6.4.2.1.3.
Historic and Surrounding Land Uses
More than a century of mining at Mount Morgan has put the surrounding land in a degraded state, with
contaminated runoff and seepage present. Little is known regarding the site history prior to mining
operations commencing in 1882, however it is assumed that the undisturbed areas was consistent with
the undisturbed areas adjacent to the site towards the north and west.
For the purposes of this amendment application, the pre-mining land use is the use of the land prior to
its disturbance by Heritage Minerals and therefore prior to the point in time relevant to rehabilitation
obligations. That pre-mining use is a decommissioned mine managed by the DNRMMRRD in
accordance with the Abandoned Mines Land Program. The land is heavily impacted by from historic
mining with unrehabilitated waste dumps and contaminated water impoundments. The DNRMMRRD
carries out remediation activities including contaminated water seepage interception, contaminated
water treatment, heritage building maintenance and land and infrastructure management. The
DNRMMRRD has developed numerous revegetation plans based on years of trials and consideration
of the surround ecosystems which the revegetation section in 6.2.4.2 has aligned with.
6.4.2.1.4.
Description of Nominated PMLU
Based on an understanding of relevant land use strategies, regional plans and considering the
surrounding land uses, the nominated PMLU for the Upper Mundic Gully TSF is ‘Native Ecosystem’.
Given the challenges associated with achieving a PMLU that matches natural historic ecosystems, as
published in the Office of the Queensland Mine Rehabilitation Commissioner, Native ecosystem
rehabilitation in Queensland implications for leading practice September 2023, a hybrid ecosystem is
proposed that meets DNRMMRRD expectations.
6.4.2.2. Rehabilitation Methodology
The performance outcomes for Land provides for an obligation to achieve a safe, stable and non-
polluting landform iv. able to sustain an appropriate land use after rehabilitation or restoration. The
proposed rehabilitation commitments are as follows:
• Completely backfilled with tailings. PAF waste rock exposed during construction transferred
to void;
Water removed from surface;
•
• Dry cover – store and release installed; and
Drainage system constructed.
•
Based on these proposed EA conditions, the rehabilitation methodology for the Upper Mundic Gully
TSF will involves the following aspects:
• Fill the TSF to the maximum permissible RL to achieve the final landform;
• Shaping of the tailings surface to provide a direct flow path to the spillway and minimise or
prevent ponding of water;
• Runoff management systems installed on the embankment;
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Wulguru Technical Services Pty Ltd – Supporting Information to Amend an Environmental Authority
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