Is Korea’s tap water safe to drink?

Anglerfish, which feed on a wide range of matter, are known to sometimes gulp down trash with their oversized mouths. In March 2024, one was found at a seafood market with an entire plastic bottle lodged inside it. Courtesy of Kim Byung-yup

“I personally prefer tap water. I’d say bottled water is as good as dead water.”

That is the view of Choe Jae-cheon, a leading animal behaviorist and biologist and emeritus professor at Ewha Womans University. This would mean that, according to him, Evian, the globally recognized French bottled water brand, and Samdasoo, Korea’s famous Jeju volcanic bedrock water, are ultimately no better than Seoul tap water.

Choe firmly believes that however pure the original source may be, water cannot help but lose its freshness after spending months in plastic bottles during distribution.

From an environmental standpoint, the message is a welcome one. The bottled water industry is among the world’s major polluters, producing a gargantuan volume of plastic waste, and Korea is no exception. Greenpeace says more than 5.6 billion bottles of mineral water were used in the country in 2020 alone. Assuming each bottle measures 10 centimeters in diameter, lined up end to end, they would circle the Earth 14 times.

Bottled water harms the environment not only after it is consumed, but also in the very process of being made. Its plastic containers, produced from oil-based materials, generate substantial carbon emissions and take 400 to 500 years to break down. Some of that plastic is also known to make its way back into the human body as tiny fragments, and when they drift into the ocean, they are eaten by fish and passed along the food chain until they eventually reach the ultimate predator — humans.

Workers sort plastic recyclable waste collected from households at the Suwon Resource Circulation Center in Suwon, Gyeonggi Province, on Monday, two days ahead of Earth Day. Newsis

In that sense, if tap water is indeed as safe to drink as Choe says, it could be a viable alternative to bottled water — one that helps cut plastic use and ease the environmental burden. But many people still hesitate to drink straight from the tap. The question lingers: Is it really safe?

Tap water vs. bottled water

Choe’s answer is yes. He points to a growing body of research suggesting that tap water may be safer than bottled water. In one recent Ohio State University study comparing samples from four treated drinking water plants and six bottled water brands, for example, researchers found far higher concentrations of plastic particles in bottled water.

On average, one liter of bottled water contained around 6 million micro- and nanoplastic particles, roughly three times the 2 million found in treated tap water.

That may be the case in Ohio, some might argue. But in Korea, tap water — particularly Seoul’s Arisu — has met all 303 World Health Organization standards for drinking water quality and has also been certified by the United Nations and the International Organization for Standardization.

Judges evaluate entries at the Berkeley Springs International Water Tasting. Yonhap

The quality of other Korean tap water sources has also been recognized. Tap water from K-water’s Miryang treatment plant ranked fourth, behind entries from Canada and the United States, at the 2023 Berkeley Springs International Water Tasting. Earlier, tap water from the Cheongju plant placed seventh in the same competition in 2012.

Does that mean tap water is now in the clear? Well, not entirely. To determine whether it is truly safe to drink, the entire process needs to be thoroughly examined from streams and dams to the tap in one’s kitchen.

Transmission to individual homes

Here is how tap water reaches an individual home in Korea. The process begins with intake, where raw water is pumped from rivers, dams and reservoirs, including the Han, Nakdong and Geum rivers. It is then transported by pipeline to water treatment plants, where it goes through purification, a process that involves settling and filtering out sand and other particles, as well as removing odor-causing substances and trace organic matter.

The water is then disinfected with chlorine before being sent to regional storage sites known as distribution reservoirs. From there, it enters the supply stage, traveling through distribution pipes to individual buildings and finally reaching the tap through internal plumbing.

Broadly speaking, the process up to the distribution reservoir stage can be described as the wholesale supply process overseen by the Korea Water Resources Corp., while the final distribution stage can be seen as the retail stage managed by local governments.

Yeosu’s Dundeok Water Treatment Plant, home to the nation’s largest advanced water treatment facility. Courtesy of Yeosu city

Regarding the process, experts and public institutions are largely in agreement: Water in the wholesale stage is tightly managed and safe to drink.

“We are continuing to expand advanced treatment facilities that remove organic and other chemical substances from water,” a Korea Water Resources Corporation official said, adding that only a minimal amount of chlorine is used in the disinfection process and that the level does not affect human health.

The transmission system, too, is considered low-risk for contamination. “The corporation uses large transmission pipelines, and because their wide diameter allows for very fast water flow, contaminants have little chance to accumulate inside,” said Koo Ja-yong, a professor of environmental engineering at the University of Seoul.

Experts, however, also agree that the retail stage is where contamination risks are more likely to arise. The job of delivering water from reservoirs to individual buildings falls to local governments, but differing budget constraints mean pipeline conditions can vary widely from one area to another.

Pipelines in larger cities are generally better maintained, making tap water safety increasingly a matter of regional disparity between big cities and rural areas.

“Tap water managed by metropolitan governments is of relatively high quality, but the same cannot be said for smaller counties,” Koo said.

Aging infrastructure

One of the biggest problems is aging infrastructure. In a 2024 survey on tap water consumption by the Ministry of Environment, 34.3 percent of respondents who said they do not drink tap water pointed to contamination in old pipelines. Experts say that concern is justified.

“Considering that the average lifespan of a pipeline is about 50 years, at least 2 percent of pipelines across the country should be replaced annually,” Koo said. “In reality, the replacement rate is below 1 percent. That is severely inadequate.”

Workers replace water pipes in Seoul. Courtesy of Seoul Metropolitan Government

Another potential source of contamination is the piping inside individual buildings. In Korea, the most commonly used materials are stainless steel, polyethylene and zinc-coated steel. Among them, zinc-coated steel pipes may become more problematic over time, as the galvanized coating can gradually peel off and mix into the water.

“Since 1994, zinc-coated pipes have been prohibited by law, so buildings that received approval after that year are likely to use PE or stainless-steel pipes,” said the official at the corporation.

Taken together, the findings suggest that tap water in major cities, including Seoul, is generally safe to drink. But uneven water quality across regions makes it difficult to say the same of Korea as a whole. For the government, the task now is to reduce the quality gap between urban and rural areas.

Finally, for anyone curious whether the tap water in their home is drinkable, the government provides free water quality inspection services open to all. After you apply, local government officials will come to your home, examine the water and notify you of the results.

This article from the Hankook Ilbo, the sister publication of The Korea Times, is translated by a generative AI system and edited by The Korea Times.