Groundwater quality degradation is a well-recognized phenomenon and has received considerable attention since the industrial revolution. In spite of this, many aspects concerning the understanding and management of groundwater as a resource remain complex, and adequate information, in many cases, remains elusive. Strategies to protect and manage groundwater quality are often based on limited data and thus restricted system knowledge.
As questions remain about the behaviour and prediction of well-known groundwater contaminants, new concerns around emerging contaminants are on the increase. In urban, industrial and agricultural areas especially, groundwater quality is widely compromised by anthropogenic impacts. Water management in such areas is recognized as a very complex task, in terms of different spatial and temporal scales, as well as understanding the input mechanism, transport and attenuation processes: crucial for sustainable groundwater management. The residence time of contaminants within groundwater bodies can be anywhere from weeks to decades, depending on physico-chemical properties of compound and environmental conditions. It is therefore well-accepted that subsurface heterogeneity necessitates the application of multiple tracers and methods to minimizing uncertainties and to uncovering subsurface processes that would not have been identified by the application of e.g. only one tracer. Thus, although contaminants are typically unwanted, they can provide crucial insights into flow and transport processes within aquifers.
This presentation highlights some of the key contaminants that originate from anthropogenic activities, reviews some of the major controls on groundwater contamination, and includes a case study that addresses historic and emerging issues in contaminant hydrogeology.
Christian Moeck1, Mario Schirmer1,2
1Eawag, Department of Water Resources and Drinking Water, Swiss Federal Institute of Aquatic Science and Technology, Switzerland; 2University of Neuchâtel, Centre of Hydrogeology and Geothermics (CHYN), Switzerland