It's at the top of this page.

Water quality test results

Final update date April 19, 2021

About water quality inspection

Water quality inspections have confirmed that tap water delivered to customers conforms to the water quality standards of the Water Supply Law. In Yokohama City, we conduct water quality tests not only at water taps (faucets) that are required as places for water quality inspections, but also at entrances and water sources at water purification plants.

Water quality test results

Monthly water taps and water quality test results at water purification plants are divided into Excel workbook sheets.
The number (frequency) of inspections differs for each inspection location and item. Please refer to the water quality inspection plan for details on the location, items, number of inspections, etc. of the water quality inspection.
Please refer to here for commentary on 51 water quality standards.

Water tap (faucet)

Water Purification Plant

For inquiries about water supply, please contact Water Works Bureau Customer Service Center.

Water Works Bureau Customer Service Center

Telephone: 045-847-6262 Fax: 045-848-4281
※Please be careful not to make a mistake.

Inquiries to this page

Water Works Bureau Water Purification Department Water Quality Division

Telephone: 045-37-5656

Telephone: 045-37-5656

Fax: 045-37-6942

Email address: [email protected]

Return to the previous page

Page ID: 833-439-187

return to the top