Engineers propose reclaimed wastewater to improve resilience

Reclaimed wastewater could make supply systems more resilient, according to researchers in Houston. What did they come up with?

Reclaimed wastewater could make supply systems more resilient, according to researchers in Houston.

Houston’s water and wastewater system could be more resilient by developing hybrid urban water supply systems that combine conventional, centralized water sources with reclaimed wastewater. This is according to a study by Rice University engineers published in Nature Water.

“Such a system will save energy and help reduce the use of freshwater, a commodity that is becoming critically important around the world,” said Qilin Li, professor of civil and environmental engineering and co-director of the Nanosystems Engineering Research Center for Nanotechnology Enabled Water Treatment (NEWT) at Rice. “Our research shows that such a system is more resilient against disruptive events such as hurricanes and flooding. It exhibits lower severity, range of impact and duration of substandard performance when disruption happens.”

Leonardo Dueñas-Osorio is a civil and environmental engineering professor at Rice and a co-author of the study. He said hybrid water supply systems are more resilient than conventional centralized systems.

“We used Houston’s municipal water system as a case study. The goal was to explore the impact of various disruptions, including pump station failures, pipe leakage and source water contamination,” Dueñas-Osorio said.

Reclaimed wastewater to mitigate vulnerable infrastructure

Li and her collaborators have identified vulnerable components in Houston’s existing water and wastewater system and proposed mitigation strategies. The city’s aging infrastructure compounds the urgency.

Nationally, the typical age of failing water mains is about 50 years, while the average age of the 1.6 million miles of water and sewer pipes in the U.S. is 45 years, according to the study. Some six billion gallons of treated water ⎯ roughly 15% of the U.S. daily public water supply ⎯ is lost each day from leaky pipes.

In addition, large cities worldwide face unprecedented challenges as global climate change, population growth, and continuing urbanization rapidly increase water demand, triggering water access issues and a growing financial burden due to water systems’ maintenance and upgrade needs.

On a small scale, cities worldwide, including El Paso, have already enabled the reclamation and reuse of municipal wastewater for drinking and non-potable uses such as irrigation.

“Decreasing dependence on already stressed surface and groundwater resources has become increasingly important,” Li said. “An important challenge is to figure out how to best implement wastewater reclamation activities. The goal is to enhance the sustainability and resiliency of big city water infrastructure. Our recent research shows the benefits of decentralized wastewater treatment and reuse.”

The study’s co-authors include Lauren Stadler, assistant professor of civil and environmental engineering at Rice; Rice doctoral alum Xiangnan Zhou; and Lu Liu, assistant professor of civil, construction and environmental engineering at Iowa State University.

Related Articles:

Send this to a friend