Problems to be solved
Contaminated land in Europe poses a serious problem with respect to soil quality and the risk of spreading of pollutants into other compartments of the environment. The major concern at most contaminated sites is the risk of groundwater pollution by organic and inorganic compounds. Since, the remediation of all of the contaminated sites in Europe is economically not feasible, groundwater risk assessment procedures are needed for the ranking of sites, decision making on further use and remedial actions. In contrast to existing procedures this project concentrates on the development of methodologies for the assessment of the mobile contaminant fraction in contaminated soil and waste material. (i.e. the contaminant fraction that would reach the aquifer). It will allow the determination of the long-term contaminant release rates and the overall emission of pollutants into the groundwater at contaminated sites. The most important innovations expected will be more harmonized and integrated guidelines for groundwater risk assessment in Europe and beyond.
Scientific objectives and approach
The procedures to be developed take the form of a scenario approach, as it is intended to be generally applicable to different situations in terms of classes/combination of pollutants and site-specific conditions, such as climatic conditions, permeability and distance between contamination and groundwater table. Such a scenario approach will allow the determination a priori whether; under given site conditions (subsurface permeability, distance to groundwater table, type of material) and contaminant properties (volatile / non-volatile / water soluble etc.), a minor, medium or high risk of groundwater pollution exists. The validation of these new risk assessment procedures will be done
1) in a well controlled field experiment which comprises an emplaced source of a hydrocarbon mixture consisting of volatile to semi-volatile, (partly) biodegradable compounds,
2) laboratory and field investigations for the quantification of contaminant transfer rates across the capillary fringe for specific scenarios and
3) column leaching tests for the quantification of the mobile contaminant fraction in various contaminated soils and waste materials (e.g. slag, bottom ash, construction/recycling materials). To cover as many different site-specific-scenarios as possible, the project involves numerical modelling for vapour phase contaminant transport in the unsaturated zone and long-term leaching of contaminants from specific materials.
The most important deliverables of the project will be guidelines for groundwater risk assessment which for certain scenarios, compound classes and material types does not require or requires only minor field or laboratory investigations. Therefore it would significantly reduce the costs to society for dealing with the legacy of industrial pollution. The end-users will be the governments/regulators and finally the citizens of Europe who benefit from a harmonized, more rational/economic and integrated approach to environmental regulation.
Funding SchemeCSC - Cost-sharing contracts
1755 ZG Petten