Water is a paramount determinant of quality of life. The WHO experts believe that the sickness and death rates of the world population could be reduced by 75 % by maintaining good quality of drinking water. That is why thirty-one leading scientists and specialists from fifteen countries gathered in November 2003 at the NATO Advanced Research Workshop (ARW) on 'Modem Tools and Methods of Water Treatment for Improving Living Standards' in Dnepropetrovsk, Ukraine, to discuss the scientific concepts and practical means for the solution of the complex social, economic and ecological problems associated with water purification, consumption, conservation, and protection. All this is covered in this book of proceedings of the NATO ARW. This book contains four parts. In Part 1 , the readers could find recent advances in drinking water treatment in the United States, biological control in water-cooling towers, analytical control of drinking water quality, and the use of radionuclides for monitoring global contamination. In Part 2, some innovative methods and tools, such as electrochemically-stimulated sorption and sorption-membrane methods, a bubble- extraction method, fibroid sorbents, in-situ oxygen curtain technology, use of ion- exchange membranes, electrochemically-generated silver and copper ions and colloidal gold for water purification and post-purification are presented. In Part 3, recent studies into the treatment of wastewaters could be found. Among them: water reclamation and recycling in Danish industry, biocide polymers as a new opportunity in water treatment, optimization of galvanic wastewater treatment processes, efficiency of nitrification and denitrification processes in wastewater treatment plants, electrochemical processes for wastewater purification employing fluidized beds of particles, cold plasma as a new tool for purification of wastewater from chemical contaminants, bacteria and viruses. In Part 4, examples of management of water resources inthe United Kingdom, Bulgaria, Poland, Croatia, and Romania using a variety of case studies are presented. Also, the important issue of industry-university cooperation for postgraduate education and training in the water treatment area is discussed. We believe that this book will be helpful to the international community of scientists, specialists and students dealing with water treatment, purification, conservation and protection.