Technical Appendices Q6, Q7, R1, S1, T1, U1, V1 and W1

558 Pages·2010·9.73 MB·English

Technical Appendices
Q6, Q7, R1, S1, T1, U1, V1 and W1
Draft Environmental Impact
Statement/Environmental Review
and Management Programme for the
Proposed Wheatstone Project
July 2010
Wheatstone Project
Disclaimer
In preparing this Draft Environmental Impact Statement/Environmental Review
and Management Programme (Draft EIS/ERMP), Chevron Australia Pty Ltd
(Chevron) has relied on material provided by specialist consultants, government
agencies and other third parties who are identified in the Draft EIS/ERMP.
Chevron has not verified the accuracy or completeness of the material provided
by these consultants, government agencies and other third parties, except where
expressly acknowledged in the Draft EIS/ERMP. Should there be any difference
or inconsistency between the material presented in this Draft EIS/ERMP and
that in any third-party document referred to herein (including assessments,
findings, opinions, project descriptions, proposed management measures and
commitments), the material presented in the Draft EIS/ERMP alone shall be taken
to represent Chevron’s position.
Copyright Note
© 2010 Chevron Australia Pty Ltd. The information contained in this document is
the property of Chevron Australia Pty Ltd and may not be used or copied in whole
or part without its prior written consent.
Title: Draft Environmental Impact Statement/Environmental Review and Management
Programme for the Proposed Wheatstone Project: Technical Appendices Q6, Q7, R1, S1,
T1, U1, V1 and W1
Wheatstone Project Appendix O4 – A DesWchriepatitosnt oonf eM Pegroaj eFacut nAap Dpeisntrdiibxu Qti6o nto a Wnd1
Abundance in the SW Pilbara Using Aerial Surveys Mid Study Report December 2009
Appendix Q6 to W1
Q6 Project Wheatstone Ashburton River Flow and Discharges Study 2
Q7 Baseline Water Quality Assessment Report 72
R1 Desktop Study of Marine Biosecurity in the Wheatstone Project Area 120
S1 Draft Dredging and Spoil Disposal Management Plan 180
T1 Draft Coastal Processes Management Plan 294
U1 Draft Construction Environmental Management Plan 358
V1 Archaeological and Historical Survey Report 478
W1 DEWHA and EPA Requirements by Chapter 536
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Appendix Q6
Wheatstone Project Ashburton River Flow
and Discharges Study
Wheatstone Project Appendix Q6 - Wheatstone Project Ashburton River Flow and Discharges Study
1 Introduction 11
1.1 Background and Objectives 11
1.2 History of Sediment Discharge at Onslow Port 12
1.3 Suspended Sediment and Nutrient Loads in Rivers 12
1.3.1 Sediment Transport Curves 13
1.3.2 Suspended Sediment Sampling in Rivers
in North West Western Australia 13
2 Data Review 15
2.1 Geology 15
2.2 Landuse 15
2.3 Climate 15
2.4 Water Quality 17
2.5 Surface Water Hydrology 18
2.6 Existing Flow Sediment and Dissolved Nutrient Data 18
3 Field Investigation 21
3.1 Sampling Site Locations 21
3.1.1 Total Suspended Solids and Turbidity Sampling 21
3.1.2 Flow Measurement 21
3.2 Methodology 21
3.2.1 Sample Collection 21
3.2.2 Sample Analysis 21
3.2.3 Ashburton River Flow Volumes 22
3.2.4 Sediment Transport Curve 23
4 Ashburton River Hydrology 25
4.1 Flow Volume 25
4.2 Frequency of Flooding 27
4.3 Flow Velocities 28
5 Dissolved Nutrients 29
5.1 Nitrogen and Phosphorus 29
6 Sediment Transport 31
6.1 Suspended Solids 31
6.2 Particle Size 31
6.3 Transport Curve 32
6.4 Sediment Discharge at Nanuturra 33
6.5 Sediment Discharge to Ocean 37
7 Conclusions and Recommendations 39
7.1 Conclusions 39
7.2 Limitations to Estimates of Total Suspended Solid
Discharging from the Ashburton River 39
8 References 41
9 Limitations 43
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Wheatstone Project Appendix Q6 - Wheatstone Project Ashburton River Flow and Discharges Study
Tables
Table 2-1 Monthly Rainfall Recorded at Onslow in 2009 16
Table 3-1 Summary of the Ashburton River Sampling Program 22
Table 4-1 Ashburton River Daily Flow Volumes and Sampling Dates 26
Table 5-1 Estimated Total Annual Nitrogen and Phosphorus Discharges from the Ashburton River –
Based on Daily Flow Measurements 30
Table 6-1 Measured Total Suspended Solids and Turbidity in 2009 31
Table 6-2 Particle Size in 2009 Water Samples 32
Table 6-3 Estimated Total Annual Sediment Load at Nanuturra Bridge (based on daily flow) 37
Table E-1 Total Suspended Solids Data from API Sampling during January and February 2009
Charts
Chart 2-1 2009 and Long Term Average Monthly Rainfall at Onslow 17
Chart 4-1 Annual Flow Volumes in the Ashburton River (1973-2008) 25
Chart 4-2 Total Daily Flow in the Ashburton River (January to April 2009) 26
Chart 4-3 Flood Frequency Analysis for the Ashburton River 27
Chart 5-1 Relationship between total nitrogen levels and flow rates between 1973 and 2008
in the Ashburton River 29
Chart 5-2 Relationship between phosphorus levels and flow rates between 1973 and 2008
in the Ashburton River 30
Chart 6-1 Concentration of Total Suspended Solids as a Function of Daily River Water Discharge
in the Ashburton River at Nanuturra Bridge 34
Chart 6-2 Estimated Annual Total Suspended Solids Load in the Ashburton River at Nanuturra Bridge
over a 37 year period (based on daily flow) 35
Chart 6-3 Comparison of Turbidity and Flow Rate in the Ashburton River 36
Plates
Plate D-1 Fortescue River during dry conditions, and in flood following a heavy rainfall
event from Cyclone Dominic in January 2009
Plate D-2 Ashburton River at Nanuturra Bridge in May 2009 and February 2009
Plate D-3 Ashburton River 5km upstream of Ashburton Delta
Plate D-4 Ashburton River Mouth/Estuary
Appendices
Appendix A ALS Laboratory Results
Appendix B Particle Size Analysis Data
Appendix C Chain of Custody Forms
Appendix D Site Photographs
Appendix E API Sampling
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Wheatstone Project Appendix Q6 - Wheatstone Project Ashburton River Flow and Discharges Study

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Wheatstone Project Appendix Q6 - Wheatstone Project Ashburton River Flow and Discharges Study

Report
Project Wheatstone Ashburton River Flow and
Discharges Study

5 MAY 2010
Prepared for
Chevron Australia Pty Ltd
QV1, 250 St Georges Terrace
Perth, Western Australia, 6000
42907466

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Wheatstone Project Appendix Q6 - Wheatstone Project Ashburton River Flow and Discharges Study

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