Applicability of geochemical techniques and artificial sweeteners in discriminating the anthropogenic sources of chloride in shallow groundwater north of Toronto, Canada.

Elevated levels of chloride concentration due to anthropogenic activities including the road salts, septic effluent and agricultural sources are common in shallow groundwater of the recent glacial deposits north of Toronto, Ontario, Canada. Identifying suitable techniques for discriminating the source of the chloride concentration helps to better plan the protection of groundwater in the area. This paper examines the applicability of geochemical techniques with emphasis on Panno et al. (Ground Water 44: 176-187, 2006) and Mullaney et al. (2009) graphical approaches for discriminating the sources of chloride with known causes of impacts. The results indicated that the graphical methods developed using Cl-, Br- and/or total nitrogen (N) could identify the combined sources of road salts and septic systems. However, discriminating between the road salts, septic effluent or agricultural sources needs to be complemented by other techniques including the artificial sweeteners and isotope tracers.