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

TABLE OF CONTENTS
(Continued)
Page No.

9.3.1 Distribution ..................................................................................................................... 29
9.3.2 Hydraulic Parameters ..................................................................................................... 29
9.3.3 Yield ............................................................................................................................... 30
9.3.4 Groundwater Levels and Hydraulic Gradients ................................................................. 30
9.3.5 Regional and Local Recharge, Discharge and Groundwater Flow .................................. 30
9.3.6 Water Quality .................................................................................................................. 30
9.3.7 Groundwater Dependent Ecosystems ............................................................................ 31
9.4 Shallow Bedrock (Regolith) ................................................................................................ 32
9.5 Permian ............................................................................................................................. 32
9.5.1 Distribution ..................................................................................................................... 32
9.5.2 Hydraulic Parameters ..................................................................................................... 33
9.5.3 Yields ............................................................................................................................. 33
9.5.4 Groundwater Levels and Hydraulic Gradients ................................................................. 33
9.5.5 Regional and Local Recharge, Discharge and Groundwater Flow .................................. 35
9.5.6 Water Quality .................................................................................................................. 35
10.0 IMPACT OF MINING TO DATE ............................................................................. 36
10.1 Impact of Mining on Hunter River Alluvium ......................................................................... 36
10.1.1 Hydrographs ................................................................................................................... 36
10.1.2 Electrical Conductivity .................................................................................................... 38
10.2 Impact of Mining on Saddlers Creek Alluvium .................................................................... 38
10.3 Impact of Mining on Permian Coal Measures ..................................................................... 39
10.4 Summary and Conclusions ................................................................................................ 41
11.0 MINE PLAN ........................................................................................................... 42
12.0 NUMERICAL GROUNDWATER MODEL .............................................................. 44
12.1 Modelling Objectives .......................................................................................................... 44
12.2 Conceptual Model .............................................................................................................. 44
12.3 Model Development ........................................................................................................... 44
12.3.1 Model Settings ................................................................................................................ 45
12.3.2 Model Geometry and Model Extents ............................................................................... 45
12.3.3 Boundary Conditions ...................................................................................................... 45
12.3.4 Layers ............................................................................................................................ 45
12.3.5 Hydraulic Parameters ..................................................................................................... 47
12.3.6 Recharge and Discharge ................................................................................................ 53
12.4 Model Calibration ............................................................................................................... 57
12.5 Calibrated Model Validation ............................................................................................... 60
12.6 Pre-Mining Groundwater Balance ...................................................................................... 61
12.7 Predictive Model Verification .............................................................................................. 61
12.7.1 Verification Summary ..................................................................................................... 63