Steven C. Chapra © Mark Morelli

Environmental engineers work to protect nation's watersheds
by Craig LeMoult

Tufts engineers have received two grants totaling more than $1.2 million from the U.S. Environmental Protection Agency to devise a way to control the destructive effects of excessive nutrients in waterways—an environmental problem that threatens aquatic plant and animal life nationwide.

"Tufts is a national leader in computer modeling for urban water quality issues," said Steven C. Chapra, the Louis Berger Professor of Civil and Environmental Engineering. "These grants will leverage our expertise in developing computer models that will reflect the ways in which nutrients—such as lawn fertilizer, animal waste and other substances—enter America's waterways."

The computer models developed by Chapra and a team of Tufts civil and environmental engineers, including Paul Kirshen, Richard Vogel, John Durant and Linfield Brown, will help scientists and communities across the country more effectively manage nutrients.

A phenomenon known as "eutrophication" occurs when these nutrients foster excessive plant growth in water, which, in turn, saps oxygen levels and kills aquatic life. The lack of oxygen also leads to the release of more nutrients and other pollutants from sediments into the water.

In recent years, the federal government has mandated that local governments adopt a new approach to managing water quality by focusing on all factors affecting a watershed (an area of land that encompasses smaller waterways that drain into a larger body of water), rather than simply regulating the most significant polluters. This new approach means that significant but often-overlooked factors such as street and agricultural runoff are now taken into account.

The digital modeling tools that the Tufts engineers are developing with colleagues from MIT and North Carolina State will help communities map out their watersheds, identify trouble spots and take cost-effective steps to manage the nutrients entering the water. The Tufts team also will develop similar computer models that will be used by the EPA and state governments to improve their current systems for managing watershed nutrients.

The engineers are using the Mystic and Aberjona watershed areas in Massachusetts to design the computer modeling programs. However, Kirshen said, "the technology we've developed will benefit waterways throughout the world."

The watersheds of the Aberjona and Mystic rivers are ideal for this research because they encompass urban, residential and pristine lands with streams and lakes. Many of these areas have been heavily affected by decades of development and contamination. A half-million Massachusetts residents—just under 10 percent of the state's population—live in 21 cities and towns within the 76 square-mile Mystic River watershed alone.

"For more than 30 years, Tufts' civil and environmental engineers and health sciences researchers have been trailblazers in addressing the safety and security of our world's most precious resource—water," said Jamshed Bharucha, Tufts' provost and senior vice president. "In the past five years alone, they have received more than $20 million in funding because of their leadership in tackling a wide range of water issues, from groundwater remediation and watershed pollution to water-borne bacteria and wildlife habitat preservation. And their findings continue to create and/or strengthen public policies regarding the proper use and protection of the world's water supply."

The Tufts team is also in the final stages of another EPA-funded project—developing the first system to predict, assess and report on the Mystic River's water quality to area residents in real time.

Tufts engineers have installed water monitoring equipment along the Mystic River and Alewife Brook at locations heavily used by recreational boaters and swimmers. This spring, data from these sites will be transmitted through radio technology to a central server at Tufts, where the information will be processed, archived and available to the public through dial-in phone messages, cable television and web sites. Color-coded "water quality" flags also will be placed at key riverfront locations.

The Tufts team and its partners from the City of Somerville and the Mystic River Watershed Association will undertake an aggressive information campaign to let area residents know that this information will be readily available at their fingertips.