It is safe to drink tap water in Japan. It is absolutely drinkable.
You can use it for bathing, cooking, washing, dishing… all sorts of thing.
Why We Can Drink The Tap Water in Japan
Japan has a very strict water resources control and has over 30 laws on water. And the Japanese government announces a series of standards relating to water-purity and regulates enterprises’ drainage. Moreover, each individual local government places high importance on the water resources.
Hence, the tap water is drinkable and also we have water tank inspections quite regularly at each apartments.
Some Methods to Drink Tap Water Better
1) Cool the water with ice cube or putting in a fridge
By cooling the water under 20C, the chlorine won’t give so distinctive smell. Generally it is said that water tastes better when it is 20-25C cooler than a human body’s temperature.
2) Boil and cool the water
If you don’t like the chlorine smell, it is better to cool off boiled water for 5 minutes or so, which results in a better taste. But if you do this, the water won’t chlorinate and propagate germs in the air. You should drink it up as soon as you can.
3) Reserve the water over a night or add some lemon juice drops
By reserving the water in a big pan or wide-mouthed container over a night, or adding some lemon juice drops, the water tastes much better.
Useful Information for Water in Tokyo
Tokyo Sewerage Museum “Rainbow”
Open hours: 9:30 AM – 4:30 PM
Closed on Mondays / New Year’s Holiday
Bureau of Sewerage Tokyo Metropolitan Government Web Site