Recology’s composting crusade

It takes a different kind of mindset to embrace the unconventional. So, perhaps it shouldn’t be much of a surprise that the city synonymous with the counterculture would be the one to reconsider how waste is collected and processed.

Back in the 1990s, the city of San Francisco conducted a series of waste characterization studies in hopes of reducing the city’s landfill volumes and improving its recycling rates. The results showed that much of what was getting collected and sent to landfill consisted of compostable material. In an effort to handle this material in a more conscientious way, the city partnered with San Francisco-based Recology to come up with a strategy for collecting and composting food scraps and yard trimmings.

In 1996, Recology began collecting food waste at the San Francisco Wholesale Produce Market. Within two months, Recology expanded its organics collection program to include meal prep and plate scraping waste from large hotels in the city. Around the same time, the company invested in building a compost facility outside the city to convert this new waste stream into nutrient-rich soil.

In 2001-‘02, the program gained more steam as Recology rolled out a voluntary curbside organics collection program across the city. Then, in 2009, city officials passed an ordinance requiring all properties in San Francisco to recycle organics, making it the first major city to implement such a regulation.

Robert Reed, PR manager for Recology, says that more than 100,000 properties in San Francisco including single-family homes, apartments and commercial buildings currently participate in the program. Over the last three years, volumes of food scraps and yard trimmings have escalated from 174,841 tons in 2017, to 179,985 tons in 2018, to 181,825 tons in 2019.

To date, the city’s organics program has helped divert more than 2 million tons of compostable material from landfill. Measured in tons collected per day, curbside composting has surpassed curbside recycling in San Francisco by volume.

Despite mandatory participation, Reed says that the majority of citizens have bought in to the program and that contamination isn’t a significant issue.

“We have done, and continue to do, a great deal of outreach and education to train customers that the composting bins are only for food scraps and yard trimmings,” Reed says. “Additionally, we audit loads our collection trucks bring to [our composting facility], and we employ zero waste specialists who work with large customers to train their employees to sort properly.

“We also work with the city in providing a lot of information about the importance of composting to San Francisco schoolteachers and students. … After learning about the environmental benefits achieved through San Francisco’s composting program, students teach their parents to compost, and the parents listen and respond. As a result of these and other efforts, curbside composting has become part of the culture of San Francisco. Everyone does it and the contamination, in most cases, is minimal.”

Processing protocols

Once Recology trucks collect the city’s organics, they deliver the compostable material to the company’s West Wing facility, which is located at the Recology San Francisco Transfer Station.

Inside, a crane operator top loads the material into long-haul trucks that take it to Blossom Valley Organics North, a large outdoor compost facility that the company operates near Modesto, California.

Recology says there are 11 steps to its composting process. Once non-compostable materials such as plastic bags and other contamination is removed, compostable material is passed through a series of zones, screens, windrows and other stages over 60 days to produce the finished product.

According to the company, it stores soil amendments such as sandy loam, rice hulls, redwood sawdust and minerals on site and uses them to make custom compost blends that match the specific needs of area farms.

Taking it to market

Most of the compost Recology makes is sent off to farms, vineyards and orchards, while some is also sent to landscape supply yards. Still, some other compost the company generates is donated to school and community gardens.

The reasons for the demand in agricultural use are many, says Reed.

“Compost feeds the microbial colonies in farm soils, which are composed of microorganisms that make nutrients and minerals available to the roots of plants,” Reed says. “Farmers call this ‘switching on the life web’ in the topsoil. Compost also softens soil, allowing plant roots to travel farther and reach more nutrients. Bigger root structure means more healthy plants and more yield. Also, good, quality compost is 50 percent humus by weight. Humus is a natural sponge that retains water from rain or irrigation. So, applying compost helps farms save tremendous amounts of water and energy.”

Reed notes that The Rodale Institute, which has been conducting organic agriculture research since 1947, has demonstrated through more than 30 years of side-by-side field trials that farms can grow 30 percent more food in times of drought by farming naturally with compost.

Additionally, Reed says that many farms and vineyards in Northern California use Recology compost to grow cover crops such as mustard that pull carbon out of the atmosphere and sequester it in the soil.

“Combining the two actions—collecting food scraps in cities to make compost and using it to grow carbon-fixing cover crops—is a new approach. This hybrid program is a highly effective way to return carbon to the soil where it belongs,” Reed says.

Recology’s composting initiatives and its benefits were recently highlighted in the documentary, Kiss the Ground, that debuted on Netflix on Sept. 22. In the documentary, Reed professes the benefits of composting for helping eliminate carbon-producing organics from landfill while simultaneously helping farms produce fertile crops and soils capable of sequestering atmospheric CO2.

If embraced on a more macro scale, this type of circular approach to waste has the capacity to help curb climate change while supporting thriving farms, Reed notes.

“The unfortunate reality is that most trash gets incinerated or sent to a landfill. … There are continents and other really large regions that are getting hit with a double whammy of higher temperatures and drought. This kills soil. It kills life. One of the solutions to that challenge is to collect food scraps from cities like San Francisco, turn it into compost and get it onto local farms,” Reed says in the documentary.

The importance of taking action hits close to home for Reed, who notes meaningful change is needed sooner rather than later.

“Major news agencies reported last week that 7 of the 10 largest fires in the history of California have occurred since 2017. Climate change is very real,” he says. “San Francisco’s curbside composting collection program and using San Francisco compost to grow more food, support food security and grow crops that sequester carbon deep in the soil is a model program that should be replicated around the world.”

Spreading the seed of hope

What started out as an audacious initiative to help maximize San Francisco’s landfill space has become a model for how other communities might approach organics diversion.

“San Francisco’s composting collection program needs to be replicated in every large city on the planet,” Reed says. “One key is infrastructure. We need to plan, permit and build more compost facilities. That will give cities a place to send their compostable material.”

The interest in Recology’s composting program from outside parties has been substantial. Reed says that delegations from more than 130 countries have traveled to San Francisco over the last 10 years to learn firsthand about San Francisco’s recycling programs and the benefits that can be achieved through implementing a food scrap composting collection program.

However, more than the buy in from municipalities and government officials that is needed to change how organics are handled, is the will of the community as a whole, Reed says.

“San Francisco has reinvented the way it does trash,” Reed says. “We don’t treat it as garbage. We view and manage materials for what they really are—important resources. San Franciscans across the city share this perspective. They know that when they put food scraps in curbside composting bins, they are keeping materials out of the landfill and reducing landfill gas emissions. And increasingly, San Franciscans understand that when they compost at the curb, they help turn local farms and vineyards into climate sinks. In this way and others, San Franciscans are doing their part to try to slow climate change, and people here feel good about that.”

The author is the editor of Waste Today and can be contacted at aredling@gie.net.