In This Issue
Technologies for Clean Water
September 1, 2008 Volume 38 Issue 3
The Bridge, Volume 38, Number 2 - Fall 2008. The papers in this issue of The Bridge describe some recent advances in the search for water, in the distribution and treatment of water and wastewater, and in the modeling of complex water systems.

Water: Advances in the Supply and Management of a Vital Resource (Editorial)

Monday, September 1, 2008

Author: George Bugliarello

Editor’s Note

We cannot live without water, and our civilization would collapse without it. But water can also destroy us and our way of life, because, since neolithic times, people have tended to settle near water—on deltas, near rivers, and along coastlines. It has been estimated that some 70 percent of the world population today lives in areas at risk from floods, tsunamis, storm surges, and changes in sea level as a result of bradyseisms and the consequences of climate change. Thus we are confronted by the twin imperatives of (1) finding enough water to satisfy our needs and (2) defending ourselves against the threat of disasters caused by water.

As the global population continues to grow, the water we need is becoming increasingly scarce. Thus we must recycle water, search for new sources of water, use water more efficiently, and reduce losses in water distribution systems. Ironically, even though water is abundant, its availability and accessibility for drinking, agriculture, and industrial uses are limited and unevenly distributed geographically.

As human activity intensifies, water throughout the world is increasingly threatened by pollution, exposing large populations to noxious, toxic, waterborne substances and infections. Concentrations of humans in urban aggregates present a multiplicity of challenges: how to supply and distribute necessary water; how to treat water to make it potable; and how to manage rainwater and storm water. These are major engineering and societal challenges.

The papers in this issue of The Bridge describe some recent advances in the search for water, in the distribution and treatment of water and wastewater, and in the modeling of complex water systems. Addressing these problems will require that engineers work closely with social, ecological, legal, and financial experts and with all levels of government.

The balance between water supplies and population varies by continent and region. Hence the urgency in some areas, like the deserts of Egypt and the Sudan, to find new sources of fresh water, for example, by using geohydrological observations from satellites, as described in the article by Farouk El-Baz (NAE).

The paper co-authored by Abu Hussam (the first winner of the NAE Grainger Prize for Sustainability, sponsored by the Grainger Foundation), Sad Ahamed, and Abul Munir addresses the problem of the natural presence of arsenic in groundwater, which affects the populations of 35 countries. In the Ganges-Meghna-Brahmaputra basin alone, as many as 500 million people are at risk.

Pete Loucks (NAE) shows how models of complex water resources are being used in making decisions about water supplies in cities, the restoration of ecologically important areas, and water management in complex river systems.

Vanessa Speight describes problems in water-distribution systems. Even in communities with extensive water-treatment systems, the quality of the water that reaches customers may be different from the quality of the water at the treatment plant. She describes how the age and weaknesses of many water-distribution systems exacerbate health risks to urban populations.

Glen Daigger (NAE) stresses the need for closed-loop, energy-neutral water systems, which will require more reliance on local resources, better access to clean water and sanitation, and responsible management of nutrients in wastewater streams—all facets of the global quest for sustainability. New approaches and technologies, such as advanced monitoring and control systems, microbial fuel cells that can extract electric energy from organic matter, and nanotechnology that can improve the performance of water-separation membranes, are all in development.

The themes of the preceding papers are underscored by Jerry Schnoor (NAE), who also stresses water and land limitations and the economic reverberations of the development of biofuels. He advocates, as per a current proposal to the National Science Foundation, a substantial capital investment to revolutionize the modeling and forecasting of water quantity and quality. Problems related to water use and availability are a source of intense concern globally. Unless they are resolved, they will hamper social and economic development and accentuate disparities between water haves and have-nots and conflicts for the control and use of water among water-poor regions, as well as between cities and rural areas and among cities, regions, and nations. Unfortunately, water problems, for all of their urgency and importance, are just one of many infrastructural challenges facing the United States—and much of the world. Water problems add to their enormous magnitude and complexity.

About the Author:George Bugliarello is Foreign Secretary of the National Academy of Engineering and Interim Editor in Chief of The Bridge