Restaurateur Seema Prasad has composted food waste since her high-end farm-to-table restaurant Miel opened about nine years ago in Nashville, Tenn.
At first, she brought food scraps to her farm, where she grew ingredients for the restaurant. Now food waste is picked up by a hauler who feeds a local composting facility.
But Prasad thinks she can do better.
She’s building a new anaerobic digester composting facility in Nashville that not only diverts food waste from the region’s landfills by turning it into usable compost and liquid fertilizer for local farms, but also captures the methane gas that is produced, using it for energy. The energy will be used to run the facility and will contribute electricity to the city’s grid.
Restaurant food waste runs to 11 million tons, or $25 billion, annually, according to one study. In Miel's kitchen, a tub is kept under the convection oven to capture waste.
Scheduled to open in late 2018, Prasad’s new facility will be one of 40 to 50 anaerobic digester facilities across the country that many see as the best solution to the growing problem of food waste because of the methane gas captured.
Another 500 composting facilities across the country offer a diversion of food from landfills to create nutrient-rich compost, without necessarily utilizing biogas.
The National Resources Defense Council, or NRDC, estimates that nearly 22 percent of disposed municipal solid waste is food. Food waste poses a serious threat to the environment.
Food in landfills decomposes and produces methane gas, a significant contributor to climate change. Landfills are responsible for a third of all methane emissions in the U.S., according to the Environmental Protection Agency.
The U.S. wastes an estimated 63 million tons of food per year, at a cost of about $218 billion annually. About 17 percent of food waste occurs at restaurants, amounting to about 11 million tons of food, or $25 million annually, according to the nonprofit ReFED, which published a “Roadmap to Reduce U.S. Food Waste by 20 Percent” in 2016.
In Nashville, food waste comprises about 30 percent of what ends up in landfills, Prasad said.
She knows that because the city has been working with the NRDC to become a model for sustainability, and such metrics are carefully tracked. Last year, the mayor gave restaurants a “food-saver challenge,” asking them to spend at least 30 days following a program designed to reduce the amount of food sent to landfills.
About 55 restaurants participated. They measured food waste from both the kitchen and what customers put in the garbage. They adopted new purchasing, storage and right-size cooking practices. They took a roots-to-leaves and nose-to-tail holistic approach to ingredients, and they donated surplus food that wasn’t served.
But despite zero-waste efforts, some food scraps still ended up in the trash. The final line of defense in diverting food from the landfill was composting.
A composting culture
It’s a movement that is spreading across the country.
Composting is the norm among restaurants in cities like San Francisco, Boulder, Colo., and Seattle, where food waste recycling is mandatory and there is infrastructure to support it.
Some states have mandatory food waste diversion laws, including Massachusetts, California, Vermont and Connecticut, according to Jeff Clark, program director of Conserve, the National Restaurant Association’s resource for creating “greener” businesses. But restaurants only have to comply if they produce more than a certain amount of waste.
There are also voluntary programs. Conserve estimated that in 2017, about 14 percent of restaurants were composting.
As part of the Food Waste Reduction Alliance, the NRA has been working with ReFED to develop a Restaurant Food Waste Action Guide, due in February, that will include waste diversion tactics, including composting.
Restaurants can find a composting facility near them at the website findacomposter.com.
Darby Hoover, a senior resource specialist in the NRDC’s food and agriculture program, helped develop the Nashville initiative and said policy makers are realizing how important it is to address the amount of food going into landfills.
“If you look at the municipal waste stream, food is still the largest component of what’s going into landfills. It’s a big material, weight-wise, which is often how we pay for waste to be managed,” Hoover said. “If cities are looking to reduce costs, they’re going to have to look at food.”
Chris Cochran, executive director of ReFED, sees composting eventually becoming as common a practice for restaurants as recycling oil for biofuel.
The challenge is that composting requires a more complex infrastructure. There are permitting obstacles and a NIMBY element in some communities, he said.
For Prasad, building an anaerobic digester has taken more than five years. She has backing from a local investor, as well state and corporate grants.
The plan is to collect food waste from hospitals, schools, manufacturing facilities, food banks, residents and, of course, restaurants.
Having composted for nine years, Prasad knows it can be tricky. Her restaurant is freestanding, so she’s able to accommodate a bin, but restaurants that have shared trash services or unaccommodating landlords might not have the flexibility.
There’s also a cost involved. Prasad said her monthly trash costs are about $212, and it costs another $130 per month for weekly food waste pick-up.
In some cases, restaurants could negotiate better rates for trash if they are reducing the amount of garbage by diverting food waste to composting, she said.
In the kitchen, however, establishing composting practices is “super easy,” she said. It’s really just a matter of putting out buckets and educating staff about what to collect.
“It helps when you have a chef that gets it and is leading by example — that’s huge,” she said. “We also manage our resources really well. We donate food. We feed our staff well.”
It has helped that the industry is becoming aware of the problem of wasted food, although, at times, when she starts talking to people about capturing methane gas from rotting food, “people look at me like I have three heads,” she said.
“But I just keep coming back to the fact that we know better now. We know this is a bad activity, putting food into landfills,” she said. “There are solutions out there. Why not just do it?”