Dunlin Alpha Environmental Appraisal Report
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Dunlin Alpha Decommissioning Environmental Appraisal Report This Dunlin Alpha Decommissioning Environmental Appraisal Report is a supporting document to the Draft Decommissioning Programme alongside the Comparative Assessment Report and other documentation, available on FEL website (http://www.fairfield-energy.com). Page 2 of 155 Dunlin Alpha Decommissioning Environmental Appraisal Report Contents Acronyms ........................................................................................................................................................... 5 Non-Technical Summary ................................................................................................................................... 8 1. Introduction ............................................................................................................................................... 18 1.1. The Greater Dunlin Area .................................................................................................................... 18 1.2. The Dunlin Alpha Decommissioning Project ...................................................................................... 20 1.3. Regulatory Context ............................................................................................................................ 22 1.4. Environmental Management .............................................................................................................. 25 1.5. Scope and Structure of this Environmental Appraisal Report ........................................................... 25 2. Project Description ................................................................................................................................... 27 2.1. Description of Facilities to be Decommissioned ................................................................................ 27 2.2. Consideration of Alternatives and Selected Approach ...................................................................... 42 2.3. Decommissioning Activities ............................................................................................................... 48 3. Environmental Appraisal Methodology ..................................................................................................... 55 3.1. Identification of Environmental Issues ............................................................................................... 55 3.2. Stakeholder Engagement .................................................................................................................. 57 3.3. Environmental Significance ................................................................................................................ 58 3.4. Cumulative Impact Assessment ......................................................................................................... 66 3.5. Transboundary Impact Assessment .................................................................................................. 66 3.6. Habitats Regulations Assessment (HRA) and Nature Conservation Marine Protected Area Assessment .................................................................................................................................................. 66 4. Environment Baseline .............................................................................................................................. 68 4.1. Weather and Sea Conditions ............................................................................................................. 68 4.2. Bathymetry and Seabed Conditions .................................................................................................. 69 4.3. Biological Environment ...................................................................................................................... 76 4.4. Conservation ...................................................................................................................................... 89 4.5. Socio-Economic Environment ............................................................................................................ 93 5. Impact Assessment ................................................................................................................................ 100 5.1. Cell Contents – Gradual Release Over Time .................................................................................. 100 5.2. Cell Contents – Instantaneous Release........................................................................................... 107 5.3. Drill Cuttings Disturbance ................................................................................................................ 117 5.4. Physical Presence............................................................................................................................ 130 5.5. Waste ............................................................................................................................................... 132 Page 3 of 155 Dunlin Alpha Decommissioning Environmental Appraisal Report 6. Conclusions ............................................................................................................................................ 138 7. References ............................................................................................................................................. 139 Appendix A – ENVID Matrix .......................................................................................................................... 145 Appendix B – Modelling Details ..................................................................................................................... 152 B.1 Overview ........................................................................................................................................... 152 B.2 Modelling Software ........................................................................................................................... 152 B.3 Modelling Limitations ........................................................................................................................ 153 B.4 Modelling Inputs ................................................................................................................................ 153 Page 4 of 155 Dunlin Alpha Decommissioning Environmental Appraisal Report Acronyms % Percent £ Pound sterling ° Degrees °C Degrees Celsius µm Micrometre μgg-1 Microgram per gram AIS Automatic Identification System ALARP As Low as Reasonably Practicable ANDOC Anglo Dutch Offshore Concrete AORP Attic Oil Recovery Project BAOAC Bonn Agreement Oil Appearance Code BEIS Department for Business, Energy and Industrial Strategy BODC British Oceanographic Data Centre BTEX Benzene, Toluene, Ethylbenzene and Xylene CCTR Cell Contents Technical Report CGBS Concrete Gravity Base Substructure Cm Centimetre CO2 Carbon Dioxide DECC Department of Energy and Climate Change (now BEIS) DFGI Dunlin Fuel Gas Import DP Decommissioning Programme DPI Dunlin Power Import DSV Dive Support Vessel EA Environmental Appraisal EBS Environmental Baseline Survey EIA Environmental Impact Assessment EIF Environmental Impact Factor EMS Environmental Management System EPS European Protected Species EU European Union EUNIS European Nature Information System FEL Fairfield Energy Limited Ft Feet ft3 Cubic feet g/m2 Grams per metre squared g/m3 Grams per metres cubed Helideck Helicopter deck HLV Heavy Lift Vessel Page 5 of 155 Dunlin Alpha Decommissioning Environmental Appraisal Report HRA Habitats Regulations Assessment HSE Health and Safety Executive ICES International Council for the Exploration of the Sea IMO International Maritime Organisation IPCC Intergovernmental Panel on Climate Change ISO International Organisation for Standardisation ITOPF International Tanker Owners Pollution Federation IUCN International Union for Conservation of Nature JNCC Joint Nature Conservation Committee kg Kilogram km Kilometre km2 Square kilometre km3 Cubic kilometre LAT Lowest astronomical tide LoD Limit of Detection LSA Low specific activity m Metre m/s Metres per second m2 Square metre m3 Cubic metre MCDA Multi Criteria Decision Analysis MCZ Marine Conservation Zone MEMW Marine Environmental Modelling Workbench MMO The Marine Management Organisation MPA Marine Protected Area MSF Modular Support Frame MSH Make Safe and Handover Navaid Navigation Aid NCMPA Nature Conservation Marine Protected Area Nm Nautical Miles NORM Naturally Occurring Radioactive Material OGA UK Oil and Gas Authority OGUK Oil and Gas UK OPEP Oil Pollution and Emergency Plan OPF Organic Phase Fluids OPRED Offshore Petroleum Regulator for Environment and Decommissioning OSPAR Oslo Paris Convention P&A Plug and Abandonment PEC Predicted effect concentration pH Potential hydrogen Page 6 of 155 Dunlin Alpha Decommissioning Environmental Appraisal Report PMF Priority Marine Feature PNEC Predicted no-effect concentration SAC Special Area of Conservation SAHFOS Sir Alister Hardy Foundation for Ocean Science SCI Site of Community Importance SCOS Special Committee on Seals SEA Strategic Environmental Assessment SIMOPs Simultaneous operations SMRU Sea Mammal Research Unit SNH Scottish Natural Heritage SOSI Seabird Oil Sensitivity Index SPA Special Protection Area THC Total Hydrocarbon Content TOC Total Organic Carbon TOM Total Organic Matter UK United Kingdom UKBAP United Kingdom Biodiversity Action Plan UKCS United Kingdom Continental Shelf UKOOA United Kingdom Offshore