Stable, safe, secure and readily available water supply is one of the key factors in ensuring a good level of the public health and a stable society. Scientific assessments show that about 80 % of diseases and one-third of the total death toll in the developing countries are caused by the low quality of the drinking water. Other countries are also suffering from water shortages and insufficient quality of the drinking water. Many rivers in Europe and in other parts of the world are significantly polluted by insufficiently treated or untreated wastewater discharge. This book is based on the discussions and papers prepared for the NATO Advanced Research Workshop that took place in Lviv, Ukraine, and addressed recent advances in water supply and wastewater treatment as a prerequisite for a safer society and environment. The contributions critically assess the existing knowledge on urban water management and provide an overview of the current water management issues, especially in the countries in transition in Central and Eastern Europe and in the Mediterranean Dialogue countries.