Remediation oriented use of conceptual site models at WISMUT GmbH: Rehabilitation of the Trünzig tailings management area

Abstract

Sites with complex environmental liabilities, such as present at the former U (surface) mining and processing sites of Seelingstädt, comprising multiple sources of environmental contamination require a phased modeling approach to support the site rehabilitation activities. The rehabilitation planing is best developed on the basis of a conceptual site model that structures the sub-models approximating the remedial objects, site conditions, the contaminant transporting media (such as the receiving streams and the aquifer on the site) and combines these with the process models calculating contaminant release, transport and geo-chemical interaction. The remedial problem determines the selection of the model code and the model set up process. The need for additional remedial investigation is measured by the requirements of the remediation oriented conceptual site model, thus directing the development of the database. The methodology is outlined on the case of the Trünzig tailings management site. By performing model simulations and feasibility assessment of the potential rehabilitation measures in terms of environmental and economic gains it was possible to derive verifiable rehabilitation decisions for the site.