Isesaki City, Gunma Prefecture announced on the 16th that hazardous substances exceeding standard values were confirmed in factory wastewater flowing into the Kuruma River, a tributary of the Hirose River.
Although wastewater from the factory has already stopped, Isesaki City and other authorities are asking people not to enter the surrounding rivers until detailed investigation results are known.
According to Isesaki City, on the 14th, the city investigated the wastewater from a factory in Shiba-cho, Isesaki City that discharges water into the Kuruma River, a tributary of the Hirose River, and found that it contained hazardous substances such as dichloromethane and trichloroethylene that exceeded standard values. This means that the substance has been confirmed.
Of these, dichloromethane was found to have a concentration 3,500 times higher than the standard value in factory wastewater.
In response to an interview with the city, the factory explained that dichloromethane was used for business purposes and that there was a problem with the sewage treatment equipment.
As of now, there is no information on damage.
Although drainage from the factory has already been stopped, the city has warned that it may affect water intake downstream, and is asking people not to enter nearby rivers until the results of a detailed investigation are known.