The Water Research Institute at the Technion (Israel Institute of Technology) is proud to have initiated and sponsored the International Workshop "Soil and Aquifer Pollution: Non-Aqueous Phase Liquids - Contamination and Recla- tion," held May 13th-15th, 1996, on the Technion campus in Haifa. Groundwater contamination is one of the pressing issues facing Israel and other countries which depend on groundwater for water supply. In Israel, 60% of the water supply comes from groundwater, most of it from two large aquifers. The Coastal Aquifer underlies the area where the largest concentration of human activity already takes place, and where much of future development is expected to occur. It is a phreatic sandstone aquifer, vulnerable to pollution from activities at the surface. The Mountain Aquifer is recharged in the higher terrain to the east, and flows, first in a phreatic zone, then confined, westward and underneath the Coastal Aquifer. This limestone aquifer has higher permeabilities and flow velo- ties, so pollution can reach the groundwater quite readily. Smaller local aquifers are also important components in the national water system. While measures are taken to protect these aquifers from pollution, there are locations where contamination has already occurred. Furthermore, accidental pollution may not be totally avoided in the future. Therefore, understanding the processes of groundwater contamination, recommending the proper measures for preventing it, and determining the best means for reclamation once pollution has occurred, are of great practical importance. Non-aqueous phase liquids (NAPLs) are among the most significant contaminants.

Water is vital for the life and health of people and ecosystems, and is a basic condition for the development of countries. Water resources, and the related ecosystems which are sustained by water, are under threat from pollution, unsustainable use, land-use changes, climate changes and many other forces. This book incorporates basic and advanced information on all topics and issues relevant to the preservation of water resources quality. Its main strength lies in covering all aspects of water quality preservation, including: engineering hydrology, environmental and chemical aspects, quantitative (modeling approaches) and qualitative issues.

Environmental Fluid Mechanics provides comprehensive coverage of a combination of basic fluid principles and their application in a number of different situations-exploring fluid motions on the earth's surface, underground, and in oceans-detailing the use of physical and numerical models and modern computational approaches for the analysis of environmental processes. Environmental Fluid Mechanics covers novel scaling methods for a variety of environmental issues; equations of motion for boundary layers; hydraulic characteristics of open channel flow; surface and internal wave theory; the advection diffusion equation; sediment and associated contaminant transport in lakes and streams; mixed layer modeling in lakes; remediation; transport processes at the air/water interface; and more.

Environmental Fluid Mechanics provides comprehensive coverage of a combination of basic fluid principles and their application in a number of different situations-exploring fluid motions on the earth's surface, underground, and in oceans-detailing the use of physical and numerical models and modern computational approaches for the analysis of environmental processes. Environmental Fluid Mechanics covers novel scaling methods for a variety of environmental issues; equations of motion for boundary layers; hydraulic characteristics of open channel flow; surface and internal wave theory; the advection diffusion equation; sediment and associated contaminant transport in lakes and streams; mixed layer modeling in lakes; remediation; transport processes at the air/water interface; and more.

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.

The Water Research Institute at the Technion (Israel Institute of Technology) is proud to have initiated and sponsored the International Workshop "Soil and Aquifer Pollution: Non-Aqueous Phase Liquids - Contamination and Recla- tion," held May 13th-15th, 1996, on the Technion campus in Haifa. Groundwater contamination is one of the pressing issues facing Israel and other countries which depend on groundwater for water supply. In Israel, 60% of the water supply comes from groundwater, most of it from two large aquifers. The Coastal Aquifer underlies the area where the largest concentration of human activity already takes place, and where much of future development is expected to occur. It is a phreatic sandstone aquifer, vulnerable to pollution from activities at the surface. The Mountain Aquifer is recharged in the higher terrain to the east, and flows, first in a phreatic zone, then confined, westward and underneath the Coastal Aquifer. This limestone aquifer has higher permeabilities and flow velo- ties, so pollution can reach the groundwater quite readily. Smaller local aquifers are also important components in the national water system. While measures are taken to protect these aquifers from pollution, there are locations where contamination has already occurred. Furthermore, accidental pollution may not be totally avoided in the future. Therefore, understanding the processes of groundwater contamination, recommending the proper measures for preventing it, and determining the best means for reclamation once pollution has occurred, are of great practical importance. Non-aqueous phase liquids (NAPLs) are among the most significant contaminants.