Case Studies

Nihonbashi River, which separates from the Kanda River near JR Suidobashi station, is a first-grade river of 4.8km in length that flows into the Sumida River. The river was dug in the early Edo period, and the river was the main line of logistics to support the city of Edo. After World War II, although people still could swim in the river, during the period of high economic growth it steadily grew polluted. Further, after it was covered by a highway, it became less a part of people's daily lives. The original starting point of Japan's road system, the landscape of "Nihonbashi" is severely hampered by the highway. People are proceeding with a plan to recover the blue sky over Nihonbashi by dismantling the overpass.

 

The Background of the Nihonbashi River water system improvement project using EM

Hoping that, when the blue sky returned to Nihonbashi, the Nihonbashi River would be once again be a clear-running-river, people began their efforts to improve the water system under the slogan “Revive the Nihonbashi River!” By then, the use of EM had been successful in cleaning the Asechi River, and organizations such as the Historic Bridge "Nihohnbashi" Preservation Society and the not for profit organization Bring Back Clean Water in Nihonbashi River・Kanda River, have implemented this activity utilizing EM along the Nihonbashi River with the cooperation of companies and civil organizations.
 

In July 2005, they threw 3,000 EM Mudballs into the river in a project to clean the Nihonbashi River. Since then, they have regularly introduced EM Mudballs into the river. In December 2006, a plant that manufactures EM was completed in Nishi-Kanda in Chiyoda-ku. 

The plant has the capacity to culture 10tons of Activated EM and, since then, they have been applying 10 tons of Activated EM every week. Furthermore, since the water of the Imperial Palace outer moat overflows into the Nihonbashi River, the groups began applying Activated EM and EM Mudballs to the Ushigome moat near JR Iidabashi Station from July 2007, and they are continuing this activity now. The total amount of Activated EM and EM Mudballs which have been used in the Nihonbashi River and Ushigome Moat so far is shown below. 

Supporting partnership

In June 2006, three organizations: the Historic Bridge "Nihonbashi" Preservation Society, the Nihonbashi Corporation Association and the Nihonbashi Rotary Club decided to implement a project to clean up Nihonbashi River with technical support from U-net (United Networks for Earth Environment, NPO), and looked for a location to install Activated EM production equipment.

Chiyoda-ku decided to rent a place where the 20 town councils and corporate wards founded the "Revive Clean Water in Nihonbashi River and Kanda River Group". Here, they started the construction of an Activated EM production facility in September 2006, and was completed in December of the same year.

Changes in biodiversity recovery of Nihonbashi River

Although there were originally a variety of living things in the Nihonbashi River, since most of the water source is sewage treatment water, the water quality is not stable, depending on the weather, the opportunity of encountering living creatures was rare. In the wake of applying EM to the Nihonbashi River, we began our own study of the river, which is still ongoing. According to this study, we found that the frequency of encountering living creatures in the Nihonbashi River has increased, and that the variety has also grown.

Continue reading how this proyect changed the area.