Forrestfield Airport Link Project Stage 2 Geotechnical Investigation Groundwater Conditions Report Prepared by: Golder Associates Pty Ltd FAL Document Number: FAL-PTAWA-GE-RPT-00009 May 2015 CONFIDENTIAL Version control Version No. Date Document Prepared By Endorsed By Status A 17/04/2015 Draft Golder Associates Pty Eric Hudson-Smith Ltd 0 26/05/2015 Final Golder Associates Pty Eric Hudson-Smith Ltd Approvals The signatures below certify that this report has been reviewed, endorsed and approved, and that the signatories are aware of all the requirements contained herein and are committed to ensuring their provision. Reviewed ………………………………………………Signature Date Dave Thomas Delivery Manager Approved ………………………………………………Signature Date Ray Seman Project Director 2 Forrestfield Airport Link: Stage 2 Geotechnical Investigation, Groundwater Conditions Report| May 2015 May 2015 FORRESTFIELD-AIRPORT LINK PROJECT, STAGE 2 GEOTECHNICAL INVESTIGATION Groundwater Conditions Report FOR INFORMATION Submitted to: Public Transport Authority Public Transport Centre West Parade PERTH WA 6000 T R O P E Report Number. 147642129-077-R-Rev0 R Distribution: 2 Copies - Public Transport Authority 1 Copy - Golder Associates Pty Ltd FAL STAGE 2 GI – GROUNDWATER CONDITIONS REPORT Record of Revision Company Client Contact Revision Description Date Issued PTA Mary Durkan A Draft issued for client review 17/04/2015 PTA Mary Durkan 0 Final issued for use 26/05/2015 May 2015 Report No. 147642129-077-R-Rev0 FAL STAGE 2 GI – GROUNDWATER CONDITIONS REPORT Table of Contents 1.0 INTRODUCTION ........................................................................................................................................................ 1 1.1 Related Reports ............................................................................................................................................ 1 2.0 PROJECT BACKGROUND ....................................................................................................................................... 2 3.0 OBJECTIVES ............................................................................................................................................................ 2 4.0 SITE DESCRIPTION .................................................................................................................................................. 3 4.1 Topography and Surface Features ............................................................................................................... 3 4.2 Climate ......................................................................................................................................................... 4 4.3 Geology ........................................................................................................................................................ 4 5.0 HYDROGEOLOGICAL CONDITIONS ....................................................................................................................... 6 5.1 Definitions ..................................................................................................................................................... 6 5.2 Assignment of Hydrogeological Units ........................................................................................................... 6 5.2.1 West Zone ............................................................................................................................................... 7 5.2.2 East Zone ................................................................................................................................................ 7 5.3 Groundwater Levels ...................................................................................................................................... 7 5.3.1 Published Information ............................................................................................................................. 7 5.3.2 Historical Trends ..................................................................................................................................... 7 5.3.3 Seasonal Fluctuations ............................................................................................................................. 8 5.3.4 March 2015 Levels .................................................................................................................................. 8 5.3.5 Multi Aquifer System (West Zone)........................................................................................................... 9 5.3.6 Perched Groundwater Levels .................................................................................................................. 9 5.3.6.1 West Zone ........................................................................................................................................... 9 5.3.6.2 East Zone ............................................................................................................................................ 9 5.4 Groundwater Recharge .............................................................................................................................. 10 5.5 Groundwater Discharge .............................................................................................................................. 10 5.5.1 Surface Water ....................................................................................................................................... 10 5.5.2 Drains .................................................................................................................................................... 10 5.5.3 Local Groundwater Users ..................................................................................................................... 11 5.6 Groundwater Flow ...................................................................................................................................... 11 5.7 Hydraulic Properties ................................................................................................................................... 12 5.7.1 Transmissivity ....................................................................................................................................... 12 5.7.2 Hydraulic Conductivity ........................................................................................................................... 13 5.7.3 Storage Coefficient................................................................................................................................ 13 May 2015 Report No. 147642129-077-R-Rev0 i FAL STAGE 2 GI – GROUNDWATER CONDITIONS REPORT 5.8 Groundwater Quality ................................................................................................................................... 16 6.0 DEWATERING ......................................................................................................................................................... 17 6.1 Dewatering Requirements .......................................................................................................................... 17 6.2 Dewatering Methodology ............................................................................................................................ 19 6.3 Groundwater Modelling ............................................................................................................................... 19 6.3.1 Groundwater Modelling ......................................................................................................................... 19 6.3.2 Model Scenario Runs ............................................................................................................................ 20 6.4 Dewatering Rates ....................................................................................................................................... 21 6.5 Effects of Dewatering .................................................................................................................................. 22 6.5.1 Groundwater Quality ............................................................................................................................. 23 6.5.2 Surface Water ....................................................................................................................................... 23 6.5.3 Means of Reducing Effects ................................................................................................................... 23 6.6 Dewatering Disposal Options...................................................................................................................... 24 6.6.1 Recharge Wells ..................................................................................................................................... 24 6.6.2 Reuse on Site ....................................................................................................................................... 24 6.6.3 Infiltration .............................................................................................................................................. 24 6.6.4 Stormwater System ............................................................................................................................... 25 6.6.5 Sewer .................................................................................................................................................... 25 7.0 DESIGN GROUNDWATER LEVELS (50 AND 120 YEAR) ..................................................................................... 26 7.1 Methodology ............................................................................................................................................... 26 7.1.1 Key Parameters .................................................................................................................................... 26 7.1.2 Design Groundwater Level Estimation .................................................................................................. 27 7.1.2.1 50 Year Design Groundwater Levels ................................................................................................. 27 7.1.2.2 120 Year Design Groundwater Levels ............................................................................................... 28 7.2 Design Groundwater Level ......................................................................................................................... 29 7.2.1 Perched Aquifer at Forrestfield ............................................................................................................. 29 7.3 Risks Associated with Design Groundwater Levels .................................................................................... 30 7.4 Drainage Control ......................................................................................................................................... 30 8.0 INFILTRATION CAPACITY ..................................................................................................................................... 31 9.0 KEY HYDROGEOLOGICAL CHARACTERISTICS AND CONSIDERATIONS ....................................................... 33 9.1 Bayswater Dive Structure ........................................................................................................................... 33 9.2 Airport West Station .................................................................................................................................... 33 9.3 Consolidated Airport Terminal Station ........................................................................................................ 34 9.4 Forrestfield Area ......................................................................................................................................... 35 May 2015 Report No. 147642129-077-R-Rev0 ii FAL STAGE 2 GI – GROUNDWATER CONDITIONS REPORT 10.0 RECOMMENDATIONS FOR FURTHER WORK ..................................................................................................... 35 11.0 REFERENCES ......................................................................................................................................................... 36 12.0 LIMITATIONS .......................................................................................................................................................... 39 TABLES Table 1: Summary of Project Specific Geological Units ...................................................................................................... 5 Table 2: Summary of Project Specific Hydrogeological Units .............................................................................................. 6 Table 3: Transmissivity Values from the Pumping Test Analysis ...................................................................................... 13 Table 4a: Summary of Horizontal Hydraulic Conductivities by Hydrogeological Unit (m/d) ............................................... 14 Table 4b: Summary of Horizontal Hydraulic Conductivities by Hydrogeological Unit (x10-5 m/s) ...................................... 15 Table 5: Construction Details and Dewatering Requirements ........................................................................................... 17 Table 6: Model Scenarios. ................................................................................................................................................. 20 Table 7: Modelled Dewatering Rates and Volume ............................................................................................................ 21 Table 8: Modelled Extent of Groundwater Level Drawdown (m) ....................................................................................... 22 Table 9: 50 and 120 Year Design Groundwater Levels ..................................................................................................... 29 Table 10: Infiltration Test Results ...................................................................................................................................... 32 FIGURES (WITHIN REPORT) Sketch A: Forrestfield-Airport Link Project - Golder Report Series Breakdown. This report is shown coloured and other reports in the series are shown in grey. .................................................................................................... 1 Sketch B: Annual Rainfall from 1945-2014 (BOM ID 9021 – Perth Airport)......................................................................... 4 FIGURES (FOLLOWING REPORT) Figure 1: General Site Location Plan Figure 2: Conceptual Geological Model and Relationship Diagram Figure 3: Conceptual Hydrogeological Model Figure 4: Publicly Available Water Data Figure 5: March 2015 Groundwater Levels – Map book Figure 6A: Groundwater Level Drawdown Contours – Plan View for Upper Aquifer. Scenario 1A and 1B: Bayswater Dive Structure (16 Weeks) Figure 6B: Groundwater Drawdown Contours – Cross Section. Scenario 1A and 1B: Bayswater Dive Structure (16 Weeks) Figure 7A: Groundwater Drawdown Level Contours – Plan View. Scenario 2A: Airport West Station (52 Weeks) Figure 7B: Groundwater Drawdown Contours – Cross Section. Scenario 2A: Airport West Station (52 Weeks) Figure 8A: Groundwater Drawdown Level Contours – Plan View. Scenario 3A: Consolidated Airport Terminal Station (52 Weeks) Figure 8B: Groundwater Drawdown Contours – Cross Section. Scenario 3A: Consolidated Airport Terminal Station (52 Weeks) Figure 9A: Groundwater Drawdown Level Contours – Plan View. Scenario 3B: Consolidated Airport Terminal Station (52 Weeks) May 2015 Report No. 147642129-077-R-Rev0 iii FAL STAGE 2 GI – GROUNDWATER CONDITIONS REPORT Figure 9B: Groundwater Drawdown Contours – Cross Section. Scenario 3B: Consolidated Airport Terminal Station (52 Weeks) Figure 10A: Groundwater Level Drawdown Contours – Plan View. Scenario 4A: Forrestfield Dive Structure (16 Weeks) Figure 10B: Groundwater Drawdown Contours – Cross Section. Scenario 4A: Forrestfield Dive Structure (16 Weeks) Figure 11A: Groundwater Level Drawdown Contours – Plan View. Scenario 4B: Forrestfield Dive Structure (16 Weeks) Figure 11B: Groundwater Drawdown Contours – Cross Section. Scenario 4B: Forrestfield Dive Structure (16 Weeks) Figure 12: Long Section – 50 and 120 Year Design Groundwater Levels APPENDICES APPENDIX A Historical Hydrographs APPENDIX B March 2015 Groundwater Level Measurements APPENDIX C Summary of Analysis of PSD Samples APPENDIX D Summary of Slug Test Analysis APPENDIX E Summary of Test Pumping Analysis APPENDIX F Description of Preliminary Groundwater Model Setup APPENDIX G Summary of Analysis of Inverse Auger Hole Testing APPENDIX H Summary of Analysis of Infiltration Testing APPENDIX I Limitations May 2015 Report No. 147642129-077-R-Rev0 iv FAL STAGE 2 GI – GROUNDWATER CONDITIONS REPORT List of Abbreviations, Acronyms, Definitions and Units This list contains abbreviations, acronyms, definitions and units used on this project and in the complete Golder Associates Pty Ltd (Golder) Stage 2 geotechnical investigation report series. AASS Actual Acid Sulfate Soil AF Ascot Formation AFa Ascot Formation – Ascot Beds AFj Ascot Formation – Jandakot Beds a Peak horizontal ground acceleration h AHD Australian Height Datum AS Australian Standard ASS Acid Sulfate Soil ASTM American Society for Testing and Materials ATV Acoustic Televiewer AWS Airport West Station bgl below ground level BH Borehole BS Bassendean Sand CaCO Calcium carbonate 3 CATS Consolidated Airport Terminal Station CBD Central Business District CBR California Bearing Ratio C Compression index c CERCHAR Laboratoire du Center d' Études et Recherches des Charbonnages de France, Abrasiveness Index CH Chainage CIU Consolidated, Isotropic and Undrained CP Cross Passage CPT Cone Penetration Test CPTU Piezocone Penetration Test C Recompression index r CRR Cyclic Resistance Ratio CRS Chromium Reducible Sulfur C Swelling index s CSR Cyclic Stress Ratio c Undrained shear strength (as shown on flat plate dilatometer test reports) = s u u DBYD Dial Before You Dig DCP Dynamic Cone Penetrometer DDR Dry Density Ratio DIRD Department of Infrastructure and Regional Development DMT, D Flat Plate Dilatometer DPR Drilling Parameter Recording May 2015 Report No. 147642129-077-R-Rev0 v FAL STAGE 2 GI – GROUNDWATER CONDITIONS REPORT E’ Drained Young’s modulus EA axial stiffness of tunnel lining EE Emergency Egress shaft EI bending stiffness of tunnel lining EPB Earth Pressure Balance E Equivalent rock Young’s modulus r ERI Electrical Resistivity Imaging FAL Forrestfield-Airport Link FFS Forrestfield Station F Liquefaction triggering factor L FR Friction Ratio (cone penetration testing) f Sleeve friction (cone penetration testing) s FWS Full Waveform Sonic G Small strain shear modulus 0 G Working-strain shear modulus GF Guildford Formation GPS Global Positioning System GS Gnangara Sand HA Hand Augered borehole HCl Hydrochloric acid IBC Intermediate Bulk Containers I Material index (flat plate dilatometer testing) D I Rigidity index = G/s r u I Point Load Strength Index (PLI) corrected to 50 mm diameter s50 ISSMGE International Society of Soil Mechanics and Geotechnical Engineering k hydraulic conductivity (in situ permeability) k horizontal hydraulic conductivity (permeability) h k vertical hydraulic conductivity (permeability) v k hydraulic conductivity (permeability) in the x direction in the model (= k ) x h k hydraulic conductivity (permeability) in the y direction in the model (= k ) y v K Coefficient of at-rest earth pressure 0 K Horizontal stress index (flat plate dilatometer testing) D LCPC Laboratoire des Ponts et Chaussées LG Gas monitoring well M Constrained modulus (flat plate dilatometer testing) MASW Multi-channel Analysis of Surface Waves MG Made Ground (Fill) MIS Marine Isotope Stage (palaeochannel reference) MMDD Maximum dry density/moisture content relationship using modified compactive effort MRWA Main Roads Western Australia MW Groundwater Monitoring Well NATA National Association of Testing Authorities, Australia NQ Drilling rod size with rod outside diameter = 69.9 mm OF Osborne Formation OFf Osborne Formation – Kardinya Shale Member fines dominated May 2015 Report No. 147642129-077-R-Rev0 vi