The RESPONSE project deals with the transport of point source contaminants in soils and groundwater. Point source contaminations result from historical or current activities and constitute a variety in forms, areas and contaminants involved (e.g. landfills, industrial facilities, storage tanks, disposal of hazardous waste). The large numbers of confirmed and potential point sources pose risks to human health and the environment. Therefore, new methods for assessing the migration potential of contaminants are needed.
Groundwater quality monitoring around contaminated sites is typically done by sampling piezometers. Modelling approaches can help to predict the spatial and temporal evolution of contamination plumes, design remediation strategies and assess health and environmental risks. Reactive transport models can potentially improve the prediction of contaminant routes, as they explicitly account for chemical reactions during the transport. In spite of recent advances, real-world applications remain scarce as these require large numbers of site-specific parameters.
The aim of RESPONSE is to improve the use of reactive transport models that simulate the fate of inorganic and organic contaminants in soils and groundwater. More specifically, the project aims to (1) identify the minimum amount of site-specific parameters needed to predict reactive transport of inorganic pollutants (e.g. heavy metals) and (2) improve/simplify the modelling of transport of xenobiotic (or artificial) organic pollutants (e.g. hydrocarbons and pesticides). The transport of XOCs is particularly complex to model due to the effects of microbial interactions.
The methodology involves both experimental and modelling aspects. Three case studies in shallow groundwater environments will be selected for testing. Regarding inorganic contaminants, RESPONSE will test whether reactive models can predict transport adequately, based on a minimum amount of generic data. For organic contaminants, RESPONSE will focus on the plume fringe concept (i.e. the occurrence of local conditions of enhanced microbial activity and biodegradation at the fringe of plumes: aim is to develop a simplified approach to infer the redox zonation and plume fringe in polluted aquifers.
RESPONSE will focus on typical groundwater pollution problems encountered around old municipal landfill sites and cemeteries. Municipal landfills can still release hazardous pollutants such as heavy metals and XOCs, even if they are covered by fresh ground layers after abandonment. Cemeteries can be considered a special case of landfill, releasing various compounds to the environment such as arsenic, mercury, bacteria, viruses and herbicides. Both location types are potential point sources for mixed groundwater pollution, typically including high concentrations of dissolved organic carbon (DOC), heavy metals and XOCs.
