Value Village ／ Before you come to Japan
This answer is a draft. It stays unpublished until legal review and source verification are complete.
Travellers from places where tap water is avoided often assume the same applies here. Japan's water is regulated to a published standard of more than fifty parameters.
Under Article 4 of the Water Supply Act, tap water must meet the Ministerial Ordinance on Water Quality Standards. The standard lists 52 parameters since 1 April 2026: 32 relating to human health (from general bacteria to formaldehyde, plus PFOS and PFOA added in 2026) and 20 relating to the water's properties (zinc through to turbidity).
In April 2024, responsibility for water supply moved from the Ministry of Health, Labour and Welfare to the Ministry of Land, Infrastructure, Transport and Tourism (infrastructure) and the Ministry of the Environment (water quality) — the first such reorganisation in 67 years. The Ministry of the Environment's current page lists 52 parameters following a 2025 revision that added PFOS and PFOA, in force since 1 April 2026.
[Verify] Confirm the current parameter count (51 vs 52) and the 2025 revision on the Ministry of the Environment's page before publication.
It is ordinary to drink tap water, use it for cooking, and fill a bottle from it. Many public facilities provide drinking fountains.
Source water and treatment differ by area, so taste can differ. Meeting the standard and tasting identical are not the same thing. Local utilities publish their own results.
Taps in some facilities are marked as not for drinking. If a tap says it is not potable, it is not.
Natural water sources are not treated supply. Do not assume they are safe to drink.
Convenience, temperature and personal preference are all reasonable reasons. The point is that it is a choice, not a requirement.
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https://www.env.go.jp/water/water_supply/kijun/kijunchi.html
https://www.env.go.jp/content/000334172.pdf
https://www.mlit.go.jp/statistics/file000004/html/n2745c01.html
⚠️ Editorial note: the source URLs above were identified by search. Our working environment cannot reach go.jp domains, so the contents have not been checked against the text. Verify every source before publication and record who checked it and when.
What we share here are ideas and everyday practices passed down among people living in Japan, together with general information drawn from public sources. They are not official recommendations, and they are not professional instruction. Practices vary between households and regions.
This is general information. Results vary from person to person and depend on your own conditions and surroundings.
Please decide for yourself, using your own judgement, whether any of this suits your situation. We cannot accept responsibility for any damage, loss or injury arising from following this article.
This article is not intended to diagnose, treat, or prevent any condition. If you have specific health concerns, please consult a healthcare professional.
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