Determining the long-term impact of historic mining on water quality: a case study on Mt Lyell, Western Tasmania, Australia

The Queenstown Mount Lyell Mining and Railway Company, established in 1893, was the dominant copper mining company of the Tasmanian West Coast from until 1994. It produced more than a million tonnes of copper, 750 tonnes of silver and 45 tonnes of gold. A by-product of these commodities were vast quantities of mine waste including approximately 53 Mt of waste rock , tailings and slag material, the latter two of which were disposed of to the Queen-King river system between 1916 and 1994. In total, 95 Mt of sulphidic tailings, 1.4 Mt of smelter slag and nearly 10 Mt of mine-impacted top soil were discharged. Currently, these pyritic waste materials reside in overbank, river bottom and delta deposits associated with the Queen-King rivers and delta