Water quality measurement data

At 11 water reclamation centers in the city, we conduct water quality tests of sewage flowing into the water reclamation center and water discharged into rivers and sea areas. In particular, the water discharged from the Water Reclamation Center has emission standards, and it is confirmed that the treatment that meets the standards has been confirmed.
This section makes an annual water quality test report that summarizes the water quality test results every year.

The annual water quality test reports for FY2004 and for FY1970, FY55, FY1990, FY7, and FY12 have been released.
Please contact us for other annual reports.

Annual water quality test report

Maps are color-coded for each water reclamation center treatment zone.

In addition to introducing the role of sewerage in the water environment and the mechanism for cleaning dirty water, it also explains clearly how dirty water can be revived using sewage water quality data.

• Sewer of Yokohama in terms of water quality (issued in August 2024) (PDF: 16,689KB)
• English Version(2016)（PDF：3,929KB）

In addition to introducing the role of sewerage in the water environment and the mechanism for cleaning dirty water, it also explains clearly how dirty water can be revived using sewage water quality data.

Sewer Q & A of Yokohama in terms of water quality (2016 version) (PDF: 1,597KB)

We publish summary of investigation, research about sewer which this section (including former affiliation name) announced so far in national sewer research presentation, staff duties presentation in bureau. (Unauthorized reproduction and secondary use of the published abstracts are prohibited.)

Summary of Survey and Research