In the latest revision in 2004, the 3rd edition, the Water Safety Plans (WSP) was newly introduced into the World Health Organization (WHO) Guidelines for Drinking Water Quality. The Hazard analysis and critical control point (HACCP) is a basic concept that underlies the WSPs, and is also known as the product quality management method in the field of food and the medical manufacturing industries. In the amendments of the Drinking Water Quality Standards in Japan, water suppliers are required to reasonably achieve both safe water and efficient water quality management. Therefore, the HACCP concept is focused as an adequate management method covering a whole process of water supply systems, in a systematic way.
The purpose of this study is to investigate a practical procedure in introducing the HACCP into water quality management in Japan. In comparison to conventional applications of the HACCP, unmanageable variations of raw water quality, continuous treatment and supply, and numerous standards of water quality items need to be considered. The HACCP system is expected to achieve a quick response to improvements in water quality, accountability towards consumers and a decrease in accidents.