Contamination of groundwater resources with heavy metals, nitrate, chlorinated solvents, petroleum hydrocarbons and pesticides is widespread in both rural and urban settings and can adversely affect aquatic ecosystem and human health. For example, elevated nitrate concentrations in groundwater have been recognized and increased worldwide since the 1970s and are the most common pollution in shallow aquifers, which is an important source of drinking water.
New developments, such as shale gas extraction, may give further impacts to groundwater resources, for example through the spreading of fracking chemicals and the escape of methane to shallow aquifers (e.g. Jackson et al., PNAS 2013). Moreover, micro-pollutants, such as pesticides, consumer care products or pharmaceuticals, are introduced into groundwater systems by anthropogenic activity and have a potential for toxic effects even at low concentrations. The processes, such as biodegradation, uptake by plant roots, chemical degradation, volatilization and sorption by organic and mineral components determine the behavior of a contaminant.

A thorough understanding of the processes governing the transport and transformation of contaminants is needed to predict aquifer vulnerability, to improve remediation strategies of soil and groundwater contaminations and to address sustainable use of our water resources. This session encourages presentations of recent developments, state-of-the-art tools and techniques, and innovative instrumentation, sampling techniques and measurement / monitoring approaches to assess vulnerability, sustainability, risk and remediation approaches in the unsaturated and/or saturated zone. Of particular interest are process studies using microbial activity, reactive transport and flow analysis, as well as the use of isotope signatures and analogue compounds as tracers for contaminant source and for process identification / quantification.

In a subsession, special attention is paid to the potential and actual observed impacts of shale gas extraction on groundwater resources in order to discuss scientific progress gained in design studies and actual shale gas extractions. This includes risk analyses of shale gas extractions in relation to water resources, hydrogeological, hydrogeochemical and isotopic impact studies, using lab, field, and/ or model approaches, and design and data analysis strategies for effect monitoring. By sharing information of different geological and hydrochemical settings in Europe and the US we ultimately aim to contribute to wise decision making based on scientific grounds.