Introduction

Abstract

Today, a large share of the world’s population faces acute water scarcity. According to the World Bank, about 1 billion people do not have access to clean water (see World Bank, 2004, p. 1). Due to the ongoing growth of demand, water shortage will be an increasing problem in the near future. The World Commission on Water estimates that more than 4 billion people — half of the world’s population — will live under conditions of sever water stress by 2025. However, global raw water resources are not scarce. More than two third of the world’s surface consists of water. But 97 percent of this water is seawater and 2 percent is locked up in icecaps. As a result, only 1 percent of the world’s water is easy accessible drinking water. Nevertheless, from an economic perspective the entire water resources can be used, even seawater — it is a matter of treatment and transportation costs. Increasing the efficiency, respectively reducing the costs of water supply may be one of the major opportunities to solve the problem of global water scarcity. However, it is important to note that efficiency of water supply will not only be an issue in regions with acute water scarcity such as Africa, the Middle East and South Asia. Also developed regions such as Europe or Northern America face increasingly water resources challenges. One main issue is the increasing raw water pollution, which raises treatment effort and the related treatment costs. A further issue concerns dropping ground water tables. Many of the world’s major groundwater aquifers are threatened or already permanently damaged by salinization. Using alternative raw water resources as for instance surface water would raise treatment costs significantly.