“Environmental Microbiology” is the study of the composition and physiology of microbial communities in the environment. Microbial life is amazingly diverse and microorganisms literally cover the planet. One of the major prerequisites for a healthy life is an adequate supply of safe drinking water. Waterborne diseases are still a major cause of death in many parts of the world, particularly in young children, the elderly, or those with compromised immune systems. As the epidemiology of waterborne diseases is changing, there is a growing global public health concern about new and reemerging infectious diseases that are occurring through a complex interaction of social, economic, evolutionary, and ecological factors. An important challenge is therefore the rapid, specific and sensitive detection of waterborne pathogens. Presently, microbial tests are based essentially on time-consuming culture methods. However, newer enzymatic, immunological and genetic methods are being developed to replace and/or support classical approaches to microbial detection. Moreover, innovations in nanotechnology and nanosciences are having a significant impact in biodiagnostics, where a number of nanoparticle-based assays and nanodevices have been introduced for biomolecular detection. Molecular techniques based on genomics, proteomics and transcriptomics are rapidly growing as complete microbial genome sequences are becoming available, and advances are made in sequencing technology, analytical biochemistry, microfluidics and data analysis. While the clinical and food industries are increasingly adapting these techniques, there appear to be major challenges in detecting health-related microbes in source and treated drinking waters. This is due in part to the low density of pathogens in water, necessitating significant processing of large volume samples. From the vast panorama of available molecular techniques, some are finding a place in the water industry: Quantitative PCR, protein detection and immunological approaches, loop-mediated isothermal amplification (LAMP), microarrays. This book gives a detailed insight related to all these aspects. The book is divided into 12 chapters. In the first chapter, the authors has discussed in detail about various molecular methods for the detection of microbes in source and drinking water. In second chapter, various advancements in methods used earlier have been given for microbial concentration by reducing the volume of water samples. Third chapter deals with the detection of water borne pathogens by using antibodies and gene-based recognition chemistries as biosensors. In fourth chapter, details regarding screening of multiple waterborne pathogens are given based on low cost technology of loop-mediated isothermal amplification (LAMP), a relatively new DNA amplification technique. In fifth chapter, the authors have stressed the use of microarray technique, whereby, the detection of multiple genetic sequences from different viruses, bacteria, protozoa, and other emerging pathogens is possible. This is advantageous and eliminates all the hurdles faced with earlier techniques. In sixth chapter, the authors have highlighted in detail the general approaches for the growth of overlooked obligate intracellular microorganisms using amoebae as a host. Alternative approach for the isolation of new/novel potentially pathogenic amoeba-resisting microorganisms (ARM) is also described. Chapter seven describes the combination of Raman spectroscopy with Fluorescence in situ Hybridization (FISH) and Stable Isotope Probing (SIP) to gather information about heterogeneity within populations and the role of spatial organization within the environment. In chapter eight, details regarding the detection of viability of organisms and the functional gene expression by using various molecular techniques are given. In chapter nine, the authors have stressed the use of GS-FLX pyrosequencer, a next generation sequencing approach for characterization of microbial community structures in recreational waters and primary sources of faecal pollution. In chapter 10, the author has emphasized the monitoring of faecal pollution by microbial indicators rather than by direct pathogen detection with its advantages. Details regarding use of molecular methods to track faecal sources of pollution in environmental waters are also given. Chapter 11 gives an insight of the various microarrays available for environmental analysis with special reference to the use of Geochips, a powerful tool for rapid, sensitive and specific examination of microbial communities in a high-throughput manner. In chapter 12, the authors have discussed the use of microbes as microbial bioreporter, for its use in detecting chemicals or bacterial pathogens. Their possible use as a biosensor for rapid and versatile water quality monitoring tool is also discussed. This book this focuses on the current and future technologies as well as its applications related to environment with special reference to water microbiology. It will be of immense help to water and environmental microbiologists as well as regulators and is recommended for all life science professionals and scientists.