If you drink tap water in Japan, here’s something you need to know.

By on April 6, 2017

According to posters distributed by Japan Water Works Association (Nihon Suidou Kyokai), Japan is one of only 15 (out of 196) countries in the world with potable tap water.    (Source: Global Water Supply and Sanitation Assessment 2000 Report by the World Health Organization (WHO), UNICEF, and Water Supply & Sanitation Collaborative Council)

The other 14 countries are: Finland, Sweden, Iceland, Ireland, Germany, Austria, Croatia, Slovenia, United Arab Emirates, South Africa, Mozambique, Australia, Switzerland and New Zealand.

Japan’s tap water undergoes stringent quality control tests that meet 51 criteria to be considered safe to drink. Tests include strict control of residual chlorine quantity and removal of radioactive substances during the purification process. Restaurants, business establishments that serve tap water are required to seek approval from the Ministry of Health, Labor and Welfare before being allowed to operate.

The results of periodic quality control tests  conducted by the Bureau of Waterworks Tokyo Metropolitan Government  are open to the public.

It is no secret that in order to purify tap water, the use of chlorine is needed. Chlorine generates low levels of bacteria-busting trihalomethanes but which are also responsible for carcinogenic activity that could adversely affect the health of organs, central nerve, liver, kidney, etc.

Japan conducts periodic quality inspection through its municipalities (Water Supply Law). In 2003, the amount of residual chlorine was kept at 0.1 mg per liter in accordance to Article 17 of the Water Supply Law Regulation on Enforcement (Article 22 of the Waterworks Act).

However, very little chlorine affects the quality target values (taste and odor of water) thus, the maximum limit was later adjusted to 1 mg/liter.

Although tap water itself is safe to drink, the health risk posed by supply pipes is somewhat a cause for concern.

Up until the late 1980s, ‘naked’ lead pipes with weak resistance to rust were widely used which resulted in contaminated water.  (Source: http://www.mhlw.go.jp/topics/bukyoku/kenkou/suido/kyusui/dl/h24_03tebiki.pdf)  These naked lead pipes were thus discontinued in 1993 and scrapped from the JIS standard. They were replaced by only ‘coated’ lead pipes. (Reference: Survey by the Ministry of Health, Labor and Welfare in 2001 “Survey report on lead removal in tap water”)

In April 2003, the Ministry of Health, Labor and Welfare announced that an enormous amount of lead (exceeding 7,530 km) in pipes still remains. (Water Statistics, Fiscal year 2009).

In Japan, it is mandatory for ‘unserviceable’ tubes to be replaced by their 40th year. However, naked lead pipes are still in use in some parts of Japan. This means not only are leakage accidents caused by corrosive soil  likely to happen, these pipes’ resistance to earthquake is also conceivably low.

Despite Japan’s budget allocation for improvement, maintenance and emergency pipelines, let’s not forget that the country is essentially, earthquake-prone.

Who should take care?
Apartment or condo dwellers.  Inspection and management of water tanks in apartments or buildings is not done by the government but by a business operator with a permit from the Ministry of Health, Labor and Welfare.

Here are some helpful tips you can do to protect yourself and your family:


1. Cook only with cold tap water. Hot water directly from the faucet can contain higher levels of lead.

2. Boil water for 40 minutes to remove chlorine. (But you lose the minerals too).

3. Tap water in summer is warm. Wait until cold water comes out before drinking.

4. Many families in Japan use a household water purifier.  Although there are many brands sold in the market, the Torayvino brand (Super slim 703T) seems to be widely used in the country.  What it does is serve pure filtered water that passes through a fiber membrane and granules-activated carbon to filter out unwanted chlorine, turbidity or trihalomethanes. It uses a cartridridge replaceable every 2 months or if your consumption is no more than 10L a day. Sold on Amazon Japan for ¥1,555.  Cartridge is sold here.


Chlorine and residual chlorine in tap water could strip your hair and skin of  protein due to chemical reaction. Chemical changes affect colour, oils covering hair and proteins that form the hair shafts. Chlorinated water is also the cause of  dry and flakey skin. The outer protective layer of your skin and scalp contains a network of keratins and protein that help keep your skin hydrated. Contact with chlorine leaves the skin dry. To prevent this from happening, use a water purifying shower.  A sample is sold here. 

Feeding Baby

Do not use tap water directly into baby feeding bottles.  An adult’s immunity level being different from that of an infant, even just a small amount of liquid ingested by baby, matters.


About Ted Tanaka


  1. Mona

    November 23, 2017 at 11:27 pm

    Does japanese tap water contain sulphur?

  2. TF Tribe

    April 9, 2017 at 9:35 am

    Your comments are important to us. We’ve asked the author to update the article and cite the sources. We ask you to please have another look.

    • L

      April 11, 2017 at 7:27 pm

      it’s good that the author has cited sources on the updated version of this article, but their main source is a study from almost 20 years ago. Moreover, within the study there were large gaps of missing information for most or all of the European continent–as well as Japan. The biggest issue with the study is that it has nothing to do with the rest of this article. There is no reason to include the status potable tap water in the whole world; this article is supposed to be about tap water in Japan. What would be useful to know is if the Fukushima Power Plant leaks had affected the drinking water in Japan.

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