"All members of the groundwater biotic community, comprising microorganisms, protozoans, and metazoans, potentially contribute to the natural attenuation of organic matter inputs deriving e.g. from contaminations. Since an increasing proportion of drinking water is won from groundwater, bioremediation is important for public health. Sampling groundwater however is limited compared to other habitats. Therefore modelling takes an important part in increasing conceptual knowledge on the conditions under which microbial colonies, or the protozoans and metazoans grazing on the microbes, function most effectively. Groundwater contaminant biodegradation by microbes has so far only been modelled on the population level. These models have to make average assumptions which do not represent groundwater heterogeneity adequately. Biotic features, such as the adaptive behaviour that individual microbial cells exhibit by e.g. due to changing environmental conditions, have also not been taken into account. For other communities and other environments, such behavioural adaptations have successfully been modelled using the bottom up approach of individual-based models. The research project will therefore bring together an individual-based modeller, a groundwater ecologist and hydrogeological modellers to perform simulations based on exemplary conditions in order to evaluate the biodegradation potential based on the complete ecosystem functioning. The three main aims of this project are: 1) to adapt an existing platform for individual based modelling (IbM) of biofilm, iDynoMiCs, to groundwater conditions; 2) to add further levels of the food web and functional types to this platform, e.g. grazers (belonging both to the protozoans and metazoans), and 3) to couple this platform to a groundwater reactive transport model, in order to conduct evaluations of degradation potential and management options based on groundwater ecosystem functions."