Josh Doyle, 29, stopped drinking tap water after developing a stomachache the first time he drank it at his residence in Yongin, Gyeonggi Province.
The Scot had regularly drunk tap water at home. In Korea, he switched to a Brita filter.
There is no way to know whether the water caused his stomachache. But his hesitation is hardly unusual, particularly among foreigners living in or visiting Korea.
Similar concerns have surfaced among US service members. In 2024, US Army Garrison Humphreys in Pyeongtaek, Gyeonggi Province, investigated its tap water after soldiers raised questions about its safety and concluded that it was safe to drink.
Concerns resurfaced in June when a US Army soldier posted a TikTok video showing a discolored water filter from her barracks alongside a new one. โIโve always heard the water quality in South Korea wasnโt the best,โ she said.
The video drew pushback online, with some users pointing out that Korea generally has relatively soft water and low levels of limescale compared with many countries.
Experts likewise say Koreaโs tap water is generally of high quality, while calling for better management of pipes inside buildings and closer monitoring of occasional problems with source water to build public trust.
Koreaโs tap water scores well on official safety measures. Its residents are considerably less convinced.
Korea Water Resources, the state-run water management agency, says it applies the strictest standards among those set by the World Health Organization and five advanced countries of the Organization for Economic Cooperation and Development.
Its compliance rate has remained above 99.9 percent over the past five years, reaching 100 percent in 2025.
Korea also ranked relatively high on Yale Universityโs Environmental Performance Index this year, placing 24th among 177 countries for health risks associated with unsafe drinking water, behind Denmark and Israel and ahead of Japan at 29th.
However, many Korean residents also remain skeptical of tap water.
In a 2024 survey by the Ministry of Climate, Energy and Environment, 61.3 percent of respondents said they trusted the quality of tap water, compared with 7 percent who said they did not.
Yet only 4.4 percent said they drink tap water directly or after refrigerating it, while 33.5 percent said they boil it. In the same multiple-choice question, 57.1 percent said they use a water purifier or simple filter, and 34.3 percent said they buy bottled water.
The main reasons for avoiding tap water were concerns about impurities in water pipes and health concerns, cited by 34.3 percent and 21.5 percent of respondents, respectively. Another 11.4 percent said they were influenced by people around them.
โWhen I asked some foreign nationals why they do not drink tap water, I heard that even Koreans around them had discouraged them from doing so,โ said Baek Myeong-su, a researcher and executive director of the Network for Safe Drinking Water.
โIf even Koreans do not trust their own water, what can we expect from those visiting Korea?โ
Experts say Koreaโs tap water generally maintains drinking-water quality while it moves through the public supply system. The bigger uncertainty begins after it enters individual buildings.
โFor people from other countries, stomachaches can occur temporarily due to differences in mineral content or sensitivity to chlorine byproducts,โ Baek said. โBut the water is treated to a high standard to begin with, and particularly in large cities, it generally meets drinking-water standards.โ
Experts draw a distinction between the quality of water supplied by utilities and the condition of pipes inside older buildings. Aging infrastructure does not automatically make water unsafe, but poorly maintained plumbing can affect color, taste and public confidence.
The Seoul Metropolitan Government said in July that it plans to replace 111 kilometers of water pipes more than 30 years old this year as part of a long-running renewal program. About 2,710 kilometers remain on the cityโs replacement list.
โIf we assume that a water pipe has a lifespan of 50 years, 2 percent of the pipes should be replaced every year,โ Koo Ja-yong, a professor at the University of Seoul, told local media. He estimated the nationwide replacement rate at about 1 percent.
High-profile incidents involving discolored water, larvae and algae blooms have also periodically shaken public confidence, even when authorities said treated water remained within safety standards.
Experts say those episodes point to the need for better maintenance and monitoring rather than evidence that Koreaโs tap water is broadly unsafe.
Experts say the next challenge is less about proving that Koreaโs tap water is safe and more about making people believe it is.
โWater management appears to be handled well up to the public water supply system, but once water enters a building, responsibility shifts to the building,โ said Oh Choong-hyeon, a professor of environmental science at Dongguk University.
โA system should be introduced to disclose the condition of building plumbing, while budgets should be provided to replace indoor pipes in vulnerable areas and older homes.โ
Oh said producing a bottle of bottled water requires at least four times as much water as the amount it contains, adding that its production, transportation and disposal also create an environmental burden.
Baek also raised concerns about bottled water, noting that it is produced by private companies, with the government playing an oversight role rather than directly managing its production. She also pointed to the possibility of microplastics entering bottled water from plastic containers.
โPublic attention tends to focus on water only when major incidents occur, making sustained education and public outreach necessary to improve trust,โ she said.
