groundwater and geology technical report - Arrow Energy

299 Pages·2013·40.76 MB·English

L
GROUNDWATER
AND GEOLOGY
TECHNICAL REPORT
ENTER HERE
BACK TO CONTENTS
Report
Groundwater Impact Assessment
Bowen Gas Project

NOVEMBER 2012
Prepared for
Arrow Energy Pty Ltd
GPO Box 5262
Brisbane Qld 400

42626960
Groundwater Impact Assessment - Bowen Gas Project

URS Australia Pty Ltd
Level 17, 240 Queen Street
Brisbane, QLD 4000
GPO Box 302, QLD 4001Australia
Principal-In-Charge:
T: 61 7 3243 2111
F: 61 7 3243 2199

Daymion Jenkins
Principal Environmental
Geologist
Author:

Delton Chen
Principal Groundwater
Modeller
Reviewer: Date: November 2012
Reference: 42626960/1/E
Status: Final

Mark Stewart
Principal Hydrogeologist

Document copyright of URS Australia Pty Limited
This report is submitted on the basis that it remains commercial-in-confidence. The contents of this
report are and remain the intellectual property of URS and are not to be provided or disclosed to third
parties without the prior written consent of URS. No use of the contents, concepts, designs, drawings,
specifications, plans etc. included in this report is permitted unless and until they are the subject of a
written contract between URS Australia and the addressee of this report. URS Australia accepts no
liability of any kind for any unauthorised use of the contents of this report and URS reserves the right
to seek compensation for any such unauthorised use.

Document delivery
URS Australia provides this document in either printed format, electronic format or both. URS
considers the printed version to be binding. The electronic format is provided for the client’s
convenience and URS requests that the client ensures the integrity of this electronic information is
maintained. Storage of this electronic information should at a minimum comply with the requirements
of the Commonwealth Electronic Transactions Act (ETA) 2000.
Where an electronic only version is provided to the client, a signed hard copy of this document is held
on file by URS and a copy will be provided if requested.
Groundwater Impact Assessment - Bowen Gas Project
Table of Contents
Executive Summary ............................................................................................... xiv 
1 Introduction ............................................................................................................. 1 
1.1  Purpose and Objectives of the Groundwater Assessment ............................ 3 
1.2  EIS Terms of Reference ..................................................................................... 3 
1.3  Scope of Work .................................................................................................... 7 
1.4  Legislative Framework ...................................................................................... 7 
1.5  Description of Study Area ............................................................................... 11 
1.5.1  Project Area .................................................................................................................... 11 
1.5.2  Study Area ...................................................................................................................... 11 
1.5.3  Land Use ......................................................................................................................... 11 
1.5.4  Climate ............................................................................................................................ 12 
1.5.5  Rainfall Variability .......................................................................................................... 13 
1.5.6  Surface Drainage ...........................................................................................................1 4 
1.5.7  Stream Flow .................................................................................................................... 15 
2 Study Approach and Previous Studies ............................................................... 18 
2.1  Basis of Study Approach of EIS ..................................................................... 18 
2.1.1  Study Area and Numerical Model .................................................................................1 8 
2.1.2  Methodology ................................................................................................................... 18 
2.1.3  Data Extracts and GIS Maps .........................................................................................2 0 
2.2  Available Hydrogeological Studies ................................................................ 21 
3 Geology ................................................................................................................. 23 
3.1  Structural Geology and Setting ...................................................................... 23 
3.2  Geological Evolution ....................................................................................... 26 
3.3  Structural Controls .......................................................................................... 27 
3.4  Mapped Geology .............................................................................................. 27 
3.5  Stratigraphy ...................................................................................................... 28 
3.5.1  Quaternary ...................................................................................................................... 30 
3.5.2  Tertiary ............................................................................................................................ 30 
3.5.3  Triassic ............................................................................................................................3 1 
3.5.4  Permian ........................................................................................................................... 31 
3.5.5  Back Creek Group ..........................................................................................................3 2 
42626960/1/E i
Groundwater Impact Assessment - Bowen Gas Project
Table of Contents
3.6  Coal Seam Geology within the Gas Production Fields ................................ 32 
4 Hydrogeology ....................................................................................................... 39 
4.1  Monitoring Bores ............................................................................................. 39 
4.2  Hydrostratigraphy ............................................................................................ 41 
4.3  Aquifers ............................................................................................................ 43 
4.3.1  Quaternary Alluvial Aquifers ........................................................................................4 3 
4.3.2  Tertiary Sediment Aquifers ...........................................................................................4 4 
4.3.3  Tertiary Basalt Aquifers ................................................................................................4 6 
4.3.4  Moolayember Formation Aquitards .............................................................................4 7 
4.3.5  Clematis Sandstone Aquifers .......................................................................................4 8 
4.3.6  Rewan Formation Aquitards .........................................................................................4 8 
4.3.7  Permian Strata Aquifers and Aquitards .......................................................................4 9 
4.4  Hydraulic Parameters ...................................................................................... 52 
4.5  Groundwater Levels ........................................................................................ 54 
4.5.1  Quaternary Alluvial and Tertiary Sediment and Basalt Aquifers ..............................5 4 
4.5.2  Clematis Sandstone Aquifers .......................................................................................5 7 
4.5.3  Permian Strata Aquifers ................................................................................................6 2 
4.6  Groundwater Flow ........................................................................................... 66 
4.6.1  Recharge Influence on Flow .........................................................................................6 6 
4.6.2  Unconfined Quaternary and Tertiary Aquifers............................................................6 6 
4.6.1  Permian Strata Aquifers ................................................................................................6 6 
4.6.2  Unconfined Clematis Sandstone Aquifers ..................................................................6 7 
4.6.3  Surface Water-Groundwater Interaction ......................................................................6 7 
4.6.4  Springs ............................................................................................................................ 68 
4.6.5  Inter-Aquifer Flow ..........................................................................................................6 9 
4.6.6  Faults and Folds ............................................................................................................6 9 
4.7  Groundwater Quality ....................................................................................... 70 
4.7.1  Methodology ................................................................................................................... 70 
4.7.2  Tolerances for Consumptive Use .................................................................................7 0 
4.7.3  Groundwater Quality Map .............................................................................................7 2 
4.7.4  Groundwater in Aquifer Units .......................................................................................7 5 
4.7.5  Groundwater in River Alluvium and Sediments ......................................................... 76 
4.7.6  Groundwater in Tertiary Basalt ....................................................................................8 1 
42626960/1/E ii
Groundwater Impact Assessment - Bowen Gas Project
Table of Contents
4.7.7  Groundwater in the Mimosa Group ..............................................................................8 1 
4.7.8  Blackwater Group ..........................................................................................................8 1 
4.7.9  Groundwater in the Back Creek Group .......................................................................8 5 
4.7.10  Hydrochemistry Variation across the Project Area ....................................................8 6 
4.8  Groundwater Resource Development ............................................................ 87 
4.8.1  Groundwater Management Areas ................................................................................8 7 
4.8.2  Groundwater Allocations and Usage ...........................................................................8 7 
4.8.3  Groundwater Bores .......................................................................................................9 7 
4.8.4  Bore Yields ..................................................................................................................... 97 
4.8.5  Sustainability .................................................................................................................. 98 
4.9  Groundwater Dependent Ecosystems ........................................................... 99 
4.10  Conceptual Hydrogeological Model ............................................................. 101 
4.10.1  Groundwater Recharge ...............................................................................................101 
4.10.2  Evapotranspiration and Baseflow to Streams ..........................................................103 
4.10.3  Hydrostratigraphy and Groundwater Flow ................................................................103 
4.10.4  CSG Depressurisation .................................................................................................105 
4.11  Data Limitations ............................................................................................. 106 
5 Environmental Values ........................................................................................ 107 
5.1  Groundwater Environmental Values Assessment ...................................... 107 
5.1.1  Biological Integrity of a Pristine or Modified Aquatic Ecosystem ..........................107 
5.1.2  Suitability for recreational use (primary recreation) ................................................109 
5.1.3  Suitability for Minimal Treatment before Supply as Drinking Water ......................110 
5.1.4  Suitability for Primary Industry Use ...........................................................................110 
5.1.5  Maintenance of Cultural and Spiritual Values ...........................................................110 
5.2  Summary of Project Scale Groundwater Environmental Values ............... 111 
6 Project Description and Activities .................................................................... 114 
6.1  Introduction .................................................................................................... 114 
6.2  Project Development Area ............................................................................ 114 
6.3  Project Facilities ............................................................................................ 114 
6.4  Wells ................................................................................................................ 114 
6.4.1  Exploration ...................................................................................................................115 
6.4.2  Production Wells ..........................................................................................................115 
42626960/1/E iii
Groundwater Impact Assessment - Bowen Gas Project
Table of Contents
6.4.3  Well Heads ....................................................................................................................116 
6.4.4  Grid Pattern ..................................................................................................................116 
6.4.5  Multi Seam Hydraulic Stimulated Vertical Wells ......................................................116 
6.4.6  Hydraulic Stimulation Fluids ......................................................................................116 
6.4.7  Other Well Designs ......................................................................................................117 
6.4.8  Gas and Water Gathering Systems ............................................................................117 
6.5  Preliminary Field Layout ............................................................................... 117 
6.6  Preliminary Field Schedule ........................................................................... 118 
6.7  Associated Water Production Forecast ....................................................... 118 
6.8  Preliminary Water Quality Forecast ............................................................. 119 
6.9  Associated Water Management Strategy .................................................... 120 
6.9.1  Deep Aquifer Injection .................................................................................................121 
6.9.2  Waterway Discharge ....................................................................................................123 
6.9.3  Substitution ..................................................................................................................123 
6.9.4  Brine and Salt Management ........................................................................................124 
7 Groundwater Model ............................................................................................ 125 
7.1  Introduction .................................................................................................... 125 
7.2  Aims ................................................................................................................ 125 
7.3  Model Development ....................................................................................... 125 
7.3.1  Software ........................................................................................................................125 
7.3.2  Domain and Grid Design .............................................................................................125 
7.3.3  Parameterisation ..........................................................................................................125 
7.3.4  Simplifying Assumptions of Single-Phase Flow ......................................................126 
7.3.5  Boundary Conditions ..................................................................................................127 
7.4  Model Calibration ........................................................................................... 128 
7.4.1  Steady-State Calibration Targets ...............................................................................128 
7.4.2  Steady-State Calibration .............................................................................................128 
7.4.3  Transition Calibration Targets ....................................................................................129 
7.4.4  Transient Calibration ...................................................................................................129 
7.5  Model Predictions .......................................................................................... 129 
7.5.1  CSG Production Scenario ...........................................................................................129 
7.5.2  Drawdown Predictions at the End of Development .................................................131 
42626960/1/E iv
Groundwater Impact Assessment - Bowen Gas Project
Table of Contents
7.5.3  Drawdown Predictions at the 50 Years Post-Development .....................................136 
7.5.4  Sensitivity of Drawdown to Major Faults ...................................................................136 
7.6  Model Comments ........................................................................................... 136 
8 Potential Impacts ................................................................................................ 142 
8.1  Introduction .................................................................................................... 142 
8.2  Potential Impact Area .................................................................................... 142 
8.3  Direct Impacts of Coal Seam Depressurisation .......................................... 147 
8.3.1  Deep Aquifers ...............................................................................................................147 
8.4  Indirect Impacts Resulting from Coal Seam Depressurisation ................. 148 
8.4.1  Shallow Aquifers ..........................................................................................................148 
8.4.2  Intermediate Aquifers in the North .............................................................................148 
8.4.3  Springs to the Southeast ............................................................................................149 
8.4.4  Faults and Folds ..........................................................................................................150 
8.4.5  Land Subsidence .........................................................................................................150 
8.4.6  Subsidence in Coal Formations .................................................................................150 
8.4.7  Overburden Compaction .............................................................................................152 
8.4.8  Summary .......................................................................................................................152 
8.5  Field Development and Operational Impacts .............................................. 153 
8.5.1  CSG field Development and other Sub-surface Activities .......................................153 
8.5.2  Hydraulic Stimulation ..................................................................................................153 
8.5.3  Induced Seismicity ......................................................................................................155 
8.5.4  Water Storage, Infrastructure, Processing and Distribution Impacts ....................156 
8.5.5  Associated Water Impacts ..........................................................................................156 
8.6  Cumulative Impacts ....................................................................................... 157 
8.6.1  Coal Mining in the Bowen Basin ................................................................................157 
8.6.2  CSG Production in the Surat Basin ...........................................................................157 
8.6.3  Groundwater Users in the Bowen Basin ...................................................................158 
8.7  Impacts Post-Closure and Recovery ........................................................... 158 
9 Significance Assessment and Impact Mitigation ............................................. 159 
9.1  Approach ........................................................................................................ 159 
9.1.1  Significance Assessment - Groundwater ..................................................................159 
9.1.2  Impact Mitigation .........................................................................................................159 
42626960/1/E v
Groundwater Impact Assessment - Bowen Gas Project
Table of Contents
9.2  Sensitivity Classification of Environmental Values .................................... 161 
9.2.1  Assumptions and Constraints ....................................................................................161 
9.2.2  Overall Sensitivity Evaluation of Groundwater.........................................................163 
9.2.3  Alluvium .......................................................................................................................163 
9.2.4  Basalt ...........................................................................................................................163 
9.2.5  Clematis Sandstone ..................................................................................................164 
9.2.6  Target Coal Seams .......................................................................................................164 
9.3  Significance Assessment Methodology ...................................................... 166 
9.3.1  Sensitivity Rating and Impact Magnitude Rating .....................................................166 
9.3.2  Impact Significance Interpretation .............................................................................167 
9.4  Impact Mitigation ........................................................................................... 168 
9.4.1  Mitigation of Fault-Related Impacts ...........................................................................168 
9.4.2  Mitigation of Coal Seam Depressurisation Impacts .................................................168 
9.4.3  Legislation Requirements ...........................................................................................169 
9.4.4  Trigger Action Water Bores ........................................................................................170 
9.4.5  Mitigation of Project Development Impacts ..............................................................171 
9.4.6  Mitigation of Associated Water Management Impacts ............................................171 
9.5  Impact Mitigation and Residual Impacts ..................................................... 172 
9.6  Environmental Constraints ........................................................................... 182 
10 Monitoring and Commitment Management .................................................... 183 
10.1  Groundwater Monitoring Objectives ............................................................ 183 
10.2  Groundwater Baseline and Impact Monitoring ........................................... 183 
10.2.1  Environmental Protection Measures .........................................................................183 
10.2.2  Regional Baseline Monitoring ....................................................................................184 
10.2.3  Numerical Groundwater Model ...................................................................................184 
10.2.4  Trigger Actions for ‘At-Risk’ Bores ............................................................................184 
10.2.5  Hydraulic Stimulation ..................................................................................................185 
10.2.6  Regional Impact Monitoring........................................................................................186 
10.2.7  Groundwater Monitoring Plan Phase 1 ......................................................................186 
10.2.8  Site Impact Monitoring ................................................................................................186 
10.3  Response Requirements ............................................................................... 187 
10.4  Beneficial Use and Associated Water .......................................................... 188 
42626960/1/E vi
Groundwater Impact Assessment - Bowen Gas Project
Table of Contents
10.5  Data Management and Reporting Requirements ........................................ 188 
10.6  Cumulative Impacts ....................................................................................... 189 
10.6.1  Cumulative Groundwater Drawdown .........................................................................189 
10.6.2  Cumulative Groundwater contamination ..................................................................189 
11 Reference .......................................................................................................... 190 
12 Limitations ........................................................................................................ 197 
12.1  Geotechnical and Hydro Geological Report ................................................ 197 

Tables
Table 1-1  Terms of Reference (ToR) Summary Table ..................................................................... 4 
Table 1-2  Summary of Relevant Policies, Guidelines and Legislation to the Project Area .............. 8 
Table 2-1  Phases of Work Undertaken During the Groundwater Impact Assessment ................... 19 
Table 2-2  Key Reports Considered During the Groundwater Impact Assessment ........................ 21 
Table 3-1  Regional Stratigraphy ..................................................................................................... 28 
Table 3-2  Permian Coal Seams and current Project CSG Target Seams ...................................... 33 
Table 4-1  NRM Registered Bores in the Study Area with Reported Water Level Data .................. 40 
Table 4-2  NRM Bores Registered in the Project Area with Reported Water Level Data ................ 40 
Table 4-3  Hydrostratigraphy of the Project Study Area .................................................................. 42 
Table 4-4  Hydrostratigraphy of the Project Area and Initial Estimates of Hydraulic Properties ...... 53 
Table 4-5  Summary of average recorded groundwater levels in the Study area ........................... 54 
Table 4-6  Groundwater Salinity Classification (adapted from Hem, 1985) ..................................... 71 
Table 4-7  Tolerances for drinking and domestic water (adapted from NHMRC and NRMMC, 2011)
........................................................................................................................................ 71 
Table 4-8  Tolerances of Livestock to Drinking Water Salinity (adapted from ANZECC and
ARMCANZ, 2000) ........................................................................................................... 72 
Table 4-9  Tolerances of Crops to Salinity of Irrigation Water (adapted from ANZECC and
ARMCANZ, 2000) ........................................................................................................... 72 
Table 4-10  Groundwater Quality Zones in the Study Area (adapted from Raymond and McNeil,
2011) ............................................................................................................................... 73 
Table 4-11  Summary of Groundwater Salinity and pH of Major Aquifer Units in the Isaac-Connors
and Mackenzie Sub-catchments (data reproduced from Pearce and Hansen, 2006).... 75 
Table 4-12  Summary of Groundwater Quality in Shallow Private Bores near Moranbah (aquifer units
are undefined) ................................................................................................................. 77 
Table 4-13  Summary of Groundwater Quality in the Undefined Tertiary and Duaringa Formations in
the Project Area (NRM bores) ........................................................................................ 78 
42626960/1/E vii