Researchers seek to engineer wastewater treatment for agriculture
A multi-discipline group of researchers at the University of California, Riverside and the Hebrew University of Jerusalem have launched an investigation into the use of treated wastewater in agriculture. They aim to produce findings that could form the basis of sound water reuse policies.Associate professor of environmental economics and policy and the project's principal investigator, Kurt Schwabe, said the project will review previous studies of the use of treated wastewater to improve the reliability of local water supplies.
The project - Enhanced Resilience of Local Agricultural Water Supplies through Reuse of Municipal and Agricultural Water: A Dynamic Economic Analysis - will study also the impact of treated wastewater on crop yields and evaluate the performance and economics of new technologies for using treated wastewater in agriculture.
The project, will initially be funded with about US$ 300,000 from the US Department of Agriculture's National Institute of Food and Agriculture-Binational Agricultural Research and Development Fund partnership with Israel.
"Israel has been using treated municipal wastewater in agricultural environments for 15 to 20 years. If we want to understand the relationship between treated wastewater and crop yield and possible health issues, this is the place to go," said Schwabe.
"The long-term goal is to determine the most cost-effective approach to utilizing treated wastewater with an eye toward water supply reliability and maintaining water quality standards," said Schwabe.
To gain a "clearer understanding of reuse possibilities and their implications on agency costs" required an interdisciplinary approach he added. His team includes researchers in engineering, economics and soil science.
Although many communities and water agencies are contemplating the expansion or introduction of treated wastewater for outdoor uses, "there has been no holistic approach to bringing agriculture into the picture," Schwabe said.
Treated wastewater is used on about half of Israel's agricultural land and farmers there are seeing decreasing crop yields and excess concentrations of sodium in fruits and vegetables on fields irrigated with wastewater, according to assistant professor of environmental and chemical engineering and co-principal investigator on the project David Jassby.
Jassby will study various wastewater treatment methods with an emphasis on matching water- quality to the requirements of certain crops and seeking ways to tailor wastewater treatment to provide water for specific crops.
"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. To the best of our knowledge, no one is looking at this kind of model," Jassby said.
The passage of the state water bond measure, Proposition 1, in November 2014 and Governor Brown's subsequent drought declaration signals greater attention on the need to reuse wastewater to improve local water supply reliability and reduce reliance on imported water, Schwabe said.
"We see this project as responding to that with a science-based approach," he said. "The more you recycle, the less you're vulnerable to fluctuations in water availability."