4 incineration plants lead Seoul's household waste management

Mapo Waste Resource Recovery Plant is one of Seoul's four incineration plants. Courtesy of Mapo Waste Resource Recovery Plant

By Kim Se-jeong

From delivery boxes to toilet paper, food waste, recyclable items and plastic items ― domestic waste refers to all types of waste produced by households.

In Seoul, food waste and recyclable items are collected and processed separately and the rest is either incinerated or buried.

Mapo Waste Resource Recovery Plant is one of the four incineration plants where waste is sent and is turned into energy.

The plant processes household waste from five districts of Mapo, Jung, Yongsan, Seodaemun and Jongno. It processes an average of 600 tons of waste every day.

Hundreds of garbage trucks arrive at the plant every night and early morning and unload the waste into the waste bunker that is 3,000 cubic meters in volume.

Garbage trucks unload waste into the bunker at the plant. Courtesy of Mapo Waste Resource Recovery Plant

Three giant cranes pick up the trash and load it into three incinerators ― each has the capacity of treating 250 tons per day. Heat from combustion is made to move turbines to generate electricity and heat up water. The plant sells the electricity to the Korea Electric Power Corp. (KEPCO), and sends hot water to the Korea District Heating Corp., located right next to the plant, which distributes water to thousands of homes in the neighborhood.

A giant crane transports trash into incinerators located on the left. Courtesy of Mapo Waste Resource Recovery Plant

Toxic gas from the incineration goes through another set of facilities to filter dioxins, acid gas, heavy metals, nitrogen oxides and other pollutants before being released into the air.

"We're successfully covering all the waste from all five districts," an official from the plant said.

The incineration leaves ashes. The plant makes bricks from so-called bottom ashes and sells them. Light fly ash is collected and treated separately at a different location.

The plant is often a point of trouble with local residents who complain the plant is a source of pollution.

"People see the gas coming out of the chimney, especially in the winter, and complain that it's toxic gas. That's not true. It's water vapor. It is a clean process and people don't have to worry about pollution from the plant," the official said.

The city's first incineration plant opened in 1996 in Yangcheon District. Currently, Seoul's four incinerator plants ― in Mapo, Yangcheon, Nowon and Gangnam districts ― are up and running, with the capacity to process around 2,100 tons of garbage per day.

That is almost 23 percent of all waste produced by households daily. Seoul produces more than 9,400 tons of household waste every day, among which almost 30 percent is food waste and 39 percent of recyclable items. Almost 9 percent of waste is buried.

For decades, Seoul chose to bury its household waste. The current Mapo plant site used to be a major dump for the city. As the Sudokwon landfill site opened in the 1990s, the city stopped burying the waste in Mapo and turned the mountain of trash into a public park.

Seoul still needs more incinerators

The Mapo plant, along with the three others, makes a good waste management example. Compared with a landfill site, the plant doesn't need much land and is considered much cleaner.

"But the four plants can't cover all the household waste from the city," according to a Seoul city government official. Geumcheon District in southwestern Seoul takes all the household waste to the Sudokwon landfill site in Incheon to bury. Eunpyeong District has its own incineration plant but still sends part of its waste to the landfill site because its 48-ton facility is too small to cover everything.

The city started to look for sites for additional plants. On July 31 this year, the city government created a new team dedicated to finding candidate sites.

The future of Sudokwon landfill site is another reason why the city government is pushing to increase the number of incinerators.

Under the current plan, the landfill site will close in 2025.

"Given what's happening in the Sudokwon landfill site, we need to find our own solution," the official said.

Yet, it will be a big challenge to find a new incineration plant site in Seoul with strong backlash from local residents. The city already witnessed "not in my backyard" (NIMBY) movements among residents when constructing the existing plants and other waste treatment facilities.

This problem isn't only for Seoul.

"Incineration is the cleanest way possible to treat waste. This is a global trend and that's where Korea will go. But we're well aware of NIMBY and it is a big challenge for us," an environment ministry official told The Korea Times, adding that the government is currently looking for ways to make these facilities attractive to residents.

"So that they can welcome those facilities in their neighborhood. One example can be Amager Bakkie in Denmark," he said.

Located in Copenhagen, Amager Bakke incinerates waste and produces power from the heat. The building's sloping roof is also used as an artificial ski slope, hiking slope and climbing wall.

Nationwide, more than 51,000 tons of household waste is processed every day, and the country has 457 incineration plants.