Study Methods


The aims of the EIA are:

  • to gather information about the environment of the study area (Figure 3.1) and identify environmental constraints and opportunities associated with the area which may influence, or be affected by the proposed scheme;
  • to identify and incorporate into proposed scheme design, construction and operation, features and measures to avoid or mitigate adverse impacts and enhance beneficial impacts; and
  • to identify and assess predicted significant environmental impacts after mitigation has been applied.

This chapter discusses the approach and methods used to carry out the assessment and identifies aspects of the proposed development that have been subject to assessment.

Map showing the extent of the study area for the EIA
Figure 3.1 Study Area

Approach and Methods

Scope and Guidance

This EIA has been carried out in accordance with the Environmental Impact Assessment (Scotland) Regulations 1999 and Environmental Impact Assessment (Scotland) Amendment Regulations 2006. EIA is a requirement under the EIA Regulations. It also takes guidance from Volume 11 of the Design Manual for Roads and Bridges (DMRB) (Highways Agency, 1993); this was first published in 1993 and amended and updated by the Highways Agency, The Scottish Government, The Welsh Assembly Government and The Department for Regional Development Northern Ireland.

The DMRB provides guidance on the development of trunk road schemes including motorways and is applicable to this proposed scheme. Volume 11 of the DMRB specifically provides guidance on the environmental impact assessment of this type of scheme, including the level of assessment required at key stages of development and the requirements for reporting the environmental effects of such schemes.

Annex E of the Circular 8/2007 ‘The Environmental Impact Assessment (Scotland) Regulations 1999’ (Scottish Government, 2007) provides guidance on EIAs of trunk road projects. Although The Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2011 consolidated, updated and replaced Part II of the Environmental Impact Assessment (Scotland) Regulations 1999, Parts III and IV of the 1999 Regulations concerning Roads, Bridges and Land Drainage, remain extant. Consequently, the guidance contained in Circular 8/2007 in Annex E continues to apply and is relevant to the proposed scheme.

New DMRB guidance has been published recently (Interim Advice Note 125/15: Environmental Assessment Update, IAN125/15), but since the assessment was scoped prior to this, it has not been applied to the ES.


The scoping stage is generally a desk-based assessment that draws on readily-available sources of information to identify those features that can scoped out of an EIA because no significant effects are anticipated. It then assesses in detail those that are scoped in.

Detailed assessment

Detailed assessment is required where the potential for significant effects has been identified. This will usually involve site investigation to better understand the character and value of the resource, the magnitude of the impact and the mitigation required to minimise the impact.

The assessment covered in this report was undertaken between April 2013 and November 2016. The environmental topics covered by this assessment are those that were ‘scoped in’ in the Scoping Report (Scotland TranServ, 2013) as being considered to have significant impacts on environmental receptors. It identifies the likely impacts of the proposed scheme and assesses the residual impacts following implementation of mitigation measures.

The assessment approach has also taken into account further guidance as detailed below.

Best Practice Guidance used for Environmental Assessment
  • Environmental Impact Assessment (Scotland) Regulations 1999.
  • Environmental Impact Assessment (Scotland) Amendment Regulations 2006.
  • Scottish Planning Series: Planning Circular 8 2007: The Environmental Impact Assessment (Scotland) Regulations 1999, November 2007.
  • The Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2011.
  • Planning Advice Note (PAN) 1/2013: Environmental Impact Assessment, 2013.Circular 15/99 The Environmental Impact Assessment (Scotland) Regulations 1999, The Scottish Executive.
  • A Handbook on Environmental Impact Assessment – Guidance for Competent Authorities, Consultees and others involved in the Environmental Impact Assessment Process in Scotland, SNH 2013.
Water Environment
  • The SuDS Manual, CIRIA C753, 2015.
  • PPG1: General Guide to the Prevention of Pollution, SEPA.
  • PPG2: Above Ground Oil Storage Tanks, SEPA.
  • PPG4: Treatment and Disposal of Sewage where no Foul Sewer is Available, SEPA.
  • PPG5: Works and Maintenance in or near Water, SEPA.
  • PPG6: Working at Construction and Demolition Sites, SEPA.
  • PPG13: Vehicle Washing and Cleaning, SEPA.
  • PPG20: Dewatering of Underground Ducts and Chambers, SEPA.
  • PPG22: Incident Response – Dealing with Spills, SEPA.
  • PPG26: Safe Storage: Drums and Intermediate Bulk Containers, SEPA.
  • The Water Environment (Controlled Activities) (Scotland) Regulations 2011, as amended.
  • The Water Environment (Controlled Activities) (Scotland) Regulations 2011 (as amended): A Practical Guide, Version 7.2, March 2015.
  • Is your site right? (a 10-point checklist produced by SEPA).
  • SPP7: Planning and Flooding, Scottish Executive, 2004.
  • PAN 79: Water and Drainage, Scottish Executive, 2006.
  • WAT-SG-23 Good Practice Guide – Bank Protection, SEPA, 2008.
  • WAT-SG-25: Good Practice Guide – River Crossings, SEPA, 2010.
  • WAT-SG-26: Good Practice Guide – Sediment Management, SEPA, 2010.
  • WAT-SG-29: Good Practice guide – Construction Methods, SEPA, 2009.
Ecology and Nature Conservation
  • Guidelines for Ecological Impact Assessment in the UK and Ireland: Terrestrial, Freshwater and Coastal, Chartered Institute of Ecology and Environmental Management, 2016.
  • Ecological Impact Assessment, Jo Treweek 1999.
  • Biodiversity Impact, Helen Byron 2000.
  • National Planning Policy Guideline (NPPG) 14: Natural Heritage, 1999 The Scottish Government
Landscape and Visual Issues
  • Landscape and Visual Assessment Supplementary Guidance, Scottish Executive 2002.
  • Cost Effective Landscape: Learning from Nature, Scottish Executive, 1998.
  • Guidelines for Landscape and Visual Assessment, Landscape Institute and Institute of Environmental Management and Assessment, 2013.
  • Richards, J., 1999: Inverness District Landscape Character Assessment, Scottish Natural Heritage Review No. 114, 1999.
Policies and Plans
  • SPP1: The Planning System, The Scottish Government (November 2002).
  • NPPG 10: Planning and Waste Management, The Scottish Government (June 1996).
  • NPPG11: Sport, Physical Recreation and Open Space, The Scottish Government, 1996.
  • Scottish Planning Policy 15 SPP 15: Planning for Rural Development (2010).
  • NPPG 17: Transport and Planning, The Scottish Government, 1999.
  • NPPG18: Planning and the Historic Environment, The Scottish Government, 1999.

In accordance with DMRB Volume 11, consideration has been given to the following environmental factors:

  • Air Quality;
  • Cultural Heritage;
  • Disruption Due to Construction;
  • Ecology and Nature Conservation;
  • Landscape Effects;
  • Land Use;
  • Noise and Vibration;
  • Pedestrians, Cyclists and Community Effects;
  • Vehicle Travellers;
  • Road Drainage and the Water Environment;
  • Geology and Soils; and
  • Impact of Road Schemes on Policies and Plans.

A number of these topics have been ‘scoped out’ (see Section 4.4.) and this ES specifically focusses on Cultural Heritage (Chapter 5), Ecology and Nature Conservation (Chapter 6), Landscape Effects (Chapter 7) and Road Drainage and the Water Environment (Chapter 8) as well as an assessment of cumulative effects (Chapter 9). In line with current DMRB guidance, the assessment of impacts due to construction and consideration of policies and plans, where relevant, are also included within each topic chapter.

Assessment Methods

Impacts which occur during construction works, whether temporary or permanent, and impacts on policies and plans are considered within each environmental topic where appropriate.

Each assessment reported in the ES is structured as follows:

  • description of study area;
  • evaluation of baseline features;
  • impact assessment;
  • identification of mitigation, enhancement and monitoring measures;
  • significance of residual impacts following mitigation; and
  • summary of the assessment.

There may be slight differences in layout within the individual sections, as appropriate to the individual topic assessment.

Baseline Conditions

The specific assessment for each environmental subject has been undertaken in relation to a ‘baseline’. The ‘baseline’ normally reflects the existing situation and how this would change if the proposed scheme did not go ahead (i.e., the Do Nothing Scenario).

Baseline information has been collected through site visits and review of maps, data, records, information and reports obtained from statutory and non-statutory organisations (see Chapter 4: Consultation and Scoping) and a variety of field surveys.

Site visits were undertaken on several occasions during 2011 to 2016 by the Scotland TranServ / BEAR Scotland Environment Team to assess the baseline conditions and potential environmental risks from the proposed work.

The consultation process with statutory and non-statutory organisations is reported in Chapter 4.

Predicted Impacts and Determining the Significance of Environmental Effects

Predicted Impacts

The nature of predicted impacts arising from the proposed scheme has been described and in general an assessment of the level of significance of the impact (as described in Section for each effect determined as far as practical.

Impacts may also be wide-ranging in nature; they could result in direct or indirect, secondary, cumulative, short, medium or long-term, permanent or temporary, positive or adverse effects. These factors have also been taken into account.

Determining the Significance of Environmental Effects

The general criteria for assessing the significance of environmental effects are set out in detail in Volume 11 Section 2 Part 5 (HA 205/08) of the DMRB. Tables 3.2-3.4 are reproduced directly from this guidance for the convenience of the reader. Tables specific for each topic are also provided within each chapter.

There is no universally accepted definition of what constitutes a significant impact. It varies according to the environmental factor under consideration, the context in which the assessment is made and the background of the assessor. Much depends on the availability of data relating to existing environmental conditions and the value applied to these conditions.

The level of significance of impact has been defined in accordance with DMRB Volume 11, Section 2, Part 2. The approach combines the sensitivity of the environmental feature in question with the magnitude of impact, each having been assessed independently according to defined criteria. Sensitivity has generally been defined according to the relative importance of the feature or by the characteristics of the receptor. In the definition of magnitude of impact, consideration has been given to any legislative or policy standards or guidelines, and/or the following factors:

  • the degree to which the environment is affected, e.g. whether the quality is enhanced or impaired;
  • the scale of the development, e.g. the size of land area or number of receptors affected and degree of change from the existing situation;
  • the scale of change resulting from impacts; and
  • whether the effect is temporary or permanent.

Magnitude of Impact and Typical Criteria Descriptors

  • Loss of resource and/or quality and integrity of resource; severe damage to key characteristics, features or elements (Adverse).
  • Large scale or major improvement of resource quality; extensive restoration or enhancement; major improvement of attribute quality (Beneficial).
  • Loss of resource, but not adversely affecting the integrity; partial loss of/damage to key characteristics, features or elements (Adverse).
  • Benefit to, or addition of, key characteristics, features or elements; improvement of attribute quality (Beneficial).
  • Some measurable change in attributes, quality or vulnerability; minor loss of, or alteration to, one (maybe more) key characteristics, features or elements (Adverse).
  • Minor benefit to, or addition of, one (maybe more) key characteristics, features or elements; some beneficial impact on attribute or a reduced risk of negative impact occurring (Beneficial).
  • Very minor loss or detrimental alteration to one or more characteristics, features or elements (Adverse).
  • Very minor benefit to or positive addition of one or more characteristics, features or elements (Beneficial).
No change
  • No loss or alteration of characteristics, features or elements; no observable impact in either direction.

Typical Descriptors of the Significance of Effect Categories

Very large

Only adverse effects are normally assigned this level of significance. They represent key factors in the decision-making process. These effects are generally but not exclusively, associated with sites or features of international, national or regional importance that are likely to suffer a most damaging impact and loss of resource integrity. However, a major change in a site or feature of local importance may also enter this category.


These beneficial or adverse effects are considered to be very important considerations and are likely to be material in the decision-making process.


These beneficial or adverse effects may be important but are not likely to be key decision-making factors. The cumulative effects of such factors may influence decision-making if they lead to an increase in the overall adverse effect on a particular resource or receptor.


These beneficial or adverse effects may be raised as local factors. They are unlikely to be critical in the decision-making process but are important in enhancing the subsequent design of the project.


No effects or those that are beneath levels of perception, within normal bounds of variation or within the margin of forecasting error.

Significance Criteria for Cumulative Effects (DMRB Volume 11, Section 2, part 5)


Effects that the decision-maker must take into account as the receptor/resource is irretrievably compromised.


Effects that may become key decision-making issue.


Effects that are unlikely to become issues on whether the project design should be selected, but where future work may be needed to improve on current performance.


Effects that are locally significant.

Not significant

Effects that are beyond the current forecasting ability or are within the ability of the resource to absorb such change.

Mitigation Measures

The approach to mitigation measures adopted for this EIA is consistent with the guidance provided in Planning Advice Note (PAN) 1/2013 on EIA. Mitigation should be considered as a hierarchy ranging from prevention or avoidance of environmental effects, down to compensation for effects that cannot be remedied. The hierarchy is summarised below.

Mitigation Hierarchy


To prevent adverse environmental effects at source, for example, through choice of site or specification of construction equipment.


If adverse effects cannot be prevented, steps taken to reduce them through such methods as minimisation of cause of impact at source, abatement on site and abatement at receptor.


When effects remain that cannot be prevented or reduced, they are offset by remedial or compensatory actions. This can be provision of environmental improvements, opportunities for access and informal recreation, creation of alternative habitats and prior excavation of archaeological features.

The approach to the mitigation of adverse environmental impacts has been to avoid them wherever practicable. From the design outset, this has been achieved by considering how to prevent adverse effects at source, rather than relying on measures to mitigate the effects. Where it has not been possible to avoid impacts, measures have designed to minimise those impacts, such as landscaping and pollution prevention measures on site.

The Definition of Residual Effects

Residual impact sections within each chapter report the anticipated significance of impacts remaining following the application of the proposed mitigation identified in the chapter.