Data as at 14 September 2026 · from the Queensland EP Act public register
P-PRCP-100732451 · WANDOAN HOLDINGS PTY LIMITED
PRC plan P-PRCP-100732451 for WANDOAN HOLDINGS PTY LIMITED (EPML00297613), coal. 1 applications, including information requests and replies.
- Environmental authority
- EPML00297613
- Holders
- WANDOAN HOLDINGS PTY LIMITED; SCAP WANDOAN PTY LTD
- Tenures
- ML50229; ML50230; ML50231
- Plan versions
- P-PRCP-100732451 (effective 2026-06-08)
- Current schedule final milestone
- not read
- Areas in current schedule
- 7 · 17,006 ha
Schedule versions
| Version | Effective | Final milestone | Areas | Document |
|---|---|---|---|---|
| 1 | 2026-06-08 | – | 7 | Schedule PDF |
| 2 (current) | 2026-06-08 | – | 7 | Schedule PDF |
Rehabilitation and improvement areas
From the current schedule's tables. Land use categories are keyword groupings; the schedule's wording is shown beneath.
| Area | Activities | Hectares | Post-mining land use | First milestone | Page |
|---|---|---|---|---|---|
| RA1rehabilitation | Pits including Lowwalls and Overburden Emplacements | 8383 | GrazingGrazing | 20XX + 2 | 17 |
| RA2rehabilitation | Infrastructure | 1009 | GrazingGrazing | 20XX + 4 | 19 |
| RA3rehabilitation | Decommissioned haul roads and ROM pads | 101 | GrazingGrazing | 20XX + 70 | 21 |
| RA4rehabilitation | Retained Haul Roads | 548 | GrazingGrazing | 20XX + 76 | 22 |
| RA5rehabilitation | Water Infrastructure | 126 | GrazingGrazing | 20XX + 76 | 23 |
| RA6rehabilitation | Highwalls and End walls including weathered zone | 212 | Native ecosystemNative Bushland | 20XX + 26 | 24 |
| RA7rehabilitation | Exploration and Ancillary Activities | 6627 | GrazingGrazing | 20XX + 102 | 26 |
Application A-PRCP-NEW-100732384
- First information request
- 2025-05-30
- Response due
- 2025-12-05
- Plan effective
- 2026-06-08
- Register
- Application record
10 documents on the register
- A-PRCP-NEW-100732384_ApplicationDocuments_Attachment_01 Other
- A-PRCP-NEW-100732384_ApplicationDocuments_Attachment_02 Other
- A-PRCP-NEW-100732384_ApplicationDocuments_Attachment_03 Other
- A-PRCP-NEW-100732384_InformationRequest_01 Information request
- A-PRCP-NEW-100732384_InformationResponse Information response
- A-PRCP-NEW-100732384_InformationResponse_Attachment_01 Response attachment
- A-PRCP-NEW-100732384_InformationResponse_Attachment_02 Response attachment
- A-PRCP-NEW-100732384_InformationResponse_Attachment_03 Response attachment
- A-PRCP-NEW-100732384_InformationResponse_Attachment_04 Response attachment
- A-PRCP-NEW-100732384_InformationResponse_Attachment_05 Response attachment
Information request: 46 items
Department foundThe final site design included in the proposed Progressive Rehabilitation and Closure Plan (PRCP) does not align with the disturbance extent authorised under the current environmental authority (EA) for the Wandoan coal project. A PRCP must include a rehabilitation area/ management area for all disturbance authorised under the EA. As per section 4.1 of PRCP Guideline, “Only areas of disturbance need to be included in the rehabilitation areas/improvement areas.”’ Wandoan PRCP can be considered a greenfield site under Scenario 2 as outlined in the following information sheet - https://www.detsi.qld.gov.au/policies?a=272936:policy registry/rs-is- _ exploration-greenfield- prcp.pdfhttps://www.detsi.qld.gov.au/policies?a=272936:policy registry/rs- _ is-exploration-greenfield-prcp.pdf If Glencore propose to proceed with a reduced disturbance footprint in the PRCP as compared to the EA, if and when the PRCP schedule is approved, the PRCP schedule and EA must both contain conditions limiting the disturbance area to that detailed within the approved PRCP Schedule until an approved PRCP existed for the whole authorised EA area. If proceeding with this approach, this must be made clear in the updated PRC Plan and Schedule provided in response to this information request. Rehabilitation Area (RA6) includes 4,844ha of EA approved disturbance not scheduled to be disturbed and only final rehabilitation milestones (RMs) i.e., achievement of Post Mining Land Use (PMLU) to stable condition (RM8 and RM10) apply.
Asked forTo align the approved disturbance between EA and PRCP, please provide updated PRC plan addressing RA6 disturbance and milestones, including but not limited to: (a) Change description of RA6 to “ancillary disturbance”; (b) Allocate relevant RMs (and not just one final RM); (c) Push completion dates to end of PRCP schedule; and (d) Where relevant, include RA6 in all rehabilitation planning and modelling (i.e., flood, groundwater, erosion assessment).
Applicant repliedRehabilitation areas (RAs) within the PRCP and PRCP Schedule have been updated to align the approved disturbance footprint between the Wandoan Coal Project (WCP) EA and PRCP. RA6 has now become RA7. a) Table 9-1 of the PRCP has been updated to describe RA6 as “Highwalls and end walls including weathered zone” with a total area of 212 ha and a PMLU of Native Bushland. Areas that are not scheduled to be disturbed have been allocated to RA7, with a PMLU of grazing, and an area of 4,844 ha. RA7 has been renamed to exploration and ancillary activities. Figure 9-2 has been updated to reflect these changes to RA6 and RA7. b) Relevant RMs have been included for RA7 in the PRCP Schedule. c) Rehabilitation available date for RA7 begins at the latest final completion date of the other RAs. d) It is not relevant to include RA7 in technical study assessments because the area is planned for proposed exploration and ancillary activities only. The total area for RA7 has been updated and associated figures and tables within the PRCP have been aligned (Figure 5-3, Figure 3-1, Figure 9-1 and Figure 9-2 and Table 9-1).
Department foundThe Table included in Appendix 2 below compares the rehabilitation outcomes, land class suitability (DME 1995) for grazing outcome, and slopes of disturbance domains as authorised under the current EA (a land outcome document) and the proposed PRCP. Review of this table indicates the slopes for some domains are proposed to be steeper than that approved under the current EA for recontoured spoil and waste rock dumps (18% compared with proposed slopes up to 22%), and roads and tracks (10% compared with <15%). Landform slope can impact the stability and achievement of final land use. As such, further information is required to justify the final landform can achieve the approved outcomes.
Asked forProvide a revised PRC plan that clarifies why the slopes approved under the EA cannot be achieved, and justification that the steeper slopes can support a grazing outcome.
Applicant repliedThis comment relates to Table 5-17 in the PRCP. The presentation of information in this table has been updated. The slopes proposed in the PRCP are not steeper than those authorised by the EA. However, the presentation of proposed final landform slopes as a range appears to have led to a misinterpretation. For clarity, proposed maximum slopes for each disturbance type have been provided. In addition, Table 5-2 and Section 5.1 of the PRCP has been revised to further clarify the disturbance types of WCP final landform to achieve the EA approved slopes. Majority of the landform (97.58 %) has a slope that is less than 18 % and aligns with the EA approved slope gradient and PMLU. Lowwalls make up a total of 1.16 % and align with the EA approved slope gradient of less than 100 % and the EA approved PMLU. Highwalls account for 1.24 % of the final landform and meet the EA slope requirements and EA approved PMLU. Tables 5-1 and 6-1 of the PRCP have been updated to include the competent rock highwall max slope as per the WCP final landform. Table 5-1 also includes the EA approved max slope of 214 % for the highwalls to demonstrate the slopes remain in accordance with the EA approval.
Department foundSection 5.1.2 of PRC plan states that during construction of the landform, final slope and bench design including any temporary erosion control structures will be considered. The PRC plan lacks details about erosion control structures which have high failure probability, and more information is required to demonstrate that these structures can be expected to remain stable in a post-closure context. Milestone criteria will be required to demonstrate stability, including a requirement for a third-party AQP to certify that the structures can be expected to remain stable in the long term, with consideration given to ongoing performance, maintenance requirements, and residual risk post- closure.
Asked forProvide an updated Rehabilitation Planning Part that: (a) Clearly determines the rehabilitation methodology to achieve final landform design, including but not limited to, the use of engineered structures; (b) Provides further information to demonstrate that engineered structures will achieve stable condition; and (c) SMART milestone criteria which demonstrate stability of the final landform.
Applicant replieda) & b) WCP is a greenfield site and the timing regarding the commencement of mining operations is yet to be confirmed and as such the final landform design is conceptual. The landform construction details provided in Section 5.1.2 of the PRCP are sufficient. If WCP becomes operational, the preferred construction methods will be refined and more detailed landform designs provided. Updates to Section 5.1.2 of the PRCP have not been made at this time. c) RM9.9 has been drafted to ensure that engineered structures that remain in the final landform (e.g., rock drains), must be certified by an AQP as stable and can be expected to remain stable and functional.
Department foundAs per Figure 5-2 of the plan, the safety bund is proposed to be placed at the top of the slope beyond the weathered zone (figure 5-2 copied below for reference). As per section 5.7.2.3, modelled highwall stability exceeds the departments expectation of a minimum factor of safety of 1.5. As per table 5-20 the FoS has been modelled at either the upper slope or the overall slope. To demonstrate geotechnical stability of 8 free draining voids, only 1 void named Leichhardt was considered with slopes of 40 or 60 degrees, not slopes up to 214% as proposed. Further justification is required to ensure that Liechhardt is representative of all free draining voids to confirm they will achieve geotechnical stability. The PRC plan also lacks details about safety gates/fence outside the safety bund.
Asked forProvide a revised PRC plan that details the: (a) FoS of the highwall above the unweathered competent rock and above the weathered highwall slope; (b) Justification that the stability analyses results for Leichardt South pit are applicable to the other 7 pits that will have a highwall remaining post-closure (but be free draining with no depression); (c) Based on information provided from (a) and (b), include commitment in the RM criteria of highwalls and spoil dumps achieving an FoS ≥ 1.5; and (d) Where relevant, revise the location of the safety bund for each highwall to demonstrate sustainable PMLU and long-term stability or clarify if access gates are required.
Applicant replieda) This information was provided in the original PRCP submission. Section 5.7.2.3 and Appendix M of the PRCP provides the critical FoS areas for the highwalls that represent the three highest and steepest highwalls of the thirteen highwalls present in the final landform. The critical FoS areas represent the areas where the FoS is lowest, with areas outside this zone having a higher FoS, and gives consideration to the weathered and unweathered highwall slope. The critical FoS for the three highest and steepest highwall slopes all exceed a FoS of 3. Table 5-1 of the PRCP has been updated to show the competent highwall slopes proposed in the landform are well within the highwall slopes authorised under the EA. b) The geotechnical stability of the Leichhardt Pit highwall was specifically assessed as it is intended to be a long-term (75 years) water storage for the site. A major consideration for void geotechnical stability is the subsequent emptying of the void especially after it has been used as a water storage. The stability analyses considered no water in the void as this is the most critical case. A minimum critical FoS of 2.3 is achieved for the Leichhardt Pit highwall. It is not stated in the PRCP that this assessment is applicable to the four (not seven) highwalls that remain in free draining reprofiled voids. c) RM3 has a milestone regarding FoS. Highwalls are to achieve a minimum FoS of 1.2 with the safety bund being located at a minimum FoS of 1.5. These minimum requirements are all achieved by the proposed final landform. d) Figure 5-2 has been updated to include the minimum FoS >1.5 at the safety bund. All highwalls analysed exceed this minimum design standard of FoS >1.5 for safety bunds which will be located at the backside of the regraded weathered zone.
Department foundTable 6.1 of Appendix I shows depth of reprofiled void depressions as difference between voids base and max water level. This should be maximum water depth and not maximum void depth.
Asked forFor reprofiled void depressions, update Table 6.1 of Appendix I to: (a) Rename the column titled as “Maximum depth (m)” to “Maximum Water depth (m)”; and (b) Clarify maximum void depth.
Applicant repliedTable 5-6 of the PRCP and Table 6.1 of Appendix J of the PRCP has been updated to differentiate between maximum void and water depths with definitions added to the notes.
Applicant repliedTable 6.1 has been updated to differentiate between maximum void and water depths with definitions added to the notes.
Department foundSection 2.3.7 of PRC plan identifies the relevant waterways and their environmental values. No receiving environment water quality data has been provided. The PRCP guideline section 3.1 requires the EA holder to provide baseline information with respect to site hydrology and fluvial networks. Similarly, groundwater quality data has not been provided. Background surface and groundwater quality data is important as it helps to determine the water quality limits, suitability of monitoring locations to demonstrate the stability and non-polluting state of the final rehabilitated landform.
Asked for(a) Provide an updated Rehabilitation Planning Part that includes background/baseline receiving environment water quality monitoring data and groundwater quality data. (b) Please provide surface and groundwater data (separately) in one of the attached spreadsheets: • Attachment 1 Data Blank 1; or _ _ _ • Attachment 2 Data Blank 2. _ _ _
Applicant replieda) As per Section 3.1 of the PRCP guidelines, the appropriate baseline information has been provided and is described in Section 2.3.7 of the PRCP. b) Surface and groundwater data has been provided as part of the PRCP IR Response package.
Department foundSection 4.6.11 states: “Local groundwater flow conditions may be different from regional flow conditions with potential steeper gradients and increased velocities in response to hydraulic stresses such as groundwater abstraction.” It is noted that no groundwater contours are provided based on observed groundwater levels at the project site to support any discussion about groundwater flows. This is required as a basis for the conceptualisation of the groundwater system and to compare with simulated groundwater contours from the numerical groundwater model.
Asked forProvide groundwater level elevation contours for the major geologic units based on the observed groundwater levels at the project site to provide confidence in the modelled groundwater elevation contours and to understand the current groundwater flow directions.
Applicant repliedSection 4.6.11 (in version 1 of the PRCP) stated that: “Local groundwater flow conditions may be different from regional flow conditions with potential steeper gradients and increased velocities in response to hydraulic stresses such as groundwater abstraction.” The statement was included in the regional groundwater flow discussion to highlight that local conditions may be different. Responses at the local scale are discussed in Section 4.6.4 of Appendix H. Inferred groundwater table contours for 2022 are provided and discussed in Section 4.6.2 of Appendix H. The groundwater contours indicate that groundwater elevations are highest to the south-southeast of WCP. The general inferred groundwater flow is towards the north and east. Directly within WCP the flow is from the southwest to northeast. Limited localised influence of CSG activities is evident in the water table contours. Numerical model generated contours for the calibration period are included in Section 5.3 of Appendix H extracted from the numerical groundwater model for the start and end of the calibration period (1995 and 2022). The 2022 contours show that the general flow directions are similar to the inferred groundwater contours, with the model output providing greater resolution. This increased detail reflects the influence of the spatial distribution of monitoring data on the inferred contours.
Applicant replied▪ The statement referenced as the issue is included in the regional groundwater flow discussion to highlight that local conditions may be different. Responses at the local scale are discussed in Section 4.6.4. ▪ Inferred groundwater table contours for 2022 are provided and discussed in Section 4.6.2. The groundwater contours indicate that groundwater elevations are highest to the south-southeast of the Project. The general inferred groundwater flow is towards the north and east. Directly within the Project area the flow is from the southwest to northeast. Limited localised influence of CSG activities is evident in the water table contours. ▪ Numerical model generated contours for the calibration period are included in Section 5.3. extracted from the numerical groundwater model for the start and end of the calibration period (1995 and 2022). The 2022 contours show that the general flow directions are similar to the inferred groundwater contours, with increased resolution associated with the model output as the inferred contours are largely controlled by the spatial distribution of monitoring data.
Department foundSection 4.6.2 states: “GCAA monitors a network of bores within the Project area on behalf of the Proponent, with additional bores installed in late- 2023/24 to supplement the existing network.” Based on Table I-1 in Appendix 1 it appears that 20 bores were drilled in November/ December 2023. It is noted that the numerical model transient calibration period finishes in December 2022 indicating that water levels from the new bores were not used in the calibration of that model. Figure IV-3.2 (Transient Calibration Points) appears to confirm this. Additionally, strata details from the new bores appear likely to be unavailable for use in developing model layers. It is not clear if any information from the new bores has been used in any way to support the groundwater report. This information should be made clear to understand what data was available to support the groundwater assessment.
Asked forProvide advice as to whether the new bores drilled in November/ December 2023 were used in any way to support the groundwater report. If so, how the information from these bores was used.
Applicant repliedClarification is included in Appendix IV and Section 4.6.3 of Appendix H. An additional 20 bores were installed at the end of 2023, early 2024 to supplement the existing network. The first available data from the additional monitoring bores was available in early 2024 and the original PRCP was submitted in September 2024. Due to the timing of the drilling program, and time frame for the development of numerical model to support the PRCP, the data from the additional monitoring bores was not available for incorporation into the numerical model. Work on the numerical model commenced in early 2023. Information from the new bores is recommended to be incorporated in any future numerical model updates (as recommended in Section 6.4 of Appendix G).
Applicant replied▪ Clarification is included in Appendix IV and Section 4.6.3. ▪ An additional 20 bores were installed at the end of 2023, early 2024 to supplement the existing network. ▪ The first available data from the additional monitoring bores was available in early 2024. Due to the timing of the drilling program, and time frame for the development of numerical model to support the PRCP, the data from the additional monitoring bores was not available for incorporation into the numerical model. Work on the numerical model commenced in early 2023. ▪ Information from the new bores is recommended to be incorporated in any future numerical model updates (as recommended in Section 6.4 of the main report).
Department foundFigure 4.7 appears to indicate a large number of monitoring bores drilled on the eastern part of the project site but very few on the western part of the site. There is no discussion in the report as to why this spread of monitoring bores has been adopted. Provide discussion as to: (a) Why the majority of monitoring bores are located on the eastern side of the project. (b) How has this impacted the assessment of groundwater conditions on the western part of the site.
Applicant repliedClarification is included in Section 4.6.3 of Appendix H. An additional 20 bores were installed at the end of 2023, early 2024 to supplement the existing network. The additional monitoring bores were installed on the eastern side of WCP as the first mining is planned to commence in the east, with later mining planned to occur in the west. Additional monitoring on the western side of WCP will be planned, designed and installed as mining progresses.
Applicant replied▪ Clarification is included in Section 4.6.3. ▪ An additional 20 bores were installed at the end of 2023, early 2024 to supplement the existing network. The additional monitoring bores were installed on the eastern side of the Project area as the first mining is planned to commence in the east, with later mining planned to occur in the west. ▪ Additional monitoring on the western side of the Project area will be planned and installed as mining progresses. ▪ Existing monitoring bores and public domain information were used for the western side of the Project area. ▪ Refer to Section 6.4 regarding adaptive management approach through operations and closure.
Department foundSection 4.6.3 Groundwater Data states “however, monitoring to the south of the Project shows a decline in groundwater levels1 of ~150 m (Appendix II).” A footnote to this comment states: Note that data has been extracted from the GWDB and cannot be verified for accuracy. Some data is considered unreliable. It is noted that some data provided in the report appears to be referenced from Vibrating Wire Piezometers (VWPs). Is this the data that is considered unreliable? DETSI has concerns about the quality of data that is provided from some VWPs across a number of mining sites. It is unclear if any VWP data used in developing this groundwater assessment been verified. Provide an update rehabilitation planning part that details: (a) Whether the unreliable data referenced was VWP data. (b) How any VWP data that was used in the groundwater assessment was verified for accuracy.
Applicant repliedThe report has been updated to provide clarification in Section 4.6.3 of Appendix H. This comment relates to the groundwater database (GWDB) data, in general, and that it is not possible to verify the accuracy of data contained in the database. The professional judgement of an AQP was used to review and conduct QA/QC of the externally sourced data (as well as GCAA’s own data) that was used to develop the hydrogeological conceptualisation and understanding of the system, as well as the data used for numerical modelling. Where appropriate the data was excluded from the assessment. QA/QC processes include visual review of the monitoring data and comparison to other monitoring data (such as GCAA data or data used in the Surat CMA UWIR) which has a higher confidence, removal of outlier values, identification of values which may have telemetry issues, or have not been converted correctly.
Applicant replied▪ The report has been updated to provide clarification in Section 4.6.3. ▪ The comment is related to groundwater database (GWDB) data, in general (not just VWP data), and that it is not possible to verify the accuracy of data contained in the database. ▪ Professional judgement was used to review and QA/QC the externally sourced data (as well as Glencore’s own data) that was used to develop the hydrogeological conceptualisation and understanding of the system, as well as the data used for numerical modelling. Where appropriate the data was excluded from the assessment. ▪ QA/QC processes include visual review of the monitoring data and comparison to other monitoring data (such as Glencore data or data used in the Surat CMA UWIR) which has a higher confidence, removal of outlier values, identification of values which may have telemetry issues, or have not been converted correctly.
Department foundThe groundwater report provides no modelled groundwater elevation contours for the major geologic units at the start of the transient calibration in 1995 or at 2022 (end of calibration). These contours would provide the simulated impact of CSG activities during this period. The 2022 simulated groundwater elevation contours should be compared to the groundwater elevation contours developed based on observed data to determine how well the model is simulating actual groundwater level conditions and observed groundwater flow directions.
Asked forProvide modelled groundwater elevation contours for the start and end of the model calibration period to demonstrate model predicted impacts of CSG on groundwater levels, and to provide a comparison of modelled groundwater elevation contours with groundwater elevation contours developed using observed groundwater data. The latter will provide confidence in the groundwater modelling.
Applicant repliedSimulated groundwater table elevation contours are provided and discussed in Section 5.3 of Appendix H. Comparison of the groundwater table contours between 1995 and 2022 shows that about 30 to 40 m drawdown occurred in the southwest of the model domain during this period, which is attributed to CSG development in the area. See also Item 7 response.
Applicant replied▪ Simulated groundwater table elevation contours are provided and discussed in Section 5.3. ▪ See item 7 response. ▪ Comparison of the groundwater table contours between 1995 and 2022 shows that about 30 to 40 m drawdown occurred in the southwest of the model domain during this period, which is attributed to CSG development in the area.
Department foundSection 6.1 states “No groundwater-driven residual pit lakes are predicted in the base case simulations, which uses the average annual rainfall for the modelled recharge. However, there is a residual risk that during very wet years, that ephemeral water bodies could rise in these areas. Since progressive backfill and rehabilitation will be undertaken, an improved understanding of these risks should be developed during operations. Shallow groundwater is predicted in proximity of several backfilled open cut areas, generally in areas where the overburden emplacements are located close to the watercourses, where there is lower topography and there is localised mounding associated with the overburden emplacements.” It is noted that post mining groundwater levels are predicted to be close to the surface in some areas, as little as 1m is stated, and there is potential for higher groundwater levels in those wetter years which have not been modelled. It is stated that as progressive backfill and rehabilitation will be undertaken an improved understanding of these risks should be developed, but no discussion of what management options might be adopted should these risks be realised. There is no discussion of how future updated groundwater modelling will incorporate additional information that is acquired during mining and early backfilling operations and how this might be utilised in any alterations to the final landform. Given the uncertainties associated with final post mining groundwater levels and the residual risks associated with groundwater rising above ground level and into some depressions, provide an updated rehabilitation planning part that includes additional information on what steps will be taken in the future in regard to updated groundwater modelling and potential adjustment of final landform design.
Applicant repliedSection 6.4 of Appendix H provides additional information regarding potential future considerations. This information further supports the PRCP predictions as well as refinement of the hydrogeological understanding during operations. Baseline groundwater level and chemistry monitoring will commence two years prior to the construction of operations. Additional shallow monitoring to the west of WCP, between the mining areas and the watercourses is recommended to be installed in a staged approach (at least two years before the open cut pit is to be mined). Coupled seasonal surface water sampling is also recommended to understand baseline water quality within the watercourses and monitoring will commence two years prior to the construction of operations. The numerical model groundwater predictions (including post- closure scenarios), Will be updated and refined after the first five years of mining. It is recommended that the update include calibration to dewatering volumes and monitoring responses to mining activities. This will enhance confidence in the numerical model and improve understanding of the groundwater system response. Collection of site-specific hydraulic properties, through pumping tests, will also provide further information to verify the model predictions and system response. The sensitivity scenarios on spoil recharge, included in Appendix IV of Appendix H, highlighted that in the majority of areas the lower recharge rate results in a lower water table elevation at the spoils. Once spoil placement commences, site- specific testing to obtain estimates of spoil recharge is recommended. The site-specific estimates will then assist with further refinement of the numerical model predictions for post-closure and further understanding of the risks to the receptors. Based on the monitoring and refined model results, WCP will progressively review management and mitigation measures for closure. Assessment of potential options is only recommended to be considered once the above monitoring and model refinement is undertaken (after the first five years of mining operations) and an improved understanding of the system response is available. The rehabilitation planning part has not been updated.
Applicant replied▪ Section 6.4 provides this information: To further support the PRCP predictions as well as refinement of the hydrogeological understanding during operations, monitoring is recommended to continue under the EA framework, with baseline groundwater level and chemistry monitoring for at least two years prior to commencement of operations. Additional shallow monitoring to the west of the Project, between the mining areas and the watercourses is recommended to be installed in a staged approach (at least two years before the open cut pit is to be mined). Coupled seasonal surface water sampling is also recommended to understand baseline water quality within the watercourses. Update and refine the numerical model groundwater predictions (including post-closure scenarios), within the first five years of the operational period. The update is recommended to include calibration to the dewatering volumes and monitoring response to mining, which will assist in increasing the numerical model confidence and understanding of the groundwater system response. Collection of site-specific hydraulic properties, through pumping tests, will also provide further information to verify the model predictions and system response. The sensitivity scenarios on spoil recharge, included in Appendix IV, highlighted that in the majority of areas the lower recharge rate results in a lower water table elevation at the spoils. Once spoil placement commences, site-specific testing to obtain estimates of spoil recharge is recommended. The site-specific estimates will then assist with further refinement of the numerical model predictions for post-closure and further understanding of the risks to the receptors. Based on the monitoring and refined model results, progressively review management and mitigation measures for closure. Assessment of potential options is only recommended to be considered once the above monitoring and model refinement is undertaken (after five years of mining) and an improved understanding of the system response is available.
Department foundSection 6.1.2 of Flow Direction and Velocity and Table 6.1 appear to indicate groundwater flow from some of the backfilled pit spoil areas towards nearby watercourses. It is stated that: Review Sections 6.2, 7 and Appendix V and provide clarification as to whether groundwater from the backfilled areas is predicted to drain into nearby creeks and/or contribute to alluvial groundwater. Provide advice on how future monitoring of water quality in spoil areas will be conducted and the results incorporated into future decision making relating to final landform Groundwater levels are not predicted to daylight (i.e. express above ground surface) in the base case groundwater model prediction, which uses the average annual rainfall for recharge. Section 6.2 appears to indicate that the anticipated water quality within the spoil material will not pose a significant risk to the quality of surface and groundwater resources in the vicinity of the Project. However, despite this statement it is not clear if groundwater is predicted to drain into the creek beds that have been identified as receptors. For example, in periods immediately following high rainfall and high recharge in the alluvium, there may be potential for movement of alluvial groundwater back into the watercourse when stream flows finish. In the case of Woleebee North and Woleebee North Sat, Appendix V, Figures V-10 and V-11 appear to indicate that the final groundwater level will be above bed level in Woleebee Creek. But in ‘section 7 Conclusion’, it is stated ‘Groundwater is not predicted to express within the creeks’. This statement appears to conflict with Figures V-10 and V-11 referenced above. This issue should be clarified to confirm the final landform can achieve non- polluting.
Asked formanagement to minimise movement of any poor-quality groundwater towards watercourses.
Applicant repliedClarification is included in Section 6 of Appendix H: Groundwater levels are not predicted to daylight (i.e. express above ground surface) in the base case groundwater model prediction, which uses the average annual rainfall for recharge. There are some areas, however where the recovered water table is predicted to be higher than the base of the alluvium unit. The statement in Section 7 of Appendix H refers to the daylight of water above ground surface, consistent with the statement in Section 6 of Appendix H: Groundwater is not predicted to express within the creeks. For the alluvium and watercourses, the range of increased salinity is not expected to be significant as the seepage and run-off water chemistry is of low to moderate salinity, inferred flow rates of seepage are low and any potential evapo- concentration that could occur would be expected to be seasonally diluted by fresh rainfall recharge and/or run-off. The EC values predicted from the run-off and seepage are also expected to be within a similar magnitude to the natural water quality measured in the alluvium. See Item 12 response for adaptive management and monitoring discussion which is included in Section 6.4 of Appendix G. Additional monitoring should be considered once operations commence and there is additional information available to update the numerical groundwater model predictions.
Applicant replied▪ Clarification is included in Section 6: Groundwater levels are not predicted to daylight (i.e. express above ground surface) in the base case groundwater model prediction, which uses the average annual rainfall for recharge. There are some areas, however where the recovered water table is predicted to be higher than the base of the alluvium unit. ▪ The statement in Section 7 refers to the daylight of water above ground surface, consistent with the statement in Section 6: Groundwater is not predicted to express within the creeks. For the alluvium and watercourses, the range of increased salinity is not expected to be significant as the seepage and run-off water chemistry is of low to moderate salinity, inferred flow rates of seepage are low and any potential evapoconcentration that could occur would be expected to be seasonally diluted by fresh rainfall recharge and/or run-off. The EC values predicted from the run-off and seepage are also expected to be within a similar magnitude natural water quality measured in the alluvium. See Item 12 for adaptive management and monitoring discussion which is included in Section 6.4. Additional monitoring should be considered once operations commence and there is additional information available to update the numerical groundwater model predictions.
Department foundIn figure I1-3.14 the lower bounds for recharge rates of 1x 10-8m/day (0.0036mm/yr) for all aquifers and the calibrated recharge rates for non- alluvial aquifers appear very low. The calibrated recharge rate for the Weathered Surat Basin being 4.49 x 10-7m/day (0.16mm/yr) and for the Springbok Sandstone being 3.56 x 10- 7m/day (0.13mm/yr). In comparison the lowest OGIA rates referenced in Section 4, Table 4.1 of this report were 4.3mm/yr for the Walloon Coal Measure and 3.2mm/yr for the Springbok Sandstone. These values are much higher than those being used in the Wandoan numerical model. No justification is provided for these low bounds and low calibrated recharge rates. Information should be supplied to demonstrate that recharge rates applied in the modelling are within realistic boundaries to provide confidence in the modelling.
Asked forProvide an updated rehabilitation planning part that includes additional information to support the lower bounds used for the calibration of recharge rates and the final calibrated recharge rates in the non-alluvial aquifers in Table I1-3.14.
Applicant repliedAdditional discussion is provided in Appendix IV-2.5 of Appendix H, clarifying the recharge values adopted in the numerical groundwater model. The calibration approach and calibrated recharge rates are consistent with the OGIA numerical groundwater modelled values (OGIA 2019*). *OGIA 2019. Underground Water Impact Report for the Surat Cumulative Management Area. State of Queensland, The Office of Groundwater Impact Assessment, Department of Natural Resources, Mines and Energy.
Applicant replied▪ Additional discussion is provided in Appendix IV-2.5, clarifying the recharge values adopted in the numerical groundwater model. ▪ The calibration approach and the calibrated recharge rates are consistent with the OGIA numerical groundwater modelled values (OGIA 2019).
Department foundVI-4.2.1 Life of Mine - Model Set-Up – Recharge to spoil This section states: Similarly, a reference recharge rate (10% of rainfall) and evapotranspiration rate (same as alluvium unit) was applied for the spoil sourced from Williams (2008). It is noted that Williams (2008) is identified as: Williams, David, J. 2008. ‘The Influence of Climate on Seepage from Mine Waste Storages During Deposition and Post-Closure’. Mine Closure 2008. Typically, where localised data is not available, model reports have referenced Mackie (2009), and a recharge rate of between 1 and 5.5% of rainfall to be used on the spoil. DETSI have reviewed Williams (2008) and it is not clear what part of this report has been referenced to support a spoil recharge rate of 10%. The recharge rate applied to the spoil in the latter stages of mining and post mining is potentially an important part of the water balance.
Asked forProvide additional advice as to how Williams (2008) supports the use of a recharge rate of 10% for the spoil in the numerical groundwater model. Provide advice as to why Williams (2008) was referenced in preference to Mackie (2009).
Applicant repliedFurther information is provided in Appendix IV-4.2.1 of Appendix G related to the recharge values adopted for the spoils. Additional modelling scenarios for 1 % and 5 % recharge scenarios are also included in Appendix IV of Appendix H, to consider the range of values quoted by DETSI. The sensitivity scenarios on spoil recharge, included in Appendix IV of Appendix H, highlighted that in the majority of areas the lower recharge rate results in a lower water table elevation at the spoils. Once spoil placement commences, site- specific testing to obtain estimates of spoil recharge is recommended. The site-specific estimates will then assist with further refinement of the numerical model predictions for post-closure and further understanding of the risks to the receptors.
Applicant replied▪ Further information is provided in Section IV-4.2.1 in Appendix IV related to the recharge values adopted for the spoils. ▪ Additional modelling scenarios for 1% and 5% recharge scenarios are also included in Appendix IV, to consider the range of values quoted by DETSI. ▪ The sensitivity scenarios on spoil recharge, included in Appendix IV, highlighted that in the majority of areas the lower recharge rate results in a lower water table elevation at the spoils. Once spoil placement commences, site-specific testing to obtain estimates of spoil recharge is recommended. The site-specific estimates will then assist with further refinement of the numerical model predictions for post-closure and further understanding of the risks to the receptors.
Department found16.1 Section 5.6.2 of PRC plan provides details about topsoil stockpile planning and placement. There is no mention of stockpile height that has direct relationship with soil health* and must be considered when planning for stockpiling. As per Mine Rehabilitation (industry.gov.au) standard topsoil stockpiles height is <2m and a greater height can result in significant deterioration of soil physicochemical and biological properties. This information is required to ensure that sufficient quality topsoil will be available for rehabilitation activities. * Fischer, A. M., Van Hamme, J. D., Gardner, W. C., & Fraser, L. H. (2022). Impacts from topsoil stockpile height on soil geochemical properties in two mining operations in British Columbia: implications for restoration practices. Mining, 2(2), 315-329. 16.2 Section 2.3.4.4 of PRC plan provides soil quality results. Soil pH and Exchangeable Sodium Percentage (ESP) results are from 2008. The sampling regime for waste characterisation must meet the best practise standards. One of such standards is to have temporally representative i.e., most recent data. Having knowledge of mine material properties as close to the landform construction as possible will ensure that each material is suitable both for its final placement in the landform, and for the target plant community to be re- established. For soil quality characteristics, other than pH and ESP, Appendix B provides latest results from 2024. However, a total of 11 soil samples from a maximum of 9 sampling sites (one bulk pit and 8 drill holes), all located within one mining lease (ML50230), were chosen. To meet the best practice standards, sampling regime must also be spatially representative with sample numbers sufficient to characterise all soils that would be disturbed and/or used in rehabilitation of the site. The rate of sampling should be like those used in precision agriculture which is around 1 test site per 5ha as long as the material is of a similar nature. 16.3 Section 4 of Appendix B states that, “selenium can have a concentration greater than the livestock drinking water value (ANZG, 2018) under ideal oxidising conditions.” It also states that, “Overall, dissolved metal/metalloid concentrations in surface runoff and seepage from the mine materials are unlikely to present a significant risk to surface and groundwater resources with the expectation that the material will be handled according to standard industry mine waste management practices.” To confirm the final landform will be stable and non-polluting, section 3.6.1 of PRCP Guideline requires the plan to “Characterise mine wastes in a report that describes the likely physical behaviour and chemical reactivity of the waste materials under the conditions in which they would be stored.” As such, further details are required to confirm that mine material characterisation have considered the conditions in which those materials will be stored (i.e., would there be ideal oxidizing conditions to cause selenium exceedance?). 16.4 The PRC plan contains limited details about soil amelioration and fertilisation. As per section 3.6.1 of PRCP Guideline, the rehabilitation planning part must include details of the site preparation required for rehabilitation activities including: a) The application and incorporation of ameliorants (if required for chemical balance) and bulk ameliorants such as gypsum, lime and other organic materials; and b) The application of fertilisers and where applicable, irrigation.
Asked forProvide an updated Rehabilitation Planning Part that includes details about topsoil stockpile height management noting the guidance by Mine Rehabilitation (industry.gov.au). The applicant is required to: (a) Provide further justification that the soil sampling regime is spatially and temporally representative; and (b) Pending (a), update the Rehabilitation Planning Part that will include soil characterisation based on spatially and temporally representative sampling data or commitment to conduct further soil sampling close to the landform construction to confirm design. Provide an updated Rehabilitation Planning Part that includes details about consistency of waste characterisation with section 3.6.1 of PRCP Guideline. Provide an updated Rehabilitation Planning part that includes details about ameliorants and fertilisers that will be used, application rates and method of incorporation. These details must also be provided in the PRCP schedule where appropriate.
Department foundSection 5.10 of PRC plan states that, “No engineered cover systems are required to manage the storage of mine materials at the WCP due to the low risk posed by the NAF/ NAF (barren) material ….” As per section 2.3 of Appendix B, only 2 coal rejects and tailings samples (one sample each) were analysed. There were 31 potential coal reject samples as well, however, were determined to have mineralogical composition similar to overburden. As such, and just like soil, the number of samples for rejects and tailings is not sufficient to determine whether an engineered cover design is required or not. As per Assessment and Management of Acid Drainage (DME, 1995) “sufficient samples should be taken to accurately characterise the nature, distribution and variability of critical parameters in each material type, including waste rock and ore samples. Ideally this should be based on accepted statistical procedures.” This guideline also provides details about minimum number of waste samples to be taken based on mass of each separate rock type (e.g., 3 samples for <10,000tonnes). The completeness of representative sampling is one of the biggest limitations in assessing mine waste characterisation results and the application must include enough information to address this concern. There is also lack of evidence (i.e., monitoring data) confirming the proposed systems will effectively reduce infiltration (and oxygen) to minimise seepage. This information is required prior to recommending the cover design are operating as designed and if these designs satisfy the completion criteria relevant to the final landform/PMLU.
Asked forProvide an updated Rehabilitation Planning Part that includes details about: (a) Completeness of tailings sampling; and (b) What design principles have been considered for the conceptual cover design that will minimise water infiltration and saline drainage. For details about cover design principals, please refer to section 3.6.1 of the PRCP guideline.
Applicant repliedWCP is a greenfield site. The commencement date for mining operations is yet to be confirmed. The current data from the tailings and reject sampling from ML 50230 is temporally representative for the current WCP mine plan as the first 35 years of mining only occurs in ML 50230. A 6.5 kg bulk sample of tailings filter cake was analysed which had been dewatered from a 25-35 % solids tailings slurry using a Plate and Frame Filter. The tailings slurry was processed in an off-site pilot plant from coal samples (n=17) from the Macalister Upper coal seam and is representative of typical tailings (i.e., clay and silt particles <0.06 mm) expected to be generated during the first 35 years of mining and coal processing at WCP. Additional rejects were sampled and analysed in KLC Test 9 and 10. When mining operations commence at WCP, further tailings sampling will be undertaken across site to cover the remaining MLs 50229 and 50231. Section 5.10 of PRCP does state that, “No engineered cover systems are required to manage the storage of mine materials at the WCP due to the low risk posed by the NAF/ NAF (barren) material”. Notwithstanding, the waste placement strategy at WCP includes the encapsulation of coarse coal rejects and dewatered tailings to minimise oxidising conditions. The encapsulation process involves the construction of bunded cells (nominally 50 m x 50 m x 1.5 high), in which both tailings and coarse rejects will be progressively placed, and encapsulated during the construction of the overburden emplacements which have a nominal lift height of 10 m between benches. Additionally, a minimum offset distance of 20 m from the face of the final landform has been adopted to minimise the risk of exposing cells during reshaping of the final landform. This strategy considers the principles outlined in Section 3.6.1 of the PRCP guidelines at a level appropriate for a greenfield site. For example: • The objectives of the encapsulation within the overburden emplacements are to minimise the exposure of dewatered tailings and rejects to oxidising conditions (e.g., water and air); and • A conceptual description of the design and construction methodology has been provided.
Department foundWater Erosion Prediction Project (WEPP) has been used for erosion assessment with results provided in Appendix J. The following issues have been identified with WEPP model: - No details about erodibility parameters, calibration and validation of the modelling; - Determines only rill erosion risk; - Does not determine high erosion risk areas and as such risk of erosion failure; - Does not determine the effects of significant hydrological events and biogenic factors; - Reports average and not maximum erosion rates; and - Does not consider steep weathered zone slopes. Based on above issues, the current rehabilitation planning part does not confirm the landform designs will achieve a stable condition.
Asked forUpdate the PRC plan to include a revised landform design and erosion assessment that can demonstrate a stable condition can be achieved as per section 111A of the EP Act. The revised erosion assessment must at a minimum include: (a) All input parameters including soil erodibility parameters; (b) Calibration, validation and sensitivity analysis based on locally obtained data; (c) Erosional hotspots from different erosion forms (including gullying and tunnel erosion); (d) An appropriate presentation of (c) such that the results can be interpreted by the reader and highlight areas of risk and modes of failure; (e) Effect of significant hydrological events and biogenic factors; (f) Maximum erosion rates; and (g) Consider entire landform including the unweathered steep slopes.
Applicant repliedThe level of detail in the erosion assessment is proportionate to the current stage of project development. As WCP remains at the planning and pre-disturbance phase, the purpose of the modelling is to inform conceptual landform design and demonstrate that a stable configuration is achievable in principle, rather than to provide final verification of performance. Detailed calibration, validation, and spatial hotspot mapping are typically undertaken during detailed design or operational stages when empirical monitoring data and site-specific samples are available. Appendix K has been updated to respond, in part, to IR Item 18. a) Input parameters were provided in the original submission including climate, soil and subsoil characteristics, landform slope design, surface roughness and vegetation input parameters. Additional information has been added to Section 5.5 of Appendix K regarding additional erodibility parameters both published and locally and regionally sourced from soil survey data. b) Section 5.6 of Appendix K has been added to describe the model calibration and validation processes and outlines sensitivity testing. c)-d) Additional information regarding the ability of WEPP to predict gully initiation risk has been provided in Section 7.3 of Appendix K. WEPP erosion rates >50–100 t/ha/yr, particularly on long unbroken slopes, are strongly correlated predictors of where gully formation processes are most likely to initiate. Erosion rates of this magnitude are not modelled to occur at WCP once vegetation is established. The adoption of a monitor and maintain approach to the identification and repair of gully formation at WCP is appropriate (Willgoose, G.R. & Loch, R.J. (1996), Moliere DR, Evans KG, Willgoose GR and Saynor MJ (2002) and Loch R, Dunlop J, and Nicolson L (2025)). The monitor and maintain framework provides a mechanism to validate modelling assumptions and adapt rehabilitation methods based on observed performance, consistent with the adaptive management principle under the EP Act. Whilst WEPP does not map high erosion risk areas across a final landform, it quantifies the erosion implications of alternative slope designs and vegetation covers, directly informing the landform design process. As such, the information presented in this section is sufficient for a greenfield operation that is still within the early planning and design phase and is considered appropriately presented for interpretation. In line with the leading practice guidance on erosion and landform evolution modelling to design post-mining landforms Technical Paper from the Office of the Qld Mine Rehabilitation Commissioner (OQMRC), simulations to guide landform design could be reasonably expected to use generic or estimated parameters with simulations aiming to achieve only a moderate level of accuracy when in the early planning stages of a new mine and especially when there are challenges that: • WCP may not proceed for various reasons; • Access to samples and data may be very limited; and • Planning of mining operations will be highly conceptual. Alternative models capable of simulating gully formation or spatial erosion hotspots (e.g. SIBERIA or CAESAR-Lisflood) require extensive calibration datasets that are not feasible for a greenfield site and offer limited benefit at this conceptual stage. e) Detailed consideration of extreme hydrological failure modes or biogenic disturbances are considered appropriate at later stages of the operational and closure phases, if required. There is no minimum requirement for an erosion assessment outlined in the PRCP Guidelines other than the landform design must include: • Erosion assessments to determine landform heights, gradients, profiles, and material placement; • Slope profile design considering the interactions between soil erodibility, rainfall erosivity, landform height, gradient and vegetation cover to identify acceptable erosion rates over a long-term average; and • Modelling predicting the long-term stability of the final landform design. The above minimum requirements have been provided in Appendix K. f) As appropriate for landform design decisions at a greenfield stage, results are presented as average annual erosion rates (t/ha/yr) across the modelling period to provide a long-term indicator of landform stability consistent with PRCP guideline requirements. g) Unweathered steep slopes cannot be considered in an erosion assessment as they are effectively non-erodible within the context of erosion models including WEPP. Their stability is addressed through the geotechnical assessment in Appendix M. Landform stability is a function of both geotechnical and surface erosion processes. The overall stability of the final landform is therefore not solely dependent on surface erosion modelling outputs but also on the engineered slope design, material placement, drainage control, and revegetation strategies. These aspects are addressed collectively across the PRCP supporting documents, including Appendix M and the rehabilitation strategy in Section 6 of the PRCP. This integrated approach demonstrates that the landform can achieve long- term stability consistent with section 111A of the EP Act.
Department foundThe applicant has elected to propose a PMLU of Native Bushland for both weathered (slopes 22%) and unweathered (slopes 214%) portions of highwalls. The narrow strips of Native Bushland proposed on the highwalls is unlikely to form a functioning ecosystem due to environmental conditions and isolation. Larger areas of native vegetation rehabilitation are strongly encouraged and in line with other outcomes approved under the current EA (refer appendix 2 below). It’s also not clear that what regional ecosystem(s) are targeted to be established. An appropriate PMLU for Woleebee Creek could involve the establishment of a Native Bushland, as the disturbance areas are currently designated for grazing in the PRCP. Regional Ecosystem (RE) 11.3.25 is identified as a suitable option. The watercourse retains remnant vegetation and serves as a key habitat for the threatened fauna recorded on the site. Maintaining and enhancing these ecological values would align with conservation priorities. Furthermore, the area between safety bund and the unweathered competent rock will have Native Bushland PMLU too. The purpose of safety bund is to provide exclusion zone as it provides space for highwall collapse. As such, it's unclear that how the native vegetation in this area will be monitored and managed. It’s also unclear that how native vegetation will establish successfully on steep slopes up to 214% on unweathered rocks.
Asked forFor high walls, provide a revised Rehabilitation Planning Part that includes: (a) Clarification on which regional ecosystem(s) are being aimed for with a view to developing completion criteria; (b) Discussion on why grazing is a more suitable PMLU compared to Native Bushland (woodland) in the areas with slopes >15% and especially >20%; (c) Sufficient details to demonstrate that steeper slopes up to 214% will achieve sustainable PMLU of Native Bushland; and (d) Details of how Native Bushland PMLU will be established, monitored and managed on the unweathered component of the highwall and area between safety bund and unweathered rocks.
Applicant repliedTable 5-1 and Table 6-1 of the PRCP have been updated to include the maximum slope for each highwall proposed in the final landform. Whilst the EA authorises highwall slopes up to 214%, approximate highwall slopes proposed in the landform are between 12 – 134 %. Specific regional ecosystems (REs) are not being targeted in the rehabilitation of native bushland PMLU’s. The seed mix to be used in native bushland PMLU rehabilitation includes species local to the area and likely to be successful in the rehabilitation of rocky slopes. Noting highwall slopes proposed in the landform are between 12 – 134 % with only three highwalls being ≥ 10 m in height (min height 2 m and max height 20 m). Both grazing and native bushland PMLUs are proposed for slopes over 15 % as per the PMLUs transitioned into the PRCP from the EA. As stated, areas of reprofiled overburden emplacements including lowwalls, with slopes up to 22 %, are assigned a grazing PMLU (This is further discussed in IR item 21) and the weathered and unweathered components of highwalls are assigned a PMLU of Native Bushland. Noting highwall slopes proposed in the landform are between 12 – 134 % with only three highwalls being ≥ 10 m in height (min height 2 m and max height 20 m). Section 5.7.2.3 and Appendix M of the PRCP describe the geotechnical stability of the highwalls and weathered zones. The three steepest and highest highwalls all have a FoS greater than 3. The risk of highwall collapse is minimal. Notwithstanding, a range of remote monitoring and management tools will be utilised such as monitoring with drones, aerial imagery and LiDAR. Section 8.1.1.7 and Table 8- 2 have been updated to include remote monitoring options.
Department foundSection 2.3.5 of PRC plan states that, “Nine REs were ground-truthed within the MLs during 2023 and 2024 field assessments undertaken by SLR (SLR, 2024c)...SLR undertook field surveys in spring 2023 and autumn 2023 and 2024 (in line with recommendations provided in Eyre et al. (2022a) for the Brigalow Belt bioregion).” However, ecological surveys/data have not been supplied to confirm statements and summaries made in section 2.3.5.
Asked forProvide ecological surveys / data to confirm statements and summaries made in section 2.3.5.
Applicant repliedSection 2.3.5 of the PRCP provided a summary of ecological survey data for context, and a summary of this ground-truthed information is also presented in Figure 2-10. Reference to the original report for further detail is sufficient, and the extent of detail provided in this baseline section is viewed as appropriate. Further details of the ecological surveys can be found in the SLR report (SLR, 2024c – Appendix C).
Department foundThe land class suitability proposed is also of a lower standard for some domains than approved under the current EA (refer table in appendix 2). Furthermore, it is not clear how grazing PMLU can be sustained on slopes up to 22% noting QMRC publication* which recommends a 15% maximum slope for grazing * Short TA. 2023. Rehabilitated mined land suitability for beef cattle grazing in the Bowen Basin: Technical paper 1. Brisbane: Queensland Mine Rehabilitation Commissioner, Queensland Government.
Asked forProvide revised Rehabilitation Planning Part that includes justification that PMLU of grazing is sustainable on the land with slopes >15% without severe limitations and management requirements and have land suitability class consistent with the EA.
Applicant repliedThis comment relates to Table 5-17 in the PRCP. Whilst the presentation of information in this table has been updated, the land suitability classes proposed in the PRCP and shown in Table 5-17 have never been of a lower class than those authorised under the EA. The EA describes the rehabilitation outcome of “land suitability” as defined in the DME 1995 Technical Guidelines for the Environmental Management of Exploration and Mining in Queensland. This outcome is to be transitioned into the PRCP. Grazing is proposed on slopes up to 22 % which is Class 4 and the justification has been provided in Section 3.2 and Table 3-1 of the PRCP and Table 3-1 of Appendix L. Class 4 land is considered marginal for grazing improved pastures but is generally considered suitable for grazing native pastures of varying quality all year round, depending on soil characteristics (QDME 1995, Shields and Williams 1991). In inland Central Queensland such country is typically termed ‘breeding country’. It encompasses a range in productivity from the lower end of Class 3 growing country through to the poorer end of Class 4 breeding country. Land suitability for sustainable grazing should be considered to be Class 4 breeding country for beef cattle, marginally suitable for grazing of improved pastures but suitable for grazing native pastures year-round, if seasons permit. It should also be noted that the QMRC publication refers to the Bowen Basin. The WCP is located within the Surat Basin.
Department foundWater in 8 reprofiled voids is proposed to be used by cattle opportunistically and when total dissolved salinity (TDS) is less than 4,000mg/L. As per Appendix I, salinity of water in those voids can be higher than cattle consumption suitable limits (>4000 mg/L) due to catchment run-off and low water volume. Appendix I also states that salinity will not accumulate over time “as salt is lost via infiltration and cattle water supply appears to offset salt mass inflow from runoff inflows.” The high salinity peaks have also been attributed to inherent nature of mass balance modelling approach and that it may not occur to such an extent in practice. Further details are required about: 1. Probability of scenarios when salinity levels will be high; 2. How cattle access will be limited in those times; and 3. Evidence that salinity peaks are due to nature of water balance model and that in practice it will not occur. This information is required to ensure that reprofiled void depressions will be able to sustain the targeted PMLU of stock watering.
Asked forFor stock watering PMLU of reprofiled void depressions, provide an updated Rehabilitation Planning Part that will include details about: (a) Probability of scenarios when water salinity levels will be high; (b) How cattle will be restricted during high salinity levels; and (c) Evidence that salinity peaks are due to nature of water balance model and that in practice it will not occur.
Applicant repliedItems a, b and c have been discussed in Sections 6 and 8 of Appendix J, and Section 5.5.2.4 and Table 5-6 in the PRCP have been updated. Summary of outcomes as follows: a) There is a 1 in 26 and 1 in 125 AEP of salinity levels exceeding the 4,000 mg/L and 5,000 mg/L beef cattle thresholds (respectively) in Austinvale reprofiled void depression. b) Alternative water sources, paddock rotations and a natural aversion to drinking salty water etc., are viable cattle management options when salinity levels are high. In addition, the behaviour of the waterbodies within the reprofiled void depressions reflects that of nearby existing ephemeral streams and pools, where isolated ponds with elevated salinity are expected to form during low volume periods. These wetting- drying cycles and associated salinity dynamics expected in the waterbodies of the reprofiled void depressions are consistent with natural conditions. For all reprofiled void depressions except Mud Creek, the reprofiled void depressions are expected to be used as supplementary supply when available for beef cattle water needs. The water supply from the reprofiled voids is during the wet season only (when there is a waterbody within the reprofiled void depression). Alternative water sources such as off-stream tanks and troughs would be used for cattle grazing with alternative water sources already being used in the dry season (as streams are ephemeral). c) Modelled salinity spikes occurred when water levels in the reprofiled void depression were low. These elevated concentrations are a result of the mass balance modelling approach, which assumes all salts remain dissolved, leading to conservative, potentially overstated, estimates during low- volume periods. In reality, salts are likely to precipitate and form crusts as water recedes, meaning actual salinity levels are expected to be lower than modelled.
Applicant repliedItems a, b and c have been discussed in Sections 6 and 8, with a summary of outcomes as follows: a) There is a 1 in 26 and 1 in 125 AEP of salinity levels exceeding the 4,000 mg/L and 5,000 mg/L beef cattle thresholds (respectively) in Austinvale reprofiled void depression. b) Alternative water sources, access restrictions, or cattle relocation are viable cattle management options. In addition, the behavior of the waterbodies within the reprofiled void depressions reflects that of nearby existing ephemeral streams and pools, where isolated ponds with elevated salinity are expected to form during low volume periods. These wetting-drying cycles and associated salinity dynamics expected in the of the reprofiled void depressions are consistent with natural conditions. For all reprofiled void depressions except Mud Creek, the reprofiled void depressions are expected to be used as supplementary supply when available for beef cattle water needs. The water supply from the reprofiled voids is during the wet season only (when there is a waterbody within the reprofiled void depression). Alternative water sources such as off-stream tanks and troughs would be used for cattle grazing with alternative water
Department foundAs per section 5.5 of PRC plan, 8 reprofiled void depressions will be ephemeral in nature. However, “For Mud Creek, the reprofiled void depression is expected to be able to sustain a waterbody for longer, with the cyclic filling and emptying expected to occur over larger periods of time (i.e., up to decades), because of the smaller, tiered base areas.” In addition to providing details required in IR item 23 above, further details are also required about implications of longer water retention on vegetation regrowth.
Asked forFor Mud Creek Void, provide details about impacts of longer water retention on vegetation regrowth. Noting the longer retention period, the modelled water quality results will also help determine its suitability for stock watering.
Applicant repliedThe potential impact of longer water retention on vegetation growth within the Mud Creek reprofiled void depression has been discussed in Section 6 of Appendix J. Plant species selection should align with the hydrological environment, which are expected to support enhanced root development, improved plant establishment, and increased species diversity. The suitability of Mud Creek reprofiled void depression for stock watering has been discussed in Section 7 of Appendix J. The extended water retention within this reprofiled void depression is expected to improve cattle supply, with Mud Creek being the only depression where the maximum modelled water availability is expected to meet the maximum cattle demand (for both stocking rates of 1 head/6 ha and 1 head/10 ha) consistently over the full 1,000 years modelled.
Department foundThe seed species proposed in Table 5-24 of the PRCP for areas with a grazing PMLU has been reviewed to confirm species are suitable to support a sustainable grazing outcome and are as per preferred and recommended pasture species for the grazing land types applicable to the location of the Wandoan Coal. The table contains some weed species and species like Buffel Grass that have ability to outcompete other species. The species list can also be improved by adding species like Black speargrass.
Asked forThe department recommends: a) Buffel is removed from the seed mix, given its ability to outcompete other species. It is acknowledged that buffel will likely regenerate from the seedbank within the topsoil and adjacent areas and be present in the final landform. b) Remove Stylosanthes hamata from the seed mix as it is an environmental weed and shouldn’t be sown due to the risk of it invading woodlands. c) The following additional species are added to the seed list to further enhance achievement of a sustainable grazing outcome: o Preferred: Black speargrass, cotton panic (Digitaria brownii), forest bluegrass, Queensland bluegrass, kangaroo grass, curly and bull Mitchell grass. o Intermediate: Curly windmill grass, summer grass, Brigalow grass, shot grass (Paspalidium globoideum).
Applicant replieda) Buffel has been removed from Table 5-24. However, it is noted that Buffel is already prevalent in the pre-mining landscape and is consistent with the PMLU and landholder species preference for grazing. b) Castinga Stylo (Stylosanthes hamata) has been removed from Table 5-24. c) Black Speargrass (Heteropogon contortus), Forest Bluegrass (Bothriochloa bladhii) and Queensland Bluegrass (Dichanthium sericeum) were already included in the grazing pasture / legumes section of Table 5-24. Cotton Panic (Digitaria brownii), Kangaroo Grass (Themeda triandra), Curly Mitchell Grass (Astrebla lappacea), Bull Mitchell Grass (Astrebla squarrosa), Curly Windmill Grass (Enteropogon acicularis), Summer Grass (Digitaria ciliaris), Brigalow Grass (Paspalidium caespitosum) and Shot Grass (Paspalidium globoideum) have been added to the grazing pasture / legumes section of Table 5-24. It is noted that the seed mix used on site will be dependent on availability of sourcing and other potential limiting factors, as noted in Section 5.12.3. To align with Table 5-24 updates, PRCP Schedule (Appendix O) Attachment 1 has been revised.
Department foundSection 5.4.2.3 of the PRC Plan states that “the exact location, size and operational detail of water infrastructure such as sediment dams will be confirmed and refined upon development of the WCP.” In the absence of information about location of those water infrastructures, it's difficult to determine whether those infrastructures will not be in floodplain. Appendix E provides that clean water storages will be supplied, however does not list particulars including quantity, location, volume etc.
Asked forProvide an updated Rehabilitation Planning Part containing further detail and clarity regarding water structure location to ensure that the final proposed locations are not in the floodplain.
Applicant repliedFigure 9-2 shows the location of WCP water infrastructure as RA5, the total area of RA5 Water Infrastructure is in Table 9-1. As per Section 5.4.2.3 the exact location, size and operational detail of water infrastructure such as sediment dams and storage dams will be confirmed and refined upon the development of the WCP. If required, the PRCP will be updated to capture any information regarding additional sediment and storage dams. Figure 5-10 of the PRCP and Figures 7.3-7.4 of Appendix I show the proposed water infrastructure does not interact with the 0.1% AEP whilst Appendix II of Appendix I shows no interaction for PMF. Section 5.4.2.3 of the PRCP has not been updated at this time.
Department foundSection 8.1.1.1 of PRC plan states that, “Rehabilitation success is often assessed using comparative reference sites. Reference sites will be established in REs and selected to attempt to reflect post-mining landform components which may include slope, aspect, water holding capacity and soil characteristic parameters.” Use of reference sites for monitoring and maintenance of rehabilitation success will require regular analysis of site data including multi-year comparison trends and benchmarking against analogue/reference sites. As such, the rehabilitation planning part must clearly identify the reference sites and evidence and justification of the rationale for selecting those sites.
Asked forThe applicant is required to: (a) Update the Rehabilitation Planning Part to either: i. Clearly identify the reference sites and evidence and justification for selecting those sites; or ii. Include the methodology that will be applied to select reference site prior to commencement of mining operations. (b) Provide spatial data files and/or maps showing location or proposed location of reference sites; and (c) Update milestone criteria as needed.
Applicant repliedPRCP Section 8.1.1.1 details the methodology that will be applied to select reference sites prior to the commencement of mining operations. As WCP is a greenfield site and the timing regarding the commencement of mining operations is unknown, no reference sites have been selected as yet. Spatial data and/or maps will be provided once sites are selected.
Department foundTo demonstrate a milestone and milestone criteria have been achieved the PRC plan should describe the monitoring and maintenance systems that will be carried out (refer to section 3.8 of PRCP Guideline). This should include description of methodologies and standards, which could include field-based assessments and the application of new remote sensing, GIS and other relevant emerging technologies. These methods and standards have not been provided in rehabilitation planning part.
Asked forProvide an updated rehabilitation planning part that will include details about monitoring methodologies and standards
Applicant repliedSection 8.1 of the PRCP provides an overview of monitoring methodology, including the use of an existing Rehabilitation Report Card (RRC) methodology which was originally developed by the University of Queensland (Erskine & Fletcher, 2014). The RRC has been subsequently expanded into a suite of manuals for different aspects of rehabilitation monitoring and has been extensively used by GCAA. As discussed in the IR Item 19 response, monitoring with drones, aerial imagery and/or LiDAR will also be used to monitor highwalls. Section 8.1.1.7 and Table 8-2 have been updated to include the above wording.
Department foundThere are some discrepancies in RA areas between the PRC plan and spatial files. For example, for RA2, there is difference of 10ha between PRC plan area (8,383ha) and spatial files (8, 373ha).
Asked forProvide updated spatial files to address discrepancy with PRC plan.
Applicant repliedUpdated spatial data with discrepancies addressed have been provided with this PRCP IR Response submission.
Department foundThe applicant has stated that there are 53 properties within the mining leases, 48 of which are owned by WCP JV. The remaining five (5) are privately owned properties. There are no details provided about privately owned properties.
Asked forProvide particulars (ownership details for these remaining privately owned properties).
Applicant repliedThe PRCP guidelines only requires the identification of the underlying landholders. WCP PRCP identifies the privately owned properties in Figure 2-19 of the PRCP. Ownership details relating to the five privately owned properties are not specifically required for the PRCP.
Department foundThe community consultation plan (CCP) provided in Appendix F lacks details about how feedback/comments will be considered during consultation.
Asked forProvide updated CCP that includes details about how feedback/comments will be considered
Applicant repliedAdded wording in Section 4.4.1 of the PRCP and Section 5 of Appendix G “Information and feedback from any consultation or engagement will be considered on a case-by-case basis. In some instances, options for change may be limited— particularly where regulatory requirements mandate specific actions. Any complaints will be documented and recorded in the Consultation Manager and escalated to the WCP Site Senior Executive. As of December 2025, WCP remains a greenfield project with commencement date for operations to still be confirmed, thus, no further community consultation has been undertaken. Community Consultation processes will recommence if the status of WCP changes."
Department foundAs per section 6.4 of PRC plan, “All water infrastructure will be either: (a) Retained under an agreement for stock watering purposes appropriate for a grazing PMLU; or (b) Decommissioned and rehabilitated, if required.” Section 9.2 of PRC plan allocates one RA (i.e., RA7) to all water infrastructure areas of 126ha. As per section 4.1 of PRCP Guideline, RAs must be based on the proposed rehabilitation methodology applicable to the PMLU and land that requires a specific type of rehabilitation strategy cannot be included into a broader area as there will be specific milestones only relating to a specific area of land within the larger area. This is the case herein whereby retained water infrastructure areas will have different rehabilitation methodology (i.e., ensuring water quality meets stock watering criteria and are safely accessible by cattle) than those to be decommissioned (i.e., landform reshaping, surface preparation, seeding etc). The same principal might be considered for RA1 whereby half of the pits will be designed to be free draining with remaining half reprofiled to become ephemeral water bodies.
Asked forTo be consistent with RA principles in the PRCP Guideline, it is recommended to separate RA7 into two RA’s with one for water infrastructure to be retained and other for water infrastructure to be decommissioned. Please consider the same principles and determine the need for separating RA1 into separate RAs with one for reprofiled shallow depressions and other for free draining.
Applicant repliedAt this stage, due to uncertainty regarding the retention of water infrastructure post-mining, the separation of RAs based on which structures will be retained would not be practical nor accurate. All dams are to be retained, only dams that cannot meet stock watering requirements will be decommissioned. As the site is still a greenfield site, the assessment of water quality cannot be undertaken to determine which dams cannot meet stock watering requirements. Therefore, RA5 (water infrastructure) has not been separated at this time. RA1 (pits including lowwalls and overburden emplacements) has not been subdivided based on whether the pits will be reprofiled shallow depressions or free draining. Splitting the RA is not required and RA1 remains as is.
Department foundTo determine appropriate timeframes for RA6, please provide predicted mine life duration. PRCP Schedule – this section identifies key criteria that are missing or not considered adequate in their current form. This is not an exhaustive list, and it is noted that further changes will be required following response to this information request notice.
Asked forClarify the predicted mine life duration.
Applicant repliedAs stated in Section 2.5 of the PRCP, WCP has an approximate LOM of 75 years.
Department foundThe PRCP schedule (Appendix N) includes milestone criteria and section 9.4 of the Rehabilitation Planning Part includes the milestones, criteria and justification. The PRCP schedule is lacking SMART criteria that reflects best practice.
Asked forProvide schedule with SMART criteria that reflects best practice: • Specific—it is clear what must be done • Measurable—it must be possible to know when it has been achieved • Achievable—it is capable of being achieved • Reasonable/relevant—there is a clear connection between the milestone and the desired outcomes. The requirement is reasonable • Time Specific—it is clear when the milestone will be completed.
Applicant repliedMilestone criteria have been updated to align with the IR response updates.
Department foundConsidering potential high risk to the Woleebee voids (Woleebee Creek, Woleebee North, and Woleebee North Satellite) and dumps under 0.1% AEP and PMF (Woleebee Creek void) development of relevant milestones and criteria are required to manage the issue. The PRCP Schedule should contain milestone criteria that are linked to the site-specific risks informed by the risk assessment such as flood protection landforms or rock armouring where there is a high risk of erosion due to high flood velocities.
Asked forProvide an updated PRCP schedule that contains milestone criteria that are linked to the site-specific risks associated with predicted flood levels and velocities under 0.1%AEP and PMF and are informed by the risk assessment.
Applicant repliedUpdated mapping for the 0.1% AEP velocities and discussion for the 0.1% AEP and PMF has been included around the Woleebee (Woleebee Creek, Woleebee North, and Woleebee North Satellite) dumps and voids. Refer to Section 7.3.2 of Appendix I and Section 5.3.2.2 of the PRCP. No voids are impacted by ingress of flood water in the 0.1% AEP event. For the toe of the dumps, scour will be mitigated through grassed vegetation of the final landforms. The PRCP Guideline states that voids in floodplains should be designed to withstand a 0.1% AEP event. The PMF is not used as a design criterion for the PRCP. PMF flood plain modelling is completed for information only and is not used to size erosion protection. Milestone criteria RM3.12 provides criteria to address site- specific risks associated with predicted flood levels (at the toe of the dumps) and velocities “For the interaction of landform and 0.1 % AEP, selective use of scour protection such as vegetation and/or rock mulch as determined by AQP”.
Applicant repliedUpdated mapping for the 0.1% AEP velocities and discussion for the 0.1% AEP and PMF has been included around the Woleebee (Woleebee Creek, Woleebee North, and Woleebee North Satellite) dumps and voids. Refer to section 7.3.2. No voids are impacted by ingress of flood water in the 0.1% AEP event. For the toe of the dumps, scour will be mitigated through grassed vegetation of the final landforms. The PRCP guidelines state that voids in floodplains should be designed to withstand a 1 in 1,000 AEP event. The PMF is not used as a design criterion for the PRCP. PMF flood plain modelling is completed for information only and is not used to sized erosion protection.
Department foundSection 9.5 of the Rehabilitation Planning Part states, “The WCP has not commenced mining operations and there are no defined completion dates, as such the date the areas become available for rehabilitation has been adapted as ‘XX’ in the PRCP Schedule for the relevant RA (Appendix N -)…Please note that the above has been used only as general guidance for completing the PRCP Schedule. The timing of when these milestones will be achieved must also be considered for rehabilitation to be completed effectively and efficiently. For example, seeding should take place at the end of the year before the wet season and ideally is done soon after the application of topsoil. Milestones should also be aligned to maximise efficiency, where possible.”
Asked forIt is noted that the applicant has proposed yearly timeframes in some of the RA tables (e.g. RA1). Provide an updated PRCP Schedule based on: (a) Timeframes proposed in Table 9-3. (b) When milestones are completed by, as opposed to listing all years (year 3-9), especially where the cumulative area available remains the same for subsequent years.
Applicant replieda) Table 9-3 of the PRCP demonstrates the timeframe of each rehabilitation milestone. The PRCP Schedule timing is based on these timeframes. For example, RM8 timeframe is 10 years, in RA1 RM6 is completed by 10/12/20XX+8 (which is when RM8 timeframe begins) and RM8 is completed by 10/12/20XX+18. b) The PRCP Schedule timing has been updated to show the areas and milestones in 5-year increments, where applicable. The increment is larger in some RAs due to no area becoming available for an extended period of time. Where the area available is the total, the timeframes remain the same based on the milestone timeframes and when they are completed by.
Department foundRM1 does not include any criteria about removal of machinery. Additionally, for retained infrastructure, there is no criteria to state that those infrastructure will be safe, stable and non-polluting.
Asked forProvide an updated PRCP schedule that contains: (a) Criteria for removal of machinery and equipment; and (b) SMART criteria for infrastructure to demonstrate stable condition*. *stable condition: as per section 111A of the EP Act, land is in a stable condition if— (a) the land is safe and structurally stable; and (b) there is no environmental harm being caused by anything on or in the land; and (c) the land can sustain a post-mining land use
Applicant replieda) Milestone criteria added into Table 9-2 of the PRCP for the removal of machinery and equipment. “All machinery and equipment, not required for rehabilitation works removed from site”. b) The SMART criteria for stable condition are in RM9 achievement of PMLU to stable condition.
Department foundContaminated land criteria should also include consideration of hazardous material.
Asked forProvide an updated PRCP Schedule that includes consideration of hazardous material.
Applicant repliedHazardous material wording has been added into RM2. Table 9-2 of the PRCP has been updated.
Department foundFor landform reshaping, RM3 lacks details about geotechnical safety criteria. This geotechnical safety criterion is required to ensure that final landform will be safe and stable.
Asked forProvide an updated PRCP Schedule that includes geotechnical safety criteria to be achieved when reshaping land for example, ‘Constructed landform achieves geotechnical stability with a Factor of Safety (FOS) ≥ 1.5, which includes consideration of flood stress.’
Applicant repliedRM3.5 and 3.11 have been included to address the landform stability and consideration of flood stress. These RMs are consistent with criteria of other GCAA mine sites. Table 9-2 of the PRCP and Appendix O has been updated.
Department foundBased on the WEPP modelling outputs in the Rehabilitation Planning Part, stable landform is achieved when slope length is 100m. In addition, section 5.10 of the Rehabilitation Planning Part states that, “Spontaneous combustion risks are managed through the design of the encapsulation cells and ensuring the height of the reject and tailings paddock dumped within the cells stay within the critical thickness limits (≤ 2m).” Appendix L also recommended that for closure considerations a minimum offset of 20m of any tailings cell from the final landform. Information about slope length as determined by WEPP modelling, reject and tailings paddock height within overburden and offset distance between tailings cell and final landform has not been used to inform PRCP schedule criteria. As per section 12 of Common Issues with Progressive Rehabilitation and Closure Plan Applications (PRCP applications), the milestone criteria as justified in the Rehabilitation Planning Part must be linked in PRCP schedule.
Asked forProvide an updated PRCP Schedule that includes milestone criteria regarding landform design such as slope length, setback distance between tailings cells and final landform face that are explained and justified in the Rehabilitation Planning Part.
Applicant repliedRM3 criteria has been revised and updated to the slope length, rejects and tailings cell setback from final landform (RM3.8 and 3.9). Table 9-2 of the PRCP and Appendix O has been updated.
Department foundThis RM about removal of carbonaceous material could be merged with RM2.
Asked forIt is recommended to provide an updated PRCP Schedule that is clear and concise, such as merging of carbonaceous material removal RM4 with RM2.
Applicant repliedAn update is not required. RM4 is applied differently across RA3 and RA4, leaving RM4 separated keeps RM2 clear and concise.
Department foundThe Rehabilitation Planning Part (section 5.6.1.2) provides details about erosion mitigation measures for bare soil during initial 1.5 years post- rehabilitation. One of the measures is, “Using high seeding rates for grasses and high fertiliser rates to facilitate establishment.” This information has not been linked in the PRCP schedule. As stated above, the milestone criteria as justified in the Rehabilitation Planning Part must be linked in PRCP schedule.
Asked forProvide an updated PRCP Schedule that includes milestone criteria explained and justified in the Rehabilitation Planning Part in relation to erosion mitigation measures.
Applicant repliedSeeding (RM6) activities will occur at the same time as surface preparation (RM5). Native and pasture grazing grass species seeding rate is 15 kg/ha for both native bushland and grazing PMLUs. This methodology is sufficient as an erosion mitigation measure. No milestone criteria are required.
Department foundRevegetation criteria are not SMART and lack details about: (a) Exclusion of stock from newly seeded areas (i.e., fencing criteria) (b) Fertilization of topsoil (Section 5.6.3.2 of the PRC Plan) states that, “A controlled release fertiliser is to be applied at the time of ripping and seeding activities”).
Asked forProvide an updated PRCP Schedule that includes milestone criteria to ensure that the final landform will be safe, stable, non-polluting, and that completion of each milestone will help progress to the upcoming milestone.
Applicant replieda) Fencing criteria has been added to RM6.3 in Table 9-2 of the PRCP “Livestock are excluded from newly seeded areas via physical or virtual fencing”. b) Fertiliser has been added to RM5.3 criteria wording in Table 9-2 of the PRCP.
Department foundBetween revegetation (RM6) and achievement of PMLU (RM8 and RM9), there must be milestone criteria to demonstrate achievement of surface requirements including but not limited to: • Erosion stability; and • Non-polluting surface water quality.
Asked forProvide an updated PRCP Schedule that includes appropriate and relevant milestone criteria to demonstrate the trajectory to achieving progressive rehabilitation.
Applicant repliedTable 9-2 and Appendix O has been updated with the revised RMs for 8, 9 and 10 to include relevant milestone criteria to demonstrate the trajectory to achieving progressive rehabilitation and are consistent with the RMs of other Glencore mine sites. The following are the new RMs: • RM8: achievement of surface requirements; • RM9: achievement of post-mining land use to a stable condition; and • RM10: achievement of post-mining land use water quality.
Department foundThere is only a one year gap between seeding (RM6) and achievement of PMLU (RM8 and RM9). This timeframe to achieve ≥65% ground cover for grazing is not practical and is also inconsistent with Rehabilitation Planning Part that states soil will be bare for initial 1.5 years while vegetation cover establishes (i.e., after seeding).
Asked forProvide an updated PRCP Schedule that considers appropriate time required to achieve each rehabilitation milestone and as discussed in the Rehabilitation Planning Part.
Applicant repliedRM8 and RM9 have a 10 year and 15-year gap between RM6, allowing for vegetation establishment for PMLU grazing and native bushland. Appendix O PRCP Schedule has been updated to show 5-yearly intervals. Section 9.5 of the PRCP has been reworded and Table 9-3 has been removed to avoid confusion around the milestone timeframes for the PRCP Schedule.
Department foundMaximum erosion rates for grazing and Native Bushland PMLU are 17.4 and 19 t/ha/yr, respectively. An erosionally stable postmining landform will have a rate of erosion not greater than the rate of soil formation, which is thought to be less than 4 t/ha/y (Grigg et al., 2001)*. Bowen Basin has typical erosion rates of <5t/ha/yr with some landforms (over 350m elevation) tending towards higher erosion rates of 5-10t/ha/y. As such, for erosional stability an erosion rate of 5 – 10 t/ha/y is considered acceptable. * Grigg, AH, Emmerton, BR and Callum, NJ (2001) The development of draft completion criteria for ungrazed rehabilitation pastures after open-cut coal mining in central Queensland. ACARP project C8038. Australian Coal Association Research Program (ACARP).
Asked forProvide an updated PRCP Schedule that includes SMART erosional stability criteria to demonstrate the achievement of stable condition.
Applicant repliedMaximum and average erosion rate criteria have been removed and replaced with the Erosion Classification Framework - Attachment 2 of the PRCP Schedule (Appendix O). These are now RM8.5 and 8.6. Table 9-2 of the PRCP and Appendix O has been updated.
Department foundRM10(i) states no gullies ≤3m and then RM10(j)(i) allows gullies up to 1m depth. The Australian Government (2016) states that during the landform design process, to manage risk on Australian mine rehabilitation sites, it is important to adopt a target erosion rate where rill and gully development is unlikely, and which considers the receiving environment and PMLU. Please note that as per recent publication by QMRC, “Gullies on dispersive or hazardous material (e.g. Potentially Acid Forming material (PAF)) are not considered an acceptable risk, and the landform design process should seek to inhibit the initiation and development of rill and gully features.” The publication also states that, “The issue of gully presence and density is an important consideration. As mine waste landforms are constructed from unconsolidated material, incisions such as rills and gullies are not constrained such as they are in natural landforms, by underlying bedrock (Australian Government 2016). These conditions provide the opportunity for incisions to continue developing until all the mine waste material has been discharged to the surrounding environment the landform design process should seek to inhibit the initiation and development of rill and gully features.” For gullies and erosional stability, the attached erosion classification framework (Appendix 3) is considered the standard and acceptable approach. * Applying erosion and Landscape Evolution Models to assess post- mining landform stability: Technical Paper
Asked forProvide an updated PRCP Schedule that includes SMART erosional stability criteria to demonstrate the achievement of stable condition.
Applicant repliedRM10(i) has been revised to RM9.7 and 9.8. The criteria have been updated to include SMART erosional stability framework with Attachment 2 of the PRCP Schedule (Appendix O) Erosion Classification Framework, DETSI has proposed at other GCAA sites. Table 9-2 of the PRCP and Appendix O has been updated.
Replies to requests not published on the register: 4
Request, as quoted by the applicantSoil and overburden quality and management Section 5.6.2 of PRC plan provides details about topsoil stockpile planning and placement. There is no mention of stockpile height that has direct relationship with soil health* and must be considered when planning for stockpiling. As per Mine Rehabilitation (industry.gov.au) standard topsoil stockpiles height is <2m and a greater height can result in significant deterioration of soil physicochemical and biological properties. This information is required to ensure that sufficient quality topsoil will be available for rehabilitation activities. Provide an updated Rehabilitation Planning Part that includes details about topsoil stockpile height management noting the guidance by Mine Rehabilitation (industry.gov.au). * Fischer, A. M., Van Hamme, J. D., Gardner, W. C., & Fraser, L. H. (2022). Impacts from topsoil stockpile height on soil geochemical properties in two mining operations in British Columbia: implications for restoration practices. Mining, 2(2), 315-329.
Applicant repliedSection 5.6.2 of the PRCP has been updated to include text for a maximum stockpile height of 3 metres (where practical) as per GCAA Rehabilitation Guidelines. Direct return / placement of topsoil is preferred and should be utilised where mine scheduling and haul distances apply to minimise the disturbance footprint. Additionally, maximising topsoil stockpile heights whilst maintaining topsoil health also reduces the disturbance footprint required to store topsoil. The below studies review stockpile heights and consider 3 m to be the maximum height for topsoil stockpiles to still maintain reasonable topsoil health at 3 m and have been included in the list of references in the PRCP Fischer A, Singh JP, Van Hamme J, Bottos E and Fraser LH (2025) Investigating impacts from topsoil stockpile height on soil microbial communities. Front. Microbiomes 4:1607677. doi: 10.3389/frmbi.2025.1607677 Mackenzie DD, Naeth MA (2019) Native seed, soil and atmosphere respond to boreal forest topsoil (LFH) storage. PLOS ONE 14(9): e0220367. https://doi.org/10.1371/journal.pone.0220367
Request, as quoted by the applicantSoil and overburden quality and management Section 2.3.4.4 of PRC plan provides soil quality results. Soil pH and Exchangeable Sodium Percentage (ESP) results are from 2008. The sampling regime for waste characterisation must meet the best practise standards. One of such standards is to have temporally representative i.e., most recent data. Having knowledge of mine material properties as close to the landform construction as possible will ensure that each material is suitable both for its final placement in the landform, and for the target plant community to be re-established. For soil quality characteristics, other than pH and ESP, Appendix B provides latest results from 2024. However, a total of 11 soil samples from a maximum of 9 sampling sites (one bulk pit and 8 drill holes), all located within one mining lease (ML50230), were chosen. To meet the best practice standards, sampling regime must also be spatially representative with sample numbers sufficient to characterise all soils that would be disturbed and/or used in rehabilitation of the site. The rate of sampling should be like those used in precision agriculture which is around 1 test site per 5ha as long as the material is of a similar nature. The applicant is required to: (a) Provide further justification that the soil sampling regime is spatially and temporally representative; and (b) Pending (a), update the Rehabilitation Planning Part that will include soil characterisation based on spatially and temporally repr
Applicant repliedWCP is a greenfield site. The commencement date for mining operations is yet to be confirmed. As such, the final landform design is conceptual. The current data from soil sampling from ML 50230 is spatially and temporally representative for the current WCP mine plan. The soil quality presented in Section 2.3.4.4 of the PRCP represents the first 35 years of mining at WCP. When mining operations commence at WCP, further soil sampling will be undertaken across site to cover the remaining MLs 50229 and 50231. Updates to Section 2.3.4.4 of the PRCP have not been made at this time.
Request, as quoted by the applicantSoil and overburden quality and management Section 4 of Appendix B states that, “selenium can have a concentration greater than the livestock drinking water value (ANZG, 2018) under ideal oxidising conditions.” It also states that, “Overall, dissolved metal/metalloid concentrations in surface runoff and seepage from the mine materials are unlikely to present a significant risk to surface and groundwater resources with the expectation that the material will be handled according to standard industry mine waste management practices.” To confirm the final landform will be stable and non-polluting, section 3.6.1 of PRCP Guideline requires the plan to “Characterise mine wastes in a report that describes the likely physical behaviour and chemical reactivity of the waste materials under the conditions in which they would be stored.” As such, further details are required to confirm that mine material characterisation have considered the conditions in which those materials will be stored (i.e., would there be ideal oxidizing conditions to cause selenium exceedance?). Provide an updated Rehabilitation Planning Part that includes details about consistency of waste characterisation with section 3.6.1 of PRCP Guideline.
Applicant repliedAppendix B describes several instances where the Kinetic Leach Column (KLC) results for Selenium concentrations exceed the livestock drinking water value (ANZG, 2018) of 0.02 mg/L. The highest selenium concentration recorded is 0.07 mg/L and is associated with the results from coal reject samples. KLC testing represents the “worst case scenario” or the ideal oxidising conditions. It represents the dynamic quality of contact water if the mine materials are left unmanaged and exposed to oxidising conditions. Additionally, KLC samples were crushed to pass a 10 mm sieve size, where required, maximising the surface area available for geochemical reaction and further creating the ideal oxidising conditions. As discussed in Section 5.8.4 Waste Placement Strategy and 5.9 Tailings Management, the tailings / reject material will be bunded and progressively encapsulated within overburden material, with a separation offset of 20 m between the encapsulation cell and the nearest exposed final batter as illustrated in Figure 5-4. This strategy aims to minimise oxidising conditions through encapsulation and under these conditions, it is considered unlikely that the ideal oxidizing conditions (i.e., those similar to a KLC test) would occur resulting in a selenium exceedance. Figures 5-25 to 5-27 of the PRCP details the progressive encapsulation and management of tailings / rejects. This approach to waste characterisation is considered appropriate for the WCP. No further information has been added to the PRCP Planning Part.
Request, as quoted by the applicantSoil and overburden quality and management The PRC plan contains limited details about soil amelioration and fertilisation. As per section 3.6.1 of PRCP Guideline, the rehabilitation planning part must include details of the site preparation required for rehabilitation activities including: a) The application and incorporation of ameliorants (if required for chemical balance) and bulk ameliorants such as gypsum, lime and other organic materials; and b) The application of fertilisers and where applicable, irrigation. Provide an updated Rehabilitation Planning part that includes details about ameliorants and fertilisers that will be used, application rates and method of incorporation. These details must also be provided in the PRCP schedule where appropriate.
Applicant repliedSection 5.6.3.2 and Section 5.12.2 provide methodology for the use of fertilisers and ameliorants during rehabilitation. As WCP is a greenfield site, the type, application rate and method of incorporation of fertilisers and ameliorants will be determined following topsoil analysis of the topsoil stockpiles or direct stripped areas and will be determined by an appropriately qualified person. As per Item 16.2 response further soil sampling will be required when WCP mining operations commence. Soil parameters in milestone criteria RM5.2 should be updated to align with the results of the sampling data. Milestone criteria RM5.3 has been updated to include fertiliser.