UI researcher collaborates with CHEEC to investigate real-time sensors for drinking water  monitoring

September 16, 2020

The University of Iowa Center for Health Effects of Environmental Contamination (CHEEC), in collaboration with UI’s IIHR Hydroscience and Engineering, recently published a study demonstrating the successful use of real-time sensors to monitor nitrate, a contaminant regulated by the US Environmental Protection Agency (EPA), in drinking water.

Recent research has suggested that consumption of high-nitrate water is potentially linked to adverse health effects. 

“Nitrate in drinking water gets transformed in the human body to nitrite, which can further react with amides and amines in the bladder and the digestive system to produce N-nitroso compounds,” said CHEEC Director David Cwiertny, a professor of civil and environmental engineering at Iowa and co-author on the study.  “These compounds can be carcinogenic.  CHEEC has previously supported research that found links between drinking water nitrate levels and bladder and ovarian cancer in women. Other studies have also associated higher nitrate levels to increased risk of colorectal cancer, non-Hodgkins lymphoma, thyroid disease, and birth defects.”

Every year, Public Water Systems (PWSs) in the Midwestern United States struggle with high nitrate levels in source waters from intense land application of nitrogen-rich industrial fertilizer and manure.

“Over 60 PWS provide water to customers that exceeds 5 mg/ Lof nitrate, above which the risks of negative health effects including certain forms of cancer and birth defects have been shown to increase.  Over 260 of the state’s 880 PWSs are vulnerable to contamination,” said Chris Jones, a research engineer at IIHR and the study’s lead investigator.

The study, published in the journal Water Science & Technology, compared nitrate levels measured with real-time sensors in source and near-finished drinking water to values reported to the EPA for compliance monitoring by six different PWSs in Iowa over the span of several years. 

“We compared nitrate levels measured using field-deployed sensors to those levels measured via more traditional laboratory methods, like ion chromatography. We find really good agreement between the sensors and the traditional methods that are allowed for compliance reporting through the Safe Drinking Water Act. Between 2006–2011 traditional analysis averaged concentrations of 5.8 mg/L compared to an average of 5.7 mg/L with the sensors,” Cwiertny said.

The study also identified several benefits of using real-time sensors by PWS.  “The sensors could reduce the costs of existing approaches to compliance monitoring and reporting. These savings may be helpful for small PWS that tend to face more severe constraints on available resources.  These sensors also would make useful decision support tools for any PWS with source water at risk from nitrate contamination. Nitrate treatment strategies can be quite expensive, and you could envision how real time data generated with these sensors could help a system determine when is best to activate their nitrate treatment systems.  This could help to reduce treatment costs and ultimately lower water rates for consumers,” said Jones.

The real-time output of water quality data could also be used to better keep consumers informed. 

“The sensors would allow data to be exported and shown in real time on a utility’s homepage,” Cwiertny said. “Most importantly, this sensors provide a better means for protecting public health because they can help to better identify violations that may otherwise go undetected.”

For more information, visit https://cheec.uiowa.edu or email cheec@uiowa.edu.

CHEEC is part of the University of Iowa Office of the Vice President for Research, which provides researchers and scholars with resources, guidance, and inspiration to secure funding, collaborate, innovate, and forge frontiers of discovery that benefit everyone. More at http://research.uiowa.edu, and on Twitter: @DaretoDiscover. 

Media Note: Media interested in interviewing IWFoS developers or arranging to shoot photos should contact Strategic Communications Director Stephen Pradarelli in the Office of the Vice President for Research at 319-384-1282 or stephen-pradarelli@uiowa.edu.