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A three tiered, iterative Environmental Risk Assessment methodology, including preliminary Qualitative Risk Assessment, Quantitative Hazard Assessment and Site Specific Quantitative Risk Assessment, was established to assess the environmental risk of point and diffuse pollution of mining origin at catchment scale [1]. The model site was an abandoned Pb and Zn sulphide ore mine in Gyöngyösoroszi, Toka-valley, NE Hungary [2]. The Integrated Risk Model considers the sources identified by the GIS-based (Geographical Information System) pollution map, the transport routes shown by the GIS-based flow accumulation model and the receptors of different land uses in the catchment. The site-specific quantitative risk was characterised by the Soil Testing Triad [3]. The three elements of the Triad are: physico-chemical analyses of the soil and the contaminants, the biological characterisation and ecotoxicity testing of the contaminated soil, measuring the response of single species in laboratory bioassays, the natural response of the soil microflora and plants or the dynamic response of the whole soil in microcosms. The Triad approach strongly supports the characterisation of the site specific risk as well as the selection and planning of the suitable remediation option.

An Environmental Risk Management methodology was developed for the Toka catchment area, an abandoned base metal mining site in Gyöngyösoroszi, Hungary. The postmining activities on the Hungarian site require the management of both the point and diffuse sources. The mobile Cd and Zn content of the mine waste, soil and sediment transported by water pose the highest environmental risk in the area. The approach is „GIS based” (Geographical Information System) and „catchment scale”, using a three tiered, iterative Environmental Risk Assessment methodology. The model parameters of the metal transport were determined in leaching microcosms. The risk reduction concept aims at reducing the runoff water quantity and contamination by removal of the point sources and chemical & phytostabilisation of the residual and diffuse pollution. The planning of the field application was based on the results of the stabilisation microcosms.