Notice
Information request
should be provided in the same format as Schedule A1 (Authorised mining activities and locations) of the EA.
4
Western dump
Provide revised application material which:
The UGM TSF is proposed to be built over a portion of the existing western dump. It is acknowledged in the application that the western dump is likely contributing to acid rock drainage (ARD), however, this has not been confirmed via submission of site data or investigations. It is stated the exposed face of the western dump will be sealed, further reducing potential ARD seepage. However, no information is presented regarding the material or methods to be utilised to support the assertion this will reduce potential ARD. The application material suggests construction of the UGM TSF will involve reshaping of the western dump, however, there is no understanding regarding the extent of the proposed reshaping or its implications for areas of the dump that fall outside of the proposed UGM TSF. No information is presented confirming the suitability of constructing the foundation and embankment over the existing dump and the potential risks of exacerbation of the suggested ARD.
a) Details the proposed reshaping requirements necessary for the western dump, the potential implications for the entire western dump and the proposed management measures to avoid environmental harm caused by this action, where necessary. b) Details the risks and management measures required to ensure ARD isn’t exacerbated via the construction of the UGM TSF embankment over the existing western dump. Detail how it will be demonstrated that ARD isn’t exacerbated and how it will be determined and demonstrated potential impacts from the UGM TSF will be differentiated from the western dump. c) Confirms the suitability of the building the foundation and embankment of the UGM TSF over the existing western dump. This should involve a discussion of the findings of the relevant geotechnical investigations as recommended in the UGM TSF Design Report (WSP, 2025) 2 .
5
Dam 8
Provide revised application material which:
Dam 8 is not authorised under the EA however it is stated Heritage Minerals Pty Ltd use water from Dam 8 for construction and processing activities. This is further supported by the water balance technical memorandum (WBM Memo) (GHD, 2025) 3 which includes provisions for Dam 8 water transfers to the plant at 0.4 megalitres per day (ML/d) in Stages 2 and 4 of the project’s operation. By way of sealing the tunnel to Dam 8 via the
a) Detail how water contributions to Dam 8 may be impacted via the construction of the UGM TSF and how this will be managed in order to ensure activities undertaken by Heritage Minerals Pty Ltd and the DNRMMRRD are not affected. b) Describe the environmental values of Dam 8 and the potential implications in the event seepage flow pathways from the UGM
2 WSP, Upper Mundic Gully TSF Concept Design to RL 390 m, October 2025
3 GHD, Heritage Minerals EA Amendment Application – Updates to Water Balance Model July 2025 (Final), 1 October 2025
Page 4 of 20 • ESR/2016/3447 • Version 4.02 • Last reviewed: 29 OCT 2025
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