How South Korea puts its food scraps to good use

Around the world, most of the 1.4 billion tons of food thrown away each year ends up in landfills. As it rots, it pollutes water and soil and releases massive amounts of methane, one of the most potent greenhouse gases.

But not in South Korea, which banned food scraps from its landfills nearly 20 years ago. Here, the vast majority is converted into animal feed, fertilizer and fuel for heating homes.

Food waste is one of them major contributors to climate changenot only because of the methane, but because the energy and resources put into production and transportation have also been wasted.

South Korea’s system, which keeps about 90 percent of discarded food out of landfills and incinerators, has been studied by governments around the world. Officials from China, Denmark and elsewhere have visited South Korea’s facilities. New York City, which will require all residents to separate their food waste from other waste next fall, has been observing the Korean system for years, a spokesman for the city’s sanitation department said.

While a number of cities have similar programs, few if any other countries are doing what South Korea is doing on a national scale. That’s because of the cost, said Paul West, a senior scientist at Project recording, a research group studying ways to reduce carbon emissions. Although individuals and businesses pay a small fee to dispose of food waste, the program costs South Korea about $600 million a year, according to the Ministry of the Environment.

Nevertheless, Mr West and other experts say it should be followed. “South Korea’s example makes it possible to reduce emissions on a larger scale,” he said.

South Korea’s culinary tradition often results in uneaten food. Small side dishes — sometimes a few, sometimes more than a dozen — accompany most meals. For years, almost all of those leftovers went into the ground.

But the country’s mountainous terrain limits how many landfills can be built and how far they can be from residential areas. In 1995, the government introduced mandatory paper and plastic recycling, but food scraps continued to be buried with other waste.

Political support for change was driven by people living near landfills complaining about the stench, said Kee-Young Yoo, a researcher at the government-run Seoul Institute, which has advised cities on how to deal with food waste. Since stews are a staple of Korean cuisine, discarded food here tends to have a high water content, meaning greater volume and worse smells.

“When all that was lost, a horrible stench came out,” said Mr. Yoo.

Since 2005, it has been illegal to send food waste to landfills. Local governments have built hundreds of facilities to handle it. Consumers, restaurant owners, truck drivers and others are part of the network that ensures it is collected and turned into something useful.

At Jongno Stew Village, a popular lunch spot in the Dobong district of northern Seoul, pollock stew and kimchi jjigae are the bestsellers. But regardless of the order, Lee Hae-yeon, the owner, serves small side dishes of kimchi, tofu, cooked bean sprouts, and marinated perilla leaves.

Customers can help themselves more and “people will take more than they are going to eat,” said Mr. Lee. “Koreans like to opt for abundance when it comes to food.”

Mr. Lee pays a price for that: about 2,800 won, a little over $2, for every 20 liters of food he throws away. Leftovers go in a bucket in the kitchen all day and at closing time Mr. Lee empties it into a designated bin outside. On the lid, he puts a sticker he bought from the borough – proof that he paid for the removal.

In the morning, companies hired by the district empty those bins. Park Myung-joo and his crew start rolling through the streets at 5 AM, tearing the stickers off the bins and dumping the contents into their truck’s tank.

They work every day except Sunday. “Waiting even a day would cause huge amounts of waste to pile up,” said Mr. Park.

Around 11am, they arrive at Dobong’s processing facility, where they unload the muddy mess.

Debris – bones, seeds, shells – are picked by hand. (Dobong’s factory is one of the last in the country to not automate this step.) A conveyor belt carries the waste to a grinder, which shreds it into small pieces. Anything that cannot be shredded easily, such as plastic bags, is filtered out and burned.

The waste is then baked and dried. The moisture goes into pipes that lead to a water treatment plant, where some of it is used to produce biogas. The rest is purified and discharged into a nearby stream.

What remains of the waste at the processing plant, four hours after Mr. Park’s team has dropped it off, is ground into the final product: a dry, brown powder that smells like dirt. It is a dietary supplement for chickens and ducks, rich in protein and fiber, said Sim Yoon-sik, the facility’s manager, and is given away to any farm that wants it.

Inside the plant, the strong odors adhere to dust and hair. But outside they are hardly noticeable. Pipes run through the building that purify the air through a chemical process before the exhaust system blows it out.

Other plants work differently. In the biogas plant in Goyang, a suburb of Seoul, the food waste – nearly 70,000 tons per year – undergoes anaerobic digestion. It sits in large tanks for up to 35 days while bacteria do their job, breaking down the organic matter and creating biogas, mainly consisting of methane and carbon dioxide.

The biogas is sold to a local utility company, which says it is used to heat 3,000 homes in Goyang. What remains of solid matter is mixed with wood chips to make fertilizer, which is given away.

Every ton of food waste that rots in a landfill emits greenhouse gases equivalent to 800 pounds of carbon dioxide. researchers have found. Turning it into biogas cuts that in half, says Lee Chang-gee, an engineer at the Goyang plant.

Critics note that South Korea’s program, for all its benefits, has failed to achieve one of its goals: getting people to throw away less food. According to data from the Ministry of the Environment, the amount of food thrown away across the country has remained more or less stable over the years.

The system has other shortcomings. Complaints are scattered: In Deogyang, a district of Goyang, residents of a village said the smell from a processing facility was once so bad that they couldn’t leave their windows open. The plant has been shut down since 2018 due to protests from neighbours.

“When the factory shut down, all the problems disappeared,” said Mo Sung Yun, a 68-year-old resident of Deogyang.

But most plants across the country — unlike the landfills they essentially replace — have received few, if any, serious complaints from neighbors. Government officials say the ever-improving technology has led to cleaner and more efficient operations.

It has also made disposal easier for many. In apartment complexes across the country, residents are given cards to scan every time they throw food waste into a designated trash can. The bin weighs what they threw into it; they receive a bill at the end of the month.

“The garbage cans have become cleaner and smell less,” says Eom Jung-suk, 60, who lives in such a complex.

Ms. Eom has never been charged more than a dollar for the service. In April, she paid 26 cents. But the monthly bill makes her more aware of how much she throws away.

“Today, at breakfast, I told my daughters to take just enough to eat,” she said.