5.6.4. Groundwater Modelling
An existing groundwater flow model for the site was prepared by Robertson GeoConsultants during
April 2011. Potential changes to the hydrological regime as a consequence of latent tailing excavations
and TSF operation are considered immaterial as the hydrological regime is significantly affected by the
seepage interception that is maintained by the State and the water treatment system that reduces the
standing water level with in the OCP.
This groundwater flow model was used to generate a closed water balance for the Mount Morgan Mine
site and enabled a site-wide assessment of contaminant loads to groundwater in the Dee River system
under baseflow conditions. Sulphate (SO4), aluminium (Al), copper (Cu), iron (Fe) and zinc (Zn) are the
principal COCs at the Mount Morgan Mine site. COC loads generated by mine waste units, removed by
the seepage interception system and ultimately bypassing the seepage interception system to reach
the Dee River system were estimated by assigning representative seepage and/or groundwater quality
data to simulated recharges and flows from the groundwater flow model.
5.7. Ecology
Previous EA amendment applications submitted to DETSI over the years have presented desktop
information obtained from Protected Matters Search Reports and MSES search reports. As the Upper
Mundic Gully TSF footprint was mapped as intersecting mapped high risk areas for protected flora,
there was sufficient justification to undertake detailed ecological assessments to support this
amendment application with reference to the following guidance material:
• Terrestrial Vertebrate Fauna Survey Guidelines for Queensland;
• Flora Survey Guidelines – Protected Plants; and
• Methodology for surveying and mapping regional ecosystems and vegetation communities in
Queensland.
5.7.1. Desktop Assessment
A comprehensive desktop assessment was undertaken on the 10 February 2025 to identify potential
environmental values, constraints, and potential impacts within the Project area to enhance
understanding of the ecology of the area and its relationship to and connectivity with the surrounding
landscape. The desktop assessment results are discussed in Section 3 of GHD’s Ecological
assessment report (Appendix E). An additional updated desktop assessment was conducted by WTS
in the fauna survey report in September 2025 and the information sources used are summarised in
Table 43 and the results of the assessment are discussed in Section 3 of WTS’s Fauna Survey Report
127
Wulguru Technical Services Pty Ltd – Supporting Information to Amend an Environmental Authority
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