2022-01-19_REVISION - M1976007UG ‎(135)‎

• Permit No: M1976007UG
• IBM Index Class Name: Revision
• Doc Date: 1/19/2022
• Doc Name: Comment/Objection
• From: Ian Wilson
• To: DRMS
• Type & Sequence: CN1
• Email Name: ECS
• Email Name: MAC
• Media Type: D

Page iv
Mt Arthur Coal Open Cut Modification (Project No. G1602)

TABLE OF CONTENTS
(Continued)
Page No.

List of Tables:

Table 1: Average Monthly Precipitation Jerrys Plains Post Office (061086) (1884 to 2012)................................................................ 18
Table 2: Details of Seams being Mined by HVEC ................................................................................................................................ 23
Table 3 : Groundwater Quality-Alluvium............................................................................................................................................... 31
Table 4: Pre-Mining Groundwater Quality-Permian Groundwater Systems ......................................................................................... 35
Table 5: Monitoring Bores along the Hunter River ............................................................................................................................... 36
Table 6: Summary of Groundwater Model Parameters ........................................................................................................................ 56
Table 7: Steady State Model Calibration Results ................................................................................................................................ 57
Table 8: Model Steady State Water Budget ........................................................................................................................................ 61
Table 9: Simulated Groundwater Discharge to the Creeks and Hunter River ..................................................................................... 61
Table 10: Predicted Average Inflow to the Pits (ML/day) .................................................................................................................... 67
Table 11: Predicted Flux to and from Alluvium (ML/day) .................................................................................................................... 72
Table 12: Pit Lake Recovery Model Scenarios .................................................................................................................................... 79
Table 13: Groundwater Licence Summary .......................................................................................................................................... 82
Table 14: Licensing Requirement Summary ....................................................................................................................................... 82

List of Figures:

Figure 1: General Location Plan ............................................................................................................................................................ 2
Figure 2: Mt Arthur Mine Modification Study Area.................................................................................................................................. 3
Figure 3: Locality Map for the Hunter Regulated River Water Sharing Plan ......................................................................................... 9
Figure 4: Water Sharing Plan Area for the Hunter Unregulated and Alluvial Water Sources.............................................................. 10
Figure 5: Buffer Zone Requirement for Open Cut Mining Operations Next to Rivers/Alluvium ........................................................... 12
Figure 6: Three-Dimensional View of Mt Arthur Coal Mine .................................................................................................................. 18
Figure 7: Existing Mine Leases and Conceptual Model Area .............................................................................................................. 19
Figure 8: Jerrys Plains Post Office (061086) Monthly Rainfall Data and CRD..................................................................................... 20
Figure 9: Stratigraphic Column ............................................................................................................................................................ 22
Figure 10: Geology Map and Major Structures .................................................................................................................................... 24
Figure 11: Overview of Main Faults and Structures within Mt Arthur Coal Mine and Surrounds ......................................................... 25
Figure 12: Monitoring Bore and NOW Registered Bore Location ........................................................................................................ 28
Figure 13: Interpreted Groundwater Table ........................................................................................................................................... 34
Figure 14: Hydrographs of Selected Monitoring Bores along the Hunter River ................................................................................... 37
Figure 15: Electrical Conductivity Trends of Monitoring Bores............................................................................................................. 38
Figure 16: Hydrographs of Permian Coal Measures Monitoring Bores-Saddlers Creek ...................................................................... 39
Figure 17: Hydrographs of Permian Coal Measures Monitoring Bores – North-West.......................................................................... 40
Figure 18: Hydrographs of Permian Coal Measures Monitoring Bores – South-East .......................................................................... 40
Figure 19: Updated Mine Plan 2016 to 2026 ....................................................................................................................................... 43
Figure 20: Model Area and Finite Element Mesh (FEM) and Boundary Conditions............................................................................. 46
Figure 21: Structure Contours of base of Layer 4 (top Mt Arthur Seam) and Hydraulic Conductivity Distribution ............................... 48
Figure 22: Structure Contours of base of Layer 6 (Bayswater Seam) and Hydraulic Conductivity Distribution ................................... 49
Figure 23: Structure Contours of base of Layer 7 (Base Ramrod Seam) and Hydraulic Conductivity Distribution .............................. 50
Figure 24: Three-Dimensional Model Mesh ......................................................................................................................................... 51
Figure 25: Assumed Low Conductivity Zone with Nearby Monitoring Bores........................................................................................ 52
Figure 26: Long Sections - Hydraulic Conductivity .............................................................................................................................. 54
Figure 27: Recharge Distribution ......................................................................................................................................................... 55
Figure 28: Calibrated Steady State Observed vs. Modelled Heads Scatter Plot ................................................................................. 58
Figure 29: Calibrated Steady State Water Table Contours .................................................................................................................. 59
Figure 30: Transient Verification Hydrographs Associated with Alluvium ............................................................................................ 62