The Artificial Sweetener Acesulfame as Marker of Domestic Wastewater in Groundwater

To assess sources and magnitude of possible groundwater contamination, chemical markers have proved to be useful. A chemical that is used in everyday life, the artificial sweetener acesulfame, may be ideally suited for detection of traces of domestic wastewater in natural waters. The compound was found ubiquitously in wastewater, surface waters, and groundwater from Switzerland. Acesulfame was not eliminated in wastewater treatment plants (WWTPs), and was quite persistent in lakes. Concentrations in lakes increased with population in the catchment area and decreased with water throughflow, i.e., concentrations were proportional to the ratio population per throughflow, a measure for the actual anthropogenic burden of a lake by domestic wastewater. Moreover, acesulfame was detectable in 65 of 100 groundwater samples. Highest concentrations of up to 6 μg/L, corresponding to a wastewater burden of ≈30%, were observed in areas with significant infiltration of river water, where the infiltrating water received considerable discharges from WWTPs. Given the currently achieved detection limit of ≈0.01 mg/L, presence of ≥ 0.05% wastewater can be traced in groundwater.