Providing the population of the Earth with safe drinking water is one of the biggest challenges of modern society. In recognition of this problem the United Nations Organization and UNESCO declared 2003 to be the International Year of Freshwater. On November 19-22, 2003, the NATO Advanced Research Workshop (ARW) on "Modern Tools and Methods of Water Treatment for Improving Living Standards" took place in Dnepropetrovsk, Ukraine. Thirty-one participants from 15 countries including Bulgaria, Canada, Croatia, Czech Republic, Denmark, Italy, Lithuania, Moldova, Poland, Romania, Russia, UK, Ukraine, USA, and Uzbekistan attended the meeting. They discussed 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. They also established a network of scientists and specialists to foster further collaboration and the exchange of ideas. The location of the ARW was chosen quite deliberately. The city of Dnepropetrovsk is located on the banks of the Dnieper River and it has a population of about 1. 3 million people. As it is one of the largest industrial centers, it shares all the environmental problems, which are found in the modern Ukraine. In 2001, one in seven of the water samples taken from Ukrainian industrial and drinking water supply systems did not meet sanitary-hygienic standards, and one in twelve did not meet microbiological standards.