Industry & Innovation
Through its development, Seoul has run into several waste management issues. Firstly, prior to the 1990s, Seoul’s waste was primarily disposed of in nearby landfills. However, with a rapidly expanding metropolis and economy, the city eventually ran out of space, turning to incineration which provides several wonderful environmental benefits.1 Incinerators, called Resource Recovery Facilities (RRF) in Seoul, are a more efficient use of space by preventing landfill sprawl by reducing the mass of the waste by up to 85%. Their use eliminates the groundwater contamination that occurs whenever it rains over landfills and in South Korea where monsoon rains are only getting worse by the year, this is significant.2 Seoul’s incinerators also create energy to heat local communities and lower the city’s greenhouse gas (GHG) emissions by 15,000 tCO2 through reducing the methane, a much more potent GHG, released from landfills.1 By 2026, the Seoul Metropolitan Government (SMG) will have constructed their fifth RRF with the hope of “zero direct landfilling” across the city that same year.3 Currently operating facilities process 2,850 tons of household waste a day.1
While overall incineration is an upgrade from landfills, it isn’t a perfectly sustainable solution. Emissions can contain a variety of toxins and heavy metals including dioxin, mercury, and arsenic2 in addition to the normal GHG culprits carbon dioxide, sulfur dioxide, and nitrogen oxides,4 contributing further to Seoul’s air pollution problem (see Fig 1). This practice is also believed to encourage the continued consumption of plastics and other unsustainable materials because a significant amount of garbage is needed to keep facilities open by generating power through its burning, preventing other more sustainable solutions from being developed like reusing or more efficient recycling.2
Processing Food Waste
However, not all of Seoul’s waste undergoes this processing. South Korean culinary culture involves a lot of side dishes and liquid-based dishes like stews, meaning that a lot of food goes to waste and is often quite pungent, and the national landscape is mountainous, preventing the construction of sufficient landfills across the nation, not just around Seoul. Finding a sustainable way to process food waste became imperative. As of twenty years ago, putting food waste into landfills is illegal, preventing 90% of today’s waste from producing methane or being incinerated and contributing to GHG emissions. Instead, most of it is converted into animal feed, fertilizer, and fuel for domestic heating through the capture of biogas.8
Separation of food waste is dealt with both domestically and commercially. Businesses like restaurants and grocery stores pay the government a little over two dollars per twenty liters of food scraps to process it for them. Payment is tracked by stickers purchased from the local district which are stuck to government provided food waste bins when they are full and ready to be taken away. Companies hired by the district come in the mornings to remove the stickers and take away the waste. In apartment complexes, residents keep their food scraps separate from their other waste and bring it down to a special holding container, a pay-what-you-throw system called a RFID machine, which measures its weight through the use of issued tap cards. At the end of the month, residents receive a bill for the weight recorded via their tap card which is rarely over a dollar a month and helps encourage residents to lower their amount of waste.5
From there, facilities that have gathered the waste pick out any plastic, bones, or shells and then grind up, bake, and dehydrate it. The removed moisture is sent to water treatment plants where some is used for biogas creation and the remaining is purified and sent back out into nature via stream. The final product is a nutrient-rich animal feed supplement that is given away to farms. Exhaust from these facilities is filtered before being released into the atmosphere. Other plants put food waste that they receive through anaerobic digestion for a month to create their biogas product, turning the remaining solids into fertilizer which they also give away to farmers. While biogas does still release carbon emissions, it is half of what is produced from food sent to landfills.5 Additionally, the SMG aims to continue to capture more food waste by distributing sink strainers and mini compost machines to residents and composters to hospitals, restaurants, schools, and cafeterias.6
Rethinking Take-Out
As of 2019, Koreans go through 96 plastic bottles, 65 plastic cups and 460 plastic bags per year and Seoul residents alone use one billion plastic cups and delivery containers per year. After the global shut down caused by the COVID-19 pandemic, Seoul residents began to heavily rely on take out food, resulting in the spike of 54 million takeout containers per month in 2021. The SMG, recognizing the sheer volume of the waste, teamed up with multiple leading delivery apps to utilize reusable steel takeout containers after a hugely successful pilot program. After their use, the containers are left outside of the resident’s doors to be picked up, the cost of this pickup and the cleaning covered by the city. From the delivery bag to the utensils, every part of the package is reusable. Additionally, a program for reusable coffee cups called Zero Cafes saw their return rates grow from an initial 47% to 80% in just a few months. Grocery stores are also notorious for the amount of plastic used in their packaging, so to combat this, the SMG has begun to open Zero Markets where items are either left unpackaged or can be dispensed into containers that the shoppers bring with them where they pay by weight. The products sold are also made of all-natural ingredients to further lessen environmental impact.7
Conclusion
Seoul’s innovative food waste processing system is so revolutionary that it is currently being studied by several other global metropolises like New York City, with the hopes of them being inspired by it and implementing their own versions. Reducing landfills through this processing of food waste and the creation of sustainable products causes less environmental issues and reduces impact on communities through the elimination of pungent smelling landfills and halved pollution. As always, this kind of innovation creates more job opportunities but more specifically more job opportunities in sustainability. Through connecting people to their practices through these waste policies and solutions, Seoul residents are able to take their own impact on the planet into their own hands. My hope is that incineration is a temporary solution while they develop more ways to turn trash into treasure.
To see a list of Seoul’s waste related assets, you can view the Seoul Asset Map here.
1Smart Waste Management in Seoul: Resource Recovery. (2014). In Seoul Policy Archive. Seoul Solution.
2Greentumble. (2018, August 2). Waste Incineration: Advantages & Disadvantages. Greentumble.