The Grapevine

Artificial Sweeteners Help Identify Treated Wastewater Discharged In Local Streams

A recent study by the University of Waterloo found that 13 percent of underground wastewater from septic systems used in rural areas, particularly in rural Southern Ontario, entered the local streams. Despite the elaborate treatment system attached to septic tanks, this is considered a potential source of water contamination in the streams. 

The scientists were able to trace the wastewater easily with the help of artificial sweeteners that make it easy to differentiate from the stream water. 

"Artificial sweeteners are one of the best tracers of wastewater in the environment because they don't completely break down in the body or in wastewater treatment systems. They are prevalent in many common consumer products, so we find them in every wastewater sample we look at," John Spoelstra, adjunct professor of Earth and Environmental Sciences at Waterloo, said, as quoted in the news release. 

"In many cases, residual artificial sweeteners are the most reliable indicator of the waters' septic system origin once released into the environment."

What The Study Found

The researchers visited 173 stream sites and collected 294 samples across southern parts of the state of Ontario in Canada. Traces of artificial sweeteners such as acesulfame, saccharin, cyclamate and sucralose were found. About 91 percent of the samples had at least one of the compounds.

According to the researchers, the gathered samples of artificial sweeteners originated from the septic system’s effluents since the stream sites were not connected to municipal wastewater treatment plants. Of all the sweeteners detected, acesulfame was the most abundantly present in 91 percent of the samples. 

“Using acesulfame concentrations, we calculated that approximately 13% of the septic effluent water generated in rural Southern Ontario eventually ends up in local streams, however this is likely a conservative estimate,” the researchers explained in the study published in the latest edition of Journal of Hydrology X.

The other sweeteners were not found in the same quantity. Saccharin was identified in 27 percent, cyclamate was found in 8 percent and only a mere 3 percent of the samples had sucralose content. 

"High levels of sweeteners indicate an elevated presence of wastewater in the stream. Therefore, in some cases, more testing may be warranted to ensure that harmful wastewater contaminants, such as pathogens and pharmaceuticals, are not present," Spoelstra added. 

"The prevalence of artificial sweeteners in streams around rural Southern Ontario is a reminder that our water use is a cycle, and what we put into our environment doesn't just disappear," Spoelstra cautioned. 

lake-2063957_1920 According to a study conducted by University of Waterloo, 13 percent of water in streams comes from septic systems in rural areas in Southern Ontario, Canada. Artificial sweeteners were used in the identification process. Pixabay