The definitive student text in its field for 25 years, this new edition takes an environmental perspective that is highly relevant in the context of current public policy debates. New material also includes EU regulations and changes in the UK water industry since privatisation. The latest technological developments are also taken into account. As before, the book is intended for undergraduate courses in civil engineering and the environmental sciences, and as preliminary reading for postgraduate courses in public health engineering and water resources technology. It will also be a vital text for post-experience training and professional development, in particular for students preparing for the examinations of the Institute of Water Pollution Control and the Institution of Public Health Engineers.