Offshore Energy SEA 2 5 ASSESSMENT 5.1 Assessment approach and methodology This SEA covers an enormous marine area comprising all UK waters with water depth from the intertidal to more than 2,400m. The draft plan/programme includes for the licensing of offshore oil and gas activities, the storage of gas and CO2, offshore wind farms and marine renewables. The assessment therefore has to address complex issues and multiple interrelationships, where a simplistic score based matrix assessment would be inadequate. Following discussion with the SEA Steering Group an evidence based consideration was agreed. In addition, significant use has been made of Geographical Information System (GIS) tools to collate, process, analyse and present spatial information. The assessment for this SEA is a staged process (Figure 5.1) incorporating inputs from a variety of sources: • Baseline understanding of the relevant receptors (including other users) grouped according to the SEA Directive (see Appendix 3 Environmental baseline and Section 4 Environmental information and the range of underpinning technical reports produced for the SEA process) together with existing environmental problems and the likely evolution of the baseline conditions. Given the comprehensive nature of the environmental baseline produced for OESEA, only updates to the baseline section since the publication of OESEA or baseline information relevant to the new aspects of the OESEA2 draft plan/programme are included in this report. • The likely activities, and potential sources of effect (see Box 5.1) and the existing mitigations, regulatory and other controls (see Appendix 5). • The evolving regulatory framework. • The evolution of technology. • The SEA objectives (see Section 3). • The evidence base regarding the relative risks and potential for significant effects from offshore wind farm, wave, tidal stream and tidal range developments, offshore oil and gas exploration and production, carbon dioxide storage and gas storage related activities. • Steering Group, statutory consultee and stakeholder perspectives on important issues, information sources and gaps, and potential areas to exclude from licensing derived from scoping, assessment workshop, regional stakeholder workshops, sector workshops, meetings and other communications – see Appendix 1 and 2. At a strategic level, a distinction has been drawn for various effect mechanisms between impacts which may be significant in terms of conservation status of a species or population (and hence are significant in strategic terms), and impacts which may be significant to individual animals, but which will not influence sufficient numbers to have a significant effect on population viability or conservation status (and hence strategically significant). February 2011 79 Environmental Report Offshore Energy SEA 2 Examples of this approach include the consideration of acoustic effects on marine mammals, collision risk for birds and oil spill effects. This approach does not imply that mortality or sub- lethal effects on individual animals are unimportant (clearly there are welfare considerations, particularly for avian and mammalian species); but it is appropriate that strategic considerations are made at a biogeographic population or species level – as is done for example, in the selection of qualifying features for Natura 2000 sites. Figure 5.1 – Assessment process Working list of SEA topics/issues Inputs to SEA Assessment Process: objectives & indicators (scoping) Inputs to SEA Assessment Process: - Issues of stakeholder & public concern - Draft plan/programme - Major reviews of effects - Oil & gas, carbon dioxide storage, gas - Scientific & "grey" literature storage, wave, tidal & offshore wind - The evolving Natura 2000 network Expert assessment workshop farm activities - Future MSP - MCZs/MPAs - Round 3 screening - Other marine industries and uses - Feedback from scoping - SEA studies & syntheses - Previous/other relevant SEAs & EIAs - Relevant guidelines & guidance - Hierarchy of environmental protection SEA topics/issues - Legislation objectives objectives & indicators - New information from surveys - Environmental baseline & likely evolution - Feedback from previous DECC SEA - Existing environmental problems consultations - Potential activity scenarios - Results from relevant monitoring Sector & regional stakeholder - Present & likely technologies workshops - Present & potential mitigation Potentially significant effects at a Possible minor effects at a No negative effects expected regional/transboundary level regional level Positive effects further assessed Evaluation to confirm Further assessment Inter-relationships spatial, synergistic, cumulative Conclusions & recommendations including monitoring Environmental Report 5.2 Potential sources of significant effects Potential sources of effects from the activities which could follow adoption of the draft plan/programme have been variously discussed with the SEA Steering Group and stakeholders (see Appendix 1 & 2) in terms of the likely significant effects on the environment, including on the SEA topics – these are listed in Box 5.1 below. A questionmark indicates uncertainty of potential for effect. The sources of potentially significant effect identified in Box 5.1 have been categorised by Assessment Topic (left hand column, see key at end of table) which forms the basis of the subsequent assessment sections. The potentially significant effects identified in Box 5.1 represent potential issues which merit further consideration (location of assessment signposted in right hand column, Assessment Section). Environmental Report 80 February 2011 Offshore Energy SEA 2 Box 5.1 Sources of potentially significant effect Storage Wave Wave Topic farms farms 2 Section Oil & Gas Tidal Range Tidal Range CO Gas Storage Gas Storage Assessment Assessment Assessment Tidal Stream Tidal Stream Offshore Wind Wind Offshore SEA Topic Biodiversity, habitats, flora and fauna 5.4.2.1 Physical damage to habitats from infrastructure construction, vessel/rig anchoring etc X X X X X X X 5.4.2.2 Potential behavioural and physiological effects on marine mammals, birds and fish from seismic 5.3.2.1 X X X surveys 5.3.2.2 Potential behavioural and physiological effects on marine mammals, birds and fish associated 5.3.2.1 X X X X X X X with piling and construction noise 5.3.2.2 Potential behavioural and physiological effects on marine mammals, birds and fish associated 5.3.2.1 X X X X X X X with operational noise 5.3.2.2 Potential behavioural and physiological effects on marine mammals, birds and fish associated 5.3.2.1 X X X X X X X with decommissioning noise 5.3.2.2 Potential for non-native species introductions in ballast water discharges or spread through 5.6.2.4 X X X X X X X “stepping stone” effect 5.9.2 Behavioural disturbance to fish, birds and marine mammals etc from physical presence of X X X X X X X 5.6.2 infrastructure and support activities 5.6.2.2 Collision risks to birds X X X 5.6.3 5.6.2.2 Collision risk to marine mammals, fish and large water column animals X X X 5.6.3 Barriers to movement of birds (e.g. foraging, migration) X X 5.6.2.1 Barriers to movement of fish and marine mammals X X X 5.6.2.1 Changes/loss of habitats from major alteration of hydrography or sedimentation ? X ? 5.4.2.2 Potential for effects on flora and fauna of produced water, saline discharges (aquifer water and X X X X X ? X 5.9.2 halite dissolution), and drilling discharges from wells and foundation construction EMF effects on sensitive species X X X X 5.6.2.5 February 2011 81 Environmental Report Offshore Energy SEA 2 Box 5.1 Sources of potentially significant effect Storage Wave Wave Topic farms farms 2 Section Oil & Gas Tidal Range Tidal Range CO Gas Storage Gas Storage Assessment Assessment Assessment Tidal Stream Tidal Stream Offshore Wind Wind Offshore The nature and use of antifouling materials ? X ? X 5.9.2 Accidental events - major oil or chemical spill X ?1 ?1 ?1 ?1 ? ?1 5.13.2.1 Accidental events - major release of CO2 X 5.13.2.1 SEA Topic Geology, substrates and coastal geomorphology Physical effects of anchoring and infrastructure construction (including pipelines and cables) on 5.4.2.1 X X X X X X X seabed sediments and geomorphological features (including scour) 5.4.2.2 Sediment modification and contamination by particulate discharges from drilling etc or re- X X X X X X X 5.9.2 suspension of contaminated sediment Effects of reinjection of produced water and/or cuttings and injection of CO2 X X X 5.9.2 Onshore disposal of returned drilling wastes – requirement for landfill X X X 5.10.2 5.4.2.1 Post-decommissioning (legacy) effects – cuttings piles, footings, foundations etc X X X X X X X 5.4.2.2 5.4.2.2 Changes to sedimentation regime and associated physical effects X X X 5.5.2 1 1 1 1 1 1 5.13.2.2 Accidental events - risk of sediment contamination from oil or chemical spills X ? ? ? ? ? ? 5.13.2.3 5.13.2.2 Accidental events – blow out impacts on seabed X X X 5.13.2.3 SEA Topic Landscape/seascape 5.8.2.4 Potential visual impacts and seascape effects of development including change to character X X X X X X X 5.8.3 SEA Topic Water environment Contamination by soluble and dispersed discharges including produced water, saline discharges (aquifer water and halite dissolution), and drilling discharges from wells and foundation X X X X X ? X 5.9.2 construction Environmental Report 82 February 2011 Offshore Energy SEA 2 Box 5.1 Sources of potentially significant effect Storage Wave Wave Topic farms farms 2 Section