Seoul says tap water at all tested sites meets drinking water standards

The Seoul Metropolitan Government released its "2025 Arisu Quality Report," disclosing the safety of the city's tap water to residents. More than 5,400 water quality tests conducted over the past year — covering water treatment centers, household faucets and public facilities such as libraries — found that all tested sites met drinking water quality standards.

The Arisu Quality Report, published annually, covers the full process of ensuring safe tap water, from test results to supply chain management, and is written to be accessible to the general public. This year's edition further broke down how water quality information is presented so residents can more easily understand the current state of water management.

To that end, test results were organized into three categories: production (water treatment centers), supply (faucets) and public facilities (including public libraries). All tested sites met drinking water standards — 5,208 residential faucets, 192 sites in areas with aging distribution pipes, and 25 public libraries.

The report also details supply chain management efforts to maintain water quality from treatment centers all the way to the tap. Last year, the city flushed 783 kilometers of water pipes and worked to replace 13,271 km of aging pipes — a maintenance rate of 99.9% — along with indoor water supply pipes, covering the full scope of post-production supply management.

The report also includes practical information residents can use in their daily lives, such as how to apply for a free water quality test, how to check faucet water quality data in their neighborhood, and how to drink Arisu safely and at its best.

The city has expanded the number of water quality test items from 357 to 362 and strengthened disclosure of water quality data from representative faucets, broadening the information residents can access directly. In line with this commitment to greater transparency, the city plans to continue reflecting updated water management policies and results in future quality reports to deepen information sharing with the public.

The Seoul Metropolitan Government launched a comprehensive Arisu summer preparedness plan in June to guard against heat waves and heavy rainfall. The city conducts year-round, around-the-clock monitoring from source water through the treatment process to distribution reservoirs to guard against the growth of microorganisms as water temperatures rise.

"We will continue to expand the information we provide so that residents can easily check Arisu's water quality and management status and use it with confidence," said Ju Yong-tae, head of the Seoul Arisu Headquarters.