Western Basin Dredging & Disposal EIS Supplementary Information ...

Contents1. Introduction 1-11.1 Project Background 1-11.2 EIS Submissions Summary 1-22. Legislation and Approvals 2-82.1 Legislation 2-82.2 Approvals Timing 2-92.3 Mining Approvals 2-92.4 Planning 2-92.5 DERM Approvals 2-103. Project Alternatives and Options Assessments 3-123.1 Submissions on Project Alternatives 3-123.2 Background 3-133.3 Response to Submissions 3-134. Project Form – Reclamation Design and Filling 4-174.1 Description of Project 4-174.2 Filling of Reclamation 4-204.3 Description of Harbour 4-214.4 Stormwater Management 4-225. Dredging Methodology 5-265.1 Submission Overview 5-265.2 Background 5-275.3 Response to Submissions 5-285.4 Dredging Methodology 5-285.5 Dredge Volumes 5-316. Hydrodynamic Modelling 6-406.1 Hydrodynamic Model 6-406.2 Wave Model 6-406.3 Combined Storm Surge, Tide and Wave Set-Up Modelling 6-436.4 Sediment Transport 6-4342/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document

6.5 Discussion of Results 6-436.6 Report Structure 6-446.7 Model Review 6-447. Mud Wave, Scour and Resuspension 7-457.1 Overview 7-457.2 Mud Wave 7-457.3 Construction Sequencing and Scour 7-517.4 Mitigation Measures 7-537.5 Resuspension 7-547.6 Potential of Fate Resuspended Dredge Material 7-557.7 Mud Wave Fate 7-597.8 TSS Source Fluxes 7-608. Turbidity Duration and Water Quality 8-618.1 Overview 8-618.2 Water Quality Objectives 8-618.3 Decant 8-668.4 Tidal Channel 8-678.5 Elutriates and Sediment Quality 8-689. Dredging Water Quality 9-729.1 Turbidity Impacts 9-729.2 Impacts to Underwater Light Climate 9-779.3 Other Issues 9-7810. Ecological Impacts 10-8010.1 Benthic Habitat Impacts 10-8010.2 Marine Threatened Species 10-9310.3 Cumulative Impacts 10-10410.4 Migratory Birds 10-10610.5 Mitigation of Impacts and Habitat Offsets 10-10810.6 Terrestrial Habitat 10-11010.7 Risk Assessment 10-11110.8 Biosecurity (Weed and Pest Management) 10-11210.9 Other Matters 10-11411. Fisheries 11-11542/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document

11.1 Impacts on Habitat 11-11511.2 Compensation/Offsets 11-11612. Offset Policy 12-11812.1 Offsets Strategy 12-11812.2 Fisheries Compensation 12-11912.3 Kangaroo Island Airport 12-12013. Acid Sulfate Soils 13-12113.1 Bund Construction 13-12113.2 ASS Mapping 13-12113.3 ASS Occurrence and Sampling 13-12213.4 ASS Management 13-12814. Traffic 14-13114.1 Marine Traffic 14-13114.2 Land-based Traffic 14-13115. Social and Cultural Impact 15-13315.1 Consultation 15-13315.2 Fishermen Numbers 15-13315.3 Social Impact Assessment and Significance Ratings 15-13415.4 Indigenous Employment 15-13415.5 Compensation to Commercial Fishermen 15-13415.6 Recreational Access and Exclusion Zones 15-13516. Bund Construction 16-13816.1 Description of Proposed 24/7 Works 16-13816.2 Noise 16-14016.3 Traffic 16-14316.4 Terrestrial Fauna 16-14616.5 Marine Fauna 16-14817. Management Measures 17-15217.1 Dredge Management Submissions 17-15217.2 Dredge Management Reponses 17-15317.3 Monitoring Programs 17-15417.4 Details of Dredge Monitoring Program 17-15542/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document

18. Rehandling and Offshore Disposal Option 18-15918.1 Overview 18-15918.2 Sediment Loading 18-15918.3 Ecological Implications 18-16319. Other 19-16819.1 Landscape and Visual Assessment 19-16819.2 Climate Change 19-16819.3 Temperature Inversions 19-16919.4 Groundwater 19-17019.5 Cost/Benefit Analysis 19-17019.6 Fossil Fuels 19-17119.7 Maritime Heritage 19-17119.8 Cumulative and Consequential Impacts 19-17219.9 Marine Incidents 19-17220. References 20-173Table IndexTable 1-1 Matrix of submissions and relevant chaptersaddressing issues 1-4Table 5-1 Dredging stages for the Western Basin Dredging andDisposal Project 5-31Table 5-2 Project timing 5-33Table 5-3 Indicative timing for each dredging scenario and stage5-33Table 5-4 Design of dredged areas for each dredging stage 5-37Table 5-5 Dredging methodology summary 5-38Table 7-1 Critical bed shear stress and dry mud density 7-48Table 7-2 Critical bed shear stress exceedance for Segments 6and 7 7-49Table 7-3 Analytical modelling of sediment fluxes for critical bedshear stress of 1.13 N/m 2 7-50Table 7-4 Sediment fluxes based on variations in dry muddensity 7-50Table 7-5 Description of modelled plume scenarios from Table 4-3 (WB EIS Volume 3, Appendix J) 7-56Table 7-6 TSS source fluxes 7-6042/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document

Table 8-1 PCBs limits of reporting 8-68Table 8-2 PAHs and phenol species and limits or reporting 8-69Table 8-3 PAHs and phenols at site 1A-063 8-69Table 8-4 Tidal currents 8-71Table 9-1 Comparison of 50 th , 20 th , 10 th and 5 th probabilityexceedance of TSS at key locations in The Narrowsfor each scenario with and without rehandling 9-76Table 9-2 Light impact summary for Scenarios 1A, 1B and 2 9-78Table 10-1 Areas of benthic habitat expected to be directly andindirectly impacted by construction and operationworks (based on data from GHD and DEEDI) 10-82Table 10-2 Cumulative seagrass habitat (ha, as measured byDEEDI) predicted to be affected by differing plumeconcentrations under dredge Scenarios 1A, 1B, 2 and3 10-85Table 10-3 Area of mapped seagrass and distance from ProjectArea 10-92Table 10-4 Predicted levels of impact from pile driving on marinespecies 10-96Table 13-1 PASS volume estimates for dredge stages 13-123Table 16-1 24/7 bund construction noise impacts 16-141Table 16-2 Project specific noise goals dB(A) from WB EIS 16-141Table 16-3 Standard construction noise and vibrationmanagement controls 16-143Table 16-4 Updated risk assessment for terrestrial flora and fauna16-148Table 16-5 Updated risk assessment for marine flora and fauna16-150Table 18-1 Number of sources and total mass flux of TSS perscenario without rehandling 18-161Table 18-2 Overview of dredge scenarios 18-162Table 18-3 Areas of seagrass (ha) under each plume contourpredicted to be affected by differing plumeconcentrations for dredge Scenarios 9 and 10 18-164Table 18-4 Comparison of dredge scenarios and predictedcumulative area of seagrass (ha) impact 18-16542/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document

Figure 13-4 Spatial plume TSS sedimentation (m/day) for theDECANT + FL CSD + FL TSHD (left panel) andDECANT + FL CSD + TC TSHD (right panel)scenarios 13-130Figure 15-1 Proposed maritime exclusion zones 15-137Figure 16-1 Haul road overall layout plan and control line setout16-139Figure 16-2 Nearest receiver (noise) locations 16-142Figure 18-1 Location of East Banks sea disposal site 18-160Figure 18-2 Seagrass areas affected by Scenario 9 dredge plume18-166Figure 18-3 Seagrass areas affected by Scenario 10 dredge plume18-167AppendicesA EIS Public SubmissionsB Modified Extreme Wave Conditions PlotsC Model ResultsD TSS and Light Impacts ReportE ASS Management FrameworkF ASS WB EIS FiguresG Borehole LogsH Additional ASS Laboratory ResultsI Traffic Analysis ReportJ Haul Route Options Study Extract42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document

1. IntroductionThe Western Basin Dredging and Disposal Environmental Impact Statement (WB EIS) concluded itsfive week public exhibition period in December 2009, with a total of 19 submissions received. ThisSupplementary Information document has been collated to address the issues raised, many of whichwere common to a number of submissions.1.1 Project BackgroundThe Gladstone Ports Corporation (GPC) proposes to undertake dredging associated with the deepeningand widening of existing channels and swing basins, and the creation of new channels, swing basinsand berth pockets in the Western Basin.Material dredged during the Western Basin development is proposed to be placed into a ReclamationArea to the north and immediately adjacent to the existing Fisherman’s Landing Reclamation Area. Theextended Fisherman’s Landing area will create a land reserve that will be used to service new portfacilities.The dredging of the Western Basin will occur in stages and the rate of both dredging and developmentwill be controlled by the demands of industry locating in the Gladstone region and requiring access toport facilities.An excerpt from the WB EIS (page 2-17) states that:The Western Basin Reclamation Area bund wall will be fully constructed prior to the commencement ofdredging. Should the Fisherman’s Landing Northern Expansion reclamation be approved under aseparate EIS process that is currently being undertaken, construction of a portion of that reclamationmay be undertaken prior to the approval and commencement of the Western Basin Reclamation Area.The Fisherman’s Landing Northern Expansion reclamation will therefore have the potential to containearly works material from one or more of the LNG facilities proposed for Curtis Island and the WesternBasin Reclamation can later be constructed around this initial portion of the Fisherman’s LandingNorthern Expansion.To enable the construction of the complete bund wall in one year, it is proposed to construct theWestern Basin Reclamation Area bund walls from three ‘fronts’. Two of these fronts start from theexisting Fisherman’s Landing reclamation, and a third starts from part way along the western bund wall.The third ‘front’ will be from the end of the off-road haul route to a portion of the western bund wall, withan at-grade crossing of what will be the intertidal channel constructed to enable this access. The atgradecrossing will need to be designed to minimise disruption to water flows during tidal movementsand will be removed upon completion of the bund wall construction.The development of Gladstone’s port facilities is considered a key part in the Central Queenslandtransport chain and an essential component of economic development for the region. Further industrialdevelopment in the region will support the growth of local industry, boost employment and build a strongand diversified regional economy.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document1-1

An Environmental Impact Statement (EIS) was completed on behalf of the GPC and the QueenslandState government. The EIS explored and assessed potential environmental, cultural, social andeconomic adverse and beneficial impacts and recommends approaches to manage these impacts.The five week public exhibition period ran from Monday November 16 to Friday December 18. A finaldecision on the EIS is expected in 2010.1.2 EIS Submissions SummaryFive of the 19 submissions were from government agencies (refer Table 1-1). Fourteen submissionswere from private or non-government organisations. The matrix in Table 1-1 shows in which chaptersissues have been addressed for each submission. Appendix A contains a copy of the EIS submissions.1.2.1 Key IssuesThe list below provides a summary of the main issues raised:Concern with respect to potential impacts on fisheries (whether commercial or recreational). Thecomments were centred on the loss of both habitat and access;Consideration of alternatives to the reclamation (i.e. the potential for land-based reclamation);Queries relating to the approvals process;Details of the proposed mitigation measures;Request for further information with respect to likely ecological impacts (in particular indirect impactsto seagrass and actual amount of seagrass affected);Details of the likely offsets program and evidence of GPC’s commitment to this program;Interaction with other industries (existing and proposed);Management of acid sulfate soils and their placement in the reclamation;Request for further information regarding the long term contribution to turbidity associated with thescour of mud around the reclamation;Water quality objectives for the reclamation decant; andDetails of proposed dredging methodology (including a number of comments with respect to theimpacts of rehandling).1.2.2 Responses to SubmissionsGiven the number of common themes, a consolidated approach has been adopted. Rather thanresponding to each individual submission separately (which would involve significant repetition ofresponses to issues), this document has been put together to address common issues that were raisedacross the submissions. These issues are dealt with in Chapters 2 to 18, with additional itemsaddressed in Chapter 19.Submissions that were not relevant to the Project or outside the scope of the SupplementaryInformation Document were not responded to.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document1-2

1.2.3 Additional InvestigationsAs part of reviewing the WB EIS, some additional options in relation to bund construction work hourshave been investigated. These are discussed in Section 16.Additional detail for management measures are provided in Chapter 17.In response to several submissions, GPC is also assessing the option of offshore disposal for a portionof the dredged material. This is discussed in Section 18.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document1-3

19 - OtherTable 1-1 Matrix of submissions and relevant chapters addressing issues•ChapterSubmission NoSubmitter2 – Legislation &Approvals3 – ProjectAlternatives &4 – Project Form –Reclamation Design5 – DredgingMethodology6 – HydrodynamicModelling7 – Mud Wave,Scour &8 – TurbidityDuration & Water9 – Dredging WaterQuality10 – EcologicalImpacts11 - Fisheries12 – Offset Policy13 – Acid SulfateSoils14 - Traffic15 – Social &Cultural Impact16 – BundConstruction17 – ManagementMeasures18 – Rehandlingand OffshoreDisposal Option1 Department ofTransport &Main Roads(DTMR)• • • •2 Department ofEnvironmentalResourcesManagement(DERM)• • • • • • • • • • •3 GladstoneRegionalCouncil• • • •4 Department ofEnvironmentWaterHeritage andthe Arts(DEWHA)• • • • • • • • • • •42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document•1-4

ChapterSubmission NoSubmitter2 – Legislation &Approvals3 – ProjectAlternatives &4 – Project Form –Reclamation Design5 – DredgingMethodology6 – HydrodynamicModelling7 – Mud Wave,Scour &8 – TurbidityDuration & Water9 – Dredging WaterQuality10 – EcologicalImpacts11 - Fisheries12 – Offset Policy13 – Acid SulfateSoils14 - Traffic15 – Social &Cultural Impact16 – BundConstruction17 – ManagementMeasures18 – Rehandlingand OffshoreDisposal Option19 - Other5 Coffey NaturalSystems (forShell CSG(Australia) PtyLtd)• • •6 QueenslandSeafoodIndustryAssociation• • • •7 Wiggins IslandCoal ExportTerminal PtyLtd (WICET)•8 AustraliaPacific LNG •9 GLNG/Santos-Petronas10 QER Group •11 Fitzroy BasinAssociation • • • • • • • • • •42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document1-5

19 - OtherChapterSubmission NoSubmitter2 – Legislation &Approvals3 – ProjectAlternatives &4 – Project Form –Reclamation Design5 – DredgingMethodology6 – HydrodynamicModelling7 – Mud Wave,Scour &8 – TurbidityDuration & Water9 – Dredging WaterQuality10 – EcologicalImpacts11 - Fisheries12 – Offset Policy13 – Acid SulfateSoils14 - Traffic15 – Social &Cultural Impact16 – BundConstruction17 – ManagementMeasures18 – Rehandlingand OffshoreDisposal Option12 CapricornConservationCouncil• • • • • • • • • •13 QGC/BG •14 Col DaleFishing • ••15 PrivateSubmitter,TannumSands•16 AJ & JLHolland • • • •17 PrivateSubmitter,Gladstone• •42/15386/400126•Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document1-6

2. Legislation and Approvals2.1 Legislation2.1.1 Submission #1 Figure 1-9 incorrectly lists the Transport Operations (Marine Pollution) Act as 1994.It is acknowledged that the correct year of the Act is 1995.2.1.2 Submission #1 No reference in the EIS as to how regional NRM targets (Resource Condition Targets ManagementAction Targets and Actions) of the Central Queensland Strategy for Sustainability (CQSS2) will beaddressed, delivered or impacted upon (I.e. if there will be any negative impacts to the achievementof NRM targets) as a result of the proposed activities of the Western Basin dredging project. Suggestthat relevant sections of the CQSS2 are addressed and relevant targets identified that will beimplemented or negated as a result of the Western Basin Dredging project.The CQSS2 was not referred to within the EIS as it was not a requirement of the Terms of Reference(ToR). The ToR stated that the EIS must describe and list Commonwealth, state and local legislation andpolicies relevant to the planning, approval, construction and operation of the Project. Never-the-less,some of the NRM targets in the CQSS2 are addressed within the EIS.2.1.3 Submission #4 Please note that the Environment Protection (Sea Dumping) Act 1981 does apply within threenautical miles of the coast in many circumstances, including at Gladstone. Any further discussion ofthe Act should reflect this point (see section 1.10.2-Commonwealth Legislation).Acknowledged, appropriate changes to the description of the legislation will be made with respect to anyfuture reference to the Act.2.1.4 Submission #12 Delete Table 1.8 as it is a misleading evaluation given the reclamation area is not within GladstoneState Development Area, therefore these comments are not relevant.Table 1.8 relates to the Gladstone State Development Area (GSDA) and is one of several planningpolicies that were reviewed as part of the EIS process. Whilst the proposed reclamation is not locatedwithin the GSDA, incorporation of the GSDA Development Scheme is appropriate as the site is situatedadjacent to the GSDA via the Material Transportation Services Corridor (MTSC), which is part of theGSDA.2.1.5 Submission #18 In relation to EPM3215, a 5 year renewal application was lodged in August 2008 and the EPM hassince been renewed with an expiry date of 31 December 2013.The new expiry date is acknowledged.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document2-8

2.2 Approvals Timing2.2.1 Submission #5The timing required to obtain operational works approval needs to be addressed in the indicativedredging program i.e., what lead times are required to obtain these approvals and how do they relateto the overall dredging program.Chapter 2 of the EIS describes the Project and provides indicative timeframes for both dredging andconstruction works. It should be noted that the approvals process sits outside of these indicativedredging dates, and relevant approvals will be obtained prior to the commencement of any dredging orconstruction activities.Approval timing for dredging approvals under the Environmental Protection Act 1994 and operationalworks (Tidal Works) under the Coastal Protection and Management Act 1995 are estimated to take aboutsix months to be processed through the Integrated Development Assessment System as describedunder the Sustainable Planning Act 2009, following finalisation of the Coordinator-General’s Report.This timeframe allows sufficient time to obtain owners consent from State Government Departments andthe four month legislative timeframe to be processed and assessed through the relevant regulatoryagencies such as the DERM and Queensland Fisheries.2.3 Mining Approvals2.3.1 Submission #10The Mining Approvals on the land associated with the Western Basin Dredging and Disposal Project areheld by QER, and relate to exploration and mineral development activities on the adjacent land and tidalareas around Fisherman’s Landing and are overlayed by the Project. Exploration Permit (Mineral) EPM3215 and Mineral Development Lease MDL 225 was issued to QER and has expiry dates of 31 stDecember 2013. The WB EIS considers that there may be some impacts on the Stuart Oil ShaleResources from the Western Basin Dredging and Disposal Project but the Project should still preservethe development of these petroleum resources in the surrounding areas.GPC approves of the suggestion that the Coordinator-General should issue a conditional requirement onGPC to consult with QER during the construction of the WB Project.2.4 Planning2.4.1 Submission #1The submission suggests to ensure the ongoing safety and efficiency of the state-controlled network,the department will require the amendment of the GPC Land Use Plan to include the Western BasinReclamation Area upon approval of the Coordinators General Report. The supplementary EIS shoulddetail the intentions of the GPC to amend the Land Use Plan, timing for this to occur, and detailsregarding the amendment to ensure all relevant stakeholders are referred proposed developmentapplications for the Reclamation Area.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document2-9

GPC will refer to the appropriate organisation, all properly made development applications which aretriggered under the Regulations in the Sustainable Planning Act 2009.GPC will amend its Land Use Plan to incorporate the Fisherman’s Landing Expansion area, prior to anynew land uses establishing on the newly developed area.2.5 DERM Approvals2.5.1 Submission #2Attachment 2 of Submission #2 contains recommended conditions of approval by the Coordinator-General (CG) relating to material change of use for Environmentally Relevant Activity 16 (extraction –dredging).Attachment 3 of Submission #2 contains recommended conditions of approval by the Coordinator-General (CG) relating to operational works (dredging and reclamation).Environmental approvals for dredging approvals under the Environmental Protection Act 1994 andoperational works (Tidal Works) under the Coastal Protection and Management Act 1995 will need to becompleted following finalisation and approval of the Coordinator-General’s Report. Further specificdetails (such as a Dredge Management Plan) of dredging operations and reclamation construction (asrequired for the granting of approvals) can be provided to DERM during the Sustainable Planning Act2009 approval process.It is recommended that the Coordinator-General approves both dredging and reclamation constructioncomponents of the Western Basin Dredging and Disposal Project EIS and incorporates the agreedrelevant conditions provided by DERM into the Coordinator-General’s Report. This process shouldinvolve a discussion of the recommended conditions provided by DERM in Attachment 2 and 3 of theirsubmission, with the potential for amended conditions arising from the additional information provided inthis supplementary information document (SID). In keeping with this, we note the following additionalinformation, which is expanded upon in subsequent sections of the SID.Attachment 2 (3.1): Dredging of the shipping berths and swing basin at Fisherman’s Landing must be carried out using acutter suction dredge, or a trailing suction hopper dredge operating without overflow with spoilpumped from the dredge to the reclamation area.Recent advice suggests that modern dredging equipment has significantly improved efficiency, and thatoverflow mode will only be required for very short periods of time when fine material is being dredged.Overflows are typically released below the waterline, as opposed to the older style dredgers whereoverflow was to the sea surface. Overflow dredging was proposed / required only for that period whenTSHD equipment is being used, with the period of overflow dependent on the type of dredging beingundertaken. Additional details are provided in Chapter 5. TSHD equipment would be used for no morethan 10% to 20% of the dredging operation. The material type is such that direct pumping of materialfrom the TSHD to the reclamation may not be possible, in which case either rehandling or offshoredisposal is required. Further detail is provided below,42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document2-10

Attachment 2 (3.2):Transfer the dredge spoil from trailing suction hopper dredges to the reclamation area shall beachieved by pumping direct from the dredges. Bottom dumping and subsequent dredging by cuttersuction dredge must not be used to transfer material to the reclamation area.Rehandling was nominated for that portion of the material to be dredged using TSHD, as the material isgenerally not conducive to being pumped directly into the reclamation (owing to proportion of clay andsilt), and that at the time of writing of the EIS, it was uncertain as to whether the existing offshoredisposal ground was accessible. It has since been determined that (a) sufficient capacity and access isavailable at the existing offshore spoil ground, and should use of this ground be approved, rehandlingwould most likely not be required. Refer to Chapter 18 for more details.Attachment 3 (1.4): A geofabric liner shall be applied to the internal side of the wall to minimise release of fine sedimentsfrom the reclamation area other than through the designated discharge point in accordance withspecified discharge limits.A geofabric liner has been proposed. It is also noted that there may be more than one discharge point.Whilst a single discharge point (at the NE corner of the reclamation) has been nominated for discharge ofthe CSD decant (i.e. during the dredging phase of the project), the concept design of the reclamationprovides for a discharge point (of treated stormwater) to the NW corner.Attachment 3 (1.5): Outer rock armour for the reclamation bund walls must be in place within 28 days of completion ofbund walls and not more than 50 metres of unprotected bund wall is to be exposed to prevailingwinds at any time.A distance of only 50 m may pose operational risks through machinery congestion at the constructionface. GPC would therefore propose discussion of a larger limit, which could be of the order of 75 to 100metres of unprotected bund wall.Attachment 3: A suitably designed barrier must be erected immediately seaward of the area of mangroves to becleared as part of the reclamation works such that sediment released during clearing is effectivelycontained.No mangroves are proposed to be cleared during construction of the Western Basin bund wall. However,clearing of a small area would have occurred in association with the FL153 reclamation.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document2-11

3. Project Alternatives and Options Assessments3.1 Submissions on Project AlternativesThis section addresses queries relating to the final form of the reclamation, and the consideration ofalternative disposal locations. Listed below are those submissions relating to the assessment of Projectalternatives.Submission #4 Further detailed consideration is required of alternative dredge disposal options, e.g. sea disposal,land disposal, combined sea/land disposal.Submission #14 This submission suggests that GPC should build a jetty instead of reclaiming land to retaincommercial fishing access.Submission #16 The submission suggests finding an alternative sediment disposal area to avoid impacts onrecreational fishing activities.Submission #5 The criteria used for the assessment of reclamation site options (Figure 1-6) should be listed anddescribed including how they were applied to the nominated options.Submission #12 Reconsider terrestrial (mainland) dumping sites within the Gladstone State Development Area.Submission #16 In terms of impacts on recreational fishing activities and impacts of activities on seagrass beds andmarine environment suggest find an alternative sediment disposal area.Submission #17 If a true environmental dis-benefits value is used then other disposal options become viable.Consider alternatives to spoil disposal, including on-land infill at Aldoga or government land.Submission #18 Fisheries Queensland could not support the reclamation component of the proposal on the basis ofinformation submitted within the EIS. Fisheries policies do not support the deposition of dredge spoilon tidal lands.Submission #18 A substantial assessment of alternative dredge spoil disposal options with lesser impacts is notprovided. Provide a detailed assessment of the process undertaken to identify suitable terrestrialsites, their suitability weightings and any considerations of using several terrestrial sites, or a reducedtidal lands site extending onto terrestrial land adjacent to Fisherman’s Landing.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document3-12

3.2 BackgroundThe Western Basin reclamation will adjoin the proposed Fisherman’s Landing Northern Extension(FLNE) reclamation. Should both be approved, a single Reclamation Area would result. The reasons forextending the reclamation to cover the larger area are therefore linked to the reasons for creating theFisherman’s Landing reclamation, as was described in the Supplementary Information Document forFLNE. A section of this justification is reproduced below.The FLNE EIS seeks approval for the construction of a reclamation bund to provide land to facilitate thefuture development of berths to service the adjacent GSDA area.It should be recognised that there is minimal land available immediately onshore of the proposedreclamation. A suitable area is required to support these future wharfs in a manner allowing the efficienthandling of materials. The existing land immediately adjacent to the proposed reclamation is eithersubject to a mining lease or currently owned and/or in use by industry. The reclamation as part of theFLNE is therefore critical for the future development of the port.Without the proposed reclamation being located adjacent to the shipping channel, the Port’s ability tohandle materials/products efficiently will be substantially restricted. That is, whilst the use of jettiedstructures may suit products such as coal, they will not allow the handling of all materials efficiently.3.3 Response to Submissions3.3.1 Use of Jetties for Western BasinWith the FLNE expansion in place, access to wharves will exist via the proposed land reclamation, andjetties are not proposed, as discussed above. The Western Basin reclamation will sit landward of theFLNE expansion, and is not for the purpose of providing any further wharves. Hence, the use of jetties isnot relevant to the Western Basin reclamation.3.3.2 Alternative Disposal Area OverviewThe options for disposal that existed comprised:Reclamation adjacent to FLNE;Reclamation at an alternative location;Land disposal; andOffshore disposal.The case for the use of extending the reclamation adjacent to FLNE in preference to the other threeoptions was addressed in Chapter 1 of the Western Basin EIS, with Table 1-4 providing a three pagediscussion. Figure 1-6 of the EIS also provided an overview as to why the reclamation took the shapethat has been proposed. The primary reasons are repeated below, with some additional reasoning alsoprovided.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document3-13

Reclamation at an Alternative LocationAlternate locations for reclamation could comprise terrestrial disposal (refer following section), or otherinter-tidal areas. Alternate inter-tidal areas were not favoured for the following reasons:A preference to limit impacts to one area within the harbour, rather than multiple areas. With a landbackedfacility already nominated for FLNE, part of the Western Basin will be impacted. It is thereforepreferable to not also impact other areas (e.g. the inter-tidal area to the south of the existingFisherman’s Landing).Utilising the area adjacent to FLNE will allow the use of the bund wall proposed for FNLE. This willresult in reduced bund wall construction than if a separate area were to be reclaimed elsewhere inthe harbour.Other areas that had been considered were not favoured in informal discussions with agencies (e.g.Hamilton Point) and North China Bay (Curtis Island coastline).The volume of material to be dredged. With potentially close to 45 million m 3 to be dredged, manyareas that might otherwise be considered were precluded. The Fisherman’s Landing/Western Basinarea offered the compromise solution of available space, existing reclamations, and the ability to fillto a greater height in order to reduce the overall footprint that would otherwise be required.Pumping distance: The Western Basin reclamation is closer to the point of dredging than many otheralternatives, and therefore represents a more feasible (and lower energy cost) solution.Land DisposalLand disposal was considered, but rejected on a number of fronts. These reasons include:Not preventing development of the Curtis Island Industry precinct – reclamations of up to 20 m inheight would inhibit the development of LNG plants, which then negates the purpose of the WesternBasin dredging.The Department of Infrastructure and Planning (DIP) has advised that suitable land is not availablewithin the Gladstone State Development Area (SDA), and that the placement of dredge materialwould potentially sterilise the land, preventing it from being developed in accordance with the SDA.DERM have indicated that Curtis Island is not considered an option for the disposal of dredgematerial.Pumping dredge material to land will suffer from the length of pumping distance involved, and theneed to maintain a network of pipes across the landscape for a period of several years.Saline run-off would present a significant management issue.Land disposal does not offer the opportunity to maintain any PASS material below water.Offshore DisposalAt the time of writing of the Western Basin EIS, offshore disposal was not an option on the basis of:Uncertainty as to whether any capacity remained in the port’s existing offshore spoil ground abovethat required for the maintenance dredging operation.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document3-14

Reluctance (anecdotal) of agencies such as the Great Barrier Reef Marie Park Authority for this to beconsidered.Project timing did not allow for sufficient time to consider the location and assessment of new spoilground locations.Knowledge that the volume of material to be dredged was considered too large for all material to beplaced offshore.Subsequent to the drafting of the EIS, GPC have completed survey of the spoil ground, and on the basisthat new equipment provides less requirement for the same vessel draught, it is now considered thatthere is at least 15 million m 3 available in the spoil ground.Coupled with the potential benefits that use of an offshore disposal option would appear to offer (i.e. asignificant reduction in the amount of rehandling required), offshore disposal is now considered a viableoption for a component of the dredging (e.g. up to 10 million m 3 ). This issue has been further explored,and is reported in Chapter 18.3.3.3 Reclamation Area Options (Figure 1.6)With the Western Basin site selected as the most suitable for reclamation, a number of different layoutoptions were considered. Submission #5 has requested additional detail as to the criteria used incomparing these options. These criteria are as follows:Land AttachmentWhere the reclamation touches the existing foreshore, much greater impacts are likely. These includeinterference with the groundwater regime, loss of mangrove areas, and the creation of barriers to existingstormwater runoff and creeks.Inter-tidal ExchangeThe area to the north of the Western Basin comprises some shallow areas with higher land elevationsthan the Western Basin tidal flats. This area, in the vicinity of Kangaroo Island and The Narrows is notcommonly inundated, but inundation can occur on the higher tides. The area is also understood to havecultural heritage values, and hence, it was seen to be of key importance to minimise impacts here wherepossible.Recreational AccessThe desire of the local community to retain access to as many areas as possible is well understood.Hence, those options that maximised the unaffected area, in terms of access, were ranked more highly.The preferred option provides the least restrictions to the Narrows, and to the northern part of theWestern Basin.Size of Seagrass Area AffectedThis criteria focuses on the footprint of the reclamation, as it affects seagrass areas.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document3-15

Land AccessOptions were considered in terms of the ease of access to the reclamation. The preferred option has thesmallest land area, and connects to an existing facility with existing access routes.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document3-16

4. Project Form – Reclamation Design and FillingThis chapter has been provided in response to queries relating to issues such as the final form andcapacity of the reclamation, design of the bund wall, management of stormwater, and how material willbe placed inside the reclamation. Alternate locations for the disposal of material were discussed in theprecious chapter, whilst questions pertaining to dredging are dealt with in the following chapter.4.1 Description of Project4.1.1 Liaison with Regional Harbour MasterSubmission #1 The submission suggests the proponent should liaise with the Regional Harbour Master (Gladstone)to ensure that there is consistency between the dredging requirements being quoted in all EIS’s forthe expansion of the Port of Gladstone.GPC confirms that they will carry out all dredging associated with the creation of channels, swing basins,berth pockets and MOF’s. GPC will, as matter of course, liaise with the Regional Harbour Master inregards to all matters associated with Port operations.4.1.2 Reclamation CapacityRefer also to Section 4.2.Submission #2The submission states the EIS has provided inadequate information to demonstrate that the WesternBasin reclamation area has the capacity to accommodate the volume of dredge spoil that may arisefrom all the possible port developments in the Western Basin together with adequate provisions forsettlement ponds. The area’s capacity needs to be demonstrated; if insufficient, the feasibility of offshoresea disposal of part, and/or relocation of treated spoil to a land disposal site should bepresented.The submission states that the Executive Summary indicates that the Fisherman’s Landing NorthernExpansion, with a footprint of 173.5 ha, is to accommodate 10 million m³ of dredge spoil. It seemsunlikely that the Western Basin Reclamation Area could accommodate over four times this volume,with a footprint of 235 ha as well as retain capacity for settling of drain water, even with a substantialmound as proposed. Dredge spoil from Options 1B, or 2A, or both and maintenance dredging spoilmay increase storage requirements.Submission #4 EIS addendum notes an additional 12 million cubic metres of spoil - further information is required oncapacity of reclamation site to take this material.The current reclamation proposal includes provision for a mound which provides the additional capacity.For a mound with a maximum height of 60 m, the net capacity is of the order of 55 Mm 3 . This allows a42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document4-17

deduction for perimeter bund walls, internal bund walls and capping layer volumes. It is most likely thatthe mound will not exceed 50 m in height. A 10 m reduction in height would result in a capacity loss ofless that 500,000m 3 . In the short-term, material placed inside the Reclamation Area may (in areas) beplaced higher than the final profile to allow for settlement of the material and for the retention of thenecessary settlement ponds.Following the completion of the dredging works, the interim settlement ponds will be reclaimed with thepreviously stockpiled material. It is accepted that some long-term “bulking “ of the dredged material willremain, and with an allowance of 15%, the effective capacity of the Reclamation Area is further reducedto 47 Mm 3 . The calculated ultimate capital dredge volumes are as follows as at time of writing (19 March2010):– Stage 1A (Curtis Is Proponents incl APLNG initial stages) 22.4 Mm 3– Stage 1B (incl all stages of GLNG LTD 5.3 Mm 3– Stages 2 & 3 10.0 Mm 3– Stage 4 (incl Hamilton Point and final LNG development) 4.6 Mm 3– Total Capital Dredge Volumes 42.3 Mm 34.1.3 APLNG Options Submission #2 (DERM 2.5) also notes there are compelling arguments in the EIS Addendum andfrom APLNG briefing that support option 2A for access to Laird Point. If this option is accepted, thereseems to be no justification for implementation of option 1B, given the master plan for the WesternBasin does not provide for further port development north of the proposed Fisherman’s LandingExtension.It is recognised that APLNG will not proceed with wharfs associated with the Addendum1B option.GPC has a desire to retain the option of extending the channel to the extent shown in the EIS as a longtermdevelopment option. GPC has no immediate plans to develop the channel north of the Fisherman’sLanding development. The intention of this EIS is to identify channels relevant to the ultimatedevelopment of the Western Basin (as currently envisaged).4.1.4 Extent of ReclamationSubmission #2 The submission suggests that the EIS offers little assessment of alternatives to disposal of spoil in thereclamation area such as sea disposal, land disposal, or a combination of options that could reducethe aerial extent of the reclamation area and therefore impacts on benthic communities. Table 1-4(Alternative Dredged Material Disposal Options within the Port of Gladstone) sets out options fordisposal that were considered, but there is no detailed comparison of the relative impact of feasibleoptions, especially sea dumping and partial removal of material from the reclamation area followinginitial draining. Information to support the position that the spoil material is unsuitable for anycommercial use is unconvincing and needs to be reviewed and justified.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document4-18

Confirm that the area shown on Figure E-1 is the full extent of the Western Basin Reclamation Areaand that it has adequate capacity to contain the full volume of spoil, with adequate provision for thesettlement of drain water prior to its discharge to meet limits consistent with maintaining the quality ofPort Curtis waters.In the event that the reclamation area does not have adequate capacity, the EIS should discuss thefeasibility of sea disposal of part of the dredge spoil and/or relocation of material from the reclamationarea to a land disposal area following draining.Further information in support of reclamation as opposed to other means of disposal were provided in theChapter 3. Since drafting of the EIS, the potential for offshore disposal of part of the volume of material tobe dredged has arisen, as discussed in Chapter 18. The use of offshore disposal (if permitted) willprovide benefits in terms of a reduced need for rehandling, and will reduce any concerns as to thecapacity of the reclamation. This is discussed further below.4.1.5 Internal BundsSubmission #2 Contingency planning for use of additional measures such as baffles or increased settlement pondvolume needs to be in place at the start of works to minimise the risk that dredging programs will beaffected.Construction of internal baffles/cells will be addressed in the DMP. At this stage and until the finaldredging programme is confirmed an internal cell layout cannot be provided. Internal bunds/cells will beprovided to meet the required water quality discharge conditions.4.1.6 Reclamation TerminologySubmission #12 Change the terminology of the reclamation area to reflect the nature of land use. The term‘reclamation’ implies this area will be reclaimed and used in some industrial form in the future. This isnot GPC’s intention. It is a dumping area for dredge spoil and terminology should reflect this.The combined FLNE and Western Basin Reclamation Area will support industrial use (predominantlyalong the eastern half of the reclamation). The balance of the area will support a “wetland” area, variouspotential transport corridors and a dredge spoil disposal area in the mound/hill area.4.1.7 Bund Wall CollapseSubmission #11Scouring at northern end of corner of reclamation requires further risk assessment and mitigationdecided in the event of bund wall collapse.The design of the rock bund allows for deformation over time, and the potential for collapse is low.Scouring has been considered as a potential source of turbidity and for its potential impact on the seabed(refer to Chapter 8), but further consideration in the WB EIS with respect to bund stability is not required.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document4-19

4.1.8 Bund AlignmentSubmission #11Identify …why the wall angles were selected to reduce the impact on natural ecological processes...Wall angles arise from two drivers: (1) continuation of the FLNE alignment, which is required toaccommodate wharves, and (2) a desire to minimise the footprint, and to not have walls attaching to theshoreline along the western edge.Submission #12 Suggest the width of the intertidal channel to the rear of the reclamation area be increased..A 40m width has been retained, which will allow tidal exchange to continue to occur. IN addition, DEMRhave suggested that the creation of ponds within the intertidal channel be avoided, in order to keepflushing characteristics similar to existing.4.2 Filling of Reclamation4.2.1 Reclamation CapacityThe net capacity of the Reclamation Area, excluding bunds (both internal and external) and cappingrequirements, is of the order of 55Mm 3 .Current (March 2010) capital dredge volume estimates for the total Western Basin Project are 42Mm 3 .Given that the Western Basin development will occur over a period in excess of 15 years, an allowancefor bulking of 15% is considered conservative. Therefore, the dredge volume including bulking isapproximately 48Mm 3 .Final capital dredge volumes are likely to be significantly less than 42Mm 3 as a consequence of thepotential offshore disposal of up to 10Mm 3 , and the possibility that not all five LNG proponents willproceed with their respective projects.4.2.2 Placement of PASS materialThe capacity within the reclamation for underwater storage (i.e. below MSL) is approximately 7.5Mm 3 .Previous dredging projects in the area deposited material in the adjoining Fisherman’s LandingReclamation Area. No treatment of the material was required and testing has indicated that no aciddischarge exceedances have occurred.3D Mapping of PASS materialIt is proposed to map the locations of PASS material to allow targeting of material to facilitate placementof material within the Reclamation Area as described below.Placement/Treatment MethodologyAll net acidity material is to be placed below MSL, with ≥ 3X ANC PASS material to be placed aboveMSL but monitored/tested to ensure neutralization and balance of material to be placed in specific areas42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document4-20

for higher level of testing and treatment as required. Treatment for the final material may includerelocation under water and/or neutralization with lime.4.2.3 Bund-wall LiningThe bund wall will be lined with geofabric to limit the transmission of fines through the wall. Where thereexists a potential need for further control on the egress of PASS material, non-PASS dredged spoil willbe placed against the bund to provide further barriers to migration.4.2.4 Placement ProgressionPlacement of material may commence at the south-east corner adjacent to the existing reclamation andcontinue north and west. Non PASS material will be placed in the shallower areas allowing for the netacidity/PASS material to be placed in the deeper areas underwater.Placement of non PASS material in the shallower areas will allow for the development of containmentareas to treat marginal material that has been identified as requiring neutralization.The discharge from the contained area will be diverted into a bunded area and any discharge into themain pond will tested and treated as required prior to release.Following treatment the material will be further protected through capping by semi impervious non PASSdredge material.4.2.5 Sampling and TestingSampling and testing will be carried out in accordance with Guidelines for Sampling and Analysis ofLowland Acid Sulfate Soils in Queensland 1998 (QASSIT, Queensland Acid Sulfate Soils InvestigationTeam) and the Queensland Acid Sulfate Soil Technical Manual Soil Management Guidelines (2002) forASS/PASS.4.2.6 CappingCapping with semi-impervious material and planting of the reclamation will occur progressively to providean additional level of mitigation through the reduction of leaching.4.3 Description of Harbour4.3.1 Submission #12Communicate more openly to the public to correct the misconception that Gladstone is a deep waterharbour.The Port of Gladstone is considered to be a deep water port in terms of its ability to handle Cape sizevessels without the requirement to carry out cost prohibitive dredging. Very few (if any) “deep water”ports in the world would require no capital or maintenance dredging.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document4-21

GPC recognises that some dredging both capital and maintenance is required within the Port. Dredgingof particular areas within the Port extends the naturally deep water sections to provide for additionalcapacity. Individual projects proceed only if they are financially viable, which includes costs associatedwith development and maintenance dredging.4.3.2 Submission #3Proposed design must allow for progressive capping and revegetation of the outer side walls of thereclamation mound as it is created. Otherwise reclamation would be a prominent scar on Gladstonelandscape for an unacceptable length of time. (Up to 24 years before mound is fully reclaimed andvegetated).GPC recognises the need to progressively revegetate the mound both in terms of visual impact anderosion control. Until the extent and timing of the dredging associated the LNG industry is confirmedGPC is unable to prepare a draft revegetation plan.4.4 Stormwater Management4.4.1 Stormwater DischargeSubmission #2 Amend reclamation construction plans to provide for discharge of all dredge spoil drain water andstormwater from any part of the reclamation area not fully stabilized, and with appropriate storm waterquality management systems, at a suitably designed discharge point at the northern end of theeastern wall of Fisherman’s Landing Northern Expansion.The reclamation design currently shows a stormwater management pond located at the northwest cornerof the reclamation, with the rationale and details of the concept provided in the EIS within Chapter 2 (pp2-43 to 2-47), and Chapter 8 (pp 8-9 to 8-11). Figure 2-23 indicates the stormwater managementnetwork, with several discharge points, each of which is linked to a treatment measure. The aim of theconcept is to treat all stormwater post construction, with stabilisation of the reclamation surface a keypriority.Coupled with GPC’s agreement to move the decant outfall to the NE corner during dredging, the systemwill provide flexibility over the life of the reclamation.The issue of decant outfall location is further discussed in Section 8.2.5.4.4.2 Erosion of Reclamation AreaSubmission #11 Describe mitigation for erosion of reclamation area while under construction and detail how quality ofstormwater leaving the site will have sediment reduced/removed.Refer to Section 2.4.3 of the WB EIS (Stormwater Drainage) and also Figure 2-23 of the aforementionedreport (attached again here as Figure 4-1).42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document4-22

Section 2.4.3 of the WB EIS states the following:"The conceptual design of the stormwater drainage system was based on industry norms and standards,with due consideration for possible future land use, staged construction, operation and maintenance, asfollows:The site will be free draining towards the outer perimeter, with slopes generally ranging between1:100 and 1:200. The mound has a general slope of 1:6.The outer perimeter is completely enclosed by channels, draining towards a series of stormwaterquality improvement devices.The channel configuration takes cognisance of possible future industrial development, to ensure that:– the stormwater drainage system is not adversely impacted during possible future development ofindustrial sites; and– the segregation of “clean” and “dirty” water is practicable.Contour drains on the mound are at 50 m centres (horizontally, to allow for drainage to be staged asconstruction of the mound proceeds.The majority of the proposed Reclamation Area, including the mound, discharges via a largestormwater quality improvement device into the intertidal zone / remnant bay area in the northwest.The remainder of the Reclamation Area discharges via a series of stormwater quality improvementdevices at numerous points along the outer perimeter (two in the southwest, discharging into theintertidal channel; two in the north, discharging into the intertidal zone / remnant bay area; and six inthe east, discharging into the open waters of Port Curtis).No discharge is proposed along the land attached southern end, to the existing Fisherman’s LandingNorthern Expansion."Section 2.4.3 of the WB EIS also states that:"Type D wet sediment basins usually consists of a settling pond, a decant system, and a high-flowemergency spillway and are designed to retain sediment-laden water for extended periods, allowingadequate time for the gravitational settlement of fine sediment particles. Operation of these basins maybe assisted through the use of chemical flocculants. Ideally, these basins are not drained until a suitablewater quality has been obtained within the basin."and“To limit soil erosion and loss at source, all exposed surfaces on the proposed Reclamation Area will beappropriately vegetated as soon as is practicable and structural source control systems, such assediment fences, will be employed to further limit soil erosion. “In summary of the above, it is proposed that the stormwater quality improvement devices (sedimentbasins) and perimeter channels be constructed to ensure that all stormwater run-off is intercepted,directed to the sediment basins and treated prior to release. As a further measure of control, it has beenrecommended that structural source control systems be employed as soon as practicable.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document4-23

4.4.3 Stormwater/GroundwaterStormwater from all reclaimed areas will be directed into the main settlement pond prior to discharge intothe harbour. Water will be tested and treated (as required) prior to discharge in accordance with theDMP.Groundwater bores will be installed at agreed locations and monitored as per the DMP.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document4-24

311,000311,500312,000312,500313,000313,5007,371,000Based on or contains data provided by the State of QLD. Inconsideration of the State permitting use of the data youacknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness,currency or suitability) and accepts no liability (including limitation,liability in negligence) for any loss, damage of costs (includingconsequential damage) relating to any use of the data. Data mustnot be used for direct marketing or be used in breach of the privacy laws.7,371,000Bund017,370,500Bund022347,370,5007,370,000Bund021b57,370,0001a7,369,500PrimarySedimentBasin1:2001:17567,369,5001:61:1007Bund037,369,0001:67,369,000Channel2Channel11:61:200Channel38Bund017,368,5001:61:1001:2007,368,000Channel497,368,50011Bund03107,368,000311,000311,500312,000312,500313,000313,500LEGENDBundCatchment BoundariesFuture Cadastre (indicative only)Sediment Basin (Primary)Sediment Basin (Secondary)Rock ChuteDrainage ChannelsFlow DirectionIndicative Grade1:15,000 (at A4)o0 100 200 300 400 500MetresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of Australia 1994Grid: Map Grid of Australia, Zone 56G:\42\15386\GIS\WesternBasinSupplementaryEIS\Mxd\4215386-56_434_rev_bPort of GladstoneWestern Basin Supplementary EISConcept Stormwater Design forFinal Reclamation SurfaceJob Number 42-15386Revision BDate 01 Sept 2009Figure 4-01Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.com© 2010. This document is and shall remain the property of GHD. The document may only be used for the purpose for which it was produced. Unauthorised use of this document in any way is prohibited.While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd and Data Custodians make no representations or warranties about its accuracy, completeness or suitability for any particular purpose. GHD Pty Ltd and Data Custodianscannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incompleteor unsuitable in any way and for any reason.Data source: Aerial Photo (flown 2007) - DERM; Storm water data - GHD.

5. Dredging Methodology5.1 Submission OverviewA number of submissions, particularly those from the Department o Environment and ResourceManagement (DERM), discuss the proposed dredging method, and raise queries as to the relativeimpacts of TSHD as opposed to CSD equipment, and the impacts associated with rehandling. Thischapter of the response deals with a review of the proposed dredging method for the Project, whilstChapter 18 addresses the potential decreases in turbidity, should offshore disposal become a viableoption, thereby removing most, if not all, rehandling.This chapter also provided a response to the issues of:The number of dredgers operating simultaneously;The potential for pumping from TSHD direct to the reclamation;Understanding how overflow dredging might operate.5.1.1 Submission #2 The submission suggests the proponent needs to justify the proposed methodology for dredging andtransfer of dredge spoil to the reclamation area in terms of minimising sediment suspension in PortCurtis waters while maintaining a viable project.It is suggested by the submitter that most of the suspended sediment is likely to result from overflowdredging, and that there are few if any methods to contain material dumped by a trailing suctionhopper dredge (TSHD). The submitter also notes that “Where two such units are operatingsimultaneously (Scenario 1 with Stages 1A and 1B), the sediment load at Fisherman’s Landing dueto dumping would be likely to be doubled. The EIS states that spoil will be pumped directly from aCSD, or bottom dumped in proximity to the reclamation area by a TSHD and then pumped via a CSDinto the reclamation area. However the latter method will significantly increase sediment loading withconsequent increased impacts on seagrass to the north and south of fisherman’s Landing. Nomodelling has been undertaken for the direct pumping method, although the reduction in turbiditylevels can be inferred from other scenarios not involving use of a TSHD. Although a TSHD operatingin overflow mode is the most efficient means of dredging Targinie Chanel, no justification has beenprovided for its use for the swing basin. Dredging of the northern expansion of the Fisherman’sLanding berths (Stage 3) and the channel to Laird Point (Stage 2) is proposed to use a CSD.Modelling of potential dredge plumes associated with Stage 1B did not address alternatives, such aspump-out from the TSHD rather than dumping, or the use of a CSD for the swing basin dredging.The reduced turbidity associated with these options can be partly deduced by reviewing Scenarios 2and 3 model outputs.”42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-26

The submission suggests the proponent should justify the use of trailing suction hopper dredge(TSHD) overflow dredging, with associated impacts on water quality, for berth and swing basindredging at Fisherman’s Landing rather than non-overflow dredging or cutter suction dredging.Additionally the submission suggests to justify bottom dumping the TSHD at Fisherman’s Landingwith associated impacts on water quality, rather than pumping the material directly to the reclamationarea.Table 1-2 Project Timing and Table 7-17 Overview of the Four Hydrodynamic Modelling Scenariosshows Stage 1A and 1B to be dredged concurrently over two years (2010-2012). This is inconsistentwith Table 2-9 Dredging Methodology Summary which appears to incorrectly show stage 1A and 1Bto be dredged consecutively over four years.Justify the use of TSHD overflow dredging, with associated impacts on water quality, for berth and swingbasin dredging at Fisherman’s Landing rather than non-overflow dredging or cutter suction dredging.Justify bottom dumping by TSHD at Fisherman’s Landing, with associated impacts on water quality,rather than pumping the material directly onto the reclamation area.Justify the proposed bottom discharge from the TSHDs and secondary dredging to place in thereclamation area, with associated significantly increased sediment loading to water and consequentincreased impacts on seagrass to the north and south of Fisherman’s Landing against the practicalityand cost of pumping spoil directly onto the reclamation area.Clearly state the options available to minimise sediment loading to port Curtis waters, and justify useof methodology that is not best practice in achieving this. Options that should be considered include:– Minimising use of TSHD, especially near Fisherman’s Landing;– Restricting use of overflow dredging by TSHD, especially near Fisherman’s Landing;– Avoiding or reducing rehandling of dredge spoil in transfer to the reclamation area;– Reducing the number of TSHD operations at any one time;– (balance of DERM suggestions from this list are dealt with in Chapter 8 and 9).5.1.2 Submission #4 Additional information is required on dredge disposal during flood tides, and use of overflow dredging.5.1.3 Submission #12 GPC’s intention to double-pump dredge material when discharging from the TSHD’s is a concern.Pump discharge straight into reclamation area and reduce risk – use a single handling optionwhenever possible.Use a non-overflow dredge mode.5.2 BackgroundAt the time of writing, the adopted dredging scenario comprised 4 stages, with descriptions provided inChapter 2 of the WB EIS. Stage 1 was split into 2 sub-stages (1A and 1B). Table 2-1 indicated the42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-27

volumes associated with each stage, which totalled some 36 million m 3 of material to be dredged.Volume 6 of the WB EIS then included additional dredging for the APLNG project of 12 million m 3 .Indicative timings were provided, with dredging commencing as early as late 2010.The primary means of dredging were to comprise:Use of cutter suction dredgers (CSD) in shallower areas, and at locations where the material requireda CSD.Trailing suction hopper dredgers operating in overflow mode, with dumping in the vicinity ofFisherman’s Landing, and rehandling via CSD pumping to the reclamation.Table 2-9 of the WB EIS suggested that two TSHDs could be operating simultaneously, one for up to8.8 months, and a second for 9.5 months. It should be noted that contrary to the comments above,plume modelling did assume up to four dredgers operating simultaneously. It had been assumedthat this would involve one TSHD and three CSD, along with the associated rate of decant. Thisparallel dredging does allow for stages 1A and 1B to be occurring simultaneously. However, from aefficiency perspective, it is noted that it is unlikely that two TSHD would be operating simultaneously.5.3 Response to SubmissionsWith the benefit of additional time, and some feedback from the dredging industry, a refinement to theproposed dredging methodology has been possible. Two updates are offered:A review of dredge volumesA review of dredge method.5.4 Dredging MethodologyThe following section provides an update of dredge methodology that is considered feasible. However,until a dredging contractor is selected, this information can only be regarded as indicative.5.4.1 StagesThis updated dredging methodology relates to the following proposed stages: Clinton Bypass, part ofTarginie Channel, Curtis Channel with marine offloading facility (MOF) access channels, individualMOF’s, and swing basins including berth pockets. The location of zones is provided inFigure 5-1.5.4.2 Clinton Bypass and Targinie Channel, Zones 1 and 2For these two zones, the following volumes and method are noted:Volume of approximately 1.4 million m 3 , 60% sand and gravel, 38% hard clay, 2% weathered rock.Preference for offshore disposal using TSHD, although the sand and gravel would be valuable inreclamation:42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-28

5.4.3 Curtis Channel, MOF’s, Swing Basins, Berth Pockets, Zones 3, 4, 5, 6, 7, 8, 9The total volume is approximately 12 million m 3 , with some sand and gravels, but 60% clays, silty claysand silts. Metod comments include:1.5 million m 3 in the lower section of Curtis Channel (section with depths over -8.0 m LAT) could bedredged by TSHD (15,000 m 3 cap) and dumped offshore. Onshore pumping (i.e. into reclaim) isunlikely with TSHD, due to clay content.Also within reach of large CSD with booster.Remainder of volume to be dredged using CSD with disposal to Western Basin Reclamation Area.Dredge access channel to MOF and actual MOF first. Use medium CSD and place under water inWB reclaim. Volume is approximately 1.5 million m 3 .5.4.4 Targinie Channel Widening and FL Swing Basin Deepening Zone 11Dredging details for Zone 11 are suggested as follows:Volume of about 1.6 million m 3 , mainly silty, sandy clays stiff to very stiff with sand/gravel pockets.Swing basin (volume of 1.25 million m 3 ) has substantial volume of PASS.– Dredge and pump ashore with medium CSD. .Widening channel, approximately 350,000 m 3 .– Dredge with CSD and booster and pump ashore in WB Reclamation Area.– Alternative is to use TSHD and dump in offshore disposal site.5.4.5 Curtis Channel Extension, Zone 10.For Zone 10:Volume of about 8.0 million m3, with substantial volume of fine material. First dredge MOF channel plus MOF with approx. volume of 2.3 million m 3 .Balance of materials from shipping channel and swing basin.– Pump with medium CSD to WB Reclamation Area.5.4.6 SummaryOption 1, all materials in onshore WB Reclamation Area.Option 2, WB Reclamation area disposal plus part offshore.– 650,000 m 3 (include overdredging) from Bypass / Targinie Channel, Zones 1 and 2.– 1,600,000 m 3 from Curtis Channel (Zone 3 and 5).– 1,200,000 m 3 from FL swing basin (contains PASS), Zone 11.– 400,000 m 3 from Targinie Widening, Zone 11.– 2,500,000 m 3 from MOF Curtis Channel Extension, Zone 10.6 - 8 million m 3 potential offshore disposal inclusive of overdredge.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-29

7,376,0007,375,000313,000314,000315,000316,000317,000318,000319,000320,000321,000322,000323,000324,000325,000Based on or contains data provided by the State of Queensland(Department of Natural Resources and Water) 2010. Inconsideration of the State permitting use of this data youacknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness,currency or suitability) and accepts no liability (including withoutlimitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data.Data must not be used for direct marketing or be used in breach ofthe privacy laws.7,376,0007,375,0007,372,0007,372,0007,371,000Fisherman's LandingHamilton PointTide IslandWiggins IslandsPicnic IslandDiamantina IslandGladstone Marina7,361,0007,361,0007,362,0007,362,0007,363,0007,363,0007,364,0007,364,0007,373,0007,373,0007,374,0007,374,00014APLNGMOF7,370,000121310/21010a/b9/2QGCMOFQGCCONDOC7,371,0007,370,0007,369,00011/299877,369,0007,368,0001165 6434GLNGMOF7,368,0007,367,000157,367,0007,366,0007,365,000Wiggins IslandCoal Terninal(Approved)217,366,0007,365,000313,000314,000315,000316,000317,000318,000319,000320,000321,000322,000323,000324,000325,0001:70,000 (at A4)o0 500 1,000 1,500 2,000MetresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of Australia 1994Grid: Map Grid of Australia, Zone 56G:\42\15386\GIS\WesternBasinSupplementaryEIS\MXDs\4215386-56_447.mxdJob Number 42-15386Port of GladstoneRevision AWestern Basin Supplementary EISDate 14 April 2010Dredge ZonesFigure 5 - 1Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.com© 2010. This document is and shall remain the property of GHD. The document may only be used for the purpose for which it was produced. Unauthorised use of this document in any way is prohibited.While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd and Data Custodians make no representations or warranties about its accuracy, completeness or suitability for any particular purpose. GHD Pty Ltd and Data Custodianscannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incompleteor unsuitable in any way and for any reason.Data Source: Aerial Photo (flown 2007) - © State of Queensland (Department of Environment and Resource Management), 2010. Dredge Area - Gladstone Ports Corporation, March 2010.

5.5 Dredge Volumes5.5.1 Overview of Dredge StagesTable 5-1 summarises the maximum proposed volumes for dredging stages for the Western BasinDredging and Disposal Project (should each project proceed). These are shown on Figure 5-2. EachDredging Stage is required to either support various LNG proponents (Stages 1A & 1B) or future importor export facilities for as yet unidentified proponents and/or GPC (Stages 2, 3 and 4). The current EISaddresses all dredging stages and overall footprint of development to provide a cumulative assessmentof potential impacts.Table 5-1Dredging stages for the Western Basin Dredging and Disposal ProjectDredging Stage Description VolumeStage 1AStage 1BStage 2Stage 3Stage 4Curtis Channel & MOF(s) - LNG PrecinctFisherman’s Landing LNGLaird PointFisherman’s Landing DevelopmentLNG final stages & Hamilton Point24.2 million m 35.6 million m 3*4.5 million m 35.5 million m 35.5 million m 3*Part of this dredging may be undertaken by the proponent under a separate approvals processTotal45.3 million m 35.5.2 Project TimingThe construction of the bund wall for the Western Basin Reclamation Area is anticipated to commenceimmediately upon receipt of Project approvals in mid 2010. The construction of the bund wall is likely tobe completed within 12 to 18 months of commencement.The capital dredging of the Western Basin will occur in stages and the rate of development will becontrolled by the demands of industry locating in the Gladstone region requiring access to port facilities.Operational works approvals will be sought for each Project stage as they are required. Table 5-2provides an overview of the current likely timing of the stages of the Project.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-31

7,376,0007,375,000313,000314,000315,000316,000317,000318,000319,000320,000321,000322,000323,000324,000325,000Based on or contains data provided by the State of Queensland(Department of Natural Resources and Water) 2010. Inconsideration of the State permitting use of this data youacknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness,currency or suitability) and accepts no liability (including withoutlimitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data.Data must not be used for direct marketing or be used in breach ofthe privacy laws.7,376,0007,375,0007,372,0007,372,0007,371,0007,371,0007,370,0007,369,0007,370,000Fisherman's LandingHamilton PointTide IslandWiggins IslandsPicnic IslandDiamantina IslandGladstone Marina7,361,0007,361,0007,362,0007,362,0007,363,0007,363,0007,364,0007,364,0007,373,0007,373,0007,374,0007,374,000APLNGMOFQGCMOFQGCCONDOC7,369,0007,368,000GLNGMOF7,368,0007,367,0007,367,0007,366,0007,365,000Wiggins IslandCoal Terninal(Approved)7,366,0007,365,000313,000314,000315,000316,000317,000318,000319,000320,000321,000322,000323,000324,000325,000Fisherman's Landing Northern ExpansionWestern Basin Reclamation AreaWiggins Island Coal Terminal (Approved)Existing Channels, Swing Basins and BerthsProposed Dredge StagesStage 1A - North China Bay LNG PrecinctStage 1B - Fisherman's Landing LNGStage 2 - Laird Point LNGStage 3 - Fisherman's LandingStage 4 - Hamilton Point1:70,000 (at A4)o0 500 1,000 1,500 2,000MetresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of Australia 1994Grid: Map Grid of Australia, Zone 56G:\42\15386\GIS\WesternBasinSupplementaryEIS\MXDs\4215386-56_448.mxdPort of GladstoneWestern Basin Supplementary EISWestern Basin Dredging and DisposalProject Location and Project ComponentsJob Number 42-15386Revision ADate 14 April 2010Figure 5 - 2Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.com© 2010. This document is and shall remain the property of GHD. The document may only be used for the purpose for which it was produced. Unauthorised use of this document in any way is prohibited.While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd and Data Custodians make no representations or warranties about its accuracy, completeness or suitability for any particular purpose. GHD Pty Ltd and Data Custodianscannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incompleteor unsuitable in any way and for any reason.Data Source: Aerial Photo (flown 2007) - © State of Queensland (Department of Environment and Resource Management), 2010. Dredge Area - Gladstone Ports Corporation, March 2010.

Table 5-2Project timingProject Stage*Stage 1A – Curtis Channel - LNG IndustryPrecinctStage 1B – Fisherman’s Landing LNGInitial -10.6m & 180m wideChannelUltimate -13.0m & 200m wide ChannelStage 2 – Laird PointStage 3 – Fisherman’s Landing DevelopmentStage 4 – LNG final stages & Hamilton PointPotential Length and Timing of DredgingQ2 2011 – Q2 2014 ( 3 years)Q3 2011 – Q1 2012 (7 months)(dredged concurrently with Stage 1A)Q3 2014 – Q2 2015 (1 year)Q3 2014 (follows after Stage 1A and Initial 1B)To be determined (will be staged over a number ofyears)To be determined (will be staged over a number ofyears)5.5.3 Details of Dredging StagesTable 5-3 presents the likely staging and timing for the proposed dredging outlined in the previoussection.Table 5-3Indicative timing for each dredging scenario and stageScenario Stage Dredge Area Start Date Completion Date1 Stage 1A QGC & Santos Marine OffloadFacility (MOF) & Berth PocketsQ2 2011 Q3 2011APLNG MOFs Q2 2011 Q2 2012Curtis Channel & Clinton By-Pass Q3 2011 Q3 2014Curtis Channel Swing Basins2 Stage 1BTarginie ChannelInitial-10.6m & 180m wide channelQ3 2011Q1 2012Ultimate13.0m & 200m wide channel & swingbasinQ3 2014Q2 2015-Stage 2Laird Point ChannelLaird Point Swing Basin3 Stage 3 Fisherman’s Landing Will be dredged in stages as required by futureproponentsStage 4 LNG final stages & Hamilton Point Will be dredged in stages as required by futureproponents42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-33

5.5.4 Reclamation StagingThe Western Basin Reclamation Area bund wall will be fully constructed prior to the commencement ofdredging. Should the Fisherman’s Landing Northern Expansion reclamation be approved (under aseparate EIS process that is currently being undertaken) construction of a portion of that reclamationmay be undertaken prior to the approval and commencement of the Western Basin Reclamation Area.The Fisherman’s Landing Northern Expansion reclamation will therefore have the potential to containearly works material from one or more of the LNG facilities proposed for Curtis Island. The WesternBasin Reclamation would then incorporate this initial portion of the Fisherman’s Landing NorthernExpansion.To enable the construction of the complete bund wall in one year, it is proposed to construct the WesternBasin Reclamation Area bund walls from three ‘fronts’. Two of these fronts start from the existingFisherman’s Landing reclamation, and a third starts from part way along the western bund wall). Thethird ‘front’ will be from the end of the off-road haul route to a portion of the western bund wall, with an atgradecrossing of what will be the intertidal channel constructed to enable this access. The at-gradecrossing will need to be designed to minimise disruption to water flows during tidal movements and willbe removed upon completion of the bund wall construction. Separate approval will be soughtfor theconstruction of the crossing in conjunction with the haul road.5.5.5 Proposed Dredging MethodsIn accordance with Section 2.3 of the ToR, this section describes the methods proposed for the dredgingof the new berth pockets, swing basins and channels. This information is drawn from a report entitled theDredging Works Description for the Western Basin Dredging and Disposal Project (GHD 2009b).Definition of Terms and Dredging Sub-AreasFor the purposes of specifying the appropriate dredging equipment for the proposed works, the dredgingstages were divided into the following sub-areas:Clinton Bypass Wedge (Stage 1A).Clinton Bypass Channel (Stage 1A).Curtis Channel – North (Stage 1A).Curtis Channel – Middle (Stage 1A).Curtis Channel – South (Stage 1A).Targinie Channel (Stage 1B).Fisherman’s Landing Swing Basin (Stage 1B Initial and Stage 1B Ultimate). Laird Point (Stage 2). Fisherman’s Landing (Stage 3). LNG final stages and Hamilton Point (Stage 4).42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-34

5.5.6 Design of Dredged AreasDesign parameters are provided in Table 5-4 with key considerations as follows:An LNG industry requirement is for their shipping not to be limited to departing only on certain stagesof the tide, therefore the swing basin and berth pocket are the same depth. Stages 3 and 4 however,are likely to cater for various product types and ship sizes and may have berth pockets deeper thanthe swing basins;Table 5-4 shows design depths. These are the depths that will be officially declared by the HarbourMaster for the channels and swing basins. The volume calculations include an allowance for 0.3 m ofover-dredging (caters for dredging tolerance and over-dredging to allow for siltation). Therefore, anapproved depth of maximum -13.30 m LAT (lowest astronomical tide) would be applied; andThe datum is LAT. Therefore, the numbers represent the depth of water available in each area at thelowest astronomical tide.Dredging MethodologyTable 5-5 presents a feasible dredging methodology for each of the scenarios. The size and combinationof plant options likely to be suitable to undertake the works have been assessed on the basis of the timeconstraints associated with completion of each portion of the works for the Project and the informationthat is currently available regarding the material to be dredged. The likely primary dredge and auxiliaryplant to be used are presented.The global dredging fleet is limited and access to specific size plants at the required project time can notbe guaranteed. All proposed works will undergo a tendering process. The available equipment to executethe works will depend on the market at the time of tendering and any performance requirementsspecified in the Project approvals.Production rates for each dredger type take into account the type and size of the dredger, foreseendelays (including ship movements), the location of the dredge area, the size and shape of the dredgearea, distance to the material relocation area, disposal method, dredging depth and type of materialbeing dredged. It is for this reason that the same type and size dredger may have different productionrates for differing areas.The dredging methodology proposed:Confirms that plant is available on the world market to complete the work to the timelines required forthe various projects; andProvides the basis upon which the environmental impacts were assessed for a range of dredgingplant.Dredging of a “Material Discharge Area” will be required north of the existing Fisherman’s Landing SwingBasin prior to the commencement of the proposed capital dredging if a TSHD is employed. The TSHDwill employ either of the following disposal options:Bottom dump the material for rehandling, using a CSD to pump the material into the ReclamationArea; orPump the material from the hopper directly into the Reclamation Area.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-35

An area with sufficient depth close to the Reclamation Area will be required if the bottom dumpmethodology is employed. If the pump out option is adopted, then the TSHD will require an area clear ofshipping movements where it can pump-out the material, which typically takes 1-2 hours. In either case,a suitable Material Discharge Area will need to be developed. Should the “sea disposal” option beapproved, the requirement for a “Material Discharge Area” may be eliminated.The proposed timing for the dredging of each stage and the anticipated length of the dredging campaignare summarised in Table 5-5. The dredgers are likely to operate on 12 hour shifts and change over at 6am and 6 pm. At the peak of the dredging operation (Scenario 1), there are likely to be four dredgers inplace (two cutter and two trailer dredgers).Marine Offload Facilities DesignThe QGC, APLNG and GLNG projects on Curtis Island are proposing to construct Marine OffloadFacilities (MOFs) to provide facilities for the transport of construction materials, equipment and personnelto Curtis Island, as there is no existing road, rail or shipping access to these areas.A description of these facilities is based on information provided by the proponents. The marine flora andfauna and sediment characteristics of the dredging footprint for both MOFs have been assessed as partof the overall marine ecological and sediment quality assessments documented in Chapter 10 andChapter 9 respectively. Water quality impacts during dredging are also discussed in Chapter 7.QGC MOFThe QGC MOF requires initial deepening of the access channel to a depth of -7.8 m LAT to approach theMOF and involves removing 2,000,000 m 3 of material.A backhoe dredge may be utilised in some of the shallow areas of the MOF, and a CSD would be usedfor the remaining area and access channel.GLNG MOFThe GLNG MOF design is not finalised, however it will have a maximum dredge volume of 30,000 m 3 .The MOF is likely to consist of a breakwater structure and a dredged area to allow barges and ferries toberth and offload. The dredging method cannot be finalised until the design is finalised. The MOF will bedredged by the same dredging plant utilised for Stage 1A.APLNG MOFDetails of APLNG’s MOF are not available at the time of writing, and hence the dredging method is to beconfirmed.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-36

Table 5-4Design of dredged areas for each dredging stageScenario Stage Dredge Area Design Depth NominalOverdredgeChannelToeline WidthBatterSlope V:HVolumemillionm 3#1 Stage 1A QGC MOF + Approach Channel -7.8 m LAT -7.8 m LAT 1:3 2GLNG MOF/APLNG MOF TBC** TBC 1:3 0.03Curtis Channel & Clinton By-Pass-13 m LAT -13.3 m LAT 200 m 1:324.0Curtis Channel Swing Basin -13 m LAT -13.3 m LAT 600 m1:32 Stage 1B Targinie Channel -13 m LAT -13.3 m LAT 200 m 1:34.8Fisherman’s Landing SwingBasin-13 m LAT -13.3 m LAT 650 m1:3Stage 2 Laird Point Channel -13 m LAT -13.3 m LAT 200 m 1:34.5Laird Point Swing Basin -13 m LAT -13.3 m LAT 650 m1:33 Stage 3* Fisherman’s Landing -13 m LAT -13.3 m LAT 450 m 1:3 5.5Stage 4* LNG final stages/Hamilton Point -13.0 / -16.0 mLATVaried 1:3 4.7#Volume calculations are based on approved depths.* Stages 3 and 4 will be dredged as and when new berths are required.** To be confirmed with final design.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-37

Table 5-5Dredging methodology summaryScenarioScenarioStartDateScenarioCompletionDateLikely DredgerOptionDredge AreaAuxiliaryDredgerOptionDredgeVolume(Million m 3 )EstimatedCompletionTime(months)1 Q2 2011 Q2 2014Large TSHD/CSDTotal Dredging Time - 6months to 10monthsClinton Bypass Wedge (Stage1A)Clinton Bypass Channel (Stage1A)Backhoe 0.05 0.1 - 0.2Med TSHD 2.1– 2.5 – 4.5Curtis Channel – Part Middle &South (Stage 1A)Med CSD/TSHD2.63.5 – 5.5Large CSD & Med CSDTotal dredging time26monthsCurtis Channel – North (Stage1A)Curtis Channel – Middle (Stage1A)Backhoe / MedCSDMed CSD8.6 1111.715Large TSHDTotal Dredging Time 2 –4 monthsTarginie Channel – (Initial Stage1B)-10.6 & 180m channelMed TSHD1.12.0 - 42 Q3 2014 Q2 2015 Large TSHDTotal Dredging Time4.5 months to 7 monthsFisherman’s Landing SwingBasin –(Ultimate Stage 1B)-13.0m & 200m channel + swingbasinMed TSHD 3.3 4.5 - 742/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-38

ScenarioScenarioStartDateScenarioCompletionDateLikely DredgerOptionDredge AreaAuxiliaryDredgerOptionDredgeVolume(Million m 3 )EstimatedCompletionTime(months)Large CSD orLargeTSHDLaird Point (Stage 2) Nil 4.7 6 - 9Total Dredging Time 6months to 9 months3* FuturePlannedDredgingFuturePlannedDredgingLarge CSDTotal Dredging Time13.1 monthsFisherman’s Landing (Stage 3) Nil 5.7 7.6LNG final stages & HamiltonPoint (Stage 4)Nil 4.9 6.2* Subject to the demand for this scenario to be completed, a medium sized CSD may also be capable of completing this work.42/15386/400126Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document5-39

6. Hydrodynamic ModellingComments made with respect to the hydrodynamic modelling conducted for the Project have focusedprimarily on wave modelling, and were provided by an external reviewer acting for Submitter #4.Responses are provided in this Chapter.6.1 Hydrodynamic Model6.1.1 Model MeshGiven that the hydrodynamic model mesh covers a large area, an additional (finer) mesh at the keylocations of interest (in the Western Basin of Port Curtis) would be advantageous in obtaining a moreaccurate resolution of key hydrodynamic components in the study area.The hydrodynamic model mesh was illustrated in Figures 2-1 and 2-2 of the WB EIS, with discussion inSection 2-2 of the Numerical Modelling Studies report (Appendix J of the WB EIS). Further detaileddiscussion of the mesh development was provided in Section 2-4 of the Calibration and Validation report(Appendix J of the WB EIS). The model is built on a flexible mesh with particular focus and enhancedresolution in the Western Basin study area to ensure appropriate representation of bathymetric andconstructed features that influence flow conditions. This includes existing and proposed dredgedchannels, swing basins and berth pockets as well as Reclamation Areas. Model calibration demonstratesgood representation of hydrodynamic conditions illustrating the adequacy of the mesh used. Furtherrefinement of the mesh is unlikely to provide any significant benefits or change the findings.6.1.2 Model DurationSince the tidal range within Port Curtis is relatively large (varies between 4.7 m and 6 m dependingon location), the hydrodynamic modelling could have been improved with simulation of severalscenarios of water levels that could occur during the dredging period (for each bathymetry scenario).Hydrodynamic modelling was undertaken for a 2 month period covering large variations in ranges.Details including how this period compares to annual variations were provided in Section 2.2 of theNumerical Modelling Studies report (Appendix J of the WB EIS).6.2 Wave Model6.2.1 Wave Model MeshA more detailed wave model mesh (say 20 m x 20 m rather than 50 m x 50 m used) would providemore reliable computed results. Alternatively, given the complex terrain of the study area, anunstructured grid, or (if applicable) a similar model mesh used in the TUFLOW model, could beapplied for the SWAN wave modelling.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document6-40

The sizes of the main controlling features in the study area are such that they are adequatelyrepresented by a 50 m x 50 m wave model mesh. A more detailed wave model mesh in the study area isunlikely to provide any significant benefits or change the findings.6.2.2 Wave PropagationThe phase-decoupled method employed in SWAN does not rigorously handle wavediffraction/refraction in the harbour basin or in front of reflecting obstacles. These obstacles includenumerous islands in the basin and existing port structures.The wave modelling required the ability to include local wave generation as well as propagation. SWANhas this ability, and includes wave refraction as well as a representation of wave diffraction. While thereare some limitations with respect to diffraction and reflection, this is common to all spectral wavemodelling packages. Numerical wave models better suited to simulating wave diffraction processesgenerally do not have any capabilities to simulate the generation of wave energy from local winds andare therefore not suitable for the overall study area. It is considered that SWAN provides an adequaterepresentation of the wave processes for the purposes of the study.6.2.3 Wave Induced CurrentsThere was general limited information provided on wave-induced currents and the physicalprocesses that generate them, and no calibration or validation of these processes against field data.Wave-induced currents and wave impacts are particularly important to take into account in the caseof a storm surge approaching the region during a high spring tide period.The macro tidal range of Port Curtis is such that currents are dominated by tidal influences (refer toSection 2.1 of the Numerical Modelling Studies report, Appendix J of the WB EIS). Wave inducedcurrents only occur where waves break and develop along continuous shorelines. The sheltered natureof Port Curtis is such that day to day wave conditions are mild to moderate (refer to Section 5.3.2 of theNumerical Modelling Studies report, Appendix J of the WB EIS). Extreme waves are also limited in height(refer Section 5.3.1 of the Numerical Modelling Studies report, Appendix J of the WB EIS) and occurinfrequently for short periods. As such, there is negligible longshore transport along the shorelines in thestudy area. It is therefore considered that wave induced currents are not a significant influence on thehydrodynamic and morphologic processes and it is adequate to have not included detailed assessmentof them.From a storm tide perspective, strong currents will tend to be of most concern where existing low lyingland is at risk.The SWAN wave model does not calculate wave-induced currents. As stated in the model manual(SWAN User Manual version 40.72ABCD, 2009), such currents should be provided as input toSWAN, for example from a circulation model which can be driven by waves from SWAN in aniterative procedure. As noted above, wave-induced currents could be a matter of concern duringextreme conditions.As above, wave induced currents are not considered to have a significant influence and inclusion of themin the SWAN modelling would have limited effect on the calculated wave conditions.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document6-41

Wave-induced (bottom) orbital velocities play a key role for sediment plume modelling. This bottomorbital velocity is a function of the wave height, wave period and the water depth. Given thecomplicated bathymetry/geometry of the harbour basin, a more advanced wave model could beconsidered (rather than SWAN) for modelling of the nearshore and inner harbour areas. Withoutinclusion of this process the extent of plumes could be underestimated, for example.Tidal currents are the dominant natural sediment re-suspension mechanism with an observed springneapand semi-diurnal signal in measured data (refer to Section 4.1 and Figure 4-1 of the NumericalModelling Studies report, Appendix J of the WB EIS). Any direct correlation with wave-height (or period)is less clearly discerned. The plume assessments carried out are considered adequate. Plume sedimentsettling parameters have been calibrated using measured data and include provision for settlingattenuation as a function of bed shear stress (refer to Section 4.2.5 and Figure 4-3 of the NumericalModelling Studies report, Appendix J of the WB EIS). Further plume monitoring and modeldescriptions/validation were provided in Chapter 5 of the Calibration and Validation report (Appendix J ofthe WB EIS). Wave heights and periods are generally low and hence (bottom) orbital velocities will havelittle influence in the deep channel areas. The far field advection and extents of the dredge plumesthrough the main channel areas, are therefore unlikely to be underestimated by not including waveinfluences. There is limited potential for the extent of dredge plumes to be underestimated in the shallowzones.6.2.4 Extreme WavesIn the extreme wave condition impact assessment, only two water levels of 3.3 m and 3.5 mAHDwere considered. It could be argued that higher water levels would be associated with say 50 yearARI and 100 year ARI wave conditions and should be considered for wave modelling.Extreme wave modelling was undertaken for design conditions (refer to Section 5.3.1 of the NumericalModelling Studies report, Appendix J of the WB EIS). It is understood that the adopted water levels arerepresentative of 50 year and 100 year ARI storm tide conditions.6.2.5 Impacts of Wave Induced CurrentsGiven the limitations of the SWAN wave modelling and other limitations as noted above, it is possiblethat impacts of changing wave and current patterns have been understated, and secondary impactssuch as effects on bank erosion and stability of batter slopes have not been fully considered.As outlined above, the macro tidal range of Port Curtis dominates the hydrodynamic processes andthese have been adequately assessed. The influences of waves on these processes are considered tobe limited. The secondary impacts on the stability of batter slopes were beyond the scope of themodelling studies, being of greater relevance to engineering design.6.2.6 Wave Height PlotsIn computed wave height plots (e.g. Figure 7-26), it would be clearer to display wave height contoursto enable assessment and determination of wave height at any specific location.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document6-42

The wave height plots shown in Appendix G of the Numerical Modelling Studies report (Appendix J of theWB EIS) originally had graduated colour shading of wave height. These SWAN wave model results havenow been replotted to show delineated colour contour shading (see Appendix B of this report).6.3 Combined Storm Surge, Tide and Wave Set-Up ModellingSubmission #12 calls for combined modelling of storm surge, tide and wave set-up. The detailedmodelling of storm surge is inherently very complicated, and is usually applied when existing low lyingareas are at risk, or planning for future development is required. It is not considered that the combinationof all facets will provide any meaningful change to the assessment of the proposed dredging project.6.4 Sediment TransportEvidence of verification/validation of the sediment transport module that was used, and discussion onits suitability and limitations would be beneficial.The sediment transport modelling approaches used in the impact assessment were detailed in Section 6of the Numerical Modelling Studies report (Appendix J of the WB EIS). Direct validation of predictedsediment transport rates is not usually possible due to the difficulty of obtaining measurements.However, the predicted base-case rates of sand-sized sediment transport (Table 6-2 of the NumericalModelling Studies report, Appendix J of the WB EIS) and fine sediment siltation (Table 6-3 of theNumerical Modelling Studies report, Appendix J of the WB EIS) are considered to be in adequateagreement with historical maintenance dredging volumes (Table 6-1 of the Numerical Modelling Studiesreport, Appendix J of the WB EIS) as described in the Numerical Modelling Studies report.There is a typographic error in Figures 7-28, 7-39 and 7-40 where the units of the Sand TransportPotential (header in the legend) should read as “m^3/yr” instead of “m^2/yr”.The sand transport density in the contour plots (Figure 6-8 to 6-14 of the Numerical Modelling Studiesreport, Appendix J of the WB EIS) have units of m 3 /annum/m (equivalent to m 2 /annum) and are correct.This is explained in the text of Section 6.5.1 of the Numerical Modelling Studies report (Appendix J of theEIS).6.5 Discussion of ResultsThere was only limited discussion on the simulated results for each scenario.Discussions of key results for each scenario are provided in following sections in the technical report(Appendix J of the WB EIS):– Tidal Hydraulics Section 2.4– Tidal Flushing Characteristics Section 3.4– Dredge Plume Dispersion Section 4.4– Wave Climate Section 5.3.2– Sediment Transport and Deposition Section 6.542/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document6-43

6.6 Report StructureThe structure of the reporting was complicated and could be improved. For example, a tablecontaining input and output data for each scenario could be provided in order to compare, analyseand study the results of each case.This appears to be a reference to a draft version of the main EIS document, which was modified prior tofinal release. This comment is therefore no longer applicable.6.7 Model Review6.7.1 Submission # 18Fisheries Queensland would request that the dredge plume model be reviewed by an independentexpert. The model is a critical component in determining the scale of impacts to marineplants/seagrass/fisheries habitat as well as developing an effective strategy to mitigate impacts.Consideration should b given to the possible improvement of the model by using a 3 dimensionalrather than 2 dimensional model. The robustness of the assumptions of turbidity created by thevarious combination of dredge types and methodology should be tested by a specialist in the field,and a report finding made available.The modelling work has been reviewed by an independent group, as indicated by the submissions andresponses provided above. Furthermore, a critical review was undertaken throughout the modellingstages from inception to final model runs.In relation to the second query, it is noted that Port Curtis waters do not vertically stratify hence the needfor a 3D model is not required.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document6-44

7. Mud Wave, Scour and Resuspension7.1 OverviewChapter 7 addresses the potential for turbidity arising from the possible formation of a mud wave, erosionof the seabed from high velocities, and the potential resuspension of material deposited during thedredging campaign.7.2 Mud Wave7.2.1 Submission #2As large quantities of unconsolidated fine sediments from dredge plumes would be more readilysuspended than naturally, partly stabilised bed material, the EIS should have discussed the likelyextent of mud displacement based on sediment characteristics and depth of soft sediments derivedfrom borehole data. Such assessment also should have addressed the practicality of preventing a‘mud wave’, particularly in locations where such displaced mud is likely to be relocated by currents,e.g. west of the western wall and around the NE corner. The effect of various shapes/profiles of theNE corner of the reclamation area on tidal current velocity, and associated scouring of bottomsubstrate should be presented together with clear justification for a particular design.The statement that disturbance of soft sediments by bund wall construction will be limited to the firstlayer of rocks is misleading. The bund wall will displace the soft mud and the resultant ‘mud wave’will have varying impacts on water quality and benthic communities depending on the depth of softmud, and therefore, volume displaced. This is particularly problematic in areas of high currentvelocity in the north and west. Nor is it clear that there is any way to mitigate such impacts, e.g. anyattempt to remove it in proximity to sensitive communities, particularly seagrass. Moreover, itsimpacts are likely to continue well beyond the construction stage.Construction of a reclamation bund within the Western Basin may result in the displacement of a layer ofsoft mud under the bund walls as a result of the weight of bund construction materials. The likelihood of amud wave forming, and the size that the mud wave might reach are uncertain. Hence, consideration hasbeen given to how a mud wave might be managed and whether it could erode.A manual assessment has been undertaken in order to consider the potential for erosion of the mudwave/mound, and is presented below.The mud wave is assumed to be of a pyramidal shape with dimensions of approximately 2 m height and10 m width along the entire perimeter of the proposed reclamation bund. Assuming a mud wave formsalong the entire length of the bund wall, it would have a total length approximately 5000 m, but due to thedifferential in sediment erosion potential (i.e. bed shear stress) at locations along the bund, mounderosion is analysed in segments.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-45

The erosion of a mud wave formed along the northern and western walls has not been considered in thisanalysis owing to the lack of bed shear stresses – model output suggests these are typically not strongenough to cause erosion. Bed shear stresses are typically less than 0.3 N/m 2 for the northern regionsand are expected to be lower for the western wall.The eastern wall has been divided into several segments based on hydrodynamic model output datapoints. Segments 1 to 5 (EW1 – EW5) along the eastern wall are of equal length of 500 m. Segment 5(EW5) was divided into a length of 300 m for Site 5 and 100 m lengths for Sites 6 and 7.Figure 7-1 Eastern mud wave/mound divided into segments for erosion analysis42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-46

Estimates of bed shear stress data at seven sites along the eastern wall (as obtained from hydrodynamicmodelling results) were used to ascertain the erosion potential for displaced mud mound throughcomparisons with the critical bed shear stress for erosion. The critical bed shear stress for erosion ofmud can be estimated as: critical1.20.0012dwhere ρ d is the dry density of mud. Due to the lack of site specific data, a value for the dry density 1 ofmud of 300 kg/m 3 has been adopted as suggested in literature (Mitchener and Torfs, 1996 and Flemmingand Delafontaine, 2000). The latter paper suggests that if the sediment is mostly mud (as compared to amixture of mud and sand), the dry density usually varies between 200 and 400 kg/m 3 . Figure 7-2 showsthat for typical variations in dry mud densities (i.e. 200 – 400 kg/m 3 ), the critical bed shear stress forerosion ranges between 0.69 and 1.59 N/m 2 .1.61.5Critical Shear Stress (N/m2)1.41.31.21.110.90.80.70.6200 250 300 350 400Dry Mud Density (kg/m3)Figure 7-2 Critical bed shear stress as a function of dry mud density(Derived from Mitchener and Torfs, 1996)1Dry density = dry mud mass divided by the volume of wet mud.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-47

A relationship between dry and wet mud density along with corresponding critical bed shear stress isgiven in Table 7-1. The three critical bed shear stresses shown have been used in the analysis thatfollows.Table 7-1Critical bed shear stress and dry mud densityDry Mud Density (kg/m 3 )Approximate Wet Mud BulkDensity (kg/m 3 )Critical Bed Shear Stress (N/m 2 )200 1180 0.69300 1300 1.13400 1400 1.59Simulated (Western Basin hydrodynamic model) bed shear stresses over a period of 430 hours(approximately 18 days) are shown in Figure 7-3 for Sites 4 and 7 (corresponding to Segments 4 and 7),which illustrates that Site 7 experiences considerably greater bed shear stresses than Site 4. Site 7 alsocorresponds to the segment with the highest bed shear stress of the seven segments along the easternwall that are evaluated here. Critical bed shear stresses relating to the three representative dry muddensities (200, 300, 400 kg/m 3 ) are also shown to illustrate the frequency and duration when erosion islikely to occur.2.52Bed Shear Stress (N/m2)1.51Critical BSS = 1.59Critical BSS = 1.13Critical BSS = 0.690.500 50 100 150 200 250 300 350 400Time (hours)EW7EW4Figure 7-3 Modelled BSS for Sites 4 and 7, superimposed on critical BSS for varying muddensity42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-48

The durations over which each of the above critical bed shear stresses is exceeded are presented inTable 7-2. These exceedance values for each of the three critical shear stresses correspond to Sites 6and 7. Since the model simulations were for prevailing conditions combining both a spring and neap tidalevent, erosion duration is also representative of similar tidal conditions. Bed stresses would tend toexceed critical shear stresses for approximately 4 – 15% of the time at Site 7 but for much smallerduration (~ 3%) for Site 6. These values relate to less than 55 days of erosion potential per year.Table 7-2 Critical bed shear stress exceedance for Segments 6 and 7SiteCritical ShearStressPercentExceedanceDaily Exceedance(hours)Yearly Exceedance(days)0.69 15.0 3.58 55Site 71.13 8.3 2.001.59 4.5 1.0830160.69 3.3 0.78 12Site 61.13 - -1.59 - ---Table 7-3 summarises the mud resuspension flux estimates 2 for each segment along the eastern wall.Assuming a critical shear stress for a dry mud density of 300 kg/m 3 of 1.13 N/m 2 , only Segment 7 at thenorthern extent of the eastern wall is predicted to erode. Erosion is not predicted to occur for SegmentsEW1 – EW4. The net sediment flux (sum of sediment fluxes from all segments) indicated for thisscenario is five tonnes per day.It is unlikely that the dry density of partly consolidated mud will differ significantly from the estimates usedhere. If the sediment contains a mixture (for example mud and sand) then the dry density can be higher(Flemming and Delafontaine 2000). Sensitivity tests with lower/higher dry density of mud (200 and 400kg/m 3 ) than adopted here (300 kg/m 3 ) yield critical bed shear stresses for erosion of 0.69 and 1.59 N/m 2 ,respectively.As the mud wave erodes, the bed shear stresses experienced will be smaller (due to increase in waterdepth), and the potential for ongoing erosion will decrease. Therefore the mud wave may not erodecompletely.The equation for the calculation of erosion fluxes is as given below.Erosion Flux (tonnes/day) = M e × ( mod elled- critical) × Exceedance × A/1000;Where M e is the erosion coefficient of mud, modelledis the modelled average bed shear stress over themud wave, criticalis the calculated threshold bed shear stress for mud erosion, exceedance is the2The erosion rate, is given as the erosion constant (0.001 kg/N/s) multiplied by the difference of modelled bed shear stress and thecalculated critical bed shear stress for erosion.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-49

fraction of time (per day) that the modelled BSS exceeds the critical BSS and A is the surface area of themud wave.Table 7-3 presents sediment flux estimates for the range of dry mud densities. In summary, critical shearstresses along Segments 5 – 7 will tend to erode for the lower range of the dry mud density (200 kg/m 3 ),while only Segment 7 would tend to erode for an upper dry mud density of 400 kg/m 3 . Hence, an upperestimate of the total sediment flux for dry density of 200 kg/m 3 is 11 tonnes per day, while a lowerestimate of the total sediment flux is 2 tonnes per day for a dry mud density of 400 kg/m 3 .Therefore, the sediment flux from erosion of the mud mound is estimated to range from 2 – 11 tonnesper day with most of the erosion expected from Segment 7. The south-eastern, northern and westernmud mounds are not expected to erode under typical tidal conditions. The sediment eroded fromSegment 7 is likely to act as a point source owing to its short length.Table 7-3 Analytical modelling of sediment fluxes for critical bed shear stress of 1.13 N/m 2 €Segment NameSegmentLength (m 3 )Mud Volume(m 3 )Mass of Mud(tonnes)Time to Erode(days)SedimentFlux(tonnes/day)EW5 – Site 7 100 1,000 1,300 263 5EW5 –Site 6 100 1,000 1,300 No Erosion -EW5 – Site 5 300 3,000 3,900 No Erosion -EW1 - EW4 500 5,000 6,500 No Erosion -TOTAL SEDIMENT FLUX 5Table 7-4Sediment fluxes based on variations in dry mud densitySegmentNameDryDensity ofMud(kg/m 3 )Critical BSSfor Erosion (N/m 2 )criticalBulkDensity ofMud(kg/m 3 )Mass ofMud(tonnes)Time toErode (days)SedimentFlux (ton/day)EW5 – Site 7200 0.69 1,200 1,200 122 10400 1.59 1,400 1,400 744 2EW5 –Site 6 200 0.69 1,200 1,200 1848 1€ Notes: (1) Dry density of 300 kg/m 3 ; (2) Wet bulk density of mud of 1,300 kg/m 3 assumed; and (3) bed shear stressvalues for the north wall are generally less than 0.3 N/m 2 . Therefore, erosion is not predicted for mud wave formedin this region.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-50

SegmentNameDryDensity ofMud(kg/m 3 )Critical BSSfor Erosion (N/m 2 )criticalBulkDensity ofMud(kg/m 3 )Mass ofMud Time to Sediment(tonnes) Erode (days) Flux (ton/day)400 1.59 1,400 1,400 No Erosion -EW5 – Site 5EW1 - EW4200 0.69 1,200 3,600Significantlylong to erode400 1.59 1,400 4,200 No Erosion -200 0.69 1,200 6,000 No Erosion -400 1.59 1,400 7,000 No Erosion -0.02Total Sediment Flux 2 to 11Effect of Bundwall Dynamic DesignThe potential for any mud wave to contribute to general turbidity will be further moderated by theinfluence of the bund wall stabilisation. As the bund wall batter slope gradually stabilises, material fromthe bund may partially envelope any mud wave offering protection from erosion.7.3 Construction Sequencing and Scour7.3.1 Submission #2Sequencing of construction may significantly influence the turbidity levels and sedimentation overseagrass to the north of the reclamation area, and the extent of scouring of bottom sediments northof the NE corner as shown in the modelling for the FLNE. However, no modelling of the effect ofconstruction sequencing, which is proposed to occur simultaneously in three directions, has beenundertaken. Seagrass will also be impacted by souring of displaced mud ahead of the bund wallconstruction – east of the eastern bund and west of the western bund wall.The statement in Chapter 7 Hydrodynamics: Potential Impacts Affecting Turbidity that there will belittle predicted impact of ongoing turbidity generation as a result of changes to current speeds in theinter- and sub- tidal areas, which decrease with distance north from the reclamation area andproximity to the deeper channels may be correct but draws attention away from the potential shortterm scouring of bottom substrates around the NE corner and in the western intertidal channel.Provide information on the effect on the seagrass of construction sequencing of the bund wall aroundthe entire reclamation area (Western Basin and Fisherman’s Landing Expansion) on tidal currentvelocities; scouring of bottom substrate (including mud displaced by the walls); turbidity levels overthe seagrass communities to the north; and sediment deposition. Further modelling may beappropriate unless the sequencing of construction is changed to clearly minimise impacts.Tidal current velocity elevation in the intertidal channel to the west of the reclamation area may resultin scouring and subsequent elevated turbidity and sedimentation over seagrass. The EIS does not42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-51

consider the potential for such impacts except in the environmental management plan and Chapter20 Summary and Conclusions. The proposed temporary access across the channel could be utilisedto manage flow velocity in the channel, provided that downstream scouring following construction iseffectively controlled.7.3.2 OverviewThe potential for scour to occur is driven by the concern that as the bund wall progresses, two influencesarise. Firstly, the construction of the bund creates a linear extension into Western Bay, and there is thepotential for slightly elevated velocities at the bund face. Secondly, as the bund nears closure(construction having occurred on two or three faces), there is the potential for increased velocities tooccur as the gap narrows. In regions with a high tidal range, a differential between the tide and the waterlevel inside the bund can arise, leading to elevated velocities.7.3.3 Construction Sequencing/Bund ClosureIf the FLNE Project is approved, construction of the bund wall will start with the eastern wall,commencing at the existing Fisherman’s Landing. As described in the WB EIS, construction mayproceed on up to three fronts following Project approval. The locations at which construction cancommence are limited to points of existing access, and the proposed haul route. Hence, there is limitedopportunity to determine which parts of the wall are built in which order. Never-the-less, it is likely thatbund closure will occur along the northern wall, and towards the eastern wall. This will allow closure tooccur in deeper water, which should assist in minimising the potential for scour.This will also facilitate flushing of the Reclamation Area prior to closure, with the closure closer to themain channel allow for greater dilution potential.7.3.4 Scour VelocitiesAdditional modelling work was undertaken to investigate potential velocities arising from different phasesof the construction. Two scenarios were investigated:Construction of the eastern wall only; andThe bund immediately prior to closure.Both simulations are regarded as indicative only, as the permeability of the bund has not been allowedfor, thereby artificially increasing the differential in water level between the inside and outside of thereclamation.Construction of the Eastern Wall Peak velocity plots are provided for flood and ebb phases of a spring tide, with peak velocities higherfor the flood (filling) phase of the tide. A peak velocity of the order of 2 m/s is predicted. The plots indicate elevated velocities around the end of the bund. There is also a broad zone ofincreased velocities coming around and across the shallow area to the north to fill up/empty the openarea behind wall.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-52

Increased velocities can be expected over reduced areas for narrower openings (i.e. as the bundnears closure).It is likely that any scour would lead to a channel forming and velocities then reducing.Modelling the bunds with zero permeability is conservative in terms of peak velocities through theopening as it will maximise the head difference. The actual permeability and resultant velocities willbe dependent on the design and construction material used in the bund walls.Results are provided in graphical format in Appendix C.Bund ClosureA second simulation, representing bund closure, predicted the potential velocities that might arise with anon-permeable bund and a gap of less than 20 m. This suggests velocities of the order of two timesthose shown for the eastern wall only, albeit over a much narrower area. Whilst an over-estimate,velocities of this magnitude would require some form of mitigation. This is discussed in Section 7.4.7.3.5 Bund StabilityThe risk of bund wall failure is very low as it will be appropriately designed.7.3.6 Bund MaterialsThe material to construct the bund wall will consist of graded quarry material and should not pose acontamination threat to the water quality and hence ecology of Port Curtis.7.4 Mitigation Measures7.4.1 Mud WaveMitigation measures associated with any mud wave that forms are problematic, though some measuresare likely. The primary concern is that trying to remove or stabilise the mud wave may cause greaterturbidity generation than leaving it to disperse via natural processes.The mitigation measures considered included:Angling the construction face of the bund, such that a greater portion of the mud wave forms on theinside of the bund face (i.e. within the reclamation). This may not be practical from a constructiveperspective and, nor may it make a difference of any significance.Physical removal of the mud wave. Measures such as drag bars, small CSDs and long reachexcavators were considered. Drag bars are unlikely to be successful, as the drag bar would need tobe offset from the towing vessel. That is, the towing vessel would not be able to operate close to thebund wall. A small CSD runs the risk of striking rocks sitting on the seabed (i.e. rocks that haverolled beyond the bund wall). Long reach excavators offer some potential in shallower waters (e.g.the western wall), and could be of benefit if the mud wave were to exhibit an ASS risk. The use ofsuch an excavator is less likely to be of benefit in deeper waters to the east of the eastern wall.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-53

The placement of filter fabric beneath the bund wall. Again, this is regarded as impractical in areas ofanything other than small tidal ranges, and unlikely to provide sufficient benefit.The excavation of soft sediments prior to placing the bund wall. DERM have indicated that additionalmaterials are not to be removed from within the reclamation. In addition, this would involve thedisturbance of some soils with potential acid sulphate (PASS) characteristics, and would also requireadditional storage capacity within the reclamation.Effect of Bund Wall Dynamic DesignThe potential for any mud wave to contribute to general turbidity will be further moderated by theinfluence of the bund wall stabilisation. As the bund wall settles, the batter slope will gradually slump andstabilise, with material from the bund potentially partially enveloping any mud wave, thereby offeringprotection from erosion.7.4.2 Mitigation of ScourIn theory, some reduction in the ‘scouring potential’ could be achieved at the north-east corner byrounding the corner. However, this modification of the north-east corner was tested in the hydrodynamicmodel, and shown to provide no benefit.Furthermore, it is likely that some armouring and achievement of a ‘dynamic equilibrium’ of the bottomsubstrate in terms of form and composition (e.g. large percentage of coarse material) with the tidalforcing will eventuate.Moving the location of the closure into shallow water is unlikely to provide any meaningful benefit, as theattenuated tidal range within the reclamation, as driven by tidal pumping, will results in low tide levels(with zero permeability walls) being above mean sea level. As such, water flowing outwards maypotentially scour a channel across the intertidal flats until the water level outside rises again.The primary mitigation recommendation is that the point of closure be in deeper water (towards thenorth-east corner), and that at this point, some additional rock is placed on the seabed. It may also bepractical to create a rock sill over a wider gap (say 50 - 100 m), and then progressively complete closurefrom the bottom up via barge, rather than closing a narrow deep gap via truck and dozer. Where feasible,closure of the wall will be carried out during neap tides.As the bund works progresses and the closure point becomes clearer, additional modelling may bewarranted in order to confirm the need to address scouring.7.5 Resuspension7.5.1 Submission #2 The statement that ‘It is likely than any sediments disturbed by the construction of the bund wall thatdeposit over the seagrass beds will be remobilised and transported away from the tidal flats duringtidal movements and elevated wave conditions’ does not adequately address the need to minimiseimpacts, and contradicts reasons stated in the EIS for not including resuspension in modelling ofturbidity in Port Curtis waters resulting from the project (Section 4.2.1 General Assumptions states:42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-54

‘There was no provision for re-suspension of already deposited plume material in the dredge plumeassessments. While there is the potential for re-suspension of the fine suspended load which doessettle out, it will generally become mixed with and hence indistinguishable from the re-suspension ofthe natural bed material’). Large quantities of unconsolidated fine sediments from dredge plumescould be expected to be more readily re-suspended than natural bed material that is partly stabilisedby microbial activity and benthic communities.Though it is likely that the ‘natural’ bed substrate is more stable in seagrass bed areas of the WesternBasin because of biotic factors, the current elevated levels of turbidity in the Western Basin must besourced from other regions not subject to these stabilising biotic factors. For example, the extensiveadjacent intertidal flats of the northern Western Basin are one such likely source of natural backgroundturbidity. It is this component of the turbidity (or TSS) upon which the assumption of dredge plumematerial becoming mixed and indistinguishable from ambient particles is based, not necessarily theimmediate natural bed material on which the seagrass beds grow. It is clear that the shallow regions(with extensive seagrass beds) are highly turbid environments relative to the main channels. As with thedredge plume material, these ‘natural’ particles will also undergo settling on the seagrass beds asunconsolidated material and more readily undergo resuspension than the substrate material below theseagrass beds.Despite the above answer, some consideration has been given to the potential fate of any resuspendedmaterial. This is discussed in Section 7.6.7.6 Potential of Fate Resuspended Dredge MaterialNumerical modelling for the Western Basin did not take into consideration the resuspension of dredgematerial once it has settled to the sediment-water interface. In this section, a qualitative assessment ofthe potential influence of resuspension is therefore provided.Two datasets have been used in the analysis that follows, namely dredge simulations (as described inWB EIS, Volume 3, Appendix J, Table 4-3) and sediment deposition rates.The dredge simulations noted in Table 7-5 have been used to assess the resultant suspended sedimentconcentrations at selected sites (refer Figure 7-4) within the Western Basin. Site 18 and the areasurrounding the proposed northern reclamation wall were generally shown to have the highest TSSconcentrations owing to the combination of decant discharge and TSHD dumping at the rehandling site.Sediment plumes from these simulations tend to have an elongated shape corresponding to the floodebbtidal axis along the northern reclamation wall. Figure 7-5 and Figure 7-6 show maximum TSSdistributions for combinations of simulations.Figure 7-7 demonstrates the spatial patterns of deposition for representative Simulation 8. This indicatesthat most of the material is predicted to settle longitudinally along the tidal axis of the main channel(roughly north-south alignment) as well as along the proposed northern reclamation.As discussed in a previous section, bed shear stresses along the north-eastern portion of the easternreclamation bund may be large enough to cause some erosion of any mud wave that may form.Furthermore, it has been assumed in the above assessment that the largest proportion of dredgematerial composition will consist of mud (silt plus clay). It has also been assumed that soft or partially42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-55

consolidated mud (lighter but clumping or cohesive material) will require similar efforts as that requiredfor sand (heavier but non-cohesive material).Hence dredge material deposited at the water-sediment interface in this region could be resuspended.The uncertainty is whether this would lead to additional turbidity, or whether the same amount ofsediment is resuspended as happens currently. The dredge plume extents indicate that resuspendedmaterial would disperse, with a portion transported to the northern parts of the Western Basin whereresettling is likely.Table 7-5Description of modelled plume scenarios from Table 4-3 (WB EIS Volume 3, AppendixJ)Simulation1Dredge/s – Locations/sLarge CSD – Middle Curtis IslandLarge CSD – North Curtis Island2 Large TSHD Filling - Clinton Bypass3 Large TSHD Filling - Fishermans Landing Swing Basin4 Large TSHD Filling - Targinie Channel5 Medium CSD – Rehandling Location6 Large TSHD Dumping - Rehandling Location7 Large CSD - Laird Point8Large CSD - Fishermans Landing (North)Large CSD - Hamilton Point42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-56

Figure 7-4 Locations where TSS time histories are provided42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-57

Figure 7-5 Maximum TSS Extents for Simulations 1, 3, 5 and 6Figure 7-6 Maximum TSS Extents for Simulation 842/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-58

Figure 7-7 Dredge plume deposition rates for Simulation 87.7 Mud Wave FateShould a mud wave form, it is expected that bed shear stresses in excess of 1.13 N/m 2 would be capableof erosion and suspension of this material (refer Section 7.2 for details). Depending on the actual drymud density, it is estimated that as little as two or as many as 11 tonnes of mud wave resuspensioncould be eroded each day, primarily at the northern extent of the eastern wall.On the basis of sedimentation and TSS patterns from simulations of the fate and transport of dredgeplume material, the likely path of the resuspended mud plume is along the northern wall (east-west axis)and along the western boundary of the main channel (north-south axis) as illustrated in Figure 7-7. Theprediction of the fate of resuspended mud wave material originating from the north-eastern corner of thereclamation is based on Simulation 8, which represents a dredge operating from a similar location – i.e.at the northern end of Fisherman’s Landing.It should be noted however, that all dredge simulations exhibit similar trends, with turbidity aligned to theprimary direction of tidal flow.Assuming a mud wave forms, the greatest erosion is likely to occur at north-eastern end of the easternwall in close proximity to the dredge site of Simulation 8. The mud wave plume will most likely propagateeast along the northern reclamation bund (flood tide) or north (flood tide) or south (ebb tide) along thewestern margin of the Main Channel.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-59

7.8 TSS Source FluxesA comparison of the sediment flux from various sources, including that from erosion of a mud wave, isshown in Table 7-6. This highlights that the decant source is a small component compared to the directsources from the dredging activities (~1% of TSHD, 10% of CSD). Secondly, the TSHD activities areapproximately 10-fold greater than the CSD on a per unit basis. Erosion of the mud wave caused byconstruction of the bund wall is estimated to be of the same order of magnitude as the CSD decant. Assuch, sediment fluxes from the mud wave are expected to contribute the lowest daily total suspendedsolids in the water column under ordinary tidal conditions.Table 7-6TSS source fluxesDredge Method TSS (g/m3) Q (m3/s) Flux (kg/s)Duration(hours/day)Mass Flux (ton/day)Erosion of Mud Wave ~ 2 2 - 11Decant CSD dredging 100 2.5 0.25 24 22Decant CSD rehandling 100 1.25 0.125 24 11CSD (dredge/rehandle) 4 24 346TSHD Overflow 75 8 2160TSHD Dumping 340 1.3 1632The above table provides a strong indicator as to which sources will demand the greatest mitigationeffort, and also reinforce that in this case, mud wave derived turbidity is estimated to be the smallest ofthe various sources.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document7-60

8. Turbidity Duration and Water Quality8.1 OverviewThis section addresses those submissions associated primarily with water quality. This encompasses:Water quality objectives;Proposed decant location;Stormwater management; andSediment and elutriates.Discussion with respect to the occurrence and impacts associated with increased turbidity are providedin Chapter 9.8.2 Water Quality Objectives8.2.1 Discharge Limits for DecantSubmission #2 The EIS discharge limit for the turbidity of dredge spoil drain water of 100 NTU (350 mg/L TSS) is notconsistent with best practice or protection of the values of the receiving water. The proposeddischarge limit for turbidity greatly exceeds established limits for other discharges to Port Curtis.Recommend conditions of approval for discharge water quality discharge are included in Attachment3.Submission #11 Turbidity guidelines are set at 6 NTU and 20 NTU respectively for the CWQG and ANZECC. Page 7-33 states the baseline median result for surrounding receiving waters is 9 NTU therefore the adjacentdecant receiving objective should be made to deliver water of similar quality back into theenvironment. Ensure required number of decant cells to produce decant/effluent with turbiditydischarge value of

will operate at the same time as up to 4 dredgers will be operating, and hence, its impact will generallybe masked by the dredge plumes. A recommended approach is offered below.It is recommended that the water quality objective for the decant (i.e. immediately prior to discharge) beset to 30 NTU for the 80 th percentile of monitoring measurements. In support of this recommendation, itis noted that:the receiving waters are predicted to be influenced by dredge plumes;the decant waters will rapidly undergo a large degree of mixing with the ambient receiving waters;in the long term, turbidity of

Ecologically significant triggers for Port Curtis seagrasses do not currently exist. Therefore, referencehas been made to the median and 80%ile values of measured water quality data.Loggers deployments at Sites WQ01 to WQ04 (refer to WB EIS Figure 7.1, which has been reproducedin this document as Figure 8-1) have continued to monitor turbidity and will be subject to ongoingevaluation as further data is collected.The WB EIS currently has site specific turbidity objectives for representative high (Western Basin) andmoderate to low (Narrows, Wiggins Island) impact sites for seagrass beds. The locations of these siteswere shown in Figure 7-4 of the WB EIS, which has been reproduced in this document as Figure 8-1.Sites are designated as WBMxx, where WBM denotes Western Basin Model. Hence, it can be seen thatthe locations represent points where model output has been generated and reported.By way of example, in the EIS adoption of the 80 th percentile TSS (derived from turbidity loggermeasurements) as the site specific water quality objective criteria (after conversion of turbidity to TSSwith the adopted relation), would yield the following WQOs:At location WBM04 (Middle Western Basin seagrass beds) the turbidity objective as defined by the80 th percentile turbidity of the representative logger data is 17 NTU or a TSS of 45 mg/L. Theseagrass beds in the Narrows have also been assigned this turbidity objective because norepresentative logger data is available at this site;At location WBM17 (North Western Basin seagrass beds) the turbidity objective as defined by the80 th percentile turbidity of the representative logger data is 24 NTU or a TSS of 70 mg/L; andAt location WBM09 (Wiggins Island seagrass beds) the turbidity objective as defined by the 80 thpercentile turbidity of the representative logger data is 25 NTU or a TSS of 74 mg/L.The 80 th percentile objective is the ecologically significant objective or trigger value. These data arebased on past logger measurements that were not made during the EIS monitoring and account forsome wet season values.The 80 th percentile turbidity objective for deeper (channel) areas was 10 NTU for the dry season on thebasis of 8 of the 10 monitoring sites or a TSS of 19 mg/L. As mentioned previously, this turbidityobjective may be updated following the acquisition and analysis of the current year’s wet season loggerdata.Reference should also be made to Chapter 17 regarding the future creation of a Dredge ManagementPlan and plans for construction phase monitoring in order to provide a linkage with dredging activities.8.2.4 Lower Estuary GuidelinesSubmission #2 TP (ug P/L) for enclosed coastal water (CWQG 2006) is stated as 25. The figure should be ‘20’.Chlorophyll-a (ug/L) for enclosed coastal waters (CWQG 2006) is stated as 4. This should be ‘2’.In the EIS, the TP and Chla guideline values were selected on the basis of classification of the ProjectArea as the middle reach of an estuary rather than the lower estuary or enclosed coastal waterclassification. As such the proposed corrections are agreed.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document8-63

310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0007,374,000KangarooIsland!

310,000!. WBM01312,000314,000316,000318,000320,000322,000324,000326,000328,000330,0007,376,0007,376,000WBM02!.WBM14!.7,374,000KangarooIslandThe NarrowsWBM15!.Graham Creek7,374,000Friend PointWBM03!.Laird Point7,372,0007,370,000WBM19!.WBM16!.WBM17!.WBM04!.WesternBasin WBM18!.#*!(!(WBM21!.WBM06!.WBM23!.Curtis IslandPelican BanksWBM12!.7,372,0007,370,000!

8.2.5 Water Quality PercentilesSubmission #2Base the water quality objective for suspended solids and turbidity for Port Curtis waters on the 80thpercentile of natural background levels, consistent with ANZECC guidelines and the QWQG.It is agreed that turbidity/TSS water quality objectives (WQO) should be based on the 80 th percentilemeasurements.Submission 2 The EIS states that the turbidity objectives are based, predominately, on dry season, continuouslogger measurements, and recommends wet season logger deployment in both deep and shallowwaters to enable wet season turbidity objectives to be developed.Wet season monitoring results will also shortly be available for loggers deployed primarily in the mainchannels.8.3 Decant8.3.1 Decant Location SubmissionsSubmission #2 Recommendation to direct turbid waters into the main channel and away from the seagrasscommunities and lessen scouring at the discharge point. Modelling shows significant elevation ofturbidity over seagrass to the north of the reclamation area a result of the discharge of high turbiditydrain water. This would be exacerbated by the discharge point in the west rather than the easternside of the reclamation area.Submission #2 As the reclamation area is intended to join the Fisherman’s Landing Northern Expansion, co or jointlocationat the north east corner (eastern bund wall)would be highly desirable as it would direct turbidwaters into the main channel and away from the seagrass communities and lessen the risk ofscouring at the discharge point.Submission #2 Discharge at the north-western corner would maximise impact on seagrass communities due to theelevation of turbidity. Discharge of drain water at the NE corner appears to be feasible and highlydesirable as it will direct turbid waters into the main channel away from the seagrass communities,and minimise scouring at the discharge point. It is recommended to amend reclamation constructionplans to provide for discharge of all dredge spoil drain water and stormwater from any part of thereclamation not fully stabilized, and with appropriate storm water quality management systems, at asuitably designed discharge point at the northern end of the eastern wall of the FLNE.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document8-66

Submission #2Modelling shows significant elevation of turbidity over seagrass to the north of the reclamation areaas a result of the discharge of high turbidity drain water, which is made worse by the location of thedischarge point in the west rather than the eastern side of the reclamation area.8.3.2 Decant Location ResponsesIn the WB EIS, the proposed decant outfall location was near to the north-west corner of the reclamation,on the basis that the long term stormwater management system would have a pond near this location.The current plan for the location of decant outfall has been modified in response to submissions. Thelocation of the reclamation decant discharge point will be adopted at the north-eastern corner of thereclamation to reduce seagrass impacts because of greater dilution from proximity to the main channelflows, and increased distance from many of the seagrass beds.The stormwater management pond is still planned for the north-west corner. This keeps it in closeproximity to where flood flows from the various creek systems will ultimately discharge. The continuousrate of discharge associated with the period of construction will be much higher than any low flowdischarges from the stormwater pond, post construction.Hence, at the time of greatest concern (i.e. during dredging), the location of the reclamation decantdischarge point will be adopted at the north-eastern corner of the reclamation in order to encourage theresultant plume towards channel areas, and away from existing seagrass beds.In relation to the fourth point above, it is noted that the primary cause of turbidity over the seagrass to thenorth of the reclamation is rehandling and not the decant. This is clearly evidenced in the additionalmodel results that have been produced. Maps have been produced in Appendix C.8.4 Tidal Channel8.4.1 SubmissionsSubmission 18 The plots in Figure 4-30 identify that the flattening of the water level response in the 40 m channelwest of the reclamation, due to the reclamation, will cause incomplete tidal water drainage from thesouthern end of the western channel, and to lesser degrees along the channel in a northerlydirection.Cumulative Impacts and Mitigation Strategies – This section proposes, if required, considerationcould be given to dredging one or more shallow channels connecting the channel between thereclamation and the western foreshore though the northern embayment to the main eastern channel.There appears to be no discussion on alternative designs or methodology to identify the constructionof the western channel as the best environmental option. As a precautionary action to ensureimpacts to tidal lands and marine plants located west of the Reclamation Area are minimised, thedredging of ‘one or more shallow channels’ proposal through the northern embayment should bethoroughly explored. Please provide clarification of the potential for dredging one or more shallowchannels as proposed in 5 to accommodate deficiencies in 4.9.1.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document8-67

Please undertake modelling of the above mentioned channel’s and provide details of performance indelivering more effective drainage of the western channel. Please also include details of the impactsupon marine flora, fauna and bare substrate. Please also discuss the potential for maintenancedredging of the channels.Please provide details of the potential impacts to marine plants and tidal lands, including salt marsh,within and adjacent to the portion of the channel subject to incomplete drainage, for a scenario whereno additional drainage is taken.8.4.2 ResponseThe flattening of the water level along the western channel is an artefact of imposing the reclamationfootprint over the existing bathymetry. This approach yielded an elevated sill in the middle of the westernchannel. If the sill is removed then flushing of the western channel will occur and the flattening of thewater level pointed out in the submission will not occur to such a degree. Hence, the need for drainagechannels along the remnant northern extent of the Western Basin is not required.The need for the removal of elevated spots within the channel will be assessed following completion ofthe western bund wall. Any levelling required will be carried out in conjunction with any mud waveremoval requirement.8.5 Elutriates and Sediment Quality8.5.1 PAH and PCB Elutriate QualitySubmission #11 PAH and PCB testing – discrepancy in results. Suggested solution is to perform testing again onsamples to gain accurate results.There is no discrepancy in the test results.As reported in Appendix J of the WB EIS, one hundred of the one hundred and twenty-one elutriatesamples were analysed for polychlorinated biphenyls (PCBs) shown in Table 8-1. None of these samplesexceeded their respective limits of reporting.Table 8-1PCBs limits of reportingSpeciesArochlor 1016Arochlor 1221Arochlor 1232Arochlor 1242Arochlor 1248Arochlor 1254Limit of Reporting0.1 μg/L0.1 μg/L0.1 μg/L0.1 μg/L0.1 μg/L0.1 μg/L42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document8-68

SpeciesArochlor 1260Total PCBsLimit of Reporting0.1 μg/L0.1 μg/LOne hundred of the one hundred and twenty-one elutriate samples were analysed for PAHs and phenols(Table 8-2). None of these samples exceeded their respective limits of reporting, apart from one sample(of 100) at Site 1A-063 in dredge area 1A. Table 8-3 summarises the data recorded at Site 1A-063,which were primarily at the limit of reporting.Table 8-2PAHs and phenol species and limits or reportingSpecies Limit of Reporting Species Limit of Reporting3-methylcholanthrene 0.1 μg/L Chrysene 0.1 μg/LAcenaphthene 0.1 μg/L Dibenz(a,h)anthracene 0.1 μg/LAcenaphthylene 0.1 μg/L Fluoranthene 0.1 μg/LAnthracene 0.1 μg/L Fluorene 0.1 μg/LBenz(a)anthracene 0.1 μg/L Indeno(1,2,3-c,d)pyrene 0.1 μg/LBenzo(a) pyrene 0.05 μg/L Naphthalene 0.1 μg/LBenzo(b)fluoranthene 0.1 μg/L Pentachlorophenol 0.1 μg/LBenzo(g,h,i)perylene 0.1 μg/L Phenanthrene 0.1 μg/LBenzo(k)fluoranthene 0.1 μg/L Pyrene 0.1 μg/LTable 8-3 PAHs and phenols at site 1A-063SpeciesConcentration (μg/L)Acenaphthene 0.1Acenaphthylene 0.1Anthracene 0.1Benz(a)anthracene 0.1Chrysene 0.1Fluoranthene 0.1Fluorene 0.1Naphthalene 0.2Phenanthrene 0.1Pyrene 0.142/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document8-69

8.5.2 Manganese Elutriate QualitySubmission #11Intention to monitor ‘natural’ levels of manganese. Is this a case of monitoring for monitoring sakes?Review purpose of monitoring of the element or explain its importance better in the document.The elutriate testing for the WB EIS indicated that ammonia and manganese were the only elementsgreater than the ANZECC (2000) toxicity levels for marine ecosystems. Hence, it was deemed prudent tomonitor that manganese (and ammonia) levels were diluted to below toxic thresholds.8.5.3 Contaminant Resuspension Submission and ResponseSubmission #11There is a concern about resuspending contaminants in the project area and the effects onecological processes. Suggested solution is rather than just following NAGD perhaps showinggreater commitment to prevention of environmental damage by including this in the monitoring of theproject site and surrounds.The potential for contamination of resuspended dredge plume material is low as illustrated by theextensive sediment and elutriate sampling of the proposed dredge volume that shows ‘clean’ sediments.Further, water quality monitoring of the decant outfall and sites in the Project Area will detect whethermobilisation of contaminants by the Project occurs.8.5.4 Sediment Quality Risk AssessmentSubmission #6The majority of the table notes medium level risk in terms of sediment quality. What are the mediumto long-term implications for marine species such as prawn due to sediment quality?The long-term implications for the marine environment beyond the Project boundary are minimal. Thedredge plume is contained within the enclosed waters of Port Curtis.There is not expected to be any long-term degradation to sediment quality.After the completion of dredging activities, the turbidity climate of the enclosed waters of Port Curtis ispredicted to return to a similar state after the after several e-folding flushing time scales (e.g. 2-3months).8.5.5 Elutriate Ammonia Submission and ResponseSubmission #2Provide further information on potential levels of ammonia in the water column, which could resultfrom overflow dredging of sediment containing high levels of ammonia in elutriate, have particularregard for the ANZECC toxicant guideline. If potential ammonia levels and/or extent of high isdetermined to be unacceptable for protection of marine biodiversity, mitigation strategies should bedefined. Strategies for sediments with high ammonia content could include use of a cutter suction42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document8-70

dredge rather than trailer suction hopper dredge (TSHD), or non-overflow dredging by TSHD withdirect discharge to the reclamation area.The 95 th percentile ammonia elutriate value is 5,820 ug/L on the basis of 33 measurements, substantiallyhigher than the median (1,000 ug/L) used in the WB EIS. Several improvements to the elutriate dilutionmodel during TSHD overflow or dumping operations were incorporated. Firstly, inspection of dredgeplume widths from recent operations indicate that a characteristic width scale is 100 m rather than 50 m.Secondly, most of the overflow and dumping activity will occur in 10 m depth of water rather than 5 m.Thirdly, current advice is that there will be limited overflow (of the order of minutes) associated with thedredging of fine sediments. These refined assumptions, along with the use of the 95 th percentileammonia elutriate values yields the results in Table 8-4.Table 8-4Tidal currentsTidal Current (m/s)OverflowRatio relative to EcologicalGuideline (CWQG 2009)Ratio relative to Toxicity Guideline(ANZECC 2000)0.1 – Slack 16.2 0.1430.5 – Moderate 4.2 0.0371 – High 2.5 0.022Dumping0.1 – Slack 26.6 0.2340.5 – Moderate 6.6 0.0581 - High 3.7 0.033A 15-25 fold increase over the QWQG (2009) ecological guideline values of 8 ug/L occurs during slacktides (downstream distance from TSHD is 60 m for dumping and 300 m for overflow). In contrast only a2-4 fold increase over the QWQG (2009) guideline occurs during high current speeds (downstreamdistance from TSHD is 600 m for dumping and 3000 m for overflow), However, ammonia levels are only15-25% of the ANZECC (2000) toxicity guideline value of 910 ug/L for ammonia after dilution of the 5,820ug/L 95 th percentile ammonia elutriate concentration with the background levels of 6 ug/L. Hence, interms of ammonia toxicity elutriate loading is a low risk, but is of more concern in causing elevatednutrient levels in an ecological (i.e. elevated nutrient levels) context.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document8-71

9. Dredging Water Quality9.1 Turbidity ImpactsThis chapter provides a linkage between the various causes of elevated turbidity, and the implications ofthose elevations. In particular, this chapter provides a response to those submissions that focus on theeffects of turbidity.In the previous two chapter, the sources of turbidity (primarily dredging and rehandling, but alsopotentially turbidity associated with mud wave, scour, and resuspension) were addressed.Reference is also made to light attenuation, which is one of the factors influencing seagrass health.Elevated turbidities arising from the dredging campaign will be the primary cause of light attenuation overthe duration of the dredging campaign, which will in turn lead to some short to medium loss of seagrass.This loss has been catered for through the provisions of an offsets package, which is referenced inChapter 12.Other relevant chapters include Chapter 5 (Dredging Methodology) and Chapter 18 (Rehandling andOffshore Disposal), each of which provide details of how mitigation measures can be implemented toreduce the predicted turbidity (and degree of light attenuation) that is discussed in this chapter.The additional quantification of areas of seagrass affected is provided in Chapter 10 (EcologicalImpacts).However, it is also important to recognise that seagrass communities are somewhat ephemeral, withtheir status influenced by annual temperature, cloud cover, flood events, and other natural phenomena.9.1.1 Submission #2Although the EIS shows the extent of potential increases in turbidity and sedimentation, it does notquantify the actual impact on seagrass. The modelling does not address resuspension and containsconflicting statement in relation to the potential for resuspension. Given that the sedimentation inshallow waters may be up to 12 cm/year for the modelled scenarios, resuspension of theseunconsolidated sediments may result in significant elevation of turbidity. If the deposited sediment isnot resuspended, the smothering effect may be significant.Prolonged elevation of turbidity and sedimentation resulting from several years of dredging and drainwater discharge, scouring by increased tidal currents and displaced mud around the reclamationarea, and an unknown level of resuspension in shallow waters, is likely to have significant adverseimpacts (especially during bund wall construction and Stage 1A and 1B dredging) including loss ofdiversity and abundance of seagrass caused by impaired photosynthesis as a result of reducedwater clarity (above natural variation) and smothering of leaves by settling out of suspendedsediments; loss of macrobenthos through clogging of feeding apparatus by extraneous suspendedmatter; and loss of habitat and food sources for fisheries species and higher order species, such asdugong and turtles.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document9-72

Although the EIS contains information showing the extent of potential increases in turbidity andsedimentation, it does not quantify actual impact on seagrass. Nor does the modelling includeresuspension and contains conflicting statements in relation to potential resuspension. Given thatsedimentation in shallow waters may be up to 12 cm/year for the modelled scenarios, resuspensionof these unconsolidated sediments may result in significant elevation of turbidity. If the depositedsediment is not re-suspended, the smothering effect may be significant.It is accepted that impacts to the ecological communities as commented will occur and will be mitigatedfor through offsets. Further, it is accepted that impacts to the ecological communities in front of thedecant discharge outlet and throughout the Western Basin seagrass beds from TSHD overflow andrehandling activities could be substantial and will have to be mitigated for through offsets, or through thereduction in either or both activities.Though it is likely that the ‘natural’ bed substrate is more stable (in terms of resuspension potential) inseagrass bed areas of the Western Basin because of biotic factors, the current elevated levels ofturbidity in the Western Basin must be sourced from other regions not subject to these stabilising bioticfactors. For example, the extensive adjacent intertidal flats of the northern Western Basin are one suchlikely source of natural background turbidity. It is this component of the turbidity (or TSS) with which theassumption of dredge plume material becoming mixed and indistinguishable from ambient particles isbased, not necessarily the immediate natural bed material on which dense meadows of seagrass bedsgrow. It is clear that the shallow regions (with extensive seagrass beds) are highly turbid environmentsrelative to the main channels as documented through past logger deployments by Central QueenslandUniversity. As with the dredge plume material, these ‘natural’ particles will also undergo settling on theseagrass beds as unconsolidated material and more readily undergo resuspension than the substratematerial below the seagrass beds.As highlighted immediately above, though seagrass beds contribute to lower fluxes of resuspension ofbed material, turbidity source areas (such as the extensive intertidal regions of the northern WesternBasin) are likely to be high source areas. The Western Basin region is a naturally turbid system, whichforms the basis for the assumption that once dredge plume material settles out of the water column it is‘indistinguishable’ from the ambient settled particles, as material from these other regions are alsoundergoing settling and resuspension over the seagrass beds.In summary, there will be an impact # to seagrass beds because of a decrease in the light climate fromelevated turbidity levels. Further, in some regions potentially high sedimentation rates will cause somedegree of smothering. Locations most likely to be impacted are expected to be immediately to the northof the reclamation, especially if rehandling is required for all material dredged by TSHD. Lesser impactsare expected with respect to at the point of decant discharge at the north-eastern corner of thereclamation. Simulated dredging operations indicate that the southern half of the remnant Western Basinseagrass beds will be impacted to some extent, particularly by TSHD dumping at the rehandling site.These ‘predicted’ losses/impacts to seagrass beds in the Western Basin will be mitigated through theoffsets package.#The impact could range from short term to permanent in some instances.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document9-73

9.1.2 Submissions #3 and #4The level of uncertainty in the prediction of the impacts from dredge plumes and whether or not theseagrass exposed to these plumes can survive is of concern to Council. If only the area to the northof the proposed reclamation dies, then the total lost would represent 11.2% of Port Seagrass.Clear conclusions should be drawn on the impacts of sediment plumes and increases in turbidity onseagrass beds, including their duration, and a clear indication should be made as to how waterquality trigger levels will be established and how they will enable adjustment of dredging worksbefore sensitive habitats are negatively affected. Additional information required on both dredgedisposal during flood tides and use of overflow dredging.The following is proposed to decrease the impacts to seagrass beds arising from the Project:For unavoidable loss of seagrass beds offsets will be used as mitigation.Water quality objectives for the decant from the reclamation have been decreased from the 95 thpercentile of turbidity logger based measurements to the 80 th percentile, which will lessen the impacton seagrasses.The reclamation decant will be placed at the north-eastern corner which will yield greater dilution andtransport away from the Western Basin seagrass beds relative to the original positioning in the northwesterncorner of the Reclamation Area.A monitoring program will be developed and turbidity trigger values developed as part of the DredgeManagement Plan to guide dredging operations to reduce impacts. The logger based monitoringprogram will have regular periodic downloads of data with immediate data processing within 1 weekof data acquisition. A simple statistic such as the median will then compared to the 80 th percentile ofthe baseline data. If the median is below the 80 th percentile for the relevant location, then no action istaken. If the median is greater then a suite of actions takes place including:– A greater frequency of data logger download;– Movement of the dredge to another location to lessen the impact at the site that is non-compliantwith the turbidity trigger value; and– Utilisation of alternative dredge disposal methods to reduce impacts.The Dredge Management Plan will have a number of operational responses to improve turbiditylevels at sensitive ecological receptors (e.g. seagrasses) such as:– Direct pumping from CSD dredging with use of a controlled network of discharge points willprovide optimal flow rates to allow sufficient reduction in turbidity in the Reclamation Area prior todecant discharge;– Implementation of internal baffles and weir boxes as relevant in order to prolong residence time,and meet the water quality objective;– Provision of contingency to be able to move TSHD operations between at least 2 sites to allowseagrass beds that are undergoing prolonged impacts to have some form of respite viaprogrammed movement of the dredge plant;– The minimisation of overflow when dredging fine silts and clays. Periods of overflow will besubstantially shorter than when coarser materials are being dredged;42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document9-74

– Direct pumpout from the TSHD hopper (when clay content is less than 30%) to reduce spoildumping and rehandling plumes levels; and– Utilisation of existing offshore spoil ground in association with TSHD operations.The model simulations clearly indicate that a quasi-steady-state is reached with the intensity of proposeddredging over the two month duration of the simulations. Hence, the duration of the impacts will roughlycoincide with the duration of each stage (1A, 1B, 2 and 3) of dredging. Further, the simulations provide aworst case scenario with rehandling and simultaneous dredging with 4 dredgers in some cases (twoCSDs dredging, one TSHD overflow and dumping, and one CSD rehandling).Revised estimates of the Project’s dredge volume indicate that up to 45 Mm 3 of material will be dredged,with most of this to be conducted using CSD. Of this total, a small portion will be dredged using TSHD.Within Stages 1a and 1b, the component to be dredged by TSHD will be of the order of 5 to 6 Mm 3 .Additional material may be dredged by TSHD for Stages 2 and 3, though this is uncertain.As TSHD dredging is generally more time efficient, the TSHD dredge operation is likely to occur forperhaps 20% of the duration of the CSD dredging. Hence, impacts are likely to be of a shorter durationthan initially considered in the EIS.It is also clear from the simulations that dumping from the TSHD in front of the reclamation during a floodtide will yields elevated turbidity over the Western Basin seagrass beds. Hence, a hybrid option to pumpout the TSHD hopper when it arrives during flood tides (if clay content allows) and to bottom dump duringebb tides will be adopted where material properties allow.It is recognised that overflow dredging is a large source of turbidity that results in impacts to seagrassbeds in close proximity. Revised estimates of the amount of TSHD dredging are substantially lower and amuch larger proportion of the dredging is being planned with CSD that generates considerably loweramount of dredge plume material into the water column.9.1.3 Submission #11There is an inconsistency when discussing the projects effect on turbidity. The area is described as‘well mixed body of water’ yet on page 75 it mentions turbidity will most affect deep channels.Removal of the sentence or revision of the language used. Clarify the projects net effect on turbidityin the project area.The term ‘well mixed body of water’ refers to no (or small) variations in water quality vertically through thewater column, say between the surface and bottom. However, Port Curtis (as all estuaries) generally haslarge horizontal variations in water quality.The net effect of increased turbidity in the Project Area cannot be encapsulated simply as some areaswill not be affected whilst others to a greater degree. For example, further analysis of the monitoring dataand modelling is being used to set water quality objectives for turbidity at different levels throughout theProject Area to base triggers for operational actions in terms of dredging.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document9-75

9.1.4 Submissions #6 and #12What are the medium to long-term implications for the marine environment beyond the projectboundary?TSHD overflow can cause sediment plumes into Keppel Bay which may impact the Great BarrierReef. The SE to SW flow pattern of sediment-laden seawater from the Narrows or Port Curtis areamay reach the Keppels and impact corals. Suggested solution is to use non-overflow method forTSHD operations.The model predictions clearly show that the sediment plumes will not impact the Great Barrier Reef, andwill be constrained primarily to Port Curtis waters.There will not be any plumes to Keppel Bay. The bulk of dredging will be conducted using CSD, whichdoes not operate with an overflow mode.9.1.5 Submission #18On page 22 it is suggested that there may be an increase in the northward propagation of the dredgeplume over the main EIS model into Graham Creek and the Narrows. This has the potential to furtherimpact on seagrasses as meadows are located in both these locations. Recommendation: Pleaseupdate further modelling of the potential dredge plume extending into Graham Creek and theNarrows, generated by dredging of options 1b or 2a, and provide a report of the findings.Further analysis of the model simulations at several locations in The Narrows is provided in Table 9-1.Table 9-1Comparison of 50 th , 20 th , 10 th and 5 th probability exceedance of TSS at key locationsin The Narrows for each scenario with and without rehandlingGrey shading denotes exceedance of the 80 th dredge plume TSS objective.With RehandlingWithout RehandlingSite andScenarioTurbidityObjective80 th % ile Median20 th %Exceed10 th %Exceed5 th %ExceedMedian20 th %Exceed10 th %Exceed5 th %ExceedWBM01 (UpperNarrows)Scenario 1a 29 5 12 15 17 1.5 3 4 5Scenario 1b 29 7 18 30 35 3 9 19 23Scenario 2 29 5.5 15 19 23 2 7 8 11Scenario 3 29 1 3 4 4.5 1 3 4 4.5WBM02(Western Arm ofUpper Narrows)Scenario 1a 29 3 8 12 14 1 2 3 3.542/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document9-76

With RehandlingWithout RehandlingTurbiditySite andObjective20 th % 10 th % 5 th % 20 th % 10 th % 5 th %Scenario 80 th % ile Median Exceed Exceed Exceed Median Exceed Exceed ExceedScenario 1b 29 4 12 20 27 2 6 10 16Scenario 2 29 3.5 10 15 18 1.5 4 6 7Scenario 3 29 1 2 3 4 1 2 3 4WBM14 (MiddleNarrows)Scenario 1a 29 7 12.3 17.5 19.5 2 4 6 7Scenario 1b 29 10.2 29 35 39.5 6 18 24 27Scenario 2 29 10 20 26 29.5 5 9 15 18Scenario 3 29 1.5 2 2.1 2.2 1.5 2 2.1 2.2WBM15 (LowerGraham Creek)Scenario 1a 29 6.5 14.8 17.5 18 3 8 10 11Scenario 1b 29 10 21.5 23 24.5 7 15 18 19Scenario 2 29 7.5 14 17 18.5 4 7 10 12Scenario 3 29 1.5 2.3 3 3.5 1.5 2.3 3 3.5The model results through the area of interest clearly demonstrate that the median value (with andwithout rehandling) meets the 80 th percentile turbidity objective.9.2 Impacts to Underwater Light Climate9.2.1 Submission #2 Seagrass species identified in the EIS, Zostera capricornia and Halophila ovalis have criticalthreshold limits for light availability. Available studies indicate critical threshold limits of 30% surfaceirradiance (SI) and 16% SI, respectively. Project reductions in light availability indicate seagrassesmay be at risk given the drop in irradiance levels down to 1.6% irradiance at 2 m depths in theNarrows and 2.6% SI at 2 m depths at Wiggins Island (Table 6-7 of Appendix K of the EIS).The light impacts for Scenarios 1A, 1B and 2 with rehandling (which are all similar) at key seagrass bedlocations are summarised in Table 9-2. Details for all locations can be found in Appendix D. Theseestimates assume a background median turbidity of 9 NTU (or 15 mg/L TSS). Seagrass beds at 1, 1.5and 2 m below mean sea level (MSL) are predicted to have 30%, 15.2% and 5.3% of surface irradianceunder median natural background turbidity levels. Hence, Zostera capricornia would be expected toinhabit the 0-1 m below MSL water strata and Halophila ovalis the 0-1.5 m below MSL water strata.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document9-77

Neither would be expected to exist at 2 m below MSL on the basis of this submission’s quoted referencevalues.Further, inspection of Table 9-2 shows that there is a small predicted decrease in surface irradiance atthe Narrows and Wiggins Island due to dredging activities associated with the combination of CSD,TSHD (overflow and rehandling) and decant discharge for Scenarios 1A, 1B and 2 (note all of similarmagnitude with operation of full time TSHD overflow and rehandling, but at different locations). Incontrast, particularly for 1.5 below MSL the surface irradiance is effectively halved in the north andmiddle Western Basin representative seagrass beds, thus undergoing a much greater impact.Given the comment’s references regarding surface irradiances of 16% and 30% as thresholds for lightavailability of 2 key seagrass species it follows that:Neither of these seagrass species would exist at 2 m below MSL even for ambient conditionsbecause light is currently too low;One of the species (16% surface irradiance threshold) may be acutely affected in the Western Basinand chronically affected in The Narrows and Wiggins Island locales at 1.5 m below MSL, but notaffected at 1 m below MSL; andOne of the species (30% SI threshold) may be chronically affected at the Western Basin sites at 1 mbelow MSL, but considerably less so at The Narrows and Wiggins Island.Table 9-2 Light impact summary for Scenarios 1A, 1B and 2Depth (m) Back/ ground Narrows WigginsIsland% of Incident PAR at SeabedNorthWesternBasinMiddleWesternBasin1 30.0% 26.2% 27.5% 22.1% 20.4%1.5 15.2% 11.7% 12.8% 8.3% 7.1%2 5.3% 2.9% 3.7% 1.1% 0.7%9.3 Other Issues9.3.1 FlushingSubmission 11 This project will directly and indirectly disturb a significant percentage of sea bed within this wetland.The effects it will cause are not appropriately described and should never be described as ‘minorpredicted changes’ as this is highly subjective. Removal of the sentence from the EIS or revision ofthe language used. Provide evidence as to how the subjective statement was concluded i.e. what arethe scientific results and evidence that support and provide reason to conclude and predict ‘minor’changes?.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document9-78

The use of ‘minor predicted changes’ in terms of the flushing regime of the Project Area is predicatedupon the results of the quantitative hydrodynamic modelling as detailed in the WB EIS.9.3.2 Sediment Quality GuidelinesSubmission #11 Difficulty experienced using document to compare findings against the allocated/stipulated guidelinevalues. Revise table layout to make more user friendly and east to interpret.The table referred to provides three relevant guidelines for a number of sediment quality parameters, andas such provides the information in an informative manner.9.3.3 Sediment Quality Risk AssessmentSubmission #14Table 7-13 sediment quality risk assessment. Medium level risk of sediment quality is too great aburden to be placed on the marine life in the area. Suggested solution is for GPC to take measuresto ensure the long term viability of the seagrass beds the dugong feed on. Dugongs are a listedthreatened species.The risk of sediment quality issues arising from the Project on the basis of consequence and likelihoodhas been assessed as medium risk. The sediment quality of the proposed dredge volume with theProject Area has undergone extensive sampling and laboratory analyses. The findings on the basis ofthese sediment analyses in compliance with NAGD (2009), is that a low to medium risk is posed tosediment quality.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document9-79

10. Ecological Impacts10.1 Benthic Habitat Impacts10.1.1 Submission #2The EIS shows the extent of the potential increase in turbidity and sedimentation but does notaccurately quantify the impacts on seagrass.Proposed dredging works are expected to impact upon water quality within the Study Area, as discussedin the WB EIS. As a result of shading and sediment deposition through elevated turbidity/suspendedsolids concentrations, this has potential to add to the direct impacts arising from the Project, which willinclude the removal of diversity from marine systems in the Study Area.The relative impact of different numbers of dredgers operating simultaneously has been demonstratedthrough the modelling of several different scenarios. The scenario predicted to have the largest impacton water quality in the region, is that which has both cutter suction and trailer suction dredgers operatingsimultaneously. This includes the trailer suction dredger bottom dumping adjacent to the reclamation sitewith rehandling via CSD, into the reclamation ponds and decant discharged from the reclamation ponds.For this situation, the EIS estimated that approximately 5,416 ha of benthic habitat outside the Projectfootprint has the potential to be impacted in terms of being touched by the dredge plume at some stageduring the dredging operations. This area includes potentially 1,406 ha of seagrass meadows (Table10-1). This estimated area was based on data assimilated from GHD studies with the long termmonitoring of seagrass meadows in Port Curtis and Rodds Bay that has been conducted by theQueensland Government Department of Employment, Economic Development and Innovation (DEEDI)since 2002 (program ongoing). Other monitoring programs have also been conducted in the Gladstonearea during this time, including the Port Curtis Integrated Monitoring Program (PCIMP) and activitiesconducted by the Centre for Environmental Management at the Central Queensland University. Datafrom these programs was also used to inform impact assessments conducted for the WB EIS.To estimate the area of seagrass that could be impacted by the dredge plume, the entire potential areaof seagrass habitat (as mapped between all surveys conducted by DEEDI) was calculated byassimilating across all areas where seagrasses have occurred across all surveys. This gave a potentialseagrass area (meadow + seed bank) within the Project footprint against which an assessment ofindirect impacts was made. This approach addresses the concern that seagrass meadows areephemeral and may not be present at any one survey location in any one year of survey (ergo notmapped) but may return to that surveyed habitat the following year. This approach also provides theability to include habitats that may support seagrass seed banks (and are, therefore, important seagrasshabitat) but not have seagrass actually present at the time of survey.During the monitoring program conducted by DEEDI, changes in species composition, biomass andspatial coverage of seagrasses have been measured in a subset of meadows from Port Curtis andRodds Bay. In December 2007 in conjunction with the PCIMP, data loggers were also added tomeadows of relevance to the long term monitoring program in Port Curtis to collect light, turbidity andtemperature data. This environmental data has been used to begin interpretation of how meadows may42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-80

e responding to changes in turbidity and the relationship between this variable and light availability andthe ‘health’ of the seagrass meadows. Given the limited availability of data collected to date, clearrelationships between these variables are not yet able to be determined (refer Chartrand et al. 2008,more recent monitoring data from 2009 and implications for correlative understanding betweenenvironmental variables not yet available). Further, trends that have been observed which indicate thatPort Curtis meadows may be limited by low light availability (Chartrand et al. 2008) have not been able todistinguish anthropogenic from natural variability in turbidity inputs and have not been able to ascertain athreshold of turbidity to which seagrasses in Port Curtis are resilient and beyond which recovery ofseagrass meadows following cessation of impact is possible.Given this lack of information about tolerance limits of seagrasses in Port Curtis to thresholds of turbidityloading, and distinction between impacts from anthropogenic or natural turbidity variability, it is currentlynot possible to provide accurate quantification of impacts on seagrasses that may be subject to reducedlight conditions and/or some sedimentation as a consequence of dredging activities. It is plausible thatthe seagrasses in Gladstone are resilient to some reductions in light and sedimentation as a result oftheir regular seasonal exposure to inputs of sediment associated with monsoonal rain events. However,the degree of resilience is not yet quantifiable and research and monitoring continuing under the PCIMPand DEEDI programs are working towards collection of data to improve the ability to address this.Accordingly, areas of potential direct and indirect impact were estimated based on the known area ofseagrasses from DEEDI and GHD surveys and predicted areas of plume dispersal based on modeloutputs. Table 10-1 outlines the areas of benthic habitat predicted to be directly and indirectly impactedas a result of this Project, and also highlights the area within the benthic habitat to be impacted that hasbeen known to support seagrass at any point during the 2002 – 2008 DEEDI seagrass mapping and asidentified in the GHD survey undertaken for this EIS. This totals approximately 6,318 ha of benthichabitat, including 1,664 ha of known seagrass habitat, which could be directly or indirectly impacted(even if the impact is momentary). In addition to expected permanent losses of high value ecologicalhabitats, temporary losses from indirect impacts related to reduced water quality from dredge plumefootprints are also expected. However, temporary losses would be expected to return to the Study Areaover time (within 2-5 years) following cessation of construction and dredging.While the area predicted to be impacted by the dredge plume in Table 10-1 from DEEDI and GHD data isquite large (5,416 ha total, 1,406 ha of seagrass), it should be noted that this is the maximum predictedplume area (measured as an exceedence of 5 mg/L above background ambient conditions), based on10 th percentile exceedences – i.e. this is the area that for no more than ten percent of the time may haveexperienced a plume > 5 mg/L above background conditions. While these exceedences could impactbenthic communities, such a small and infrequent increase in total suspended solids (TSS) is consideredunlikely to affect benthic communities under this spatial footprint. These assemblages would be adaptedto changes of this magnitude given they experience similar, and persist under similar, changes as aresult of seasonal variability in turbidity.More realistic estimates of potential indirect areas of impact that are considered of greater relevance forunderstanding potential impact to benthic communities are provided in Table 10-2. Site specific dredgeplume TSS objectives were calculated for areas containing sensitive receptors (refer to Section 9.1 fordetails). The lowest dredge plume objective presented is 29 mg/L TSS, an increase in TSS that couldcause shading affects on benthic communities. Under a realistic dredge scenario with a high rate of42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-81

sediment loading (Scenario 1B in Table 10-2), this increase in TSS is predicted to be exceeded for only10% of the time over an area of 311 ha, or 110ha for 50% of the time (Table 10-2 and Table 10-3). Thissuggests that while dredge plumes could extend over some hundreds of hectares, actual impacts tobenthic communities are likely to be realised over a much reduced area.Table 10-1 Areas of benthic habitat expected to be directly and indirectly impacted byconstruction and operation works (based on data from GHD and DEEDI)Location Expected Impact Habitat type Total BenthicArea (ha)KnownSeagrass Area(ha)*Reclamation area +bund wallDirect – habitat removal(not includingFisherman’s Landing)Intertidal andsubtidal softsubstrate235.9 221.6Channel to west ofreclamationIndirect – water qualityIntertidal softsubstrate8.7 3.4Western Basin residualarea (area to the northof the Western BasinReclamation Area)Indirect – water quality +habitat removalIntertidal andsubtidal softsubstrate299.1 274.6Channel to be dredged(all stages, alreadydredged)Direct – habitat removalSubtidal soft andhard substrates146.4 3.4Channel to be dredged(all stages, not alreadydredged)Direct – habitat removalSubtidal soft andhard substrates520.0 33.8All other areas withinGladstone Harbourpredicted as potentiallyimpacted by dredgeplume modellingPotential IndirectImpacts – water qualitySubtidal soft andhard substrates5,108.0 1,128.0Total Direct Impact 902 258.8Total Indirect Impact 5,416 1,406Total Potential Impact 6,318 1,665*Areas based on merged data from all DEEDI studies from 2002 to 2008 and GHD field survey data.There are a number of sensitive primary producer habitats (seagrass and algal beds) outside thedredging footprint under the plume that are likely to be indirectly impacted by the project (i.e. those within(greater than) the 30 mg/L contour lines on Figure 10-2 to Figure 10-5). These sensitive habitats,predicted to be in impacted areas, should be considered for targeting for research monitoring duringdredging. These habitats have been mapped by DEEDI in 2002 (Rasheed et al., 2003) and GHD in 2009demonstrating their persistence under existing dredging regimes but may be susceptible to chronicdredge related impacts. These habitats are located to the east of North Passage Island and to the eastand south of South Passage Island.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-82

This information is considered to the best available to hand to indicate what areas of habitat may beaffected by direct and indirect impacts from the Western Basin Project. Offsets are being negotiated byGPC with regard to permanent impacts and mitigation and management measures. This includesreactive dredge program management, aligned with water quality and seagrass monitoring programs,that were identified and promoted in the WB EIS (refer Chapter 9) to ameliorate and manage temporaryimpacts.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-83

302,500305,000307,500310,000312,500315,000317,500320,000322,500325,000327,500330,000332,500Based on or contains data provided by the State of Queensland (Department ofEnvironment and Resource Management) [2009]. In consideration of the Statepermitting use of this data you acknowledge and agree that the State gives nowarranty in relation to the data (including accuracy, reliability, completeness, currency or suitability) and accepts no liability (including withoutlimitation, liability in negligence) for any loss, damage or costs (includingconsequential damage) relating to any use of the data. Data must not be used fordirect marketing or be used in breach of the privacy laws.#*M7,375,000")R!.H!.HGraham CreekCURTIS ISLAND7,375,000The Narrows7,372,500Friend PointLaird Point7,372,5007,370,000!.H!.H!.H!.H")!.H, R7,370,0007,367,500Fisherman's Landing!.H!.H#*MFACINGISLAND7,367,5007,365,000#*MPORT CURTIS7,365,000RG TannaCoal Terminal7,362,500Barney PointCoal Terminal#*M7,362,500GLADSTONE7,360,0007,360,000")R302,500305,000307,500310,000312,500315,000317,500320,000322,500325,000327,500330,000332,5001:85,000 (at A3)0 0.5 1 1.5 2 2.5KilometresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of AustraliaGrid: Map Grid of Australia 1994, Zone 56oLegendIndicative Monitoring Location!. H - Habitat/Impact Monitoring#* M - Monitoring (Dredge Plume)") R - Possible Reference SiteWestern Basin Reclamation AreaFisherman's Landing Northern ExpansionExisting Channels, Swing Basins and BerthsProposed Dredge StageStage 1A - North China Bay LNGStage 1B - Fisherman's Landing LNGStage 2 - Laird Point LNGStage 3 - Fisherman's LandingStage 4 - Hamilton PointPort of GladstoneWestern Basin Supplementary EISIndicative Sensitive HabitatMonitoring Locations Figure 10-01G:\42\15386\GIS\WesternBasinSupplementaryEIS\Mxd\4215386-56_200.mxd Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.com© 2010. While GHD has taken care to ensure the accuracy of this product, GHD and DATA CUSTODIANS (GPC, DERM) make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.GHD and DATA CUSTODIANS cannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data Source: DERM - Aerial Photo (flown 2006); Gladstone Ports Corporation - Reclamation Areas, Dredge Footprint, Existing Channels, Port Limits; GHD - Sensitive Habitat Monitoring Location.Job NumberRevisionDate42-15386A14 April 2010

Table 10-2 Cumulative seagrass habitat (ha, as measured by DEEDI) predicted to be affected by differing plume concentrations underdredge Scenarios 1A, 1B, 2 and 3TSS PlumeConcentrationDredgescenario 1A10 th Percentile Exceedence 50 th Percentile ExceedenceDredgescenario 1BDredgescenario 2Dredgescenario 3Dredgescenario 1ADredgescenario 1BDredgescenario 2Dredgescenario 3>100 mg/L 5 6 5 0 0 0 0 0>90 mg/L 8 14 9 0 0 0 0 0>80 mg/L 18 32 21 0 0 0 0 0>70 mg/L 40 61 47 0 0 1 0 0>60 mg/L 69 101 81 0 2 3 0 0>50 mg/L 112 161 131 1 6 15 4 0>40 mg/L 170 230 201 4 26 36 24 0>30 mg/L 245 311 264 9 51 116 67 0>20 mg/L 321 519 431 24 164 267 187 3>10 mg/L 1240 1383 1332 49 468 631 635 1542/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-85

310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0007,380,000Scenario 1a at 10% Scenario 1a at 50%7,356,0007,356,0007,356,0007,356,0007,358,0007,358,0007,358,0007,358,0007,360,0007,360,0007,380,0007,360,0007,380,0007,360,0007,362,0007,362,0007,362,0007,362,0007,364,0007,364,0007,364,0007,364,0007,366,0007,366,0007,366,0007,366,0007,368,0007,368,0007,368,0007,368,0007,370,0007,370,0007,370,0007,370,0007,380,0007,372,0007,372,0007,372,0007,372,0007,374,0007,374,0007,374,0007,374,0007,376,0007,354,0007,376,0007,376,0007,376,0007,378,0007,378,0007,378,0007,378,000Based on or contains data provided by the State of Queensland . In consideration ofthe State permitting use of this data you acknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness, currency or suitability) andaccepts no liability (including without limitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data. Data must not be used for directmarketing or be used in breach of the privacy laws.7,354,0007,354,0007,354,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0001:120,000 (at A3) LEGENDo0 1 2 3 4 5KilometresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of AustraliaGrid: Map Grid of Australia 1994, Zone 56Seagrass Areas MergedProposed Dredge AreasFisherman's Landing Northern ExpansionWestern Basin Reclamation AreaTSS (mg/L)10-3030-5050-100Port of GladstoneWestern Basin Supplementary EISJob NumberRevisionDateSeagrass Areas Affected by>100 Scenario 1a Dredge PlumeFigure 10-0242-15386A14 April 2010G:\42\15386\GIS\WesternBasinAdditionalInfo\Mxd\4215386_005.mxd© 2010. While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd, DERM, DEEDI, WBM and GPC make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.comGGHD Pty Ltd, DERM, DEEDI, WBM and GPC cannot accept liability of anykind (whether in contract, tort or otherwise) for anyexpenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data source: Aerial Photo (flown 2007) - DERM; Seagrass Data - DEEDI; Plume Data - WBM; Dredge Channels - GPC.

310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0007,380,000Scenario 1b at 10% Scenario 1b at 50%7,356,0007,356,0007,356,0007,356,0007,358,0007,358,0007,358,0007,358,0007,360,0007,360,0007,360,0007,360,0007,362,0007,380,0007,362,0007,380,0007,362,0007,362,0007,364,0007,364,0007,364,0007,380,0007,364,0007,366,0007,366,0007,366,0007,366,0007,368,0007,368,0007,368,0007,368,0007,370,0007,370,0007,370,0007,370,0007,372,0007,372,0007,372,0007,372,0007,374,0007,374,0007,374,0007,374,0007,376,0007,376,0007,354,0007,376,0007,376,0007,378,0007,378,0007,378,0007,378,000Based on or contains data provided by the State of Queensland . In consideration ofthe State permitting use of this data you acknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness, currency or suitability) andaccepts no liability (including without limitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data. Data must not be used for directmarketing or be used in breach of the privacy laws.7,354,0007,354,0007,354,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0001:120,000 (at A3)0 1 2 3 4 5KilometresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of AustraliaGrid: Map Grid of Australia 1994, Zone 56oLEGENDSeagrass Areas MergedProposed Dredge AreasFisherman's Landing Northern ExpansionWestern Basin Reclamation AreaTSS (mg/L)10-3030-5050-100>100Port of GladstoneWestern Basin Supplementary EISSeagrass Areas Affected byScenario 1b Dredge PlumeJob NumberRevisionDateFigure 10-0342-15386A14 April 2010G:\42\15386\GIS\WesternBasinAdditionalInfo\Mxd\4215386_006.mxd© 2010. While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd, DERM, DEEDI, WBM and GPC make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.comGGHD Pty Ltd, DERM, DEEDI, WBM and GPC cannot accept liability of anykind (whether in contract, tort or otherwise) for anyexpenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data source: Aerial Photo (flown 2007) - DERM; Seagrass Data - DEEDI; Plume Data - WBM; Dredge Channels - GPC.

310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0007,380,000Scenario 2 at 10% Scenario 2 at 50%7,356,0007,356,0007,356,0007,356,0007,358,0007,358,0007,358,0007,358,0007,360,0007,360,0007,360,0007,360,0007,362,0007,380,0007,362,0007,380,0007,362,0007,362,0007,364,0007,364,0007,364,0007,380,0007,364,0007,366,0007,366,0007,366,0007,366,0007,368,0007,368,0007,368,0007,368,0007,370,0007,370,0007,370,0007,370,0007,372,0007,372,0007,372,0007,372,0007,374,0007,374,0007,374,0007,374,0007,376,0007,376,0007,354,0007,376,0007,376,0007,378,0007,378,0007,378,0007,378,000Based on or contains data provided by the State of Queensland . In consideration ofthe State permitting use of this data you acknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness, currency or suitability) andaccepts no liability (including without limitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data. Data must not be used for directmarketing or be used in breach of the privacy laws.7,354,0007,354,0007,354,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0001:120,000 (at A3)0 1 2 3 4 5KilometresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of AustraliaGrid: Map Grid of Australia 1994, Zone 56oLEGENDSeagrass Areas MergedProposed Dredge AreasFisherman's Landing Northern ExpansionWestern Basin Reclamation AreaTSS (mg/L)10-3030-5050-100>100Port of GladstoneWestern Basin Supplementary EISSeagrass Areas Affected byScenario 2 Dredge PlumeJob NumberRevisionDate42-15386A14 April 2010Figure 10-04G:\42\15386\GIS\WesternBasinAdditionalInfo\Mxd\4215386_007.mxd© 2010. While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd, DERM, DEEDI, WBM and GPC make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.comGGHD Pty Ltd, DERM, DEEDI, WBM and GPC cannot accept liability of anykind (whether in contract, tort or otherwise) for anyexpenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data source: Aerial Photo (flown 2007) - DERM; Seagrass Data - DEEDI; Plume Data - WBM; Dredge Channels - GPC.

310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000310,000312,000314,000316,000318,000320,000322,000324,000326,0007,380,0007,360,0007,360,0007,362,0007,362,0007,380,0007,362,0007,362,0007,364,0007,364,0007,364,0007,364,0007,366,0007,366,0007,366,0007,366,0007,368,0007,368,0007,368,0007,368,0007,370,0007,370,0007,370,0007,370,0007,372,0007,372,0007,372,0007,372,0007,374,0007,374,0007,374,0007,374,0007,376,0007,376,0007,376,0007,376,0007,378,0007,378,0007,378,0007,378,0007,380,0007,380,000Scenario 3 at 10% Scenario 3 at 50%7,360,000Based on or contains data provided by the State of Queensland . In consideration ofthe State permitting use of this data you acknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness, currency or suitability) andaccepts no liability (including without limitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data. Data must not be used for directmarketing or be used in breach of the privacy laws.7,360,0007,358,0007,358,0007,358,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,0007,358,000310,000312,000314,000316,000318,000320,000322,000324,000326,0001:100,000 (at A3)0 1 2 3 4 5KilometresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of AustraliaGrid: Map Grid of Australia 1994, Zone 56oLEGENDSeagrass Areas MergedProposed Dredge AreasFisherman's Landing Northern ExpansionWestern Basin Reclamation AreaTSS (mg/L)10-3030-5050-100>100Port of GladstoneWestern Basin Supplementary EISSeagrass Areas Affected byScenario 3 Dredge PlumeJob NumberRevisionDate42-15386A14 April 2010Figure 10-05G:\42\15386\GIS\WesternBasinAdditionalInfo\Mxd\4215386_008.mxd© 2010. While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd, DERM, DEEDI, WBM and GPC make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.comGGHD Pty Ltd, DERM, DEEDI, WBM and GPC cannot accept liability of anykind (whether in contract, tort or otherwise) for anyexpenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data source: Aerial Photo (flown 2007) - DERM; Seagrass Data - DEEDI; Plume Data - WBM; Dredge Channels - GPC.

10.1.2 Submission #3 and #11The level of uncertainty in predicted impacts to seagrass from the dredge plume warrants concern.Provide details on seagrass to be removed as a percentage of the same species found in the region.As noted above in response to Submission # 2, information provided in the WB EIS is considered to bethe best available to hand with regard to the ability to predict impacts to seagrass from dredge plumes. Itis acknowledged that additional data in regards to resilience of benthic ecological communities, includingall primary producer habitats, is needed to better understand local affects of dredging impacts. It isunderstood that monitoring programs being conducted by PCIMP and DEEDI are working towardscollection of this data with relevance to seagrasses, but understanding of algal and coral resilienceremains a data gap. Offsets in support of fisheries habitat are also likely to provide an avenue foradditional research to assist in addressing this knowledge gap. A water quality monitoring program and aseagrass health monitoring program were promoted in the WB EIS to assist in providing a reactivedredge management program to manage indirect impact potential given current lack of knowledge abouthow these systems may respond to indirect plume impacts. By actively collecting water quality andseagrass habitat health data during the dredge program, impacts to habitats will be able to be linked todegraded water quality associated with dredging works and management of dredging activities will beable to be managed to reduce impact. This may involve planned relocation of the dredger to rest thehabitat being affected or varying the dredger cycle.Management options regarding the reduction of water quality impacts from dredging works have beenfurther considered since publication of the WB EIS. These include reduction in the use of trailer suctionhopper dredgers and reduced need for rehandling of dredged material into the Reclamation Area.Accepted strategies identified within the WB EIS and discussed elsewhere in this document will beadopted forwards into a construction and dredge Environmental Management Plan (DMP). One of theseincludes the potential reduction or elimination of rehandling through utilisation of the existing offshorespoil ground. Monitoring programs should be used to enable reactive management of impactive activitiesuntil greater understanding of the influence of turbidity elevations on seagrass health can be determined.10.1.3 Submission #11Consider the potential impacts on seagrass for each of the 5 proposed locations and designs ofreclamation.A number of potential reclamation footprint configurations were qualitatively addressed in the earlyphases of the Project. A number of advantages and disadvantages to each configuration were comparedto assist in determining what the optimal configuration footprint should be to achieve all objectives of theProject, including minimal environmental impact. Accordingly, this comparison included whetherenvironmentally sensitive areas, including seagrass meadows, mangrove habitats or avifaunal habitat,would be impacted or lost under each option. The option selected and assessed under the EIS wasconsidered to be the most appropriate, because it had a reduced impact on seagrass colonies, thesensitive avifaunal habitats to the north of Fisherman’s Landing and provided a footprint that wouldreduce impact on creeks and water quality. As such, it is considered that the potential impact toseagrasses by each configuration option was addressed in selection of the design of the reclamation,and no amendment to the report is considered necessary.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-90

10.1.4 Submission #11Provide a description of which areas under each overlayed footprint outlined in figure 1.6 that aresensitive, with provision of hectare values on impacts for each of the 5 reclamation options.As indicated above in Section 10.1.3, the option selected and assessed under the WB EIS wasconsidered to be the most appropriate because it had a reduced impact on seagrass colonies, thesensitive avifaunal habitats to the north of Fisherman’s Landing and provided a footprint that wouldreduce impact on creeks and water quality. As such, it is considered that the potential impact toseagrasses by each configuration option was addressed in selection of the design of the reclamation,and no amendment to the report is considered necessary.10.1.5 Submission #11Revise the sentence that states that the removal of 11.2% of the Port’s seagrass is minimal due tocomparison with other seagrass in the entire Fitzroy region.A review of WB EIS documentation could not identify the specific sentence stating that “the removal of11.2% of the Port’s seagrass is minimal due to comparison with other seagrass in the entire Fitzroyregion”. The closest statement identified to this effect was that the loss of mapped seagrass by DEEDI“represents approximately 11.2% of seagrass within the port environment of the Fitzroy region andapproximately 2.6% of the seagrasses across all environments of the Fitzroy region (Ch 9 of the EIS).”This response explicitly quantifies loss as required by the Project Terms of Reference, whereidentification and reference to habitat loss is required at local and regional scales.At a local scale, large areas of seagrass meadows have been identified. The 2002 baseline survey ofPort Curtis and Rodds Bay identified 129 coastal and six deepwater seagrass meadows. Thesemeadows covered an area of 7,246 ± 421 ha and 6,332 ± 4,624 ha, respectively (Rasheed et al., 2003).The baseline survey was undertaken over a number of regions within Port Curtis and Rodds Bay,including:The Narrows;Grahams Creek;Fisherman’s Landing;Quoin Island;South Trees;Hummock Hill Island;Rodds Bay; andDeepwater areas.Table 10-3 provides, for each region, a summary of the areas (± reliability estimate) of seagrassidentified, and the distance of the region from the Project Area. Also provided in Table 10-3 are the areasof seagrass identified at a larger regional scale, including the distances of these seagrass habitats fromthe Project Area.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-91

Within 20 km of the Project Area 3,370.4 ± 197.8 ha of seagrass meadows were mapped. A further6,973.4 ± 4657 ha was mapped between 20 and 40 km from the Project Area, and 3,234.5 ± 189.4mapped between 40 and 65 km from the Project Area (Table 10-3; Rasheed et al., 2003). The ProjectArea is located within the Fitzroy Natural Resource Management (NRM) region of the Great Barrier ReefWorld Heritage Area (GBRWHA). The Fitzroy region contains one other substantial seagrass resource,the Shoalwater Bay area, which is located approximately 200 km to the north of the Project Area. To thesouth of the Project Area is the Burnett-Mary NRM region. A substantial seagrass resource is located atHervey Bay and Great Sandy Strait, which is located approximately 230 km to the south of the ProjectArea.As noted in Section 9.3.2 of the WB EIS, the Project will directly remove 11.2 % of the total seagrassarea identified in the 2002 DEEDI survey within the Gladstone region (Rasheed et al., 2003). As notedunder response to Submission #2 (refer above) comment regarding the area of seagrass habitat thatmay potentially be indirectly affected is difficult to quantify with the available data. The overall impactthese habitat losses may have on the biodiversity and prevalence of dependent communities has beenconsidered under the EIS and, for direct habitat losses, it is recognised that species currently using thesehabitats are likely to be displaced to other locations in the Gladstone/Port Curtis region.Table 10-3 Area of mapped seagrass and distance from Project AreaRegion*Mapped Seagrass Area(± R) (ha)Percent of area directlyimpacted by the Project< 20 km from Project Area < 20 kmThe Narrows 552.2 ± 77.6Graham Creek 28.7 ± 6Fisherman's Landing 1,359.2 ± 63.27.68 %Quoin Island 1,430.3 ± 5120-40 km from Project Area < 40 kmSouth Trees 641.4 ± 33.9Deepwater6,332 ± 4,6242.50 %40-65 km from Project Area < 65 kmHummock Hill Island 1,470 ± 95.4Rodds Bay1,764.5 ± 941.08 %* Rasheed et al. (2003); # Lee Long et al. (1997); ^ McKenzie et al. (2000).± R = Reliability Estimate.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-92

10.1.6 Submission #18Please re-categorise the 274.6 ha that makes up the balance of the bank to the north of thereclamation (Western Basin residual area) as a direct rather than indirect impact (i.e. total directimpact 533.4 ha)The classification of potential impacts of the Project into direct or indirect categories was based on theway the impact will be created, rather than the likelihood or longevity of the impact. Impacts classified asdirect are those that are a direct result of a Project activity (e.g. placing of the Reclamation Area willdirectly remove habitat). Impacts classified as indirect are those that are dependant on the action of theProject, in addition to some other physical or ecological process (e.g. the action of dredging will producea plume, which has the potential to interrupt physical properties such as light penetration, which canhave flow on effects to the marine communities).The availability of the Western Basin residual area as habitat for primary producers such as seagrass isnot expected to be lost permanently. Whilst the residual area may change in bank topography andhydrology, it is expected that the potential to support seagrass meadows will persist in this area. Thisregion has a history of seagrass persistence/recovery post changes in bank topography and hydrology,as is evidenced by the occurrence of seagrass meadows in Western Basin and Fisherman’s LandingBasin post construction of the existing Fisherman’s Landing infrastructure. Accordingly, re-categorisationof the area to the north of the Western Basin as a direct impact would be inconsistent.10.2 Marine Threatened Species10.2.1 Submission #4The EIS needs to more explicitly address the noise impacts of pile driving, and the evidence tosupport the proposed exclusion zones for pile driving, to avoid impacts on marine megafauna.It should be recognised that there is minimal pile driving associated with this Project. Pile driving is onlyrequired for the relocation of channel markers or beacons. Wharf construction is not involved in thisProject.In Australia, the Environment Protection and Biodiversity and Conservation Act 1999 sets two levels ofmitigation requirements for impulsive seismic signals, based one whether they will fall below or exceed160 dB re 1 μPa2.s Sound Exposure Level (SEL) for 95% of the time at 1 km range. This thresholdvalue is set as the EPBC Act considers it the threshold at which Temporary Threshold Shift (TTS) willoccur in marine mammals.An extensive discussion outlining the noise impacts of pile driving has been documented in Appendix Rof the WB EIS, pages to 63 to 67 and Appendix S pages 28 to 29. As identified in Chapter 9, page 103 ofthe WB EIS; underwater noise from pile-driving is expected to induce avoidance behaviour in marinemegafauna. Impact assessment for the project has determined that it is unlikely that this noise will have adirect physiological impact on marine megafauna if appropriate mitigation measures are employed.These measures include the use of warning noises, such as soft starts during pile driving, which providemegafauna an opportunity to relocate beyond an area about to be impacted by construction works,thereby reducing potential for impact. The administration of a “safety zone” will additionally be consideredto manage potential acoustic risk. This will be monitored by marine fauna observers.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-93

There are limited data on noise levels that cause TTS or Permanent Threshold Shift (PTS) in marinemammals (Richardson et al. 1995). For marine mammals, considered to have more sensitive hearingthan marine reptiles, the current TTS onset criteria (which are only vaguely defined and in considerabledispute) are for temporary threshold shifts to occur from impulsive signals at mean squared pressurelevels of 180 dB re 1 μPa or above. McCaughley and Salgado Kent (2008) suggest impacts would occurat < 50 m from a single pile strike.For marine mammals there may be some initial curiosity to pile driving noise. As the noise source isstationary, therefore not implying any collision threat and its poor overlap with their hearing thresholdcurves suggests that behavioural responses will be minimal, other than potentially maintaining acomfortable distance (perhaps several hundred meters) away. Since marine mammals are highly mobileand unlikely to linger near pile driving then calculations of the number of pile strikes required to reach anequivalent sound loading have not been considered.Odontocetes (toothed whales and dolphins) have very sensitive hearing which is centred at highfrequencies (10-100 kHz). National Marine Fisheries Service (NMFS (USA)) states that cetaceans shouldnot be exposed to underwater noise exceeding 180 dB re 1 μPa msp in order to avoid permanentphysiological damage to hearing. The underwater disturbance threshold for cetaceans is 160 dB re 1μPa msp for impulse noises and 120 dB re 1 μPa msp for non-impulse, continuous, industrial noises.These levels were set based on data on the effects of anthropomorphic noise on gray whale migration(from studies by Malme et al. 1984, as cited in NMFS 2006).An assessment of pylon driving noise in the Western Basin region was referenced a by a similar study inthe region (Wiggin’s Island). The assessment was based on piling activities using a 9t and 14t hammer(likely to be used in the Western Basin Project), assuming piling noise levels ranging from 197 dB (re 1µPa) up to 226 dB (re 1 µPa) at a distance of 1 m from the source. The underwater sound propagationused in the Western Basin for this assessment is consistent with the method commonly used in shallowwater less than 40 m deep (Urich 1983). The assessment determined an impact zone, which is an areawhere peak pressure levels from pile driving are predicted to be lower than the 218 dB (re 1 µPa (peak))threshold. The assessment (Connell Hatch, 2006), found that using a 14t hammer for pile driving, themaximum range for the impact zone is predicted to be less than 5 m.It is unlikely that dolphins or turtles will be exposed to pile driving sound intensities sufficient to cause anyserious physiological damage; marine mammals within 50 m of a single pile driving strike may receive asufficient sound intensity to cause temporary hearing loss; pile driving events will be audible in theWestern Basin for several kilometres up and downstream to animals with reasonable hearing capability.Pile driving impacts can be considered serious if the animals stray within 50 m of the impacting activities.Bartol et al. (1999) investigated the underwater hearing sensitivity of the loggerhead sea turtle usingauditory brainstem response (ABR) techniques. An audiogram of a species relates the absolutethreshold of hearing (in dB re 1 μPa) of that species to frequency. An animal is most sensitive to soundsat frequencies where its absolute threshold of hearing is lowest. Figure 10-6 depicts an underwateraudiogram of a loggerhead turtle indicating a range of effective hearing to be from at least 250 Hz to 750Hz with the lowest thresholds of about 80 dB.Essentially marine turtles have a substrate ear, likely a primitive sensor, i.e. pressure displaces the skull,the stapes move differentially to its inertia. Behavioural thresholds in one individual were observed at 4042/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-94

dB SPL. Unlike advanced reptiles, birds and mammals, turtles exhibit no natural startle response toaerial sound. If the same energy is delivered as vibration to the head or shell (via the substrate), animmediate startle response is observed. Essentially turtles hear by bone conduction, where sound isconducted to the inner ear by an osseous route, eventually vibrating the skull.Studies on juvenile loggerhead turtles have found the best hearing sensitivity was found in the lowfrequencyregion of 250-1,000 Hz. The decline in sensitivity was rapid after 1,000 Hz, and the mostsensitive threshold tested was at 250 Hz. Moein et al. (1995) investigated the use of pneumatic energysources (air guns) to repel juvenile loggerhead sea turtles from hopper dredges finding after threeseparate exposures to air guns, the turtles habituated to the stimuli.Figure 10-6 Underwater audiogram of the loggerhead turtle (Bartol et al 1999)A recent study undertaken by SVT (2009) in Cape Lambert, Western Australia, produced model outputsand impact zones from pile driving for turtle hearing based on 240 dB re 1 μPa for physical injury and120 dB re 1 μPa for behavioural and masking levels for adults and the 198 dB re 1 μPa2s for potentialphysical damage for turtle hatchlings. The study recognised that pile operations are discrete events andtherefore the zones identified are not continuous zones, but are an accumulation of all the piling eventsthat are to take place in the area. Each pile can therefore be separated into a circle of physical injury anda circle of avoidance. The circles of potential physical injury for adult and juvenile turtles in this instanceranges from 10 m for piling operations close to shore to 25 m for pile driving operations further offshore.Hatchling turtles are recognised as having sensitive hearing which declines in sensitivity as the turtle42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-95

matures. The circles of potential physical injury or hearing damage for hatchling turtles ranges from 400m for piling operations close to shore to 600 m for pile driving operations in deeper water (SVT 2009).Table 10-4 Predicted levels of impact from pile driving on marine speciesPossible Physical InjuryPossible AvoidanceEffect Marine Turtles Cetaceans andDugongMarine TurtlesCetaceans andDugongPeakPressureSoundExposureLevel222 dB re 1µPa 13 230 dB re 1µPa 20 175 dB re 1µPa 14 224 dB re 1µPa 21198 dB re 1µPa 15 198 dB re No Data Available 160 dB re 1µPa 231µPa 2. s 22 1µPa 2. s 22Source: BG Group, SVT (2010).The propagation of noise underwater is a factor of depth, sediment type, seabed contour etc. A recentmarine acoustic modelling study in the Western Basin region undertaken by the BG group (2010)suggested that minimum exclusion zones of 55 m for turtles and 22 m for cetaceans and dugongs beconsidered for pulse driving. Exclusion zones based on 160 dB re 1 μPa2.s should provide exclusionareas for consideration of, at a minimum, 160 m and 205 m for these species respectively (BG Group,2010; Table 10-4).Marine mammals and possibly marine turtles within 50 m of pile driving may receive a sufficient soundintensity to cause temporary hearing loss (McCaughley and Salgado Kent, 2008). If it is believed thatmarine mammals will frequent the area during operations then operations should be monitored bydedicated observers to determine if animals are within 300 m of the pile driving (a safety factor of six forTTS). It is recommended that monitoring should scan for marine megafauna at distances greater than300 m to identify when megafauna are approaching the 300 m safety zone to assist with management ofimpactive activities. Work should be suspended when marine fauna enter the 300 m safety zone of piledriving operations and scanning for fauna beyond this zone will enable reactive management to beundertaken within a timely manner to avoid injury if fauna enter the 300 m zone.As noted above, piling activity should be supported with marine species observers to maintain safedistances from impact. These have previously been determined by DEWHA to be between 300 m to 600m from seismic surveys, which is different from pile driving in spectrum and time. The underwaterdisturbance threshold for cetaceans is 160 dB re 1 μPa msp for impulse noises and 120 dB re 1 μPamsp for non-impulse, continuous, industrial noises is based on a seismic pulse made once every tenseconds.Studies (e.g. McCaughley and Salgado Kent, 2008) recommended that low-noise piling methods shouldbe adopted where feasible; avoid use of impactive (or impulsive) piling methods. Should impactive pilingmethods be unavoidable, a soft-start procedure should be implemented between long breaks in activity,where the piling energy is gradually increased over a 5-10 minute time period. This is expected to alertanimals to the presence of the piling activities and enable animals to move to a distance where the42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-96

likelihood of disturbance or discomfort is reduced. These measures conservatively manage for potentialacoustic impacts from pile driving to marine fauna and fall within the specified value outlined in EPBCPolicy Guidelines for seismic activity.10.2.2 Submission #4Address the potential impacts of the dredge vessel and associated artificial lighting on marinemegafaunaPotential adverse impacts on marine megafauna relating to increased lighting at the Project site,including habitat displacement or interruption to nesting success, were considered under the impact andrisk assessment to marine megafauna from construction of the Project. These were documented in detailin the Marine Megafauna Report (Appendix R of the WB EIS). Assessment determined that lightingimpacts are unlikely to be problematic as the turtle nesting habitat is sufficiently protected from lightpollution by the hilly topography that occurs on Curtis Island. Further mitigation measures were, however,identified in accordance with the precautionary principal of avoiding impact (provided in Chapter 9, pages121 to 123). These mitigation measures state that where possible, lighting solutions to reduce potentialattraction to the site should be implemented. This includes the use of low glare directional lighting, aimedtowards the project site, with sufficient shielding to further reduce stray light pollution. Marine faunacurrently coexist with extensive lighting of construction and operational sites within Gladstone and withcommercial fishing vessels in the Gladstone Harbour with no detrimental effects noted.All Project dredging will operate 24 hours a day, seven days a week until the required amount of materialis removed from the Project site. Typically, dredgers will operate 25-28 days per month. A keyenvironmental objective of the Project is to have potential impacts reduced to a minimum. For this tooccur, dredging needs to be undertaken constantly to ensure the shortest dredging campaign possible.This has implications for habitats and their resilience to impacts such that prolonged periods of increasedturbidity may lead to a decline in seagrass in the local area. Undertaking the Project dredging in thesmallest possible timeframe is the most viable option for this Project economically and environmentally.Given this, measures to reduce remaining impacts will include:Using a CSD (stationary) wherever possible/practical. CSDs can operate continuously;Use of a TSH dredger (slow-moving) outside of marine turtle nesting and hatchling periods (temporalmanagement) wherever possible. This dredger will also be fitted with a turtle deflector head; andUsing a backhoe dredger (land-based) when required.As the lighting used on board dredgers is for workplace safety and navigational requirements, thislighting can not be compromised for legislative reasons. In addition, the dredger will be operating in anenvironment that has extensive existing lighting from industry and the harbour. Lighting from dredgingoperations is not anticipated to significantly impact any marine threatened species. A key concern asnoted previously is nesting and hatchling turtles. These animals nest and will enter the waters on theeastern side of Curtis Island approximately 20 km (in a straight line) from the Project site. Thetopography of Curtis Island is comprised undulating terrain and it is transected by the Ramsay Rangeswhich maintains its highest peak of 173 m. This elevation prevents direct line of sight from the WesternBasin region and therefore preventing lighting impacts to turtle nesting sites from the Project site. Thedredging required for this Project is not anticipated to impact local marine fauna populations, however42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-97

measures to reduce potential lighting impacts from dredging and the Reclamation Area will include (asnoted on page 56, Appendix R of the WB EIS) where possible:Using senor or security lighting;Low pressure sodium bulbs;Yellow lighting in place of white lighting; andReducing the height of lighting wherever possible.These will be implemented in line with discussions with DERM.10.2.3 Submission #5The impacts of the project on seagrass meadows should be rigorously assessed. Rather thanconsider the losses in relation to the overall area of seagrass, the assessment should consider theimpact of the losses on Port Curtis seagrass communicates and their role in ecosystem function.The impacts of habitat loss and the resultant impacts to dependent species have been appropriatelyassessed in line with the Project Terms of Reference (ToR). Technical reports were provided in AppendixQ and R of the WB EIS. Appendix R specifically addressed the potential impact to marine threatenedspecies.10.2.4 Submission #11Discuss increased vessel traffic, and include "go slow zones" to reduce risk of boat strikes.Section 5.3.6 of Appendix R of the WB EIS, and Chapter 9 of the EIS, both discussed the risk to marinemegafauna from vessel traffic, including risk of boat strike. In Rodds Bay, areas used by dugongs,marine turtles and snubfin and humpback dolphins (i.e., Gladstone, creek mouths) overlap with areas ofhigh vessel traffic. High vessel traffic in shallow coastal areas has the potential to cause serious injuryand mortality to coastal dolphins, dugong and turtles (Greenland and Limpus 2006, Groom et al 2004,Wells and Scott 1997, ), reduce their access to particular areas within their home range (Allen and Read2000), affect their acoustic communication (Van Parijs and Corkeron 2001), and alter their behaviour(Lusseau 2003; Constantine et al. 2004). All of these effects can be potentially detrimental to all marinemegafauna species in coastal regions and particularly so for small populations with high site fidelity. Inthe past five years in Queensland, boat strike has been the leading cause of mortality in turtles anddugong (Greenland and Limpus, 2004).For most of the Queensland coast, areas used by dugongs, marine turtles and snubfin and humpbackdolphins (i.e., marinas, shallow bays, and creek mouths) overlap with areas of high vessel traffic. Thismay lead to conflict and potential impacts that can be determined as direct or indirect on marine species.An evaluation to determine the risk of these impacts occurring requires the consideration of severalparameters:Vessel strike;Interrupted communication of marine animals; andHabitat displacement from increased noise and presence.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-98

The degree to which these impacts are likely to occur is determined by several environmental andvessel-related factors such as:Vessel size (draft and mass);Vessel speed;Average number of vessels transiting; Bathymetry of the area (Hodgson 2004);Available habitat;Substrate (Ainslie 2003); andPopulation density of marine fauna.The majority of information relating to vessel strikes and marine fauna in Australia and abroad implicatessmaller recreational and commercial watercraft as the major causative agent of fatal and near-fatalvessel strikes (Ross 2006). The overwhelming trend encountered in a review of literature from Australiaand abroad is that negative interactions between marine fauna (dugongs, marine turtles, cetaceans) andvessels increases substantially with vessel speed and occurrence (Hodgson and Marsh 2007; Sorice etal. 2007; Groom et al. 2004, Ng and Leung 2003).When breathing or basking at the surface and/or when foraging in shallow water environments, turtlesare most vulnerable. Cetaceans are generally capable of avoiding collisions with vessels. Small inshorespecies are more susceptible to small to medium sized recreational and commercial crafts such as jetskis, launches and ferries (Ross 2006). Indo-Pacific humpback dolphins (Sousa chinensis) in Hong Kongwere found to derive little stress from slow-moving vessels, however fast-moving vessels disruptednormal social behaviours (Ng and Leung 2003).Some species of whale appear more susceptible to ship-strikes (fin whale Balaenoptera physalus; NorthAtlantic right whale Eubalaena glacialis) than other species such as the blue whale (Megapteramusculus) (Douglas et al. 2008). Vessel strikes on humpback whales (Megaptera novaehollandiae) aregenerally associated with commercial whale watching vessels, and although this species is known to beoccasionally involved in negative interactions with ships, a study from the eastern Pacific region indicatedthat the frequency was very low (Douglas et al. 2008). A total of 14 vessel strikes (type of vessel notspecified) on cetaceans have been recorded between 2003 and 2007 according to the EPA’s MarineWildlife Stranding and Mortality Database Annual Report (2007).Literature suggests the highest vessel-related risk to marine fauna are from fast moving vessels inshallow water, where time to undertake evasive action and find refuge at depth are greatly compromised(Hodgson 2004, Groom et al 2004, Hazel 2007). These factors may ultimately provide circumstance for acollision or given high frequency over time may sustain the displacement of species from habitat.The species observed on the marine fauna survey (mainly dugong and turtles) in the proposed Projectfootprint were found to be of a higher density compared to the surrounding waters at a high tide. Thissuggests that the activity associated with dredging in the area will displace numerous species. However,given the parameters of the vessels involved the Project boat strike is highly unlikely.An increased level of vessel traffic, including shipping as result of the dredging may increase thelikelihood of regular disturbance to foraging marine megafauna potentially leading to local displacement.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-99

Disturbance of benthic marine habitats through either propeller wash of the seabed or anchorage mayalso reduce or damage available habitat.Disturbance from boat traffic may have indirect impacts on dugong populations through disruptions infeeding, which has been shown to occur even when boats are passing at distances greater than 500 mfrom the animals (Hodgson and Marsh 2007). Where dugongs are feeding on large seagrass beds andare disrupted by a single boat passing, they tend to move in response to boats and resume feeding afterapproximately 2 min (Hodgson and Marsh 2007). However, dugongs and marine turtles that are feedingon small seagrass patches and are being continually disturbed by boats could either (a) havesignificantly reduced time available for feeding, which represents a reduction in habitat quality, or (b)could be displaced from an important feeding area, which effectively reduces the area of habitat availableto a dugong population. The above-mentioned impacts from vessel traffic are unlikely to occur as part ofthe Project construction. The speeds of construction vessels associated with the Project are slow-movingdredgers, and in some instances will be stationary within the Project footprint. The risks identified aboveare of particular relevance to fast-moving vessels such as pilot boats or large power boats that currentlyexist within Gladstone Harbour; this is acknowledged and provided for context as a concern for thesespecies.The parameters of dredging vessels provide time for species that may be encountered in the port andtherefore substantially reduce the likelihood of negative interactions between vessels and marinespecies. Due to the low speed at which they will be operating, manoeuvrability of vessels is limitedsubstantially. This affords animals potentially in the path of approaching vessels to move without risk of adirection change placing further stress on the animals.The slow speed of vessels affords animals potentially in the path of approaching vessels sufficient timeto move without the need of a direction change which can place stress on the animals. As these vesselsare restricted by speed, they are therefore unlikely to pose a high risk.Voluntary transit lanes and speed limits set in other areas along the Queensland coast for protection ofdugongs and marine turtles have low levels of compliance (Groom 2003; Hodgson and Marsh 2007). Asa precautionary measure, the EIS therefore, recommended that enforced vessel lanes with speedrestrictions should be designated for both construction and operational phases of the Project to protectmarine megafauna species from vessel strike or disturbance. It was also recommended that theconstruction workforce should be provided with information in regard to the risks to marine megafaunafrom vessel strike and notified of the requirement to avoid interaction with those species.10.2.5 Submission #11Discuss how the boat surveys at one per month, in conjunction with 6 days of aerial surveysconducted over a 3 month period might underestimate the number of megafauna utilising the area.The Marine Megafauna Baseline Assessment was designed to investigate megafauna habitat utilisationin the Port Curtis region and was not designed to be, or promoted as, a population abundance estimateof marine megafauna species in the region. Longer term studies designed for the task of megafaunapopulation estimates would need to be conducted to achieve this goal. This was not within the scope ofthis Project or defined within the Project’s ToR. Such long-term surveys have been undertaken byProfessor Helene Marsh and her research group from James Cook University, which have included42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-100

systematic aerial surveys of the GBRWHA approximately every five years between 1986 and 2005 byflying transects across the depth gradient (Marsh and Saalfeld, 1989; Marsh et al., 1996; Marsh andLawler, 2001, 2002).Grech and Marsh (2007) use the composite, spatial information on dugong distribution and relativeabundance from these surveys to develop a spatially explicit dugong population model. By using the timeseries of data collected over 19 years, the model (which was reported in the Marine Megafauna BaselineReport for the EIS, refer Appendix R) accounts for temporal changes in the use of various regions bydugongs including movements resulting from events such as seagrass dieback (Marsh and Kwan, inpress).Grech and Marsh’s (2007) model maps the relative density of dugongs across the GBRWHA at the scaleof 4 km 2 dugong management units (cells), the spatial scale recommended for managers under CriterionB of the International Union for Conservation of Nature and Natural Resources Red List (www.IUCN.org2009). This approach makes the assumption that the model of dugong density developed from the timeseries of aerial surveys is a robust index of a region’s conservation value for dugongs. The habitatutilisation data has been given context within this model as the same aerial survey transects were flowna total of six times over a nine month period where Marsh’s robust model is based on five survey eventsover almost 20 years. Project surveys were flown with the intent of “value-adding” to existing distributionand habitat use data.The aerial surveys conducted for the Project were flown at high and low tides to detect movement ofspecies that would be considered to have increased access to resources at a high tide. This isconsidered an important aspect of the Project as habitat reduction and increased vessel activity willoccur as consequence to this development. This survey technique successfully recorded an increase inhabitat use by dugong and turtle species at high tide. This distribution was compared with Marsh andGrech’s model to indicate that areas of the port region changed to high value habitat for dugong specieson a high tide.The application of this model is justified because:(1) Specialised areas of high conservation value such as calving or mating areas and migratory corridorshave not been identified; and(2) Density estimates are regarded as robust surrogates of habitat utilisation (Hooker and Gerber, 2004),fulfilling the objective of the survey.Additionally, boat-based surveys were undertaken to provide an indication of habitat use at a smallerscale compared to the regional extent of the aerial surveys. This also allowed for identification ofobserved animals to species level. The surveys and subsequent reporting highlight the importance of thisarea to marine megafauna species.10.2.6 Submission #11Use soft-start during piling to mitigate vibration. Undertake during low tide.As mentioned in Section 10.2.1, it should be recognised that there is minimal pile driving associated withthis Project. Pile driving is only required for the relocation of channel markers or beacons, and wharfconstruction is not involved in this Project.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-101

The use of soft-start piling strategies to mitigate against impacts to marine fauna was noted in the WBEIS in Chapter 9 and Appendices Q and R. This mitigation measure would require the contractor to usesoft-start procedures where the hammer is not used at full strength at the start of a pile driving session.Furthermore, whilst being inefficient for construction, there would likely be little impact to constructionwith this techniques an alternate mitigation measure. It is unlikely to be feasible to only undertake pilingduring low tide, and risk impact assessments completed for the WB EIS did not determine that thismitigation measure was required.10.2.7 Submission #12Update Figure 9.11 to include data based on WWF research (Nias et.al 2009) - snubfin andhumpback dolphins.After an extensive desktop search including the WWF web portal (and direct request from WWF staff lateJanuary/early Feb 2010), ScienceDirect literature database, and other scientific publication databases,the suggested reference by Nias et al. 2009 was unable to be found. A summary document “ConservingAustralia’s Unique Coastal Dolphins” was found on the WWF website which did not include any dolphindistribution mapping. The figure in the EIS document is from Dr. Parra’s research which is in the publicdomain in a peer–reviewed publication and suggests that the northern coastline of Australia is likely tosupport both (Sousa and Orcaella) dolphin species, although in some locations this is unconfirmed. Thefigure in the report identifies the entire Queensland coast as known habitat for both species, which is ofgreatest relevance to this report in understanding what potential impacts to habitats available to thesespecies may occur as a consequence of this Project. Accordingly, the report has not been updated asthe submission suggests as it is assumed both species inhabit the Gladstone coastal region.10.2.8 Submission #12Enhance text regarding habitat requirements and ecological niche of dolphins; acknowledge impactof harbour expansion and dredging on dugong and dolphin numbers and further impact due tohabitat loss.Appendix R “Marine Megafauna Baseline Assessment” of the WB EIS provides a comprehensive reportthat outlines the ecological niches and species observed on survey. The literature review provides acontext to species observed on survey and significantly adds value to local data of the region. A RiskAssessment of potential project impacts is provided in Chapter 7 of this document. The Project hasconsidered the impacts that may occur to dolphin and other megafauna from the Project activities,including the undertaking of capital dredging and the building of a bund wall. This is not referred to as aharbour expansion, but establishment of a Reclamation Area. The Marine Megafauna BaselineAssessment does consider the future proposed uses of this region in Chapter 8 in Cumulative Impactsand Mitigation Strategies.The large spatial scale surveyed under the Project identified areas within the Survey Area that are ofhigh value to dugong and marine turtles, with numerous animals identified in the southern part of PortCurtis (Tannum Sands) associated with known seagrass habitats. The dugong spatial model applied tothe Project aerial survey data highlights the importance of three core regions in the Survey Area at hightide.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-102

Of notable importance to this Project is the value of habitat detected in the immediate Project footprint.The Rodds Bay DPA is approximately 515 km 2 in area, of which a minimum of 3 km 2 of known seagrasshabitat will be directly reclaimed and or removed by the proposed Fisherman’s Landing and WesternBasin reclamation Projects. Further indirect impacts to surrounding habitats are possible. Given themodel output, this loss of habitat will impact and displace species within this core area. The finer spatialscale survey identified use of habitat within the Project footprint by Indo-Pacific humpback dolphins,dugong and green turtles. It is expected that these key marine fauna species have a higher presence inareas of important habitat i.e. in close proximity to the port and channels, creek and river mouths andseagrass meadows, though the requirement to transit between habitat patches needs to also beacknowledged. The marine megafauna survey supported a number of key findings:Dugong distribution recorded on survey supports previous aerial survey observations by Marsh et al.2005 and a close association with seagrass habitats.The habitat utilisation by dugongs was notably different at a high tide compared with low tidedistributions, suggesting the importance of inter tidal seagrass habitats to dugongs in this area.Marine megafauna species are widely distributed throughout Port Curtis and the Gladstone regionwith observed high habitat utilisation, recognising the importance of Rodds Bay DPA habitat area forthese coastal species, particularly on a high tide;The environment of Western Basin and adjacent waters represent important habitat for Indo-Pacifichumpback dolphins of various age classes as numerous calves were observed on survey;Nesting habitats for marine turtles do not occur within the immediate footprint of the Project thoughinter-nesting habitat is identified within the Project Area; andGood quality foraging habitats exist for green turtles and habitat of high conservation value todugongs is recognised throughout much of the Project Area and Port Curtis.Given that the Western Basin Dredging and Disposal Project involves the construction of a reclamationsite over existing seagrass habitat within Western Basin, the marine environment at this local scale willbe markedly disturbed. It is believed that the WB EIS and the appendices associated with the main EISreport do adequately provide detailed information regarding the potential impacts to marine megafaunawithin the Gladstone region, and include mitigation measures associated with ameliorating identifiedimpacts. The reports have not been altered.10.2.9 Submission #19An unacceptable risk for the dugong and snubfin dolphin population and susceptible to localextinction.The Marine Megafauna Baseline Assessment of the WB EIS (Appendix R) suggests that the areaproposed for development is of importance to numerous marine threatened species, including dolphinand dugong. The proposed Project entails reclamation and extensive dredging which is consideredunlikely to lead to local extinction of these species as there are adjacent habitats that are demonstratedto support these species that will remain unaffected. However, research on subpopulations in this regionhas not been undertaken and carrying capacity of adjacent habitats is unknown. The report notes thatcumulative impacts anticipated for this region from proposed developments (facilitated by this Project)42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-103

warrant further consideration of a strategic assessment of development and environmental impactsincorporating better understanding of seagrass assemblage resilience to these types of projects, as willbe developed through the proposed DEEDI and PCIMP monitoring programs (refer also to the responsein Sections 10.1.1 and 10.1.2 for detail).10.2.10 Submission #11Increase in noise during and following completion will increase noise stressors to megafauna.Undertake monitoring to determine changes in habitats and abundanceMarine megafauna currently co-exist within the Project area, adjacent to the Fisherman’s Landingreclamation, with commercial and other shipping traffic. It is not expected that increased noisedisturbance of this area as a consequence of increased vessel traffic during the operation of the facilitywill result in displacement of marine megafauna. Noise impacts from construction and operation of theProject on marine megafauna were assessed in detail under Chapter 9 of the WB EIS and withinAppendix R. The underwater noise from dredging during construction works is likely to induce avoidancebehaviour in marine megafauna. Other construction activities that will produce underwater noise includethe placement of rocks during the construction of the bund, and pile driving for the required channelmarkers. It is unlikely that this noise will have any direct physiological impact on marine megafauna ifappropriate mitigation measures are employed. These measures include the use of warning noises, suchas soft starts during pile driving, which provide megafauna an opportunity to relocate beyond an areaabout to be impacted by construction works, thereby reducing chance of impact. As with the underwaternoise from dredging, it is likely that this noise will induce short term avoidance behaviour in the localmegafauna, however, return to the affected area may occur following cessation of the impact ifappropriate habitat is available.10.2.11 Submission #16Concern that dredging of ASS is understated. Particular reference is made to anecdotal evidence ofulcerated crab shells. A request is made for assessment of crab and fish stocks in consultation withthe commercial fishing fleet.Anecdotal evidence from the fishing community suggests that acid sulfate soils (ASS) have led toulcerated crab shells. However, ulceration of crab shells typically occurs from disease. Desktop reviewsuggests that ASS may result in stress for crabs which could lead to greater susceptibility for diseaseincursion. Any direct causal relationship between ASS and ulceration is currently not well understood.10.3 Cumulative Impacts10.3.1 Submission #7Consider the environmental impacts of the dredging component of the Wiggins Island Coal Terminalwhen assessing cumulative impacts for Western Basin dredging.Submission 7 noted that the impacts from the Wiggins Island Coal Terminal (WICT) were considered tobe in place as part of the base case assessed for the Western Basin Dredging and Disposal Project. Inthat context, the cumulative impact assessments conducted for the Western Basin Project were42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-104

conducted from the base case condition, which took into account the WICT impacts. Accordingly, theseimpacts have been intrinsically considered as part of the cumulative impact assessment and additionalinclusion would effectively double up on these impacts. In the WB EIS, the cumulative impacts of multipledredging and reclamation projects on water quality are discussed in Chapter 7 (Coastal Management),with cumulative impacts to benthic communities also addressed in Section 9.3.4 (Marine Flora andFauna). Cumulative impacts are further considered in Chapter 18 (Sustainable Development).10.3.2 Submission #8Option 2A requires a shorter trestle than Option 1B therefore lesser impacts from pile driving andavoids disturbance of Curtis Island mangroves.There are a number of apparent benefits associated with APLNG’s Option 2A in comparison to Option1B, one of which is the shorter trestle length. The reduction in pile driving is noted, as is the removal of apotential constriction to boating access between Curtis Island and North Passage Island.10.3.3 Submission #11Clarify extent to which areas adjacent to the development will be restricted for recreational andprofessional fishing.The footprint of the reclamation will be permanently lost to fishing, and it is expected a buffer of exclusionaround those construction works will also be required for safety. However, exclusion zones will belimited, and are to be defined through proponent EIS studies. Plan 906-0049 Proposed MaritimeExclusion Zones (Figure 15-1) provides details of exclusion zones adjacent to the proposed reclamation.It should be noted that exclusion zones associated with the various wharf jetties from the proposedreclamation will also apply.Dredging works will likely operate under similar conditions to existing commercial vessel traffic.Recreational and commercial fishing vessels would likely have to give way to trailer suction hopperdredgers and avoid stationary cutter suction or backhoe dredgers.Construction works will require a construction and dredge management plan with a scheduled programof dredging and construction works which will be subject to discussions and agreement with the RegionalHarbour Master for vessel traffic safe operation.10.3.4 Submission #11Change in stormwater flow could increase erosion to mangrove habitats and increase in groundwater levels could expose vegetation to excess salt in old marine exposed soils. Please includemonitoring in EMP.Monitoring of mangrove health for detrimental change is identified for inclusion in the EMP, as identifiedin the WB EIS (Chapter 19, Figure 19.12). Groundwater level monitoring can also be included as apotential predictive indicator for any related impacts. Stormwater flows (via creeks) currently discharge tothe harbour, and will continue to do so. Groundwater levels will only be substantially different in thereclamation itself.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-105

10.3.5 Submission #19The submission notes the EIS does not address (include) the scale of the project (LNG industry),potential impact on marine environment and the piecemeal and inadequate environmental impactprocess and poor quality assessment documentation of the whole industrial development.The scope of works, as defined by the ToR for this Project, was designed to look at the impact of theWestern Basin Dredging and Disposal Project, including all potential channel dredging for the Gladstoneport within the foreseeable future. Effectively, all proposed LNG plants and port facilities will requiredredging of new channels, as defined in the WB EIS project description (refer Chapter 1), with disposalof dredged material proposed for the Western Basin reclamation. Rather than consider these dredgingworks in isolation, the potential cumulative impact associated with the proposed dredging program (whichmay involve multiple dredgers operating simultaneously) has been considered under the WB EIS byincluding all envisaged future dredging works in the WB EIS.Assessment of impacts associated with development of facilities on Curtis Island or elsewhere in theGladstone area that is not associated with the Western Basin reclamation, including the construction ofLNG facilities, is however outside the scope of reference for this Project. As such, works proposed forFisherman’s Landing, LNG Limited and Wiggins Island Coal Terminal have not been included in theimpact assessment for this Project. Wiggins Island Coal Terminal has already achieved approval and thedredging works to be undertaken for Fisherman’s Landing and LNG Limited are being assessed underseparate approvals processes. Inclusion of those impacts in this Project would duplicate effort.In accordance with the ToR, cumulative impacts associated with the construction and operation of landbased works (i.e. beyond the proposed dredging works), have not been addressed under this Project.Full impact assessments to support any such future developments will be required to be completed foreach of those projects as they are realised. However, it was appropriate to explore potential cumulativeimpacts that may result from concurrent marine construction activities within the Study Area as thesecould compound and amplify the impacts identified by this Project. As such, potential impacts, as knownin concept only, of potential future developments within Port Curtis/Gladstone region were consideredunder a cumulative impacts assessment. It was noted that permanent habitat losses from any futuredevelopments would need to offset such losses in accordance with the EPBC Act and QueenslandGovernment’s Environmental Offset Policy. It was also noted that any future constructions would need toconsider the principals of, and be in accordance with, the Queensland Government Fish HabitatGuidelines (FHG 006).Assessment of impacts associated with future developments will be needed against a terms of referenceof relevance to each project once those developments are seeking approvals to proceed.10.4 Migratory Birds10.4.1 Submission #11 and #12 Project site is within a wetland of national significance and adjacent to Narrows – of importance formigratory avifauna (CAMBA, JAMBA sites). Recommend provide detailed evaluation of thesewetlands for avifauna against criteria for Directory of Important Wetlands, and JAMBA/CAMBAtreaties.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-106

Delete the statement assuming that the Gladstone region does not support significant numbers ofmigratory shorebirds. Refer to CCC supporting document, Briggs 2009.The value of the study area for migratory birds is discussed in Section 9.2.2 of the WB EIS chapter andin Section 3.4.6 of Appendix P the Terrestrial Ecology Technical Report. Existing DEWHA mapping doesnot formally recognise the Gladstone region as an internationally or nationally important wetland formigratory birds through the mechanism of a RAMSAR or DEWHA site, which forms the basis of thecomment.Additional data provided through Submission #12 does, however, suggest that the region may qualify asinternationally significant, given that there are at least three species that have been recorded in numbersthat exceed 1% of the population, regularly, since 1996. This dataset referenced in support of thisinformation is not, however, publicly available and was, therefore, not included in the impact assessmentand reporting for the Project at the time of the WB EIS delivery.With the acknowledgement of this dataset, the Gladstone region may have a greater importance formigratory shorebirds than that recognised by regulatory agency mapping and data records. However, todate no formal submission for listing has been put forward and, as such, the description of the relativeimportance of the habitats provided in the WB EIS is in accordance with that provided under legislation.10.4.2 Submission #11 and #12Identify that migratory birds will be exposed to noise >30db while feeding on exposed tidal flats withinthe EIS and provide a list of mitigation measures, including avoiding noisy activity during low tide.Submission comments on the susceptibility of shorebirds to ‘visual disturbance caused by themovement of plant, people and vehicles’ as well as noise and vibration disturbance, identifying asound/visual barrier (at least 5 m high) as a control strategy to buffer wildlife.The Project is situated adjacent to existing reclamation, construction and other industrial activities. Fieldsurveys indicated an existing migratory bird population that persists under these conditions. Speciesidentified during field surveys and desktop assessments were documented in Appendix P of the WB EIS.It is acknowledged that the Project is of a larger scale than surrounding construction, and that theconstruction of the bund wall has the potential to induce a noise, vibration and visual disturbance toshorebird species, which can be sensitive to these disturbances.Given the current population’s resilience to similar disturbances from other projects in the area, andexamples of shorebird adaptations to disturbances of similar activities in other areas of Queensland (Portof Brisbane reclamation area), it is suggested that the populations have the potential to persist throughthe construction of the Project irrespective of the level of noise they may be exposed to.Successful use of sound and visual barriers to mitigate impacts to avifauna species is not welldocumented, however in theory, they may act as a control strategy. It is also unknown what level ofdisturbance would occur as a result of construction of such a barrier and removal of the barrier oncedredging and reclamation works have ceased. Impacts from sound and lighting on avifaunal populationswere addressed under the WB EIS risk impact assessment and this control measure was not deemedrequired. It is expected that avifaunal communities in this area are likely resilient to an impact of thisnature given their persistence under previous dredging and reclamation works.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-107

10.4.3 Submission #12Submission challenges the value of the proposed retention pond as habitat for migratory shorebirdsidentifying that ‘to suggest man made habitat can replace the intertidal mudflats that will be destroyedby this development is misleading’.The report (Appendix P of the WB EIS - Terrestrial Ecology Technical Report) describes the retentionpond purpose for the management of the quality and discharge of tailwater and stormwater, with apotential to provide habitat for migratory shorebird and tern species. The discussion also clarifies that thispotential and value would be environmental dependant on conditions. The report does not propose thisarea as a replacement habitat, but recognises that avifauna may choose to use this habitat as they havedone in other locations where retention ponds have been created. Opportunistic records at the nearbyFisherman’s Landing reclamation ponds identified a number of shorebird species using these habitats,and use of areas similar to these has also been noted at the Port of Brisbane reclamation ponds.10.4.4 Submission #12 Threatened birds, e.g. Eastern Curlew, refer to CCC support document, Briggs 2009.Targeted avifauna surveys were undertaken in June 2009 as part of the Project. Seventy-seven birdspecies were recorded from the Study Area and adjacent habitat during surveys, the vast majority ofwhich were forest/woodland-dependent species recorded from the woodland habitat in the west of thestudy area. As reported in Appendix P of the WB EIS, bird species recorded during surveys utilisedhabitat within the Study Area mainly for foraging and/or roosting. The areas targeted for reclamationactivities and dredging works under this Project did not support any roosting birds but were seen to beused for feeding. The likely impacts from this Project are therefore related to reduction of suitable feedinghabitat. Significant areas of available feeding habitat will continue to be available to roosting birdsfollowing this Project, and direct or indirect impacts to avifauna are not anticipated from this Project.Additional information regarding this is provided in Appendix P of the WB EIS.10.5 Mitigation of Impacts and Habitat Offsets10.5.1 Submission #11Section 9.4.5 of the EIS describes that there will be impacts from the development to marine speciesand biodiversity. Please provide more detail regarding mitigation of impacts - loss of habitat, foodresource, local species etc.An overall loss of benthic habitat and indirect impacts to species assemblages are expected from thisProject from dredging and reclamation works. Marine habitats, and the communities they support, thatwill be affected by the project were described in detail under Appendices Q and R of the WB EIS, theproposed mitigation measures for these impacts are also outlined in these documents. Impacts to thesehabitats were also described in Appendices Q and R and under Section 9 of the WB EIS. Permanentimpacts on the marine ecological values of the area include the permanent direct removal of an area(approximately 275 ha) of intertidal and subtidal habitat within the Western Basin Reclamation Area. Anadditional 9 ha of benthic habitat within the channel to the west of the reclamation is also likely to bepermanently changed. The entire 284 ha area supports known seagrass habitats of demonstratedimportance to dugong, marine turtles and of indirect importance to coastal dolphin species. In addition, a42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-108

ange of temporary impacts are expected as a result of construction activities, including dredge plumeimpacts and noise impacts.Where a direct loss of habitat occurs, compensation will be provided through application of the offsetspolicy.There is expected to be an immediate reduction in biodiversity from dredging works, however theimpacts are likely to be temporary with assemblages recolonising dredged areas over time. Permanentloss of habitat under the Reclamation Area will need to be offset. An offsets package of relevance to allGPC activities is currently being negotiated by with regulatory agencies (refer to Section 12).Alternation of soft sediment environments under the reclamation wall into intertidal hard substrateenvironments will provide three dimensional habitat, both intertidally and subtidally, which may promotespecies settlement and will provide additional habitat niches than currently exist. Three dimensionalhabitats, such as rock revetment walls, are also preferred structures compared to two or one dimensionalstructures in regards to fishery values, as three dimensional structures provide a greater colonisationarea for juvenile fish and crab taxa, increasing available niche refuges. Use of rock revetments forreclamation works are, therefore, in accordance with the principles of the Queensland Government FishHabitat Guidelines (FHG 006). This creation of interstitial habitat may partially offset some of the habitatlosses associated with direct removal as these areas will be rapidly colonised and may support a greaterdiversity of species than currently persist intertidally. Rock revetment walls are also known to supportalgal assemblages, which may offset some direct losses of benthic primary producer (seagrass) habitat.Additional mitigation measures against potential impacts identified in the EIS include marine faunaobservers, “go-slow” areas for boating, reductions in lighting impacts, and the use of warning noises,such as soft starts during pile driving, which provide megafauna an opportunity to relocate beyond anarea about to be impacted by construction works, thereby reducing chance of impact (see Appendix R ofthe WB EIS for further details on mitigation and management measures).Monitoring of water quality and sensitive benthic habitats (as discussed under response to Submissions#2 and #3 above) should also be undertaken to detect any possible declines in water quality and toenable reactive dredge management to occur to mitigate against habitat impacts and flow on affects todependent species. A dredge and construction Environmental Management Plan (DMP) will bedeveloped for the Project. It is expected this document will include conditions for environmentalmonitoring and impact mitigation as identified in the WB EIS.10.5.2 Submission #11 Identify disturbance to migratory shorebirds during feeding periods as an issue, and providemitigation measures.As identified in Chapter 9, Section 9.2.3, impacts from construction activities are expected. It isrecognised that these disturbances can have a significant impact on migratory bird species if they restrictaccess to a limited resource or inhibit wildlife behaviours during a critical phase of the animals’ life-cycle.Although migratory species may be present throughout the year, greater numbers are expected to visitthe area during spring and summer, when an impact would have its greatest effect on this group. Risk ofimpact to these species was considered and mitigation measures have been identified. Mitigationmeasures will need to be incorporated into the construction and dredging environmental management42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-109

plans. The consideration of sound and noise barriers to avoid impact upon avifauna was addressed ingreater detail in response to Submission 12 previously.10.5.3 Submission #19 The potential impacts on marine habitat, communities and a number of critical species areconsidered unacceptable. No substantial detail of the offsets program was provided. Scientificliterature indicates little experience and less success in proven seagrass bed replanting/reinstatementprograms.Direct, indirect, permanent and temporary impacts on marine habitats, communities and species ofconservation significance were identified under the WB EIS in Chapter 9 (and the relevant appendicesthat supported this chapter). Mitigation measures to ameliorate impacts were also addressed. Whereimpacts are not able to be addressed, offsets must be implemented.GPC is undertaking detailed negotiations with regulatory agencies regarding a whole of business offsetsstrategy acceptable to regulatory agencies. This strategy is to incorporate all impacts related to theProject that are unable to be mitigated, but to date has not identified replanting (mangroves etc.) as anoption. See Section 12 of this document for details.10.6 Terrestrial Habitat10.6.1 Submission #12 Further explanation of mitigation measures for disturbing essential koala habitat (RE 12.3.3).The area mapped as essential habitat for koalas will not be directly disturbed as a result of the Project.None of this habitat will be removed. The Project has the potential to generate additional noise and lightdisturbance (indirect impact) to the ambient levels experienced at the terrestrial environment adjacent tothe Reclamation Area. Given the size of this vegetated tract, any koalas that occur within thisenvironment would have the ability to move if disturbed to non-impacted vegetation or they may adapt tothe disturbance. This species often occurs in urban environments with noise and light disturbances, andit is considered that the Project will not generate a significant impact to this habitat or species.Weed and pest management plans for construction and operational works will assist in maintaining thecondition of the terrestrial environments adjacent to the Reclamation Area to avoid any impacts beyondthose predicted to occur.10.6.2 Submission #12Uncertainty concerning the extent of endangered RE 12.3.3, and obligations for offsets.Section 3.4.2 of the Terrestrial Ecology Report (Appendix P of the WB EIS) summarised the extent of thevegetation community described by REDD as RE 12.3.3. The field surveys identified anomalies with theon-ground communities and the RE and Moratorium Mapping, remapping other areas as this community.Field surveys also confirmed that this terrestrial area will not be disturbed by the Project and, as such, anofficial remapping is not planned for submission.No impacts are predicted for this vegetation community or the areas currently mapped as RE 12.3.3.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-110

10.7 Risk Assessment10.7.1 Submission #11Remove reference to creation of interstitial habitat creation. Negative impact upon natural condition(see also comment 11.27).The information in the table has been separated to remove the positive effects from the marine ecologyrisk assessment, and in any future documentation will be moved to a separate table to highlight positiveecosystem offsets of the proposal. Studies undertaken in Port Curtis by Currie and Small (2005) foundthat throughout the eight years of the survey, species abundance and richness was lowest on fine muddysediments in the intertidal area and highest in the coarse, sandy sediments that generally occurred in thedeeper channels. The formation of complex three dimensional surfaces on the proposed bund wall canact as a fish attraction devise by increasing the ecosystem complexity and population numbers throughthe provisioning of more ecological niches.10.7.2 Submission #12Disagree with methodology and results of risk assessment, especially direct loss of habitat anddegradation of water quality. Provide more substantial detail concerning description of offsets.Given that there are no international standards for risk management, the risk assessment methodologyfor this project was based on the Australian Standard AS/NZS 4360: 1999 Risk Management (theStandard) and HB 203: 2000 Environmental Risk Management – Principles and Process (theGuidelines). The Standard and Guidelines set out a generic framework for establishing the context,identifying, analysing, evaluating, treating, monitoring and communicating risks.Although a semi-quantitative methodology was used to conduct the risk assessment, the resultant riskestimation is relative. The risk estimations do not imply an absolute scale of risk that can be applied toany other situation or assessment, and are specific to the context and scale at which it was applied.The management of the water quality, including turbidity, has been considered in the engineering designof the reclamation and will be managed through an Environmental Management Plan (EMP) for theProject. This plan would be developed prior to any works and would address specific control measuresand monitoring requirements. Monitoring will enable reactive management of decant to occur. For moredetail on the potential impact of the decant outfall on turbidity refer to Appendix K Water Quality, of theWB EIS.GPC is undertaking detailed negotiations with regulatory agencies regarding a whole of business offsetsstrategy acceptable to regulatory agencies. Refer to Section 12 for more details.10.7.3 Submission #11 Rewriting of risk assessment table Chapter 19, Page 28 to remove sentence "small risk of directinjury to fauna" as it contradicts the risk assessment scores.Remove items with “positive benefit” risk scores from the marine ecology risk assessment.These changes of wording have been acknowledged, and will be reflected in any future documentation.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-111

10.7.4 Submission #18Conditions required for baseline seagrass sampling re: seasonal and interannual changes; postdredgerecovery monitoring for at least 3 years; hydrodynamic and plume modelling includingmonitoring of light levels at key locations - to assist dredge mitigation plan.DEEDI and PCIMP currently undertake a number of monitoring programs, including seagrassassessments, in Gladstone. It is understood that these programs will continue and likely expand toinclude negotiated offset monitoring program commitments. GPC is currently negotiating offsetrequirements for the Project and support for DEEDI is expected to be included. As such, baselineseagrass sampling requirements are expected to be determined by GPC in consultation with DEEDI. Itwould be expected that pre-dredge, during dredge and post-dredge monitoring of sensitive habitats andreference areas would be conducted. It is also expected that, in order to adequately inform and enablereactive management of dredging impacts, water quality monitoring programs would be aligned with sitessampled for seagrass health.Figure 10-1 presents suggested indicative sites for potential habitat monitoring. Sites have been placedat sensitive primary producer habitats within the predicted plume area in order to identify the actualindirect impacts of the dredging program. Also nominated are sites at the plume boundary, and atreference locations outside the predicted plume area, which will allow for the spatial decay of the plumeto be measured.A habitat monitoring program should be tied into water quality dredging monitoring program and refinedduring the planning of the dredging activities as part of the Dredge Management Plan (DMP). While it isexpected that monitoring will be undertaken prior to, during and post dredging, the duration of each of themonitoring stages should be refined once the exact dredging plan program and conditions fromDEEDI/offset negotiations are known. This should be provided in the DMP.10.8 Biosecurity (Weed and Pest Management)10.8.1 Submission #18The development of a Biosecurity Management Plan for all terrestrial invasive species be developedfor the Port of Gladstone Western Basin Dredging and Disposal Project EIS.The indirect degradation of terrestrial habitats due to weed and pest species is identified as a potentialimpact of the Project (refer Table 4-1 Risk Assessment for Terrestrial Flora and Fauna of the TerrestrialEcology Report, Appendix P of the WB EIS). The EMP for the Project will, accordingly, incorporatemeasures to manage and mitigate introduced species to the terrestrial environment.10.8.2 Submission #18Undertake a risk assessment for high biosecurity risk species and sites (e.g. current location) anddevelop threat mitigation plans for them (e.g. clean down and inspections at high risk sites).The indirect degradation of terrestrial habitats due to weed and pest species is identified as a potentialimpact of the Project (refer Table 4-1 Risk Assessment for Terrestrial Flora and Fauna of the TerrestrialEcology Report, Appendix P of the WB EIS). The EMP for the Project can achieve this process by42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-112

undertaking a risk assessment for all potentially introduced species and developing measures to manageand mitigate the of concern species. This will be in accordance with requirements to mitigate introductionof, and impacts from, species of concern for the Gladstone region.10.8.3 Submission #18Plan and the locally declared weed and pest animal species under the Local Government model lawsmust be considered in the Weed and Pest Animal Management Plans for each existing or proposedoperational area in the Port of Gladstone Western Basin Dredging and Disposal Project Site.The indirect degradation of terrestrial habitats due to weed and pest species is identified as a potentialimpact of the Project (refer Table 4-1 Risk Assessment for Terrestrial Flora and Fauna of the TerrestrialEcology Report, Appendix P of the WB EIS). As noted in Section 10.8.2, the EMP for the Project willincorporate measures to manage the spread and introduction of weed and pest species to the Projectarea and adjacent habitat.The report identifies the weed species declared under state legislation, though it is acknowledged thatthe species identified under the local government laws are also important for inclusion in managementand mitigation for the EMP.10.8.4 Submission #18Develop and initiate a Marine Pest Management Plan to monitor for marine pests and mitigate therisk of spread into and within the marine facilities of the site (Submitter DEEDI, page 20).A marine pest assessment of all organisms collected during the survey was undertaken by identifying tospecies level any taxa that were recognised as being morphologically similar to recognised pests (asdefined by the Australian Government, www.marinepests.gov.au). No introduced marine pest taxa weredetected during any phase of the marine ecology sampling across the Port Curtis area.In Australia, management of marine pest issues including potential for introduction, spread anderadication, is achieved through the Australian Government’s National System for the Prevention andManagement of Marine Pest Incursions (the National System). The National System includes a range ofmeasures to deal with all aspects of the prevention, management and control of marine pestintroductions. Addressed under the National System are arrangements to reduce the risk of primaryinvasions via ballast water or biofouling, as well as measures to control the spread of existing introducedmarine pests (IMP) as a result of secondary invasions.Under the National System, eighteen port locations in Australia have been identified for ongoingmonitoring for marine pests. Recognising the ongoing high risk of introduction to this area, the Port ofGladstone is one of these 18 ports. The Port is to be monitored as part of the National System using newmonitoring guidelines developed by Commonwealth Department of Agriculture, Fisheries and Forestry(DAFF), in conjunction with other agencies and technical specialists. These guidelines seek to providestandardised approaches to the design, conduct and reporting of each of the marine pest monitoringevents. The marine pests of concern to be monitored for using the guidelines focus on those previouslyidentified by a range of ballast and biofouling and vector studies to be of risk to Australian waters. Thislist currently includes 55 different species but is subject to change. The most current list of species isavailable by contacting the National System (www.marinepests.gov.au).42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-113

Monitoring of marine pests within Gladstone under the National System has not yet been undertaken andan extensive period of time has elapsed since the previous pest surveys. This process is, however, notthe responsibility of GPC as all marine environments and processes that could potentially host orintroduce a marine pest should be considered under National System monitoring, not just commercialshipping operations. As such, a National System marine pest monitoring program for Gladstone willincorporate habitats associated with recreational vessels, aquaculture industries and other stakeholdergroups at risk of introducing a marine pest. Areas associated with the Western Basin reclamation workswill be incorporated into that National System monitoring program if determined to be risk environmentsthat require regular monitoring. Additional monitoring by the project over and above National Systemrequirements during operation of the reclamation facility is not deemed necessary as National Systemmonitoring will address this consideration.Management measures to mitigate against potential to introduce any marine pests during constructionshould, however, be implemented. This would include adherence to Commonwealth and State biofoulingand ballast water management requirements. These include exchange of high risk ballast prior to entryinto Australian waters and to make sure that dredgers and construction equipment are free of high riskbiofouling prior to site entry. This may require pre-entry inspection of vessels, particularly dredgers, todemonstrate they are not carrying pest species. These mitigation measures were identified in the WBEIS in Chapter 9 and Appendix Q and should be included in the construction management plan.10.9 Other Matters10.9.1 Submission #5Correct references to Shell LNG projects details, some names and references are incorrect.Names and references were corrected in the form of a corrigenda posted on the GPC website on 7 thJanuary 2010.10.9.2 Submission #11Remove or replace the expression “natural underwater noise”.The term natural underwater noise was designed to encompass both anthropogenic and biological noisecurrently occurring in the region. A change of wording to ‘existing ambient underwater noise’ will bereflected in any future documentation.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document10-114

11. FisheriesA number of submissions related to fisheries. A general response is outlined below.11.1 Impacts on HabitatThere is concern that removal of soft sediment habitat resulting from the construction of the ReclamationArea will reduce the available juvenile fishery species habitat, having flow-on effects to catch rates andeconomic viability of the fishery in future. There has also been suggestion that compensation for suchlosses may be appropriate. In terms of compensation, GPC has indicated throughout the EIS documentthat it will participate in any Queensland Government lead forum/discussion on the matter. However,while the loss of an area of benthic habitat is documented, rock revetment walls also provide interstitialfishery habitat both tidally and subtidally, offering a greater quantity of spatial refuge for juvenile taxathan does the existing open seabed. It is therefore also noted that the fishery communities are alreadyadapted to using other meadows in the Gladstone region for those times during which seagrassmeadows in the Western Basin are sparse (e.g. 2005).Seagrass meadows are recognised to be important juvenile fishery species habitat (Chartrand et al.2008) providing refuge and food resources. Consultation with the local commercial fishing communityrevealed that there are approximately six commercial operations that utilise the Project Area andadjacent surrounds. The main activities that occur in this area are setting pots to collect mud crab, fishnetting, and trawler thoroughfare (but no trawling). Species targeted by the local commercial fishingindustry include mud crab, mullet, shark, blue salmon, and barramundi. Each of these species could usethe Project Area as juvenile habitat at some other stage of their life cycle.The seagrasses within the area to be impacted (Halophila decipiens and Zostera capricorni) occur inaggregated patches, have little vertical structure and are highly variable in their prevalence. This isclearly demonstrated by the variability in meadow area mapped by DEEDI since 2002, as reportedChartrand et al. (2008). For instance, the subtidal meadow in the footprint of the Project virtuallydisappeared in 2005, dropping to only 7 hectares in size from a previous area of 284 hectares measuredin 2004. By 2008 the meadow had still not recovered to the full extent of the previously monitored area,and was mapped to cover 242 hectares (Figure 11-1).Commercial fishery data for the Gladstone area (CFISH and unpublished DEEDI data) from 2002 to2008 do not show a decline in catch in the years following a decline in available seagrass habitat. Thiswould be expected if the reproductive success of species using the habitats to be affected was tightlylinked to the availability of that habitat. Instead, a decline in catch is observed corresponding with thetime of reduction in available habitat, suggesting that commercially targeted species prevalence wasmore affected by those events that lead to the loss of seagrass than they were by the loss of actualseagrass itself. Chartrand et al. (2008) note that climatic conditions, including rainfall, are likely drivers ofmeadow change for Port Curtis/Gladstone, however, declines in 2005 were not linked to excessiverainfall events or different temperature conditions for the region. The contraction of the intertidal meadowwithin the Project footprint did, however, correspond with an observed decline in the average daylighthours that intertidal banks were exposed to in Gladstone. This suggests that the intertidal meadow in the42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document11-115

footprint of the Reclamation Area may be driven by light availability more than rainfall and variation infactors associated with rainfall.Those meadows that will not be directly affected by reclamation activities are expected to be indirectlyaffected by dredging works, increasing turbidity loads resulting in a loss of light penetration. Accordingly,temporary losses from indirect impacts may also occur in the meadows of the Project footprint duringdredging works. However, recovery is expected to occur upon completion of dredging works.The seagrass meadows in the direct footprint of the Project, as mapped by DEEDI since 2002, represent11.2% of available coastal seagrass habitat within port boundaries in the Fitzroy region andapproximately 2.6% of the seagrasses across all environments of the Fitzroy region (Gladstone Harbour,Shoalwater Bay but not Rodds Bay) as reported by Coles et al. (2007; refer to Section 10.1.1 for moredetails). Given the highly variable ephemeral nature of the meadows in the Project footprint, species thatdo use this habitat when it is present would already have to relocate to the other meadows in the portenvironment when the footprint meadows are highly contracted/absent. This natural retraction of themeadows demonstrates that removal of the meadows in the footprint is not likely to have flow on affectsto fisheries productivity. This is further supported by the observation that fisheries catch (effort notaccounted for) did not decline following the 2005 natural reduction in this available habitat (Figure 11-1).Given that catch decreased in 2005 at the same time as the habitat reduction it is likely that whateveraffected the habitat may have also affected the catch. The catch recovered at the same rate as themeadow indicating the loss of meadow did not affect the catch in later years.It is evident that the communities using this habitat already persist under a fluctuating regime of meadowavailability and absence. The composition of the intertidal meadow within the Project footprint isdominated by Zostera capricorni, which is recognised as a key nursery species for commercial andrecreational fisheries species (Chartrand et al., 2008; and references therein). The composition of thismeadow is not unique to the local region, nor are the temporal trends that the meadow displays (referFigure 11-2 for examples of nearby Z. capricorni meadow temporal trends). It is, therefore, predicted thatany species using the habitat to be affected will relocate to the other, extensive (approximately 7,000hectares) seagrass meadows available in the Gladstone area. Given this, it is suggested that there willnot be significant impacts on the juvenile fishery productivity in this area as a result of habitat alteration.11.2 Compensation/OffsetsRefer to Section 12.2 for details on the offset process that will be implemented for this and other portprojects.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document11-116

Area of seagrass (ha ± R)70060050040030020010002002 2004 2005 2006 2007 20087006005004003002001000Commercial catch (tonnes)Seagrass (Meadow 8 and 9)Commercial CatchFigure 11-1 Temporal trends in seagrass area (Meadow 8 and 9) and commercial catch700700Area of seagrass (ha ± R)600500400300200100600500400300200100Commnercial Catch (tonnes)02002 2004 2005 2006 2007 20080Meadow 8 (within footprint)Meadow 5 (outside footprint)Meadow 6 (outside footprint)Commercial CatchFigure 11-2 Temporal trends in Zostera capricorni meadows and commercial catch in the vicinityof the Project Area42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document11-117

12. Offset Policy12.1 Offsets StrategySubmissions #2, #4, #11 and #12Suggestions that the proponent should develop an offset proposal or strategy to compensate for thedirect and indirect impacts arising from the project.Suggestions that as it is inevitable that unavoidable environmental impacts will occur, an offsetproposal or strategy to compensate for the direct and indirect impacts arising from the project shouldbe presented. Such a proposal must comply with the Queensland Government Environmental OffsetPolicy 2008, the more specific Queensland Fisheries’ Offset Policy (Fish habitat ManagementOperational Policy (FHMOP 005) and the draft Commonwealth offset policy. The EIS should clearlydefine and quantify what unavoidable impacts will occur and present realistic/achievable options as tohow they can be offset to meet a net gain of coastal resources.Offsets against habitat removal should be more clearly developed and described, demonstratecoordination of (offset) objectives with management authorities and strategic plans and policies.Provide a stand alone section in the EIS describing proponent’s commitments to offsets and howthey satisfy requirements of existing habitat values that will be lost as a result of the project. Describehow offsets satisfy Queensland policy for offsets.Move from considering offsetting destroyed mangrove and seagrass to committing to offsetting.GPC should commit to offsetting in order to meet ESD objectives and to leave a positive ecologicallegacy for future generations while protecting biological diversity.Improve the discussion providing rationale for compliance with NSESD objectives and PrecautionaryPrinciple (e.g. commit to detailed offsets - not just consider).Improve the rationale for compliance with Ecological Sustainable Development, as it has not beensufficiently demonstrated in the EIS.The proposed offset must become ecologically equivalent to the area proposed for clearing.In response to the range of submission comments above, an offsets package has been proposed, and isin the process of refinement, in preparation for sign off from the relevant agencies. This packageprovides compensation for both direct and indirect impacts, even though many of the indirect impacts willnot be permanent.The proposal will conform with government requirements, as negotiations have involved the Departmentof Infrastructure and Planning, and other key agencies.It is not possible to provide more details of the offsets package at this time, as they have not beenreleased. Offsets are being negotiated in parallel to the EIS, and make use of the predicted impacts.GPC recognises that the proposed reclamation will directly impact/remove marine habitat for whichoffsets are proposed, and that additional areas will be impacted/lost in the short-term as a consequenceof turbid plumes for the duration of dredging.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document12-118

GPC continues to work with Queensland Primary Industries and Fisheries (QPIF) and the Department ofEnvironment and Resource Management (DERM) to develop an appropriate environmental offsetspackage for the Western Basin Dredging and Disposal Project.The primary options being considered include:Surrendering areas of land/habitat in perpetuity for environmental & ecological purposes; andProvision of funding for substantial fisheries/marine fish habitat initiatives. These initiatives embracea broad range of issues including fish habitat connectivity, function, protection, research and threatremoval.The finally agreed offsets requirements will be included as conditions to approvals. More specific detailson the offsets package will be available at this time.12.2 Fisheries CompensationSubmissions #3, #6, #16 and #18 have raised the issue of compensation, as follows:Various calls for compensation to local fishers.Calls for compensation to be made available to commercial fishers who regularly work in the area.Submission #18 proposes that any approval require the proponent to contribute financially or in kindto the management of impacts related to loss of recreational fishing and reduced viability ofcommercial fishing.Submission #3 suggests compensation for the loss of productive fishing areas to commercialfishermen as a condition from the Coordinator General.As discussed within the WB EIS, an offsets package has been negotiated by GPC in consultation withFisheries and other regulatory agencies to compensate for project-related impacts that cannot bemitigated, including the loss of marine habitat. GPC recognises the importance of maintaining the healthof the harbour with regard to water quality as well as maintenance of marine life in general. As aconsequence, the offsets package includes a significant level of funding to provide for studies related tothe maintenance and enhancement of marine biodiversity within the port. While it is recognised that theproposed development will restrict access to some areas within the Western Basin, GPC believes thatthese restrictions have minimal affect on the use of the harbour. Some netting activity (in theReclamation Area) will be impacted, particularly given that much of the Western Basin habitat area to beaffected is very shallow and accessible at certain tidal phases. While the affects on fish numbers isunquantified, substantial alternative fish habitat will be created via construction of the bund. As this areawill no longer be accessible for netting activities, a net loss of fisheries productivity of the Project Area isnot anticipated.GPC has previously indicated willingness to coordinate meetings with fishermen (commercial andrecreational), the various regulatory agencies and LNG proponents to discuss impacts and evaluatepotential offsets in addition to those already committed.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document12-119

12.3 Kangaroo Island AirportSubmission #3 suggests that the State be responsible for addressing the loss of the Kangaroo IslandAirport site should the Western Basin Project proceed. This issue has been dealt with as part of theoffsets package.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document12-120

13. Acid Sulfate Soils13.1 Bund Construction13.1.1 Submission #2Inconsistency in statements regarding the effect of bund wall construction on Acid sulfate Soil (ASS)disturbance; clarify statements regarding reclamation area acid sulfate soil buffering capacity andeffect of bund wall construction.It is considered that a maximum two metres thickness of sediments is likely to be disturbed in responseto bund wall construction, as a result of heaving from rock placement (page 50 of Appendix I of WB EIS).Reference to Appendix I, Figure 3.20 and Figure 3.21, indicates that within the upper 2 m of sediment,just over half of the locations within the footprint of the Reclamation Area report net acidity in one or moresamples and that the majority of locations report one or more samples with a chromium reducible sulfuracidity of >18 mol H + /tonne, indicating Potential Acid Sulfate Soil (PASS). Review of laboratory resultsand borehole logs indicates that the Acid Neutralising Capacity (ANC) is typically greatest between 0 and0.5 m depth below the seabed, with the greatest potential for neutralisation of acid within this upper0.5 m layer. The majority of the sediments between 0.5 and 2 m do not have enough ANC to neutraliseacid that may be produced as a result of oxidisation.Shallow PASS materials beneath and in the vicinity of the bund footprint will be disturbed as a result ofbund construction and may result in some lateral and vertical displacement of PASS. As a result, somePASS may be exposed to the air with the potential to oxidise and generate acid. However, this is morelikely in shallower areas - that is along the western wall, and the western part of the western wall, as mudwaves formed in other areas are more likely to remain under water at all times. The proposedmanagement of PASS for bund construction is outlined in Section 4.1.2 of Appendix I of the WB EIS andalso included in the Acid Sulfate Soil Management Framework (refer to Appendix E of this document).13.2 ASS Mapping13.2.1 Submission #2Lack of borehole labels on Figures 3-12 to 3-18, Figure 3-20 and 3-21 of Appendix I of the WB EISand on Figures 5-8, 5-9 and 5-10 of Chapter 5 of the WB EIS.Appendix E of Appendix I, borehole data are not indicated on a site plan.These comments are addressed by the core location reference plans provided in Appendix F. Thereference plans show the core identifiers referenced in the WB EIS text (1A-01 for example) and theaccompanying table correlates the core identifiers referenced in the WB EIS text to the original coreidentifiers (#4632 for example) which correspond to the borehole log numbering system and to the ASStest results presented in Appendix E of Appendix I of the WB EIS.ASS mapping, inconsistency with copyright agreement (Figure 3-1 and 3-2 of Appendix I of the WBEIS).42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document13-121

Figure 3-1 and 3-2 of Appendix I have been amended to include the copyright notice and are included inAppendix F.No borehole logs provided for data in Appendix E, of Appendix I of the WB EIS.The borehole logs have been included in Appendix G of this document.13.3 ASS Occurrence and Sampling13.3.1 Submission #2No estimate of the volume of dredge spoil containing PASS requiring treatment was provided in theWB EIS.Information regarding acid sulfate soil material is inadequate.The sediments within the dredge footprint that reported a net acidity (i.e. >=18 mol H + /tonne) typicallycomprise soft silt/clay materials (i.e. Holocene-age marine mud). These sediments have been identifiedwithin each of the dredge stages, with net acidity typically in the range 200 to 500 mol H + /tonne.Sediments that reported levels of oxidisable sulfur above the action criteria of 0.03%S, but with netacidity

Given that more than 10,000 tonnes of PASS will be disturbed (see Table 13-1) with typically up to 1%oxidisable sulfur, the material falls into the Extra High treatment category of the Queensland Acid SulfateSoil Technical Manual, Soil Management Guidelines (2002).The occurrence of PASS for each investigation location within the dredge footprint is illustrated in Figure13-1, Figure 13-2 and Figure 13-3. Reference plans showing the borehole location identifiers areincluded in Appendix G of this document. Each investigation location has been colour coded according tothe presence or absence of PASS and presence of net acidity in the samples. The following pointsexplain the colour coding on the figures:Grey dot – location has been sampled for ASS but the laboratory analysis results (i.e. from SPOCASor Chrome Suite analysis methods) have not yet been processed.Dark green dot – all of the samples for the location reported oxidisable sulfur values of 0.02%S or avalue of 3 times the level of oxidisable sulphurRed dot – one or more samples for the location reported oxidisable sulfur values of 0.03% and above(indicating PASS) with an ANC

312,000313,000314,000315,000Friend PointLaird PointBased on or contains data provided by the State of Queensland(Department of Natural Resources and Water) 2004. Inconsideration of the State permitting use of this data youacknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness,currency or suitability) and accepts no liability (including withoutlimitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data.Data must not be used for direct marketing or be used in breach ofthe privacy laws.NorthPassageIslandSouthPassageIsland7,368,0007,368,0007,369,0007,369,0007,370,0007,370,0007,371,0007,371,0007,372,0007,372,000NOTES:Fisherman's LandingPASS - Potential Acid Sulfate SoilANC - Acid Neutralising CapacityPASS and net acidity - defined by SCR >= 18 mol H+/tonne, coloured dot indicates presence in one or more samples at the location.no PASS - defined by SCR 3 times SCR - coloured dot indicates this is true for all samples at the location.ANC3 times SCR)no PASS (but net acidity)313,000PASS (ANC3 times SCR)PASS (net acidity)Western Basin ReclamationFisherman's Landing Northern Expansion314,000Existing Channels, Swing Basins and BerthsProposed Dredge StagesStage 1AStage 1B315,000Stage 2Stage 3Stage 41:25,000 (at A4)o0 200 400 600 800 1,000MetresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of Australia 1994Grid: Map Grid of Australia, Zone 56G:\42\15386\GIS\WesternBasinSupplementaryEIS\Mxd\4215386-56_402_revB.mxdPort of GladstoneWestern Basin Supplementary EISIndication of Potential Acid Sulfate Soil,Fisherman's Landing, Laird Point andFisherman's Landing Swing BasinJob Number 42-15386Revision BDate 14 April 2010Figure 13-01Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.com© 2010. While GHD has taken care to ensure the accuracy of this product, GHD and DATA CUSTODIANS (GPC, DERM) make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.GHD and DATA CUSTODIANS cannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses,damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data Source: DERM - Aerial Photo (flown 2007) 2009; GPC - Proposed Dredge Channels, Existing Channels; GHD - monitoring Locations.

Tide Isla7,372,000315,000316,000317,000318,000319,000Based on or contains data provided by the State of Queensland(Department of Natural Resources and Water) 2004. Inconsideration of the State permitting use of this data youacknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness,currency or suitability) and accepts no liability (including withoutlimitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data.Data must not be used for direct marketing or be used in breach ofthe privacy laws.7,372,000NorthPassageIsland7,370,000Curtis IslandSouthPassageIsland7,368,0007,368,0007,369,0007,369,0007,371,0007,370,0007,371,000Fisherman'sLanding7,367,000Hamilton Point7,367,0007,366,000NOTES:7,366,000PASS - Potential Acid Sulfate SoilANC - Acid Neutralising CapacityPASS and net acidity - defined by SCR >= 18 mol H+/tonne, coloured dot indicates presence in one or more samples at the location.no PASS - defined by SCR 3 times SCR - coloured dot indicates this is true for all samples at the location.ANC3 times SCR)no PASS (but net acidity)316,000PASS (ANC3 times SCR)PASS (net acidity)317,000Proposed Dredge StagesStage 1AStage 1B318,000319,000Stage 2Stage 3Stage 4Existing Channels, Swing Basins and Berths1:30,000 (at A4)o0 200 400 600 800 1,000MetresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of Australia 1994Grid: Map Grid of Australia, Zone 56G:\42\15386\GIS\WesternBasinSupplementaryEIS\Mxd\4215386-56_400_revB.mxdPort of GladstoneWestern Basin Supplementary EISIndication of Potential Acid Sulfate Soil,North Targinie Channel,Western Basin & Hamilton PointJob Number 42-15386Revision BDate 14 April 2010Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.com© 2010. While GHD has taken care to ensure the accuracy of this product, GHD and DATA CUSTODIANS (GPC, DERM) make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.GHD and DATA CUSTODIANS cannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses,damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data Source: DERM - Aerial Photo (flown 2007) 2009; GPC - Proposed Dredge Channels, Existing Channels; GHD - monitoring Locations.Figure 13-02

319,000320,000321,000322,000323,000324,0007,368,000Based on or contains data provided by the State of Queensland(Department of Natural Resources and Water) 2004. Inconsideration of the State permitting use of this data youacknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness,currency or suitability) and accepts no liability (including withoutlimitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data.Data must not be used for direct marketing or be used in breach ofthe privacy laws.7,368,0007,367,000Hamilton Point7,367,000Tide IslandDiamantina IslandPicnic IslandWiggins Islands7,364,0007,364,0007,365,0007,365,0007,366,0007,366,000Gladstone Marina7,363,000NOTES:7,363,000PASS - Potential Acid Sulfate SoilANC - Acid Neutralising CapacityPASS and net acidity - defined by SCR >= 18 mol H+/tonne, coloured dot indicates presence in one or more samples at the location.no PASS - defined by SCR 3 times SCR - coloured dot indicates this is true for all samples at the location.ANC3 times SCR)no PASS (but net acidity)320,000PASS (ANC3 times SCR)PASS (net acidity)321,000Proposed Dredge StagesStage 1AStage 1B322,000323,000Stage 2Stage 3Stage 4Existing Channels, Swing Basins and Berths324,0001:30,000 (at A4)o0 200 400 600 800 1,000MetresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of Australia 1994Grid: Map Grid of Australia, Zone 56G:\42\15386\GIS\WesternBasinSupplementaryEIS\Mxd\4215386-56_401_revB.mxdPort of GladstoneWestern Basin Supplementary EISIndication of Potential Acid Sulfate Soil,South Targinie Channel,Clinton Bypass ChannelJob Number 42-15386Revision BDate 14 April 2010Figure 13-03Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.com© 2010. While GHD has taken care to ensure the accuracy of this product, GHD and DATA CUSTODIANS (GPC, DERM) make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.GHD and DATA CUSTODIANS cannot accept liability of any kind (whether in contract, tort or otherwise) for any expenses, losses,damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data Source: DERM - Aerial Photo (flown 2007) 2009; GPC - Proposed Dredge Channels, Existing Channels; GHD - monitoring Locations.

13.3.2 Submission #4It was noted that insufficient sediment sampling for Stage 4 of the project had been done by the timeof publication of the WB EIS and that DEWHA understand that work has since been undertaken.GPC was provided with the sediment sampling results used in the ASS assessment conducted for theWB EIS and the adequacy of the data collected was under the control of the data providers. Additionallaboratory results have become available since the issue of the WB EIS for locations within and adjacentto all of the dredge areas and are summarised in Appendix H of this document.13.3.3 Submission #11Methodology for ASS analysis used in the WB EIS was a pilot study resulting in a decreased numberof samples as specified by a draft SAP. Undertake full range of sampling and analysis as outlined inNAGD.Sampling for the marine sediment quality assessment and for the ASS assessment is addressedseparately and each has different sampling guidelines. ASS investigation is triggered by the StatePlanning Policy 2/02: Planning and Managing Development Involving Acid Sulfate Soils (SPP2/02).Information regarding conduction of an ASS investigation is contained in the Guidelines for Sampling andAnalysis of Lowland Acid Sulfate Soils in Queensland 1998 (QASSIT, Queensland Acid Sulfate SoilsInvestigation Team). Sampling for the marine sediment quality assessment, which is an assessment ofthe contamination status (excluding ASS) of the sediment, is governed by the NAGD.QGC procured an ASS geomorphological modelling study of the proposed dredging areas covered bythe WB EIS to demonstrate the understanding of ASS occurrence and hence provide justification for anASS sampling regime of lower intensity than detailed in the Guidelines for Sampling and Analysis ofLowland Acid Sulfate Soils in Queensland 1998.Undertake ASS sampling and analysis of areas adjacent to the Western Basin reclamation area asthere may be disturbance of this area. Fisherman’s Landing reclamation area is specificallymentioned.It is proposed to widen the existing Fisherman’s Landing as part of the Fisherman’s Landing NorthernExpansion EIS (GHD 2009c) to allow for continued access of the existing reclamation during constructionof the Northern Expansion and the Western Basin Reclamation Area. The project description (Chapter 2(Project Description), page 2-15, 2 nd paragraph of the WB EIS) states that there is no requirement forupgrade, relocation, realignment or deviation of other infrastructure as part of the construction phase ofthe Project. Hence, ASS sampling and analysis of the existing Fisherman’s Landing has not beenconducted.ASS sampling and analysis of marine sediment has been conducted to the north of the Western BasinReclamation Area in addition to the sampling conducted for the footprint of both the Western BasinReclamation Area and Fisherman’s Landing Northern Expansion. The test results for these areas areincluded in Appendix E of Appendix I of the WB EIS. Assessment of the results for the purposes of theWB EIS is included in Section 3.7.3 of Appendix I of the WB EIS.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document13-127

13.3.4 Submission #12Justify and shorten the timeframe for PASS assessment of an area to be dredged as 6 months isbelieved to be too long.The six month timeline proposed for ASS assessment prior to dredging is considered to be more thanadequate given that no significant change in sediment type (and hence occurrence of sulfides) is likely tooccur within this timeframe. However, if a large sediment deposition event was to occur between the timeof assessment and commencement of dredging then further assessment might be warranted. The sixmonth timeframe proposed is considerably less than the NAGD timeframe of five years for contaminantassessment for ocean disposal.13.4 ASS Management13.4.1 Submission #2Demonstrate that dredge spoil containing Acid Sulfate Soils (ASS) can be managed short and longterm.This is responded to in the Acid Sulfate Soil Management Framework which includes the key workingprinciples of managing the dredge spoil, included as Appendix E.The framework outlines the key principles of managing the Acid Sulfate Soil (ASS) component of bundconstruction, dredging, placement of sediment into Reclamation Area and post placement testing andmonitoring. The framework presents the likely management strategy as well as ‘back-up’ managementoptions. This framework will form the basis of the Acid Sulfate Soils Management Plan (ASSMP) to beagreed with DERM and put in place prior to the start of construction.The dredge placement methodology outline is provided in Chapter 4 (Section 4.2).13.4.2 Submission #2 Also of concern is the lack of any measure to mitigate dispersal of acid sulfate soil fines from dredgeoverflow although this may disperse some 10 times the amount released by bottom dumping.No Actual Acid Sulfate Soils (AASS) were indicated for the proposed dredge areas or for the footprint ofthe Reclamation Area, based on the available data for the WB EIS. Therefore the generation of acid,through disturbance of AASS is not considered as a likely potential impact of the dredging process.It is recognised that although sulfide fines suspended in the water column do have the potential tooxidise in the water column as they settle back to the seabed, oxidisation in the water column is notconsidered to be an issue given that the reaction rate in water will be significantly slower than in air asmuch less oxygen is available for a reaction to occur. GPC advise that the dredge overflow will beminimal (refer to Chapter 5). In addition, the use of the CSD method of dredging for the majority of thefootprint will help to minimise any potential for the dispersal of acid sulfate soil fines.Sulfide fines that do become suspended in the water column will either be re-distributed to a deep waterenvironment or settle out of suspension in the near shore inter-tidal environment.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document13-128

Re-distribution in the deep water environment will not significantly change the existing conditions, giventhat:PASS is indicated to be present within the proposed dredge areas and is also highly likely to bepresent in many adjacent areas not sampled; andSediment plume modelling of predicted depositional rates for dredging of the Targinie Channel andimmediately east of the Project reclamation footprint (refer to Figure 13-4) predicts the highest ratesof deposition in the immediate vicinity of the dredge vessel (red in colour on the figure).Settlement of sulfide fines out of suspension in the inter-tidal environment is not anticipated tosignificantly change existing conditions, given that:Investigations show that the inter-tidal environment already contains PASS with similar (and higher)levels of oxidisable sulfur within 0.1 m of the seabed to the levels of oxidisable sulfur identified in thedredge stages. Reported values of S CR for the Reclamation Area (inter-tidal) range from 0.02 to2.1%S (0 to 0.1 m below the seabed), but are more typically in the range 0.1 to 1.0%S and forlocations close to Curtis Island values of S CR are typically in the range 0.3 to 1.1%S (0 to 0.1 m belowthe seabed). The typical range of oxidisable sulfur (above the action criteria of 0.03%S) within thedredge stages is 0.03% to 1%S.Shell fragments, and hence ANC, which are already present in the inter-tidal environment, are alsolikely to continue to accumulate thereby providing a mechanism for neutralising any acid generatedfrom oxidisation of sulfides. This is supported by the current conditions where shallow sediments(sampled from 0 to 0.1 m) in the Reclamation Area with reported oxidisable sulfur in the range 0.1 to1.0%S typically report a net acidity of

Figure 13-4 Spatial plume TSS sedimentation (m/day) for the DECANT + FL CSD + FL TSHD (leftpanel) and DECANT + FL CSD + TC TSHD (right panel) scenarios13.4.3 Submission #11Provide information on how the redistribution of PASS material as a result of dredge overflow will bemitigated during dredging operation (Ch 5.5.3 of WB EIS).Redistribution of PASS as a result of overflow dredging is not considered to be a significant impact.Refer to Section 13.4.2 for a previous response.Furthermore, it is noted that the period of overflow dredging is typically dependent on the nature of thematerials being dredged. Where finer materials are being targeted, the use of more powerful TSHDsmeans only limited periods of overflow dredging are required. These finer materials are also more likelyto have sulfidic fines/PASS material, and hence overflow time will tend to be short for those materialswith a higher potential for PASS. The same would hold true where a CSD was used to undertake thedredging, but had to pump to a barge or TSHD rather than pumping directly to the reclamation (e.g. ifoffshore disposal were to occur). It is anticipated that the overflow time per load for the dredging of finesediments would typically be less than 10 minutes.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document13-130

14. Traffic14.1 Marine Traffic14.1.1 Submission #11Concern regarding access by Origin LNG proposal. Channel to be dredged appears to go onlyhalfway up Western Basin precinct. It is unacceptable if Origin have to construct a jetty across theeastern channel. Vessels need total access via this route as it provides shelter from prevailing winds.APLNG have put forward two alternatives for their wharf locations and it is recognised that the proposalfor a wharf on the western side of Passage Island will limit access between Passage Island and CurtisIsland. This issue is recognised as significant and will be considered in the EIS conditioning process.A general preference for the APLNG 2A option has been expressed by the majority of agencies andGPC. The final option selection will involve both the APLNG EIS and Western Basin EIS processes.14.1.2 Submission #11Identify significant increase in vessel traffic as an issue in the EIS and provide a mitigation strategythat includes ‘go slow’ areas to reduce the possibility of boat strikes.Vessel movements within the Port are subject to the control of the Harbour Master. The Harbour Masterwill be consulted on vessel movement both for operational and construction phases for the safeoperation of the port. In addition prior to any construction commencing detailed risk reviews will becarried out involving the relevant parties/organisations.Should the need for particular “go slow” areas be identified to ensure the safety of port users then theywill be implemented and be included in the Safety Management Plan.14.2 Land-based Traffic14.2.1 Submission #1 Assumptions made in the traffic analysis are inconsistent with DTMR traffic count data, and are notsupported by project specific data collection. The Supplementary EIS should undertake trafficanalysis for Gladstone-Mt Larcom Road and the intersection of Gladstone-Mt Larcom Road withLanding Road based on DTMR’s traffic count volumes attached to the DTMR submission.The DTMR-provided traffic count volumes have been used to recreate the traffic analysis that waspresented in Chapter 11 in the WB EIS. This report (Traffic Analysis report) is attached as Appendix I tothis document.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document14-131

14.2.2 Submission #1 The proponent should be aware that in addition to legislative requirements outlined in Section 1.10.3of the EIS, further permits or approvals are required to work in, or interfere with a state-controlledroad or railway and for ancillary works and encroachments in a state controlled road corridor. Anapproval to interfere with a railway is dealt with under s255 TIA.The proponent is required to undertake a railway level crossing assessment as per requirementsunder s255 TIA.No heavy vehicle crossings of the Fisherman’s Landing Branch rail line are envisaged with the preferredhaul route. Should the haul route change and the need to cross the Fisherman’s Landing Branch rail linebe required, a separate level crossing assessment will be undertaken and an associated approval of therailway crossing will be obtained from the Department of Transport and Main Roads, under Section 255of the Transport Infrastructure Act 1994.The proposed haulage road from the quarry site is currently being designed and approval applicationsare being developed. These applications are outside of the EIS process for the Western Basin Dredgingand Disposal Project. At this stage, the proposed haul road route is through State Development land,Cement Australia land, Queensland Energy Resources Limited (QER) land and a small section offorestry land. The haul route runs predominantly to the west of Landing Road crossing forestry Road tothe north and then runs parallel to Forestry Road leading to Fisherman’s Landing Wharf. Negotiationsand further discussion are being held with relevant land owners to ensure the haul route is acceptable byall relevant landholders. At this stage, the haulage route involves only one heavy vehicle crossing ofForestry Road, which will be designed in consultation with Gladstone Regional Council and QER.Refer to Appendix J for an extract from the Haul Route Options Study. It must be noted that this studywas high level and details within the report have since changed however.14.2.3 Submission #1The proponent should provide a concise explanation of:– What assessment was undertaken in the Haul Road Options Study of impacts to the railway levelcrossings on the Fishermans Landing Branch Line;– What consultation with QR has occurred; and– What compensation will be provided for damage to any rail transport infrastructure arising fromthe use of the level crossings by the haul vehicles.A Haul Route Options Study was undertaken in September 2009 by GHD. This report outlines thepotential approval limitations, vegetation constraints and cost estimates for six haul route options usingeither Council roads and/or constructed haulage roads. The report recommends two options for furtherinvestigation, including the preferred westerly haul route to Fisherman’s Landing wharf which minimisesthe use and impact on Council roads, as well as avoiding the need for rail crossings entirely. Refer toAppendix J for an extract from the Haul Route Options Study.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document14-132

15. Social and Cultural Impact15.1 Consultation15.1.1 Submission #6 and #16No consultation has ever been initiated by the GPC with commercial fishermen who rely on this areafor a substantial portion of their earnings.There was no formal consultation process undertaken by the PoGC with industry.GPC/GHD organised a consultation meeting with a number of commercial fishermen based in Gladstoneon the 2 nd July 2009. In addition, following contact from Queensland Seafood Industry Association, GPCand GHD met with representatives of this organisation on the 29 th of July. Concerns raised at bothevents were considered and incorporated in the consultation report and the Social Impact Assessment.In view of the submissions received, GPC has committed to further consultation meetings withcommercial fishermen and their representatives, with the most recent meeting (Qld Seafood Industrybriefing) held on 24 th February 2010.15.1.2 Submission #17 The public consultation process has been improper. The public has not been told about the 1000acres of seagrass beds to be lost. In the print media there has been no mention of the exact area ofseagrass to be lost.The public consultation process included several options for the general public to find out moreinformation about the Project and to provide their input. It included newspaper advertisements in theGladstone Observer on the 13 th , 27 th and 30 th of June 2009, a dedicated section in GPC's "Port Talk"distributed with the Gladstone Observer on the 6 th of June, a section on the GPC website and acommunity open day on the 1 st July 2009. Print materials including posters at the community open dayshowed the extent of the proposed dredging and Reclamation Area.GPC attended information displays at the Kin Kora shopping centre on Saturday 5 th December 2009 andThursday 17 th December 2009.In addition, a Project email and 1800-number has been available throughout the Project, allowingmembers of the community to obtain additional information directly from the Project team. Furthermore,the potential areas of both loss and/or impact are extensively dealt with throughout the WB EIS andagain in this Supplementary Information document.15.2 Fishermen Numbers15.2.1 Submission #16The submission suggests data about number of fishermen operating in and around GladstoneHarbour is understated.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document15-133

GPC acknowledges that the number of fishermen supplied in the WB EIS is based on Projectconsultation, and not verified against any other source. Prior to any compensatory measure, a rigorousidentification of all potentially affected stakeholders will be undertaken, in conjunction with governmentand industry.15.3 Social Impact Assessment and Significance Ratings15.3.1 Submission #3Submission #3 questions whether the spatial extent of the “loss of natural and recreational areas”impact should be defined as “site”. Council argues the spatial extent should be defined as, at least,“local”.GPC acknowledges that the physical impact of loss of natural and recreational areas will affect a largerarea than only the dredged channels and the Reclamation Area. GPC also acknowledges that peopleresiding throughout the local study area use the harbour and surrounding areas for recreation. GPCconcurs with councils comment.Submission #3 questions whether the “mitigatory potential” rating for the impacts “loss of natural andrecreational areas” and “reduced viability of commercial fishing” are adequate. Council suggests theProject proponent and the state have responsibility for mitigating negative impacts.GPC acknowledges its responsibility in managing social impacts arising from the Project. GPC iscommitted to working with council to identify opportunities to alleviate the loss of natural and recreationalareas, which will include provision of an additional boat ramp, should that be preferred by the community.15.4 Indigenous Employment15.4.1 Submission #18The submission suggests the proponent should, although it is not compulsory, attempt to comply witha 20% indigenous employment target.Given the specialised nature of the dredging works, and the use of international dredging contractors,GPC unfortunately concludes that the opportunities for targeted employment programs are limited. GPCundertakes to include as a contract assessment criteria an allowance for the tenderers’ demonstratedcommitment to indigenous employment.15.5 Compensation to Commercial Fishermen15.5.1 Submissions #3, #6, #16 and #18Refer to Section 12.2 for details.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document15-134

15.6 Recreational Access and Exclusion Zones15.6.1 Submission #3Submission #3 suggests recreational offsets in the form of a boat ramp, and provision of areas for offbankor equivalent fishing. It also mentions the existence of an “unofficial” but utilised boat ramp,which has not been identified in the EIS.GPC undertakes to provide enhanced access for recreational fishermen in the Western Basin region. Itis proposed to provide a sheltered boat ramp for this purpose. Once approved and released, the offsetpackage will provide additional details. Access to bund walls for fishing is to be further discussed.The works will not affect the “unofficial” boat ramp, as the western wall to the Reclamation Area isproposed to be nominally 40 m clear of the mangrove line.15.6.2 Submissions #3, #11, #12 and #15Submission #15 asks whether the eastern channel passage to the Narrows will be blocked by a jetty.Clarify extent to which adjacent areas will be restricted for recreational and professional fishing or anyother activities that may be affected.Clarify why recreational or any other activities will be restricted and for how long.Explain how uses will be reduced, particularly for recreational and commercial fishing and how portfacilities will impact their function.The Eastern Channel passage will remain open to boats if APLNG option 2A is accepted. Access to TheNarrow and Grahams Creek will remain open at all times. It is not the intention of GPC to prevent accessto these areas.Plan 906-0049 Proposed Maritime Exclusion Zones (Figure 15-1) was developed primarily for theWestern Basin Development, and provides details of exclusion zones adjacent to the proposedreclamation. It should be noted that exclusion zones associated with the various wharf jetties from theproposed reclamation will also apply.GPC retains a strong awareness of the fundamental importance of access to the waterways of theharbour to the Gladstone community. GPC undertakes to consult with GRC and the GPC communityworking group in regard to the provision of future community facilities within the port, with a view toimprove access to the Western Basin area.15.6.3 Submission #3Loss of public access for recreational and commercial boating and fishing (including existing"unofficial" boat ramp at western perimeter of reclamation), loss of linkage to the Narrows, loss ofnatural value associated with dredging and reclamation warrants greater consideration of mitigationmeasures. Consider enhanced mitigation / compensation measures for social impacts.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document15-135

Environmental offsets need to be locally based and not simply payment to State's consolidatedrevenue. Include recreational offsets, e.g. provision of all tide access boat ramp, boating facilitiesetc., and monetary compensation for loss of productive fishing areas. Consider enhanced local offsetspackage for loss of commercial and recreational opportunities.Previous responses have confirmed that:Alternate boat ramp facilities will be provided;Access to The Narrows will remain; andOngoing discussions will be held with the fishing industry.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document15-136

16. Bund ConstructionGPC requires the option of constructing the bund 24 hour a day, seven days a week (24/7) for reasons ofconstruction timing and efficiency. Whilst the WB EIS did not specify bund construction hours of work,the potential to adopt a higher construction rate that would be available using GPC’s fleet of trucks wasproposed in Section 2.3.4 of the WB EIS. This portion of text is reproduced below.Construction Rate and Timing (Section 2.3.4 of the WB EIS)The rate at which the bund wall is required to be constructed will depend on the timing and size of thedredging programs that will fill the reclamation. It is likely that the entire bund wall may need to becompleted in one construction program, equating to a rate of approximately 1.8 million m 3 /year. If thebund is only required to be constructed at a rate that allows for the disposal of maintenance dredgingmaterial at approximately 200,000 m 3 /year and minor capital dredging projects, GPC would use theirexisting fleet of trucks to undertake construction at a rate of approximately 400,000 m 3 /year for a numberof years. However, it is most likely that a higher construction rate will be required to support the proposedLNG developments.Additionally, a control strategy (outlined in the EMP of the WB EIS) to avoid impacts on marine faunafrom light spill from construction works was “no night time bund construction”. This control strategy wouldno longer be available under the proposed variation.Further investigation of proposed construction options and schedules has identified that a 24/7construction schedule would deliver significant gains in transport efficiency and a reduction in the overallconstruction time-frame. This would also enable GPC to commence dredging earlier to meet theschedules of LNG gas proponents.16.1 Description of Proposed 24/7 WorksThe major difference between the non-night time construction and the 24/7 scenario would be the use oflighting at night, and additional noise at night. 24/7 lighting and noise from construction would eliminatethe ‘rest’ period that is otherwise permitted with day time restricted construction.The dozers pushing the rock material over the edge will be the major source of noise, as well as thereversing alarms of trucks. Rubber-tyred equipment is not favoured due to high maintenance costs, butmay be used to minimise potential noise impacts. See 16.1.1 for potential noise impacts and proposedmitigation and management measures.The latest haul route for the off-road trucks is shown in Figure 16-1. The focus on potential impacts froma 24/7 bund construction regime is on the Reclamation Area, and not the haul route. However, the haulroute is being assessed under a separate approval process.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-138

057/CP902700400137/FTY18311/MPH3533510001400CT 1385.8691200TC 2177.361CT 2001.570TC 1873.707160020001800TC 1249.6662200CT 2286.800HAUL ROADCONTROL LINETC 2476.434240052/DS66526002800CT 2687.8891/RP6089782/RP608978TC 3084.37930003200FOREST ROAD102/SP10892632/DS469TC 3454.3423400CT 3290.970CT 3716.8093800TC 3877.330CT 3932.12636004000TC 4090.3544200CT 4213.970EXISTING ROAD4400TARGINNIE LANDING ROADTC 4579.1774600CT 4644.0364800TC 4831.626HAUL ROAD CONTROL LINE SETOUTPT CHAINAGE EASTING NORTHING LEVEL BEARING RAD/SPIRAL A.LENGTH D.ANGLE0.000 310483.823 7365787.187 39.253 45°17'54"200.000 310625.978 7365927.870 35.732 45°17'54"TC 255.268 310665.262 7365966.746 35.080 45°17'54"IP2 322.073 310714.594 7366015.567 -200.000 -133.610 38°16'36"CT 388.879 310723.079 7366084.453 34.118 7°01'19"400.000 310724.439 7366095.491 34.062 7°01'19"600.000 310748.888 7366293.991 33.062 7°01'19"800.000 310773.338 7366492.491 32.647 7°01'19"1000.000 310797.787 7366690.990 30.713 7°01'19"1200.000 310822.237 7366889.490 34.065 7°01'19"TC 1249.666 310828.309 7366938.784 36.493 7°01'19"IP3 1317.767 310836.971 7367009.114 -200.000 -136.202 39°01'09"CT 1385.869 310799.423 7367069.209 40.618 328°00'10"1400.000 310791.936 7367081.194 40.834 328°00'10"1600.000 310685.960 7367250.809 39.812 328°00'10"1800.000 310579.984 7367420.423 39.341 328°00'10"TC 1873.707 310540.928 7367482.932 39.799 328°00'10"IP4 1937.639 310507.006 7367537.225 1000.000 127.864 7°19'34"2000.000 310480.941 7367593.974 40.557 335°14'20"CT 2001.570 310480.284 7367595.400 40.561 335°19'44"TC 2177.361 310406.907 7367755.145 37.091 335°19'44"2200.000 310400.307 7367776.729 36.083 350°40'02"IP5 2232.081 310380.236 7367813.208 84.566 109.439 74°08'54"CT 2286.800 310428.807 7367854.725 34.280 49°28'37"2400.000 310514.855 7367928.277 33.527 49°28'37"TC 2476.434 310572.956 7367977.941 31.999 49°28'37"IP6 2582.162 310655.024 7368048.091 -425.000 -211.455 28°30'25"2600.000 310653.976 7368070.660 29.528 32°49'07"CT 2687.889 310693.662 7368148.904 27.770 20°58'12"2800.000 310733.784 7368253.589 25.528 20°58'12"3000.000 310805.360 7368440.343 21.955 20°58'12"TC 3084.379 310835.557 7368519.133 20.134 20°58'12"IP7 3187.675 310876.205 7368625.190 200.000 206.591 59°11'02"3200.000 310905.016 7368609.551 17.510 54°05'34"CT 3290.970 310988.110 7368644.612 15.652 80°09'14"3400.000 311095.534 7368663.256 12.576 80°09'14"TC 3454.342 311149.076 7368672.549 10.603 80°09'14"IP8 3585.575 311291.726 7368697.307 250.000 262.467 60°09'11"3600.000 311291.659 7368655.433 6.157 113°32'10"CT 3716.809 311384.196 7368585.900 4.125 140°18'24"3800.000 311437.328 7368521.887 3.509 140°18'24"TC 3877.330 311486.717 7368462.383 3.558 140°18'24"IP9 3904.728 311504.243 7368441.268 -400.000 -54.796 7°50'56"CT 3932.126 311524.488 7368422.744 3.954 132°27'28"4000.000 311574.564 7368376.926 4.861 132°27'28"TC 4090.354 311641.225 7368315.933 6.723 132°27'28"IP10 4152.162 311686.883 7368274.156 -1000.000 -123.616 7°04'58"4200.000 311726.010 7368246.495 6.767 126°10'32"CT 4213.970 311737.344 7368238.328 6.557 125°22'31"4400.000 311889.029 7368130.630 4.038 125°22'31"TC 4579.177 312035.126 7368026.900 4.153 125°22'31"4600.000 312051.946 7368014.625 4.059 126°51'60"IP11 4611.606 312061.583 7368008.115 800.000 64.859 4°38'43"CT 4644.036 312086.432 7367987.250 3.839 130°01'13"4800.000 312205.871 7367886.955 3.477 130°01'13"TC 4831.630 312230.094 7367866.616 3.636 130°01'13"IP12 4913.927 312300.309 7367807.655 -150.000 -164.594 62°52'13"CT 4996.224 312384.801 7367843.259 4.066 67°09'10"5000.000 312388.281 7367844.729 4.048 67°09'10"5200.000 312572.590 7367922.385 3.462 67°09'10"5400.000 312756.898 7368000.0040 4.063 67°09'10"5600.000 312941.207 7368077.695 3.461 67°09'10"5800.000 313125.516 7368155.351 4.459 67°09'10"6000.000 313309.824 7368233.006 3.663 67°09'10"6199.359 313493.519 7368310.460 4.30 67°09'10"600800LANDING ROAD104/SP155862CT 4996.2135000STAGE 2STAGE 15200540056005800TC 255.2686000200CT 388.879OBODIN ROADSERRANT ROAD1/SP108922502/SP2072986199.359GLADSTONE PORTS CORPORATIONDESIGN AND CONSTRUCTION OF BUND ANDASSOCIATED HAUL ROAD AND QUARRYHAUL ROADA29.03.1016-1

16.1.1 Existing Light EnvironmentThere are a number of existing light sources near the proposed bund. These include:A cement plant adjacent with a tower extending approximately 100 m to the air. The plant and towercurrently have lighting for a 24/7 operation;Safety/security lighting on the existing Fisherman’s Landing wharf and conveyor out to the wharf; andReflected light across the waters of the harbour from Gladstone and the RG Tanna Coal terminal(24/7 coal operations).The lighting from the 24/7 bund construction operation will incrementally increase the overall lightingwithin the harbour. However, construction lighting levels will be less than when the area is ultimatelydeveloped.16.1.2 Existing Noise EnvironmentAs a major industrial port on Australia’s east coast, Gladstone harbour has a baseline noise value that iscontributed by shipping, handling of commodities, large and small vessel traffic and other minorconstruction activities along the Gladstone foreshore.16.1.3 Proposed LightingLighting requirement for night works are likely to consist of the following:Up to three mobile lighting towers (4-6 lights each tower) at each of the work faces; andOne mobile tower at each 90 0 turn/intersection (e.g. at the turn from the existing bund onto the newbund).The lights will be directed down to minimise light spill into the water or adjacent mangrove areas. SeeSections 16.3, 16.4, and 16.5 for details on potential impacts and proposed mitigation and managementmeasures in regard to lighting.16.2 Noise16.2.1 Potential ImpactsNoise modelling results presented in Chapter 10 of the WB EIS indicated noise impacts from theReclamation Area would be in the order of 25dB(A) at the nearest residential receiver, which is locatedon Fisherman’s Road, approximately 2,500 m from the construction site. At other residential receivers,noise impacts are anticipated to be 20dB(A) or less. The above noise impacts are based on conservativeassumptions and are well below the Project-specific noise targets.With regard to noise, construction of the bund will essentially involve dozers on the construction facesand haul trucks bringing material to site. It is understood that 24/7 construction would involveapproximately 10 haul truck movements per hour (based on a fleet of five-six CAT 777 trucks). Additionalnoise modelling was therefore conducted for the following scenarios, using the noise model developedas part of the WB EIS preparation:42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-140

Scenario 1: Dozers and trucks tipping at Reclamation Area.Scenario 2: Dozers at Reclamation Area and trucks on haul road in the vicinity of the quarry (closestpoint to receiver R1, Fisherman’s Road).Table 16-1 summarises the results at the nearest receivers (as identified in the WB EIS). Figure 16-2shows the location of the nearest receivers.Table 16-1 24/7 bund construction noise impactsLocationPredicted Noise Impacts dB(A)Scenario 1 Scenario 2Receiver 01 17 dB(A) 18 dB(A)Receiver 02 20 dB(A) 23 dB(A)Receiver 03 26 dB(A) 34 dB(A)As shown above, site works are expected to meet the night-time targets outlined in Table 10-4 of the WBEIS (reproduced here as Table 16-2). The sleep disturbance 45dB(A) L max noise goal is also expected tobe met.Commonly, the most irritating noise sources on construction sites at night-time are reversing alarms dueto their intermittency, randomness, loudness and pitch. It is recommended that controls be in place tominimise impacts from reverse beepers should they be identified as an issue during the works.Table 16-2 Project specific noise goals dB(A) from WB EISTime PeriodLocation Construction activity Day(7am to 6pm)Evening(6pm to 10pm)Night(10pm to 7am)R01 Reclamation 41 29 23R02 Reclamation 45 45 47R03 Reclamation 48 43 38R04 Dredging 48 43 38R05 Dredging 48 43 38R06 Dredging 48 43 38R07 Dredging 48 43 38R08 Dredging 48 43 38R09 Dredging 48 43 38R10 Dredging 48 43 3842/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-141

307,000308,000309,000310,000311,000312,000313,000314,000315,000316,000317,000318,000319,000320,000321,000322,000323,000324,000325,000326,0007,372,000Curtis Island7,372,0007,371,000&

16.2.2 Mitigation and Management MeasuresAlthough night-time works are not anticipated to generate appreciable noise impacts, it is recommendedthat reasonable and practical measures be implemented to minimise the risks of noise disturbances tothe local community. Table 16-3 outlines standard noise and vibration management controls.Table 16-3 Standard construction noise and vibration management controlsEnvironmental Management ControlsAll construction vehicles and machinery should be fitted with manufacturer supplied noise suppression devicesmaintained in accordance with manufacturers’ guidelines.The Construction Site Manager should provide a community liaison phone number and permanent site contactso that noise and/or vibration related complaints, if any, can be received and addressed in a timely manner.All site workers (including subcontractors and temporary workforce) should be informed of the potential fornoise impacts upon local residents and encouraged to take all practical and reasonable measures to minimisenoise during the course of their activities.Work methods should be reviewed with a preference for quieter and non-vibration generating methodswherever possible. This is particularly relevant for any out-of-hours and night-time activities.All plant on site should be operated in accordance with the manufacturer’s instructions.Fixed equipment (pumps, generators, compressors) should be located as far as possible from the nearestresidences.All pneumatic tools operated near a residential area must be fitted with an effective silencer on their airexhaust port.In case of a complaint, the following should be undertaken: Noise monitoring and reporting. Implementation of the corrective actions identified in the monitoring report. Fitting of non-tonal reversing alarms to relevant plant if this is identified as an issue.16.2.3 Schedule 12 of Western Basin Dredging and Disposal EMPThe noise and vibration controls outlined in Schedule 12 of the WB EIS Draft Environment ManagementPlan (EMP) should be included in the final EMP to include a reference to the mitigation measuresoutlined in Table 16-3.16.3 TrafficThe 24/7 operation reflects the high haul rate option referenced in Section 2.3.4 of the WB EIS. Thisoption will use an off-road haul route and mine haul vehicles, thereby removing bulk haulage of quarrymaterial on Council controlled road infrastructure. The haul route was the subject of a Haul RouteOptions Study which was conducted for the WB EIS (of which an extract of the study can be found asAppendix J).42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-143

The haul route project is currently subject to the design and documentation process, in preparation forrelease for Tender to contractors. The haul route alignment is shown in Figure 16-1. The haul route willbe subject to further refinement by the appointed Contractor with respect to profile, drainage structuresand traffic control, as the alignment is generally fixed. Preliminary approval has been reached with theaffected land owners along the route and agreements being negotiated for the use of the land for thehaul route. Approvals required for the haul route lie outside of the WB EIS process and are subject to aconcurrent process.The night construction on the bund will require additional measures to be put in place to minimise the riskto plant operators and haulage vehicles. These measures will be dependant on the Contractor selectedand may include the provision of personnel with radio communication to monitor/instruct vehicles on thebund, at the dump face or in turning areas.The 24/7 operation of the haul route and bund construction will not have any significant impacts on therail network, product spill, existing port, State controlled roads, dredging or airports.16.3.1 Potential Lighting ImpactsLighting will need to be provided along the haul route for 24/7 operation. It is likely that temporary lightingtowers will be provided at all changes in direction, intersections, major creek crossings and intervalsalong the Haul Route to highlight hazards. Lighting would be directionally controlled so as to minimisethe light spill that would cause nuisance to residents, motorists and other users of adjacent land. Acontact point would be established by the Contractor to record any lighting nuisance and the measurestaken to avert the light.Similarly, lighting is likely to be provided along the bunds at changes of directions, turn around points andthe working face in order to provide safe working environment. Lighting will be directional and located soas to minimise attraction or disturbance of marine megafauna and wading/migratory bird species.A significant bund at the waters edge to prevent vehicles running straight into the harbour will cut straylight from reaching across the harbour. Smaller safety bunds may be built either side of the bund toprovide safe operation of the vehicles. Trucks from the end of the existing reclamation will be eitherpointing north or west into the mangroves as they reach the dump point and then depart. The light wouldonly be present for a short time and moving and changing direction most of the time, limiting the affect onmarine life.Refer to Sections 16.4, and 16.5 for more details on potential fauna impacts and proposed mitigation andmanagement measures.16.3.2 Traffic Potential ImpactsThe high rate haulage campaign is expected to take 12-18 months. Fleet simulations undertaken byGHD have identified CAT 777 or equivalent mine haul vehicles as the most efficient for haulageoperations based on one shift per day. On this basis, a fleet of twelve CAT 777s would be needed toundertake the haulage in this 12-18 month period. As timelines may need to be shortened to meet thedredging timelines, 24/7 operation must therefore be considered. The longer operating hours proposedwould allow better utilisation of machinery for less capital outlay, which for the haul route equipmentalone potentially reduces in excess of $20M. Depending on the plant available to the appointed42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-144

Contractor, the actual equipment operated during construction may be different to that found mostefficient by the fleet simulation,Initial results of Talpac fleet simulations for 24/7 operation has indicated that the number of Cat 777 haultrucks will be reduced from 12 (under the one shift a day, five day/week regime) to six, as the haulage isspread over a 24 hour period of the day but over the same 18 month period. This will result in two shiftsof workers, and machinery about half the size of that originally estimated. For the haulage work, this redistributesthe number of peak hour trips to approximately half the number of vehicles in a bi-directionalflow instead of a unidirectional pattern, hence the impacts on the roads and intersections to the site willbe significantly less.16.3.3 Potential Risks and Mitigation and Management MeasuresWhilst the WB EIS excludes the haul road, and approvals are being dealt with in a separate process,some comments are offered here.A risk with the operation of the haul route is the significant difference in size between what is potentially a160 tonne mine haul vehicle 7 m wide, and road registered vehicles or trail bikes trespassing on the haulroute. Other risks include the potential for accidents involving the trucks at night, an uneven bundsurface, or trucks driving off the bund edge. Schedule 13 (Section 19.3.13 of the WB EIS) should beupdated to include the following control issues to mitigate the various potential risks:During the night, equipment operators are less likely see failures in the bund formation (arising fromdisplacement of the soft mud bottom), and hence regular inspections and controllers would beneeded for night-time operation;Where mine haul vehicles interact with road registered or other traffic, the preferred method ofcontrol is grade separation, as the risk of fatigue created by of the 24/7 operation may cause a fatalaccident. Other manned gate type operations are also being considered which signals stop to eitherthe road or haul traffic;Appropriate lighting to be provided; andThe Contractor will be required to manage fatigue of haul vehicle drivers and traffic controllers on thesite for the haulage operation to avoid collisions.The risk of significant differential bund settlement leading to sudden displacement is considered low. Thiswill be monitored prior to each shift change. The haul route, though not the consideration of the WB EIS,will be exposed to risks with additional measures likely to be provided by the Contractor for 24/7operation as follows:The haul route to exclude all other unauthorised traffic in recreational hours by the construction ofsafety bunds and fencing along both sides of the route to exclude the public and trail bikes; andThe longer operation of the haul route means that the Contractor is likely to provide greater securitypatrols to regularly monitor compliance with exclusion of the public from the haul route.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-145

16.3.4 Safety ConsiderationsDisplacement of Mud below Core FillThe core fill will be dumped after the truck has reversed on the bund at approx the +5.5 m level (LAT)and later to +7.0 m (LAT). The trucks will not travel to the face of dumping, as they will dump on thebund with a dozer to spread the core out and further into the water. The bulk of the settlement and wavecreation (expected to be a maximum of 1 m height) is likely to occur immediately. The fact that the trucksare constantly traversing on the bund will lead to settlements occurring early during construction.Monitoring by survey, and visual monitoring each day are likely mitigation measures.Night-time WorkThe night-time work will have reduced visibility, and lights will be required at strategic locations. All truckand dozer operators should have 2-way radios, and be in constant communication. An additionalavailable mitigation measure is the utilisation of a dedicated person to be at the bund dumping face.16.4 Terrestrial FaunaWhile the proposed haul road passes close to several existing industries operating on a 24/7 basis, theproposed construction of the Western Basin bund wall, through operation of the associated haul road, islikely to result in additional impacts on terrestrial fauna. These impacts will be short-term as a result ofthe construction activities being conducted and are restricted to the period required to conduct theseactivities. Construction of the bund wall will require deposition of rock material directly onto the marinesubstrate to enclose the area. This enclosure will then be reclaimed using dredged material.16.4.1 Potential ImpactsThe potential impacts to terrestrial fauna associated with the 24/7 construction of the bund area include:Disruption to wildlife behaviour as a result of light, noise and vibration disturbances from constructionactivities; andDirect mortality to fauna during construction.Disruption to Wildlife BehaviourThe intertidal habitat in close proximity to the haul road and Reclamation Area is not regarded as theoverly important area for wading and shorebirds. However, some migratory shorebirds or migratoryterrestrial bird species may periodically utilise the intertidal areas at Fisherman’s Landing. The intertidalmudflats on the seaward side of the mangrove vegetation in the larger Western Basin area providesimportant feeding habitat for some shorebirds. This is more so towards Friend Point, to the north of theWestern Basin Reclamation Area, and less so towards the existing Fisherman’s Landing facility.Similarly, the mangrove areas towards the existing Fisherman’s Landing facility do not provide highquality roosting habitat. As a consequence, it is thought that it is unlikely that migratory shorebirds ormigratory terrestrial bird species would extensively utilise these areas for roosting or feeding when moreoptimal habitat exist to the north.Light, noise and vibration from activities associated with the establishment and infilling of theReclamation Area, for example 24/7 operation of haul vehicles, heavy earth-moving machinery and42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-146

deposition of large grade rock material for the bund wall, may disturb migratory shorebirds roosting innearby mangroves or feeding on tidal flats in close proximity to construction activities.The proposed development area is currently subject to industrial activities which operate 24/7 (e.g.storing and haulage of plant for the Rio Tinto Yarwun2 project, QER project and Cement Australiaoperations). It is expected that the combined impacts of noise and vibration are expected to be localised,with animals further from the bund construction area minimally affected or able to habituate.Direct Mortality of FaunaAny large construction activity in a natural environment has the potential to cause fauna injury ormortality. The continuous activity of heavy vehicles associated with 24/7 construction has potential toincrease the incidence of terrestrial fauna mortality via collision. However, as the surrounding land usesalready generate heavy vehicle traffic, this impact is not considered to be substantial, and appropriatemeasures can be employed to minimise this risk.16.4.2 Mitigation and Management MeasuresMost impacts on fauna can be avoided by implementing appropriate mitigation and managementmeasures if 24/7 construction was to occur. The following mitigation measures may be implemented toreduce the impacts of the risks identified above:Employ directional lighting pointed towards the Reclamation Area and away from surroundinghabitat;Use glare guards in the vicinity of the important shorebird habitat to the northwest of bundconstruction area;Educate employees of environmental responsibilities during inductions;Additional mitigation measures (e.g. speed limits, fencing) will be conditioned throughout the haul roadapproval process.16.4.3 WB EIS Risk RegisterDisturbance to wildlife behaviour (mainly birds and bats) was assessed as being a medium risk due tonoise, light and vibration with the potential to disturb EPBC listed migratory shorebird species during acritical phase of life-cycle, e.g. roosting, or limit access to food resources. The WB EIS Risk Register hasbeen updated to include reference to the mitigation measures outlined in Section 16.4.2 (Table 16-4).42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-147

Table 16-4 Updated risk assessment for terrestrial flora and faunaActivityDescriptionPotential Impactsand theirConsequencesPreliminaryRiskAssessment(C, L) ScoreAdditional Control StrategyResidual Riskwith ControlStrategiesAdopted(C, L) ScoreConstructionPhase -Building ofbund andreclamationDisturbance to wildlife(mainly birds andbats) behaviour dueto noise, light andvibration. Potential todisturb EPBC listedmigratory shorebirdspecies during criticalphase of life-cycle,e.g. roosting, or limitaccess to foodresources.(3, 5)HighEmploy directional lighting pointedtowards Project area and away fromsurrounding habitat.Use low wattage lights and glare guardsin vicinity of the important shorebirdhabitat in the north-west of the Projectarea.Ensure plant and equipment aremaintained.Monitor abundance and diversity ofavifauna species for signs of impact toallow for adaptive management wherepossible.(3, 1)LowDirect mortality offlora and faunaassociated withvehicular traffic anddeposition of largerock material.(3, 1)LowEducate employees of environmentalresponsibilities during inductions.Establish appropriate speed-limits torestrict incidence of wildlife road-kill.Refer to Marine Megafauna and MarineEcology technical reports appended tothe WB EIS.(2, 1)LowIndirect degradationof habitats due topollution, weed andpest species, and acidsulphate soils. (3, 4)MediumRefer to Acid Sulphate Soils technicalreport.Install appropriate rubbish disposalfacilities on site (including recyclingoption).Include a weed and pest managementplan as part of the EMP for the Project.Management plan will includeprocedures for managing the spreadingof weeds from construction vehicles.Refer to AcidSulphate Soilstechnicalreport.16.5 Marine Fauna16.5.1 Potential ImpactsA 24/7 construction program is likely to have an incremental impact on the marine ecological values ofthe Project Area. These impacts are associated with lighting and water quality effects, whereby thepotential impacts of increased construction hours per day are amplified due to the lack of a‘rest/recovery’ period between construction activities.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-148

Lighting ImpactsLighting impacts are likely to change the use of the immediate marine area by fauna species where lightspill is evident. Potential impacts may include aggregation to the light source by some invertebrate andfish species, which may consequently attract dolphin species. Alternatively the light may displace speciessuch as turtle and dugong. Industrial lighting impacts are present throughout the Gladstone foreshoreregion. Marine fauna currently coexist with extensive lighting of construction and operational sites withinGladstone and with commercial fishing vessels in the Gladstone Harbour with no observed detrimentaleffects noted. Reductions to lighting impacts from the Project will be incorporated where appropriate.Noise ImpactsThe underwater noise generated by the dumping of rock to create the bund wall will likely be sufficient involume to displace mobile marine fauna from the immediate Project site and adjacent waters. This soundis unquantified however, it will likely vary with the bund construction stages and the contact of materialsfor the armour rock.Water Quality ImpactsWater quality impacts associated with construction of the bund include the generation of a turbid plumethrough the placement of construction material on the seafloor. Depending on the type of constructionmaterial, there may also be the potential for fine terrestrial sediments associated with the quarried rock tobe introduced to the marine area during the placement activities. The terrestrial fine sediments are likelyto be minimal, as the rock material is to be screened at the quarry. The persistence of turbid plumesdepends on a number of factors including the grain size of the sediment in suspension, and the longevityof the disturbance that caused the plume.The lack of a rest/recovery period has implications for both the benthic communities that may beimpacted by the plume (via effects of shading and/or burial), and communities that utilise these areas,including marine megafauna. It is likely that the areas that will be impacted by the plume will suffer from achronic loss of light for the entire construction period. The area impacted wll be localised and will movewith the bund front.While these habitats are predicted to recover following cessation of construction and dredging works, thedegree of impact will influence the rate of recovery and under a press impact scenario recovery ofcommunities may take a number of years.16.5.2 Mitigation and Management MeasuresMost impacts on fauna can be avoided by implementing appropriate mitigation and managementmeasures if 24/7 construction was to occur. The following mitigation measures may be implemented toreduce the impacts of the risks identified above:Employ directional lighting (with shields) pointed towards the bund construction area and away fromsurrounding marine and mangrove habitats;Lower the height of lighting where possible;Use sensor/security lighting where appropriate;Use low pressure sodium vapour lighting in place of metal halide lamps;42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-149

Use glare guards in the vicinity of the important megafauna habitats to the northwest of the bundconstruction area; andEducate employees of environmental responsibilities during inductions.16.5.3 WB EIS Risk RegisterDisturbance to marine flora and fauna (seagrasses, marine megafauna etc) under a 24/7 constructionscenario has been assessed for each of the impacts likely to occur (as identified above). The WB EISRisk Register has been updated to include a reference to these risks and mitigation measures outlined inthis section (Table 16-5).Table 16-5 Updated risk assessment for marine flora and faunaActivityDescriptionPotential Impacts andtheir ConsequencesPreliminaryRiskAssessment(C, L) ScoreAdditional Control StrategyResidual Riskwith ControlStrategiesAdopted(C, L) ScoreConstruction Phase (24 hours/ 7 days)Building ofBundRemoval or damage tohabitat (lighting and noiseconsidered). Seagrassspecies, algae,megafauna andmacrobenthic species,including fish and crabspecies removed fromfootprint and many likelydisplaced duringconstruction. Reductionin biodiversity.(2, 5)MediumNo ability to control impact. Habitatand communities representedelsewhere in region except forseagrass complex. Shrouds overconstruction lighting should beused to reduce light spill into themarine environment. Additionallighting measures outlined below.Offsets, as addressed under GPCoffsets strategy for whole of portactivities, to be implemented.(2, 5) MediumConstruction lighting forsafe work practiceschanging the local marinehabitat. Potentiallyattractive to somespecies such asinvertebrates, fish,dolphins. Potentiallydisplacing other speciessuch as marine turtle anddugong.(2, 5)MediumLighting is required for safeconstruction practices. Potentialimpact to marine environment andbiodiversity can be reduced byhaving shrouds to direct lightingaway from marine environment andusing reduced wattage lighting toreduce light spill and, therefore,potential attraction or displacementeffects. Additional lightingmitigation measures include:(2, 5) MediumLower the height of lightingwhere possible;Use sensor/security lightingwhere appropriate;Use low pressure sodiumvapour lighting in place of metalhalide lamps;Use glare guards in the vicinity42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-150

Activity Potential Impacts and Preliminary Additional Control Strategy Residual RiskDescription their Consequences RiskAssessment(C, L) Scorewith ControlStrategiesAdopted(C, L) Scoreof the important megafaunahabitats to the northwest of thebund construction area; andEducate employees ofenvironmental responsibilitiesduring inductions.Removal or damage tohigh conservation valuemegafauna habitat.Seagrass species, algae,and soft sedimentinvertebrates.Water quality impacts(including from alteredsiltation/sedimentationregimes), persistentplume that may havepotential follow on affectsfor trophic groupsincluding seagrasses andtheir associated species,including marine turtles,dugong and dolphins.(4, 5) High No ability to control impact. Habitatis identified as high conservationvalue to dugong and recorded asimportant habitat for marine turtlesand dolphins also. Offsets to beimplemented for habitat losses.(4, 5) High No ability to control impact. Siltcurtains inappropriate given highflow environment. Habitat andcommunities representedelsewhere in region except forseagrass complex. Implementoffsets for habitat losses. Expectedto be minimal impacts.Monitor adjacent sensitiveecosystem receptors according toDredge Management Program(DMP) and implement trigger levelsat selected habitat sites wheremajor impact is not predicted.Seasonality (wet/dry) is also likelyto influence the potential impact toseagrass and habitats resilience.(4, 5) High(4, 5) High42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document16-151

17. Management Measures17.1 Dredge Management Submissions17.1.1 Request for Future Detailed Dredge Management PlanSubmission #2A detailed plan for the management of disposal of dredge spoil in the reclamation area toaccommodate the total volume of spoil and for all rates of dredging (solids and water), spoil types,and potential acid sulphate soils under all weather conditions needs to be defined in a managementplan.A detailed dredge management plan (DMP) will be prepared following awarding of the dredging tender.Refer also to Section 17.2 for response.17.1.2 Liaison with Regional Harbour MasterSubmission #1 The proponent should liaise with the Harbour Master (Gladstone) to ensure there is consistencybetween the dredging requirements being quoted in all EIS’s for the expansion of the Port ofGladstone.As indicated in Chapter 4, this liaison will be carried out.17.1.3 Dredge SchedulingSubmission #13QGC recommend that the dredge scheduling occurs - whether concurrent or sequential -so that theoverall intensity and duration minimises impacts to below a predetermined thresholds ofunacceptable impacts.Dredge scheduling is seen as a highly important activity, and is being addressed by GPC on an ongoingbasis. The initial works for the WB EIS investigated the potential impacts associated with four dredgesoperating simultaneously (as a worst case), with this assumption regularly tested in the ensuing months.Submission #18Develop an appropriate dredge mitigation strategy to ensure that there are not widespread losses ofseagrasses outside of the direct dredge footprint.Hydrodynamic and plume modelling has been undertaken in order to develop an understanding of whichareas outside the direct footprint will be affected. The resultant spatial plume maps provide a strongrelative indication of which options will lead to the highest plume concentrations at key points of interest.The primary measures to minimise excessive seagrass loss are those involving the potentialminimisation of rehandling, utilisation of CSD vessels in shallower waters (i.e. those closest to TheNarrows), and the minimisation of overflow dredging associated with fine sediments.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document17-152

17.2 Dredge Management ReponsesThe preparation of a Dredge Management Plan (DMP) is a standard requirement for all dredgingprojects, with the scale of the Western Basin Dredging and Disposal Project making this of even greaterimportance.The EMP already states that a DMP will be developed, with a number of management measures forachieving improved water quality already nominated in this document. In particular, reference should bemade to the following:ChapterDredge Management Measures Addressed4 Method for placement of material in reclamation.Use of internal bunds and baffles as required.Confirmation that GPC will liaise with the Regional Harbour Master.5 Updated (smaller) estimate of dredge volumes. This has arisen through refinementof the design of channels, swing basins and berths for each proponent. Furtherconsolidation may occur.Revised dredging methodology, with emphasis on reduced rehandling and limiteduse of overflow mode when dredging fine sediments.8 Movement of dredge decant from north-west to north-east corner of ReclamationArea.Reduction from 95 th to 80 th percentile targets in setting WQOs.12 Overview of offsets package. Offset calculations have been based on theassumption of an extensive area of impact. The reality is that whilst the plume mayextend over a broad area during the multiple year duration of the Project, mostareas will not feel a significant increase in turbidity. Hence, by referencing the full“indirect” area of impact, the likely extent of impact in the long term has most likelybeen over estimated.13 Chapter 13 provides an overview of how potential acid sulphate soils (PASS) willbe managed, with the outline of an ASSMP presented as Appendix E to thisdocument.18 Discussion as to the significant potential benefits should rehandling be removed.This can occur if TSHD vessels are able to either pump directly into thereclamation (where clays and silts comprise less than 30% of the total), or utilisethe existing offshore disposal ground (finer materials).The final DMP cannot be developed until the availability of dredgers has been determined through thetendering process and the project dredging scope confirmed. As a programme is identified, theassociated DMP will be developed and approval sought.A DMP has been previously produced for the existing Fisherman’s Landing, and for the upcomingWiggins Island project. Both should form the basis for an enhanced DEMP for the Western Basin Project.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document17-153

Reporting Associated With DMPThe DMP will include contingency measures to allow a range of operational measures to provideflexibility to meet the decant discharge and other specified limits.As part of the application for approval of a DMP, detailed design drawings shall be provided to DERM todemonstrate the system of cells, baffles and weir boxes within the outer bund wall of the ReclamationArea as effectively meeting the limits specified for suspended sediment and turbidity, which accounts forthe specific dredge spoil characteristics.Monitoring will be undertaken, and records kept, of decant water quality at the frequency nominated inthe agreed conditions.DERM will be notified by telephone, email or fax of any exceedence of the agreed objectives/triggercriteria within 24 hours of awareness of an exceedence occurrence.17.3 Monitoring Programs17.3.1 OverviewOngoing monitoring programs are considered of fundamental importance to the harbour, and will need tobe maintained. In addition, additional monitoring will be undertaken before, during, and after anydredging works where material is to be deposited into the reclamation.Preliminary details of the requirements of the monitoring program are provided through Chapters 7 to 10of this Supplementary Information document, and address issues including:Monitoring locations;Types of monitoring to be undertaken; andDuration of monitoring needed.In particular: A detailed discussion with respect to the setting of water quality objectives was provided in Ch 7. Sites suitable for monitoring were presented in Figure 10-01. These included reference sites, habitatmonitoring sites, and dredge plume monitoring sites.17.3.2 Submission #11If full range of sampling is not to be undertaken - has the draft SAP been accepted and approved forimplementation? Provide sampling and sediment analysis information as outlined in an approvedSAPThe Sediment and Analysis Plan (SAP) was included as Appendix A to the Sediment Quality report(issued as Appendix L to the WB EIS). DEWHA reviewed the SAP, with each of their issuessubsequently addressed in Chapter 2 of Appendix L.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document17-154

17.4 Details of Dredge Monitoring Program17.4.1 Proposed ProgramThe DMP will address the most current dredging methodology, as determined through the tenderingprocess. This has continued to evolve in parallel with the WB EIS, with updated information presented inChapter 5 of this document. The DMP will include:Any updates to proposed dredge methodology and dredge volumes (these have been reducing withtime).Type and duration of dredgers (current plan involves primarily use of CSD equipment, with TSHDwhere navigation is to be maintained, or where deeper water exists to allow better access).An estimation of what proportion of material will be disposed of offshore, what proportion pumpeddirectly to the reclamation, and what portion (if any) might require rehandling.A review of the proportion of material comprising clay, silt, sand and gravels.17.4.2 Managing Dredging OperationsSubmission #2 However, as sufficient data are available to allow conditioning of the maximum turbidity in waterdischarged from the reclamation area, it is unclear how the water quality objectives for turbidity couldbe used to manage dredging operations as this would require ecologically significant limits, or triggervalues, to be defined for turbidity in specified areas and to account for natural variations. Suchlimits/trigger values would then need to be linked to changes to dredging activities that would reduceturbidity at the specified locations. The EIS does not contain such detailed management information.If it is proposed to use turbidity monitoring as a means of varying dredging activities in response tospecified limits/trigger level, the EIS needs to state the ecologically significant trigger levels to beadopted at specified locations; the means be which monitoring will be conducted to determinewhether a trigger level has been exceeded under all sea-state conditions during dredging operations;and the actions that must be taken to reduce sediment loading to waters while recognising naturalvariation due to wind, tide and rainfall.The 80 th percentile of representative seagrass bed locations (Middle and Northern Western Basin,Wiggins Island) and the Narrows have water quality objectives that have been developed (refer Chapter8). It is proposed to use the median values of periodically retrieved logger data over the course ofdredging activities as the key statistic. After each logger download, the median will be calculated andcompared to the water quality objective (e.g. baseline 80 th percentile). A tier of responses will be initiatedsuch as:If the median of the data marginally exceeds the site specific water quality objective then theresponse will be to increase the frequency of monitoring and analysis.If exceedances continue to occur then the dredging and decant operations will be modified to yieldcompliance at the site. Operational measures that can be used are summarised in Section 9.1.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document17-155

17.4.3 Commitment to MonitoringSubmission #11There is mention of monitoring, but not when, where or how. Suggested solution is to show GPC’scommitment to monitoring the 10 loggers mentioned in the EIS should be reinstalled in the samelocation (to allow accurate comparison to baseline information gathered) and maintained during andafter completion of work to provide invaluable information of water quality parameter concentrations.This would also provide excellent and accurate information for adaptive management if certainparameters exceed water quality guidelines.A monitoring strategy will be developed as part of the Dredge Management Plan. One element of themonitoring plan will be the deployment of loggers that will be regularly downloaded and analysed. Theseloggers will be placed in key locations within high impact, low to moderate impact and reference sites.The monitoring data will be compared to trigger levels that initiate a range of responses to maintain waterquality at acceptable levels in different regions throughout the Project Area.Ongoing monitoring programs are considered of fundamental importance to the harbour, and will need tobe maintained. Monitoring at a number of sites throughout the harbour has been occurring since theinception of the WB EIS, and is still ongoing. The use of monitoring has allowed a detailed understandingof existing conditions to be gained, Additional monitoring will be undertaken before, during, and after anydredging works.Key issues include:Proposed monitoring locations;The types of monitoring to be undertaken; andDuration of monitoring needed.Figure 10-1 presents suggested indicative sites for monitoring.Sites will serve one of four purposes:Placement at sensitive primary producer habitats within the predicted plume area, in order to identifythe actual indirect impacts of the dredging program. These sites should be selected through theresearch programs to be delivered under the offsets package;Reference locations outside the predicted plume area, which will allow the measurement ofbackground water quality;Sites to allow determination of the spatial decay of the plume; andSites to be located towards the periphery of the predicted plume extent that are also in the vicinity ofenvironmentally sensitive areas. This last group of sites will form the basis for measuringconformance to trigger values.Actual monitoring locations will need to be updated once dredging details are confirmed.The habitat monitoring program will be tied into the dredging program and refined during the planning ofthe dredging activities as part of the DMP. The duration of each of the monitoring stages will be refined inthe DMP.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document17-156

17.4.4 What to MonitorDERM has provided suggested decant trigger values, based on existing 80 th percentile turbidity values.It is proposed that the monitoring at trigger locations would also focus on 80 th percentile criteria. Thetarget would consist of the difference between median and 80 th percentile values taken frommeasurements. Measurements would then occur through the use of automatic (continuous) loggers. Arolling average would be applied, and the 80 th percentile of measurements (and maximums) reported toDERM.It will also be necessary to monitor (or predict) and report on background turbidity. This will necessitateeither or both of the following:Monitoring of relevant (reference) areas unaffected by the plume. This may be difficult given the sizeof the plume, and the change in characteristics of areas such as the Narrows and Pelican Banks incomparison to the locations where dredging is occurring, and where dredge plumes may reach.Utilisation of pre-dredge monitoring at a number of locations to set up a history of turbidity. Thiswould then need to be correlated to conditions (i.e. spring vs. neap tide, different wind and waveconditions, etc) and/or to readings at other sites.17.4.5 How Long?Monitoring will need to commence a minimum of 6 months prior to the commencement of dredging, andshould continue for a period of at least 6 months after dredging. DERM have indicated a desire foraccess to the dataset once the dredging program has been completed.17.4.6 Dealing with ExceedancesA key issue in establishing a monitoring program is the need to have a protocol for dealing withexceedances. This includes not only what actions are necessary (be they notification or response), butalso how to deal with erroneous values.17.4.7 Monitoring of LightSubmission #18Fisheries Queensland would request that an appropriate dredge mitigation strategy be developed toensure that there are not widespread losses of seagrasses outside of the direct dredge footprint.Specific information should be included in the strategy, including: The light requirements andtolerances for the different seagrass species that occur in Gladstone; Good modelling of plumepropagation under different conditions, and, An ability to effectively measure light stress at sub-lethallevel in seagrasses to implement appropriate dredge mitigation during the program.A Dredge Management Plan will be developed that incorporates a Monitoring Plan.Trigger levels in the monitoring plan will trigger responses to exceedances. Light and turbidity loggers willbe deployed at key locations at high, moderate and low impact sites as well as reference sites.Fortnightly data downloads will be analysed against trigger values to determine if light availability issevere (acute) or chronic (sub-lethal) or chronic levels. Information made available by DERM indicate42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document17-157

that 16-30% surface irradiance is required for several species of seagrasses. This information will beused to set the trigger levels in the monitoring plan.17.4.8 Submission # 4NODGDM (2002) was superseded in February 2009 by the NAGD (2009). Any further discussionshould reflect this point.Acknowledged - any reference to NODGDM (2002) rather than NAGD (2009) was an oversight. Futurereferences will refer to NAGD.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document17-158

18. Rehandling and Offshore Disposal Option18.1 OverviewIn response to submissions on the Western Basin Dredging and Disposal Project, GPC is assessing theoption of offshore disposal for a portion of the dredged material. The Port has an existing offshore spoilground (East Banks Sea Disposal site, refer to Figure 18-1 for location). The capacity of the East BanksSea Disposal site was recently reviewed, with the current remaining capacity assessed at approximately15 million m 3 . This option was not included in the WB EIS as the capacity of the spoil ground wasunderstood to be less than 5 Mm 3 and reserved for maintenance works. With confirmation of the offshorespoil ground capacity and the request via public submissions for offshore dredge material disposal to beconsidered, it is now an option being investigated.The most likely scenario would involve the offshore disposal of the majority of material dredged using atrailing suction hopper dredge (TSHD). It is estimated that a volume of the order of 6 to 8 million m 3 couldbe disposed off in this manner.The process proposed would be to seek a new permit for the existing spoil ground (in a separate, butparallel approval process to the EIS). The proposed application to support the Project would be for adisposal volume of the order of 8 million m 3 .Use of the offshore sea disposal ground potentially provides a significant environmental net benefit, asuse of the ground would almost entirely negate the need for rehandling. Rehandling has been predictedto generate a significant turbid plume through the dumping process, and also the subsequent re-dredgingof this material using a CSD. Disposal would be managed so that the dump offshore occurs furthestaway from any environmentally sensitive areas (i.e. the disposal location will vary with the state of thetide and wave effects). The environmental benefit of offshore disposal would be a significant reduction inturbidity within the estuarine environs of the Port of Gladstone. There would be a temporary plume at thespoil ground, the duration of which would be detailed in the sea dumping permit. It is anticipated that aTSHD would remove 5-6 loads per day which translates to a total disposal time at the spoil ground of nomore than 6 hours per 24 hours18.2 Sediment LoadingIf rehandling is not required, then all of the TSHD material would either be pumped directly into theReclamation Area (minimal proportion) or disposed offshore (bulk of TSHD material). It has beenassumed that offshore disposal would increase the cycle time from 3 hours to 4.5 hours. Accordingly,the revised total source flux rates for each scenario are summarised in Table 18-1.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document18-159

310,000315,000320,000325,000330,000335,000340,000345,000350,000355,000360,000365,0007,375,000THE NARROWSKANGAROOISLANDLairdPointGRAHAM CREEK7,375,000FriendPoint!( TOWNSVILLE7,370,000WESTERNBASINQueenslandROCKHAMPTONGLADSTONE!( !(!(7,370,000PILOTAGE AREAFISHERMAN'SLANDINGTarginie ChannelBoatshed PointHamilton PointBRISBANEPORT LIMIT7,365,000PORT CURTIS7,365,000Clinton ChannelRG TANNACOALTERMINALAuckland ChannelGBRMP LIMIT7,355,000CA L LIOPE RIVERSOUTH TREES INLETGatcombe ChannelCanoe PointGatcombe HeadGolding CuttingEAST BANKSSEA DISPOSALSITEBoyne CuttingWild Cattle CuttingPROHIBITEDANCHORAGESPOIL GROUND7,355,0007,350,000GBR COAST MARINE PARK LIMITGBRMP LIMIT7,350,0007,360,0007,360,000BOYNE RIVER7,345,000Colosseum Inlet7,345,000Rodds Bay310,000315,000320,000325,000330,000335,000340,000345,000350,000355,000360,000365,0001:150,0000 1 2 3 4 5Kilometres (at A3)Map Projection: Transverse MercatorHorizontal Datum: Geocentric Datum of Australia 1994Grid: Map Grid of Australia, Zone 56oLEGENDSpoil GroundPort LimitsPilotage AreaFisherman's Landing Northern ExpansionWestern Basin Reclamation AreaExisting Channels, Swing Basins and BerthsCoastal Marine ParkDugong Protection Area - Rodds Bay (Type B)Fish Habitat AreaG:\42\15386\GIS\WesternBasinSupplementaryEIS\Mxd\4215386-56_017.mxd© 2009. While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd, GPC, DPI&F, GBRMPA, EPA and GA make no representations or warranties about its accuracy, completeness or suitability for any particular purpose. GHD Pty Ltd, GPC, DPI&F, GBRMPA, EPA cannot accept liability of anykind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data Sources: Port Facilities - Gladstone Ports Corporation Oct 2008. 250K Topo Data - ©Commonwealth of Australia (Geoscience Australia) 2006. Fish Habitat Area, Dugong Protection Area - ©State of Queensland (Department of Primary Industries & Fisheries).GBRMPA data ©Commonwealth of Australia (Great Barrier Reef Marine Park Authority) 2008. State Marine Parks - ©State of Queensland (Environmental Protection Agency) 2008. Created by: T HatfieldGBR Coastal Marine Park ZoningConservation ParkGeneral UseHabitat ProtectionMarine National ParkPort of GladstoneWestern Basin Supplementary EISLocation of East Banks Sea Disposal SiteJob NumberRevisionDate42-15386A14 April 2010Figure 18-1Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.com

Table 18-1 Number of sources and total mass flux of TSS per scenario without rehandlingScenario# ofDecantCSDDredging# of TSHDPumpout# of CSDdredge# of CSDrehandle# ofTSHDOverflow# ofTSHDDumpingErosionof MudWaveMassFlux(ton/day)1A 2 1 2 0.67 1 24351B 2 1 2 0.67 1 24352 1 1 1 0.67 1 20683 2 2 1 984It should be noted that the factor of 0.67 applied to the TSHD accounts for the longer cycle time. Thisrepresents approximately 40-45% of the source flux rate of the scenarios with rehandling.The use of TSHD dredging for the Clinton Bypass, Targinie Channel and Fisherman’s Landing regions isprimarily to not disrupt shipping at the Fisherman’s Landing port. An overflow mode needs to be adoptedotherwise insufficient dredge spoil material is filled in the hopper after 10 minutes (time to fill), which willconsist primarily of water, hence resulting in a large inefficiency.Though the previous table show that there is a large reduction in the total source flux of TSS withoutrehandling, there is an increase in the duration of dredging by 50%. Not only does this increase costssubstantially, but it also increases the duration of overflow dredging activities. Hence, rehandling benefitsare decreased costs and overall a shorter duration in the TSHD portion of the dredging program.However the cost is increased plume concentrations and their extent that can impact the Western Basinseagrass beds particularly during flood tides.The simulations clearly show that bottom dumping has a much larger impact on the Western Basinseagrass beds during flood tides. Hence, one hybrid option is to allow for only bottom dumping duringebb tides and TSHD pump out directly into the Reclamation Area during flood tides.18.2.1 Impact on Reef Water QualitySubmission #11 Provide detailed information about how this project contributes to the goals of the Reef Water QualityProtection Plan (2009) for the Great Barrier Reef World Heritage Area and adjacent catchments.In its currently proposed form (i.e. with rehandling in place), the Project will not have a measurableimpact on the reef, but rather be limited to the enclosed waters of Port Curtis. If variousrecommendations are made, several of the Project’s elements will reduce the potential impact to waterquality in the estuary and limit impacts throughout the study area, as discussed in subsequent sections inthis response (e.g. no dumping and rehandling of material by dredgers adjacent to the ReclamationArea).Numerical simulations indicate that TSS will not increase outside of the estuary. Hence, the first objectiveof the Reef Water Quality Protection Plan (2009), namely to ‘reduce the pollutant load from non-point42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document18-161

sources entering the reef’ will not likely to have a measurable impact on the offshore reefs outside of theestuary. As such, the Project is compliant with the Reef Plan (2009), as impacts to the water quality ofthe reef are not expected to be measurable.Should offshore disposal at the existing ground be considered beneficial, there will be some plumeactivity at the spoil ground, and this will be closer to areas of reef. Plume modelling work would beneeded to confirm that impacts were either low or manageable.Reductions in Turbidity associated with No Rehandling CaseChapter 10 of this document references some additional modelling results, and mapping plots.Reference can be made to these plots, which are included in both Chapter 10, and in Appendix C. Plotsare presented in Table 18-2.Table 18-2 Overview of dredge scenariosFigureReferenceDredgeScenarioRehandlingincluded?Description / Comment1 1a Yes Large plume (4 dredges)2 1b Yes Large plume (4)3 2 Yes Large plume (4)4 3 No Small plume – 2 CSDs only5 1a Yes As for 1a, only showing plume if over seagrass6 1b Yes 1b – plume over seagrass7 2 Yes As above8 3 No As above9 9 No Significant reduction in TSS. Most of area is now green (10to 30 mg/L)10 10 No Almost identical to Scenario 9. Relocation of decant fromNW to NE corner shows negligible benefit.11 9 No Scenario 9 over seagrass areas only12 10 No Scenario 10 over seagrass areas onlyReference to the full set of 10 spatial maps (Appendix C) provides several key highlights:The maps are presented for two cases: 10% exceedance (i.e. close to maximum, being exceededonly 10% of the time) and 50% (i.e. median).With rehandling included, the plumes are generally large in extent, affecting the northern part of theWestern Basin and the Passage Islands.The highest plume concentrations occur adjacent to the Reclamation Area (east and south).42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document18-162

Whilst significant plume concentrations can occur (refer left panel) with up to 100 mg/L close to thedredge for the 10% exceedance case, the majority of the area.Although the plumes extend into The Narrows and south towards Wiggins Island, the plume colour inthese areas is green, denoting an additional TSS of 10 to 30 mg/L.There is significant reduction in turbidity if rehandling is removed (dredge Scenario 9), with much ofthe remaining plume being relatively weak.Scenario 10 indicates that only a small incremental benefit accrues if the decant is moved, with theplots for Scenario 9 and 10 almost indistinguishable.Results are now discussed in more detail below in Section 18.3, with emphasis on the implications forseagrass areas.18.3 Ecological ImplicationsCurrently, there is a paucity of information regarding the tolerance limits of seagrasses in Port Curtis toincreases in turbidity from either natural or anthropogenic influences. Accordingly, a precautionaryapproach is required for management and implementation of any anthropogenic activity that mayincrease turbidity influences upon these sensitive ecosystems. Dredging activities, and the ways thedredged material are handled, are known to increase turbidity in the immediate vicinity of the dredger orrehandling activity and, depending on the characteristics of the dredged material, dredger and rehandlingactivities, may also create a plume over adjacent areas. With regard to the Project, dredgedmaterial rehandling has been predicted to generate a significant turbid plume through the dumpingprocess and the subsequent re-handling of this material using a CSD. In response to concerns about thepotential impacts of this and the ability to consider offshore disposal, a comparison of ecological impactsto Western Basin under scenarios including re-handling and no re-handling is provided here.The relative impact of different numbers of dredgers operating simultaneously for the Project has beendemonstrated through the modelling of different dredging scenarios. The scenario predicted to have thelargest impact on water quality in the region is that which has both cutter suction and trailer suctiondredgers operating simultaneously under a scenario of Stages 1A and 1B dredging activities occurringsimultaneously. This includes rehandling of materials from trailer suction dredger bottom dumpingadjacent to the Reclamation Area, into the reclamation ponds and decant from the reclamation ponds.The area the plume generates from this scenario has been modelled to impact includes potentially 1,406ha of seagrass meadows (Table 10-1). This estimated area was based on data assimilated from GHDstudies with the long term monitoring of seagrass meadows in Port Curtis and Rodds Bay that has beenconducted by the DEEDI since 2002.To estimate the area of seagrass that could be impacted by the Project dredge plume, the entirepotential area of seagrass habitat as mapped between all surveys conducted by DEEDI was calculatedby assimilating across all areas where seagrasses have occurred across all surveys. This gave apotential seagrass area (meadow + seed bank) within the Project footprint against which an assessmentof indirect impacts was made. This totals approximately 6,318 ha of benthic habitat, including 1,417.8 haof known seagrass habitat, which could be directly or indirectly impacted under the worst case scenarioof development and dredging works. The modelled rehandling scenarios (Figure 10-2 - Figure 10-5)42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document18-163

assume 24/7 dredging and rehandling activities and do not include any resting of sensitive habitats fromimpactive dredging and rehandling activities. These scenarios, therefore, assume the greatest level ofcumulative impact.As noted above, an option to utilise an offshore sea disposal site is being explored to reduce potentialturbidity loading impacts from dredging works. This option would remove the need for rehandling ofdredged materials and could, therefore, greatly reduce the associated impacts from re-handling onsurrounding sensitive habitats. No re-handling with offshore disposal, therefore, will provide a substantialenvironmental incentive. Hydrological modelling has been applied to investigate two alternative dredgingscenarios which do not include rehandling (Scenarios 9 and 10), to understand the comparativedifference of impacts from these options on surrounding benthic habitats in Port Curtis, including acomparison to Scenarios 1- 3 (Table 18-3).Table 18-3 Areas of seagrass (ha) under each plume contour predicted to be affected bydiffering plume concentrations for dredge Scenarios 9 and 10TSS PlumeConcentration10 th Percentile Exceedence 50 th Percentile ExceedenceDredge Scenario 9Dredge Scenario10DredgeScenario 9Dredge Scenario10>50 mg/L 1.08 0.00 0.00 0.00>40 mg/L 3.08 0.00 0.00 0.00>30 mg/L 6.61 0.00 1.27 0.00>20 mg/L 69.77 57.23 5.55 0.00>10 mg/L 896.89 927.21 188.86 190.65TOTALS 977.44 984.44 195.68 190.65Scenarios 9 and 10 provide a reduction in affected seagrass habitat when compared with Scenarios 1 -2(Table 18-4). Baseline monitoring for this region established a mean Total Suspended Solid (TSS) valueof 29 mg/L. The >30 mg/L TSS value was used for comparison across scenarios as for previousscenarios (1-3) and for Scenarios 9 and 10. This mean value obtained from baseline monitoring likelyrepresents a threshold of resilience to the current marine environment for seagrass persistence andresilience to impact and is, therefore, a potential trigger value for impacts.When comparing areas likely to be impacted by dredge plume concentrations greater than 30 mg/Lacross all dredge scenarios Scenario 10 shows the least level of impact with plumes being measured atless than 30 mg/L across the footprint of the Project Area. Figure 18-2 and Figure 18-3 show the areaspotentially affected in the Western Basin Project Area under Scenarios 9 and 10. The impacts toseagrass in Scenario 10 can only be observed up to 30 mg/L as turbidity was not modelled at valuesgreater than this. Scenario 9 is a less impactive option than Scenarios 1 and 2, however, rehandlingdredge Scenario 3 is marginally less impactive than this option (Table 18-4). Accordingly, the modelledturbidity values suggest the optimal environmental outcome would result from undertaking Scenario 1042/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document18-164

where no measurable areas of seagrass are expected to be impacted at the 10 th and 50 th percentiles for>30 mg/L turbidity level concentrations. Incorporating the offshore disposal of dredged material andrelocating the decant to the north-east corner of the Reclamation Area demonstrates a reduction inaffected habitat. By undertaking offshore disposal, a rest period between dredging cycles is alsopermitted allowing for periods of increased light availability to benthic habitats.Table 18-4 Comparison of dredge scenarios and predicted cumulative area of seagrass (ha)impactScenario TSS Contour (mg/L) Area of affected seagrass (ha)10 th Percentile 50 th Percentile1A >30 mg/L 245 511B >30 mg/L 311 1162 >30 mg/L 264 673 >30 mg/L 9 09 >30 mg/L 10 110 >30 mg/L 0 042/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document18-165

310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0007,380,000Scenario 9 at 10% Scenario 9 at 50%7,356,0007,356,0007,356,0007,356,0007,358,0007,358,0007,358,0007,358,0007,360,0007,380,0007,360,0007,380,0007,360,0007,360,0007,362,0007,362,0007,362,0007,362,0007,364,0007,364,0007,364,0007,364,0007,366,0007,366,0007,366,0007,366,0007,368,0007,368,0007,368,0007,368,0007,370,0007,370,0007,370,0007,370,0007,380,0007,372,0007,372,0007,372,0007,372,0007,374,0007,374,0007,374,0007,374,0007,354,0007,376,0007,376,0007,376,0007,376,0007,378,0007,378,0007,378,0007,378,000Based on or contains data provided by the State of Queensland . In consideration ofthe State permitting use of this data you acknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness, currency or suitability) andaccepts no liability (including without limitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data. Data must not be used for directmarketing or be used in breach of the privacy laws.7,354,0007,354,0007,354,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0001:120,000 (at A3) LEGENDo0 1 2 3 4 5KilometresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of AustraliaGrid: Map Grid of Australia 1994, Zone 56Data source: Aerial Photo (flown 2007) - DERM; Seagrass Data - DEEDI; Plume Data - WBM; Dredge Channels - GPC.Seagrass Areas MergedProposed Dredge AreasFisherman's Landing Northern ExpansionTSS (mg/L)10-3030-50Port of GladstoneWestern Basin Supplementary EISJob NumberRevisionDate42-15386A14 April 2010Western Basin Reclamation Area 50-100Seagrass Areas Affected byFigure 18-02Scenario 9 Dredge PlumeG:\42\15386\GIS\WesternBasinAdditionalInfo\Mxd\4215386_015.mxd© 2010. While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd, DERM, DEEDI, WBM and GPC make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.comGGHD Pty Ltd, DERM, DEEDI, WBM and GPC cannot accept liability of anykind (whether in contract, tort or otherwise) for anyexpenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.

310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0007,380,000Scenario 10 at 10% Scenario 10 at 50%7,356,0007,356,0007,356,0007,356,0007,358,0007,358,0007,358,0007,358,0007,360,0007,360,0007,360,0007,360,0007,380,0007,362,0007,380,0007,362,0007,362,0007,362,0007,364,0007,364,0007,380,0007,364,0007,364,0007,366,0007,366,0007,366,0007,366,0007,368,0007,368,0007,368,0007,368,0007,370,0007,370,0007,370,0007,370,0007,372,0007,372,0007,372,0007,372,0007,374,0007,374,0007,374,0007,374,0007,376,0007,376,0007,354,0007,376,0007,376,0007,378,0007,378,0007,378,0007,378,000Based on or contains data provided by the State of Queensland . In consideration ofthe State permitting use of this data you acknowledge and agree that the State gives no warranty inrelation to the data (including accuracy, reliability, completeness, currency or suitability) andaccepts no liability (including without limitation, liability in negligence) for any loss, damage or costs(including consequential damage) relating to any use of the data. Data must not be used for directmarketing or be used in breach of the privacy laws.7,354,0007,354,0007,354,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,000310,000312,000314,000316,000318,000320,000322,000324,000326,000328,000330,000332,0001:120,000 (at A3) LEGENDo0 1 2 3 4 5KilometresMap Projection: Universal Transverse MercatorHorizontal Datum: Geocentric Datum of AustraliaGrid: Map Grid of Australia 1994, Zone 56Seagrass Areas MergedProposed Dredge AreasFisherman's Landing Northern ExpansionWestern Basin Reclamation AreaTSS (mg/L)10-3030-5050-100Port of GladstoneWestern Basin Supplementary EISSeagrass Areas Affected byScenario 10 Dredge PlumeJob NumberRevisionDate42-15386A14 April 2010Figure 18-03G:\42\15386\GIS\WesternBasinAdditionalInfo\Mxd\4215386_016.mxd© 2010. While GHD has taken care to ensure the accuracy of this product, GHD Pty Ltd, DERM, DEEDI, WBM and GPC make no representations or warranties about its accuracy, completeness or suitability for any particular purpose.Level 4 201 Charlotte Street Brisbane QLD 4000 Australia T +61 7 3316 3000 F +61 7 3316 3333 E bnemail@ghd.com W www.ghd.comGGHD Pty Ltd, DERM, DEEDI, WBM and GPC cannot accept liability of anykind (whether in contract, tort or otherwise) for anyexpenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred as a result of the product being inaccurate, incomplete or unsuitable in any way and for any reason.Data source: Aerial Photo (flown 2007) - DERM; Seagrass Data - DEEDI; Plume Data - WBM; Dredge Channels - GPC.

19. Other19.1 Landscape and Visual Assessment19.1.1 Submission #11The EIS states that there is no current established methodology for landscape and visual impact. TheQueensland draft coastal protection plan 1009 released prior to this EIS contains a section includingdetailed methodology for determining visual and landscape impacts as a result of development.This comment in the WB EIS referred to the lack of an accepted methodology to cover the assessment oflandscape and visual impacts for specific projects in Queensland. This lack of an overall acceptedmethodology is reflected in the terms of reference for the Project, which does not include any referenceto assessment methodology on which the assessment was required to be based.The Draft State Planning Policy - Coastal Protection, contained within the Draft Queensland CoastalPlan, includes specific outcomes relating to Scenic Preference Values but not specific methodology forthis to be undertaken. This document makes reference to the 2001 study prepared by the Department ofNatural Resources, relating to the measurement of community appreciation of landscape aesthetics. Inaddition, Implementation Guideline No. 8 - Identifying and Protecting Scenic Amenity Values associatedwith the SEQ Regional Plan (prepared by the Office of Urban Management) also provides guidance tothe assessment of scenic amenity.The methodology used in the landscape and visual impact assessment section of the WB EIS does notconflict with these methodologies and meets the requirements of the terms of reference.19.2 Climate Change19.2.1 Submission #12 Modelling should only use the A1F1 scenario until the release of updated climate data.The climate change technical report for the WB EIS used the climate model data from the IPCC 2007report that uses the 2001 SRES scenarios. This report notes that based on studies published after theIPCC 2007 report, the higher range of these projections may be more likely than the lower range.Because of the IPCC’s AR5 is not due until 2014 with updated climate data, does the GPC’s riskmatrix and interpretational methodology similarly acknowledge the tracking of key climate indicatorsin the upper extremes?The climate change technical report for the WB EIS states that the rock armour protection that is likely tobe adopted at the Reclamation Area is based on a dynamic design. The rock armour, therefore, willmove to create a stable profile over its lifetime. It is recognised that maintenance may be required overthe design life of the reclamation. Therefore, risk assessments would need to be carried out cyclicallyover the life of the reclamation, incorporating any new information (including updated climate changescenarios) as they become available.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document19-168

19.3 Temperature Inversions19.3.1 Submission #12The EIS states that no data is available for temperature inversions in the Gladstone area. This is aconcern because inversions from cooler onshore flows (and highs) can lead to industrial pollutantsbecoming trapped close to the earth's surface. Further analysis is needed, and while the project isunlikely to contribute to the Gladstone ‘airshed’, it supports the development of industry that will.Submission suggests that the collection of localised temperature inversion data should beundertaken to ascertain frequency and severity (as part of the project’s Cumulative ImpactAssessment).Temperature inversions are primarily of relevance to the proposed LNG plants on Curtis Island.However, an excerpt from the GLNG EIS (Section 8.2.2.7) is reproduced below and provides informationon temperature inversions that is relevant to the Gladstone environs:“Air temperature generally decreases with altitude, with buoyancy causing the air to mix vertically. This istypical of sunny daytime conditions which are described as unstable. Temperature inversions occur whenthe temperature increases with height, which may only occur in a shallow band of air. This has the effectof trapping colder parcels of air below the warmer air above. Any pollution source that is emitted belowthis will have limited opportunity for dilution with fresh air. This effect also applies to ground-level noisesources. Inversions commonly develop at night, when the surface cools due to radiation heat loss to theatmosphere.Temperature inversions often create the worst-case meteorological conditions for air dispersion andnoise transmission, and thus are critical conditions for adverse impacts at nearby locations. The EPA’sPlanning for Noise Control guideline notes that temperature inversions can create significant noiseimpacts that warrant further assessment if they occur more than 30% of the time under the followingconditions:Winter (June, July and August);Night-time period (between 1800 to 0700 hours);Temperature inversion strength of at least 3 C per 100 m plus a source-to-receiver drainage flowwind speed of 2 m/s; andModerate (F-class stability) inversions.The frequency of temperature inversions at Curtis Island has been determined from the Calmet modelledmetrological data for 2001 (Appendix S). These data were extracted from all the vertical levels in themodel (between 10 m and 2,750 m elevation above ground level) for June, July and August. An inversionlasting at least one hour (the time-step that is used in Calmet) was found to occur for approximately 2%of hours in the year, or 141 separate inversion events over 30 days in winter. This equates to 18% of thehours in June, July and August, representing the conditions under which adverse air quality and noiseimpacts are most likely to cause nuisance.”42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document19-169

While this information focuses on noise impacts rather than air quality, it demonstrates that inversionslasting at least one hour only occurred 2% of the hours in the year from the data used. Furthermore, theWestern Basin Dredging and Disposal Project is not expected to contribute to any increase in pollutantsthat may be trapped beneath temperature inversion events.19.4 Groundwater19.4.1 Submission #12Consider all four proposed LNG pipelines in the potential cumulative impacts on groundwater.The WB EIS addresses the construction of the outer bund wall of the proposed reclamation, capital andmaintenance dredging, dredge placement within the Reclamation Area and capping, surface stabilisationand stormwater management. It does not address pipeline construction for the LNG projects.It is recognised that there are a number of pipelines associated with the LNG industry with the potentialto cumulatively impact on groundwater resources, and it is a requirement that impacts associated withthese pipelines will be addressed by each of the proponents.19.4.2 . Submission #12State the post construction timeframe for groundwater monitoring in the EIS.A post construction timeframe for groundwater monitoring will take into consideration the groundwatermonitoring results collected during construction and therefore cannot be confirmed prior to construction.This will be incorporated into the groundwater monitoring plan as part of the EMP for the Project.19.5 Cost/Benefit Analysis19.5.1 Submission #17The submission states that the cost-benefit analysis is not correct. The 1,000 acres has been valuedat between $1.4 and $2.4 million per acre (i.e. the environmental dis-benefits). This figure is notcorrect as it is the value that is attributed to this environment for a life of 20 years only.The economic value of the directly impacted habitat (or habitat lost) as a result of the Project is based onparameter values used by the Queensland Government’s Department of Environment and ResourceManagement. These parameter values are based on a meta-analysis of environmental valuation studies(i.e. Costanza, R., d’Arge, R., de Groot, R., Faber, S., Grasso, M., Limburg, K., Naeem, S., O’Neil, R.,Paruelo, J., Raskin, R., Sutton, P. & van den Belt, M. (1997) “ The value of the world’s ecosystemservices and natural capital”, Nature, Vol. 387, May 1997, pp. 253-260). These parameter values tend tobe at the upper end of the range for economic values of marine habitat, particularly when compared withAustralian studies.The submission incorrectly asserts that the dis-benefits are calculated for a Project life of 20 years. TheProject life assessed is 40 years plus a three year construction period.The values reported in the submissions do not reflect values within the literature, nor are theyreferenced.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document19-170

The issue of discounting within environmental assessments can be difficult to address. An alternative todiscounting is capitalizing the dis-benefit. However, the discounted value of the direct environmental disbenefitsis estimated at approximately $249 million. Capitalising the direct environmental dis-benefitwould result in an estimate of $273 million, increasing dis-benefits attributable to the loss of habitat byapproximately $24 million. The Project has an estimated net present value of approximately $1.21 billion,hence the alternative approach would not result in the Project being economically negative.Were the higher and unsubstantiated values adopted, the Project would remain economically positive.19.6 Fossil Fuels19.6.1 Submission #11EIS states that development of LNG industry will "reduce reliance on fossil fuels such as coal". LNGis a fossil fuel. Also, provide information on coal exports from the new facility.It is acknowledged that LNG is a fossil fuel, however the statement above was made in relation to thefact that natural gas is widely seen as the cleanest of all the fossil fuels. Natural gas burns more cleanlythan other fossil fuels, and when combusted, has fewer emissions of sulfur, carbon dioxide, carbonmonoxide, and nitrogen than coal or oil. It also leaves almost no ash or particulate matter.As the cleanest of the fossil fuels, natural gas can be used in many ways to help reduce the emissions ofpollutants into the atmosphere. Burning natural gas in the place of other fossil fuels emits fewer harmfulpollutants into the atmosphere, and an increased reliance on natural gas can potentially reduce theemission of many of these most harmful pollutants.The WB EIS does not include a coal export terminal. The Wiggins Island project, which was subject to aseparate EIS process, involved a coal export facility.19.7 Maritime Heritage19.7.1 Submission #2The EMP must include appropriate mitigation measures for any cultural heritage artefacts orshipwrecks that may be discovered during dredging and reclamation operations.Amend the EMP to accord with requirements of Federal and State legislation relating toarchaeological artefacts and shipwrecks (Queensland Heritage Act 1992 and Historic Shipwrecks Act1976).Management MeasuresIf any archaeological artefacts (including shipwrecks) are discovered during the course of construction,steps in accordance with Sections 89 and 90 of the Queensland Heritage Act 1992 and the HistoricShipwrecks Act 1976 will be carried out. These may include:Stopping work in the vicinity of the discoveries of archaeological artefacts of shipwrecks;A process of assessment of significance (i.e. by a suitably qualified archaeologist);Temporary conservation and storage of any artefacts; and42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document19-171

Reporting to the appropriate authority (DERM or the Queensland Museum).The EMP will be updated to reflect these management measures.19.8 Cumulative and Consequential Impacts19.8.1 Submission #4EIS should address cumulative and consequential impacts of potential developments related to theWestern Basin Strategic Dredging and Disposal Project e.g. increased shipping activity and thevarious proposals relating to linear infrastructure across ‘The Narrows’ to Curtis Island.An assessment of cumulative impacts was completed for the WB EIS. Figure 6-1 of Appendix Q of theWB EIS shows the existing and proposed industries for the coastal developments in the Gladstone area.In regards to linear infrastructure it should be noted that the WB EIS does not include any dredgingrelating to the pipelines crossing. It should also be noted that at the time of writing (late March 2010) nofirm details are available on the pipelines or the method of installation. Therefore, it is not possible toinclude any meaningful comment on the impacts of the pipelines at this stage. The pipelines will besubject to a separate approvals process involving the LNG proponents (either separately orcumulatively).The other piece of linear infrastructure is the potential bridge. Currently GPC have no firm advice on thebridge location, type or potential construction commencement date. It is therefore not possible tocomment on the impacts of this structure, other than to add that the bridge will also be subject to aseparate approval process.19.9 Marine Incidents19.9.1 Submission #1 The Oil Spill Response Plan appears to be based on incidents in the port during the period 1985-1998. There have been several further incidents since that time (e.g. Global Peace). The proponentshould liaise with the Regional Harbour Master (Gladstone) to obtain the latest data on marineincidents in the Port of Gladstone, to determine if the risk assessment and mitigation measuresdetailed in the EIS are still valid.GPC undertakes to consult the RHM in the process of updating GPC's Oil Response Plan. Further, GPCwill liaise with the RHM in the formulation of the relevant areas of the DMP.42/15386/400126 Western Basin Dredging and Disposal ProjectEIS Supplementary Information Document19-172

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