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America's plumbing isn't getting any younger. At least a dozen water mains across the United States burst during the first two weeks of July alone, some flooding streets and leaving neighborhoods without running water. Experts say the country's urban water infrastructure is approaching the end of its useful life, and the time is ripe for creative new solutions to improve the system's efficiency, saving water, energy and money.

Scientists and other experts are taking on that challenge with the new Engineering Research Center for Re-inventing America's Urban Water Infrastructure.

"The intent is to show how new technologies and new management practices can change business-as-usual," said Richard G. Luthy, director of the multi-institutional center and a professor of civil and environmental engineering at Stanford. "There isn't one single investigator who can make all that happen. It takes a diverse and sizeable group."

Stanford, three other universities, and industry experts formed the consortium, which was recently awarded an $18.5 million Engineering Research Center (ERC) grant from the National Science Foundation. Their task? To demonstrate over the next five to 10 years how innovations in science and technology, along with a better understanding of institutional practices, could be implemented in an overhaul of the current urban water infrastructure.

"Our urban infrastructure needs to be rehabilitated and that will happen one way or another. This grant gives us an opportunity to do something different, something better," said Luthy.

Living filters

In addition to serving as director of the ERC, Luthy, who is a senior fellow at the Woods Institute for the Environment, will study how shellfish could help treat wastewater.

In Discovery Bay, a wetland located roughly 40 miles east of San Francisco Bay, he and other ERC researchers will test whether freshwater mussels can remove disease-causing pathogens and chemical contaminants from the wastewater that flows through the wetland.

Bivalves such as mussels and clams are like living strainers. They filter small particles out of the water and eat them. Some chemicals and pathogens found in wastewater attach themselves to floating particles, so they could become trapped within the animals' bodies or waste.

"Mussels filter a lot of water," said Luthy. "We want to demonstrate that particle-bound contaminants, be they pathogens or chemicals, will be removed."

Luthy will work on the project with a team of researchers from University of California - Berkeley, Colorado School of Mines, New Mexico State University and Stanford. The team will also investigate which shellfish are the most effective wastewater filters and how bivalves' particle-removing ability could augment, or even replace, parts of existing wastewater treatment processes.

Stormwater

The Discovery Bay wetland study is just one of the projects within the ERC that are focused on integrating natural systems into urban water treatment, storage and reuse.

"The benefit of natural systems like wetlands, aquifers and reservoirs," said Alexandra B. Boehm, an associate professor of environmental engineering and science at Stanford, "is that they can potentially achieve an engineering function like removing a contaminant but they can also be enjoyed by people and animals can benefit, too."

Boehm, is coordinating all the ERC's studies investigating natural systems. She also plans to be part of a team studying storm water harvesting. She and ERC investigators from four universities will investigate how storm water that travels through special permeable pavement is filtered, and how it moves through underground aquifers.

"People haven't really looked at how contaminants in storm water are removed or if they're infiltrating into the aquifer," Boehm said. The researchers intend to test whether permeable pavements and soil additives can effectively snag contaminants and keep them out of the groundwater. They'll look at bark, sawdust, modified clay and iron-coated sand, to name a few.

Part 2 of story … read about plans for unconventional wastewater treatment systems at Stanford.

Sascha Zubryd is a science-writer intern at the Woods Institute for the Environment.