Issue number: BT-JAC-020631-550-0002-EIA Bramford to Twinstead Scoping Report May 2021 Page left intentionally blank National Grid | May 2021 | Bramford to Twinstead i Contents Contents ii 1. Introduction 1 1.1 Overview 1 1.2 Need for the Project 1 1.3 Geographical Context 3 1.4 Purpose of this Report 4 1.5 Transboundary Effects 6 2. Regulatory and Planning Policy Context 7 2.1 Introduction 7 2.2 The Infrastructure Planning (EIA) Regulations 2017 7 2.3 Electricity Act 1989 8 2.4 Countryside and Rights of Way Act 2000 8 2.5 National Planning and Energy Policy 8 2.6 Local Planning Policies 11 2.7 National Grid Policy and Guidance 11 3. Main Alternatives Considered 12 3.1 Introduction 12 3.2 National Grid Approach to Options Appraisal 13 3.3 Overview 14 3.4 Strategic Options 15 3.5 Route Corridor Options 16 3.6 Identification of the Preferred Corridor 18 3.7 Alignment Options 18 3.8 Further Work Undertaken After Identifying the Interim Alignment 20 3.9 Distribution Network Options 23 3.10 Current Indicative Alignment and Embedded Measures 24 4. Project Description 26 4.1 Overview of the Project 26 4.2 DCO Terminology and Assumptions 27 4.3 Description of Each Section of the Scoping Boundary 28 4.4 Good Design Principles 31 4.5 Description of Project Components and Construction Methods 33 4.6 Operation and Maintenance 38 4.7 Decommissioning 40 4.8 Embedded Measures 40 National Grid | May 2021 | Bramford to Twinstead ii 5. Environmental Impact Assessment Approach and Method 41 5.1 Introduction 41 5.2 General Approach 41 5.3 Geographical and Temporal Scope 41 5.4 Embedded and Good Practice Measures 43 5.5 Assessment of Effects and Determination of Significance 43 5.6 Mitigation 46 5.7 Residual Effects 46 5.8 Cumulative Effects 46 5.9 Monitoring 46 6. Landscape and Visual 47 6.1 Introduction 47 6.2 Regulatory and Planning Policy Context 47 6.3 Study Area 48 6.4 Existing Baseline 49 6.5 Embedded and Good Practice Measures 60 6.6 Likely Significant Effects 62 6.7 Proposed Assessment Methodology 65 6.8 Ascribing Value/Sensitivity 67 6.9 Conclusion 74 7. Biodiversity 76 7.1 Introduction 76 7.2 Regulatory and Planning Policy Context 76 7.3 Approach and Methods 77 7.4 Study Area 78 7.5 Existing Baseline 79 7.6 Embedded and Good Practice Measures 87 7.7 Likely Significant Effects 89 7.8 Proposed Assessment Methodology 97 7.9 Conclusion 99 8. Historic Environment 102 8.1 Introduction 102 8.2 Regulatory and Planning Policy Context 102 8.3 Study Area 103 8.4 Existing Baseline 103 8.5 Embedded and Good Practice Measures 107 8.6 Likely Significant Effects 107 8.7 Proposed Assessment Methodology 110 8.8 Conclusion 114 National Grid | May 2021 | Bramford to Twinstead iii 9. Water Environment 117 9.1 Introduction 117 9.2 Regulatory and Planning Policy Context 117 9.3 Study Area 118 9.4 Existing Baseline 118 9.5 Embedded and Good Practice Measures 121 9.6 Likely Significant Effects 122 9.7 Proposed Assessment Methodology 124 9.8 Conclusion 126 10. Geology and Hydrogeology 128 10.1 Introduction 128 10.2 Regulatory and Planning Policy Context 128 10.3 Study Area 129 10.4 Existing Baseline 129 10.5 Embedded and Good Practice Measures 131 10.6 Likely Significant Effects 132 10.7 Proposed Assessment Methodology 134 10.8 Conclusion 137 11. Agriculture and Soils 139 11.1 Introduction 139 11.2 Regulatory and Planning Policy Context 139 11.3 Study Area 140 11.4 Existing Baseline 140 11.5 Embedded and Good Practice Measures 142 11.6 Likely Significant Effects 143 11.7 Proposed Assessment Methodology 145 11.8 Conclusion 147 12. Traffic and Transport 148 12.1 Introduction 148 12.2 Regulatory and Planning Policy Context 148 12.3 Study Area 149 12.4 Existing Baseline 149 12.5 Embedded and Good Practice Measures 152 12.6 Likely Significant Effects 153 12.7 Proposed Assessment Methodology 155 12.8 Conclusion 161 13. Air Quality 163 13.1 Introduction 163 13.2 Regulatory and Planning Policy Context 163 National Grid | May 2021 | Bramford to Twinstead iv 13.3 Study Area 163 13.4 Existing Baseline 164 13.5 Embedded and Good Practice Measures 167 13.6 Likely Significant Effects 168 13.7 Proposed Assessment Methodology 169 13.8 Conclusion 172 14. Noise and Vibration 173 14.1 Introduction 173 14.2 Regulatory and Planning Policy Context 173 14.3 Study Area 173 14.4 Existing Baseline 174 14.5 Embedded and Good Practice Measures 175 14.6 Likely Significant Effects 177 14.7 Proposed Assessment Methodology 179 14.8 Conclusion 182 15. Socio-Economics, Recreation and Tourism 184 15.1 Introduction 184 15.2 Regulatory and Planning Policy Context 185 15.3 Study Area 186 15.4 Existing Baseline 186 15.5 Embedded and Good Practice Measures 195 15.6 Likely Significant Effects 195 15.7 Conclusion 201 16. Health and Wellbeing 203 16.1 Introduction 203 16.2 Regulatory and Planning Policy Context 204 16.3 Approach to Scoping 204 16.4 Study Area 205 16.5 Existing Baseline 205 16.6 Embedded and Good Practice Measures 206 16.7 Likely Significant Effects 207 16.8 Conclusion 207 17. Major Accidents and Disasters 209 17.1 Introduction 209 17.2 Regulatory and Planning Policy Context 209 17.3 Approach to Scoping 209 17.4 Study Area 210 17.5 Existing Baseline 211 17.6 Embedded and Good Practice Measures 214 National Grid | May 2021 | Bramford to Twinstead v 17.7 Likely Significant Effects 215 17.8 Conclusion 216 18. Cumulative Effects 218 18.1 Introduction 218 18.2 Regulatory and Planning Policy Context 218 18.3 Approach to Scoping 219 18.4 Existing Baseline 220 18.5 Embedded and Good Practice Measures 221 18.6 Proposed Assessment Methodology 221 18.7 Likely Significant Effects 225 18.8 Conclusion 226 19. Environmental Management and Mitigation 227 19.1 Introduction 227 19.2 Proposed Securing Mechanisms 227 19.3 Environmental Management Post Consent 227 20. Conclusion 228 20.1 Introduction 228 20.2 Topics Proposed to be Scoped In and Out 228 20.3 Proposed Contents of the ES 232 20.4 Next Steps 234 Acronyms 235 Glossary 239 References 248 Legislation 248 Other Documents 248 National Grid | May 2021 | Bramford to Twinstead vi 1. INTRODUCTION 1.1 Overview 1.1.1 National Grid Electricity Transmission plc (hereafter referred to as National Grid) owns builds and maintains the electricity transmission network in England and Wales. Under the Electricity Act 1989, National Grid holds a transmission licence, under which it is required to develop and maintain an efficient, coordinated and economical electricity transmission system. National Grid is also required to consider ways to preserve amenity under Schedule 9 of the Act. 1.1.2 National Grid intends to submit an application for an order granting development consent to reinforce the transmission network between Bramford Substation in Suffolk, and Twinstead Tee in Essex (Figure 1.1). This would be achieved by reinforcing the network with a new 400 kilovolt (kV) electricity transmission line over a distance of 27km (16.7 miles), the majority of which would follow the general alignment of the existing overhead line network. 1.1.3 The reinforcement would be a combination of overhead line (conductors) and underground cable, and it is proposed that approximately 26.5km of existing overhead line could then be removed (25km of existing 132kV overhead line between Burstall Bridge and Twinstead Tee, and 1.5km of the existing Bramford-Braintree-Rayleigh 400kV overhead line to the south of Twinstead). To facilitate the overhead line removal a new grid supply point (GSP) substation is proposed at Butler’s Wood, south of Sudbury, in Essex. 1.1.4 The Bramford to Twinstead project (‘the project’) is a Nationally Significant Infrastructure Project (NSIP), as defined under Part 3 of the Planning Act 2008 and some aspects constitute associated development. 1.1.5 The Scoping Report presents the ‘Indicative Alignment’, which is the current alignment identified to date in the options appraisal work. The Indicative Alignment has the potential to change as a result of ongoing technical and environmental assessments and also as a result of consultation feedback. The project will need to identify the proposed Order Limits as part of the application for development consent, which will comprise the land used during construction of the project. As the Order Limits are not yet defined and as the Indicative Alignment could be refined, a precautionary 250m buffer has been assumed around the Indicative Alignment in the Scoping Report in order to scope the potential significant effects of the project. This area has been called the ‘Scoping Boundary’ and is shown on Figure 1.1 and other associated figures in Volume 3. The proposed Order Limits will be defined at the next stage of the project and will replace the Scoping Boundary as the basis for the project assessment area within the future Environmental Statement (ES). 1.2 Need for the Project 1.2.1 The project initially commenced in 2009, when a need to reinforce the network between Bramford Substation and Twinstead Tee was originally identified. National Grid considered alternative strategic options to reinforce the network and alternative route corridors, as part of the options appraisal process (see Chapter 3: Main Alternatives Considered). The reinforcement was necessary to support the connection of new generation projects in East Anglia, primarily new nuclear and wind.