Using recycled water for non-potable, urban uses: a review with particular reference to toilet flushing

This paper summarises the current non-potable, urban use of reclaimed water with particular reference to toilet flushing. It compares water quality standards for reclaimed water, the volumes of water required for toilet flushing and the qualities of greywater and domestic sewage that have previously been used for reuse. Worldwide examples of reuse schemes are presented with particular detail to two key European sites where greywater has been used for toilet flushing, the Millennium Dome in the UK and a residential block of flats in Annecy, France. It was demonstrated that the interest in water reuse is growing steadily, not only in acknowledged water deficient areas, but also in countries which have not historically appeared to have a water supply problem. The latter include Northern European States such as Belgium, France, the UK and Germany, as well as in tourist coastal areas and islands. This situation affords great opportunities for the creation of urban water recycling schemes.