For the past 150 years, countries around the World have endeavoured to provide pure and wholesome drinking water for their population. The use of chlorine to disinfect water about 100 years ago led to a marked decrease in deaths from microbiological contamination. However, continual advances in industrial and agricultural processes has led to a continuing need to analyse water for chemicals and microbiologicals and assess their risk to health. This book reviews recent information on potential contamination of drinking water by chemicals, bacteria and viruses, their detection and risk assessment methodologies. It includes descriptions of contamination incidents and what can be learnt from them, and looks at the future of the global provision of pure and wholesome drinking water.