Water quality test results

In order to confirm the safety of tap water, Yokohama City inspects whether the 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 inspections at inspection points established by Yokohama City.
For details on the water test results of water taps (faucet), 15 water sampling points and daily inspection results are divided into Excel workbook sheets.
For details on the water quality test results at the water purification plant, the raw water and purified water from the 3 water purification plants are divided into Excel workbook sheets.
However, past results before FY2020 are posted separately on Excel workbook sheets for each water sampling month.

From fiscal 2022, water taps (faucet) will publish the water quality test results for the water purification plant in May, August, November, and February.

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

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