Environmental Remediation of Abandoned Mines in Portugal - Balance of 15 Years of Activity and New Perspectives

摘要

Portugal has an important legacy of degraded former mining sites with clear environmental and public health impacts and safety problems. Since 2001 they are being subjected to environmental remediation operations by EDM- Empresa de Desenvolvimento Mineiro, S.A. under a legal regime of concession assigned by the Portuguese State and approved by the Decree-Law N° 198-A/2001.From an inventory of 175 abandoned mining areas, 61 of which in radioactive minerals and 114 of polymetallic massive sulphides mines, EDM had until 2015 remediated most of the old mines with more significant negative environmental and public health impacts, having concluded the remediation works in 90 mining areas and there were ongoing remediation works in 10 mining areas. An important effort has been made to achieve these results and the definition of a clear strategy for the remediation of the old mining areas as well as comprehensive set of characterization studies, plans, and detailed projects were key factors. Additionally a pre and post remediation environmental monitoring and maintenance is ongoing in the old mining areas that include the operation and maintenance of several mine water treatment plants.This paper briefly presents EDM adopted model and strategy for the environmental remediation mission, the most representative actions concluded in Portuguese old mining sites remediation with different and adapted solutions for mining wastes confinement and mine water management, including active and passive treatment systems, and a balance of these fifteen years of intense activity, lessons learned and perspectives for the future.