Data, measured at the water source, on the quality of water is essential for both the delivery of services and the prevention of diseases. In order to satisfy the minimum requirements for this category, data should be available on level of the following chemicals by water source and be updated at least weekly:

  • fecal coliform
  • arsenic
  • fluoride levels
  • nitrates
  • TDS (Total dissolved solids)

Data Location


Water Quality data is available on this page. Yearly published.

Comparizon with minimum requirement and this dataset.

  • fecal coliform 大腸菌 < OK
  • arsenic ヒ素 < OK
  • fluoride levels フッ素 < OK
  • nitrates 硝酸 < OK
  • TDS (Total dissolved solids) 総溶解固形分 < Not available

Also, each prefectures publish their own inspects from their web page. Some of those data are available monthly/yearly, not Open.

Reviewer comments

The reason I changed the answer to Yes the data exists. Is because the government is collecting it as referenced by the Ministry of Health It is their responsibility to monitor it.

However, water quality data itself is in the hands of the municipal and local utilities. So yes the data exists, is being collected by government, is send to the central ministry for reports, but the real time useful data is not at the national level.

I.e Tokyo's water quality data -

Data Availability

  • N Openly licensed
  • ? Is the data available for free
  • N Is the data machine readable
  • N Available in bulk
  • N Is the data provided on a timely and up to date basis
  • Y Is data in digital form
  • N Publicly available
  • Y Does the data exist
  • N Is the data available online
  • Yes
  • No
  • Unsure
  • No data


Date the data became available   Unknown
Format of data   Unknown
Reviewer   Nisha Thompson
Submitters   Satoshi IIDA
Last modified   Sun Sep 27 2015 06:09:52 GMT+0000 (UTC)