Determining risk of using treated water for irrigating fresh food crops

posted on August 7, 2012 10:39am

Fresh water is a precious natural resource. It’s also finite.

Producers depend on natural water sources to irrigate a number of crops, but a growing scarcity of water is leading to restrictions on the amount of water that agriculture can use and from what sources it can be drawn. An alternative is to use treated municipal wastewater to irrigate crops, but antibiotics and other pharmaceuticals present in this wastewater could accumulate in fresh food crops entering the customer food chain.

Before growers can sustainably utilize treated wastewaters as an irrigation source, researchers need to discover the roles that plants play in amassing and breaking down antimicrobial residues.

Dawn Reinhold, assistant professor in the Department of Biosystems and Agricultural Engineering, is heading a research project designed to characterize how much and what types of antimicrobials accumulate on fresh fruit and vegetable crops irrigated with treated municipal wastewater.

The study will also compare these findings to other studies of crops harvested from soils where biosolids were applied. Findings from the various assessments will be synthesized according to the human health risk of exposure to antimicrobials.

“Repurposing treated municipal wastewater for irrigation could also help remedy the negative impact that it has on aquatic ecosystems when it’s discharged directly into surface waters,” Reinhold said. “Land applying these waters instead would allow communities of soil microbes to slowly break down the antimicrobials. Findings indicate that soils have greater capacity to handle these wastes and break down the antimicrobials. The capacity of aquatic ecosystems to assimilate antimicrobials without adverse effects is currently being exceeded.”

The U.S. Department of Agriculture is funding this project.