3. Overall Project Description
In 1992, the Queensland Government (the State) took on management of the legacy issues at the Mount Morgan Mine and the site is currently managed under the AMLP (Queensland Government, 2020). In 2003, the State developed a Rehabilitation Plan (Unger et al, 2003) for the Mount Morgan Mine which emphasised private investment for reprocessing of tailings and waste rock dumps to improve overall environmental outcomes. The presence of heavy metals and sulphur bearing compounds (iron, pyrite, zinc, molybdenum and others) within tailings and waste material have caused a number of legacy issues on the site, predominantly concerned with the issue of acid rock drainage (ARD) causing water quality impacts in the receiving environment. ARD is the key environmental concern at the mine site, posing a significant adverse risk to downstream catchments, namely the Dee, Don and Dawson rivers. ARD is caused by oxidised sulphide minerals in rocks and soils being mobilised by water moving over or through the sulphide minerals (Unger et al., 2003). This sulphidic waste material was dumped across a large area, including the slopes of relatively steep hills in the upper reaches of the Dee River catchment – factors which have facilitated its oxidisation and transport offsite. Heritage Minerals plans to recommence operations at the Mount Morgan Mine through tailings reprocessing following the construction of processing plant and associated mine infrastructure that commenced during 2024. Heritage Minerals initial focus is to recover gold from historic latent tailings areas at Mundic Sulphide Tails (Mundic Gully), No. 2 Mill Tailings Dam (No. 2), Shepherds Gully Tailings Dam (Shepherds Gully), Red Oxide Tails (Red Oxide) and Sandstone Gully. Through Heritage Minerals activities, latent tailings and waste rock recovery and reprocessing at Mount Morgan is expected to result in the reduction of contaminant sources via the reprocessing of mineralised tailings dams and remediation of operational areas, which will reduce the volume of mine affected surface water runoff. As a result, it is anticipated that surface water quality of the Dee River will improve during and post mining. Overall Project History Mount Morgan Mine has a long history spanning from the commencement of mining operations in 1882 and was the primary reason for the establishment of the adjacent Mount Morgan township. The town of Mount Morgan was the administrative centre of the Mount Morgan Shire until 2008 when it was amalgamated with neighbouring local government areas to form the Rockhampton Regional Council. 3.1 Mount Morgan Limited (MML) operated the mine until its closure in November 1990. In that time, approximately 250 tonnes of gold and 360,000 tonnes of copper were extracted, generating approximately 133 million tonnes of waste rock and tailings (AARC, 2017b). Operations were a combination of underground and open cut mining. These operations resulted in impacts on environmental values at the site and the surrounding area, including the Dee River. Handover to the State Following production cessation in March 1991, the State and MML reached an agreement under which: ∕ MML would carry out decommissioning and environmental management works in accordance with an agreed rehabilitation plan; and 3.1.1
Project number: 25B061
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