Dublin Array Offshore Wind Farm Environmental Impact Assessment Scoping Report Date: September 2020 Revision: 1 Revision Prepared Checked Approved 0.1 (Internal) SLR/GoBe/RWE AJM/MB (SLR) PK (RWE) GM/HM (RWE) 0.2 (Internal) SLR/GoBe/RWE AJM/MB (SLR) PK (RWE) GM/HM (RWE) 0.3 (Internal) SLR/GoBe/RWE AJM/MB (SLR) PK (RWE) GM/HM (RWE) 1 (External) SLR/GoBe/RWE AJM/MB (SLR) PK (RWE) GM/HM (RWE) Contents 1 Introduction....................................................................................................................................1 1.2 Document Structure ...............................................................................................................1 1.3 Project Background.................................................................................................................2 1.4 Current Project Status ............................................................................................................4 2 Project Description .........................................................................................................................5 2.1 Introduction............................................................................................................................5 2.2 Design Envelope .....................................................................................................................5 2.3 Offshore Infrastructure...........................................................................................................6 2.4 Onshore Infrastructure.........................................................................................................21 3 Environmental Impact Assessment Methodology........................................................................32 3.1 Overview...............................................................................................................................32 3.2 Guidance...............................................................................................................................34 3.3 EIA Screening ........................................................................................................................35 3.4 EIA Scoping ...........................................................................................................................35 3.5 Consideration of Alternatives...............................................................................................35 3.6 Receiving Environment.........................................................................................................36 3.7 Impact Assessment Process..................................................................................................36 3.8 Approach to Assessment of Project Design..........................................................................41 3.9 Approach to Interactions of Environmental Factors.............................................................41 3.10 Approach to Cumulative Assessment ...................................................................................42 3.11 Approach to Transboundary Assessment.............................................................................43 3.12 Mitigation Measures and Monitoring...................................................................................43 3.13 Residual effects.....................................................................................................................44 3.14 Appropriate Assessment.......................................................................................................45 4 EIAR Structure...............................................................................................................................48 4.1 Introduction..........................................................................................................................48 5 Specialist Topics Offshore.............................................................................................................54 5.1 Introduction..........................................................................................................................54 5.2 Physical Processes and Marine Water and Sediment Quality ..............................................54 5.3 Underwater Noise.................................................................................................................64 5.4 Benthic and Intertidal Ecology..............................................................................................65 5.5 Fish and Shellfish Ecology .....................................................................................................73 5.6 Offshore Ornithology............................................................................................................81 5.7 Marine Mammals .................................................................................................................89 5.8 Seascape, Landscape and Visual Amenity ............................................................................96 5.9 Shipping and Navigation.....................................................................................................104 5.10 Aviation...............................................................................................................................113 5.11 Commercial Fisheries..........................................................................................................118 5.12 Infrastructure and Other Uses............................................................................................127 5.13 Marine Archaeology ...........................................................................................................137 6 Onshore Specialist Topics ...........................................................................................................144 6.1 Introduction........................................................................................................................144 6.2 Biodiversity .........................................................................................................................144 6.3 Land, Soils and Geology ......................................................................................................152 6.4 Water (Hydrology, Hydrogeology and Flood Risk)..............................................................159 6.5 Air Quality and Climate Change..........................................................................................164 6.6 Noise and Vibration ............................................................................................................168 6.7 Traffic and Transport ..........................................................................................................172 6.8 Cultural Heritage (Archaeology and Monuments)..............................................................177 6.9 Landscape and Visual..........................................................................................................184 6.10 Socio-economic, tourism, recreation and land use ............................................................189 6.11 Other Issues........................................................................................................................196 References Appendices Appendix 1..........................................................................................................................................199 Figures Figure 1 - Proposed Dublin Array Site Boundary and Export Cable Search Area....................................3 Figure 2 - A typical wind turbine generator...........................................................................................7 Figure 3 - Sequential photographs of installation of turbine tower, nacelle and blades .......................8 Figure 4 - Foundation Options...............................................................................................................9 Figure 5 - Offshore substation at Gwynt y Mor Wind Farm in Wales...................................................13 Figure 6 - Typical single armoured submarine cable – Source GGOWL (2009) ....................................16 Figure 7 - Onshore Grid Connection Points and Indicative Landfall Locations.....................................22 Figure 8 - Overview of the onshore grid connection infrastructure.....................................................23 Figure 9 - TJB Construction...................................................................................................................24 Figure 10 - TJB contruction site – RWE Renewables Gwynt y Mor Offshore Wind Farm in Wales ......25 Figure 11 - Typical HV Trench Excavation (Ducts laid in trefoil formation) – ESBI HV Cables – General Construction Methodology 2012..........................................................................................................26 Figure 12 - Typical Joint bay under construction alongside a public road (HV Cables General Construction Methodology, ESBI 2012)................................................................................................27 Figure 13 - Typical Substation Layout (RWE Renewables Galloper Offshore Wind Farm in UK)..........30 Figure 14 The EIA Process and the position of the EIAR (EPA 2017) ....................................................33 Figure 15 - Geographical overview of the bathymetry.........................................................................58 Figure 16 - Geographical overview of the seabed