Abstract
The way that the global sustainability and the systems of water supply and the sewage works in the 21st century should be discussed. In principle recycle of material resources is possible, while energy recycling is impossible. The development of technology for utilization of energy and resources and the formation of new life style insuring energy saving and resources recycling are indispensable for the formation of our global sustainability. In considering the elevation of life style of developing countries, however, the achievement of that aim still difficult. In the 21st century, the establishment of a new water supply and sewage system should be promoted. The author proposed the effective supply of drinking water of a small quantity and washing water of a large quantity as a countermeasure for serious water resources pollution, and also the re-establishment of a sewage system with a strong concept that does not produce polluted water as much as possible.
