Artificial sweeteners as potential tracers in groundwater in urban environments

SummaryThere is little information available on the prevalence of artificial sweeteners in groundwater, though these compounds may prove to be useful tracers of human wastewater, especially in urban settings with complex hydrology. In this study, the artificial sweetener acesulfame was detected in groundwater at all eight urban sites investigated (from five different urban areas in Canada), often at high concentrations (i.e., μg/L-scale). In a municipal wastewater plume at Jasper, Alberta, acesulfame was strongly correlated with chloride and was positively correlated with other wastewater-related contaminants indicating that this sweetener has potential to be a good tracer of young wastewater (<20 years residence time) in Canada. Three other artificial sweeteners were detected in urban groundwater: saccharin at six of the sites, sucralose at three sites, and cyclamate at five of seven sites where it was analyzed. The occurrence of sucralose may have been affected by its detection limit, which was much higher than for the other sweeteners. These results, and those of a parallel study, are the first reported detections of saccharin and cyclamate in groundwater, and suggest that these sweeteners may be more common than previously anticipated. In general, fewer samples from each site contained these other three sweeteners compared to acesulfame. At Barrie, Ontario, adjacent to an old landfill, the concentration of saccharin was higher than acesulfame in many samples. These results suggest that analyses of multiple sweeteners, rather than just acesulfame, may provide useful information on contaminant sources and groundwater conditions in urban settings. Further work is needed to address this potential use.

Research highlights
► Sweetener acesulfame found in urban groundwater at all sites, three with known wastewater sources.
► Frequent detection supports earlier proposition that acesulfame is ideal tracer for wastewater.
► Strong correlation of acesulfame with chloride in a wastewater-affected groundwater plume.
► Detections of saccharin and cyclamate in groundwater at the majority of the study sites.
► Potential for multiple sweeteners to distinguish various wastewater and non-wastewater sources.