How Composting Can Solve Our Methane And Plastic Problem

Back in 1996, one of California's oldest waste collection companies, Recology, began collecting food scraps from San Francisco's central market to compost. Now, the company's green composting bins are ubiquitous on the streets of the city, which has composted more than 2 million tons of food and other waste.

Recology and the city of San Francisco stand out for accepting one of the largest varieties of items for compost, including compostable packaging and almost all types of food scraps. With about one-third of all food in the United States going to waste, composting could and should play a bigger role in municipal waste systems across the country.

Food is the most common component of landfill garbage, making up 24% of all landfill material, according to the U.S. Environmental Protection Agency. In addition to the obvious social-economic concerns about food security, the massive amount of food and other organic waste in landfills is the third-largest source of human-produced methane emissions in the United States — after the fossil fuel and animal agriculture sectors — making up 14.5% of total methane emissions.

Cutting methane emissions, which the United States and the EU promised to reduce by 30% by 2030 at last year's COP26 climate summit in Glasgow, has emerged as a key factor in slowing down the warming of the planet.

Composting, in which food and other organic waste are combined with wood chips and other natural fibers to decompose in an oxygen-rich environment that does not produce the methane that develops in the anaerobic conditions of landfills, is critical to this mission.

In addition, the end product of composting, soil rich in nutrients, can help solve the ongoing challenge of agricultural soil erosion, which degrades soil quality and reduces crop yields. The nation is on track to lose the equivalent of 300 years of soil by 2100 if nothing is done. That is eight times the amount of topsoil lost during the devastating Dust Bowl of the 1930s.

But most of the nation's compost facilities are still focused solely on yard waste, like raked leaves, cut grass and garden clippings. Only 10% take food, and a smaller number take packaging. This can, and must, change — but the real question is how.

Such a change can happen through a combination of factors. Composting must become an integral part of municipal waste management systems, similar to recycling. This requires cooperation between the public-private sector, which we have seen for the past three decades in San Francisco.

Bringing Compost into the Waste Management System

Only 4% of households in the U.S. are served by composting services that pick up the waste. This number needs to grow — substantially in order to reduce methane emissions — and so do the categories of items that are acceptable for composting.

While home-composting and private services no doubt play an important role, it is only by being part of the standard waste-management and waste pickup systems that composting will reach its full potential. After all, part of the reason recycling became more mainstream was because it became part of municipal waste management systems over the years. Today, more than 59% of U.S. households have curbside recycling pickup alongside regular garbage pickup. The same needs to happen with composting.

But we cannot rely on composters alone to make the changes necessary in order to serve more consumers. Accepting food often requires composters to have certain permits and specialized equipment. And many composters say they don't have the resources for the extra sorting that comes along with accepting food, as food scraps often arrive mixed with pieces of packaging and plastic that must be separated out and discarded because they can't be composted.

City governments, which usually oversee garbage collection and waste management, can help create the sort of composting facilities that can accept these items. An example of this beneficial cooperation can be seen in Seattle, which for years has been working with composting company Cedar Grove to collect food from city residents. Not only does food get composted, reducing methane emissions, but the business has grown and flourished since partnering with the city.

Such cooperation is critical for moving composting forward in other places. For example, even though California's law banning food waste in garbage disposal has come into effect this year, some large cities like San Diego and Los Angeles still lack the pickup services and facilities to handle the growing demand for compost. These facilities and waste management companies are relying on an influx of government money to make the needed upgrades.

At the same time, while their initial rollout is challenging, policies banning the disposal of food waste are an important tool for integrating compost into waste management. In both California and Vermont, which introduced similar laws in 2020, compost beyond yard waste is growing both as a business and a public service. After all, the reason why most composters are still so focused on yard trimmings is due to bans on those in landfills decades ago.

The Role of Labeling

One of the main reasons that Recology and some other California-based composters accept not just food but also items like compostable plastic bags and packaging is due to laws and regulations about labeling.

Labeling laws also need to be specific and correlated to science to avoid greenwashing and prevent non-compostable products from contaminating the composting process and final product. Such laws are most developed in California but are gaining popularity in other places, including Oregon, where there is currently a proposal for a "Truth in Labeling" law that will help clearly designate what kinds of packaging can be put into the compost.

Clear labeling also paves the way in the public education process about what is compostable and what is not, a key factor in bringing composting into mainstream waste management.

Labeling not only makes things easier for consumers and composters but ensures continued demand for the end product in the agricultural sector. With the right facilities, regulations and municipal cooperation, food and compostable packaging are benefits, rather than a challenge, for composters.

Adding more food and packaging to the composting mix will not only reduce methane and other greenhouse gasses but will also result in higher volumes of nutrient-rich end products that farmers can purchase and use in their fields. Making this happen should be a high priority for cities.

If left alone, the immense amount of food in landfills will continue to produce increasing amounts of greenhouse gasses, and compostable plastics, if simply thrown out, will not actually break down properly, adding to the microplastic problem in our soil and oceans.

Developing the composting infrastructure to handle things like food and compostable packaging would immediately reduce greenhouse gasses and could, potentially, also be a turning point for the plastics industry, encouraging more innovation and use of compostable materials to turn one of the world's most challenging types of waste into one of the most viable — and valuable.

(Michael Waas is vice president for North America at TIPA)