Rum Jungle mine site remediation: relationship between changing water qualith parameters and ecological recovery in the finniss river system

摘要

The Finniss River system in tropical northern Australia has received `acid-drainage' contaminants from the Rum Jungle uranum/copper mine site over the past 4 decades. Following mine-site remediation that began in 1981-82 the annual contaminant loads of sulfate, Cu, Zn and Mn have declined by factors of 3, 7, 7, and 4, respectively over 1990-93, compared to the 1969-74 pre-remediation loads. Comparison of the frquency distributions of contaminant water concentrations over these pre- and post-remedial periods have shown varyig degrees of reduction in the highest level following mine-site remediation, the are consisten with reductions in their annual-cycle loads. Among the three selected major metal contaminants the reductions in maximum water concentrations are most pronounced for Cu. The demonstrated reductions in the highest water cocentrations of all four contaminants are also associated with previously reported ecological improvement in the Finniss River system, compared to the benchmark of environmental detriment established in 1973/74, prior to the beginning of remediation at the mine iste.