Ever since the recognition of the important role of water in the transmission of pathogenic micro-organisms in the 19th century, microbiological safety of drinking water has been a major research issue for microbiologists in the drinking water industry.The main objective of this book is to develop a general strategy to assess elimination capacity of water treatment processes for pathogens. It investigates: * The potential use of faecal indicators Coli44, (including E. Coli) and SSRC, (including C. perfringens) as process indicators to assess pathogen elimination in full-scale water treatment plants. * The value of comparative challenge tests with pre-cultured organisms for the assessment of elimination capacity of full-scale processes, to study the effect of process conditions and to validate the use of process indicators. * The use of literature data to assess elimination capacity of water treatment processes for pathogens and the effect of process conditions on this.