Item
Description
Information Requested
Response
Corresponding Sections
c) Steady-state and transient calibration results (with sufficient monitoring points surrounding the proposed UGM TSF) d) An operational scenario which reflects the proposed design of the UGM TSF (including expected foundation conditions and any other design elements that could influence the impact to groundwater) e) Particle tracking around the perimeter for the proposed UGM TSF to assess potential pathways. f) An assessment of risk to groundwater from the UGM TSF. g) Conduct and submit contaminant transport modelling to predict the movement of potential contaminants from the UGM TSF through the groundwater system. The report to be provided must include : i. Predictions of contaminant concentrations at potential receptors over time and at closure. ii. Details of the modelling approach, assumptions, and parameters used, such as hydraulic conductivity, porosity, and seepage rates. iii. Estimated seepage rates considering the high liquid content of the tailings slurry, the permeability of the tailings material and the underlying geology. iv. Sensitivity analyses to evaluate how changes in liquid content (i.e., due to rainfall or evaporation, and the intention to store water on the facility under extreme climatic events) could affect contaminant transport) h) Sensitivity and uncertainty modelling to provide an indication of the potential risk to groundwater receptors. i) Closure modelling.
a) – i) SLR proposes a phased approach to update the groundwater model to support the EA amendment to include the Upper Mundic TSF. The first phase involves updating the site- wide groundwater flow model developed by RGC (2011) and supporting conceptual model to better understand local groundwater conditions in the Upper Mundic valley and the adjacent catchments that could be affected by the construction of the Upper Mundic TSF (e.g. Spring Creek and Patty Creek). The second phase of modelling would involve the development of a solute transport model to simulate the transport of selected constituents in groundwater within the Mount Morgan Mine Site and provide simulated contaminant loads to the Dee River during the process of reprocessing tailings and post- rehabilitation. Further details are provided in the supporting information request .
Groundwater dependent ecosystems (GDEs)
Provide revised application material which:
A GDE impact assessment was undertaken in accordance with the EIS information Guideline and the supporting information has been updated that describes this assessment in more detail. a) The application has been updated to provide information relating to the spatial extent of impact from the proposed activity on mapped GDEs b) A ground truthing field assessment undertaken in accordance with the guidelines. The results of the survey have been included in the updated information. Considering the conceptual site model where groundwater was encountered at 110m below ground within UMG TSF footprint, the outcome of the assessments was that there are no GDE receptors that could be potentially impacted by TSF construction or operation. c) As the ground truthing did not indicate potential impacts to GDEs, the formulation of additional avoidance and mitigation measures above what is already proposed was not warranted d) A revised CCA has been included in the application
a) Section 6.7.5 b) Section 6.7.5 c) NA d) Appendix C
There is moderate potential terrestrial GDEs and potential GDE aquifers mapped within and around the proposed UGM TSF. Field surveys have not been undertaken to verify the mapped information and the potential risks and impacts via changes in groundwater levels and quality has not been detailed. It is stated, the affected terrestrial GDEs are upslope of the seepage flow direction, however, seepage pathways from the facility have not been field verified or demonstrated.
a) Determines the spatial extent of impact from the proposed activity on mapped GDEs. b) Confirms that mapped GDEs within and surrounding the proposed activity (extent of impact zone), have been ground truthed. In the absence of ground truthed information, the application assessment in relation to consideration of the significance of impacts to the receiving environment will assume that mapped GDEs are present (based on the current mapping available). c) Based on the information developed in relation to item (b), provide: i. The baseline conditions of all GDEs that have the potential to be impacted by the proposed amendment, or otherwise indirectly impacted. ii. A description of any potential risks and impacts to all GDEs to be impacted or likely to be impacted by the proposed activity. This must include potential changes to groundwater level and quality, including the expected locality and extent of the groundwater level and quality changes. iii. Proposed management and monitoring strategies and/or program to detect potential impact on GDEs and any corrective action(s) if impacts are detected. iv. Incorporate this information into the groundwater model accordingly. d) Revise the consequence category assessment with consideration of the information requested above. Please consider relevant guidance material to determine and assess impacts to GDEs, including the EIS Information Guideline (2024)
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ISO 9001 • ISO 14001 • ISO 45001
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