Research Projects Tackle Reclaimed Water Issues

Return to AWR Winter 2016

Concerns about the quality of reclaimed water are getting research attention in two very different projects selected for funding by the University of Arizona Water Resources Research Center.  The WRRC provides research grants up to $10,000 each under the Water Resources Research Act, Section 104(b) with funding from the U.S. Geological Survey. The 104(b) program’s major goals are to foster research on water and related issues of importance to the state and region and to encourage the entry of students and young scientists into the field of water resources.

The first project, proposed by Robert Arnold, UA Professor of Chemical and Environmental Engineering, and David Quanrud, Associate Research Scientist in the School of Natural Resources and the Environment, investigates the natural processes by which trace organic contaminants (TOrCs) in treated wastewater are reduced by exposure to sunlight. The project takes the first steps toward identification of the circumstances that favor removal of TOrCs and development of mathematical representation of the process. The work consists of a series of controlled experiments in which defined mixtures of organic matter found in treated wastewater and representative TOrCs or indicator compounds are exposed to well-characterized light sources. The researchers then measure the rate of disappearance of the TOrCs. Software will be written to simulate the experimental reactions, and analyses will provide a foundation for future work. Results are intended to inform management of water quality in surface waters that received treated wastewater. Understanding natural removal of TOrCs would also be useful in developing cost-effective methods for restoring water quality of reclaimed water prior to potable reuse.

A project led by Channah Rock, UA Associate Professor /Specialist in Soil, Water and Environmental Science, with Natalie Brassil, Arizona Cooperative Extension Assistant, is part of a larger research program exploring the risks associated with using reclaimed water for irrigation of food crops. The investigators will be developing practical tools for assessing and mitigating the risks faced by growers, field managers, food safety coordinators, and irrigators. Based on previous and on-going research, the work will make connections with research users through focus groups where concerns related to recycled water for produce irrigation will be identified. An analysis of focus group data will provide the foundation for a risk assessment and development of a tool-kit of best management practices. 

Work on these projects will begin in March 2016 and results are expected by February 2017.