Non-waterborne Sanitation and Water Conservation

Conventional urban water and wastewater systems owe their design in particular to 19 Century thinking on combating waterborne disease and maintaining hygienic conditions in cities. The success of these systems has been out-lived and they are no longer compatible with closed systems which seek to minimise the net use of resources, encourage local recycling, water conservation and source protection as demanded by the requirements of a sustainable city. In spite of the efforts during UNESCO's International Decade 1981-1990 still 1.2 billion of the world's population lacks access to safe drinking water and about 3 billion lacks adequate sanitation. Conventional sanitation in the form of flush-and-discharge has offered limited solution to this global sanitation crisis suggesting that the flush toilets are slowly becoming obsolete. There is therefore a need for a fundamental rethinking of the problem, a new approach, a new paradigm? Urban water and wastewater systems design have almost gone a full circle within this era.