EVALUATION OF WATER SUPPLY UTILITIES FOCUSING ON WATER QUALITY AND WATER TREATMENT

Abstract

 Tap water system in Japan is now in management stage rather than new construction. In this study, we focus on the problem that many waterworks are small in scale and have a weak management base, and analyze the characteristics of waterworks nationwide by type of water source and population size. We used the water supply statistics of the Japan Water Works Association to analyze the use of chemicals such as sodium hypochlorite and polyaluminum chloride, which are related to water quality. A comparison was made based on selected indicators such as water supply revenue (net), the number of technical staff per annual water intake, and relevant water quality items. As a result, it was found that, water supply revenue (net) and the number of technical staff tended to be higher in utilities with excessive chemical injection volume, and that utilities with excessive chemical use may not be operating chemicals efficiently.