This monograph results from the 4th International Austrian-Israeli Technion Symposium cum Industrial Forum under the banner of the Austrian Technion Society initiative Technology for Peace - Science for Mankind, which was held in Vienna, 23 - 25 April 200 I, devoted to Preservation of the Quality of our Water Resources. The Symposium was a cooperative effort with the Austrian Federal Ministry of Education and Science and Culture, and the Austrian Federal Ministry of Economy and Labor. The program was structured and managed by a joint Program Committee incorporating the editors of this monograph, who are faculty members from the Stephan and Nancy Grand Water Research Institute at the Technion - Israel Institute of Technology, and the University of Agricultural Sciences (Bodenkultur) of Vienna. The Symposium attracted participation from universities, research institutes, industries, and national authorities from Austria, Germany, Greece, Hungary, Israel, Jordan, Palestinian Autonomy, Poland, Russia, Spain, Turkey, USA, and Uzbekistan. The Symposium topics were of major international interest, and talks were at a high professional level. Therefore, I have gladly accepted the initiative of the Symposium Program Committee to extend and expand manuscripts of special merit to chapters of this monograph, whose title is identical to that of the Symposium. Out of the 39 papers presented at the Symposium, 24 papers were selected for inclusion in this monograph, according to their scientific merit and quality of contribution to the overall subject. Those selected were expanded and subjected to peer review for inclusion in this Volume.