Engineering Newsletter

In 2006 alone, more than eight billion gallons of bottled water were sold in America, so it is hard to comprehend that there was a time when ranchers in the Southwest fought over water and residents of the Bronx had to leave their homes because of a “water famine.” Those problems were caused by an increase in population, a factor that has also caused recent water scarcity in North Carolina, South Carolina and Georgia, as well as in areas of the Southwest and West. Even as population changes impact water availability, climate change looms as a threat to the water cycle as we know it.

“Basic science defines the nature of the problem, but it is the work of applied scientists and engineers that will make changes and provide solutions,” says Peter Schlosser, Vinton Professor of Earth and Environmental Engineering in SEAS, professor in the Department of Earth and Environmental Sciences and associate director (and director of research) at Columbia’s Earth Institute. “What we are facing is far more explosive than any financial crisis,” he says, “but it is slow in pace—the environmental threats have been emerging for decades—and society and our political system readily respond to the crisis of the moment.”

But there is hope that institutions such as Columbia will bring to bear the intellectual brain-power of its faculty to find ways of ameliorating a deteriorating situation. For more than a decade, SEAS has taken the lead in bringing cross-disciplinary and trans-disciplinary expertise to tackle problems of water, air and climate change. Ranging from the disciplines of earth and environmental engineering to industrial engineering and operations research, SEAS faculty experts focus their research on these intractable, and interrelated, problems.

The recently created Columbia Water Center, a research unit of the Earth Institute, is directed by Upmanu Lall, Alan and Carol Silberstein Professor of Engineering in the Department of Earth and Environmental Engineering. It is the focal point for all water-related research at Columbia and draws on the expertise of faculty in several SEAS departments. It examines the problems of both water quantity and water quality. Water scarcity is being addressed by Lall, Vijay Modi, a professor in the Department of Mechanical Engineering, and Tim Huh, an assistant professor of Industrial Engineering/Operations Research. Water quality issues are being studied by Schlosser, Professor Patricia Culligan, in the Department of Civil Engineering and Engineering Mechanics, and Ponisseril Somasundaran, LaVon Duddleson Krumb Professor of Mineral Engineering, Assistant Professor Kartik Chandran and Assistant Professor Gavin Gong in the Department of Earth and Environmental Engineering. Other Columbia scientists, applied scientists, behavioral scientists and engineers are also involved.

$60 Million PepsiCo Grant
The Columbia Water Center recently received a $6 million grant from the PepsiCo Foundation to research and develop water sustainability initiatives in four countries facing a potentially acute water crisis— India, Mali, Brazil and China. Lall is leading a team that will focus on bottom-up strategies engaging communities, governments and the private sector, and emphasizing the role of market forces and public- private partnerships.

“This grant is allowing us to seed a revolution to meet global water needs,” says Lall. “There is not a universal solution to meeting water developandment and management challenges around the world. It depends on the area’s stage of development. We are using our knowledge of climate prediction, remote sensing, hydrology, market economics agricultural technologies together to innovate new business models for reliable local water supplies and responsible water use for these areas.”

“Climate change and changes in supply and demand make it possible to run out of water,” says Lall. “At some point, water stress will be worldwide. Global water sustainability is key to food security and the health of all living beings on the planet.”

For the countries covered by the PepsiCo grant, researchers will study different approaches to mitigating problems of water scarcity by focusing on technical innovations, such as drip irrigation, as well as policy measures such as the elimination of perverse subsidies and price supports. “We hope to provide a way for people to work with the water they already have by increasing and stabilizing farmer income, introducing water- saving crops, and exploring the use of new technologies of climate forecasting and irrigation,” says Lall.

The focus of mechanical engineering professor Vijay Modi is on two United Nations-designated Millennium Villages in sub-Saharan Africa. The villages of Tiby and Tombouctou (also called Timbuktu) in Mali are located in one of the poorest areas in the country and agricultural yield is dependent upon rainfall. The goal there is to increase crop yield and sustainability by determining the best crops to grow, not only for subsistence but also for outside markets, and by developing appropriate irrigation technology for the area.

“Unlike India, Mali is in the very, very early stages of development of water resources and it is more a question of how to get the supply there. We hope to encourage a system of agriculture that is sustainable right from the start,” says Modi. Mali has a system of river-fed streams that flood and recede during the year.

“Irrigation is essential for crop growth and there is a need for pumps to push the water. There is also a need for a water management system of canals to convey the water, and pumps to lift the water into storage tanks for later use. There is a need to increase irrigated land and provide more efficient use of equipment. The biggest entry point is fuel cost. By developing an infrastructure, Mali will be able to make better use of the water it has, which will ultimately result in an increase in the food supply.”

At a recent seminar addressing sustainable development for global water needs, Lall talked about the convergence of public and private investment to help provide solutions to local water problems. “A novel aspect of our work focuses on an involvement of the private sector into crop diversification and technology access into agriculture that will improve both the economics of agriculture and water use through contract farming, input provision and insurance mechanisms,” he said.

Assistant Professor Tim Huh of the Department of Industrial Engineering and Operations Research spoke about agricultural supply chain economics. “ Governmental concern is food safety, poverty and environmental sustainability,” said Huh. “ Private corporations, through contract farming, can influence the bottom line.”

By encouraging farmers to grow crops that use less water and by putting a factory next to farmland, profits are maximized. Contract farming guarantees prices and provides access to capital while insuring better use of water, he said.

Water Quality
Peter Schlosser’s research deals with the natural water system and how it is impacted by human action. One area of his work concentrates on the oceans, looking at water circulation, how the associated heat transport affects our climate and the role of the oceans in climate change. Closer to home, he and Doherty Associate Research Scientist David Ho, together with graduate students and summer interns, have collected basic information about water flow in and around New York, from the East and Hudson Rivers to New York Harbor, New York Bay, Arthur Kill, Kill van Kull and Newtown Creek, the only body of water the members of his group wore gloves to test.

From the vantage point of an icebreaker at the Arctic Circle, Schlosser sees the effect humans have had on the planet.

“The ice mass has depleted by one-third to 40 percent during the summer and, in 2007, there was a 20 percent drop in sea ice extent. We can’t be cavalier anymore because with more people on the planet, there is limited flexibility for each individual and global society to respond to the emerging environmental problems. The planet has a limit in carrying capacity,” he says, “but the science community is working to mitigate adverse effects such as greenhouse gas increase in the atmosphere and there are options we are exploring.”

Professor Patricia Culligan investigates ways to preserve the water quality in older cities like New York where the storm sewers and the sanitary sewers are combined. When rain storms overwhelm the storm sewers, raw sewage and storm water are jetted out into local water bodies such as the East River and the Hudson River.“ With global climate change,” she says,“ we can expect flooding rains to be more intense and more frequent.”

“One way to solve the problem is to create massive, and expensive, storm water detention basins at various locations around the City that can store storm water until it can be safely released for treatment,” she says, “but another alternative is a distributed system that can actually capture water and prevent it from being released into the combined sewer system. Green roofs have the capacity to retain certain amounts of rainfall and release it gradually.”

“ Green roofs are like sponges that retain water and then release it over time through outflow and evapotranspiration,” she said. Artificial substrates that are light enough to be supported on existing roofs have been commercially developed. At Columbia, several buildings have green roofs that provide a laboratory for Columbia researchers to study the behavior of different kinds and thicknesses of substrates and the behavior of different plants.

Model roofs on Pupin have 4-inch substrates while roofs on two other Columbia buildings have a 1-inch substrate. Doherty Research Scientist Wade McGillis, Stuart Gaffin of the Earth Institute’s Center for Climate Systems Research, Richard Plunz of the Graduate School of Architecture, Planning and Preservation and Assistant Professor Brian Mailloux of Barnard College also are working on this green roof research project.

“It is not always a shortage of water, but a shortage of potable water,” says Culligan, who works with other Columbia scientists and engineers to monitor the water quality of green roof run- off as well as the impact they have on air quality, carbon dioxide, building insulation and urban heat island management.

Toxic Water
Ponisseril Somasundaran, Krumb Professor of Mineral Engineering in the Department of Earth and Environmental Engineering, is part of a group of researchers developing low cost, low maintenance water purification systems to remove or deactivate toxic concentrations of arsenic, nitrates, sulphates and fluorine and to recover water from millions of gallons of waste sludges impounded in ponds and lakes.

“More than one billion people across the developing world cannot get clean and safe drinking water,” says Somasundaran. “There is no quantity without quality. Not a drop can be consumed if it is toxic.”

His group is using a hybrid strategy combining microbe-assisted separation with locally available, inexpensive, inorganic adsorbent/filter media to simultaneously remove multiple contaminants from the drinking water.

Another earth and environmental engineering researcher working on water quality is Assistant Professor Kartik Chandran, whose work is in engineered wastewater treatment technologies that are enabled by environmental microbiology and biotechnology.

As director of the Columbia University Biomolecular Environmental Sciences (CUBES) program, he is working to create environmentally sustainable wastewater treatment. Working with the Water Environment Research Foundation and Technical
University-Delft in the Netherlands, where he is currently located, Chandran is working to reduce the release of environmentally hazardous nitrogen-based gases when biological nitrogen removal (BNR) processes are used in wastewater treatment plants.

“Our studies show that use of BNR could be a significant contributor to atmospheric nitrous oxide and nitric oxide. This can create a major public health hazard since the greenhouse impact of nitrous oxide is 300 times that of carbon dioxide,” he says.

Gavin Gong, an assistant professor in the Department of Earth and Environmental Engineering, is another SEAS faculty member who brings a specialized and interdisciplinary approach to the Columbia Water Center. As a hydroclimatologist, he is interested primarily in the interaction between hydrologic and atmospheric phenomena, and their impact on climate variability and predictability.“ We analyze large environmental datasets, and conduct simulation experiments using sophisticated models of the Earth’s atmosphere and land surface water bodies,” he says.

His work focuses primarily on physical relationships between snow and climate, using statistical analyses and multi- dimensional climate models. He is also investigating alternative ways to identify the effects of climate variability and change on water availability in regions where the relationship is not well understood, such as right here in the northeastern U. S.

As research director of the Earth Institute, Schlosser appreciates the interconnectedness of the global issues that confront all of us on this planet. “Columbia has the breadth of approach that can bring together a diversity of disciplines to address problems of climate and society, water, energy, poverty, ecosystems, public health, food and nutrition, hazards and urbanization,” he says.“ It is the frontier and we are working to tame it.”