With over 90,000 workers in the water environment industry and technological developments rapidly advancing understanding in this area, water has become one of the most important issues of our time. Career scope for those working in the water and wastewater engineering sphere is expanding. This accessible student textbook introduces the reader to the key concepts of water technology by explaining the fundamentals of hydrobiology, aquatic ecosystems, water treatment and supply and wastewater treatment. The Water Framework Directive is the driving force in European water management and protection. Professor Gray uses the Water Framework Directive as the unifying theme of this new edition. This text provides a complete introduction to all aspects of managing the hydrological cycle and is ideal for those interested in a career in the water industry.For masters' students in evironmental science, engineering and construction courses and those in the CIWEM diploma, Water Technology, 3e, is an essential resource that will continue to be useful in professional life.