Abstract
Formaldehyde was detected in the purified water of some purification plants in the Tone river system in May 2012.Some water utilities suspended water supply and 870,000 people was affected. Also, the water quality accident raised many issues regarding crisis management of drinking water quality because it had specificity of the causative substance, hexamethylenetetramine. Hexamethylenetetramine is high hydrophilic, so it cannot be reduced by powdered activated carbon. Without odor, color and high toxicity, it is difficult to find the substance at the river. And the most unique point is that it is formaldehyde precursor. By dealing with the issues, the tap water quality management can be improved further more.
