Results of water quality inspection

In order to confirm the safety of tap water, Yokohama City checks whether tap water delivered to customers conforms to the water quality standards of the Water Supply Law.

We confirm the safety of tap water quality by conducting water quality tests at inspection points established by Yokohama City.
For details of the water quality test results of the hydrant (faucet), 15 sampling points and daily test results are divided into sheets in Excel workbooks.
For details of the water quality inspection results of the water purification plant, the raw water and purified water of the 3 water purification plants are divided into sheets in Excel workbooks.
However, past results before 2020 are separately posted on Excel workbook sheets for each water sampling month.

From 2022, hydrants (faucets) will publish the water quality inspection results for May, August, November and February at the water purification plant.

Please refer to the water quality inspection point for the water sampling point of the nearby hydrant and the water distribution area of the water purification plant.
Please refer to the water quality inspection plan for details such as water quality inspection items and number of inspections.
Please refer to the water quality inspection items for explanations of 51 water quality standards.

Results for this fiscal year and the past five years are posted.