LESSONS IN RIVER MANAGEMENT OBTAINED FROM THE CORRESPONDING TO THE RIVER WATER QUALITY ACCIDENTS BY FORMALDEHYDE ON TONE RIVER SYSTEM AND SUBSEQUENT EFFORTS

Abstract

Conservation of water quality of rivers in Japan is an important national measure to support the life of the people and industry. However, concerns about ensuring the water quality preservation of the river have occurred.

In recent years, one of the cases that give a major social impact has been concern is a water quality accident caused by formaldehyde in the Tone River system that occurred in May 2012. This water quality accident resulted in widespread damage in the basin. Chemicals that caused the water quality accident were generated by the chemical reaction between the disinfectant chlorine introduced in a water purification plant and the precursors contained in the raw water taken from the river. Since the number of similar past accident examples in Japan is less, in order to contribute to the future river water quality accident measures, the authors introduce the new approach and the lessons that river administrator learned from the accident.