Municipal composting has increased, but what does that really mean?

“If we did nothing else to change our food system — if we didn’t stop overproducing food or stop food waste earlier in the supply chain — and we just composted, we would be cutting out an enormous source of methane emissions coming from landfills,” says Danielle Melgar, food and agriculture advocate at Public Interest Research Groups. “Composting is really attractive for that reason.”

In 2023, there were 400 municipal composting programs servicing 710 communities, representing a 49 percent increase since 2021 in the number of households in the United States with access to municipal food scrap collection.

New initiatives may help those numbers continue to rise. In January, the U.S. Department of Agriculture allocated $11.5 million in funding to composting and food waste reduction projects in 23 states through the American Rescue Plan Act. And late last year, the Biden administration released a draft food waste reduction strategy that called for expansion of community composting programs and municipal infrastructure with the support of federal agency funding.

Different cities, different compost

Although all municipal composting programs share the goal of diverting food waste from the landfill, communities take different approaches to implementation.

Currently, there are four types of municipal composting programs: “opt-in,” which requires households to register to use the service; “standard,” in which curbside collection is offered as part of the municipal solid waste program; seasonal collection that can be added during the months when yard trimmings collection begins; and mandatory composting, enforced by fines.

Some cities offer curbside compost collection for free to every household, while in others, residents must opt in for a fee. These can vary widely depending on where they live: The fee to participate in curbside composting in Alexandria, Virginia, is $21 per month, while residents of Falls Church, Virginia, pay $8 per month. And many cities, even those that already have curbside services, also fund programs through which residents can drop off their compost at designated sites like community gardens and farmers’ markets. Chicago, for example, rolled out its first-ever Food Scrap Drop-Off program in late 2023. And New York City has both curbside food waste collection — rolling out citywide over the course of 2024 — and longstanding “community composting” programs, funded by the city and facilitated by neighborhood partners and organizations like GrowNYC.

In addition to taking different approaches to collection and fee structure, cities also differ in their handling of food scraps. Most cities that collect food waste turn it into nutrient-rich compost, which is used in municipal sites like parks and community gardens, according to Nora Goldstein, composting expert and publisher of BioCycle, a publication that covers recycling and composting. But some cities send food scraps to anaerobic digesters to be turned into biogas. In New York, food scraps dropped off at community gardens and other community collection sites are composted — but the food waste collected through the new municipal curbside programs is not. It’s a controversial move.

Organic materials account for 30 percent of the waste generated and landfilled in New York. Curbside food waste, and food waste collected through 250 so-called Smart Bins around the city, is transported to wastewater treatment plants and mixed with sewage, undergoing a process that transforms it all into biogas — a methane-based fuel that can be used for home heating. But there have been hiccups.

“If you send the food scraps to a digester that does not preclude — after a lot of the energy is captured — taking the digestate to a compost site,” says Sally Brown, research professor of environmental and forest sciences at the University of Washington. “But New York has a lousy biosolids program. They get some energy out of the food scraps, but they’re not using the final product and they’re emitting a lot of greenhouse gases.”

New York City has hailed its success in diverting food scraps from the landfill, but the Institute for Local Self-Reliance (ISLR), a nonprofit that provides technical assistance to support sustainable community development programs, notes in a 2023 report that more than half of the leftover solids from the wastewater treatment facilities go to landfills and incinerators — not “land application” like compost for parks and gardens. The ISLR report determines that these kinds of programs “aren’t composting — they’re greenwashing.” And recent budget cuts, which defunded eight community compost programs, are expected to see even less of the city’s food scraps turned into compost.

Benchmarking success

Even in cities where organics collection is free and convenient, participation in municipal composting programs is often low. On a national level, some data shows that participation ranges from 100 percent of households in some municipalities to fewer than 30 percent in others.

San Francisco; Seattle; Boulder, Colorado; and Portland, Oregon, are considered the gold standard for municipal composting programs. Melgar points to mandatory composting policies, widespread access to curbside composting and community composting sites and ongoing education as shared characteristics. Circularity is also important, she adds.

“Showing where the compost from the food scraps is going — to our school playgrounds, our parks, our nature preserves or our own gardens … helps people understand why it’s worth it to compost and why they should be participating,” Melgar says.

Legislation is also a key. Mandatory participation in curbside programs (with fines for noncompliance) is the least common form of municipal composting, but that is shifting as several states, including California, Vermont, Rhode Island, New York and Washington, plus cities like Laurel, Mississippi, and Austin, Texas, have passed legislation that mandates composting. It’s a model that businesses in some municipalities have been required to follow for years, but the concept of mandatory composting is still new to residential customers.