Universities to Examine Long-Term Benefits, Drawbacks of Wastewater Use

By City News Service:

UC Riverside and Israel’s Hebrew University are partnering to research the long-term viability of using treated wastewater to irrigate crops, it was announced this week.

UCR’s School of Public Policy is taking the lead in the two-year study.

“Israel has been using treated municipal wastewater in agricultural environments for 15 to 20 years,” said Kurt Schwabe, a UCR associate professor of environmental economics and policy. “If we want to understand the relationship between treated wastewater and crop yield and possible health issues, this is the place to go.”

Schwabe, who has been designated the project’s principal investigator, said researchers will analyze methods of wastewater irrigation “with an eye toward water supply reliability and maintaining water quality standards.”

“Given the integral role wastewater reuse will play in an agency’s water supply portfolio, a clearer understanding of reuse possibilities and their implications on agency costs can be helpful,” Schwabe said. “Collaborating with researchers in engineering, economics and soil science is a much more effective strategy to solve issues than a piecemeal or siloed approach.”

Israel’s wastewater applications have not been free of complications. Roughly 50 percent of farms in the Jewish state utilize wastewater, and some of them have recorded extremely high concentrations of sodium in fruits and vegetables, UCR officials said.

David Jassby, a UCR assistant professor of environmental and chemical engineering, said quality-control will be a major component of the two-year study.

“Our hope is that wastewater utilities can engineer their treatment trains to meet the demands of farmers so we can better reuse wastewater in a way that is cost-effective, rather than send it to the ocean,” Jassby said. “We hope we will be able to optimize wastewater treatment processes so they are better matched to the agricultural end uses of the water. To the best of our knowledge, no one is looking at this kind of model (in the U.S.).”

The research has taken on greater urgency in the midst of California’s four-year drought.

In an interview with City News Service last month, Israel’s consul- general for the southwest U.S., David Siegel, said 90 percent of the Jewish state’s water is recycled and “gray water” -- not potable water -- is predominately used to meet agricultural needs.

Siegel said Israeli water managers have mastered drip irrigation techniques to maximize conservation.

“We know how to stretch every last drop,” he told CNS.

In his April 1 drought emergency executive order, Gov. Jerry Brown directed the state Water Resources Control Board to implement regulations prohibiting the use of potable water to irrigate public medians and the lawns of newly constructed homes -- unless drip irrigation or microspray methods are employed.

According to Schwabe, among the participants in the UCR-Hebrew University study will be the Perris-based Eastern Municipal Water District, West Riverside County Agriculture Coalition, Orange County Water District, Rancho California Water District and US Department of Agriculture’s Salinity Lab.

The USDA awarded an initial $300,000 in support of the project, according to UCR.

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