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Screening and Scoping

Screening for EIA
  What is scoping?
  Why do scoping?
The Scoping Process
  Identifying stakeholders, consultees and key players
  Interim scoping report
  Gathering information about the project
  Carrying out a desk study: establishing the zone of influence
  Selecting ecological features and issues requiring detailed assessment
  Conclusions of the scoping process

Screening for EIA

2.1 Screening19 is the determination of whether or not an EIA is needed and is a formal requirement under the EIA Regulations. EIA is a mandatory requirement for projects listed in Schedule 1 of these Regulations. It is also required for types of projects that meet the criteria for Schedule 2 development and are likely to have significant environmental effects (i.e. as defined using the selection criteria in Schedule 3 of the Regulations.

2.2 A formal Screening Opinion may be sought from the competent authorities concerning the need for an EIA; alternatively, the proponent may decide to carry out an EIA in any case. When a competent authority receives an application for consent without an accompanying Environmental Statement (ES), and there appears to be a possibility that it is for a Schedule 1 or 2 development, the authority must adopt a Screening Opinion (unless a pre-application Screening Opinion or a screening direction from the relevant Secretary of State has already been adopted).

2.3 Under the EIA Regulations, there is provision for a competent authority to request ecological or other environmental information if it considers that an ES is inadequate. When an EIA is not required, there may also be circumstances where a proponent can be required to provide supporting ecological information. An EcIA will often provide the competent authority with the information that it requires to satisfy itself that wider biodiversity issues have been addressed (to achieve consistency with Article 10 of the Habitats Directive).

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What is Scoping?

2.4 ‘Scoping is the process of determining the content and extent of matters that should be covered in the environmental information to be submitted to a competent authority or other decision making body’20.

2.5 The minimum requirement is that competent authorities must provide a scoping opinion if requested by a developer. The scoping opinion should identify the content and extent of the information to be elaborated and supplied by the developer to the competent authority. The Directive also allows Member States to make scoping a mandatory part of their EIA procedure. (see reference 20 above).

2.6 The process of scoping is essential to all EcIAs. It helps to clarify key issues and to promote dialogue with consultees and other stakeholders concerning key ecological issues and proposed methods for survey, evaluation and assessment. It also ensures that the proponent is aware of the likely issues and has an understanding of the expected costs.

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Why do Scoping?

2.7 The key benefits of scoping include:

  • early stakeholder identification, engagement, input and identification of issues of concern;
  • an assessment focused on key, likely significant impacts on known biodiversity, their inter-relationships and sensitivities;
  • clear terms of reference for all engaged in the EcIA, including an understanding of the criteria that will be used to evaluate the significance of their findings;
  • early identification of existing data and data gaps;
  • justification for the exclusion of issues from the EcIA; and
  • early identification of the need for seasonally dependent surveys so that they can be accommodated in the schedule of work.

2.8 It is essential to consider relevant legislation, regulations (Annex 1), plans and policies at an early stage, as they may have a bearing on the required scope of investigations, how impacts should be interpreted and/or the criteria that need to be used for determining significance.

2.9 Experience has shown that where major projects have failed to seek a scoping opinion serious problems have often emerged later on. Good practice usually involves early consultation with statutory consultees and other stakeholders. This is advisable in the case of most major projects as a failure to seek a scoping opinion can lead to problems. A scoping opinion summarises the specific advice of the competent authority concerning the required coverage and content of the ES for a particular application. In preparing a scoping opinion, the UK competent authority is required to consult with the proponent and with relevant statutory consultees. Statutory consultees can play an important role in providing contextual information and advice on any legal/statutory requirements and good practice. The preparation of a scoping opinion does not preclude the competent authority from asking for further information at a later stage in the EIA process, but it does help to reduce the likelihood that this will happen.

2.10 In the absence of a formal scoping opinion, it will usually fall to the proponent’s ecologist to advise the proponent on the scope of ecological information and investigations likely to be required, having also consulted with other stakeholders, if possible.

2.11 Various national, regional and local policies require projects to achieve biodiversity enhancements not simply to avoid negative impacts. For example the UK Government and Devolved Administrations have, in Our seas – a shared resource21 set out a series of high level marine objectives, which under ‘Living within environmental limits’ states “Biodiversity is protected, conserved, and, where appropriate, recovered, and loss has been halted”. The scoping process can provide a good, early opportunity and a mechanism for ecologists and other relevant specialists to work together to achieve these objectives and lays the foundations for the whole consultation and assessment process.

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The Scoping Process


2.12 Scoping should be seen as a flexible, adaptive and iterative process, usually based on preliminary consultations, literature searches, site-visits and preliminary ecological surveys. There is no set formula, but it should include at a minimum the elements identified in Box 2. If scoping commences at an early stage in the assessment, it may be necessary to delay the completion of some of these elements, until adequate information has become available. More information on each of the stages described in Box 2 is provided in subsequent sections.

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Box 2: Key Components of Scoping

The proponent’s ecologist should:

  • obtain information about the project from the proponent or their engineers/designers, including the spatial extent, timing, frequency and duration of the project;
  • carry out a desk study to gather relevant information on the proposed development site, the study area and identify data gaps;
  • identify project activities likely to cause damage, stress, disturbance or impact on ecosystems processes;
  • establish the zone of influence or identify the need for modelling to determine the zone of influence;
  • evaluate experience gained from previous projects and their outcomes;
  • identify other significant projects/proposals and any related activities, e.g. access roads, within the zone of influence of the project/proposal that could result in significant cumulative or in-combination effects or opportunities for enhancement etc;
  • identify stakeholders, consultees and all ecologists who should be engaged, and establish a consultation strategy;
  • identify opportunities for enhancing biodiversity and delivering national biodiversity objectives;
  • produce a draft scoping report as a basis for further consultation with the competent authority, statutory consultees and others engaged in the consultation strategy;
  • refine the scope of the assessment based on feedback on the scoping report;
  • continue to refine the scope - exclude potential impacts that are no longer considered likely to be significant and include newly identified impacts that are likely to be significant; and
  • ensure that the final scoping report provides the terms of reference for the remainder of the EcIA.

Through consultation with key stakeholders the proponent’s ecologist should:

  • identify relevant legislation, regulations, policies and plans including Strategic Environmental Assessments, Marine Spatial Strategies and Plans, Shoreline Management Plans etc.
  • indentify those activities that require licensing authorisation before they can go ahead;
  • develop an understanding of the ecological context based on existing ecological information, data gathering, literature searches, site visits and any baseline studies already carried out;
  • determine criteria for selecting ecological features to be included in the assessment, based on their value, using measures explained in Chapter 4;
  • identify those ecological resources reaching the threshold value that could be affected by the project;
  • identify the factors affecting the integrity of the relevant ecosystems and the conservation status of relevant habitats and species;
  • identify conservation objectives of designated ecological features;
  • identify ecological features likely to be significantly affected and therefore requiring further study, and explain the criteria used;
  • identify for coastal and estuarine projects key information from any relevant River Basement Management Plans;
  • consider potential sources of cumulative and in-combination effects;
  • agree details of proposed survey and research methodologies including temporal and spatial considerations;
  • confirm the criteria that will be used to assess ecological value; and
  • consider potential avoidance, mitigation/compensation and enhancement opportunities.

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Identifying Stakeholders, Consultees and Key Players

2.13 At an early stage, the competent authority and the proponent’s ecologist must review the requirements for ecological input and any other specialist skills that are needed to undertake the EcIA. In undertaking this review, consideration should be given as to who will finally advise the competent authority on the ecological consequences and possible environmental liability resulting from the proposal.

2.14 Consideration should also be given to the important role of statutory and non-statutory ecological consultees in providing site-specific data, contextual information and local expertise. There should be early discussions with them regarding possible alternative(s) that are likely to cause the least ecological damage or result in the greatest benefits. Such consultation will facilitate evaluation of the scope and methods of any investigations that may be needed to consider alternatives.

2.15 Where there are potentially significant impacts on biodiversity, landscapes and seascapes known to provide benefits to local communities it is not only good practice, but important, to engage in consultation with them. Consideration should be given to the best methods for the engagement of stakeholders and the terms of reference for doing so, to enable an open process to take place with no surprises.

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Interim Scoping Report

2.16 It is advisable to circulate the draft scoping report (or letter) to statutory consultees and relevant voluntary bodies and interested parties for comment. Well-run scoping workshops can provide all major stakeholders with an opportunity to discuss a proposal and reach consensus on the scope of the assessment. This can considerably reduce consultation time and avoid delays caused by stakeholders requesting additional survey or other work at a later stage. All agreements on the scope of ecological survey work should be confirmed in writing by the parties concerned, at as early a stage as possible; ideally, this should be before initiation of the proposed survey and assessment work.

2.17 There should also be preliminary discussions with key stakeholders regarding:

  • potential strategies to avoid or minimise any negative impacts;
  • to determine possible ways of compensating for any residual impacts; and
  • to define possible enhancement measures.

This will enable the ecologist to concentrate on those approaches most likely to meet with stakeholders’ approval.

2.18 When determining whether the effects of a proposal are likely to be significant, competent authorities should always have regard to the potential for cumulative and in-combination effects with any existing or approved project. Cumulative impact assessment is discussed in Chapter 5. The detailed approach to be taken should be agreed between all parties concerned during scoping.

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Gathering Information about the Project

2.19 The first step is to review proposed activities and identify those likely to cause negative or positive impacts to biodiversity and/or the landscape:

  • what are the proposed activities?
  • where, when, how and for what period of time will they take place?
  • are they permanent and if not, how long will they last?
  • what direct or indirect biophysical changes are they likely to cause?

2.20 The information likely to be required about a project is summarised in Box 3. For projects requiring an EIA reference should be made to the schedules in the EIA Regulations; these specify the information that should be included in an ES. Examples of activities that may generate impacts on biodiversity are given in Box 5.

 Box 3: Information about the Project

Effective EcIA requires the following information:

  • location, size, extent, temporal and spatial organisation of infrastructure and activities;
  • lifetime of the project including decommissioning;
  • activities likely to cause impacts to ecological features and resources during construction, operation and decommissioning, their timing, duration, location, extent and magnitude, e.g. discharges (type, volume, range), construction activities, etc. (see Box 5);
  • zone of influence of the activities;
  • other developments within the zone of influence for which consent has been or is likely to be granted;
  • pathway for emissions (e.g. water, soil or air) and the receiving environment;
  • best and worst case operating conditions including construction practices for safeguarding existing biodiversity; and
  • activities/proposed measures designed to deliver biodiversity enhancements.

To define the baseline conditions that are expected to occur at the time when the development takes place and to address cumulative effects, it is necessary to consider:

  • environmental trends;
  • completed developments; and
  • other developments for which consent has been granted.

Further information about the definition of baseline conditions and cumulative impact assessment is included in Chapter 5.

To assess the impacts of alternatives the following information will be needed:

  • alternative sites;
  • alternative designs;
  • alternative processes including construction methods and phasing; and
  • alternative means of meeting the objectives of the project.

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Carrying out a Desk Study: Establishing the Zone of Influence

2.21 Activities will differ throughout the lifetime of a project therefore, it is important to define those associated with the construction, operation (best and worst-case operating conditions), decommissioning and restoration phases. The location of infrastructure and the distribution of the related activities are best addressed by the provision of appropriate scale charts, maps and plans. Note that positions should be geo-referenced to latitude and longitude and the datum(s) used (e.g. WGS84) should be specified. Areas and resources affected (including their physical extent) and their responses should be identified. It is important to ensure that these include all impacts, however remote from the project site, to identify the zone of influence (see Boxes 4 and 5) of the project.

2.22 The zone of influence should be continually reviewed and amended as the project evolves. Where appropriate, the zone of influence should be identified with the aid of hydrodynamic models that can take changes in factors such as, the pattern of currents, temperature, salinity, sediment and other water quality parameters into account. These models will show the potential extent of a change in the existing conditions and are a useful tool for assessing the likely impacts on the communities or species in a particular area. If inadequate information is available to properly define the zone of influence, this should be acknowledged.


Box 4: Considerations relevant to establishing baseline conditions for the ecological features and resources within the zone of influence

Designated sites

  • Are there any features (sites/species) designated for their nature conservation value that fall within the zone of influence at any time of the year?
  • Does the proposal affect any areas likely to be designated in the foreseeable future such as Marine Protected Areas?
  • Is there any policy presumptions in favour of habitat protection/creation/restoration in the area?

General ecological considerations

  • What ecological features at or above the defined threshold of value are likely to occur within the zone of influence?
  • What are their distribution and status elsewhere for comparison?
  • What were their historical distributions, status and management compared with the present?
  • Is anything known about the key drivers influencing distribution and abundance of the feature(s)?
  • What are their scales of variation, vulnerability and likely exposure to the project?
  • What are the key activity periods for species and ecological processes; are there seasonal variations in distribution, abundance and activity?
  • Is the area used by migratory species of birds, fish and/or sea mammals?
  • How significant is the area for fisheries/shellfisheries?
  • How significant is the area for specific stages in the life cycle of protected species?
  • Are there any features whose disappearance would have significant consequences for others?
  • Is there a likelihood of local extinction?
  • Are there any other projects within the same area or timeframe that may contribute to cumulative or in-combination effects?

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Box 5: Examples of activities likely to generate impacts alone or in combination

Preliminary activities prior to the main construction contract

Ground and seabed investigations:

  1. geotechnical e.g. geological/engineering; e.g. drilling of wells (for offshore gas storage, oil, etc.); boreholes, geological sampling, etc.; and
  2. geo-environmental e.g. seabed contamination, groundwater sampling, gas monitoring/detection, general seabed sediment analysis.

Construction phase

  • Access and travel on/off-site, including temporary access routes for construction vehicles and vessels.
  • Acoustic disturbance from construction activities.
  • Anchoring and related scour from lines and chains.
  • Assembly areas for components of construction.
  • Blasting, e.g. for navigation channels.
  • Construction of structures and hard surfaces.
  • Demolition operations.
  • Dredging and smothering.
  • Drilling operations.
  • Disposal of dredged materials/drilling waste.
  • Environmental incidents and accidents (e.g. spillages, noise and discharges) and potential pollution from fuels, oils, drilling materials, construction materials.
  • Seabed, seismic and excavation works.
  • Infrastructure links between an offshore location and terrestrial networks (e.g. cables and pipelines).
  • Lighting.
  • Positioning and subsequent removal of site offices/compounds/vessels and final site clear away after construction.
  • Release of contaminants from disturbed sediments.
  • Removal or disturbance of sediments, or disruption of sediment transport.
  • Storage areas for construction materials.
  • Structural works for construction and engineering.
  • Structural works to existing structures, including conversions.
  • Coastal vegetation clearance.
  • Seabed and water column disturbance.
  • Noise and vibration from piling activities.

Occupation/Operational phase

  • Access to site (both route and means).
  • Alteration in wave action/currents/sediment transport.
  • Damage to mitigation work (including accident or vandalism).
  • Drainage.
  • Runoff containing contaminants or sediments.
  • Continuing small-scale spills of oil or fuel.
  • Implementation of design and habitat management (type and location).
  • Incremental disturbance due to the presence of people, vehicles and their activities (e.g. increased public access and recreational pressures).
  • Site operation and management (e.g. maintenance operations, industrial processes generating discharges, etc.).

Decommissioning and Restoration

  • Blasting.
  • Changes in wave action, sediments and hydrodynamics.
  • Disturbance or removal of contaminated sediment.
  • Recycling of materials and re-use or disposal.
  • Removal of ancillary developments including culverts in coastal areas.
  • Removal or demolition of disused structures that may be used by roosting waterfowl.
  • Removal or neglect of structures that might cause pollution if they fail.
  • Sediment disturbance.

Potential non-standard operations (e.g. one-off incidents and accidents).

  • Oil and chemical spills.
  • Military testing.
  • Drilling.

(Based on Oxford 2001)11

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2.23 Contextual information is essential to confirm the spatial and temporal scope of the study. Such information may be available from the ecological consultees and in local and national Biodiversity Action Plans. Information is also available from websites such as the ‘Multi-Agency Geographical Information for the Countryside’ (, the ‘Marine Life Information Network’ ( and other sources such as Charting Progress22. Adequate time and resources should be allowed to undertake such vital contextual research. These references will also provide the information required in order to value ecological receptors (see Chapter 4).

2.24 At the scoping stage it can be difficult to establish the full extent of changes likely to be caused by a project. If so, it is better to adopt the precautionary principle to ensure that the study incorporates all areas where impacts could occur through the life of the project and consequently it is important to define and record:

  1. the project area (the footprint of the development);
  2. the measures needed to determine the overall zone or area of influence of a project (area likely to be affected by the development): and
  3. the study area (area chosen for investigation).

Developments in the marine environment have the potential to affect key physical processes over wide areas and can lead to impacts beyond the immediate footprint of the project. It is therefore necessary on some occasions to consider the application of numerical modelling techniques as an aid to defining the zone of influence, see Box 6.

Box 6. Numerical modelling as an aid to defining the zone of influence

Numerical models of coastal and estuarine processes are widely employed for a variety of purposes. They are, for example, used extensively as management tools by the Environment Agency (England and Wales). Consequently, proven models already exist for certain areas of the UK coast. In addition, some consultants, and academics, possess modelling systems that can be generally applied subject to suitable calibration and validation data from the area of interest. However, all such existing models will require modification (e.g. the inclusion of mathematical representations of additional processes) depending upon the nature of the projects to be investigated in relation to a specific development. This has both time and cost implications that are relevant to project planning.

Typically, numerical models of coastal and estuarine environments are constructed around a flow module that represents the relevant water mixing processes and simulates and predicts temporal and spatial variations in flow velocity and water level in the area of interest. This information serves as input to drive associated modules that represent features such as sediment transport, morphodynamics and water quality. By identifying the likely area over which changes in such factors are likely to occur as a result of a proposed development, numerical models can help to better define the zone of influence. In addition, the information they provide on the predicted extent and magnitude of potential changes can be employed by ecologists when assessing the likely impact of the potential changes on ecological structure and function.

The construction and application of numerical models of coastal and estuarine processes is a specialised field unfamiliar to many ecologists1 and which may not take account of the features of interest i.e. the specific ecosystem. Consequently, care should be taken in interpreting the model output especially if the model used is unable to demonstrate an acceptable level of agreement between the simulations and predictions it produces and actual field measurements of the parameters of interest. In such cases model output should be treated with caution and careful consideration should be given to defining the degree of uncertainty associated with any predictions made.

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Selecting Ecological Features and Issues Requiring Detailed Assessment

2.25 As it is impossible to investigate all issues in detail, further study should concentrate on those issues most likely to generate significant ecological impacts (negative/positive). This is consistent with the EIA Regulations, which only require investigation of likely significant effects. The rationale and criteria used to select features for more detailed study (and others excluded from further investigation) should be agreed and documented during scoping.

2.26 Issues to consider when selecting ecological features for further investigation include:

  1. Whether the feature or resource is sufficiently valuable for an impact to be significant in terms of biodiversity and/or social/community and/or economic values; legal protection needs to be considered separately. A clear rationale should be developed for deciding the thresholds above which features and resources should be subject to more detailed consideration. This should be based on the value of features, measured as described in Chapter 4. This will enable all those engaged in the assessment and decision making process to understand the reasoning behind the scope of the investigations. Policy considerations will influence the criteria that will be appropriate for determining the threshold in any particular case.
  2. Whether the feature or resource is likely to be subject to a significant negative impact.
  3. Whether the competent authorities have specific WFD, biodiversity, landscape or other legislative duties that are beyond the conventional approach of designated sites and protected species e.g. marine spatial planning, integrated coastal zone management and flood risk.

2.27 These issues are discussed in more detail in Chapters 4 and 5, where guidance is provided on methods for identifying important sites, habitats or species and determining whether impacts are significant. See also the example in Box 7.

Box 7: Example illustrating factors to consider when defining the zone of influence of a proposed offshore windfarm and a port development.

Offshore windfarm

The construction of a windfarm may have a variety of local effects such as scour around individual monopiles, but it also has the potential for more widespread impacts, such as:

  • changes to sediment movement and potentially to coastal morphology depending upon proximity to the shore and the method of protecting transmission cables;
  • direct construction impacts e.g. direct removal of benthic biodiversity;
  • damage to spawning grounds within and adjacent to the infrastructure, through vibration and noise disturbance;
  • obstruction of migration routes of mobile species, especially fish, birds and marine mammals;
  • impacts on seabird populations and on the dynamics of seabird colonies;
  • impacts of vibrations/electromagnetic interference on fish, birds and marine mammals; and
  • disturbance to coastal vegetation and ecological features resulting from requirements for additional infrastructure and land-links, (e.g. piers and jetties) together with possible needs for safeguarding their integrity (e.g. armouring a cable); and
  • provision of substrate for colonisation by native or non-native species.

Port development

The construction of a new port or similar development will not only involve new infrastructure, direct habitat losses and displacement of waterfowl, but also more widespread impacts such as dredged channels, which may impact on subtidal species or assemblages (e.g. reefs). The impacts of these changes largely relate to the physical processes within the water body or sediment cell, although these activities may have consequences for the benthic assemblage and some mobile species of the area, particularly in non-developed areas. These may include:

  • disruption to sediment pathways;
  • changes to tidal propagation and the extent and duration of mudflat and saltmarsh exposure;
  • changes in water quality with increased turbidity;
  • potential release of contaminants in the seabed that may be transported elsewhere by the currents;
  • changed wave regimes;
  • changes in the local pattern of currents;
  • changes to accretion and erosion processes at localities away from the main point of impact that change the functionality of mudflat, saltmarsh and sub-tidal communities; and
  • long-term changes in sedimentation and sediment availability.

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Conclusions of the Scoping Process

2.28 The results of scoping are presented as a formal report or letter to the competent authority. This is fundamental to any project that requires detailed ecological survey, particularly where stakeholder-input is essential in defining terms of reference acceptable to all parties. For EIAs, a scoping report/letter is often used as the basis for applying for a formal scoping opinion from the competent authority.

2.29 It is important to recognise that the proposed scope of an EcIA may change following the preparation of a scoping report/letter. This may be in response either to concerns identified by statutory or other consultees, or to changes in the project’s design or available environmental information. It is good practice to report the final scope of the assessment within the EcIA report (or ES) to the competent authority.

2.30 Once the initial scoping work is complete, it should be possible to identify any additional information required to predict impacts more fully. This may involve updating existing data and is covered in Chapter 3. The geographic coverage and timing of further ecological studies to be undertaken during the EcIA should be agreed at the scoping stage. These can be revised later if necessary, as progressively more information becomes available through the assessment process.

2.31 Terms of reference for additional studies are based on:

  • information on ecological resources within the zone of influence;
  • the timeframe for all phases of the project; and
  • information gaps/survey needs that should be addressed in order to assess potential impacts and their significance.

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