RISK-BASED INVENTORY AND ASSESSMENT OF MINE SITES IN THE EUROPEAN UNION. METHODS AND APPROACHES

In historic mining areas like in Europe mine closure and abandoned mines have grown a major concern for contamination, as reflected by the new EU Mine Waste Directive (Directive 2006/21/EC) requiring the risk-based inventory of closed and abandoned mine waste sites. Associated problems include the long-term release of contaminated acid mine drainage (AMD) effluents and accidental pollution by tailings dam failure, among others. In addition to the environmental complexity of mine sites, problems of bridging the gap between detailed site-specific investigation and regional-scale assessment, identification of key parameters (indicators), long-term risk-based monitoring, application of existing geological information and harmonization of sampling, analysis and data processing methods have to be addressed. Contamination Risk Assessment (RA) studies the combined effect of the probability of contamination and the significance of toxic impacts along the contamination source-pathway-receptor chain. It is generally recognized that risk-based inventory of mine sites should enable the ranking of mine sites (identification of ‘hot spots') and it should follow a tiered approach proceeding from preliminary risk screening to more detailed site studies. This paper compares several national and international risk-assessment methods in order to conclude on the main criteria for developing a cost-effective and efficient risk-based inventory of mine sites.