Abstract: In der Regenzeit 1991/1992 wurden überraschend im Bereich des australischen Goldbergwerks Pine Creek saure Grubenwässer festgestellt, die eine ernsthafte Umweltgefährdung und einen deutlichen Anstieg bei den Betriebskosten verursachten. Diese sauren Grubenwässer traten als Folge von Laugungserscheinungen in den Halden auf. Zur Verminderung der Reaktionsfähigkeit der sulfidischen Berge wurde beschlossen, die Halden mit mehreren Schichten inerten Materials geringer Permeabilität abzudecken. Diese Abdeckung wurde anschließend verdichtet und begrünt. Bei den späteren Abbauarbeiten wurde eine prophylaktische Minimierung der begünstigenden Reaktionsbedingungen vorgenommen. Es wurde eine Integration von Abbau und Sanierungsmaßnahmen realisiert, bei der offene Tagebauflächen mit Haldenbergen verfüllt wurden. Die haldengefüllten Tagebaurestlöcher wurden außerdem teilgeflutet, um den Sauerstoffzutritt zu minimieren. Aus den gewonnenen Erfahrungen wird die Schlußfolgerung gezogen, das AMD-Problem bereits in der Planungsphase zu berücksichtigen und umfassende Untersuchungen einzuleiten. Es sind nicht erst im Stadium der Sanierung, sondern bereits bei den Abbauaktivitäten geeignete Maßnahmen einzuleiten, um unangenehme Überraschungen durch saure Grubenwässer, die übrigens sehr teuer werden können, zu vermeiden.

Abstract: Parts of the Norwegian river Gaula are strongly polluted from former mining activity in the area. In the most polluted parts of the river the concentration levels of Cu and Zn in 1986-1987 were up to 155 mu g l (super -1) and 186 mu g l (super -1) , respectively. In 1989 the spoil heaps in the mining area were covered with protective layers of moss-covered plastic. In 1991-1992 the concentration levels of Cu and Zn had decreased by 75% and 65%, respectively. Animal life in the polluted area seemed to be strongly affected by the trace metals in 1986-1987. The 1991-1992 results showed a marked increase in the number of species and in the number of individuals of each species of Ephemeroptera and Plecoptera, compared with the results from 1986-87. Good correlations were found between the concentrations of Cu in the water and both the number of species and the number of individuals of Ephemeroptera and Plecoptera. Analysis of the species Baetis rhodani, Diura nanseni and Rhyacophila nubila showed an average total dry weight content of Cu up to 264 mu g g (super -1) , of Zn up to 1930 mu g g (super -1) and of Cd up to 16 mu g g (super -1) . The contents of the three trace metals were significantly different from one species to another and in part between the stations for each species. In 1987 trout died after an exposure of one to two days on three test sites in the river, whereas in 1991-1992 40-75% of the trout survived an exposure period of several weeks at two of the sites. Electrofishing in 1991-1992 indicated recolonization of trout in the lower parts of the former affected and uninhabitable area.

Abstract: Parts of the Norwegian river Gaula are strongly polluted from former mining activity in the area. In the most polluted parts of the river the concentration levels of Cu and Zn in 1986-1987 were up to 155 mug l-1 and 186 mug l-1, respectively. In 1989 the spoil heaps in the mining area were covered with protective layers of moss-covered plastic. In 1991-1992 the concentration levels of Cu and Zn had decreased by 75% and 65%, respectively. Animal life in the polluted area seemed to be strongly affected by the trace metals in 1986-1987. The 1991-1992 results showed a marked increase in the number of species and in the number of individuals of each species of Ephemeroptera and Plecoptera, compared with the results from 1986-87. Good correlations were found between the concentrations of Cu in the water and both the number of species and the number of individuals of Ephemeroptera and Plecoptera. Analysis of the species Baetis rhodani, Diura nanseni and Rhyacophila nubila showed an average total dry weight content of Cu up to 264 mug g-1, of Zn up to 1930 mug g-1 and of Cd up to 16 mug g-1. The contents of the three trace metals were significantly different from one species to another and in part between the stations for each species. In 1987 trout died after an exposure of one to two days on three test sites in the river, whereas in 1991-1992 40-75% of the trout survived an exposure period of several weeks at two of the sites. Electrofishing in 1991-1992 indicated recolonization of trout in the lower parts of the former affected and uninhabitable area.