the U.S. municipal solid waste (msw) stream. As of 2014 — the last year for which the Environmental Protection Agency (EPA) provides statistics — the combination of paper, wood, yard waste, and food scraps made up 61 percent of the total MSW we generated in the United States.
Still, around the same time, municipalities managed to recycle a higher share of lead-acid batteries and steel cans than yard waste and food scraps. Clearly, in order to move closer to a zero-waste goal, we need to institute composting programs at the municipal level.
If we want to achieve high compliance rates, we'll want to avoid dramatically changing demands on citizens. The simplest way to do that is to co-collect organics and other types of MSW together, making it as easy as possible for residents to avoid contamination.
While that may sound like a tall order, a few pioneering communities are already doing it successfully. Here are a few of the lessons early adopters have learned. These guidelines will help any community implement a successful co-collection strategy for trash and compostable materials.
Start by sourcing compostable trash bags.
Observing service providers who already offer organic collection services, one thing seems clear: Compostable bags are essential to a successful co-collection program. With the right compostable bags, residents can toss them into trash bins alongside traditional garbage bags. Then transfer-station staff simply pull the bags from the sorting belt, diverting them to an industrial composting facility or for anaerobic digestion.
So what should you look for in a compostable bag? First of all, choose bags that carry certification with the Biodegradable Products Institute. These products will feature a BPI-certified compostable label. (Search for BPI-approved products here.)
Compostable bags designed for the municipal waste system must be tough, as well. Ask your provider if its compostable bags have been tested for burst-resistance under compaction. If you plan to collect organics with existing waste trucks, the bags cannot break when they're compacted.
Finally, choose bags with a bold, easy-to-identify color. This will help keep organics and other materials separate throughout the waste stream.
Work with industrial-scale anaerobic digestion providers as well as commercial composting operations.
Given the relative paucity of composting and anaerobic digestion facilities in many communities, municipal planners have two options: They can work with the service providers that already exist, or they can build a whole new facility.
Obviously, the latter is a much more expensive prospect. But whether you're planning a new facility or choosing between existing providers, it's important to consider both anaerobic digestion and aerobic composting as solutions to transform organic waste into valuable new commodities.
Each technology benefits from different compositions of feedstock. For instance, food waste is much more valuable to digesters. According to Biocycle, food scraps can produce 100 cubic meters of biogas per metric ton. Yard waste, on the other hand, only produces 30 cubic meters of biogas with the same volume.
However, composters always need leaves and yard trimmings to get the carbon ratio right. This synergy is even more powerful if you can access a combined digestion/composting facility. Digestate left over from the production of biogas makes a great feedstock for the composter. Don't try to choose between anaerobic digestion and composting; whenever possible, use both.
Create a detailed public-education plan.
Any change in the municipal waste-collection process requires an in-depth pubic relations campaign. You're asking residents to change long-held habits, and the best way to ensure compliance is to explain the program — and the rationale behind it — clearly and through different channels.
For instance, mailers are effective with some portion of the community, but no matter how attractive you make your document, there will be residents who don't read it closely. Be sure to use social media channels and direct outreach to explain the changes to your program.
In all outreach channels, use graphics to illustrate appropriate sorting. Define organics with visual examples. Explain the environmental benefits of compliance and address common fears, such as the sense that compost always smells bad and/or attracts bugs and other pests.
Finally, educate the public about any local or state environmental goals that would encourage municipal composting.
Support waste-reduction legislation in your area.
When cities or states establish clear environmental goals, the public is already primed to accept changes in the waste stream. Take the city of Boulder, Colorado, for instance. The Boulder City Council passed a zero-waste resolution in May 2006, stating the city's devotion to "the pursuit of Zero Waste as a long-term goal in order to eliminate waste and pollution in the manufacture, use, storage, and recycling of materials."
This resolution paved the way for a curbside composting program that started in 2008. Then, in 2015, the city passed its Universal Zero Waste Ordinance, which requires all single-family home-owners to subscribe to the city-run waste-hauling service — including its organics component. Meanwhile, all businesses must keep all trash, recyclables, and compostables separate for appropriate diversion.
Some businesses complained that compostable plastic bags were too expensive, so the City used funds from a city-wide $0.10 plastic-bag fee to implement a new Green Bag Giveaway program. Currently in its pilot phase, the program gives eligible Boulder businesses a six-month supply of compostable bags for organic waste.
This is just one example of how local governments can contribute to boosting organics recovery. There will always be a political component to zero-waste goals, and few municipal composting programs will succeed without the will of the residents and the work of local activists.
Co-collection is a great way to simplify the resident's experience, thereby boosting diversion rates. In order to implement such a solution, though, you'll need to convince your community that the benefits of co-collection outweigh the costs. Luckily, composting itself is an extremely beneficial waste-handling strategy.
Explaining the Benefits of Composting
Residents won't get excited about composting and co-collection unless they understand the benefits. Every piece of educational literature about composting should remind readers of these benefits, which include the following:
- In the landfill, organics significantly contribute to the creation of the greenhouse gas methane. Composting drastically reduces methane emissions, while anaerobic digestion harnesses biogas to create energy. Both options may provide cities with carbon credits.
- Compost can contribute to carbon sequestration, creating even greater greenhouse-gas savings.
- A well-run composting program can achieve these and other environmental benefits at a cheaper cost than competing technologies.
- In fact, composting can save communities money by reducing landfilling costs. The Town of Amherst, New York saved $22.8 million between 1991 and 2009 thanks to composting, mostly due to savings at the landfill.
- Compost is a salable good. As organic farming grows in popularity, demand for compost will also increase.
- According to the EPA, compost can eliminate 99.6 percent of volatile organic chemical contaminants in polluted air.
Along with all these environmental and financial benefits, many residents say that composting makes them feel good. They are reducing waste and improving environmental outcomes. Knowing this, if municipalities can remove barriers to composting, residents are much more likely to participate in an organics collection program.
Having to drop off composting at a particular location is a barrier. Keeping separate bins uncontaminated is a barrier. With co-collection, both are removed. Any stakeholder that wishes to improve municipal composting rates, or even introduce curbside composting for the first time, should look into the possibility of a co-collection program. All it takes is the will, industrial-scale composting facilities equipped to handle BPI-certified materials, and a ready supply of compostable bags to implement co-collection of organics with trash.
In addition to the considerable benefits of any curbside collection service, co-collection simplifies operation for haulers and other city staff. A single truck can collect both trash and organics along the same route. Meanwhile, the city provides a single trash cart where they would previously need two.
Curbside composting is great for any community. When you introduce co-collecting organics with trash, though, you can achieve even greater benefits throughout the waste stream, from the source to reuse and back again.
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