1.6 Environmental Impact Assessment methodology ​

1.6.1 Overview ​

1.6.1.1 This section presents an outline of the EIA methodology that has been employed for the Mona Offshore Wind Project in the preparation of the PEIR. The EIA for the Mona Offshore Wind Project describes the likely effects on the environment arising from the construction, operation and maintenance, and decommissioning of the Mona Offshore Wind Project. Where likely significant effects are predicted, it identifies mitigation to reduce the significance of these effects (where practicable).

1.6.2 Approach to EIA ​

1.6.2.1 The approach to determining the scope of the EIA to be included in an application for a Development Consent Order (DCO) can be broadly summarised as consisting of three main elements that take place prior to the submission of the application for the DCO and Environmental Statement:

• Scoping: To determine the issues to be addressed during the EIA process
• Consultation: Pre-application consultation in accordance with the 2008 Act (as amended), including production of a PEIR which forms the basis of statutory consultation
• Environmental Statement Preparation: Reporting on the EIA process, updating the information provided in the PEIR and continuing with design iteration and consultation.

1.6.2.2 The assessment of each topic (e.g. marine mammals, shipping and navigation etc.) forms a separate chapter of this PEIR. For each topic chapter, the following components are included:

• Identification of the study area for the topic-specific assessments
• Description of the planning policy and guidance context
• Summary of key consultation activity, including comments received in the Scoping Opinion
• Description of the environmental baseline conditions (including future baseline conditions)
• Presentation of the EIA, which includes:
  • Identification of the Maximum Design Scenario (MDS) for each impact assessment
  • Identification of likely impacts and assessment of the significance of identified effects
  • A description of the measures adopted as part of the Mona Offshore Wind Project to prevent, reduce or offset environmental effects
  • Where required, identification of any further measures required in respect of likely significant effects, together with consideration of any residual effects
  • Identification of any future monitoring which may be required
  • Assessment of any cumulative effects with other major developments, including those that are proposed, consented and under construction
  • Assessment of any transboundary effects (i.e. effects across state boundaries) is discussed further in section 1.6.8 of this document.

1.6.2.3 Inter-related effects (i.e. inter-relationships between environmental topics) are assessed in separate chapters (one for onshore and one for offshore) in the PEIR.

1.6.2.4 The approach to the principal components of the approach to EIA is described in further detail in the following sections.

1.6.3 Consultation and scoping ​

Scoping

1.6.3.1 Consultation on the proposed EIA methodology (including the Cumulative Effects Assessment (CEA) methodology and approach to assessing transboundary and inter-related effects) was undertaken at the EIA scoping stage. The Mona Offshore Wind Project Scoping Report (Mona Offshore Wind Ltd, 2022), which contained details of the proposed approach to EIA for each topic was submitted to the Secretary of State for BEIS in May 2022. The Applicant received the Scoping Opinion in June 2022 (The Planning Inspectorate, 2022). The Applicant met with stakeholders to discuss their feedback in more detail and to consider refinements to the Mona Offshore Wind Project ahead of formal consultation on the PEIR.

1.6.3.2 Consultation will continue throughout the lifetime of the Mona Offshore Wind Project.

Statement of Community Consultation

1.6.3.3 The Applicant has prepared a Statement of Community Consultation (SoCC), which sets out how it plans to consult local communities on the Mona Offshore Wind Project. The Applicant will conduct its consultation in line with the SoCC. The Applicant has consulted on the scope of the SoCC and will consult on the contents of the SoCC with each of the local authorities in whose area the Mona Offshore Wind Project is situated.

1.6.3.4 In Wales, community/town councils are also prescribed consultees and will be notified and consulted by the Planning Inspectorate and the Applicant as part of the pre-application consultation.

1.6.3.5 Because of the location of the Mona Offshore Wind Project, the local authorities which the Applicant has consulted with are:

• Conwy County Borough Council
• Denbighshire County Council
• Flintshire County Council
• Gwynedd Council
• Powys County Council
• Wrexham County Borough Council.

Public consultation

1.6.3.6 The Applicant carried out a phase of public consultation between 7 June and 3 August 2022. Over the consultation period, a number of events took place. These included an online event (in the form of a webinar), public exhibitions and pop-up events which allowed those interested in, or affected by, the Mona Offshore Wind Project to view the information provided. A second non-statutory consultation phase was undertaken in Autumn 2022 on the potential substation locations.

1.6.3.7 At these events (whether online or in person), members of the public were able to view the latest information on the Mona Offshore Wind Project, including maps and diagrams illustrating the proposed infrastructure. They were able to speak directly with members of the Mona Offshore Wind Project team and ask any questions or raise any concerns they had. Participants had the opportunity to complete a feedback form.

1.6.3.8 At the end of the non-statutory consultations, feedback was collated and considered and has informed future development of the consultation and EIA processes, where appropriate. All feedback will be comprehensively presented within the Consultation Report, which will be submitted as part of the application.

1.6.3.9 Further information on the Mona Offshore Wind Project and its consultation is published on the project website:

• English
• Cymraeg

Topic-specific consultation

1.6.3.1 The Applicant is facilitating the Evidence Plan Process for the Mona Offshore Wind Project. The process provides an opportunity for stakeholders to advise on proposals at an early stage to help mitigate environmental effects. As part of this, a Steering Group has been established, as well as EWGs to discuss topic-specific issues with relevant stakeholders. The Steering Group consists of the following members:

• Natural Resources Wales (NRW)
• Natural England
• Joint Nature Conservation Committee (JNCC)
• The Marine Management Organisation (MMO)
• The Planning Inspectorate.

1.6.3.1 EWGs have been established for the following topics:

• Physical processes, benthic ecology and fish and shellfish ecology (members include: NRW, Natural England, JNCC, MMO, The Wildlife trusts (TWT) and the Isle of Man government)
• Marine mammals (members include: NRW, Natural England, JNCC, MMO, TWT and the Isle of Man government)
• Offshore ornithology (members include: NRW, Natural England, JNCC, MMO, TWT, Royal Society for the Protection of Birds (RSPB) and the Isle of Man government)
• Onshore ecology (member include Conwy County Borough Council, NRW, RSPB, Denbighshire County Council, north Wales wildlife trust and Welsh Government)
• Site selection (Conwy County Borough Council, Denbighshire County Council).

1.6.3.1 In addition to the Evidence Plan Process, the Applicant is also facilitating a Maritime Navigation Engagement Forum (MNEF) to enable the Applicant to regularly update stakeholders on plans and progress of the Mona Offshore Wind Project, and for stakeholders to express views or concerns on the impacts of the Mona Offshore Wind Project for discussion and, where possible, resolution. Four pre-PEIR MNEF meetings have been held, in November 2021, May 2022, October 2022 and January 2023.

1.6.3.1 The Applicant is committed to consultation with commercial fisheries stakeholders. MarineSpace provides the role of Company Fisheries Liaison Officer (CFLO) on behalf of the Applicant. Consultation has been undertaken with key local and regional fisheries stakeholders since June 2021, to date.

1.6.3.1 An Archaeology and Heritage Engagement Forum has been established in order to consult with the MMO, Historic England, CADW and the Royal Commission on the Ancient and Historical Monuments of Wales on the potential impacts that the Mona Offshore Wind Project may have on onshore and offshore historic environment.

1.6.3.1 The Applicant has undertaken consultation for seascape, landscape and visual resources with SNCBs and the applicable local councils on the representative viewpoint locations which formed the basis for the site survey work and photography on which the EIA is based.

1.6.4 Design envelope approach ​

1.6.4.1 The Mona Offshore Wind project EIA process has employed a maximum design scenario (MDS approach, also known as the ‘Rochdale Envelope’ approach. The MDS approach allows the EIA process to be conducted on the basis of a realistic 'worst case' scenario (i.e. the maximum project design parameters) which is selected from different design and construction scenarios. For each of the impacts assessed within the topic chapters, the MDS is identified from the range of potential options for each parameter within the project description of the PEIR.

1.6.4.2 For example, where several wind turbine options are included in the design, then the assessment of the Mona Offshore Wind Project has been based on the wind turbine type considered to have the greatest impact. This may be the wind turbine type with the largest footprint, the greatest tip height or the largest area of seabed disturbed during construction, depending upon the topic under consideration. By identifying the MDS for any given impact, it can therefore be concluded that the impact (and therefore the effect) will be no greater for any other design or construction scenario than that assessed for the MDS. By employing the MDS approach, the Applicant retains some flexibility in the final design of the Mona Offshore Wind Project, but within certain maximum parameters, which are fully assessed in the EIA. The final Mona Offshore Wind Project design will be selected after development consent has been granted, in line with the parameters stated in the project description within the Environmental Statement.

1.6.5 Mitigation and the iterative design process ​

1.6.5.1 During the EIA process, potential environmental effects are taken into account as part of the ongoing iterative design process. The process of EIA has therefore been used as a means of informing the design, with the Applicant making design decisions that mitigate impacts on the environment (referred to as measures adopted as part of the Mona Offshore Wind Project). The assessments within the PEIR therefore include a range of measures that have been designed to reduce or prevent significant adverse effects arising.

1.6.6 Assessment of effects ​

1.6.6.1 The Mona Offshore Wind Project has the potential to create a range of 'impacts' and consequent 'effects' with regard to the physical, biological and human environment. The term 'impact' is defined as a change that is caused by an action. The term 'effect' is defined as the consequence of an impact. For example, the laying of an inter-array cable (action) results in seabed disturbance (impact), with the potential to disturb benthic habitats and species (effect).

1.6.6.2 For each of the impacts assessed in this PEIR, a magnitude has been assigned. The magnitude of an impact considers the spatial extent, duration, frequency and reversibility of the impact from the construction, operations and maintenance, or decommissioning phase of the Mona Offshore Wind Project.

1.6.6.3 Receptors are defined as the physical or biological resource or human user group that could be affected by the Mona Offshore Wind Project impacts. These receptors are identified through available data and baseline studies that have been reviewed in the preparation of this PEIR. In defining the sensitivity for each receptor, the vulnerability, recoverability and value/importance has been taken into consideration.

1.6.6.4 The overall significance of an effect is evaluated by considering the magnitude of the impact alongside the sensitivity of receptor. Each chapter defines the approach taken to the assessment of significance. Unless set out otherwise within the chapter, the matrix approach shown in Table 1.3 has been adopted as a guide.

Table 1.3: Matrix used for the assessment of the significance of the effect

1.6.7 Cumulative Effect Assessment ​

1.6.7.1 Cumulative effects are defined as those that result from incremental changes caused by other reasonably foreseeable projects, alongside the project in question (IEMA, 2017). The CEA therefore considers the likely effects arising from the Mona Offshore Wind Project alongside the likely effects of other projects, plans and activities in the vicinity of the Mona Offshore Wind Project, based on the information available in the public domain. Cumulative effects are considered within each topic chapter of the PEIR.

1.6.7.2 The ISAA for the Mona Offshore Wind Project considers in-combination effects as set out under the Conservation of Habitats and Species Regulations 2017 (as amended). These are similar to cumulative effects but are defined as the combined effect of the Mona Offshore Wind Project, with the effects from a number of different projects, plans and activities, on the integrity of European Sites designated for their nature conservation value. In-combination effects are presented separately within the ISAA.

1.6.8 Transboundary effects ​

1.6.8.1 Transboundary effects arise when impacts from a project within one State affect the environment of another state(s). Transboundary effects have been considered in each topic chapter of the PEIR, based on the outcome of the transboundary screening.

1.6.9 Inter-related effects ​

1.6.9.1 The 2017 EIA Regulations require consideration of the indirect and secondary likely significant impacts of the Mona Offshore Wind Project. For example, the separate impacts of noise and habitat loss may have an effect upon a single receptor such as marine mammals or the impact of noise and visual effects on people living nearby.

1.6.9.2 The approach presented in the PEIR has been developed in line with the Planning Inspectorate Rochdale Envelope Advice Note (Advice Note Nine) (Planning Inspectorate, 2018) which states: “Inter-relationships consider impacts of the proposals on the same receptor. These occur where a number of separate impacts, (e.g. noise and air quality), affect a single receptor such as fauna.”