Mt Lyell is a copper mine in the north west of Tasmania it was originally operated by the Mt Lyell Mining and Railway Company as a gold mine. It operated for over 100 years, 1893 – 1994 disposing of the mine waste/ tailings directly into the King River. The acid producing rock or sulphides which are common with copper ore and waste rock has devestated the King river through the chemical process known as acid mine drainage (AMD). AMD and heavy metal contamination from this mine continues to occur and impact on the King River, Queen River and Macquarie Harbour.
In 1994 the mine was abandoned, shortly after through an agreement with the State of Tasmania the mine was signed over to Copper Mines of Tasmania who then developed an underground mine known as Prince Lyell. In 1999 following financial difficulties CMT sold M tot Lyell an Indian company – Sterlite Industries who have developed the mine further. The current mining operating at Mt Lyell includes the mining and milling for copper, gold and silver. The underground mine is 1000 meters deep with a 6.5 kilometre decline to the crusher. Ore is crushed underground and then lifted up 600m up a shaft.
Riverine tailings disposal, the dumping of tailings into river systems at Mt Lyell stopped in 1994. The current mine disposes of tailings in a tailings dam at Princess Creek, a dam designed and constructed by Shaw Contracting.