It is difficult to imagine anything more important to the human population than safe drinking water. Lack of clean drinking water is still the major cause of illness and death in young children in developing countries. In more fortunate communities, where water treatment is practiced, the primary aim of water authorities is to provide water that is free from pathogens and toxins. Most countries now have water quality regulations, or guidelines, which are driving water authorities to produce purer water, with the minimum of contamination from natural or man-made origin. At the same time,...