East Coast 400 kV Overhead Line Upgrade Environmental Impact Assessment Report Volume 2 | Main Text January 2021 Scottish Hydro Electric Transmission plc Inveralmond House 200 Dunkeld Road Perth PH1 3AQ Tel: +44 (0)1738 456 000 www.ssen-transmission.co.uk
i CONTENTS
LIST OF ABBREVIATIONS IV 1 INTRODUCTION 1-1 1.1 Overview of the Proposed Development 1-1 1.2 Background to the Proposed Development 1-1 1.3 Previous Environmental Assessment 1-2 1.4 Legislative Requirements 1-2 1.5 Contents of the Environmental Impact Assessment Report 1-3 1.6 EIA Quality 1-3 1.7 Notifications 1-4 2 CONSIDERATION OF ALTERNATIVES 2-2 2.1 Introduction 2-2 2.2 Development Considerations 2-2 2.3 Alternatives 2-2 2.4 Design evolution 2-4 2.5 Summary 2-4 3 DESCRIPTION OF THE PROPOSED DEVELOPMENT 3-1 3.1 Introduction 3-1 3.2 The Proposed Development 3-1 3.3 Limits of Deviation 3-2 3.4 Construction Programme 3-2 3.5 Construction Environmental Management 3-2 3.6 Construction Practices and Phasing 3-4 3.7 Construction Employment and Hours of Work 3-14 3.8 Construction Traffic 3-15 3.9 Operation and Management of the Transmission Connection 3-15 4 EIA CONSULTATION AND SCOPE 4-1 4.1 Introduction 4-1 4.2 Pre-Application Consultation 4-1 4.3 Scoping 4-1 4.4 Gatecheck 4-2 4.5 Potentially Significant Issues 4-3 4.6 Scoped-out Issues 4-3 5 METHODOLOGY 5-1 5.1 Introduction 5-1 5.2 Identification of Baseline 5-1 5.3 Assessment of Likely Significant Environmental Effects 5-2 5.4 Identification of Mitigation Measures 5-4 5.5 Cumulative Effects 5-4 5.6 Assumptions and Limitations 5-7 6 HYDROLOGY, HYDROGEOLOGY AND SOILS 6-1 6.1 Introduction 6-1 6.2 Assessment Methodology and Significance Criteria 6-1 6.3 Baseline Conditions 6-8 6.4 Issues Scoped Out 6-16 6.5 Assessment of Effects, Mitigation and Residual Effects 6-17 6.6 Summary 6-23
ii 7 BIODIVERSITY 7-1 7.1 Introduction 7-1 7.2 Assessment Methodology and Significance Criteria 7-1 7.3 Baseline Conditions 7-11 7.4 Issues Scoped Out 7-20 7.5 Assessment of Effects, Mitigation and Residual Effects 7-26 7.6 Summary 7-41 8 CULTURAL HERITAGE 8-1 8.1 Introduction 8-1 8.2 Assessment Methodology and Significance Criteria 8-1 8.3 Baseline Conditions 8-8 8.4 Issues Scoped Out 8-12 8.5 Assessment of Effects, Mitigation and Residual Effects 8-12 8.6 Summary 8-25 9 NOISE AND VIBRATION 9-1 9.1 Introduction 9-1 9.2 Assessment Methodology and Assessment Criteria 9-2 9.3 Baseline Conditions 9-12 9.4 Issues Scoped Out 9-12 9.5 Assessment of Effects, Mitigation and Residual Effects 9-13 9.6 Summary 9-23 10 ELECTRIC AND MAGNETIC FIELD EFFECTS 10-24 10.1 Introduction 10-24 10.2 Assessment Methodology 10-24 10.3 Baseline Conditions 10-27 10.4 Issues Scoped Out 10-29 10.5 Assessment of Effects, Mitigation and Residual Effects 10-30 10.6 Summary 10-34 11 CUMULATIVE EFFECTS 11-1 11.1 Introduction 11-1 11.2 In-Combination Effects 11-1 11.3 Effect Interactions 11-1 12 SCHEDULE OF ENVIRONMENTAL MITIGATION 12-2 12.1 Introduction 12-2
OTHER VOLUMES VOLUME 1 – NON-TECHNICAL SUMMARY VOLUME 3 – FIGURES VOLUME 4 – TECHNICAL APPENDICES
iii LIST OF ABBREVIATIONS
AAAC All Aluminium Alloy Conductor AC Alternating current ACAS Aberdeenshire Council Archaeology Service ACSR Aluminium Conductor Steel Reinforced ASNW Ancient Semi-Natural Woodland ATV All-terrain vehicle AWI Ancient Woodland Inventory BGN Background Noise BGS British Geological Survey BoCC Birds of Conservation Concern BPA Bonneville Power Administration BPP Badger Protection Plan BSI British Standards Institution CAR Controlled Activity Regulation CDM Construction Design and Management CEMP Construction Environmental Management Plan CIEEM Chartered Institute of Ecology and Environmental Management CRA Collision Risk Assessment CSRSG Central Scotland Raptor Study Group CTMP Construction Traffic Management Plan DC Direct current DECC Department of Energy and Climate Change DWPA Drinking Water Protected Areas EcIA Ecological Impact Assessment ECoW Environmental Clerk of Works ECU Energy Consents Unit EHO Environmental Health Officer ELF Extremely low frequency EIA Environmental Impact Assessment EIA Report Environmental Impact Assessment Report EMF Electric and Magnetic Field EPS European Protected Species EPZ Equipotential Zones ESO Electricity System Operator EZoI Ecological Zone of Influence FISA Forestry Industry Safety Accord FLS Forestry and Land Scotland GEMP General Environmental Management Plans GDL Gardens and Designed Landscapes GRR Geotechnical Risk Register GWDTE Groundwater Dependent Terrestrial Ecosystems
iv HER Historic Environment Record HES Historic Environment Scotland HEPS Historic Environment Policy for Scotland ICNIRP International Commission on Non-Ionizing Radiation Protection IEF Important Ecological Feature IEMA Institute of Environmental Management & Assessment JNCC Joint Nature Conservation Committee Km Kilometre kV Kilovolt LNCS LOCAL Nature Conservation Sites LNR Local Nature Reserve LOD Limit of Deviation NETS SQSS National Electricity Transmission System Security and Quality of Supply Standards NESBReC North East Scotland Biological Records Centre NERSG North East Scotland Raptor Study Group NNR National Nature Reserve NLS National Library of Scotland NPF3 National Planning Framework 3 (Scotland) NETS SQSS National Electricity Transmission System Security and Quality of Supply Standards NSR Noise Sensitive Receptor NOA Network Options Assessment NRPB National Radiological Protection Board NSR Noise sensitive receptors NTS Non-Technical Summary NVC National Vegetation Classification OHL Overhead Line OPGW Optical Ground Wire PAN Planning Advice Note PAWS Plantation on Ancient Woodland Sites PHE Public Health England PLHRA Peat Landslide Hazard and Risk Assessment PKHT Perth and Kinross Heritage Trust PPG Pollution Prevention Guidance PWS Private Water Supply RSPB Royal Society for the Protection of Birds SAC Special Areas of Conservation SBL Scottish Biodiversity List SBN Scoping Briefing Note SEPA Scottish Environment Protection Agency SHE Scottish Hydro Electric SM Scheduled Monument SNH Scottish Natural Heritage (now NatureScot) SNRHE Scottish National Record of the Historic Environment
v SPT Scottish Power Transmission SPP Species Protection Plan SSSI Site of Special Scientific Interest TAN Technical Advice Note T&FRSG Tayside and Fife Raptor Study Group WSI Written Scheme of Investigation
vi 1 INTRODUCTION
1.1 Overview of the Proposed Development Scottish Hydro Electric Transmission plc (SHE Transmission) is a wholly-owned subsidiary of the SSE plc group of companies. SHE Transmission (hereafter referred to as ‘the Applicant’) owns and maintains the electricity transmission network across the north of Scotland, and holds a licence under the Electricity Act 1989 (hereafter referred to as the ‘Electricity Act’) to develop and maintain an efficient, co-ordinated and economical system of electricity transmission. Due to the growth in renewable electricity generation in the north and north-east of Scotland, upgrade of the transmission network is required to provide the necessary increase in transmission capacity. The Applicant is applying for consent under Section 37 (s37) of the Electricity Act to upgrade approximately 168 kilometres (km) of an existing 275 kV overhead line (OHL), connecting existing substations at Kintore, Fetteresso, Alyth T-Junction and the Applicant’s licence boundary with Scottish Power Transmission (SPT), as shown on Figure 1.1: Location Plan and Overview, to enable operation at 400 kV (hereafter referred to as the Proposed Development). This would involve replacing the existing conductors and their associated fittings and insulators. Deemed planning permission under Section 57(2) of the Town and Country Planning (Scotland) Act 1997 (the Town and Country Planning Act) is also sought for associated works such as access track upgrades. The Proposed Development is described in full in Chapter 3: Description of the Proposed Development of this document.
1.2 Background to the Proposed Development The requirement for the Proposed Development is necessary to fulfil the statutory and licence obligations on the Applicant as the onshore transmission licence holder in the north of Scotland. These obligations relate to developing the electricity transmission network to provide adequate transmission capacity and to provide connections to customers in the north of Scotland who wish to connect to and use the transmission system to participate in the national wholesale electricity market.
As a result of increasing renewable electricity generation such as onshore windfarms, in conjunction with the recent increases in smaller, background generation, the Applicant is progressing a number of transmission reinforcement schemes in the north of Scotland to provide the necessary transmission capacity in accordance with the National Electricity Transmission System Security and Quality of Supply Standards (NETS SQSS). The need for a high voltage electricity transmission network is also included within the current National Planning Framework 3 (NPF3)1 as “new and / or upgraded onshore electricity transmission cabling of or in excess of 132 kilovolts, and supporting pylons”. The NPF3 confirms that the Proposed Development is required to support the delivery of an enhanced high voltage electricity transmission grid which is identified as vital in meeting national targets for electricity generation, statutory climate change targets and the security of energy supply. This reinforcement has also been recommended to ‘Proceed’ by the Electricity System Operator (ESO) through the Network Options Assessment (NOA) in 2017/182, 2018/193 and 2019/204.
1 National Planning Framework 3: monitoring report (2019). Available at: https://www.gov.scot/publications/national-planning-framework-3-monitoring- report/pages/3/ (Accessed: 16/06/2020) 2 National Grid (2018). Network Options Assessment 2017/2018. Available at: https://www.nationalgrideso.com/document/106481/download
3 National Grid (2019). Network Options Assessment 2018/2019. Available at: https://www.nationalgrideso.com/document/137321/download
4 National Grid (2020). Network Options Assessment 2019/2020. Available at: https://www.nationalgrideso.com/document/162356/download
1-1 The Proposed Development is technically and economically justified to meet the future requirements of the Applicant and the wider UK transmission system.
1.3 Previous Environmental Assessment An Environmental Impact Assessment (EIA) was undertaken in 2013 for upgrading this section of OHL and is documented within the East Coast 400 kV Reinforcement Project Environmental Statement (April 20135), hereafter referred to as the ‘Previous ES’. The Previous ES supported a s37 application for a wider scope of work beyond that of the Proposed Development, including the upgrade of the OHL north of Kintore, diversion of a section of OHL and the construction and alteration of substations. However, this application was subsequently withdrawn prior to determination due to changes in scope, project need and timescales, and the additional scope of works aspects have been progressed separately. With regards to the OHL upgrade works, the Previous ES considered re-insulating only and assumed replacement of the conductors only if they were damaged. The Previous ES assessed the environmental topics discussed within this EIA Report (and further topics, given the wider scope of work) and identified the adverse and beneficial predicted significant environmental effects. The OHL works were assessed as having limited potential environmental effects and none were considered to be significant.
The only identified potential long-term significant effect related to radio and television interference at nearby residences from the increased electric field strength of the OHL. The assessment concluded that this would be limited to reception of medium and long wave (AM) radio signals; however, reception of digital TV, digital radio and FM radio would be unaffected. Mitigation was proposed in the form of the provision of digital radios for affected residences, where necessary. More recently, works have been undertaken from 2016 to 2017 to replace the earthwire of the OHL Route (hereafter referred to as the ‘earthwire replacement works’). These works did not require an EIA as they were undertaken under the Applicant’s permitted development rights, however relevant assessments, such as ecology and cultural heritage, were undertaken by the Applicant to ensure the potential environmental impacts were minimised.
1.4 Legislative Requirements The Electricity Works (Environmental Impact Assessment) (Scotland) Regulations 2017 (hereafter referred to as the EIA Regulations) contain two schedules. Schedule 1 lists projects where Environmental Impact Assessment (EIA) is mandatory. Schedule 2 lists projects where EIA may be required ’where proposed development is considered likely to give rise to significant effects on the environment by virtue of factors such as its nature, size or location’.
The Proposed Development falls within Schedule 1 of the EIA Regulations, as it meets the criteria of paragraph (4) of Schedule 1. An EIA is therefore mandatory and an EIA Report will accompany the s37 application.
A request for a Scoping Opinion was made to the Scottish Ministers under Regulation 12 of the EIA Regulations in May 2020. A Scoping Report (Appendix 4.1: Scoping Report) was submitted to support the request, which sought input from the Energy Consents Unit (ECU), statutory and non- statutory consultees regarding the information to be provided within this EIA Report. The Scoping Opinion of the Scottish Ministers was issued in August 2020 confirming the scope of the EIA Report. Further details of this are contained in Chapter 4: EIA Consultation and Scope, and accompanying appendices.
5 Scottish Hydro Electric Transmission (SHET) (2013). East Coast 400Kv Reinforcement Project Environmental Statement. 1-2 1.5 Contents of the Environmental Impact Assessment Report The EIA Report consists of the following volumes: · Volume 1 – Non-Technical Summary; · Volume 2 – Main Text; · Volume 3 – Figures; and · Volume 4 – Technical Appendices.
1.6 EIA Quality In line with Regulation 5 (5) of the EIA Regulations, the EIA Report and all technical assessments have been undertaken by a suitably qualified project team. A statement outlining the relevant expertise / qualifications for the discipline leads is provided as follows: · Sarah McMonagle (EIA Project Manager): Member of the Institute of Environmental Management and Assessment and Chartered Environmentalist, Sarah has worked in environmental consultancy for 15 years and is experienced in undertaking EIAs and other environmental studies. She is a specialist in the energy sector; having a strong track record of electricity transmission, renewables and conventional power station developments across Scotland. · Thomas Goater (Ecology and Ornithology Lead): Thomas Goater (Ornithology Lead): Member of the Chartered Institute for Ecology and Environmental Management (CIEEM), MSc in Aquatic Biodiversity and BSc in Marine Ecology. Thomas has over 13 years of experience working as an ecological consultant. He has worked on various development projects including overhead powerlines, grid connections, onshore wind farms and power station life-extensions throughout Scotland and northern England, from feasibility and inception to construction phase support and post-construction monitoring. The geographic distribution of these projects has involved survey and assessment of a wide variety of ecological sensitivities ranging from rare and vulnerable raptors such as golden eagles, hen harrier and osprey to overwintering waterfowl and wading birds. Thomas has been working alongside Jenny Downie (Ecology Lead), Associate member of CIEEM; BSc (Hons) Zoology; NatureScot bat roost licence. Jenny’s technical expertise lies in botany and protected species, with experience in identifying plant communities of increased conservation importance and evaluating impacts; including through the Habitats Regulations Appraisal process. Jenny has worked on various developments including large infrastructure projects in the power and energy sectors; as well as bridge schemes, road schemes and flood relief schemes. · Kevin Mooney (Cultural Heritage Lead): Member of the Chartered Institute for Archaeologists, BSc in Archaeology and Fellow of the Society of Antiquaries Scotland. Kevin has over 13 years of experience as a heritage professional advising and undertaking mitigation against archaeological and heritage issues. Kevin has had experience working on a number of utility schemes from both the archaeological contractor and consultant side. He has previously managed the archaeological mitigation work associated with the upgrade of the network of overhead electrical power lines near Killin, Perthshire, and is currently involved in the upgrades to overhead lines near Carsphairn, Dumfries and Galloway and Dalmally in Argyll and Bute. He is also involved in delivering environmental assessments for a number of substations including those at Stornoway and Argyll. · Phil Jenn (Hydrology and Hydrogeology Lead): Phil has eight years’ experience working on a broad range of land and water projects, including numerous Environmental Impact Assessment projects for wind farm developments of 10MW+, including Section 36 wind farm developments. His experience spans the water environment and peat aspects of EIA such hydrological assessment, water quality assessment, peat stability assessment, with responsibilities including planning and leading peat surveys, private water supply surveys, watercourse crossings surveys, in addition to undertaking a broad range of desk studies, data analyses and interpretation, report
1-3 writing including authoring EIA Report Chapters and Technical Appendices, and data presentation, including GIS mapping. · Eric Donnelly (Noise and Vibration Lead): Corporate member of the UK Institute of Acoustics with an engineering honours degree from Strathclyde University. Eric is the team leader of Wood Group’s Noise & Vibration Team. Eric specialises in noise impact assessments for industrial projects including existing and proposed wind farms, electrical substations and other electrical infrastructure. Since joining Wood, he has been involved in over 100 wind farm projects including the largest onshore developments in Europe. Eric joined Wood as the Noise and Vibration Team Leader in 2003, following five years as a Noise and Vibration Consultant and Team Leader in Scottish Power’s Technology Division. Eric has undergone training from Glasgow Caledonian University for the presentation of evidence at public enquiry. · Martin Šafránek (Electric and Magnetic Frequencies Lead): Martin is an Electrical Engineer who has 32 years’ experience as an Overhead Line Engineer with specialist knowledge and skills in all aspects of design, construction and commissioning of distribution and transmission lines at voltages including 10 kV, 33 kV 132 kV, 220 kV 330 kV and 400 kV. He has extensive experience in the management of overhead line projects including feasibility studies, design, tendering, project co-ordination, material procurement and testing. He’s also external lecturer at Newcastle University – Electrical Engineering. · Euan Brierley (Forestry and Arboriculture Lead): Euan Brierley PhD, MICFor is a chartered forester with over 30 years of experience of natural resource management covering inter- disciplinary land use of soil, plants and water, in the UK and overseas. The primary focus of his land management has been forestry and woodland management, including the urban forest, but includes other semi-natural habitats and agriculture and horticulture. Euan has published books and papers around his research and consultancy in the use of woody vegetation, from forestry and energy crops, for bioenergy. Euan is a former chair of the examination board of the Institute of Chartered Foresters and received the president’s award for meritorious service in 2010.
IEMA Quality Mark The coordination, compilation and procedural review of the EIA Report are in line with the requirements outlined by the Institute of Environmental Management & Assessment (IEMA)’s Quality Mark scheme. As with environmental assessment, good practice in the preparation of the EIA Report is defined in a number of sources, with more specific issues covered by EIA Report review checklists. Many of these checklists are very detailed and go to some length. In terms of widely applicable and practical guidance, the IEMA Quality Mark scheme provides best practice review criteria against which all EIA reports are evaluated.
Best practice guidance as set out within the IEMA Quality Mark scheme requires identification of key limitations affecting the EIA process and the resultant EIA Report. Limitations in methods are identified and discussed particularly where this is likely to affect the outcomes of the assessment. As with any environmental assessment, there will be elements of uncertainty. Where relevant these are identified and reported, together with a statement on any implications on the assessment and conclusions.
1.7 Notifications Notice will be served to the relevant planning authorities, in this case Perth & Kinross Council, Angus Council and Aberdeenshire Council, of the application to the Scottish Ministers for consent under s37 of the Electricity Act. In accordance with the Electricity (Applications for Consent) Regulations 1990, and Regulation 14 of the EIA Regulations, the application and this EIA Report will be advertised in the following newspapers: · Press & Journal;
1-4 · The Courier; and · Edinburgh Gazette.
There is a temporary relaxation of the requirement for displaying paper copies of the EIA Report at a named public place under the temporary coronavirus modifications to the electricity works regulations6. In accordance with the temporary modifications, electronic versions of the application including this EIA Report and its supporting volumes are available to download from SHE Transmission’s website: www.ssen-transmission.co.uk/projects/east-coast-onshore-400kv-ohl-upgrade/
The EIA Report can also be viewed via the ECU’s website: www.energyconsents.scot A digital version of the Non-Technical Summary is available at the link below. This presents a summary of the key information within this EIA Report alongside interactive maps and images. Should you wish to view the digital Non-Technical Summary, please visit: https://storymaps.arcgis.com/stories/6e60baac2f0d48608e92a3fe00b020b0 This EIA Report is available in other formats if required. For details, including costs, please contact: Louise Anderson Community Liaison Manager
6 The Electricity Works (Miscellaneous Temporary Modifications) (Coronavirus) (Scotland) Regulations 2020 1-5 2 CONSIDERATION OF ALTERNATIVES
2.1 Introduction The overall objective of the Proposed Development is to reinforce the existing transmission network to relieve capacity limitations and to provide for additional capacity for new generation connections. In accordance with Regulation 5(2)(d) and Schedule 4, paragraph 2 of the EIA Regulations, this chapter outlines the reasonable alternatives studied by the Applicant, which are relevant to the Proposed Development and its specific characteristics. The chapter also describes the main reasons for the option chosen, taking into account the effects of the Proposed Development on the environment.
2.2 Development Considerations The Applicant has obligations under section 9 of the Electricity Act to ‘develop and maintain an efficient, co-ordinated and economical system of electricity transmission'. The Applicant, as a licence holder under the Electricity Act, 'when formulating proposals to generate, transmit, distribute or supply electricity' is required, under Schedule 9 to: · “have regard to the desirability of preserving natural beauty, of conserving flora, fauna and geological or physiographical features of special interest and of protecting sites, buildings and objects of architectural, historic or archaeological interest”; and · “do what [it] reasonably can to mitigate any effect which the proposals would have on the natural beauty of the countryside or on any such flora, fauna, features, sites, buildings or objects”.
Under the terms of the transmission licence, the Applicant is obliged to comply with the NETS SQSS7, which provides the criteria for the planning and design of the transmission system. The NETS SQSS requires the Applicant to provide a transmission connection capable of withstanding single circuit faults without loss of supply and without disconnection of generation stations. Furthermore, the Construction (Design and Management) Regulations 20158 (CDM Regulations) require that the design aims to minimise hazards and reduce risks across the whole project lifecycle. Taking account of these obligations, the Applicant has considered technical, economic and environmental factors in evaluating the alternatives for the Proposed Development, with the aim of identifying a solution that meets the objectives of the Proposed Development which is 'technically feasible and economically viable' and 'which causes the least disturbance to the environment and to the people who live, work, visit and recreate within it'.
2.3 Alternatives The EIA Regulations require the Applicant to report upon the reasonable alternatives that were studied and the main reasons for the choice of the development, taking into account the environmental effects. The following alternatives have been considered during project development: · The “Do Nothing” Scenario; · New 400 kV OHL; and · Refurbish and Upgrade existing 275 kV OHL to 400 kV.
“Do-Nothing Scenario” The “do-nothing” scenario assumes that no other options are considered as reinforcement and the section of the transmission network forming part of this application would remain operational at a voltage of 275 kV.
7 National Electricity Transmission System Security and Quality of Supply Standard, Version 2.4, (2019). Available at: https://www.nationalgrideso.com/codes/security- and-quality-supply-standards?code-documents (accessed 05/06/2020) 8 The Electricity Works (Environmental Impact Assessment) (Scotland) Regulations (2017). Available at: http://www.legislation.gov.uk/ssi/2017/101/regulation/5/made (accessed 05/06/2020) 2-2 The upgrade to the transmission network in the north of Scotland is necessary due to the growth in renewable electricity generation requiring an increase in transmission capacity. Therefore, a “do- nothing” scenario would result in a significant network capacity deficit. This would not support the Applicant’s ability to meet their licence requirements, in respect of the planning and operation criteria, as required by NETS SQSS. Furthermore, without the transmission capacity increase future renewable energy generating developments in the region would be constrained by a lack of suitable grid connection. This would therefore impact Scotland’s carbon reduction targets and commitment to net zero emissions by 2045. The network would be at risk of potentially huge transmission constraints, through being unable to convey the generation connected to it, resulting in significant operational cost to constrain generation. Additionally, this would also make any future reinforcement of the network expensive and difficult due to the network being highly constrained resulting in high construction outage costs. The “do nothing” scenario is not considered a sustainable development option, resulting in insufficient capacity in the network and a failure to meet the generation and supply demands. It would be inconsistent with the Applicant’s licence obligations to develop and maintain an efficient, coordinated and economic electricity system, which on balance causes the least disturbance to the environment and to the people who live and work within it.
New 400 kV OHL A new 400 kV OHL from Kintore to a suitable point in the SPT area was considered. The potential environmental effects associated with the removal of the existing towers, in combination with the introduction of a new OHL route, would not provide the most efficient, coordinated, economic or technical solution for the capacity requirement on the north of Scotland transmission network. The additional time required to undertake studies to identify a suitable route corridor and alignment as well as construct the new OHL and dismantle the existing OHL would increase costs and delay the provision of additional transmission capacity.
The alternative of constructing a new 400 kV OHL was therefore discounted.
Refurbish and Upgrade existing 275 kV OHL to 400 kV The option of refurbishing and upgrading the existing OHL was based upon re-using the existing tower assets, as this could be achieved and avoided additional cost, time and potential impacts of installing new assets. Whilst the existing steel lattice towers can be utilised for future reinforcement, a technical and asset review was required to understand the ability for the existing conductors, insulators and earthwire to be used at a nominal voltage of 400 kV. Giving consideration to the asset condition, in combination with the long-term requirement to maintain the assets when operating at increased voltages, the review focussed on two approaches: · Re-insulate the 275 kV double circuit OHL from substations at Kintore to the Applicant’s licence boundary with SPT to 400 kV operation; or · Re-conductor and reinsulate 275 kV double circuit OHL from substations at Kintore to the Applicant’s licence boundary with SPT to 400 kV operation. The review confirmed that the approach of re-conductoring and reinsulating the OHL from the substation at Kintore to the Applicant’s licence boundary should be selected, as this approach provides the most coordinated, economic and efficient option and avoids piecemeal replacement and further disruption through undertaking re-conductoring at a later date. The alternative of only re- insulating the OHL would likely require additional work to be undertaken at a later date to operate at 400 kV, which would potentially introduce additional environmental impacts. Re-conductoring and re-insulating provides the best value to the consumer, reduces disruption to the public, reduces constraints to the transmission network and avoids the potential environmental impacts of rebuilding the OHL route.
2-3 The approach to re-insulating part of the OHL was discounted as the increase in network capacity would only be achieved in part. This would not make any meaningful reduction in system operation costs as the network constraints around the border with SPT would not be addressed. In addition, to re-insulate the remaining extent of the OHL in the future would result in costly re-mobilisation, construction works and additional length of time required for temporary access arrangements during the works.
2.4 Design evolution Conductor choice has been influenced by the consideration of potential environmental effects as part of the iterative design process, notably potential noise effects on residential receptors. Alternative conductor types and insulators technologies have been considered and the current proposals are presented in Chapter 3: Description of the Proposed Development.
2.5 Summary The Applicant has considered a number of alternatives in determining the key parameters of the Proposed Development. The “do nothing” scenario (i.e. no reinforcement to the existing 275 kV network) would result in a significant network capacity deficit due to the substantial growth in current and expected electricity generation in the north of Scotland and is therefore not considered to be a sustainable development option.
Alternative technical options have been considered as part of the proposal, with the decision taken to both re-conductor and reinsulate the existing OHL to minimise additional costs, disruption and environmental effects when compared to the other options.
The Proposed Development is described in full in Chapter 3: Description of the Proposed Development.
2-4 3 DESCRIPTION OF THE PROPOSED DEVELOPMENT
3.1 Introduction This chapter provides a description of the Proposed Development. The Proposed Development consists of upgrading approximately 168 km of OHL between Kintore (north-west of Aberdeen) Tower 559R’s tie in with Kintore substation and the Applicant’s Licence Boundary at Blairingone (east of Stirling) mid-span between towers 33 and 34, hereafter referred to as the OHL Route. The OHL Route, as shown in Figure 1.1: Location Plan and Overview is comprised of approximately (from north to south): · 32 km between tower 559R’s tie in with Kintore substation and Fetteresso substation; · 67 km between Fetteresso substation and Alyth T-junction; and · 69 km between Alyth T-junction and the Applicant’s licence boundary with SPT (hereafter referred to as mid-span between towers 33 and 34), near Blairingone.
3.2 The Proposed Development A s37 consent is being sought for an overhead line upgrade to operate at 400 kV and is described in more detail in Section 3.4. The key elements of the Proposed Development are: · replacement of conductors, insulators and fittings on the existing steel lattice towers; · where required, tower condition works including steelwork and tower leg foundation work to strengthen the existing steel lattice towers; and · height extensions to a maximum of 73 existing steel lattice towers to maintain the required operational ground clearances following the replacement of conductors and insulators.
In addition to the above, the works would also involve re-sagging of the existing Optical Ground Wire (OPGW) (i.e. the ‘earthwire’ on top of the tower). Associated works required to facilitate the Proposed Development would include vegetation clearance, access track upgrades, temporary site compounds, and temporary measures to protect the road, rail and water crossings. Deemed planning permission under the Town and Country Planning Act is also sought for these works. Consent for felling within the existing operational corridor is already in place; the size of the area for vegetation clearance is variable and dependent on tree species and heights in line with Forestry Industry Safety Accord (FISA) Safety Guide 804 – Electricity at work: Forestry9 guidance. The increase in clearance to vegetation, required as a result of the increased OHL voltage from 275 kV to 400 kV, is approximately 1 m either side of the OHL, and it is this increased area within areas of forestry that forms part of the Proposed Development. Appendix 3.1 Forestry discusses the forestry management requirements of the Proposed Development in more detail. To achieve mandatory clearance distances as a result of the proposed voltage upgrade approximately 7 ha of permanent forestry loss is anticipated; this includes an element of resilience felling which would be permitted as part of the existing 275 kV operational corridor, and is therefore an over-estimate. The more precise area will be recalculated following the completion of an on-going detailed Resilience Survey and a Compensatory Planting Plan will be prepared and agreed with Scottish Forestry. In addition, there is the potential requirement for temporary felling of a further 14 ha, which would be subsequently restocked.
9 FISA (2013). FISA Safety Guide 804 – Electricity at work: Forestry. Available at: https://ukfisa.com/Safety/Safety-Guides/fisa-804 3-1 The Proposed Development interfaces with the following existing and proposed substations as shown in Figure 1.1: Location Plan and Overview and also Figure 5.1: Cumulative Developments. All proposed works described below are being progressed separately and do not form part of this EIA or application for consent: · the proposed Kintore 400 kV substation extension, Aberdeenshire, and tie-in of the existing Kintore to Fetteresso double-circuit 275 kV OHL Route into this new substation extension. Consent was granted by Aberdeenshire Council in 2015 (Application reference: APP/2015/2520). However, due to a change in the site layout, a revised application is currently being progressed in parallel to the Proposed Development and is the subject of a separate planning application made by the Applicant under the Town and Country Planning (Scotland) Act 1997, as amended, submitted in July 2020 and pending determination (Application reference: APP/2020/1437). Tie-in of the existing Kintore to Fetteresso double-circuit 275 kV OHL Route into this new substation extension is also the subject of a separate application under s37 of the Electricity Act, as amended, submitted in July 2020 and pending determination (Application reference: ECU00002100). As part of the diversion works, two existing towers on the OHL Route Towers 558 and 559 would be removed and replaced with Towers 558R and 559R. The OHL diversion into Kintore 400 kV substation extension will operate at 400 kV following completion of the Proposed Development; · the existing Fetteresso 132 / 275 kV substation, Aberdeenshire. Minor works will be required at this substation to replace the existing 132 / 275 kV transformers with 132 / 400 kV transformers as part of the wider East Coast 400 kV upgrade; and · the proposed Alyth 275 / 400 kV substation, Perth and Kinross. Consent was granted by Perth and Kinross Council in July 2020 (Application reference: 19/01747/FLN). The substation wil be commissioned initially at 275 kV in 2023 but then upgraded for operation at 400 kV by October 2026. The tie-in of the existing double-circuit 275 kV OHLs into this substation is the subject of a separate application (Application reference: ECU00001952) and was approved by Scottish Ministers in April 2020.
3.3 Limits of Deviation A Limit of Deviation (LOD) defines the maximum extent within which a development can be built. As the majority of the Proposed Development comprises replacement of conductors, earthwire, insulators and fittings, a LOD is not required for these aspects of the work as the existing tower positions remain unchanged. A vertical LOD is however required in the case of the towers requiring height extensions to maintain operational ground clearances. The proposed tower height increases, as detailed in Table 3-1, have been determined on the basis of technical considerations, including engineering analysis of conductor performance under different operating conditions and weather conditions. It is possible that further engineering analysis at the detailed design stage might alter the required height increases, therefore a vertical LOD parameter is sought to allow a height increase of up to 10% of the existing tower heights.
3.4 Construction Programme It is anticipated that the OHL reinforcement works would commence in January 2023 (subject to approvals being granted), which would allow completion by October 2026. The detailed construction programme is subject to change as the design progresses and is subject to statutory consents and wayleaves being granted.
3.5 Construction Environmental Management All works will be done in accordance with the following:
3-2 General Environmental Management Plans
General Environmental Management Plans (GEMPs) have been developed by the Applicant. The following GEMPs are considered relevant to this project and are provided in Appendix 3.2 – SHE Transmission plc GEMPs: · Oil storage and refuelling; · Soil management; · Working in or near water; · Working in sensitive habitats; · Working with concrete; · Watercourse crossings; · Waste management; · Contaminated land; · Private water supplies; · Forestry; · Dust management; · Biosecurity on land; · Restoration; and · Bad weather.
Species Protection Plans Species Protection Plans (SPPs) have been developed by the Applicant and have been agreed with NatureScot10 (formerly Scottish Natural Heritage (SNH)). The following SPPs are considered relevant to this project and are in Appendix 3.3 – SHE Transmission plc SPPs: · Badger; · Bat; · Otter; · Red squirrel; · Bird; · Water vole; and · Pine marten.
CEMP A Construction Environmental Management Plan (CEMP) will be prepared and implemented by the Principal Contractor. This document would detail how the Principal Contractor would manage the site in accordance with all commitments and mitigation detailed in this EIA Report, statutory consents and authorisations, and industry best practise and guidance. Chapter 12: Schedule of Mitigation provides a schedule of the mitigation measures included in this report.
The CEMP would also reference the aforementioned GEMPs and SPPs. The implementation of the CEMP would be managed on-site by a suitably qualified and experienced Environmental Clerk of Works (ECoW), with support from other environmental professionals as required.
10 Formerly Scottish Natural Heritage, who rebranded to NatureScot in August 2020. Their statutory functions remain unchanged. 3-3 3.6 Construction Practices and Phasing
Phase 1 - Enabling Works Site Compounds It is currently anticipated that a minimum of three main compound areas will be required to facilitate construction works, the location of which would be confirmed by the successful Principal Contractor(s). In addition, it is likely that a ‘rolling’ arrangement for the provision of small sub yards, offices and welfare facilities would be required at convenient positions throughout the route, each for a short period of approximately four to six weeks duration to supply the work within each local section. The sub yards would be fed from the bulk delivery site. The use of smaller multiple yard sites would minimise the quantity and lengths of journeys required to supply to and recover from each work area.
The obtaining of any necessary planning consent or other authorisations required for the site compounds would be the responsibility of the successful Principal Contractor(s). Access Arrangements
Access would be required to each tower for delivery of fittings, fixtures, working platforms and plant. Access requirements to each tower would depend on the tower type and the operations required at the tower.
The indicative proposed access routes to each tower location are illustrated in Figure 3.1: Overhead Line Route and Construction Access Routes. Existing tower access routes utilised by the Applicant’s operation and maintenance teams and that which was used for the earthwire replacement works would be used whenever possible. Many individual tower sites would be accessible from public roads and farm tracks and in such circumstances normal site vehicles such as 4x4 Hiab wagons, transit vans, 4x4 pickup trucks, quad bikes and tractors would be utilised.
Where there are no public roads or farm tracks, should ground conditions permit, it may be possible in dry weather for the vehicle types indicated above to gain access to certain sites without causing ground surface damage. If damage is likely it may be necessary to undertake access upgrades to allow the use of the above vehicles, or alternatively to use specialist low ground bearing pressure vehicles. Access upgrades and protection can be undertaken in a number of ways. The preferred method for each site would be selected by the successful Principal Contractor(s) based on the suitability to withstand expected construction loads, cause the least environmental damage and be installed / recovered at the lowest cost.
The range of construction access options likely to be considered include: · installation of temporary metal or plastic roadway panels (e.g. Trakway); · installation of temporary stone roads on a geo-textile fabric base; · patching of existing accesses (for light use only); or · use of specialised low ground bearing pressure vehicles.
Temporary Roadway Panels Metal or plastic interlocking roadway panels (e.g. Trakway, Terra Firma or similar) can be installed over existing access or to form new access for the duration of construction works. Metal panels are also used at winch and tensioner positions to form Equipotential Zones (EPZs) (see paragraph 3.4.20) to protect against induced voltages from adjacent lines or lightning strike running along the conductors during stringing operations.
3-4 The delivery / installation vehicle would travel to the site loaded with panels and may also pull a trailer loaded with additional panels. The panels are usually unloaded and laid individually directly from the delivery / installation vehicle using the Hiab crane device mounted on the vehicle. The first panels would be laid onto the access then the wagon would drive onto the panels and advance along the access installing additional panels to extend the ‘road’ as it proceeds. Temporary Stone Roads Temporary stone roads on a geo-textile fabric base may be used in locations where heavier construction vehicles require access to tower locations. All temporary stone roads would be removed and reinstated on completion of construction. Patching of Existing Accesses
Patching of existing accesses can be carried out as required where existing access is otherwise suitable for use without protection, e.g. where traffic is light or using low bearing pressure vehicles only. Suitable materials can be brought to the work area in standard vans or pickup trucks.
Specialist Low Ground Bearing Pressure Vehicles Vehicles with low ground bearing pressure tyres or with rubber tracks may be employed for certain lightweight operations e.g. taking small quantities of material or a small team of operatives to remote sites. Additional access protection may not be needed if these operations can be carried out without leaving track marks, usually only possible in dry conditions. It would be the responsibility of the successful Principal Contractor(s) to determine the most appropriate route and method of access to each tower location, dependent on the local ground conditions, landowner consultations and the level of construction works required at each tower. No new watercourse crossings or upgrades to existing watercourse crossings are currently anticipated to be required to facilitate access for construction of the Proposed Development. In the event that the Principal Contractor(s) identify a requirement for any new or upgraded watercourse crossings, the design and capacity of the crossings would be agreed by the Principal Contractor(s) in consultation with the Scottish Environmental Protection Agency (SEPA) as part of the detailed design, and appropriate authorisations would be obtained as required.
Phase 2 –OHL Upgrade Works Re-conductoring Works The existing twin Zebra 400 mm2 Aluminium Conductor Steel Reinforced (ACSR) phase conductors would be replaced with Twin Totara type conductor bundle or alternative Triple (AL4) Upas equivalent type conductor bundle. As technology options are continuously advanced and improvements made in order to reduce any effects associated with conductor types, the specific product types may be further optimised as part of detailed design.
Re-conductoring is generally undertaken in sections of between 5 to 15 towers in length, with each section taking approximately one to two weeks to complete depending on the number of towers within the section. Re-conductoring teams usually consist of 20 to 25 suitably trained and qualified personnel. For each section to be re-conductored, the towers at either end would be set up for positioning of winching and tensioner equipment, conductor drums and reels. This machinery requires to be set up on an EPZ to protect the workers from potential electric shock. The EPZ would typically consist of metal trackway panels covering an area of approximately 12 m by 8 m. Some towers may require two EPZ areas to be set up, depending on location.
3-5 All towers within the pull section would be accessed to prepare the tower site and to prepare the conductors for pulling. This would involve setting up demarcation around the tower base and working areas using warning cones, ropes or temporary barriers. The tower peaks and arms would be accessed to remove existing fittings and dampers and to transfer the conductors into a running out block attached to the tower steelwork. The towers at either end of the pull would be set up with a winch at one end and a tensioner machine at the other. These machines would be positioned on the EPZ and anchored. The conductor drum with the new conductor would be set up at the tensioner end tower, while empty drum reels would be set up at the winch end to spool the conductor being replaced. The towers at both ends would be accessed and rigged to the equipment on the ground. Photograph 3.1 illustrates a typical EPZ with equipment set up for re-conductoring.
Photograph 3.1 Typical EPZ with equipment set up for re-conductoring
Once works are set up, the pulling out of the new conductors would be carried out. This is done by pulling in the old conductor which in turn is connected to the new conductor. As the old conductor is pulled through and reeled up from one end of the section, the new conductor is pulled through behind it. During the pull, operatives with radio communication would be positioned at key locations within the section to observe the operations and monitor progress. The operation would continue until the new conductor has been pulled through all towers in the section with the old conductor now spooled. The winch and tensioner machines would be used throughout this operation to control the sag until the new conductor is connected into the conductor fittings at either end of the section, along with a tail formed down each end tower in preparation for jointing the conductors. Re-Sagging of the existing Earthwire
The existing earthwire / OPGW (Keziah 237.6 mm2 AACSR / ACS (20.58 mm diameter)) would be re- sagged to maintain mandatory electrical distances (phase to earth) and lightning shielding angle requirements with the new conductors (complying with the latest British Standard BS EN 50341-2-9).
Re-sagging is generally undertaken in sections matching those used for re-conductoring as per paragraph 3.6.17. The teams required for re-sagging may be different from the re-conductoring team and comprise fewer personnel.
For each section to be re-sagged, the existing OPGW located on the top / peak of the towers would be transferred to roller blocks to release the current loads / tensions, in a similar way as described in paragraph 3.6.19.
3-6 Once all suspension towers within the re-sag section have been transferred to roller blocks, a new load / tension would be pulled or released at the towers at either end of the section. When the required load / tension values have been achieved, the OPGW would be clamped in place again to each tower in a similar way as described in the following paragraphs 3.6.33 and 3.6.34.
Replacement of Insulators and Fittings Insulators and fittings would be replaced along each pull section at the same time as the re- conductoring works are undertaken, in order to minimise the number of visits required to each tower location. The exact method of working would be determined by the successful Principal Contractor(s). Typically, once the conductor has been transferred to a running out block attached to the tower steelwork, the old insulator string would be disconnected from the tower crossarm and lowered to the ground. The new insulator string would be lifted up, and attached, to the crossarm. This work is typically carried out by a team of four operatives plus a chargehand and a plant operator using a transit type van and / or low ground bearing pressure vehicles, where necessary. A small winch may also be used to lift and lower the insulator strings. Pull lifts would likely be used to lift and support the conductors whilst the insulators are replaced.
For suspension towers11, the operatives would typically access the conductor beneath the tower crossarms by using lightweight aluminium hook ladders. The ladders may be hoisted up the tower manually or by using a small winch.
For tension towers12, a tower working platform would be required to enable the operatives to access the conductors and insulators. This would be lifted into place utilising the winches set up for conductor restringing, and securely attached beneath the appropriate tower crossarm and stabilised with temporary ground anchors. It is likely that one suspension insulator changing team would be able to change the insulators on two towers on one circuit (i.e. six suspension insulator sets) per day. Tension insulators would take longer to replace (approximately three insulator sets per day), due to the requirement to install a working platform.
11 Suspension towers are towers where the conductors are suspended from the towers by vertically hanging insulators and are generally used where the OHL follows a straight route. 12 Tension towers are towers where the insulators connect horizontally to the towers and can accommodate an angle / change of direction for the OHL route. 3-7 Photograph 3.2 shows a team of operatives replacing insulators sets on an existing OHL suspension tower.
Photograph 3.2 Replacing insulators on an existing OHL tower
Conductor Clipping In On completion of re-conductoring, insulator replacement and the sagging of conductor final tension, the conductors would be clamped into new suspension clamps at each suspension tower, commonly referred to as ‘clipping in’. Typically, teams of four operatives, with one van and one all-terrain vehicle (ATV), would carry out clipping in operations.
Scaffolds and Crossings In some instances, where there are no hazards in the spans beneath the conductor section, it may be acceptable to use safety slings as a precaution to restrain the conductors in the event of a failure on the primary equipment. However, where there are major road, rail or built-up area crossings under the section of the route being uprated, it is likely that a form of mechanical protection, such as scaffolding or other approved method, would need to be supplied and erected to provide protection to members of the public and property in case of equipment failure. Such areas would be identified by the successful Principal Contractor(s) and appropriate protection methods agreed with the relevant Local Authority. Photograph 3.3 shows an example of a temporary construction scaffold at a road crossing.
3-8 Photograph 3.3 Illustrative Image of Temporary Construction Scaffolds Steel Works and Foundation Works
Steel and foundation reinforcement works would be undertaken at existing tower locations along the OHL Route. The exact location of where such works are required would be determined by the successful Principal Contractor(s) following engineering studies and OHL condition assessments.
Steel Works Steel reinforcement works would comprise the replacement of damaged steelwork and the addition of new steel bars, where required, to strengthen tower arms13. New steelwork, plant and materials would be delivered to each tower location by a 4x4 Hiab wagon or similar, immediately prior to commencement of the works at that location. A team of 3-4 engineers would undertake the steel reinforcement works, which would take approximately two days per tower location. At each tower identified for reinforcement, the working area would be demarcated with warning cones, barriers or temporary fencing. The steel bars would be lifted and lowered in a controlled manner using a rope or winch, and new bars secured into place. On completion of the works, all scrap materials would be removed from the site and placed in skips at the main compound area for collection by a licensed waste contractor. Foundation Works
Foundation reinforcement works may be required where engineering studies indicate that the existing foundations are not strong enough to support the new conductors. The foundation works would comprise the following steps: · materials and plant would be delivered to the tower locations by 4x4 Hiab wagon, or similar; · the area to be excavated would be marked out by the site engineer or foreman and excavated using a tracked excavator. Topsoil and subsoil would be stockpiled in separate areas for final replacement when backfilling; · the excavation would be protected from collapse in accordance with the statutory regulations, and all excavations fenced off using edge safe protection barriers, or Heras panels if livestock are present in the field;
13 Initial engineering studies indicate that approximately 60% of towers may require strengthening across the OHL Route. The exact strengthening requirements would be determined by the successful Principal Contractor(s) at detailed design stage. 3-9 · any excess water from the excavation would be pumped out and discharged to suitable ground, with sediment control measures implemented if required in consultation with the project ECoW; · the excavation would be prepared for concrete pouring, and the existing concrete column removed using the excavator with a mounted hydraulic breaker and / or hand breaker; · following completion of all foundation preparation works, ready-mixed concrete would be ordered for delivery to the site. The concrete would be poured into the excavation until the pad and column is complete, where possible in one pour; · following completion of concrete works and after allowing sufficient curing time, all formwork and excavation shoring equipment would be removed from the excavation, and the excavation backfilled with suitable soil free of any large stones or boulders and covered with topsoil to the original ground surface level; and · on completion of the works, all materials and equipment would be removed from the site.
Tower Extensions To ensure adequate ground clearance is maintained following the replacement of conductors and insulators, some of the existing steel lattice towers may require height extensions. Initial engineering studies have identified a maximum of 73 towers that would require extensions of up to 10% of their existing height. These locations are shown in Figure 3.2 – Tower Extension Locations and the proposed tower height increases are detailed in Table 3-1 below.
Table 3-1 Towers to be extended and approximate increase in height
Tower Number Tower Type Existing Tower Height (m) Approximate Extension Required (m) 40 L2 D E8 39 4m 48 L2 D STD 41 4m 51 L2 D E8 39 3m 56 L2 D E24 48 3m 59 L2 D E16 46 4m 62 L2 D E8 39 4m 70 L2 D STD 41 4m 80 L2 D STD 41 2m 81 L2 D E16 46 3m 82 L2 D E20 47 3m 97 L8 D E8(2) E12(2) 50 3m 98 L8 D30 M12 40 3m 114 L8 D10 M12 40 2.5 132 L8 D E4 47 3m 133 L8 D M8 43 3m 136 L8 D E12 50 2.5m 148 L8 D E16 51 4m 149 L8 D10 M12 40 2m 150 L8 D E20 52 3m 151 L8 D E24 53 3m 155 L8 D E24 53 3m 158 L8 D M4 45 4m 172 L8 D E20 52 3m
3-10 Tower Number Tower Type Existing Tower Height (m) Approximate Extension Required (m) 177 L8 D E28 54 4m 183 L8 D E8 48 4m 185 L8 D E16 51 3m 212 L8 D E12 50 2m 241 L8 D E4 47 3m 243 L8 D M8 43 3m 244 L8 D M8 43 3m 246 L8 D E8 48 4m 248 L8 D STD 46 3m 249 L8 D M8 43 3m 255 L8 D E8 48 2m 260 L8 D E8 48 3m 269 L8 D E8 48 3m 281 L8 D M8 43 2m L8 D E8 E12 E12 50 286 3m E8 288 L8 D M4 45 2m 291 L8 D E24 53 3m 293 L8 D M4x2 M8x2 45 2m 294 L8 D60 M12 40 2m 295 L8 D E8 48 3m 297 L8 D E16 51 2m 301 L8 D STD 46 3m 303 L8 D M8 43 2m 307 L8 D E24 53 3m 313 L8 D STD 46 3m 325 L8 D STD 46 2m 336 L8 D E12x2 E8x2 50 4m 365 L8 D10 M24 36 2m 369 L8 D E4 47 3m 399 L8 D E4 47 2.5m 404 L8 D10 STD 43 2.5m 423 L8 D10 M24 36 2m 425 L8 D M16 41 2m 426 L8 D30 M24 36 4m 429 L8 D30 M12 40 2m 431 L8 D M8 43 3m 434 L8 D STD 46 4m 441 L8 D M12 42 2m 443 L8 D30 STD 43 2m 447 L8 D E12 50 4m
3-11 Tower Number Tower Type Existing Tower Height (m) Approximate Extension Required (m) 449 L8 D10 M24 36 3m 491 L8 D M4 45 4m 494 L8 D10 M24 36 3m 495 L8 D M4 45 2m 501 L8 D10 STD 43 2m 502 L8 D E4 47 3m 509 L8 D M8 43 4m 511 L8 D STD 46 3m 524 L8 D M8 43 3m 536 L8 D E16 51 3m
Temporary Diversions To facilitate the construction of a tower extension, either an outage on both circuits of the overhead line or a temporary diversion would be required. The temporary diversion moves one circuit a safe distance away from the tower to be worked on; this circuit is then re-energised, and the other circuit is then taken under outage to allow the works on the tower to take place. This maintains the network with at least one circuit in operation and is the planned approach for the Proposed Development.
The temporary diversion would use either conventional towers on a temporary basis or temporary masts. This would allow the conductors of one circuit to be moved away from the existing tower. The location, ground conditions and time of year would dictate what method is used and generally one side would be used in preference to the other depending on the local conditions and access required to position plant and equipment. Photograph 3.4 shows an example of a typical temporary mast structure.
Photograph 3.4 Illustrative Image of Temporary Mast Structure
3-12 The use of conventional towers on a temporary basis would require the same construction methods used for a permanent tower and would retain the comparatively small footprint of the tower base. The temporary mast is a guyed structure and requires minimal foundation works, it is quicker and cheaper to erect but does take up a larger working area to accommodate the back guys. Temporary masts will be the preferred method but can be limited by space and not preferred for longer-term use as require regular inspection or for winter operation. The works would take approximately five days to establish the diversion and move the conductors under single circuit outage. The diversion would then be re-energised and remain in place for the time required to carry out any associated works (anticipated to be a maximum of 6 months). Once the work is completed a further five-day outage would be required to transfer the conductors back onto the existing line and then recover the temporary masts. The location and route of the required temporary diversions would be confirmed by the Principal Contractor(s) at the detailed design stage, depending on factors such as ground conditions and constraints such as existing buildings, infrastructure, trees and environmental constraints. The majority of temporary diversions would extend between the towers either side of the tower to be extended (i.e. over two spans) and would be located within 100 m of the existing OHL route.
The exact height and type of temporary mast structure to be used would also be confirmed by the Principal Contractor(s) at the detailed design stage, however it is anticipated that temporary masts would be similar in height to the existing towers (may be up to ±20% higher than the existing towers).
Installation of Tower Extensions Tower extensions are carried out by adding an extra body section below the bottom crossarm level. This effectively lifts the top part of the tower by the appropriate distance. Typically, the panels add between 2 – 4 m onto the height of the existing tower. The tower extensions would require the use of a crane to lift the top part of the tower, allowing a body extension to be installed, then re-attach the top part of the tower onto this new extension.
Access would be required to adjacent towers to allow conductors to be moved to the temporary diversion and lowered from the tower being worked on. Therefore, access will be required to these adjacent towers and work carried out in a similar manner as explained in paragraph 3.6.4 – 3.6.15.
In the absence of a suitable existing access road, a temporary stone access track would be required to facilitate crane access to the tower to be extended. A laydown area would be developed at the base of the tower location to create a crane pad and an area to prepare the body extension panels. It would be the responsibility of the Principal Contractor(s) to determine the most appropriate route and method of access to each tower location. The whole operation would typically take up to 6 months to set up the temporary masts and prepare the body extension, divert one circuit under outage, install the tower extension with the other circuit on outage, transfer back the first circuit from the diversion and remove the temporary masts. The works may, however, take longer depending on the demands on the overall transmission network and the availability of moving outages between the two circuits. Mobile Security Mobile security would be required to patrol at all non-working times where materials, plant and equipment are positioned outside the main compound areas and sub yards to deter theft and vandalism. Static or mobile security may also need to be considered at the main stores' site and at any satellite storage sites. Security staff would typically be hired as required from an approved specialist subcontractor.
3-13 Phase 3 - Commissioning The OHL and support towers would then be subject to an inspection process to check and repair minor defects. This allows the successful Principal Contractor(s) and the Applicant to check that the works have been built to specification and are fit to energise. The Proposed Development would also go through a commissioning procedure for the switchgear, communications and protection controls through the substations at Kintore, Fetteresso, Alyth and Kincardine. The circuits would then be energised from the substations with the capacity to carry 400 kV.
Phase 4 – Reinstatement All construction sites shall be reinstated. Reinstatement shall form part of the contract obligations for the successful Principal Contractor(s) and would include the removal of all temporary tower access routes, all work sites around the tower locations and the reinstatement of all construction compounds and decommissioned structures. Reinstatement of Tower Access Routes
Reinstatement of excavated temporary stone tracks would involve the replacement of subsoil and topsoil, and grading and installation of drainage, as required, with turves replaced vegetation side up. Where there are insufficient turves the ground would be allowed to vegetate naturally, although some seeding may be required to stabilise sites and prevent erosion, or where landowner requirements dictate otherwise. Temporary tracks placed on top of the existing ground level would not require any reinstatement measures.
Reinstatement of Tower Sites Where required (e.g. where foundation strengthening has occurred), the soil would be stored within the working area at each tower during the works. Subsoils and topsoil removed to enable the reinforcement of the foundations would be temporarily stockpiled in separate bunds within the working area, with stripped turves stored on top of the bunds. Reinstatement would involve the replacement of subsoil and topsoil, with turves replaced vegetation side up. Where there are insufficient turves the ground would be allowed to re-vegetate naturally. Reinstatement of Construction Compounds Construction compound sites would be reinstated at the end of construction with all buildings and materials removed and soils appropriately reinstated.
3.7 Construction Employment and Hours of Work The Applicant considers it important to act as a responsible developer with regards to the communities which host the construction works. The delivery of a major programme of capital investment provides the opportunity to maximise the support of local communities. Employment of construction staff would be the responsibility of the successful Principal Contractor(s); however, the Applicant encourages the successful Principal Contractor(s) to make use of suitable labour and resources from areas local to the location of the Proposed Development. It is envisaged that there will be a number of separate teams working at the same time at different locations within the vicinity of the Proposed Development. The resource levels will be dependent on the final construction sequence and will be determined by the successful Principal Contractor(s). Construction activities would in general be undertaken during daytime periods only. For weekdays, this would involve work between approximately 07:00 to 19:00 in the summer and 07:30 to 17:00 (or as daylight allows) in the winter. At weekends, the working hours would be approximately 07:00 to 17:00 in the summer and 07:30 to 17:00 (or as daylight allows) in the winter.
3-14 Any variation in these working hours would be agreed in advance with the appropriate local authorities.
3.8 Construction Traffic Construction of the Proposed Development will give rise to regular numbers of staff transport movements, with small work crews travelling to work site areas. It is anticipated that the successful Principal Contractor(s) will identify a minimum of three main compound areas, with a safe area for parking away from the public highway. Additional temporary compound areas will be identified as necessary.
Vehicle movements will be required to construct temporary or upgraded access roads; deliver the foundation and tower components and conductor materials to site, and deliver and collect materials and construction plant from the main site compound and to individual tower locations.
The successful Principal Contractor(s) would determine where access is required, and for which items of plant, and prepare Construction Traffic Management Plans (CTMP) in consultation with the Applicant and the local authorities. The CTMP would describe all mitigation and signage measures that are proposed on the public road accesses based on access maps and subsequent site assessments. Temporary traffic lights may be required at some locations (e.g. for delivery of scaffold materials). For minor tracks and other crossings, the installation of appropriate warning signs and provision of staff with stop / go boards to control any passing traffic may be adequate. Table 3-2 provides an indicative summary of the total anticipated traffic movements associated with the construction of the Proposed Development, broken down by Phases.
Table 3-2 Anticipated Construction Traffic Movements
Project Phase Peak Light Vehicles / Day Peak Heavy Vehicles / Day
OHL Upgrade Works 6 2
OHL Commissioning 4 2
3.9 Operation and Management of the Transmission Connection In general, an OHL requires very little maintenance. Regular inspections are undertaken to identify any unacceptable deterioration of components so that they can be replaced. From time to time, inclement weather, storms or lightning can cause damage to either the insulators or the conductors. If conductors are damaged, short sections may have to be replaced. Insulators and conductors are normally replaced after about 40 years, and towers painted every 15 to 20 years.
3-15 4 EIA CONSULTATION AND SCOPE
4.1 Introduction This chapter describes the pre-application consultation and EIA scoping process that was undertaken to determine the scope of the EIA Report, and sets out the consultation that has been undertaken to date. This chapter also provides a brief description of the potentially significant effects associated with the Proposed Development which are to be addressed in detail in this EIA Report. The issues which have been scoped-out of this EIA Report are also detailed within this Chapter.
4.2 Pre-Application Consultation Best practice in EIA encourages consultation and engagement with stakeholders early in the process, with advice and input from key consultees being sought at the early design stages of a project, to inform decisions about the Proposed Development. Stakeholder consultation has been ongoing since the early stages of the project and has continued throughout the EIA process. Further information on consultation undertaken for each environmental topic assessment is available in each topic’s respective chapter of this EIA Report. Following advertisement in local newspapers, a press release, social media notices, e-mail to community councils and ward councillors and distribution of a consultation booklet to 1,172 properties along the OHL Route, three public consultation events were undertaken between 1st and 3rd September 2020. In compliance with current Scottish Government guidelines on public consultation during this period14, the event was held online only. A dedicated public consultation section on SSE’s webpage for the project was made available, which provided information on the background, description, need and potential impacts of the Proposed Development, amongst other information. Representatives from the project team were also available to assist with specific queries. Members of the public were given until the 9th October 2020 to provide feedback. Responses to the public consultation were in the Report on Consultation which accompanies this application.
4.3 Scoping Prior to a request for a Scoping Opinion being submitted to the Energy Consents Unit (ECU), a Scoping Briefing Note (SBN) was prepared and submitted to a number of key statutory stakeholders to initiate initial discussions on the scope of this EIA Report. A summary of the feedback obtained, via email in response to the SBN, is summarised in Table 4-1 below:
14 Coronavirus (COVID-19): planning guidance on pre-application consultations for public events (Scottish Government, 2020). 4-1 Table 4-1 Summary of Consultation Responses to SBN
Statutory Consultee Response Summary Perth & Kinross Council Generally comfortable with the approach presented in the SBN. Angus Council Generally comfortable with the approach presented in the SBN. Points of clarification on access and noise impacts have been sought from Council Services and subsequently addressed in the Scoping Report. Aberdeenshire Council Generally comfortable with the approach presented in the SBN. A suggestion for further information was provided in relation to the assessments for Ecology and Noise which have been addressed in the Scoping Report. Scottish Environmental Generally comfortable with the approach presented in the SBN. Protection Agency (SEPA) Scottish Natural Heritage Generally comfortable with the approach presented in the SBN. (SNH) Historic Environment Generally comfortable with the approach presented in the SBN. Advice Scotland (HES) provided in relation to direct impacts to Scheduled Monuments is noted and addressed in the Scoping Report, which will also be included within the Construction Environmental Management Plan (CEMP).
The feedback received informed the content and the structure of the Scoping Report. Stakeholder consultation has been ongoing since initial feedback obtained in response to the SBN. An EIA Scoping Report was issued to ECU on 22nd May 2020 (see Appendix 4.1: EIA Scoping Report). A Scoping Opinion was provided by ECU on 14th August 2020, and is included in Appendix 4.2: EIA Scoping Opinion. Following the EIA Scoping consultation, a change in the design to include tower height extension works (described in Section 3.4 – Construction Practices and Phasing) necessitated re-consultation with the ECU and key consultees. Further consultation was subsequently sent to the same key consultees upon additional design work identifying a need to increase the number of towers requiring extension. In addition to describing the tower extension works, the consultation informed that a review of the additional works against the scoping report had been undertaken and that no change to the proposed assessment methodology was required. Details of this are provided in Appendix 4.3: Tower Extension Consultation along with responses to this re- consultation.
The responses, contained within the Scoping Opinion and re-consultation, have been considered in detail during the EIA process. A summary of the key points raised in the Scoping Opinion and how they have been addressed is provided in Appendix 4.4: Gatecheck Report.
4.4 Gatecheck In accordance with the requirements of the gate checking procedures for Applications under Section 37 of The Electricity Act 1989, a Gatecheck Report was issued to the ECU on the 13th November 2020 and published by the ECU for key stakeholders on 23rd November 2020.
The purpose of the Gatecheck Report is to outline consultations with statutory and non-statutory consultees, engagement with the local community and how matters raised during the scoping process have been dealt with in the EIA Report. Key stakeholders are invited to comment on the Gatecheck Report to ensure they are satisfied with the approach taken within the EIA Report prior to submission of the application. A copy of the Gatecheck Report is provided in Appendix 4.4: Gatecheck Report. Responses to the Gatecheck report confirmed the acceptability of the approach taken within the EIA Report.
4-2 4.5 Potentially Significant Issues In response to the consultation received during the scoping process and the ongoing stakeholder consultation, issues relating to the following key environmental areas associated with the Proposed Development have been identified as the most relevant to the Proposed Development and are therefore addressed in the EIA and discussed in the EIA Report: · Chapter 6: Hydrology, Hydrogeology and Soils – construction impacts considering surface watercourses, groundwater and Private Water Supplies (PWS), water resource availability, mobilisation of contaminated soil / bedrock, impact upon fisheries, flooding, soil erosion, loss of peat soils and impacts upon GWDTE; · Chapter 7: Biodiversity – construction impacts considering impacts upon ecologically designated sites, impacts upon legally protected and notable species and impacts upon habitats; · Chapter 8: Cultural Heritage - construction impacts upon archaeological and Cultural Heritage features; · Chapter 9: Noise and Vibration – operational noise impacts upon receptors in proximity to the OHL; and · Chapter 10: Electromagnetic Fields – operation impacts with an assessment of the change in EMF strengths.
4.6 Scoped-out Issues The following topics are considered to be not significant and were scoped out from further consideration within the EIA process. Where not all aspects of a topic were scoped out, a chapter is included in the EIA Report with an appropriate explanation provided. Individual elements scoped out of any particular topic are detailed in the relevant technical chapter. For detail regarding the justification for scoping out the following topics see Appendix 4.1: EIA Scoping Report and Appendix 4.3: Tower Extension Consultation. · Landscape and Visual; · Land Use (forestry specifically is scoped in); · Recreation and Tourism; · Air Quality and Climate; · Material Assets and Waste; · Major Accidents and Disasters; · Population and Human Health; · Traffic and Transport; and · Radio and TV Interference.
4-3 5 METHODOLOGY
5.1 Introduction This chapter sets out the approach that has been taken to complete the EIA of the Proposed Development, including reference to legal requirements, best practice and assessment parameters. This EIA Report contains the information specified in the EIA Regulations. The approach to the assessment has been informed by current best practice guidance, including the following: · Planning Circular 1 2017: Environmental Impact Assessment Regulations 2017; · Historic Environment Scotland and Scottish Natural Heritage’s ‘Environmental Impact Assessment Handbook’ 2018 version15; and · IEMA’s guidance documents on EIA practice including Delivering Proportionate EIA16; Environmental Impact Assessment Guide to Shaping Quality Development17 and Environmental Impact Assessment Guide to Delivering Quality Development18.
The overarching technical assessment methodology is summarised in the flow diagram below, Chart 5.1. An overview of the guidance and methodology adopted for each technical study is provided within the respective technical chapters of this EIA Report (Chapters 6 - 11).
5.2 Identification of Baseline To identify the scale of likely significant effects as a result of the Proposed Development, it is necessary to establish the existing baseline environmental conditions and their sensitives. The baseline scenario was established through the following methods, where relevant: · Site visits and surveys; · Desk-based studies; · Review of existing information; · Modelling; · Review of relevant national and local planning policies; · Consultation with the relevant statutory consultees; and · Identification of Sensitive Receptors. The general EIA assessment methodology is summarised in the flow diagram below, Chart 5.1.
15 Historic Environment Scotland and SNH (2018). Environmental Impact Assessment Handbook. Edinburgh: Historic Environment Scotland and SNH 16 IEMA (2017). Delivering Proportionate EIA. Lincoln: IEMA 17 IEMA (2015). Environmental Impact Assessment Guide to Shaping Quality Development. Lincoln: IEMA 18 IEMA (2016). Environmental Impact Assessment Guide to Delivering Quality Development. Lincoln: IEMA 5-1 Chart 5.1: Summary of Methodology for Environmental Effects
Define Scope of Assessment: Study Area Describe the characteristics of the Range of people & places that may be proposal affected Refer to Chapter 3
Establish Environmental Baseline Refer to Technical Chapters
Identify interaction between Identify Receptors proposal and receptors Refer to Technical Chapters
Identify the changes and likely effects and, for each effect:
Judge Judge value Judge size/ Judge Judge susceptibility of attached to scale of duration of reversibility receptor to receptor change change of change specific change
Combine to judge sensitivity of Combine to judge magnitude of effect: receptor: High High Medium Medium Low Low Negligible Negligible Refer to Table 5-1 Refer to Table 5-1
Propose measures to Combine to judge determine mitigate significant adverse significance of effect effects (moderate or above) Refer to Technical Chapters
Determine significance of residual effects
Final Report of likely significant effect Refer to Technical Chapters
5.3 Assessment of Likely Significant Environmental Effects For the purposes of this EIA Report the terms used in the assessment are generally defined as follows: · Impact – is specific and defined as the action being taken, for example, cutting down trees; · Effect – is defined as the change resulting from that action, for example, loss of habitat;
5-2 · Temporary - where the effect occurs for a limited period of time and the change at a defined receptor can be reversed; · Permanent - where the effect represents a long-lasting change at a defined receptor which is not reversable; · Direct - where the effect is a direct result (or primary effect) of the Proposed Development; · Indirect - a knock-on (or secondary) effect which occurs within or between environmental components, may include effects on the environment which are not a direct result of the Proposed Development, often occurring away from the proposals or as a result of a complex biological or chemical pathway; · Secondary – an induced effect arising from the actions or presence of a project, such as changes to the pattern of future land use or improvements to local road networks; · Cumulative - these effects may arise when more than one development of a similar scale and nature combine to create a potentially greater impact than would result from the Proposed Development alone (see also Section 5.5 below); · Beneficial – an effect beneficial to one or more environmental receptors; and · Adverse – a detrimental, or negative, effect on one or more environmental receptors.
Where a more appropriate definition of the above terms is applicable to a technical discipline this is clearly outlined with the technical Chapters 6-11. The result of the assessment is the determination of whether the likely effect of the Proposed Development on the receptor in the study area would be significant or not significant.
Several criteria have been used to determine whether or not the likely environmental effects of the Proposed Development will be deemed 'significant'. The effects have been assessed quantitatively where possible. Generally, the significance of effects has been assessed using one or more of the following criteria: · International, national and local standards; · Sensitivity of the receiving environment; · Extent and magnitude of the effect; and · Reversibility and duration of the effect.
The assessment of significance has considered the magnitude of change (from the baseline conditions), the sensitivity of the affected environment / receptors and (in terms of determining residual effects) the extent to which mitigation and enhancement will reduce or reverse adverse effects. In addition, further influences such as those listed below have been factored into the assessment using professional judgement: · Likelihood of occurrence; · Geographical extent; · The value of the affected resource; · Adherence of the proposals to legislation and planning policy; and · Reversibility and duration of the effect. The magnitude (scale) of change for each effect has been identified and predicted as a deviation from the established baseline conditions, for the construction and operational phases of the Proposed Development. The scale used high, medium, low, and negligible criteria, as outlined in Table 5-1 below and defined within Chapters 6-10. As the Proposed Development concerns upgrading and refurbishment of existing structures, decommissioning is not considered applicable and is scoped out of the EIA.
5-3 The sensitivity of the receptor / receiving environment to change has been determined using professional judgement, consideration of existing designations (e.g. Sites of Special Scientific Interest (SSSIs)) and quantifiable data, where possible. The scale used high, medium, low, and negligible criteria, as outlined in Table 5-1 below and defined within Chapters 6-10.
Each effect has been assessed taking account of the predicted magnitude of change and the sensitivity of the receptor as shown in Table 5-1 below to determine an overall significance.
Table 5-1 Matrix for Determining the Significance of Effects
Sensitivity of Receptor/Receiving Environment to Change/Effect
High Medium Low Negligible
High Major Major Moderate Negligible
Medium Major Moderate Minor Negligible
Low Moderate Minor Minor Negligible
Magnitude of Change/Effect Negligible Negligible Negligible Negligible Negligible
Major and moderate effects are considered to be significant in the context of the EIA Regulations. Minor and negligible effects are not considered significant. Specific criteria have been adopted for certain technical assessments in accordance with widely recognised EIA guidelines published by professional bodies. Where applicable, these are provided in the respective technical chapters. Where no published standards exist, the assessments presented in the technical chapters describe the professional judgements (assumptions and value systems) that underpin the attribution of significance. For certain technical topics, such as ecology, widely recognised published significance criteria and associated terminology have been applied and these are presented in the technical chapters and associated appendices where relevant.
The characteristics of an effect will vary depending on the duration of the activity causing the effect, the sensitivity of the receptor and the resultant change. It is, therefore, necessary to assess whether the effect is temporary or permanent; beneficial and adverse, and indirect or direct. Effects that are temporary are usually reversible and generally confined to the construction period.
5.4 Identification of Mitigation Measures Following the initial assessment, mitigation measures have been recommended to prevent, reduce or remedy any potentially significant adverse environmental effects identified. Such measures will be implemented during detailed design, construction and / or operation of the Proposed Development. Each technical chapter details the measures recommended to mitigate any identified significant effects, and a summary of the recommended mitigation measures are provided in Chapter 12: Schedule of Environmental Mitigation. Following the implementation of mitigation measures, an assessment of the significance of any residual effects has been undertaken. The findings are presented in each technical chapter of this EIA Report.
5.5 Cumulative Effects There are two aspects to Cumulative Effects, defined as follows: · In-combination effects: The combined effect of the Proposed Development together with other reasonably foreseeable developments (taking into consideration effects at the site preparation and earthworks, construction and operational phases); and
5-4 · Effects Interactions: The combined or synergistic effects caused by the combination of a number of effects on a particular receptor (taking into consideration effects at the site preparation and earthworks, construction and operational phases), which may collectively cause a more significant effect than individually. A theoretical example is the culmination of disturbance from dust, noise, vibration, artificial light, human presence and visual intrusion on sensitive fauna (e.g. certain bat species) adjacent to a construction site.
A search for other developments has been undertaken on 23rd July 2020. This considered developments recorded as requiring an Environmental Assessment within 5 km of the OHL which have been submitted or approved within the last 5 years. The findings are set out in Table 5-2 below and the location of each development is shown, indicatively, in Figure 5.1: Cumulative Developments. Each local authority was consulted to comment on the list of other developments identified within their area and where applicable their responses have been included.
Table 5-2 Other developments considered in the cumulative assessment
Application Planning application reference and Location Status reference name Description
North East 400 kV ECU00000677 Commences north Consented Overhead Line North East 400 kV Overhead Line from northern most Reinforcement Reinforcement Works point of the Proposed Works Development Kintore Substation APP/2020/1437 Land To The West Of Consented Extension National for Electricity Substation Comprising Kintore Electricity Platform Area, Control Building, Associated Substation Leylodge Plant and Infrastructure, Ancillary Facilities, Kintore Aberdeenshire Landscape Works and Road Alterations and AB51 0X Improvement Works Kintore OHL ECU00002100 OHL connecting into Awaiting diversions Overhead line diversion works to connect into Kintore substation Decision Kintore substation Craigneil Wind Farm APP/2018/0993 Craigneil Windfarm Awaiting Erection of 11 Wind Turbines, Formation of Land To The North And Decision Access Tracks, Hardstandings, Substation, North East Of Hillside Control Building, Met Mast, Borrow Pit, Rickarton Stonehaven Associated Infrastructure and Temporary Construction Compound Alyth Substation 19/01747/FLN Land 450 Metres North Approved Installation of an electricity substation and West Of Haughend ancillary buildings, formation of a vehicular Farm Meigle access and track, hardstanding areas, landscaping and associated works Alyth OHL diversion ECU00001952 OHL connecting to Consented Overhead line diversion works to connect into Alyth substation proposed Alyth 275/400 kV substation Marlee Quarry 20/00909/SCOP Marlee Quarry Essendy Awaiting Extension Extension to quarry decision Norwood Farm 19/00021/FLL Norwood Farm Approved Poultry Rearing Erection of a poultry rearing shed, 2 feed silos, Meikleour Perth PH2 Shed extension to hardstanding area and associated 6EN works Cross Tay Link Road 19/01837/FLM A9 Over the River Tay Consented Formation of the Cross Tay Link Road and to the A93 And A94 associated works
5-5 Application Planning application reference and Location Status reference name Description North of Scone Cross Tay Link Road Luncarty South 17/00847/IPM Land 250 Metres South Approved Residential and Mixed use development comprising residential East Of Wilmarean Luncarty Employment development, employment land, infrastructure Development including roads, footpaths, landscaping, drainage, open space and associated works Bertha Park 15/01112/IPM Land At Bertha Park Approved Residential Residential development with community Perth Development facilities, employment land, open space, landscaping and associated infrastructure (in principle) Bertha Park 15/01109/FLM Land At Bertha Park Approved Residential Erection of residential units, commercial units Perth Development (Classes 1,2,3 and 10), formation of allotments/open space, landscaping and associated infrastructure works Scone North 16/02127/IPM Scone North Scone Approved Residential Residential development with open space, Development landscaping, drainage and associated infrastructure (in principle) Almond Valley 19/01433/AMM Land Adjacent To Awaiting Residential Erection of 284 dwellinghouses, 21 detached Huntingtowerfield And decision Development garages, 56 flats, 3 retail units, a refuse/bike Ruthvenfield Huntingtowerfield store and a sports changing pavillion, formation of boundary treatments, retaining walls, leisure facilities, SUDS ponds, parking areas, landscaping and associated works (approval of matters specified in conditions of 15/01157/IPM) (Phase 1 and 1A) (allocated site MU73) Almond Valley in 15/01157/IPM Land Adjacent To Approved on Huntingtowerfield And Principle Residential development with school and appeal Ruthvenfield community facilities, open space, landscaping Huntingtowerfield and associated infrastructure (in principle) Former Murray 18/00094/IPM Former Murray Royal Awaiting Royal Hospital Residential development (in principle) Hospital Muirhall Road decision Residential Perth Development Perth West 20/00667/IPM Perth West (mu70) Old Awaiting Gallows Road Perth Residential Mixed use development comprising decision Development In residential, business (class 4), general industry Principle (class 5), storage […] (in principle) Aviva Wind Turbine 18/01656/FLL Erection of a wind turbine and Aviva Headquarters Refused ancillary equipment Pitheavlis Perth, PH2 0NH East Coast 400 kV No current application. SHE Transmission-SPT Project Incremental licence boundary at development Reinforcement Uprating of existing 275 kV overhead line Blairingone to (pre-s37 (ECUP) equipment and construction of associated Kincardine application) infrastructure to enable the line within SPT’s Scottish Power licence area to operate at 400 kV Transmission (SPT)
5-6 The individual technical chapters present the findings of the assessment of cumulative effects of the Proposed Development with other schemes. A summary of these effects and an assessment of cumulative effect interactions arising from the Proposed Development on certain sensitive receptors are described in Chapter 11: Cumulative Effects.
5.6 Assumptions and Limitations The key assumptions and limitations that have been identified in undertaking the EIA Report are set out below: · Baseline conditions have been established from a variety of sources, including historical data, but due to the dynamic nature of certain aspects of the environment, conditions will change during the construction and operation of the Proposed Development; · Information received by third parties is complete and up to date; and · The design, construction and completed stages of the Proposed Development will satisfy minimum environmental standards, consistent with contemporary legislation, practice and knowledge. Assumptions and limitations specific to certain topics are identified in the appropriate Chapters 6-10.
5-7 6 HYDROLOGY, HYDROGEOLOGY AND SOILS
6.1 Introduction This chapter assesses the potential effects on hydrology, hydrogeology and soils resulting from the Proposed Development. This chapter is accompanied by the following figure: · Figure 6.1: Hydrology, Hydrogeology and Soils Baseline Conditions
6.2 Assessment Methodology and Significance Criteria
Scope of the Assessment An EIA Scoping Report was submitted to the ECU in May 2020, which outlined the scope of this EIA based on the available baseline data at the time. This chapter focuses on the effects of the construction phase of the Proposed Development upon sensitive hydrological, hydrogeological features and takes a precautionary approach assessing sensitive receptors collectively due to the large extent of the Proposed Development. During the construction phase of the Proposed Development, there is the potential for the following short-term impacts on the hydrology, hydrogeology and soils environment in the absence of mitigation measures. · Pollution of surface watercourses, groundwater and water supplies; · Impact on water resource availability; · Impact of pollution on fisheries; · Short term increase in flood risk; · Soil erosion, compaction and excavation; · Loss of peat soils; and · Impacts upon groundwater dependent terrestrial ecosystems (GWDTE). There are no operational effects anticipated from the Proposed Development, therefore these have been scoped out from the assessment.
Extent of the Study Area The extent of the study area for the assessment encompasses sensitive receptors within the influence of the Proposed Development, up to and including 1 km from the OHL Route. This has been considered as 2 km for private water supplies (PWS). This radius is considered to be conservative for the assessment of potential adverse effects resulting from the Proposed Development.
Consultation Undertaken to Date Table 6-1 provides a summary of the consultation activities undertaken in support of the preparation of this chapter.
Table 6-6-1: Consultation responses of relevance to Hydrology, Hydrogeology and Soils
Organisation Type of Response How response has been Consultation considered Energy Consents EIA Scoping Scottish Water provides information on The DWPA and abstraction have Unit Report; June whether there are any drinking water been accounted for in this 2020 protected areas (DWPA) or Scottish Water assessment. assets on which the development could have any significant effect. Scottish Ministers request that the Applicant contacts Scottish
6-1 Organisation Type of Response How response has been Consultation considered Water and makes further enquires and includes details in the EIA report of any relevant mitigation measures provided and to enquire about a Pre-Development Enquiry Form before any application is submitted. Energy Consents EIA Scoping Scottish Ministers request that the Applicant Response noted. Potential Unit Report; June investigate PWS within close proximity to the effects on PWS during 2020 Proposed Development, which may be construction are considered impacted by the development. The EIA report within this assessment. should include details of these supplies Consultation with the Local identified by this investigation, the Applicant Authorities has been undertaken should provide an assessment of the potential to identify the location of PWS impact, risks, and any mitigation which would and these have been included be provided. within the assessment. Several of these PWS are located within 250 m of the indicative construction access routes and therefore mitigation which requires the adoption of the Private Water Supplies General Environmental Management Plan (GEMP) (GE9) is proposed to ensure the integrity of these PWS. Mitigation measures would be monitored by an Environmental Clerk of Works (ECoW) throughout construction. Energy Consents EIA Scoping Scottish Ministers consider that where there is A Peat Landslide Hazard Risk Unit Report; June a demonstrable requirement for peat landslide Assessment has been scoped 2020 hazard risk assessment, the assessment out of the EIA due to the limited should be clear understanding of whether the anticipated effects associated risks are acceptable and capable of being with the Proposed controlled by mitigation measures. The Peat Development. A desk-based Landslide Hazard and Risk Assessments: Best review has been undertaken Practice Guide for Proposed Electricity considering locations where Generation Developments (Second Edition), proposed construction activities published at would be most likely to cause http://www.gov.scot/Publications/2017/04/8 disturbance to any peat present. 868, should be followed in the preparation of With appropriate design and site the EIA report, which should contain such environmental management, assessment and details of mitigation likely activities in this area would measures. not be anticipated to cause a significant effect. At the pre- construction stage, further data will be collected at key locations throughout the Proposed Development and this situation will be refined with any appropriate mitigation measures determined if required. Scottish Water EIA Scoping The proposed activity is within a drinking The DWPA and abstraction have Report; June water catchment where a Scottish Water been accounted for in this 2020 abstraction is located. Scottish Water assessment. abstractions are designated Drinking Water Protected Areas (DWPA) under Article 7 of the Water Framework Directive. The River Tay supplies Perth Gowans Terrace Water Treatment Works (WTW) and it is essential that water quality and water quantity in the area are protected.
6-2 Organisation Type of Response How response has been Consultation considered
Scottish Water Data request No reply received. Scottish Water confirmed, via email; through their scoping response, June 2020 for that the Proposed Development details of is within a drinking water whether or catchment where a Scottish not there are Water abstraction is located public water (associated with Gowans supply source Terrace Water Treatment Works locations (WTW)). It is noted that this across the abstraction must be protected in area within terms of water quality and water the 2km quantity, and this has been buffer and if considered as part of this so, an assessment. No response was indication of received regarding the their location. consultation request for further Request Scottish Water registered assets chased located within a 2 km distance August 2020. of the OHL Route. Further consultation is required at the detailed design stage, should any Scottish Water assets be identified which require protection. Scottish Water EIA Scoping Asset Impact Assessment Response noted. Scottish Water Report; June According to our records, the development assets have been accounted for 2020 proposals impact on existing Scottish Water in this assessment. No assets assets. The applicant must identify any have been identified within 250 potential conflicts with Scottish Water assets m of the indicative construction and contact our HAUC Diversions Team via access routes or any of the 73 our Customer Portal to apply for a diversion. towers requiring extension. The applicant should be aware that any conflict with assets identified may be subject to restrictions on proximity of construction. Please note the disclaimer at the end of this response. Scottish Water EIA Scoping Surface Water Response noted. The Proposed Report; June For reasons of sustainability and to protect our Development will not be 2020 customers from potential future sewer connecting into the Scottish flooding, Scottish Water will not accept any Water combined sewer system. surface water connections into our combined sewer system. There may be limited exceptional circumstances where we would allow such a connection for brownfield sites only, however this will require significant justification from the customer taking account of various factors including legal, physical, and technical challenges. To avoid costs and delays where a surface water discharge to our combined sewer system is anticipated, the developer should contact Scottish Water at the earliest opportunity with strong evidence to support the intended drainage plan prior to making a connection request. We will robustly assess this evidence and provide a decision that reflects the best option from environmental and customer perspectives.
6-3 Organisation Type of Response How response has been Consultation considered Scottish EIA Scoping SEPA are satisfied with items scoped in and Response noted and the Environment Report; June out. SEPA expects all associated works outlined mitigations have been Protection 2020 required to facilitate the Proposed discussed within Section 6.5 of Agency (SEPA) Development (including vegetation clearance, this assessment. access track upgrades, temporary site compounds, water crossings) to be outlined and mitigations detailed in the EIA Report. Records provided by SEPA identified 16 These SEPA CAR abstractions Data request abstractions authorised at Registration level have been included in this via email; under The Water Environment (Controlled assessment. June 2020 Activities) (Scotland) Regulations (CAR)19 and 34 abstractions authorised under CAR at Licence level within a 2 km distance of the Proposed Development. Aberdeenshire EIA Scoping Aberdeenshire Council are satisfied with the Response noted. Council Report; June proposed scope of the EIA Report. 2020 195 PWS located within a 2 km distance of the These PWS have been included Data request Proposed Development in the Aberdeenshire in this assessment. via email; authority area. Data represents indicative June 2020 locations of properties served by a PWS. Perth and Kinross EIA Scoping Perth and Kinross Council is satisfied with Response noted. Council Report; June both the conclusions of the report and the 2020 recommended environmental topics that will be considered as part of the EIA report going forward. These PWS have been included Data request 85 PWS located within a 2 km distance of the in this assessment. via email; Proposed Development in the Perth and June 2020 Kinross authority area. Angus Council EIA Scoping Angus Council are satisfied that the matters Response noted. Report; June relevant to the proposal are proposed to be 2020 scoped into the EIA. 27 PWS located within a 2 km distance of the These PWS have been included Data request Proposed Development in the Angus in this assessment. via email; authority area. Data represents indicative June 2020 locations of properties served by a PWS. Clackmannanshire Data request 8 PWS located within a 2 km distance of the These PWS have been included Council via email; Proposed Development in the in this assessment. June 2020 Clackmannanshire authority area. Dee District EIA Scoping Whilst we anticipate that some of the Response noted. GEMPs cover Salmon Fishery Report; June following construction methods may not be the topics of concern to Dee Board 2020 required it is relevant for us to mention them DSFB. A CEMP and ECoW will (Aberdeenshire) at this stage. The creation of pylon support the construction phase. foundations, access tracks, watercourse Dee DSFB contact information crossings, and the excavation of borrow pits will be included within the CEMP could result in increased sediment loading to and the ECoW will liaise with adjacent watercourses in the absence of Dee DSFB as required. suitable mitigation. Sediments will cause damage to aquatic invertebrates and fish through a smothering effect, reducing habitat availability and by interference with feeding and respiratory apparatus. Previous experience from large scale developments within the Don catchment for example the Transco Gas Pipeline and Aberdeen Western Peripheral Route, shows that although their initial assessments indicated that they would be able to control run off and had the capacity to manage
19 Scottish Environment Protection Agency. The Water Environment (Controlled Activities) (Scotland) Regulations 2011 (as amended). A Practical Guide. 6-4 Organisation Type of Response How response has been Consultation considered sediment effectively, during construction, even with high level mitigation measures in place, pollution was still prevalent and at a significant level. During this proposed development other risks are posed by pollution from hydrocarbons such as vehicle fuels and oils or from cementous materials during construction of the pylon bases and substation structures. Therefore, strict adherence to SEPA's Pollution Prevention Guidelines (PPG's) for work near watercourses is required. CIRIA guidance on the Control of Water Pollution from Construction Sites (SP156) should also be followed. Sediment and pollution control measures must always remain effective, all temporary detention ponds, swales, silt traps and other pollution prevention measures must be checked and maintained on a regular basis and particularly if periods of rain are forecast. This is relevant during and post works until the project is completed and the site has been fully commissioned.
Method of Baseline Data Collation To investigate baseline conditions and to consider potential effects of the Proposed Development with respect to hydrology, hydrogeology and soils a review of available desk-based information has taken place. The desk-based study involved a review of the Previous ES and the re-use of existing data where possible. A site walkover was undertaken for the Previous ES, therefore, no site visits have been undertaken for the purpose of this chapter. The general methodology used to assess the effect of the Proposed Development on the hydrology, hydrogeology and soils of the OHL Route and the surrounding area is as follows:
· Desktop study to obtain baseline and historical data; · Consultation with SEPA, Scottish Water and the Local Authorities to identify water abstractions and PWS;
· Identification of the potential effects of the Proposed Development on sensitive receptors; and · Identification of options for the mitigation of potential effects, taking account of the Applicant’s GEMPs (Appendix 3.2).
Determining Magnitude of Change and Sensitivity of Receptors The assessment of significance will consider the magnitude of change (from the baseline conditions), the sensitivity of the affected environment / receptors and (in terms of determining residual effects) the extent to which mitigation and enhancement will reduce or reverse adverse effects. Sensitivity of Receptor The sensitivity of the receptor will be determined using professional judgement, consideration of existing designations (such as SSSIs) and quantifiable data, where possible. The criteria used to determine the sensitivity of receptors are shown in Table 6-2.
6-5 Table 6-2: Sensitivity of Receptor Criteria
Sensitivity of Receptor
High · Surface Water Framework Directive (WFD) class ’High’. · Scottish Government DWPA. · Surface water or groundwater aquifer providing regionally important resources such as abstraction for public water supply, abstraction for PWS. · Supporting a site protected under EC or UK habitat legislation/species protected by EC legislation. · Protected Bathing Water Area. · Active floodplain with a possibility of direct flood risk to populated areas, construction workers, third parties and nearby developments which are sensitive to increased flood risk. · Highly dependent GWDTE. · Areas of deep peat (greater than 1.5m depth).
Medium · Surface water WFD class ’Good’ or ’Moderate’. · Surface water or aquifer providing water for agricultural or industrial use. · Local or regional ecological status / locally important fishery. · Moderately dependent GWDTE. · Non-peat soils.
Low · Surface water WFD class ’Poor’. · Unproductive strata / no abstractions for water supply. · Sporadic fish present.
Negligible · No aquatic habitats or watercourses present. · No commercial fisheries present. · No significant groundwater present.
Magnitude of Change The likely magnitude or extent of an impact (or change) on a receptor is established by assessing the degree of the impact relative to the nature and extent of the Proposed Development. The criteria used to determine the magnitude of change is shown in Table 6-3.
Table 6-3: Magnitude of Change Criteria
Magnitude of Change High Results in loss of attribute. Fundamental (long-term or permanent) changes to hydrology, hydrogeology and soils (e.g. resulting deterioration and change in the reclassification of watercourse status). Medium Results in effect on the integrity of attribute or loss of part of the attribute. Material but non- fundamental and short to medium term changes to the hydrology, hydrogeology and soils. Low Results in minor effect on the attribute. Detectable but non-material and transitory changes to the hydrology, hydrogeology and soils. Negligible Results in an effect on attribute but of insufficient magnitude to affect the use/integrity. No perceptible changes to the hydrology, hydrogeology and soils.
Probability
The probability of the occurrence of an effect has been evaluated as being high, medium or low during the phase of work being assessed. Professional judgement is used to determine the probability of occurrence.
6-6 The application of good practice and mitigation measures reduces the probability of an effect occurring. Significance The findings of the three criteria considered in the evaluation of an effect have been used via a matrix for each potential effect (Table 6-4) to assess the significance of an effect. Through the assessment, potential effects are concluded to be of major, moderate, minor or negligible significance. Major and moderate effects are considered significant and minor and negligible effects are considered not significant. Effects are considered adverse unless stated otherwise.
Table 6-4: Significance Matrix
Sensitivity Magnitude Probability Significance of Effect High Major High Medium Major Low Moderate High Moderate Medium Medium Moderate Low Minor High High Minor Low Medium Minor Low Minor High Minor Negligible Medium Negligible Low Negligible High Major High Medium Moderate Low Minor High Moderate Medium Medium Minor Low Minor Medium High Minor Low Medium Minor Low Negligible High Negligible Negligible Medium Negligible Low Negligible High Moderate High Medium Minor Low Negligible High Minor Low Medium Medium Minor Low Minor High Minor Low Medium Negligible Low Negligible
6-7 Sensitivity Magnitude Probability Significance of Effect High Negligible Negligible Medium Negligible Low Negligible High Negligible High Medium Negligible Low Negligible High Negligible Medium Medium Negligible Low Negligible Negligible High Negligible Low Medium Negligible Low Negligible High Negligible Negligible Medium Negligible Low Negligible
Limitations and Assumptions Baseline conditions have been established from a variety of sources, including historical data, but due to the dynamic nature of certain aspects of the environment, conditions will change during the construction and operation of the Proposed Development.
It is assumed that information received by third parties is complete and up to date. It is assumed that the design, construction and completed stages of the Proposed Development will satisfy minimum environmental standards, consistent with contemporary legislation, practice and knowledge.
6.3 Baseline Conditions Figure 6.1: Hydrology, Hydrogeology and Soils Baseline Conditions demonstrates the hydrology, hydrogeology and soils baseline conditions along the OHL Route.
Surface and Coastal Water Hydrology The OHL Route crosses 13 key river catchments20. The river catchment delineation is taken from the SEPA Scotland River Basin Management interactive map and is illustrated in Figure 6.1: Hydrology, Hydrogeology and Soils Baseline Conditions. Table 6-5 demonstrates the SEPA Water Framework Directive (WFD) classifications for watercourses within each of these 13 key river catchments. This was derived from the Water Classification Hub21.
Table 6-5: River Catchments and SEPA WFD Classifications
Catchment Status of surface waters (assessed for overall status) 2018 River Don Poor River Dee (Grampian) Moderate Kincardine and Angus Coastal High Bervie Water Poor
20 River Basin Management Plans Interactive Map, SEPA. Available at: https://www.sepa.org.uk/data-visualisation/water-environment-hub 21 Water Classification Hub. Available at https://www.sepa.org.uk/data-visualisation/water-classification-hub/ 6-8 Catchment Status of surface waters (assessed for overall status) 2018 River North Esk (Tayside) High River South Esk (Tayside) Good Perth Coastal Good River Tay Good River Earn Good Earn Coastal Moderate River Devon Moderate River Levan (Fife) Poor Stirling Coastal Moderate
The condition of watercourses along the OHL Route appear generally moderate or good. However, watercourses in the north beyond the River Dee are considered to be in poor condition. Therefore, the sensitivity of river catchments ranges from low to high. For the basis of this assessment, the river catchments will be assessed as high sensitivity receptors.
Flooding SEPA defines areas with a ‘High’ likelihood of flooding as being land within which a fluvial, coastal or pluvial flood event is likely to occur in the defined area on average once in every ten years (1:10); or a 10 % chance of occurrence in any one year. There are sections of the OHL Route located in areas subject to flooding, based on the SEPA indicative flood risk mapping22. Several of the tower locations are located in areas of flood risk, according to SEPA mapping, including towers in the floodplains of the River Dee, River Tay and River Earn. For example, Towers 493, 494 and 495 are located in the floodplain of the River Dee. These sites are considered to be of high sensitivity in relation to flooding based on a worst-case scenario.
Designated Sites This section details designated sites in relation to hydrology, hydrogeology and soils which are of regional, national or international importance, identified with reference to the NatureScot Sitelink website23, and within 1 km of the OHL Route. The designated sites outlined below are considered to be of high sensitivity as they are of international importance.
Special Areas of Conservation (SACs) There are three SACs associated with watercourses that the OHL Route passes over: the River Dee, River South Esk and River Tay. A common feature is the presence of Atlantic salmon. These sites would potentially be very sensitive to changes in water quality / turbidity.
22 SEPA Interactive Flood Risk Mapping. Available at http://map.sepa.org.uk/floodmap/map.htm 23 SNH website. .Available at https://sitelink.nature.scot/home 6-9 Pitkeathly Mires SAC / SSSI
Pitkeathly Mires is situated in a shallow valley on the north side of the Ochil Hills, at a height of around 250 m and is intersected by the OHL Route. The site was selected as a SSSI for its series of upland basin mires which contain extensive and undisturbed areas of nutrient-poor and intermediate fen and flush vegetation. The fens are waterlogged habitats fed by infiltrating water from the surrounding land and dominated by sedges and mosses. Moss-dominated flushes occur where water seeps out of the ground and before it has resolved itself into a burn. The SSSI also contains a sizeable area of heath land (which has become increasingly scarce in the Ochil Hills) and a small artificial loch. The site is relatively undisturbed in comparison with other similar areas, due to a lack of agricultural improvement or afforestation upslope from the site in the past.
The site is also designated as a SAC under the Habitats Directive for the very wet mires often identified by an unstable ‘quaking’ surface, and the slender green feather-moss Drepanocladus vernicosus (now known as varnished hook-moss Hamatocaulis vernicosus).
North Esk and West Water Palaeochannels (SSSI) North Esk and West Water Palaeochannels (SSSI) is intersected by the OHL Route. This site provides an excellent example of an assemblage of Quaternary (Ice Age) and fluvial (river) landform formed at the end of the last glaciation. It includes melt water channels, moraines and a particularly fine example of sandur (glacial outwash plain) sediments which have been dissected to form four main terrace systems.
The site also demonstrates three types of palaeochannel (relict river channels) associated with different fluvial processes on a single terrace surface. Each of the terrace systems exhibits well developed, braided palaeochannel networks. The individual terraces are also locally incised by relatively well defined, low gradient, sinuous channels and conspicuous meander scars. In addition, there are deeper, wider channels, possibly cut by melt waters draining off stagnant ice, and clear inter- terrace changes in palaeochannel form. As well as demonstrating landforms of deglaciation, the site also reveals the altering river processes and channel changes that occurred during and following the melting of the last ice sheet.
Geology British Geological Survey 1:625,000 bedrock geology mapping indicates the Proposed Development crosses a variety of bedrock types. These include: · Unnamed Igneous Intrusion, Late Silurian to Early Devonian – Felsic Rock;
· Southern Highland Group – Psammite and Pelite; · Stonehaven Group – Sandstone with Subordinate Conglomerate and Siltstone; · Strathmore Group – Sandstone with Subordinate Conglomerate, Siltstone and Mudstone;
· Unnamed Extrusive Rocks, Silurian to Devonian – Mafic Lava and Mafic Tuff; · Inverclyde Group – Sandstone, Siltstone and Mudstone; and · Scottish Coal Measures Group – Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete.
Several fault lines are recorded in the area. British Geological Survey 1:625,000 superficial geology mapping indicates the Proposed Development crosses a variety of superficial deposits. These include:
· Peat; · Glacial Sand and Gravel; · Alluvium; and
6-10 · Till.
British Geological Survey 1:625,000 mapping indicates the OHL Route crosses moderately productive and low productivity aquifers in which flow is virtually all through fractures and other discontinuities. The OHL Route crosses numerous groundwater bodies with range of poor to high WFD status classifications. The Scottish Government Drinking Water Protected Areas – Scotland river basin district: maps24 indicate that the OHL Route crosses both Ground and Surface Water DWPAs. As the groundwater bodies are part of a DWPA their sensitivities are high in relation to water quality.
Public and Private Water Supplies Scottish Water confirmed, through their scoping response, that the Proposed Development crosses a drinking water catchment where a Scottish Water abstraction is located, which is required to be protected in terms of water quality and quantity. This is an abstraction from the River Tay which supplies Perth Gowans Terrace Water Treatment Works (WTW) (as shown on Figure 6.1 Hydrology, Hydrogeology and Soils Baseline Conditions), as indicated by Scottish Water in their scoping response. The River Tay, at its closest point is approximately 100 m from the nearest proposed access track and this is therefore the minimum possible distance from the abstraction. A consultation response regarding any further Scottish Water registered assets located within a 2 km distance of the OHL Route was not received. Wi2 km distance of the OHL Route, there are 16 abstractions which are CAR Registration authorised, three of which are located within 250 m of the indicative construction access routes, with one of these within 250 m of one of the 73 towers requiring extension. There are 34 abstractions which are CAR Licence authorised within 2 km, eight of which are within 250 m of the indicative construction access routes. SEPA abstraction locations are to be used for indicative purposes only. Records provided by the local councils indicate that there are many PWS located within 2 km of the OHL Route.
Several of the PWS are located within 250 m of the indicative construction access routes. For example, there are approximately 19 supplies within this distance in Perth and Kinross Council, six within Angus Council, 67 within Aberdeenshire Council and none within Clackmannanshire Council. Four supplies in Aberdeenshire Council are located within 250 m of one of the 73 towers requiring extension. Note that Angus and Aberdeenshire data represents indicative locations of properties served by a PWS.
The supplies located within 250 m of the indicative construction access routes or of one of the 73 towers requiring extension have been identified in Table 6-6 and Table 6-7 with the location of these shown on Figure 6.1: Hydrology, Hydrogeology and Soils Baseline Conditions.
The supplies are considered to be of high sensitivity.
Table 6-6: PWS Within 250 m of the Indicative Construction Access Routes or a Tower Requiring Extension
PWS Name Local Authority Coordinates Source Type of Council supply Wester Model Cottage Perth and Kinross 322487, 743234 Not specified Type B Supply Coupar Grange Supply Perth and Kinross 322400,743000 Borehole Type B
24 Scottish Government Drinking Water Protected Areas – Scotland river basin district: maps. Available at: https://www.gov.scot/publications/drinking-water- protected-areas-scotland-river-basin-district-maps/ 6-11 PWS Name Local Authority Coordinates Source Type of Council supply Hatton of Cargill Farm Perth and Kinross 317277, 737928 Not specified Type B Cottage Hatton of Cargill Supply Perth and Kinross 316900, 736500 Spring Type B Mavisbank Supply Perth and Kinross 313163, 730720 Spring Type B Woodhead of Mailer Perth and Kinross 309400,720800 Borehole Type B Borehole Supply Woodhead of Aberdalgie Perth and Kinross 309265, 720726 Not specified Type B Supply Rossie Ochil Supply Perth and Kinross 309900, 712800 Spring Type A1 Easter Deuglie Supply Perth and Kinross 311900, 710800 Spring Type B Abbots Deuglie Supply Perth and Kinross 311849, 710828 Not specified Type B Middle Deuglie Farm Perth and Kinross 312030, 710899 Well Type B Supply Goudierannet Supply Perth and Kinross 311900, 710500 Borehole Type B Glendy Borehole Supply Perth and Kinross 312500, 709800 Borehole Type B Newhill Farm Supply Perth and Kinross 311600, 708300 Surface watercourse Type A1 Holton Dairy Farm Supply Perth and Kinross 311300, 707200 Spring Type A1 Nether Tillyrie Supply Perth and Kinross 311200, 707200 Spring Type B Upper Tillyrie Supply Perth and Kinross 311200, 707100 Spring Type B Craigowmill Steading Perth and Kinross 308800,705600 Borehole Type B Borehole Nether Gelvan Supply Perth and Kinross 305500, 701500 Surface watercourse Type B Pitmudie Farm Angus 354695, 767175 Spring Type B Leightnie Bothy & Hut Angus 352586, 767708 Spring Type B Tillybirnie Angus 351160, 766318 Spring Type B Afflochie Angus 347613, 764285 Spring Type B Soutra Farmhouse Angus 344683, 760992 Spring Type B Red Hall, Glen Prosen Angus 338769, 758145 Spring Type B Hillcrest Aberdeenshire 377067, 814090 Not specified Type B Dewsford Farm House, Aberdeenshire 376510, 814112 Not specified Type B Leylodge Dewsford Cottage, Aberdeenshire 376453, 814090 Well Type B Leylodge Heath View Aberdeenshire 375196, 812629 Not specified Type B Whinn Dale Aberdeenshire 375138, 812699 Not specified Type B Drumnaheath Cottage Aberdeenshire 375027, 812673 Not specified Type B Drumnaheath Aberdeenshire 375381, 812526 Well Type B 5 Barnyards Of Aberdeenshire 375401, 812516 Not specified Type B Drumnaheath 3 Barnyards Of Aberdeenshire 375395, 812498 Not specified Type B Drumnaheath 2 Barnyards Of Aberdeenshire 375402, 812492 Not specified Type B Drumnaheath
6-12 PWS Name Local Authority Coordinates Source Type of Council supply 1 Barnyards Of Aberdeenshire 375414, 812499 Well Type B Drumnaheath Lauchentilly Cottage Aberdeenshire 374497, 812535 Not specified Type B Nether Lauchentilly Aberdeenshire 374407, 811906 Not specified Type B Nether Lauchentilly Aberdeenshire 374384, 811880 Not specified Type B Cottage Bogendinnie Aberdeenshire 374725, 811237 Well Type B Backhill Of Glack Aberdeenshire 374227, 810691 Not specified Type B Achath Cottage South Aberdeenshire 373291, 811028 Spring Type B Acath House Aberdeenshire 373258, 811039 Spring Type B Achath Aberdeenshire 373176, 810963 Not specified Type B West Burnseat Aberdeenshire 372797, 809681 Well Type B Old Toll House Aberdeenshire 372711, 809693 Not specified Type B Mill Of Kinnernie Aberdeenshire 372561, 809560 Not specified Type B Old Manse Aberdeenshire 372527, 809595 Not specified Type B Oldtown Aberdeenshire 372462, 809582 Not specified Type B Broomhill Cottage Aberdeenshire 372545, 809359 Not specified Type B East Burnseat Aberdeenshire 373330, 809655 Well Type B Middle Broomhill Aberdeenshire 372645, 808848 Well Type B Nethermuir Cottage Aberdeenshire 372142, 808928 Not specified Type B Upper Broomhill Aberdeenshire 372350, 807958 Not specified Type B Hillside Aberdeenshire 372092, 807227 Not specified Type B Newseat Cottage Aberdeenshire 372473, 806396 Not specified Type B Upper Mains Cottage Aberdeenshire 373272, 806473 Not specified Type B Upper Mains Aberdeenshire 373534, 806426 Not specified Type B Greentree Croft Aberdeenshire 372860, 805537 Not specified Type B Sandyhillock Aberdeenshire 373523, 804538 Not specified Type B Hillbrae Cottage Aberdeenshire 373585, 804129 Not specified Type B Birks Of Cullerlie Aberdeenshire 374255, 802540 Spring Type B Birks Of Cullerlie Cottage Aberdeenshire 373997, 802463 Not specified Type B Cairnview Aberdeenshire 376305, 797007 Not specified Type B Wester Durris Aberdeenshire 376886, 796142 Not specified Type B Milton Aberdeenshire 377017, 795867 Not specified Type B No. 1 Cottage Aberdeenshire 377138, 784748 Not specified Type B Brae Schoolhouse Aberdeenshire 375785, 783704 Spring Type B Lawgavin Cottage Aberdeenshire 375764, 783603 Not specified Type B Goosecruives Steading Aberdeenshire 375815, 783187 Not specified Type B Wester Cotbank Aberdeenshire 375827, 783156 Not specified Type B Milton Of Dellavaird Aberdeenshire 373535, 781693 Not specified Type B Ash Cottage Tipperty Aberdeenshire 372947, 781696 Not specified Type B Elm Cottage Aberdeenshire 372933, 781690 Not specified Type B
6-13 PWS Name Local Authority Coordinates Source Type of Council supply Templehill Log House Aberdeenshire 372238, 781202 Spring Type B The Old Rectory Aberdeenshire 371630, 779726 Not specified Type B Drumtochty Drumelzie Cottage Aberdeenshire 371422, 779286 Spring Type B 2 Newbigging Cottages Aberdeenshire 364517, 776285 Not specified Type A 4 Newbigging Cottages, Aberdeenshire 364469, 776251 Not specified Type A Fasque 2 Broomwood Cottages Aberdeenshire 364664, 775875 Not specified Type A 1 Broomwood Cottages Aberdeenshire 364652, 775869 Not specified Type A Gardeners Bothy Aberdeenshire 364611, 775969 Not specified Type A Avenue Cottage Aberdeenshire 364801, 775793 Spring Type A Coachmans House, Aberdeenshire 364683, 775768 Not specified Type A Fasque Delalie Aberdeenshire 363404, 775794 Spring Type B East Mains Of Balfour Aberdeenshire 361812, 774353 Spring Type B Laundry Cottage Aberdeenshire 361253, 774147 Not specified Type B Mains Of Balfour Aberdeenshire 361251, 774134 Spring PWS Supply Kirkton Of Balfour Aberdeenshire 360326, 773450 Not specified Type B Westerton Of Balfour Aberdeenshire 361096, 773891 Spring Type A (Westerton Cottages) Balfour Bungalow Aberdeenshire 361254, 773814 Spring Type B Bonharry Farm Aberdeenshire 359528, 773124 Not specified Type B
Table 6-7: SEPA Authorised Abstractions within 250 m of the Indicative Construction Access Routes or a Tower Requiring Extension
Supply Name Authorisation Licence Number Coordinates Former Dunecht Village Water Supply CAR Registration CAR/R/1014418 372986, 809438 Jacksbank, Drumlithie, Stonehaven CAR Registration CAR/R/1082125 376632, 783282 A9/A85 Junction to Bertha Park, Perth CAR Registration CAR/R/1157829 308270, 726583 Kinnaniel Farm, Kingoldrum, Kirriemuir CAR Licence CAR/L/1004742 332012, 753155 Balmyle Farm, Meigle, Perthshire CAR Licence CAR/L/1010198 327581, 744503 Coupar Grange Estate CAR Licence CAR/L/1004653 322364, 742995 Islabank Farm, Coupar Angus CAR Licence CAR/L/1010036 319999, 741221 Hallhole Farm, Coupar Angus CAR Licence CAR/L/1009906 317993, 739234 Loanhead Farm, St Martins, Perth CAR Licence CAR/L/1010070 314358, 732624 Ardgilzean, Old Scone, Perth PH2 6AD CAR Licence CAR/L/1012089 312628, 729515 Denmarkfield Farm CAR Licence CAR/L/1009705 309587, 728407
6-14 Soils The UK Soil Observatory mapping25 indicates the OHL Route crosses two Nitrate Vulnerable Zones. These are: · Aberdeenshire, Banff, Buchan; and
· Moray, Strathmore and Fife. There are areas of peat located along the OHL route. Based on a review of UK Soil Observatory mapping, the National Soil Map of Scotland interactive mapping26 and SNH Carbon and Peatland mapping27, it is indicated that the towers located in areas of peat include Towers 469 – 479, 496, 509 and 511. The route generally avoids areas of extensive peat coverage and peat that has been identified is limited to discrete areas throughout the route. These sites are considered to be of high sensitivity, based on the precautionary assumption that deep peat (greater than 1.5m depth) may be present in these localities.
Groundwater Dependent Terrestrial Ecosystems A Phase 1 Habitat Survey was completed by the WSP Ecology team which obtained National Vegetation Classification (NVC) survey data on the potential GWDTE28 within Pitkeathly Mires SAC / SSSI, as demonstrated in Appendix 7.3, Figure 7.3.1. The basin fens of Pitkeathly Mires, comprising NVC communities M9, a base-poor small sedge and Schoenus community, and S27, a tall-herb fen community, are good examples of hydroseral zonation, identified by an unstable ‘quaking’ surface due to layers of peat separated by lenses of water. The basin fens are connected to M23a, a fen-meadow / rush-pasture community, which extends under the OHL Route and there are discrete patches of MG9, a widespread community associated with poorly drained permanent pastures. Regardless of their reliance on groundwater specifically, it is anticipated that wet mire habitat throughout Pitkeathly Mires and the surrounding undesignated mire habitats are dependent on a functioning hydrological regime. The dry heath and acid grassland communities at Pitkeathly Mires are assumed to be fed by rainwater alone, with no springs observed within areas of dry heath under the OHL Route. It is not anticipated that there will be any ground excavation associated with the Proposed Development that would disrupt the supporting hydrological processes of Pitkeathly Mires SAC and SSSI.
Fisheries Several fisheries important for sustaining salmonid populations are located along the OHL Route. The route crosses or extends adjacent to watercourses which support salmon and trout populations including the River Dee SAC, River South Esk SAC and River Tay SAC. The River Tay, for example, is internationally famous for its Atlantic salmon fishing. The River Isla and Burn of Drum are both within the Deveron Fisheries District and there are stocks of Atlantic salmon, sea trout and brown trout. Restocking takes place within the River Isla and there is no commercial netting in operation within the fishery district at this present time. The above watercourses are considered to be of high sensitivity with regards to fisheries.
25 UK Soil Observatory mapping. Available at: http://mapapps2.bgs.ac.uk/ukso/home.html 26 the National Soil Map of Scotland interactive mapping. Available at: https://map.environment.gov.scot/Soil_maps/?layer=1 27 SNH Carbon and Peatland map. Available for download at: https://gateway.snh.gov.uk/natural-spaces/dataset.jsp?dsid=PEAT 28 plant communities reliant on constant water movement typically identified through a combined assessment of topography, geohydrology and botany 6-15 Future Baseline There is potential for climate change to impact on future baseline conditions. Climate change studies predict a decrease in Summer precipitation and an increase in Winter precipitation alongside slightly higher annual average temperatures. This suggests that there may be greater pressures on PWS in Summer months in the future. Storms are predicted to be of greater intensity, therefore, peak fluvial flows associated with extreme storm events may also increase in volume and velocity.
Sensitive Receptors Table 6-8 summarises the sensitive receptors which have been assessed.
Table 6-8: Sensitivity of Receptors
Receptor Sensitivity River Catchments All High GWDTE Pitkeathly Mires SAC / SSSI High Groundwater bodies DWPA High Low Productivity Aquifer Medium Moderately Productive Aquifer High WFD Poor classification groundwater body Low WFD Good classification groundwater body High Ecological Designations River Dee SAC High River South Esk SAC High River Tay SAC High Pitkeathly Mires SAC / SSSI High North Esk and West Water Palaeochannels SSSI High Flooding (fluvial) Construction workers, local residents, third parties and nearby developments High Public and Private Water Supplies High Fisheries River Dee SAC High River South Esk SAC High River Tay SAC High Peat Deposits High Local Soils Medium
6.4 Issues Scoped Out Operational impacts have been scoped out of this assessment as there are not expected to be any impacts that are likely to be significant from the operation of the Proposed Development. This is because the Proposed Development will use the existing infrastructure (i.e. no new towers will be introduced) and the operational requirements (e.g. maintenance) will be unchanged and therefore there will be no impact on hydrology, hydrogeology and soils after completion of the construction phase.
As the project concerns upgrading and refurbishment of existing structures, decommissioning is not considered applicable and is scoped out of the EIA.
6-16 The impact of the mobilisation of contaminated soil / bedrock has been scoped out as any rural environmental contaminated soil mobilisation is unlikely along the OHL Route. A formal Peat Landslide Hazard and Risk Assessment (PLHRA) has been scoped out of the EIA due to the limited anticipated effects associated with the Proposed Development and a more proportionate assessment of the effects on peat stability has been included.
6.5 Assessment of Effects, Mitigation and Residual Effects
Mitigation by Design The opportunity to influence the design of the Proposed Development as part of hydrology, hydrogeology and soils mitigation has been limited because the towers and OHL Route are already in existence (which limits any potential effect); and the exact location of temporary infrastructure (e.g. compounds) will be at the discretion of the Principal Contractor(s).
Access tracks will be required across watercourses to undertake tower reinforcements and string conductors. The detailed access requirements are outlined in Chapter 3: Description of the Proposed Development.
The location and layout of welfare facilities etc. will also be the responsibility of the Principal Contractor(s) and would be confirmed within and based upon principles detailed within the CEMP prior to construction commencing. For example, in order to avoid the potential for direct discharges of untreated foul sewage from temporary welfare facilities to watercourses or water bodies, welfare facilities would either drain to a portable septic tank or connect directly to the foul sewer such that there would be no significant impact.
Design Solutions and Assumptions Access would be required to each tower for delivery of fittings, fixtures, working platforms and plant. Access requirements to each tower would depend on the tower type and the operations required at the tower. The proposed access routes to each tower location are illustrated on Figure 3.1. Existing tower access routes utilised by the Applicant’s operation and maintenance teams and for the earthwire replacement works previously undertaken would be used whenever possible. Many individual tower sites would be accessible from public roads and farm tracks and in such circumstances normal site vehicles such as 4x4 Hiab wagons, transit vans, 4x4 pickup trucks, quad bikes and tractors would be utilised. Where there are no public roads or farm tracks, should ground conditions permit, it may be possible in dry weather for the vehicle types indicated above to gain access to certain sites without causing ground surface damage. If damage is likely it may be necessary to undertake access upgrades to allow the use of the above vehicles, or alternatively to use specialist low ground bearing pressure vehicles.
Access upgrades and protection can be undertaken in a number of ways. The preferred method for each site would be selected by the successful Principal Contractor(s) based on the suitability to withstand expected construction loads, cause least environmental damage and be installed / recovered at the lowest cost. The range of construction access options likely to be considered include: · Installation of temporary metal or plastic roadway panels (e.g. Trakway); · Installation of temporary stone roads on a geo-textile fabric base; · Patching of existing accesses (for light use only); or · Use of specialised low ground bearing pressure vehicles.
6-17 There are 73 towers which require extensions of up to 10% of their existing height. These locations are shown on Figure 3.2 and the proposed tower height increases are detailed in Chapter 3: Description of the Proposed Development. To facilitate construction of a tower extension requires either an outage on both circuits of the OHL Route or the need for a temporary diversion. The temporary diversion would use temporary masts, as the preferred option, which would be located within 100 m of the OHL Route. However, temporary conventional towers may be used if space is limited for the stays. Temporary stone roads/crane pads would be required to erect temporary towers.
Construction Good Practice A number of Good Practice Measures are detailed in Chapter 3 – Section 3.3 including the CEMP and GEMPs (GEMPs are provided in Appendix 3.2). A summary of those most relevant to hydrology, hydrogeology and soils of the OHL Route is provided below. The adoption of the applicable GEMPs would reduce the probability of an incident occurring and also reduce the magnitude of any incident due to a combination of good Site environmental management procedures, including minimised storage volumes, soil management, staff training, contingency equipment and emergency plans.
The GEMPs (Appendix 3.2) applicable to this chapter are: · Working in or near water GEMP; · Working in sensitive habitats GEMP; · Watercourse crossings GEMP; · Private water supplies GEMP; · Soil Management GEMP; · Oil storage and refuelling GEMP; and · Bad weather GEMP. The following assessment of effects assumes that the measures contained within these GEMPs are implemented.
Description of Effects During the construction phase of the Proposed Development, there is the potential for the following short-term impacts on the hydrology, hydrogeology and soils environment in the absence of additional mitigation measures. Pollution of surface watercourses, groundwater and water supplies This includes impacts from suspended sediment in surface water bodies, hydrocarbon and oil pollution. Potential sources of suspended sediments on the site include from the access track formation, including the temporary stone roads, temporary construction compounds and excavations from foundation reinforcement works. These works may be required where engineering studies indicate that the existing foundations are not strong enough to support the new conductors, including the 73 towers requiring extension. Major causes of environmental harm associated with working in or near watercourses include: · Silt e.g. disturbance of riverbed or bank, dewatering and pumping of excavations, run-off from exposed ground, plant washing, roads and river crossings; · Cement and concrete – which is very alkaline and corrosive and can cause serious pollution; · Chemicals and solvents – oil storage, refuelling, trade materials etc; and · Waste materials (including special waste) e.g. oily wastes, spent acids and solvents.
6-18 Taking into account the design and embedded mitigation, specifically the working in or near water, watercourse crossings, private water supplies, soil management, oil storage and refuelling, and bad weather GEMPs, the effects have been assessed as follows: · Rated as high sensitivity, the magnitude of pollution effect of surface watercourses is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant). · Rated as high sensitivity, the magnitude of pollution effect of groundwater bodies is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant). · Rated as high sensitivity, the magnitude of pollution effect of PWS is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant).
PWS will require further investigation prior to construction in order to verify indicative locations of supply sources provided by the relevant local authority, the supply type, properties supplied and their uses in line with the PWS GEMP. Consultation will be required with property owners as part of this process and further unregistered supplies may need to be established through further consultation with local property owners. The Principle Contractor(s) will be required to consider all construction activities and satisfy themselves that they are aware of all PWS in the local area that may be at risk of adverse effects as a result of the Proposed Development. Should any PWS be identified which require protection, specific mitigation will be developed through the CEMP, which will be agreed with SEPA. Further consultation with Scottish Water is required prior to construction to identify any Scottish Water assets which require protection. Should any such assets be identified, specific mitigation measures will be development and incorporated into the CEMP, which will be agreed with SEPA. Impact on water resource availability
This includes impacts to the groundwater bodies, PWS, peat deposits and the GWDTE from any dewatering required. This effect is likely to be of negligible magnitude as there are no cut tracks and only very minor excavations are being undertaken where there are already foundations located.
Taking into account the design and embedded mitigation, specifically the watercourse crossing and private water supplies GEMPs, the effects have been assessed as follows: · Rated as high sensitivity, the magnitude of the impact on water resource availability to groundwater bodies is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant); · Rated as high sensitivity, the magnitude of the impact on water resource availability to PWS is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant); · Rated as high sensitivity, the magnitude of the impact on water resource availability to peat is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant); and · Rated as high sensitivity, the magnitude of the impact on water resource availability to Pitkeathly Mires SAC / SSSI GWDTE is considered high and of low probability to occur, giving an overall significance of Moderate Adverse (significant).
Impact of pollution on fisheries This includes potential sources of pollution from the access track formation, including the temporary stone roads, temporary construction compounds and excavations from the work to the towers requiring foundation reinforcement works. This is required where engineering studies have indicated that the existing foundations are not strong enough to support the new conductors.
6-19 Taking into account the design and embedded mitigation, specifically the working in or near water, watercourse crossings, soil management, oil storage and refuelling and bad weather GEMPs, the effects have been assessed as follows: · Rated as high sensitivity, the magnitude of the impact of pollution on fisheries is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant).
Short term increase in flood risk This includes impacts to construction workers, third parties and nearby developments and floodplains from the obstruction of watercourses during construction and the increased runoff due to soil compaction. Taking into account the design and embedded mitigation, specifically the watercourse crossings GEMP, the effects have been assessed as follows: · Rated as high sensitivity, the magnitude of the impact of a short term increase in flood risk on third parties and nearby developments is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant); and · Rated as high sensitivity, the magnitude of the impact of a short term increase in flood risk on floodplains construction workers is considered high (as there may be works undertaken in areas of flood risk) and of low probability to occur, giving an overall significance of Moderate Adverse (significant). Soil erosion, compaction and excavation losses This includes impacts to the local soils during the construction activities and access track formation including temporary stone roads where heavier equipment is needed. The effect is likely to be of low magnitude due to the minimal excavations required which are either limited to tower foot locations or for temporary crane pads for the 73 towers requiring extension.
Taking into account the design and embedded mitigation, specifically the watercourse crossings and soil management GEMPs, the effects have been assessed as follows: · Rated as medium sensitivity, the magnitude of the impact of erosion, compaction and excavation losses on local soils is considered low and of low probability to occur, giving an overall significance of Negligible (not significant).
Loss of peat soils This includes impacts to peat soils and Pitkeathly Mires SAC / SSSI GWDTE due to construction activities and access track formation including temporary stone roads where heavier equipment is needed. Taking into account the design and embedded mitigation, specifically the watercourse crossings, soil management and sensitive habitats GEMPs, the effects have been assessed as follows: · Rated as high sensitivity, the magnitude of the impact of a loss of peat is considered low and of low probability to occur, giving an overall significance of Minor Adverse (not significant); and · Rated as high sensitivity, the magnitude of the impact of loss of peat soils on Pitkeathly Mires SAC/SSSI GWDTE is considered high and of low probability to occur, giving an overall significance of Moderate Adverse (significant).
6-20 Peat Instability Given the very limited locations where peat is anticipated to be present and the limited degree of disturbance likely to be associated with the Proposed Development, there is opportunity to avoid discrete areas identified of concern by utilising data collated during pre-construction Ground Investigation (GI) to inform the micrositing of temporary towers and access routes. It was not considered appropriate to undertake a more formal PLHRA, given that the proposed works with the potential to impact upon peat are limited to existing tower foundation works, steel reinforcement works and associated track upgrades. Works relating to the tower extensions are considered more likely to present a risk of disturbance of peat due to the requirement for the construction of one or more temporary towers and any associated access tracks. However, the desk-based review has identified that the areas where peat is indicated to be present is limited to four of the 73 tower extension locations. At the pre-construction stage, further peat data will be collected at the four tower extension locations and mitigation measures within the Applicant’s relevant GEMP, specifically the Working in Sensitive Habitats GEMP, which includes specific measures for working in peatland and peat management, will be implemented. Any further site-specific measures will also be identified and implemented, as necessary. At discrete tower locations where peat is present, the receptor sensitivity is high. Evaluation of magnitude of effect has taken account of appropriate good practice, GI, data interpretation, and associated detailed design updates in advance of construction activities on towers, and any requirements for track construction in such localities. It is therefore considered that the magnitude of effect on soils / peat would be medium, with a low probability of occurrence, resulting in an overall significance of Minor Adverse (not significant). It is considered that the effect on surface water receptors in these locations would have equivalent levels of sensitivity, magnitude and probability, to also result in a Minor Adverse significance outcome at the construction phase.
Impacts upon GWDTE This includes impacts from excavation during the construction phase causing localised disruption and interruption to groundwater flow. As excavations are limited to either tower foot foundations where the foundation is already present, or temporary crane pads of limited extent for the 73 towers requiring extension, the effect on the GWDTE is likely to be of negligible magnitude. Interruption of groundwater flow would potentially reduce the supply of groundwater to GWDTEs thereby causing an alteration / change in the quality or quantity of and / or the physical or biological characteristics of the GWDTE. Contamination of groundwater may also cause physical or chemical contamination of the GWDTE.
Taking into account the design and embedded mitigation, specifically the working in sensitive habitats GEMP, the effects have been assessed as follows: · Rated as high sensitivity, the magnitude of the impact on Pitkeathly Mires SAC / SSSI GWDTE is considered high and of low probability to occur, giving an overall significance of Moderate Adverse (significant).
Mitigation During Construction Due to the nature of the re-conductoring works the effects of the Proposed Development are very limited. In general, most effects are of low magnitude and not significant, after the implementation of embedded mitigation. Specific mitigation measures are summarised below (mitigation reference ‘HG’ corresponding with Chapter 12: Schedule of Mitigation).
6-21 HG1: Following further investigation of PWS and consultation with property owners prior to construction, should any PWS be identified which require protection, specific mitigation will be developed through the CEMP, which will be agreed with SEPA. HG2: The Pitkeathly Mires Access Method Statement, as presented in Appendix 7.3: Pitkeathly Mires National Vegetation Classification Survey Report, must be fully adhered to. HG3: With regard to works within areas identified as having a ‘High’ likelihood of flooding on the SEPA Flood map22, construction works would not take place during extreme flood conditions or in floodplain areas that are inundated, or where such conditions are forecast. Careful consideration will be given to any earthwork activities scheduled during the winter period or other periods where saturated soils are likely to occur.
HG4: GI will be undertaken at locations where ground works are required at locations to be confirmed by the Principal Contractor(s), this will include the four tower extension locations identified in areas of peat and stone access tracks. A Geotechnical Risk Register (GRR) will be prepared and updated as the project progresses, including any identified risk locations in relation to peat instability. HG5: Undertake consultation with Scottish Water prior to construction to identify any Scottish Water assets which require protection. Should any such assets be identified, specific mitigation measures will be development and incorporated into the CEMP, which will be agreed with SEPA. Monitoring HG6: Mitigation measures would be monitored by an Environmental Clerk of Works (ECoW) throughout construction. Should any peat stability risk locations be identified in the GRR, these areas will be monitored appropriately, prior to and during construction.
Residual Effect After the implementation of mitigation measures, the magnitude of the impacts to water resource availability, from loss of peat soils, and impacts to GWDTE on Pitkeathly Mires SAC / SSSI GWDTE are considered low and of low probability to occur, giving overall significance of Minor Adverse (not significant). After the implementation of mitigation measures, the magnitude of a short-term increase in flood risk on construction workers is considered low and of low probability to occur, giving overall significance of Minor Adverse (not significant). Therefore, no potentially significant effects have been identified during the construction phase.
Operational Phase All operational impacts are scoped out of this assessment as there is not expected to be any impacts that are likely to be significant from the operation of the Proposed Development.
Cumulative Effects Chapter 5: Methodology identifies other developments to be considered as having potential for cumulative impact with the Proposed Development. Even in the event that these other developments present potentially significant impacts to the receiving hydrology, hydrogeology and soils environment, given that no significant residual impacts have been identified associated with the Proposed Development, and considering that the nature of works are likely to be minimal for this OHL upgrade project, significant cumulative impacts are not anticipated.
6-22 6.6 Summary The following sensitive hydrology, hydrogeology and soils receptors along the OHL Route have been identified: · River Catchments - River Don, River Dee (Grampian), Kincardine and Angus Coastal, Bervie Water, River North Esk (Tayside), River South Esk (Tayside), Perth Coastal, River Tay, River Earn, Earn Coastal, River Devon, River Levan (Fife) and Stirling Coastal; · GWDTE - Pitkeathly Mires SAC / SSSI; · Groundwater bodies - DWPA, Low Productivity Aquifer, Moderately Productive Aquifer, WFD Poor classification groundwater body, WFD Good classification groundwater body; · Ecological designations - River Dee SAC, River South Esk SAC, River Tay SAC, Pitkeathly Mires SAC / SSSI and North Esk and West Water Palaeochannels SSSI; · Flooding (fluvial) – construction workers, third parties and nearby developments; · Public and Private Water Supplies; · Fisheries - River Dee SAC, River South Esk SAC and River Tay SAC; · Peat Deposits; and · Local Soils. This chapter considered how the Proposed Development would affect the above sensitive receptors. Through successful application of the embedded and additional, secondary mitigations identified, this chapter concludes that the Proposed Development would not result in a residual significant effect on any of the sensitive hydrology, hydrogeology and soils receptors. Mitigation measures would be monitored by an Environmental Clerk of Works (ECoW) throughout construction.
6-23 7 BIODIVERSITY
7.1 Introduction This chapter assesses the potential effects on biodiversity (encompassing ecology and ornithology) resulting from the Proposed Development. This chapter is accompanied by the following Figures and Appendices: · Figure 7.1: Designated Sites; · Appendix 7.1: Extended Phase 1 Habitat and Protected Species Survey Report; · Appendix 7.2: Confidential Badger Data; · Appendix 7.3: Pitkeathly Mires National Vegetation Classification Survey Report; · Appendix 7.4: Bird Consultation Results; · Appendix 7.5: Confidential Bird Data; and · Appendix 7.6: Biodiversity Legislation and Planning Policy.
A distinct report addressing a Habitats Regulations Appraisal of the Proposed Development has also been prepared.
7.2 Assessment Methodology and Significance Criteria
Scope of the Assessment An EIA Scoping Report was submitted in June 2020, which outlined the scope of this Ecological Impact Assessment (EcIA) based on the available baseline data at the time (see Appendix 4.1: EIA Scoping Report). Subsequently, further consultation was undertaking in relation to the design requirement for increased tower heights (see Appendix 4.3: Tower Extension Scoping Consultation). The scope has since been revised to incorporate the Scoping Responses from various stakeholders (see Table 7-7-1 below). Any deviations are identified and justified accordingly. This chapter focusses on the effects of the construction phase of the Proposed Development upon Important Ecological Features (IEF) aligning with EcIA Guidelines from the Chartered Institute of Ecology and Environmental Management29 (hereafter the ‘CIEEM EcIA Guidelines’). This EcIA has also been prepared with reference to the applicable legislative framework and national and local planning policy; these are outlined in Appendix 7.6: Biodiversity Legislation and Planning Policy. Specific guidance documents for habitats and species are referenced throughout this chapter and the associated Appendices as appropriate.
Extent of the Study Area Distinct study areas have been established for desk-based data review exercises and field surveys, to reflect the different elements of the Proposed Development, ecological sensitivities along the OHL Route and extent of the Proposed Development’s Ecological Zone of Influence (EZoI). The CIEEM EcIA Guidelines define the EZoI as the area over which ecological features may be subject to significant effects as a result of the Proposed Development; this could extend beyond the footprint of the Proposed Development (‘transboundary effects’). The EZoI will vary for each ecological feature due to the varying mobility range of the feature being assessed. For example, the EZoI for birds, otters and badgers (which are more mobile) will be greater than the EZoI for habitats (which are sedentary).
29 CIEEM (2018). Guidelines for Ecological Impact Assessment in the UK and Ireland: Terrestrial, Freshwater, Coastal and Marine. Version 1.1. Available: https://cieem.net/wp-content/uploads/2018/08/ECIA-Guidelines-2018-Terrestrial-Freshwater-Coastal-and-Marine-V1.1.pdf [Accessed June 2020] 7-1 The EZoI for sites designated for nature conservation importance and their qualifying interests has also been considered. In the first instance, the following search buffers have been used to identify designated sites; then an assessment of connectivity or functional linkage has been made to identify which designated sites occur within a potential EZoI: · OHL Route plus 1 km – locally and nationally designated sites; protected and priority species and habitats; and · OHL Route plus 10 km – Natura 2000 sites30.
Distinct field survey areas have also been established. These are set out with justifications in the section on Method of Baseline Data Collation. Broadly, habitat and protected species surveys were undertaken across areas of moderate to high ecological sensitivity along the OHL Route based on existing ecological data on nature conservation sites, habitats and species. No dedicated ornithological surveys have been undertaken due to the large extent of the OHL Route and the relevant associated survey area. Breeding bird surveys were carried out along the sections of the OHL Route which pass through Devon Gorge SSSI and Pitkeathly Mires SAC and SSSI in 2010 to inform the Previous ES. Those surveys found that the breeding bird assemblages comprised species which were typical of the associated woodland and moorland habitats with sensitive species being limited to small numbers of Red-listed Birds of Conservation Concern31. Updated breeding bird surveys at these locations were not considered necessary as habitat conditions and associated breeding bird assemblages are considered unlikely to have changed substantially since those original surveys. Instead, likely sensitive ornithological receptors which may be affected by the Proposed Development have been identified along the entire OHL Route through a consultation exercise with ornithological interest groups and land management organisations, details of which are provided below.
Consultation Undertaken to Date Consultation undertaken to date mainly pertains to the EIA Scoping Report. Scoping responses received at the time of writing which are relevant to this chapter are captured in Table 7-1. A separate data request exercise has been undertaken specifically to obtain information relevant to sensitive ornithological receptors across the OHL Route and a surrounding buffer of 2 km, to supplement existing records and in the absence of dedicated bird surveys. A summary is provided in Table 7-1. It was not considered necessary to undertake additional data requests for other biodiversity data because existing data from the Previous ES and earthwire replacement works were available for interpretation in combination with current data from field surveys undertaken from April to June 2020 specifically to inform this EcIA.
Table 7-7-1 Scoping responses and other consultations of relevance to Chapter 7
Organisation Type of Response How response has been Consultation considered Scottish Natural EIA Scoping NatureScot was satisfied with the NatureScot have been consulted via Heritage (SNH) Report; June ecological features identified to be email and phone in June 2020 (now 2020 scoped in and out. NatureScot specifically regarding Pitkeathly NatureScot) welcome close engagement Mires, to obtain existing data regarding European sites, available for the designated site and particularly Pitkeathly Mires Special initial feedback on appropriate Area of Conservation, to ensure mitigations; fully detailed alongside
30 Natura 2000 is a network of sites across the European Union designated for rare and threatened species, and rare natural habitat types, protected under the Birds Directive 2009/147/EC and the Habitats Directive 92/43/EEC. 31 Eaton MA, Aebischer NJ, Brown AF, Hearn RD, Lock L, Musgrove AJ, Noble DG, Stroud DA and Gregory RD (2015). Birds of Conservation Concern 4: the population status of birds in the United Kingdom, Channel Islands and Isle of Man. British Birds 108, 708–746. 7-2 Organisation Type of Response How response has been Consultation considered sufficient information is provided at sufficient information to inform the the application stage to inform a HRA in Appendix 7.3: Pitkeathly Habitats Regulations Appraisal Mires SAC National Vegetation (HRA) process. Classification Survey Report. Tower With regards to the River Dee and Pre-construction surveys will Extension River Tay SACs, NatureScot include locations of temporary Consultation; acknowledged that the precise masts which will be micro-sited August 2020 locations of the temporary masts and/or appropriate mitigation were not yet determined but that measures applied as necessary. ecological interests and sensitivities would be identified and afforded adequate protection, and micro siting used to avoid sensitive areas.
Regarding guyed temporary masts, NatureScot advised that if these were to be located in sensitive ornithological locations where greater in-flight bird movements might be anticipated then guy lines should marked with bird deflectors to minimise collision risk and referred to their relevant guidance. Additional Providing the EIAR captures the Consideration of how the additional Tower various protected areas and assess tower extensions and their Extension the effects and proposes mitigation associated temporary diverstions Consultation; (if required), this should be may affect protected sites and October sufficient information to support other features of ecological interest 2020 the application and the proposed (i.e. sensitive habitats and protected methodology should be species) has been considered in this appropriate. EIA Report and pre-construction surveys and/or appropriate mitigation measures will be applied as necessary. Scottish EIA Scoping SEPA was satisfied with the Access routes and felling Environment Report; June ecological features identified to be requirements have been included in Protection 2020 scoped in and out. SEPA expect all the assessment. The locations of Agency (SEPA) associated works required to temporary site compounds and facilitate the Proposed temporary infrastructure remains Development (including vegetation broadly unknown, therefore this clearance, access track upgrades, chapter assumes that these will temporary site compounds, water avoid direct effects to IEFs through crossings) to be outlined and micro-siting, and embedded and mitigations detailed in the EIA industry-standard mitigation Report. measures would reduce potential indirect effects. Aberdeenshire EIA Scoping Designations and designated sites Local authority boundaries have Council Report; June should have their associated local been included on Figure 7.1: 2020 authority clearly marked within the Designated Sites. EIA Report to aid with assessment of the eventual submission. Marine Scotland EIA Scoping The OHL Route crosses or extends This chapter has considered Report; June adjacent to watercourses which potential impacts to the following 2020 support important salmon and trout as distinct IEFs: River Dee SAC, River populations; three of which are South Esk SAC and River Tay SAC; River Dee SAC, River South Esk SAC running water as a habitat type; and and River Tay SAC with salmon fish. being a qualifying feature. The Applicant should detail appropriate site specific mitigation measures in the EIA Report to avoid / minimise
7-3 Organisation Type of Response How response has been Consultation considered impacts on water quality and fish populations of all watercourses which could potentially be impacted, as well as proposed monitoring programmes if required. Dee District EIA Scoping Dee DSFB do not anticipate a GEMPs cover the topics of concern Salmon Fishery Report; June significant impact upon water to Dee DSFB. A CEMP and ECoW Board (DSFB) 2020 quality and fish habitat of the Dee will support the construction phase. District. However they Dee DSFB contact information will acknowledge there are risks which be included within the CEMP and should be considered and mitigated the ECoW will liaise with Dee DSFB for through a Construction as required. Environmental Management Plan (CEMP) or General Environmental Management Plans (GEMPs). Areas of concern would relate to watercourse crossings; working in or near surface waters; soil removal; storage and reinstatement; oil and fuel storage and refuelling; adverse weather conditions. Dee DSFB anticipate GEMPs would cover these topics. Dee DSFB also support provision of an Environmental Clerk of Works (ECoW) and wish to liaise with the ECoW throughout the construction phase, potentially visit the site, and be included in regular communications to offer support, guidance and raise concerns. Fossoway EIA Scoping It was agreed to scope out Gartwhinzean Meadow SSSI has Community Report; June Gartwhinzean Meadow SSSI from been scoped out; Devon Gorge has Council 2020 the EIA as it is too far from the OHL been scoped in. Tree felling Route to be affected. Devon Gorge impacts on Devon Gorge SSSI have SSSI should be scoped in; the been addressed in this Chapter and Community Council raised also Volume 4 Appendix 3.1: concerns about tree felling in this Forestry. area and wish to be kept aware of such plans. Royal Society EIA Scoping RSPB did not have any concerns on Data has been requested from for the Report; June the scope of the EIA. The RSPB, North East Scotland Raptor Protection of 2020 distribution and presence of species Study Group, Tayside and Fife Birds (RSPB) will have changed since the Raptor Study Group, Central Previous ES, so increasing the Scotland Raptor Study Group, and number of organisations consulted Forestry and Land Scotland (see for data would be appropriate. below). Additional contacts have Based on the data derived from the not been approached as consultation exercise, it may be ornithological data supplied has necessary to revise the scope. In been considered sufficient to addition to Raptor Study Groups support the assessment. and Forestry and Land Scotland, RSPB recommend contacting: Scottish Wildlife Trust – Loch of Lintrathen; local bird recorders – Angus, Perth and Kinross, and North East Scotland; and North East Scotland Biological Records Centre (NESBReC). RSPB Data request RSPB provided records of rare and Data provided by RSPB is presented via letter; vulnerable raptor nest sites within in Appendix 7.4: Bird Consultation May 2020 Results and Appendix 7.5:
7-4 Organisation Type of Response How response has been Consultation considered the 2 km search area along the OHL Confidential Bird Records and has Route. been used to inform the assessment of potential impacts on ornithological receptors in this EcIA. North East Data request NESRSG provided records of rare Data provided by NESRSG is Scotland Raptor via letter; and vulnerable raptor nest sites presented in the Appendix 7.5: Study Group May 2020 within the 2 km search area along Confidential Bird Records and has (NESRSG) the OHL Route. been used to inform the assessment of potential impacts on ornithological receptors in this EcIA. Tayside and Fife Data request T&FRSG provided records of rare Data provided by T&FRSG is Raptor Study via letter; and vulnerable raptor nest sites presented in Appendix 7.5: Group (T&FRSG) May 2020 within the 2 km search area along Confidential Bird Records and has the OHL Route. been used to inform the assessment of potential impacts on ornithological receptors in this EcIA. Central Scotland Data request CSRSG provided records of rare and Data provided by CSRSG is Raptor Study via letter; vulnerable raptor nest sites within presented in Appendix 7.5: Group (CSRSG) May 2020 the 2 km search area along the OHL Confidential Bird Records and has Route. been used to inform the assessment of potential impacts on ornithological receptors in this EcIA. Forestry and Data request FLS provided records of rare and Data provided by FLS is presented in Land Scotland via letter; vulnerable raptor nest sites from Appendix 7.5: Confidential Bird (FLS) May 2020 their land holdings within the 2 km Records and has been used to search area along the OHL Route. inform the assessment of potential impacts on ornithological receptors in this EcIA.
Method of Baseline Data Collation Desk Study A review of existing ecological and ornithological data gathered to support the Previous ES and the earthwire replacement works has been undertaken. The following online resources have also been reviewed to identify sites and habitats designated for nature conservation importance at the local, national and European level. · NatureScot Site Link32; · Improvement Service (IS) Spatial Hub: Source of Scottish Local Government Spatial Data33; and · Scottish Forestry Map Viewer34.
A desk-based assessment of suitable bat roosting habitat has been undertaken, categorising woodlands within 50 m either side of the OHL Route as being of high, moderate or low roost suitability using predefined criteria set out in Appendix 7.1: Extended Phase 1 Habitat Survey and Protected Species Survey Report. This assessment has incorporated extended Phase 1 habitat survey data and target notes relating to woodlands and bats where available from the field surveys (see Field Survey below). This review has been based on professional experience, precautionary assumptions, and guidance resources including from Bat Tree Habitat Key35 and Bat Conservation Trust36; the findings have been reviewed by an ecologist who holds a NatureScot bat roost survey licence.
32 Available: https://sitelink.nature.scot/home [Accessed March 2020] 33 Available: https://www.spatialhub.scot/ [Accessed March 2020] 34 Available: https://forestry.gov.scot/support-regulations/scottish-forestry-map-viewer [Accessed June 2020] 35 Bat Tree Habitat Key (2019). Bat Roosts in Trees: A guide to identification and assessment for tree-care and ecology professionals. Pelagic Publishing. 36 Collins, J. (ed.) (2016). Bat Surveys for Professional Ecologists: Good Practice Guidelines (3rd edn). Bat Conservation Trust, London. 7-5 Ornithological records identified from the Previous ES and earthwire replacement works were supplemented by requests for data from other organisations and study groups as summarised in Table 7-7-1 above and fully detailed in Appendix 7.4: Bird Consultation Results and Appendix 7.5: Confidential Bird Data.
Field Survey All field surveys were undertaken by a team of six competent ecologists who hold current CIEEM membership and sufficient experience of surveying for habitats and protected species likely to be encountered across the prevailing landscape. All data were captured electronically using tablets. A proportionate field survey approach was designed to capture current data from locations of relatively moderate to high ecological sensitivity along the 168 km OHL Route. An ecological sensitivity level (low, moderate or high) was assigned to each tower along the OHL Route (total no. 529 towers; Towers 34 to 559R). The ecological sensitivity level of each tower is colour coded as represented in Figures 7.1.1 and 7.1.2 of Appendix 7.1: Extended Phase 1 Habitat and Protected Species Survey Report and Figure 7.2.1 of Appendix 7.2: Confidential Badger Data: low-yellow; moderate-orange and high-red. The ecological sensitivity levels were determined using existing ecological data on nature conservation sites, habitats and species gleaned from the Desk Study; supplemented by professional experience of the prevailing landscape and satellite imagery. This approach was designed to focus field survey effort on areas of moderate to high ecological sensitivity; covering approximately 50% of the OHL Route. This approach is proportionate to the scale and type of the Proposed Development (with infrastructure already in place) and expands upon existing data and assessments used to support relatively recent and similar works associated with the earthwire replacement works. It has also been essential to design a targeted survey approach to maintain the programme of the Proposed Development through fieldwork challenges associated with the COVID- 19 pandemic. The following surveys were undertaken between April and June 2020: · Extended Phase 1 habitat survey following industry standard practice from Joint Nature Conservation Committee37 (JNCC), mapping habitats and the suitability of features to support protected species up to 50 m from towers and interconnecting conductors between successive towers of moderate to high ecological sensitivity along the OHL Route; · Target noting of sensitive habitats which should be avoided (e.g. heath, bog, flush, fen) within 50 m of access tracks associated with towers of moderate to high ecological sensitivity (though no habitat mapping was undertaken along access tracks); · Badger survey for signs of activity within suitable habitats (e.g. woodland, scrub, field boundaries) broadly following methods outlined by Scottish Badgers38 and standing advice for developers from SNH39, up to 50 m from towers, interconnecting conductors and associated access routes of moderate to high ecological sensitivity along the OHL Route (deviations justified in Table 7- 7-6); · Otter, beaver and water vole suitability surveys of watercourses which cross the OHL Route and access routes associated with towers of moderate to high ecological sensitivity; signs of species activity were recorded incidentally keeping a 2 m distance from the waters’ edge; up to 50 m up
37 JNCC (2010). Handbook for Phase 1 habitat survey – a technique for environmental audit. Joint Nature Conservation Committee, Peterborough. 38 Scottish Badgers (2018). Surveying for Badgers. Good Practice Guidelines (V1). Available: https://scottishbadgers.org.uk/userfiles/file/planning_guidelines/Surveying-for-Badgers-Good-Practice-Guidelines_V1.pdf [Accessed March 2020] 39 Scottish Natural Heritage (2019). Standing advice for planning consultants: Badger. Available: https://www.nature.scot/sites/default/files/2020- 06/Species%20Planning%20Advice%20-%20badger.pdf [Accessed March 2020]
7-6 and downstream, with reference to SNH’s relevant protected species advice for developers40 (deviations justified in Table 7-7-6); · Target noting of habitat or features used by other protected/notable fauna within 50 m of access tracks associated with towers of moderate to high ecological sensitivity; and · National Vegetation Classification (NVC) survey following industry recognised practice41 up to 100 m from the OHL Route and access routes which extend through Pitkeathly Mires SAC and SSSI.
Full methods of the field surveys are detailed in Appendix 7.1: Extended Phase 1 Habitat Survey and Protected Species Survey Report and Appendix 7.3: Pitkeathly Mires National Vegetation Classification Survey Report.
Assessment Modelling The assessment focuses on receptors of greatest nature conservation value (IEF), as supported by CIEEM EcIA Guidelines. To inform the scoping of relevant IEFs, each has been evaluated in line with the criteria presented in Table 7-7-2. For the purposes of this assessment, ornithological receptors were evaluated and assessed as part of either the breeding or wintering bird assemblage present within the EZoI. This approach is suitable due to the commonality of impacts from the Proposed Development on different species and species groups. Bird species designated as qualifying species of Natura 2000 sites assessed in this report are not subsequently considered in the Breeding or Wintering bird receptors.
For the purposes of this assessment, the nature conservation values are interpreted as follows: International = Europe, National = United Kingdom, Regional = Scotland, County = Aberdeenshire / Tayside / Perth and Kinross, and Local = cities, towns, villages within the counties.
Table 7-7-2 Ecological value criteria42
Nature Criteria/ examples conservation value
International A site designated under international conventions or European directives meeting the criteria for Natura 2000 sites, or a Ramsar site. Considerable extents of a priority habitat type listed in Annex I of the Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora, or smaller area of such habitat that are essential to maintain the viability of a larger area. Any regularly occurring population of an internationally important species, which is threatened or rare in the UK, i.e. a IUCN ’Red List’ species, or any species of uncertain conservation status or of global conservation concern. A regularly occurring significant population/ number of any internationally important species i.e. European Protected Species.
National Nationally designated sites, or sites meeting the criteria for national designation. Notified species/habitats of a nationally designated site. A nationally important, viable area of priority habitat identified within the Scottish Biodiversity List (SBL), or a smaller area which is vital for the viability of a larger area. A regularly occurring significant population/ number of any nationally important species i.e. listed on the Wildlife and Countryside Act (1981) (as amended). Species present in nationally important numbers (>1 % UK population).
40 Scottish Natural Heritage (2019). Planning and development protected species. Available: https://www.nature.scot/professional-advice/planning-and- development/planning-and-development-advice/planning-and-development-protected-species [Accessed March 2020] 41 Rodwell, J. S. (2006). NVC Users’ Handbook. JNCC, Peterborough. 42 Hill, D., Fasham, M., Tucker, G., Shewry, M. and Shaw, P. (2005). Handbook of Biodiversity Methods: Survey, Evaluation and Monitoring.
7-7 Nature Criteria/ examples conservation value Any regularly occurring highly significant population of any bird species listed on the ‘Red List’ of Birds of Conservation Concern43 (BoCC).
Regional Any internationally or nationally important habitat (as described above) that is currently degraded but has the potential for restoration. Sites falling slightly below criteria for selection as a national designated site. Regularly occurring moderate to large populations / numbers of SBL species. Species present in regionally important numbers (>1 % of the regional population). Any regularly occurring regionally significant population of ‘Red List’ BoCC.
County A regularly occurring, viable population of an SBL species or habitat which is scarce in the County. County-significant populations of ’Red List’ BoCC.
Local Local Nature Conservation Sites (LNCS) identified by the Local Authority. Viable areas of local priority habitat or small areas of such habitats which are essential to maintain the viability of the larger area; identified by the Local Authority often through a Local Biodiversity Action Plan. Areas identified of conservation interest by organisations such as the Scottish Wildlife Trust. Areas of ancient woodland and native woodland smaller than 0.25 ha. A regularly occurring, substantial population of a species scarce in the local area or of local priority. Locally significant populations of ’Red List’ BoCC. Areas of habitat or species considered to enrich the ecological resource within the local context (e.g. hedgerows).
Site Habitats and species that are of low to no ecological value and enrich the habitat resource at a site level due to their size, extent, species composition and other factors.
Determining Magnitude of Change and Sensitivity of Receptors Impact magnitude refers to changes in the extent and integrity of an ecological receptor. A definition of ecological ‘integrity’ within Scottish Planning Policy is found within Circular 6/1995 (Scottish Executive44) and has also been approved by the European Commission (EC, 2018) in “Managing Natura 2000 Sites”. It states that ‘The ‘integrity of the site’ can be usefully defined as the coherent sum of the site’s ecological structure, function and ecological processes, across its whole area, which enables it to sustain the habitats, complex of habitats and / or populations of species for which the site is designated’. Although this definition is used specifically regarding European designated sites, it is applied here to wider-countryside habitats and species. Detailed consideration of impact magnitude is a standard component of EcIA. It is incorporated to succinctly describe the scale of individual impacts. The magnitude of effects is predicted quantitatively where possible, taking into account the duration and reversibility of effects, and is considered spatially and temporally as described within Table 7-7-3 and Table 7-7-4. Effects can be adverse, neutral or beneficial.
43 Eaton, M. A., Aebischer, N. J., Brown, A. F., Hearn, R.D., Lock, L., Musgrove, A. J., Noble, D. G., Stroud, D.A. and Gregory, R. D. (2015). Birds of Conservation Concern 4: the population status of birds in the United Kingdom, Channel Islands and Isle of Man. British Birds 108: 708-746.
44 Scottish Executive (2000). Nature conservation: implementation in Scotland of EC Directives on the conservation of natural habitats and of wild flora and fauna and the conservation of wild birds (‘The Habitats and Birds Directives’). Revised guidance updating Scottish Office Circular no. 6/1995. 7-8 Table 7-7-3 Description of spatial impact magnitudes (adapted from the CIEEM EcIA Guidelines29)
Spatial impact Description magnitude
High Major effect on the nature conservation status of the Site, habitats or species, likely to threaten the long-term integrity of the system.
Medium Moderate effect on the nature conservation status of the Site, habitats or species, but would not threaten the long-term integrity of the system.
Low Noticeable effects, but either of sufficiently small scale or short duration to cause no harm to the conservation status of the Site, habitats or species.
Negligible Not expected to affect the conservation status of the Site, habitats or species under consideration in any way, therefore no noticeable effects on the ecological resource.
Table 7-7-4 Description of temporal impact magnitudes45
Temporal impact Description magnitude
Permanent Effects continuing indefinitely beyond the span of one human generation (taken as approximately 25 years), except where there is likely to be substantial improvement after this period.
Long-term Approximately 15 - 25 years.
Medium-term Approximately 5 – 15 years.
Short-term Up to approximately 5 years.
The significance level attributed to potential effects has been assessed based on the magnitude of impacts from the Proposed Development and the sensitivity of the affected IEFs or receiving environment to change. Table 7- 7-5 details the significance criteria that have been used in assessing the effects from the Proposed Development.
Table 7-7-5 Significance criteria (adapted from the CIEEM EcIA Guidelines)
Level of Description significance
Major This is a significant effect (either beneficial or adverse), as the effect is likely to result in a long term significant adverse effect on the integrity of the receptor at a particular geographical scale.
Moderate This is a significant effect (either beneficial or adverse), as the effect is likely to result in a medium term or partially significant adverse effect on the integrity of the receptor at a particular geographical scale.
Minor The effect is likely to adversely affect the receptor at an insignificant level by virtue of its limited duration and/or extent, but there will probably be no effect on its integrity. This is not a significant effect.
Negligible No discernible effect is expected as a result of the Proposed Development.
As part of the assessment of ecological impact, magnitude and significance, the degree of confidence in the assessment will be qualitatively described for the ecological assessment, following the CIEEM EcIA Guidelines29. Confidence intervals are defined as: · Certain / Near Certain: probability estimated at 95 % or higher; · Probable: probability estimated at above 50 % but below 95 %; · Unlikely: probability estimated above 5 % but less than 50 %; or
45 Regini, K. (2000). Guidelines for ecological evaluation and impact assessment. Ecology and Environmental Management. In Practice, 29 (September), pp. 1, 3-7. Winchester, Institute of Ecology and Environmental Management. 7-9 · Extremely unlikely: probability estimated at less than 5 %.
Limitations and Assumptions The survey effort was focused around approximately 50 % of the OHL Route; it covered all extents considered to be of moderate to high ecological sensitivity (262 towers). Considering the extent of the OHL Route and the type of works associated with the Proposed Development, in combination with COVID-19 pandemic challenges to fieldwork, it was essential to identify a proportionate approach for data collection which would remain robust and sufficient to inform the EcIA and any necessary mitigation. It was considered suitable to survey up to 50 m from the OHL Route and access routes, given data available from previous studies and the prevailing, agricultural landscape which is typically of low ecological value. Deviations from ecological survey guidance and justifications are set out in Table 7-7-6 for transparency.
Table 7-7-6 Justified deviations from ecological survey guidance
Survey Deviation from guidance Justification
Badger Scottish Badgers (2018) guidance Given the tower infrastructure already exists, the type of recommends surveys extend up works associated with the Proposed Development would to 100 m from proposed works. be unlikely to impact badgers using features beyond 50 m Badger surveys were undertaken of the OHL Route or access routes. There will be no high up to 50 m from the Proposed vibration or highly noisy works. Development. An exception to this would be felling requirements (see Paragraph 7.2.28 below). Otter, SNH guidance recommends otter Given the tower infrastructure already exists, the type of beaver, surveys extend up to 200 m from works associated with the Proposed Development would water vole proposed works; water vole be unlikely to impact otter, beaver or water vole using surveys up to 50 m; and beaver features beyond 50 m of the OHL Route or access routes, surveys up to 250 m. assuming embedded mitigation associated with working These surveys were undertaken in / near watercourses is implemented successfully. There up to 50 m from the Proposed will be no high vibration or highly noisy works. Development. Surveys were undertaken by lone-working surveyors as Surveys were undertaken whilst part of COVID-19 controls and to maintain the programme maintaining a 2 m buffer from the of the Proposed Development, therefore it was essential waters’ edge. for surveyors to maintain a minimum 2 m buffer from the waters’ edge to sufficiently mitigate the risks associated with immersion. Surveyors were equipped with binoculars and recorded opportunities for resting sites on a precautionary basis. An overall suitability level was assigned to each watercourse for each species of interest, depending on factors such as bankside vegetation, connectivity, flow, substrate, etc. which could be easily deduced from the 2 m buffer. Access Access routes were walked to Landowner permissions were restricted to the access routes record features used by badgers, routes and did not extend to adjacent land unless within otters, water vole, beaver or other the same holding as the OHL Route. protected or notable fauna and The majority of access routes extend over existing roads or flora; detailed surveys of habitats tracks. Access routes would be used temporarily and either side of access routes were would not require permanent changes to habitats. The not undertaken. same access routes were used in 2017 for the earthwire replacement works.
7-10 As noted in Chapter 3, Section 3.2, resilience studies are being undertaken to determine the extent of additional tree felling which would be required along the OHL Route (beyond the existing maintenance boundary associated with the 275 kV OHL) to achieve mandatory clearance distances as a result of the proposed voltage upgrade. Volume 4 Appendix 3.1: Forestry identifies areas where individual trees amongst woodlands will require felling in relation to the upgrade of the OHL from 275 kV to 400 kV and three distinct areas where relatively greater woodland clearance (albeit still minor) will be required to create a windfirm edge. This Chapter addresses woodland habitat loss based on the findings of Volume 4 Appendix 3.1: Forestry. The proximity of additional felling from the OHL Route may be as much as 40 m from the centre line. As well as the loss of woodland habitat, this may also pose a risk of disturbance to species associated with woodland (e.g. badgers) beyond the 50 m survey areas set out in Table 7-7-6. There would also be potential for direct impacts to arboreal species such as red squirrel and pine marten within the areas earmarked for felling. To mitigate this limitation, a precautionary approach has been adopted when assessing the impacts of felling, based on all data recorded to date. A desk-based review of bat roost suitability within woodlands along the OHL Route has been undertaken to identify areas with relatively greater risk of negative effects from felling. It should be noted that this assessment only encompasses blocks of woodland mapped during the extended Phase 1 habitat survey. Tree lines or individual scattered trees which have not been mapped due to the mapping scale adopted for the extended Phase 1 habitat survey have not been included in this desk-based suitability assessment. This is a high-level approach intended to inform a precautionary EcIA of felling impacts resulting in the potential loss of roost sites. Ultimately, it is anticipated that dedicated surveys to identify roosts in areas of woodland earmarked for felling would be undertaken prior to felling (as part of planning conditions) and that the loss of any confirmed roosts would be mitigated for through strict European Protected Species licensing and associated tests.
7.3 Baseline Conditions Please refer to the following baseline reports for full details of baseline conditions. A summary of each feature is included when evaluating their relative nature conservation value (see Sensitive Receptors of this Section) or scoping them out from further assessment (see Section 7.4- Issues Scoped Out), as part of the justification behind this. · Appendix 7.1: Extended Phase 1 Habitat and Protected Species Survey Report; · Appendix 7.2: Confidential Badger Data; · Appendix 7.3: Pitkeathly Mires National Vegetation Classification Survey Report; · Appendix 7.4: Bird Consultation Results; and · Appendix 7.5: Confidential Bird Data.
Future Baseline In the absence of the Proposed Development, the habitats identified directly under the OHL and existing wayleave either side of the OHL (the ‘operational corridor’) are likely to continue to be present due to the management regimes and maintenance agreements in place for the operational corridor. Additional felling to maintain a safe operational corridor through woodlands for the upgrade of the OHL from 275 kV to 400 kV will see permanent, localised changes to the habitats in these areas. In the absence of specific enhancement measures or differing management, it is anticipated that the habitats of felled areas would begin to reflect the wider operational corridor over a medium-term period and beyond. For example, where heath occurs between plantation woodland within the current operational corridor, it is likely that the adjacent corridor to be felled will be able to viably shift towards heath. This particular example could result in a biodiversity gain relative to the baseline conditions.
7-11 As outlined in Table 7-7-7, the range and population size of some species is stable or increasing (e.g. otters) and some species appear to be declining (e.g. red squirrel). These trends are predicted to continue in the absence of development.
Sensitive Receptors Aligning with CIEEM EcIA Guidelines but remaining consistent with the wider EIA Report, the terms ‘sensitive receptor’ and ‘IEF’ (see Assessment Modelling of Section 7.2) will be used synonymously throughout this chapter. The habitats and species identified as IEF are presented in Table 7-7-7, together with the justification for this evaluation. An IEF is a sensitive receptor that occurs within the EZoI (see Assessment Modelling of Section 7.2) and which has been evaluated to be of Local nature conservation value or above.
Table 7-7-7 – Nature conservation value of Important Ecological Features scoped-in
Feature Nature Justification conservation value Pitkeathly International The OHL Route extends through this SAC (and SSSI) for approximately 980 m Mires SAC between Towers 105 and 109. and SSSI Pitkeathly Mires is designated for transition mires and quaking bogs, and slender green feather moss. As it is statutorily designated of European importance as a SAC, this site is automatically valued at the International level. Transition mires and quaking bogs at Pitkeathly Mires are listed to be in favourable maintained condition (2003). Whilst this condition assessment is out-dated, the 2019 UK Habitats Directive Report stated that 98 % of SAC designations for transition mires and quaking bogs were in favourable condition (a slight increase of 1 % since the previous report)46 so it is assumed that qualifying habitats there remain in overall favourable condition. Slender green feather-moss at Pitkeathly Mires is also listed to be in favourable maintained condition (2008). Trends for this species are uncertain as there is insufficient data and it is likely greater than 75% of its populations across Scotland are under-recorded because supporting habitat is disperse; large populations were recently discovered on Tiree47. River Dee International This SAC is designated for otter, Atlantic salmon and freshwater pearl mussel. SAC and As it is statutorily designated of European importance as an SAC, this site is LNCS automatically valued at the International level. The OHL Route spans this SAC (and LNCS) between Towers 494 and 495 for approximately 290 m. Volume 4 Appendix 3.1: Forestry advises that a well- maintained operational corridor exists through the lowland mixed deciduous/ wet woodland either side of the River Dee; therefore there is no requirement for woodland clearance for the OHL Route. An extension to Tower 495, which falls within the SAC boundary, will be required; and associated temporary diversion over the SAC. Volume 4 Appendix 3.1: Forestry advises that modest felling (measurable in number of trees, not forest felling area) is possible on the south bank and probable felling is anticipated to extend an existing clearing on the north bank to accommodate a temporary mast. In 2011-12, national surveys commissioned by SNH assessed the condition of SACs designated for otter. River Dee SAC was reported to be in unfavourable condition, reflecting three other SACs in the Dee Catchment49. However, the results of these surveys may have been limited by poor weather and high flows. Overall, the 2019 UK Habitats Directive Report considers that SAC otter populations are stable in the short-term as their range is unchanged and there is unlikely to be a change in the availability and quality of otter habitat47.
46 JNCC (2019). Article 17 Habitats Directive Report 2019: Habitat Conservation Status Assessments. Available: https://jncc.gov.uk/our-work/article-17-habitats- directive-report-2019-habitats/ [Accessed July 2020] 47 JNCC (2019). Article 17 Habitats Directive Report 2019: Species Conservation Status Assessments. Available: https://jncc.gov.uk/our-work/article-17-habitats- directive-report-2019-species/ [Accessed July 2020]
7-12 Feature Nature Justification conservation value SEPA list the stretch of the River Dee spanned by the OHL Route to be in overall moderate condition, and the Burn of Sheeoch (a tributary included under River Dee SAC also crossed by the OHL Route between Towers 488 and 489) to be in good condition48. The River Dee is one of SEPA’s 14 ‘priority catchments’, however issues identified lie mainly in the lower catchment away from the OHL Route. Freshwater pearl mussel was last assessed to be in an unfavourable but not changing condition (2003). Atlantic salmon was last assessed to be in a favourable maintained condition (2011). The LNCS designation is consistent with the SAC, but is a non-statutory designation acknowledging this as an important local biodiversity resource selected by Aberdeenshire Council. River South International This SAC is designated for Atlantic salmon and freshwater pearl mussel; both Esk SAC last assessed to be in an unfavourable condition but with Atlantic salmon considered to be recovering. As it is statutorily designated of European importance as an SAC, this site is automatically valued at the International level. The OHL Route extends in parallel to this SAC between Towers 289 and 297; and crosses it between Towers 289 and 290, 296 and 297, and 312 and 313. Volume 4 Appendix 3.1: Forestry advises that the operational corridor at these locations is narrow but currently vertical separation is maintained between small trees within the corridor and the OHL. The low stature of trees and small coverage therefore represents cleaning rather than felling requirement. SEPA list the stretch of the River South Esk SAC which extends in proximity to the OHL Route to be in overall good condition48. River Tay International This SAC is designated for otter, Atlantic salmon, brook lamprey, and clear- SAC water lakes or lochs with aquatic vegetation and poor-moderate nutrient levels. All of these features were last assessed to be in a favourable maintained condition. As it is statutorily designated of European importance as an SAC, this site is automatically valued at the International level. The OHL Route spans this SAC at 10 distinct locations, between Towers: 147 and 148; 160 and 161; 172 and 173; 201 and 202; 205 and 206; 220 and 221; 224 and 226; 232 and 234; 244 and 245; 266 and 267. Volume 4 Appendix 3.1: Forestry only identified the requirement for felling of individual trees amongst wet woodland at Lunan Burn (near Tower 205), where open grown trees cross with some close to the conductor. Some other individual trees require further assessment as part of the resilience study, however there will be no forestry impact from the upgrade works. An extension to Tower 148 will be required; and an associated temporary diversion over the SAC. Volume 4 Appendix 3.1: Forestry did not identify any felling requirements in relation to this tower extension. The most recent site condition monitoring surveys for SACs designated for otters reported that River Tay SAC was reported to be in favourable condition; evidence of otters was recorded throughout the catchment49. SEPA list the River Tay and its tributaries which comprise the River Tay SAC to be in moderate to good condition48. The Tay Catchment is one of SEPA’s 14 ‘priority catchments’. Devon National This SSSI is notified for upland mixed ash woodland, last assessed to be in an Gorge SSSI unfavourable and declining condition (2009).
48 Available: https://www.sepa.org.uk/data-visualisation/water-classification-hub/ [Accessed July 2020] 49 Findlay, M., Alexander, L. and Macleod, C. (2015). Site condition monitoring for otters (Lutra lutra) in 2011-12. Scottish Natural Heritage Commissioned Report No. 521. Available: https://www.nature.scot/snh-commissioned-report-521-site-condition-monitoring-otters-lutra-lutra-2011-12 [Accessed July 2020]
7-13 Feature Nature Justification conservation value A field survey undertaken to inform Volume 4 Appendix 3.1: Forestry identified that ash dieback is extensive and invasive sycamore will alter the SSSI’s characteristics as an ash woodland. The OHL Route traverses this SSSI between Towers 40 and 44. The main SSSI woodland extends over a deep gorge with steep sides. Volume 4 Appendix 3.1: Forestry advises that no trees within the steep gorge sides require felling where the OHL Route traverses the gorge. At the head of the slopes, distances to individual field boundary trees will be assessed for resilience as part of future studies, but no additional woodland clearance is anticipated. As it is statutorily designated as a SSSI, this site is automatically valued at the National level. Gannochy National This SSSI is notified for beetles and a lichen assemblage which were both last Gorge SSSI assessed to be in an unfavourable declining condition (2004 and 2009, respectively). It is also notified for a bryophyte assemblage assessed to be in a favourable and recovered condition (2012); as well as non-marine Devonian earth science interests. The OHL Route extends immediately north of this SSSI, between Towers 373 and 374. Whilst outwith the SSSI boundary, the woodland along the existing operational corridor is connected to the SSSI. As it is statutorily designated as a SSSI, this site is automatically valued at the National level. Hare Myre, National This SSSI is notified for its important population of overwintering greylag Monk Myre geese. and As this SSSI is located 0.17 km from the OHL Route there is potential for the Stormont Proposed Development to cause disturbance to roosting overwintering Loch SSSI greylag geese. Disturbance to foraging birds using fields in close proximity to the OHL Route is less of a concern as there is an abundance of suitable (agricultural) foraging habitat along the OHL Route to which any disturbed birds can be displaced.
As it is statutorily designated as a SSSI, this site is automatically valued at the National level.
Candyglirach Local This site is not statutorily designated, but has been valued at the Local level LNCS owing to the botanical and invertebrate interests for which it has been selected by Aberdeenshire Council. The OHL Route spans this LNCS between Towers 510 and 513, for approximately 600 m. These woodlands are managed as a recreational paintball grounds. Open habitats within existing operational corridor of the OHL Route through this LNCS are dominated by dry heath with some instances of blanket bog. Loch of Park Local This site is not statutorily designated, but has been valued at the Local level LNCS owing to the botanical and aquatic interests for which it has been selected by Aberdeenshire Council. The OHL Route spans this LNCS between Towers 501 and 510, for approximately 2.7 km. This woodland is predominantly coniferous plantation and was recorded to support protected species including badger and pine marten. Otter signs were recorded along Bo Burn. Open areas are dominated by marshy grassland; sections of heath also occur. Strathifinella Local This site is not statutorily designated, but has been valued at the Local level LNCS owing to the botanical, aquatic and geological interests for which it has been selected by Aberdeenshire Council. The OHL Route spans this LNCS between Towers 404 and 424, for approximately 5.8 km. Woodland either side of the OHL Route through this LNCS is listed as Plantation on Ancient Woodland Sites (PAWS); therefore it is unlikely to be
7-14 Feature Nature Justification conservation value native but has been long-established. This area is also part of actively managed commercial forestry. Wet heath dominates the existing operational corridor through coniferous plantation. Open areas in the south-east of the LNCS boundary predominantly comprise semi-improved grassland with scattered scrub; and a mosaic of wet heath and acid grassland in parts. Running County The OHL Route spans 13 key river catchments: River Don; River Dee water (Grampian); Kincardine and Angus Coastal; Bervie Water; River North Esk (excluding (Tayside); River South Esk (Tayside); River Tay; Perth Coastal; River Earn; Earn River Tay Coastal; River Leven (Fife); and River Devon. SAC, River Rivers are included on the SBL. South Eask The conditions of watercourses along the OHL Route appear generally SAC, River moderate or good but this does vary from bad to high with some Dee SAC) watercourses in the north beyond the River Dee considered to be in poor condition48. This feature has been assessed to be of County level importance, because of the intrinsic connectivity through the various catchments and resource it provides to protected and notable species across the OHL Route; and with reference to their ranging but generally moderate to good conditions. Ancient County Approximately 284 hectares (ha) of woodland within 40 m either side of the Woodland OHL Route is listed on the Ancient Woodland Inventory (AWI) – including areas of Ancient Semi-Natural Woodland (ASNW) and discrete Plantation on Ancient Woodland Sites (PAWS). In Scotland, ASNW is considered to be currently wooded and has been continuously wooded since at least 1750. ASNW is recognised as an irreplaceable habitat and assumed to comprise a diverse structure and species-rich flora having been long-established50. PAWS is long-established, but often non-native. In the absence of site- specific habitat condition data, it has been precautionarily assumed that all woodlands along the OHL Route listed on the AWI are of good condition, high distinctiveness and cannot be recreated. AWI woodlands regularly occur along the OHL Route where woodland cover is relatively scarce across the wider Aberdeenshire, Tayside and Perth and Kinross landscape; thus these woodlands are considered to be of County level importance. Non- Local Scotland comprises approximately 19% woodland cover; with under a quarter designated of these woodlands considered native51. The SBL includes a few terrestrial broadleaved woodland habitats, including lowland mixed deciduous woodland, wet and mixed woodland, and upland birchwoods. native Woodlands are particularly sparse on the east coast and towards the north- woodland east, largely being replaced by agriculture. These woodlands are regularly habitats occurring along the OHL Route where woodland cover is relatively scarce across the wider agricultural landscape. All broadleaved and mixed woodlands play an important role in the ecosystem, offering shelter and foraging opportunities for a wide range of protected and notable species, including specialists and generalists. However, woodlands included in this category may range from immature to mature and have not been included on the AWI. As such, these woodlands are considered to be of Local level importance. Heath Local Wet and dry heath habitats occur across a relatively low proportion of the habitats (wet OHL Route and are therefore assessed to be of Local level importance. and dry Upland heathland is a SBL terrestrial habitat. heaths, One distinct area of continuous heathland occurs between Towers 467 and mosaics with 473. Dry heath with heather and bilberry dominates sloping ground; some acid areas of wet heath occur and there are very localised areas of bog. grassland;
50 SNH (2011). A guide to understanding the Scottish Ancient Woodland Inventory. Available: https://www.nature.scot/guide-understanding-scottish-ancient- woodland-inventory-awi [Accessed July 2020] 51 Walton, P., Eaton, M., Stanbury, A., Hayhow, D., Brand, A., Brooks, S., Collins, S., Duncan, C., Dundas, C., Foster, S., Hawley, J., Kinninmonth, A., Leatham, S., Nagy- Vizitiu, A., Whyte, A., Williams, S., and Wormald, K. (2019). The State of Nature Scotland 2019. The State of Nature Partnership. 7-15 Feature Nature Justification conservation value excluding Another area of intact dry heath occurs on sloping ground by Clune Hill, in those within the centre of the OHL Route at Towers 277 and 278. designated Another area of dry heath extends along sloping hillside and through sites) coniferous plantation in the far north of the OHL Route between Towers 518 and 520. A mosaic of wet heath and acid grassland, with marshy grassland, is present between Towers 333 and 334 located in a steep valley. Heath also occurs within the existing operational corridor along stretches through woodland in the northern half of the OHL Route, where the topography and aspects have allowed for heath to establish in areas of previously felled woodland. Wet heath dominates for long spans within Fetteresso Forest between Towers 454 and 463; and Durris Forest between Towers 473 and 486. Badger Local Badgers and their setts are protected under the Protection of Badgers Act 1992 as amended by the Wildlife and Natural Environment (Scotland) Act 2011. Badgers are not included on the SBL; their level of legal protection has been derived from their persecution. Evidence of badger was regularly recorded along the OHL Route. Seven distinct (likely) main setts, four annex setts, two subsidiary setts and 14 outlier setts (of varying levels of activity), were recorded. A total of 18 latrines (most with very fresh dung) have been identified. Of the main setts identified, the sizes varied with the largest comprising 20-25 entrances. These setts and latrines likely constitute multiple territories. One badger sett has been identified within 30 m of a tower base; a well-used outlier sett (ref. BD-21). Four other setts were identified between 30-50 m from tower bases (refs. BD-10, BD-11, BD-13 and BD-29). Sett BD-29 is a well-used annex sett located directly below the OHL, but approximately 44 m from the nearest tower base. Seven distinct badger setts have been identified within 30 m of access routes, including a likely main sett with ten well-used entrances as close as 2 m from the access route (ref. BD-55). Tower locations remain confidential; see Appendix 7.2: Confidential Badger Data. Badgers are well-adapted to the agricultural landscape which dominates the OHL Route, exploiting and enriching habitats considered to be of negligible to low ecological value in isolation; as well as being associated woodland and riparian habitats. The Mammal Society52 reported that badger populations across the UK have shown an increase, predicted to remain stable; their range has been and is predicted to remain stable. This species is considered to be of Local level importance in the context of the scale of the OHL Route and numerous territories within which it extends. Otter Local Otter is classified as a European Protected Species (EPS) under the (excluding as Conservation (Natural Habitats, &c.) Regulations 1994 (as amended). Otter is a qualifying also an SBL species. interest of Since the 1990s, otters have been considered widespread throughout River Dee Scotland. The most recently reported national survey results (2011-12) SAC and recorded otter presence at approximately 80% of sampled sites (which River Tay included all 44 SAC designated for otter in Scotland and other random sites SAC) across the countryside); this is slightly decreased since the previous national survey in 2003-04 but could be due to factors affecting detectability such as weather53. The Mammal Society52 also reports an increase in the geographical range and population size of otter, predicted to continue increasing. Approximately 11 % of watercourses surveyed along the OHL Route were recorded as optimal for otters; 61 % were recorded as sub-optimal. Otter
52 Mathews, F., Kubasiewicz, L. M., Gurnell, J., Harrower, C. A., McDonald, R. A., Shore, R. F. (2018). A Review of the Population and Conservation Status of British Mammals: Technical Summary. A report by the Mammal Society under contract to Natural England, Natural Resources Wales and Scottish Natural Heritage. Natural England, Peterborough. 53 SNH (2015). Trend Note 23: Tends of Otters in Scotland. Available: https://www.nature.scot/trend-notes-otters-scotland [Accessed July 2020] 7-16 Feature Nature Justification conservation value evidence was regularly recorded along non-designated rivers, burns and drains. During the extended Phase 1 habitat and protected species surveys, one holt was identified; located on the River Earn approximately 50 m from Tower 124. Eight temporary lay-ups (couches) were identified; none within 50 m of towers. Four sprainting sites were recorded where multiple spraints were present of mixed ages, indicating regular presence; and single spraints were recorded throughout. This species is considered to be of Local level importance; it is not scarce across the counties but afforded greater consideration as an EPS. Internationally important populations of otters associated with River Dee SAC and River Tay SAC and addressed as component parts of these SACs. Beaver Local This species has been reintroduced to Scotland and established populations received EPS status in May 2019, with full protection under the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended); populations are allowed to naturally expand only. A beaver population has now established within catchments radiating from the River Tay. Evidence has been recorded where the OHL Route spans River Tay and River Isla. Approximately 2 % of watercourses surveyed along the OHL Route were recorded as optimal for beavers; 9 % were recorded as sub- optimal. The remaining 89 % were considered to be of negligible suitability (due to a combination of geographical range and characteristics of the water feature). Seven burrows were recorded (including those confirmed and those with potential as viewed from the opposite bankside or at a safe distance). No burrows were identified within 50 m of towers as the towers are set back from the banksides. However, there are burrows under the sections spanning the River Tay between Towers 160 and 161; and spanning the River Isla between Towers 220 and 221. No signs of beaver were recorded along the River South Esk or its tributaries, reflecting findings from surveys of the Tayside beaver population in 2017-18; but suitable habitat and connectivity will likely change this in the future54. Whilst reintroduced populations are concentrated around the Tay and Earn catchments and therefore could be viewed as regionally important, there is a high potential for populations to continue expanding where interconnectivity and suitable vegetation are available, and even beyond where ’unsuitable’ habitats occur as dispersing individuals adapt54. The Mammal Society52 also reported that there has been an increase in the population size of beaver. This species is therefore valued at Local level. Bats Local All ten bat species found in Scotland are classified as EPS under the (common Conservation (Natural Habitats, &c.) Regulations 1994 (as amended). Five pipistrelle, species are common and widespread: common pipistrelle, soprano soprano pipistrelle, brown long-eared, Daubenton’s and Natterer’s bat. The remaining pipistrelle, five species have a restricted range: Nathusius’ pipistrelle, Whiskered, noctule, Nathusius’ Brandt’s and Leisler’s bat (the latter two species are less likely to occur along pipistrelle, the OHL Route based on known distributions). All species (except Leisler’s brown long- bat) are listed on the SBL. eared, The National Bat Monitoring Programme Annual Report 201955 presented noctule, field survey data for common pipistrelle and soprano pipistrelle that indicates Daubenton’s, either a steady or significant increase (respectively) since 1999. Roost counts Natterer’s, for both species appeared to have significantly declined since 1999; however Whiskered) it is likely that roosts have been under-recorded and that there may be a tendency for volunteer observers to cease monitoring a roost after an
54 Campbell-Palmer, R., Puttock, A., Graham, H., Wilson, K., Schwab, G., Gaywood, M. J. and Brazier, R. E. (2018). Survey of the Tayside area beaver population 2017- 2018. Scottish Natural Heritage Commissioned Report No. 1013. Available: https://www.nature.scot/snh-research-report-1013-survey-tayside-area-beaver- population-2017-2018 [Accessed July 2020] 55 Bat Conservation Trust (2020). National Bat Monitoring Programme Annual Report 2019. Bat Conservation Trust, London. Available: https://www.bats.org.uk/our- work/national-bat-monitoring-programme/reports/nbmp-annual-report [Accessed July 2020]
7-17 Feature Nature Justification conservation value apparent absence has been recorded, but this incidental negative result may be due to roost switching/low roost site fidelity rather than roost abandonment. Myotis species (e.g. Daubenton’s and Natterer’s bats) and brown-long eared bats are known to constantly switch roost sites throughout the year, even during the maternity season56,57. Roost switching in these species occurs between every one to five days (dependant on species and time of the year) during the active season. It is considered that certain species, particularly those with an affinity for woodland, use a network of different roost sites; and that detection of all tree roosts would require significant survey effort58. For other bat species in Scotland for which trend data were available, stable trends have been reported for roost counts (brown long-eared bat), hibernation sites (Natterer’s bat, Daubenton’s bat) and field activity (Daubenton’s bat)51. The population sizes of all Scottish bat species were reported as uncertain by the Mammal Society due to data deficiency52. Bats are anticipated to occur regularly across all areas of the OHL Route, with different habitats and features likely to support a range of Scottish species. Woodlands along the OHL Route are likely to be used by foraging bats and woodland edges present sheltered commuting routes throughout the wider landscape. Boundary features, such as tree lines or hedgerows or dense scrub along fence lines and dry-stone walls, are also likely to act as navigational aids to commuting bats. Riparian habitats are likely to have relatively high levels of foraging and commuting bat activity. Woodlands along the OHL Route vary in their suitability for roosting habitat. Approximately 10 % of woodlands reviewed (as a desk-based exercise) are considered to be of high bat roost suitability; 30 % offer moderate suitability; and 60 % offer low roost suitability. As a precaution, woodlands have not been assessed as any less than low suitability; but in reality it is likely that much of the 60 % low suitability woodlands are of negligible suitability. Bats are likely to be common and widespread along the OHL Route, adding to the value of all habitats and features to some extent. Bats are considered to be of Local level importance in the context of the scale of the OHL Route. Fish (Atlantic Local Migratory salmonids, their spawn and downstream migrating ‘smolts’ are salmon, afforded protection under the Salmon and Freshwater Fisheries brown and (Consolidation) (Scotland) (Act 2003). Atlantic salmon and river lamprey are sea trout, listed on Schedule 3 of the Conservation (Natural Habitats, &c.) Regulations lamprey, 1994 (as amended). European Watercourses are numerous along the OHL Route, with varying eel; characteristics. Precautionarily, it is assumed that potential exists for fish excluding species of conservation interest to occur and that safe passage for fish exists designation along all watercourses crossed by the OHL Route. under River Fish are considered to be of Local level importance in the context of the scale Dee SAC, of the OHL Route. River Tay SAC or River South Esk SAC) Water vole Local This species only receives partial protection59 under Schedule 5 of the Wildlife and Countryside Act 1981 (as amended); and is also an SBL species. No definitive evidence of water vole was recorded during field surveys (likely due to surveyor safety requirements to maintain a 2 m buffer from the waters’ edge when lone working). Approximately 10 % of watercourses surveyed along the OHL Route were recorded as optimal for water vole; 46 % were recorded as sub-optimal; the remaining 44 % were recorded to be of negligible suitability.
56 Dietz, C, Helversen, O. and Dietmar N. (2011). Bats of Britain, Europe and Northwest Africa. London: A & C Black. 57 Fuhrmann, M. and Seitz, A. (1992). Nocturnal activity of the brown long-eared bat (Plecotus auritus L. 1758): data from radio-tracking in Lenneburg Forest near Mainz (Germany). In: I. Priede and S. Swift (eds), Wildlife Telemetry: Remote Monitoring and Tracking of Animals. Chichester: Ellis Horwood. 58 Andrews, H. (2018). Bat Roosts in Trees: A Guide to Identification and Assessment for Tree-Care and Ecology Professionals. 59 Protection against damage and destruction of burrows and disturbance of individuals whilst using burrows. 7-18 Feature Nature Justification conservation value The Mammal Society52 reported an increase in the population size of water vole in Scotland, but a recent decline in their range. Across the UK, populations are predicted to decline whilst the species’ range may remain stable. This species is valued at a Local level as a precaution, reflecting the increase in population size in Scotland and their overall range is likely to remain stable, as well as being cognisant that the species would enrich the biodiversity value where populations may occur on site. Pine marten County This species receives full protection under Schedule 5 of the Wildlife and Countryside Act 1981 (as amended); and certain methods of killing or taking pine martens are illegal under the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended). Pine marten is also a SBL species. The majority of the OHL Route falls within the known distribution range of pine marten within Scotland60,61. Optimal habitats along the OHL Route for pine marten includes woodlands, including conifer plantations. Evidence of pine marten was recorded in the northern extent of the OHL Route (Aberdeenshire), concentrated along existing rides through coniferous plantation. Particular areas with activity (scats) include through Strathfinella LNCS, Fetteresso Forest, Durris Forest, and Loch of Park LNCS. The Mammal Society52 reported that there has been an increase in the geographical range and population size of pine marten; a continuous expansion in Scotland over the last 20 years, predicted to continue increasing. This species is valued at a County level, enriching the biodiversity resource where territories occur through woodlands in the northern Aberdeenshire areas at the aforementioned woodlands; but likely to occur less frequently across the remainder of the OHL Route. Red squirrel County Red squirrels and their dreys (resting places) receive full protection under Schedules 5 and 6 of the Wildlife and Countryside Act 1981 (as amended). Red squirrel is also an SBL species. Rare sightings of red squirrels were recorded in areas of woodland surveyed along the OHL Route; one sighting within mixed woodland in the far south of the OHL Route near Tower 37, and within mixed woodland in the centre of the OHL Route near Tower 318. The OHL Route does not extend through any areas listed by Forestry Commission Scotland as red squirrel strong-holds or priority woodlands. The Mammal Society52 reported that red squirrel population sizes remain stable in Scotland; but that the distribution has declined since 1995 and may continue to decline. This species has been valued at a County level. The sparse distribution of this species is considered to enhance its conservation value at localised areas where populations may occur; and populations may be scarce along the remainder of the OHL Route with 60 % of woodland assumed to be dense coniferous plantation (as inferred by the bat roost suitability assessment). Red squirrels favour areas of mixed woodland. Rare and County These species all receive special protection being listed on Schedule 1 of the vulnerable Wildlife and Countryside Act 1981 (as amended), while red kite are further breeding protected under Schedule 1A meaning it is an offence to harass them at any raptors: time; largely relating to the harassment of birds at communal roost sites. osprey, Osprey, red kite, and peregrine are also listed on Annex I of the EU Birds marsh Directive, and are so recognised as being rare and vulnerable species of harrier, red conservation concern at a European level. kite, Records received through consultation have confirmed that these species goshawk, occur at variable frequency along the OHL Route and that breeding territories peregrine are held where suitable habitat exists. and barn owl The frequency and distribution at which these species occur along the OHL Route is considered to be representative of their broader geographic
60 Croose, E., Birks, J.D.S., Schofield, H.W. and O’Reill, C. (2014). Distribution of the pine marten (Martes martes) in southern Scotland in 2013. Scottish Natural Heritage Commissioned Report No. 740. 61 The Vincent Wildlife Trust (2020). The Pine Marten. Available: [https://www.vwt.org.uk/species/pine-marten/]. [Accessed June 2020]. 7-19 Feature Nature Justification conservation value distribution at the Regional (Scottish) level. These species are therefore valued at a County level reflecting their importance in the context of the North East Scotland (Aberdeenshire), and Tayside / Perth and Kinross populations. Declining County These species receive the same protection as all bird species under the breeding Wildlife and Countryside Act 1981 (as amended), but are also represented on waders: the BoCC Red-list reflecting the long-term decline in their UK breeding curlew and populations. lapwing Records received through consultation have confirmed that these species occur at variable frequency along the OHL Route and that breeding territories are held where suitable habitat exists. The frequency and distribution at which these species occur along the OHL Route is considered to be representative of their broader geographic distribution at the Regional (Scottish) level. These species are therefore valued at a County-level reflecting their importance in the context of the North East Scotland (Aberdeenshire) and Tayside/Perth and Kinross populations.
7.4 Issues Scoped Out Operational effects have been scoped out as the Proposed Development will essentially be no different to the baseline conditions of the OHL Route; with the exception of permanent changes to woodland habitats as a result of essential operational corridor clearance and minor increases in the height of 73 towers. Effects of tree felling are addressed during the construction phase where the impact will initially be realised. Meanwhile, the minor increased height of a small number of towers is not anticipated to significantly alter the collision risk already posed to locally occurring and migratory birds by the existing OHL Route. This assumption is not expected to change should the increased tower heights deviate slightly within the limit of deviation.
CIEEM EcIA Guidelines state that the assessment process does not require consideration of effects on ecological features deemed to be below a predefined nature conservation value threshold. Therefore, an assessment of the effects upon features of Site level nature conservation value or below, or those which do not occur within the Proposed Development’s EZoI, have been excluded from further assessment (Table 7-7-8).
Table 7-7-8 – Ecological features scoped out
Feature Justification
Methven Moss Designated for active and degraded raised bog. SAC Located 5.2 km from the OHL Route; does not fall within the Proposed Development’s EZoI.
Dunkeld - Designated for clear-water lakes or lochs with aquatic vegetation and poor-moderate Blairgowrie nutrient levels; otter; slender naiad Najas flexilis; and very wet mires often identified by an Lochs SAC unstable ’quaking’ surface. Located 5.2 km from the OHL Route; considered too distant to fall within the Proposed Development’s EZoI.
Craighall Designated for mixed woodland on base-rich soils associated with rocky slopes. Gorge SAC Located 6.4 km from the OHL Route; considered too distant to fall within the Proposed Development’s EZoI.
Red Moss of Designated for active and degraded raised bog. Netherley SAC Located 6.5 km from the OHL Route; considered too distant to fall within the Proposed Development’s EZoI.
7-20 Feature Justification
Turflundie Designated for its important population of great crested newts. Wood SAC Located 7.9 km from the OHL Route; considered too distant to fall within the Proposed Development’s EZoI.
Firth of Tay Designated for estuaries; intertidal mudflats and sandflats; subtidal sandbanks; and harbour and Eden seal Phoca vitulina. Estuary SAC Located 9.7 km from the OHL Route; considered too distant to fall within the Proposed Development’s EZoI.
Garron Point Designated for narrow-mouthed whorl snail Vertigo angustior. SAC Located 9.9 km from the OHL Route; considered too distant to fall within the Proposed Development’s EZoI.
Loch of Designated for important populations of overwintering populations of greylag geese and Kinnordy SPA pink-footed goose. and Ramsar Located 1.8 km from the OHL Route; does not fall within the Proposed Development’s EZoI Site and hence sufficiently far away for it to be directly affected while significant effects on the more wide-ranging qualifying geese are considered highly unlikely on the basis that the works will be highly localised and there is an abundance of suitable (agricultural) foraging habitat along the OHL Route to which any disturbed birds can be displaced.
Loch Leven Designated for important populations of overwintering waterfowl, including cormorant, SPA and gadwall, goldeneye, pink-footed goose, pochard, shoveler, teal, tufted duck and whooper Ramsar Site swan as well as its overwintering waterfowl assemblage. Located 3.7 km from the OHL Route; does not fall within the Proposed Development’s EZoI and hence sufficiently far away for it or its associated qualifying interests to be directly affected while significant effects on the more wide-ranging qualifying geese are considered highly unlikely on the basis that the works will be highly localised and there is an abundance of suitable (agricultural) foraging habitat along the OHL Route to which any disturbed birds can be displaced.
Loch of Designated for important populations of overwintering populations of greylag geese. Lintrathen SPA Located 3.8 km from the OHL Route; does not fall within the Proposed Development’s EZoI and Ramsar and hence sufficiently far away for it to be directly affected while significant effects on the Site more wide-ranging qualifying geese are considered highly unlikely on the basis that the works will be highly localised and there is an abundance of suitable (agricultural) foraging habitat along the OHL Route to which any disturbed birds can be displaced.
Loch of Skene Designated for important populations of overwintering populations of greylag geese. SPA and Located 4.5 km from the OHL Route; does not fall within the Proposed Development’s EZoI Ramsar Site and hence sufficiently far away for it to be directly affected while significant effects on the more wide-ranging qualifying geese are considered highly unlikely on the basis that the works will be highly localised and there is an abundance of suitable (agricultural) foraging habitat along the OHL Route to which any disturbed birds can be displaced.
South Tayside Designated for important populations of overwintering populations of greylag geese and Goose Roosts pink-footed geese and general waterfowl assemblage. SPA and Located 4.7 km from the OHL Route; does not fall within the Proposed Development’s EZoI Ramsar Site and hence sufficiently far away for it or its associated qualifying interests to be directly affected while significant effects on the more wide-ranging qualifying geese are considered highly unlikely on the basis that the works will be highly localised and there is an abundance of suitable (agricultural) foraging habitat along the OHL Route to which any disturbed birds can be displaced.
Cairngorms Designated for important resident population of golden eagle. Massif SPA Located 6.2 km from the OHL Route; does not fall within the Proposed Development’s EZoI and hence sufficiently far away for it or its associated qualifying interests to be directly affected.
7-21 Feature Justification
Forest of Designated for important populations of breeding hen harrier, merlin, short-eared owl and Clunie SPA osprey. Located 7.8 km from the OHL Route; does not fall within the Proposed Development’s EZoI and hence sufficiently far away for it or its associated qualifying interests to be directly affected.
Fowlsheugh Designated for important populations of breeding seabirds, including fulmar, kittiwake, SPA guillemot, herring gull and razorbill as well as its general seabird assemblage. Located 9.5 km from the OHL Route; does not fall within the Proposed Development’s EZoI and hence sufficiently far away for it or its associated qualifying interests to be directly affected.
Firth of Tay Designated for important populations of overwintering waterbirds, including bar-tailed and Eden godwit, common scoter, cormorant, dunlin, eider, goldeneye, goosander, grey plover, Estuary SPA greylag goose and black-tailed godwit and breeding marsh harrier and little tern. and Ramsar Located 9.7 km from the OHL Route; does not fall within the Proposed Development’s EZoI and hence sufficiently far away for it or its associated qualifying interests to be directly affected and for more wide-ranging overwintering waterfowl (geese), significant effects are considered highly unlikely on the basis that the works will be highly localised and there is an abundance of suitable (agricultural) foraging habitat along the OHL Route to which any disturbed birds can be displaced.
Loch of Park Notified for basin fen and wet woodland. SSSI Located 0.5 km from the OHL Route; considered too distant to fall within the Proposed Development’s EZoI.
Balloch Moss Notified for raised bog. This SSSI is a discrete area, located 0.6 km from the OHL Route and SSSI therefore considered too distant to fall within the Proposed Development’s EZoI.
Gartwhinzean Notified for lowland neutral grassland. This SSSI is a relatively small, discrete area (1.76 ha) Meadow SSSI located 0.7 km from the OHL Route and therefore considered too distant to fall within the Proposed Development’s EZoI; supported by Scoping Response comments from Fossoway Community Council (see Table 7-7-1).
Den of Ogil Notified for scrub and valley fen. SSSI Located 0.8 km from the OHL Route; too distant to fall within the Proposed Development’s EZoI.
Back Burn Notified for lowland acid grassland and upland mixed ash woodland. Wood and Located 0.9 km from the OHL Route; too distant to fall within the Proposed Development’s Meadows SSSI EZoI.
Den of Airlie Notified for its bryophyte assemblage; invertebrate assemblage; river jelly lichen Collema SSSI dichotomum; upland mixed ash woodland; and whorled solomon's-seal Polygonatum verticillatum. Located 0.8 km from the OHL Route; too distant to fall within the Proposed Development’s EZoI.
Barmekin Botanical interests. Wood LNCS Located 0.15 km from the OHL Route; does not fall within the Proposed Development’s EZoI.
Mergie LNCS Botanical and aquatic interests. Located 0.5 km from the OHL Route; does not fall within the Proposed Development’s EZoI.
Arable habitat Arable land co-dominates the majority of the OHL Route along with improved grassland (below), in a wider agricultural landscape. Agricultural land covers over 70 % of Scotland51. Arable habitat is not included under legislative or conservation lists as a priority habitat type, and of reduced suitability to support protected and priority species other than badger which is considered separately.
7-22 Feature Justification This feature is considered to be of Site value only, thus is scoped out from further assessment.
Improved Improved grassland and grazing pasture co-dominates the majority of the OHL Route along grassland with arable habitat (above). Improved grassland is not included under legislative or conservation lists as a priority habitat type, and similar habitat is available for protected or priority species (primarily birds and badgers) in the surrounding area. This feature is considered to be of Site value only, thus is scoped out from further assessment.
Dense scrub Scrub habitats along the OHL Route are relatively species-poor, predominantly comprising (excluding dense stands of gorse or broom. Whilst adding a diverse structure to the other habitats, areas within scrub along the OHL Route is reflective of and frequent across the wider landscape. Scrub designated habitats are not included under legislative or conservation lists as a priority habitat type. sites) This feature is considered to be of Site value only, thus is scoped out from further assessment.
Coniferous Of woodlands surveyed along the OHL Route, coniferous plantation comprises a large plantation proportion. All stands were notably uniform and dense, with presumably limited associated woodland ground flora. Coniferous plantation woodlands are not included under legislative or (excluding conservation lists as a priority habitat type. areas within Commercial forestry plantation dominated by coniferous trees makes up three quarters of designated woodland cover across Scotland51 (remaining quarter considered to be native). Coniferous sites) woodland can support a smaller range of protected and generalist species however, when considered in isolation, large extents of plantation are considered to be of Site value only, thus is scoped out from further assessment.
Marshy Marshy grassland was mapped occasionally along the OHL Route. These areas are grassland predominantly species-poor and do not align with descriptions of priority habitats included (excluding under legislative or conservation lists. areas within This feature is considered to be of Site value only, thus is scoped out from further designated assessment. sites)
Flushes and A single flush was mapped in the centre of the OHL Route. It is located approximately 40 m springs from the OHL and beyond 100 m from the nearest Tower (227). As such, this flush is not (excluding considered to fall within the Proposed Development’s EZoI. areas within designated sites)
Swamp Two small, discrete patches of swamp were mapped by Towers 227 and 235, central to the (excluding OHL Route. These areas occur within improved and arable pasture, the latter along a minor areas within watercourse. designated Given the extent of these habitats and context amongst agricultural pasture, this feature is sites) considered to be of Site value only, thus is scoped out from further assessment.
Ponds Areas of standing water/ ponds occur relatively rarely along the OHL Route. A pond is present near Tower 294, but over 50 m from the tower base and located in a discrete area at the bottom of a sloping hillside; it was almost dry at the time of survey. A small pond is present within 50 m of Tower 104, however this has been modified as it has an artificial drain. A longer, narrow pond extends between Towers 104 and 105 and other ponds are present in this locality beyond 50 m from the OHL. All ponds there have been modified to some extent by the landowner, with some used as duck ponds. These ponds are therefore all valued at Site level. All other areas of standing water are beyond 50 m from the OHL. These discrete features are easily avoided by the Proposed Development, therefore not considered to fall within the Proposed Development’s EZoI.
7-23 Feature Justification
Wildcat This is an EPS which receives full protection under the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended) and is also an SBL species. The Mammal Society52 reported that the population size and range of wildcats in Scotland has declined since 1995 and is predicted to decline further. Their range, based on 1995-2016 presence data, includes the north-east52; however this species is associated with woodland edge habitats in the margins of mountains and moorlands62. The predominantly lowland agricultural and managed landscape within which the OHL Route extends is likely to be avoided by wildcat. Coniferous woodlands to the northern extent of the OHL Route, through Fetteresso Forest, Durris Forest, and Strathfinella LNCS may present relatively suitable habitat, but these areas are still considered to be sub-optimal as they are within actively managed commercial forestry. This species is not considered to occur within the Proposed Development’s EZoI.
Freshwater This is an EPS which receives full protection under the Conservation (Natural Habitats, &c.) pearl mussel Regulations 1994 (as amended); and an SBL species. (excluding This species is not considered to occur within an EZoI, beyond considerations to this species designation under River Dee SAC and River South Esk SAC. Based on previous considerations, freshwater under River pearl mussel populations are not thought to occur within non-designated watercourses Dee SAC and along the OHL Route. River South Esk SAC)
Invertebrates Invertebrates are not considered to occur within an EZoI, because the majority of (excluding infrastructure already exists and the footprint of temporary infrastructure associated with the freshwater Proposed Development will be small relative to the surrounding broadly homogenous pearl mussel) habitats and resources for invertebrates.
Great crested This is an EPS which receives full protection under the Conservation (Natural Habitats, &c.) newt Regulations 1994 (as amended); and an SBL species. The original Environmental Statement for the East Coast 400 kV Reinforcement Project (SHET, 2013)63 identified seven ponds within 250 m with potential to support great crested newts. Although none of these ponds will be directly affected by the OHL reinforcement works and access routes will avoid ponds, great crested newts also use terrestrial habitat in the wider area surrounding breeding ponds outwith the breeding season. However, six of the seven ponds (near Towers 227, 232, 242, 244, 248 and 294) are located in Tayside and Angus, along the section of the OHL Route which runs between Blairgowrie and just north of Kirriemuir; a part of Scotland which is not known to support populations of great crested newts (Baker et al., 201164). The seventh pond, which is located to the northwest of Perth near Tower 150, and is within a region which is known to support great crested newts, has since had a housing scheme built around it; the associated assessment for which concluded that great crested newts were unlikely to be present (15/01109/FLM). Consequently, this species is not considered to occur within an EZoI.
Amphibians All amphibians native to Scotland (except great crested newt and natterjack toad Epidalea (palmate newt, calamita65) receive limited protection under the Wildlife and Countryside Act 1981 (as smooth newt, amended), but only against trade (i.e. sale, barter, exchange, transport for sale, or advertise common frog, for sale or to buy). Common toad is an SBL species; other amphibians (except great crested common newt) are not on the SBL. toad; Standing water with relatively unmanaged surrounding terrestrial habitats, and riparian excluding habitats, which would support amphibians occur relatively occasionally along the OHL great crested Route. Common species of amphibian are likely to occur regularly within these suitable newt) habitats, but considered to enrich these resources at a Site level only.
62 The Mammal Society: Wildcat. Available: https://www.mammal.org.uk/species-hub/full-species-hub/discover-mammals/species-wildcat/ [Accessed July 2020] 63 SHET (2013). East Coast 400kV Reinforcement Project Environmental Statement (and associated appendices). 64 Baker, J., Beebee T., Buckley, J., Gent, A. and Orchard, D. (2011). Amphibian Habitat Management Handbook. Amphibian and Reptile Conservation, Bournemouth. 65 The Scottish distribution of natterjack toad is restricted to the coastal regions of south-west Scotland; this species is not considered further. 7-24 Feature Justification
Reptiles (slow All reptiles native to Scotland are SBL species and receive limited protection under the worm, Wildlife and Countryside Act 1981 (as amended), against intentional or reckless killing and common injury and trade. lizard, adder) Mosaics of habitats with suitability to support basking and foraging reptiles have been recorded occasionally along the OHL Route (e.g. heath, scrub, and relatively unimproved grasslands). Numerous dry-stone walls bisecting the landscape and woodland edge habitats offer suitable reptile features for sheltering. Common lizard were sighted twice during the course of the extended Phase 1 habitat and protected species surveys. Common species of reptile are likely to occur regularly within these suitable habitats, but considered to enrich these resources at a Site level only. As the reinforcement works are programmed to take place between April and October during the three successive years 2023-2025 (i.e. during the reptile activity period) it is anticipated that individuals will be able to move out of the way of advancing works (i.e. laying of temporary access tracks and establishment of working platforms. Consequently, and based on the anticipated low density at which common reptiles are expected to occur along the OHL Route, the risk of individuals being accidentally killed or injured is considered to be extremely low. Nonetheless, recommendations are made regarding the sensitive dismantling and reinstatement of dry stone walls and other features which may be used as refugia by reptiles.
Brown hare This is an SBL species. A stable population is present across the UK, including the north-east.. Brown hare exploit habitats along the OHL Route that also dominate the surrounding landscape. Brown hare were sighted on eight distinct occasions during the course of the extended Phase 1 habitat and protected species surveys. This feature is considered to be of Site value only, thus is scoped out from further assessment.
Roe deer Deer receive limited protection under the Deer (Scotland) Act 1996, which focusses on how deer may be taken or killed. A stable population size and range is present across Scotland52.. Deer exploit habitats along the OHL Route that also dominate the surrounding landscape. Roe deer was sighted on 12 distinct occasions during the course of the extended Phase 1 habitat and protected species surveys. Roe deer is considered to be of Site value only, thus is scoped out from further assessment.
Overwintering Many of the overwintering waterfowl which are anticipated to occur in proximity to the OHL waterfowl Route are expected to be associated with some of the many nearby SPAs, Ramsar sites and (excluding SSSIs. However, significant effects on overwintering waterfowl in general are considered greylag geese highly unlikely on the basis that the works will be highly localised and there is an abundance associated of suitable (agricultural) foraging habitat along the OHL Route to which any disturbed birds with Hare can be displaced. The only exception to this is greylag geese associated with Hare Myre, Myre, Monk Monk Myre and Stormont Loch SSSI, which is scoped into the assessment based on its closer Myre and relative proximity to the OHL Route than other designated sites such that roosting geese are Stormont more likely to experience disturbance from the proposed works. Loch SSSI) Overwintering waterfowl are therefore considered to be of no more than Site value and are thus scoped out from further assessment.
Typical Records received through consultation have confirmed that a range of species occur along breeding and the OHL Route which are representative of the associated lowland agricultural, wintering bird woodland / commercial forestry, and freshwater habitats. These are anticipated to include assemblages: moderate to highly abundant and regularly occurring common and widespread species as common and well as rare to occasional occurrence and low abundance of more scarce species. widespread The species which represent the general breeding and wintering bird assemblages of the species habitats associated with the OHL Route have been valued at a Site-level. While they enrich the biodiversity resource where localised populations exist, substantial and regular populations of the various species are unlikely to occur along the OHL Route relative to their
7-25 Feature Justification local or higher-level geographic reference populations. With the exception of accidental nest destruction and killing or injury of breeding birds’ eggs or young, which would be mitigated for through application of appropriate measures such as pre-works nesting bird checks and implementation of works exclusion zones, common passerines (songbirds) are typically at low risk from the impacts associated with the Proposed Development.
7.5 Assessment of Effects, Mitigation and Residual Effects
Mitigation by Design The opportunity to influence the design of the Proposed Development as part of biodiversity mitigation has been limited because the towers and OHL Route are already in existence and the exact location of temporary infrastructure (e.g. compounds) will be at the discretion of the successful Principal Contractor. Further, felling requirements to increase the width of the existing operational corridor to meet minimum clearance requirements will be essential to ensure safe maintenance of the operational OHL; thus, it is not possible to avoid felling in certain areas for biodiversity interests. Embedded mitigation relevant to this chapter includes tried and tested measures documented within: · GEMPs (Volume 4 Appendix 3.2: SHE Transmission GEMPs), and · SPPs for badger, bats, otter, red squirrel, birds, water vole, pine marten and birds66 (Volume 4 Appendix 3.3: SHE Transmission SPPs).
It is reasonable to assume protocols detailed within the GEMPs and SPPs will be implemented successfully. For clarity, embedded mitigations captured within the following particular GEMPs will be sufficient to address and control potential impacts associated with pollution events, such that pollution impacts have not been addressed through this assessment. · Oil storage and refuelling; · Working in or near water; · Working with concrete; · Watercourse crossings; · Waste management; and · Contaminated land.
Other GEMPs which will address and mitigate (fully or in part) potential impacts on habitat interests include: · Working in sensitive habitats; · Restoration; and · Bad weather.
Where mitigation measures relevant to protected species either differ from that presented in the SPPs or are considered important to highlight for specific elements of the Proposed Development (e.g. felling), this is captured as additional mitigations herein and supersedes that presented in the SPPs.
All additional mitigation will be captured in and delivered through the CEMP.
66 SHE Transmission Beaver SPP is in preparation at the time of writing. Mitigation measures required for beaver are included as additional mitigation (BD19) in the absence of a published SPP. It is anticipated that these mitigation measures will align with the SHE Transmission Beaver SPP (due to be published in early 2021). 7-26 Construction Phase Habitat Loss Design Solutions and Assumptions Tree felling to achieve a safe operational corridor either side of the OHL Route will result in permanent and unavoidable loss of associated woodland habitat. However initial studies (not including resilience studies to be conducted post-consent) reported in Volume 4 Appendix 3.1: Forestry advise that a well-maintained operational corridor exists through the majority of woodlands along the OHL Route, therefore woodland habitat loss will be relatively marginal. Volume 4 Appendix 3.1: Forestry identifies areas where individual trees amongst woodlands will require felling in relation to the upgrade of the OHL from 275 kV to 400 kV and three distinct areas where relatively greater woodland clearance (albeit still minor) will be required to create a windfirm edge. Additionally, where larger sections of woodland require felling to create a windfirm edge, opportunities for restocking to reduce the overall permanent woodland habitat loss have been identified in Volume 4 Appendix 3.1: Forestry. Ultimately, it is anticipated that the largest single area of woodland that would be permanently lost will be approximately 6 ha at Mundernal Wood, a plantation near Towers 473 to 485. This Chapter addressed woodland habitat loss based on the findings of Volume 4 Appendix 3.1: Forestry. It is assumed that the remaining works associated with the Proposed Development will result in temporary habitat loss, perceived as habitat degradation, as habitats are likely to restore in the short- term. Re-conductoring and re-insulation is generally undertaken in sections of between 5 to 15 towers in length, with each section taking approximately one to two weeks to complete. The locations of temporary site compounds remain broadly unknown at this stage of the assessment (these will be determined by the successful Principal Contractor). Therefore, this chapter pragmatically assumes that temporary site compounds will be micro-sited to avoid sensitive receptors.
No new towers will be erected as part of the Proposed Development; however, up to 73 towers will be extended as detailed in Chapter 3, Section 3.4. To allow for these extensions, temporary line diversions will be constructed. These are likely to be supported by temporary masts secured by stays although there is a possibility that conventional towers with below-ground foundations may be required. These are assumed to remain in situ for no more than six months. The location of the temporary masts will be within 100 m of the tower being extended as illustrated in Figure 3.2, the precise location is not yet defined; however, it is assumed that they will extend immediately adjacent to the OHL Route with relatively few ecological sensitivities at each extension and that temporary masts will be micro-sited to avoid sensitive receptors. The assessment of habitat loss from this element of the Proposed Development has been addressed for towers pre-identified to be of moderate-high ecological sensitivity only, as these locations represent the extent of baseline data available for IEFs upon which this assessment is based.
Access routes will broadly follow those previously used to facilitate earthwire replacement works in 2017.
Description of Effects
Designated Sites Slender green feather-moss of qualifying interest at Pitkeathly Mires SAC is not present along the OHL Route (see Appendix 7.3 Pitkeathly Mires National Vegetation Classification Survey Report); it is localised to areas beyond the OHL Route and beyond the proposed access routes. This species will therefore not be directly affected by the Proposed Development.
7-27 Woodlands extend along the banksides of the River Dee SAC, River Tay SAC and River South Esk SAC. These SACs are designated for aquatic interests (a combination of otter, freshwater pearl mussel, Atlantic salmon and brook lamprey). Whilst woodland is not a qualifying interest of these SACs, it is encompassed within the boundary of each SAC and may offer supporting habitat to otters (associated with River Dee SAC and River Tay SAC); and shade / cover to fish and freshwater pearl mussel (associated with River Dee SAC, River Tay SAC and River South Esk SAC). Volume 4 Appendix 3.1: Forestry advises that a well-maintained operational corridor exists through the lowland mixed deciduous / wet woodland either side of the River Dee; therefore, there is no requirement for woodland clearance for the OHL Route within the River Dee SAC. An extension to Tower 495, which falls within the River Tay SAC boundary, will be required; and associated temporary diversion over the SAC. Volume 4 Appendix 3.1: Forestry advises that modest felling (measurable in number of trees, not forest felling area) is possible on the south bank and probable felling is anticipated to extend an existing clearing on the north bank to accommodate a temporary mast. There is no requirement for woodland clearance for the OHL Route along the banks of watercourses included under the River South Esk SAC. Volume 4 Appendix 3.1: Forestry advises that the current vertical separation is maintained between small trees within the operational corridor and the OHL. The low stature of trees and small coverage at these locations represents cleaning rather than felling requirements.
The OHL Route spans the River Tay SAC at multiple locations. Volume 4 Appendix 3.1: Forestry only identified the requirement for felling of individual trees amongst wet woodland at Lunan Burn (near Tower 205), where open grown trees cross with some close to the conductor. Some other individual trees require further assessment as part of the resilience study, however there will be no forestry impact from the upgrade works. Therefore, woodland habitat loss in relation to the River Tay SAC is anticipated to be marginal, in the region of individual trees.
An extension to Tower 148 which is located in proximity to the River Tay SAC will be required and therefore, a temporary line diversion will extend over the SAC. Volume 4 Appendix 3.1: Forestry did not identify any felling requirements in relation to this tower extension.
Devon Gorge SSSI woodland extends over a deep gorge with steep sides between Towers 40-44. Volume 4 Appendix 3.1: Forestry advises that no trees within the steep gorge sides require felling where the OHL Route traverses the gorge. At the head of the slopes, distances to individual field boundary trees will be assessed for resilience as part of future studies. An individual tree (larch) may require felling, but no additional woodland clearance is anticipated. The OHL Route spans Candyglirach LNCS between Towers 510 and 513, for approximately 600 m. Volume 4 Appendix 3.1: Forestry advises that the operational corridor east of the OHL between Towers 511 and 513 is constrained and modest windblow has occurred within the crop of Scots pine. Up to 1 ha of felling will be required to present a windfirm edge, of which 0.5 ha could subsequently be restocked. This represents a marginal permanent loss of woodland habitat from the LNCS. The OHL Route spans Loch of Park LNCS between Towers 501 and 510, which encompasses areas of upland birchwood and native pinewood. Volume 4 Appendix 3.1: Forestry identifies the requirement for felling of individual (eight) Scots pine trees adjacent to a public road near Towers 501 to 504 that may present a resilience issue and require felling. This would represent a permanent loss of woodland habitat from the LNCS, however in the region of individual trees rather than woodland cover. PAWS associated with Strathifinella LNCS occurs between Towers 410 and 422. Volume 4 Appendix 3.1: Forestry advises that a well-maintained operational corridor exists therefore no additional felling will be required there. There are no other habitat loss considerations through Strathifinella LNCS.
7-28 The boundary of Gannochy Gorge SSSI is located immediately adjacent to the OHL Route between Towers 373 and 374, however the operational corridor at this location is not anticipated to overlap with this SSSI. No direct loss of SSSI notified habitat is therefore anticipated. Volume 4 Appendix 3.1: Forestry advises that the operational corridor is not well defined at the crossing of the River North Esk between Towers 373 and 374, and this Chapter notes that connecting woodlands between the operational corridor and Gannochy Gorge SSSI may support the beetle and lichen assemblages for which the SSSI is notified. However, the young stage growth does not present an immediate felling requirement therefore no habitat loss impacts are predicted for this SSSI. All impacts on designated sites resulting from felling would be permanent, but of low spatial impact due to the habitat loss anticipated to be marginal relative to the wider habitat under these designations (predominantly being loss of individual trees). Ultimately therefore, the impact of felling on designated sites is considered to represent an impact of low magnitude which would be of Minor Adverse significance.
Access routes taken through designated sites are not anticipated to involve any loss of habitat as they will be protected by use of ATV, the laying of trackway or other ground protection media (e.g. bog mats). This aligns with the GEMP for working in sensitive habitats and watercourse crossings. At worst it is anticipated that habitats within designated sites may be temporarily damaged / degraded as considered under Habitat Degradation and Fragmentation.
Habitats Approximately 284 ha of woodland within 40 m either side of the OHL Route is listed on the Ancient Woodland Inventory (including ASNW and PAWS). The three areas of woodland identified in Volume 4 Appendix 3.1: Forestry requiring the (relatively) largest areas of clearance to create a windfirm edge do not extend over areas included under the Ancient Woodland Inventory. There may be localised felling of individual trees which fall under broader areas designated as ASNW or PAWS. ASNW woodlands are considered irreplaceable, however the loss of individual trees to maintain a safe operational corridor for the upgrade of the OHL from 275 kV to 400 kV would be unlikely to threaten the long-term integrity of the wider ancient woodland network. This is anticipated to result in a permanent effect of low spatial magnitude and represent an effect of Minor Adverse significance in a worst-case scenario. Similarly, felling of individual trees amongst non-designated broadleaved and mixed woodlands along the OHL Route to maintain the operational corridor will result in a permanent habitat loss. However, again this would be unlikely to alter the function of the adjoining woodland. This would be of low spatial magnitude and Minor Adverse significance. Watercourse crossings would be unlikely to result in a habitat loss of the running water environment. No new watercourse crossings are anticipated to be required (i.e. to facilitate access) and the GEMP for working in proximity to watercourses will be implemented at all existing watercourse crossings.
Protected Species (not including birds) Felling impacts would result in a loss of foraging habitat for species with an affinity to such habitats including bats, badgers, pine marten and red squirrel; as well as riparian mammals where felling will occur along watercourses. However, felling requirements predominantly encompass the loss of individual trees, with the exception of three larger areas where <0.5 ha, 0.5 ha and 6 ha of permanent woodland loss at each larger area will be required respectively. Permanent loss of foraging habitat is therefore considered to represent an impact of low magnitude which is predicted to represent an effect of no more than Minor Adverse significance.
7-29 In some places, the removal of individual trees, cleaning trees or partial woodland clearance, particularly coniferous plantation woodland, may even open areas for colonisation by a more diverse range of plants which in turn may provide a broader range of foraging opportunities for locally occurring species, thus potentially representing a Minor Beneficial effect.
The loss of species’ resting sites due to habitat loss (e.g. badger setts, bat roosts) is addressed separately further below.
Birds The removal of individual trees and certain areas of woodland along sections of the OHL Route to maintain the operational corridor will result in the loss of foraging, sheltering and nesting habitat for locally occurring birds. The effects of damage and destruction of nests on birds is discussed below under Loss of, Obstruction of, or Disturbance to Species’ Resting/Nesting Sites. The three largest areas (relatively) of felling will involve plantation forestry which is typically of low ecological value, providing limited foraging resource. Furthermore, as described above, felling will be limited. The largest area of felling at a single section is anticipated to cover approximately 20 ha, however when incorporating restocking opportunities, felling at this specific area would represent a temporary loss of 14 ha and permanent loss of 6 ha. Any sections which involve the removal of individual broadleaved trees or edge woodland are anticipated to represent a limited proportion of the total lost woodland. The loss of woodland is mainly anticipated to affect locally occurring species of the associated breeding and wintering bird assemblage, predominantly common and widespread passerines. It will not affect declining breeding waders which would occur in open moorland and grassland habitats. It is also unlikely to significantly affect any rare and vulnerable breeding raptors, other than through the potential loss of nest sites which is discussed below. Consequently, based on the limited extent and general low ecological value of the woodland to be removed, the loss is considered to represent an impact of low magnitude which is predicted to represent an adverse effect of no more than Minor Adverse significance.
In some places, the removal of woodland, particularly coniferous plantation woodland, may even open areas for colonisation by a more diverse range of plants which in turn may provide a broader range of nesting and foraging opportunities for locally occurring birds, thus potentially representing a Minor Beneficial effect.
Mitigation During Construction BD1: Whilst at this stage of the EIA it is assumed that felling requirements pertain to individual trees and three specific areas to create a windfirm edge, a woodland resilience study is being undertaken. Only areas of woodland (including designated and non-designated) that are identified as requiring essential, unavoidable felling will be subject to felling. Wherever possible, woodland will be retained, see Volume 4 Appendix 3.1: Forestry. BD2: The method statement prepared for works within Pitkeathly Mires SAC and SSSI will be adhered to (included in Appendix 7.3: Pitkeathly Mires National Vegetation Classification Survey Report).
BD3: Consent from NatureScot for felling woodland through Devon Gorge SSSI will be sought prior to commencement of works. Consent will also be sought for works within the Pitkeathly Mires SSSI designation.
BD4: There will be no site compounds located within 50 m of designated sites. There will be no refuelling activities within 50 m of designated sites.
7-30 BD5: Dry-stone walls and boundary features will be dismantled by hand and then reinstated upon completion of works in order to retain their integrity as habitat features for reptiles, amphibians, small mammals and invertebrates. These works should be undertaken in appropriate weather conditions during the reptile and amphibian active season (typically taken as being between April and October (inclusive)) in order to avoid their hibernation period and sub-optimal weather conditions for their activity. BD6: A portion of felled tree stems and limbs will be retained in piles within the operational corridor (subject to landowner agreement) to increase connectivity for small mammals, create habitat resources for invertebrates, reptiles and amphibians, and in turn provide new foraging opportunities for protected species such as badger, pine marten and bats.
BD7: An ECoW will be appointed to provide on-site guidance on adherence to relevant practices outlined in the GEMPs and SPPs to minimise habitat loss and avoid / minimise the risk of adverse impacts on protected species. The ECoW presence will be full-time during works within SACs and SSSIs. BD17: The loss of woodland habitat through permanent forestry loss to widen the operational corridor either side of the OHL Route will be off-set through off site compensatory planting. The compensatory planting excludes felling which would be within the existing 275 kV OHL operational corridor for which consent is already in place to manage trees for operational safety.
Residual Effect The residual effects of habitat loss on SACs valued at the International level, SSSIs valued at the National level, and LNCS valued at the Local level would remain permanent, of low spatial magnitude and ultimately of Minor Adverse significance (i.e. not significant).
Loss of individual trees amongst woodland listed on the AWI and valued at the County level would have a residual permanent effect of low spatial magnitude as this cannot be replaced once lost, and it is precautionarily assumed that much of this is true ASNW (as opposed to potentially non-native PAWS), which would be of Minor Adverse significance (i.e. not significant). Off-site compensatory woodland planting will off-set the loss of non-designated woodland outside of the existing 27 kV OHL operation corridor, and is predicted to result in a Neutral residual effect. Whilst not considered an IEF, some areas of the felled coniferous plantation areas may receive a beneficial effect where heath is successfully established in place of felled trees. The residual effects of habitat loss for protected species and birds would be of Negligible significance (i.e. not significant); noting loss of resting / nesting sites is addressed separately further below. Some species may even receive a beneficial effect where new foraging and shelter opportunities become available for birds, mammals, amphibians, reptiles and invertebrates in place of felled trees.
Overall, this assessment is made with probable confidence. Habitat Degradation and Fragmentation Design Solutions and Assumptions
The following GEMPs relevant to habitat degradation and fragmentation will be implemented: working in sensitive habitats; restoration; and bad weather. In particular, the GEMP for working in sensitive habitats sets out suitable access protocols to avoid and minimise disturbance to sensitive habitats such as peat-based heaths and mires located along the OHL Route. As stated above, the GEMPs will also ensure pollution events that may result in habitat degradation are avoided or reasonably mitigated for.
Access routes will broadly follow those previously used to facilitate earthwire replacement works in 2017.
7-31 The assessment of habitat degradation and fragmentation resulting from tower extensions and installation of temporary diversions has been addressed for towers pre-identified to be of moderate- high ecological sensitivity only, as these locations represent the extent of baseline data available for IEFs upon which this assessment is based.
Description of Effects
Designated Sites Woodland along the banksides of the River Dee SAC, River Tay SAC and River South Esk SAC are assumed to provide structural integrity to the banksides. Felling of these trees without due care could result in destabilisation of the banksides and degrade the riverine habitats. Works associated with spanning the River Dee SAC, River Tay SAC and River South Esk SAC are not anticipated to cause a barrier effect to the passage of aquatic species interests. It is not anticipated that increasing the operational corridor through felling of individual trees within any designated sites (including SACs, SSSIs and LNCSs) would result in further fragmentation of the habitat there. Volume 4 Appendix 3.1: Forestry advises loss of individual trees may be required on the banks of River Dee SAC, River Tay SAC and River South Esk SAC and within the LNCSs. This loss is insignificant compared to the existing operational corridor already measuring up to 60 m in total (30 m either side of the OHL Route). Access routes through Pitkeathly Mires SAC and SSSI have potential to cause habitat degradation, in particular where the routes will unavoidably extend across non-qualifying fen habitats at two locations. Slender green feather-moss of qualifying interest at Pitkeathly Mires SAC is not present along the OHL Route; it is localised to areas beyond the OHL Route and beyond the proposed access routes. This species will therefore not be directly affected by the Proposed Development. However, potential exists for vehicular access to cause indirect disturbance to this species, by degrading the habitat upon which it relies. In the absence of works-specific controls, the condition of slender green feather-moss and the fens and connected qualifying basin fens could be degraded. Such impacts are predicted to be of medium magnitude but short-term; this in combination with the International level value of the SAC and its sensitive basin fen and rare bryophyte qualifying interests means that the effects could be of Moderate Adverse significance.
Access routes across the remainder of Pitkeathly Mires SAC and SSSI and works localised to tower bases have a reduced potential to result in adverse effects on this SAC and SSSI as they will be localised to non-qualifying heathland and acid grassland habitats. It is noted that the access routes to be used have been established through heathland and acid grassland from previous works to the OHL Route and agreed agricultural practices; as such it is not anticipated that temporary trackway will be used and further habitat fragmentation is unlikely. Following the GEMP for working in sensitive habitats, it is anticipated that ATVs will be used to access areas within Pitkeathly Mires SAC and SSSI. Access routes, working platforms and site compounds in other designated sites (e.g. Devon Gorse SSSI, Candyglirach LNCS, Loch of Park LNCS and Strathifinella LNCS) are expected to involve protection of associated habitats through the use of trackway or other ground protection media (e.g. bog mats). Nonetheless, these habitats are still likely to experience some degree of damage / degradation as a result of being disturbed. However, the disturbance to these habitats will be temporary and they are anticipated to recover rapidly (i.e. within one year) following completion of the works and removal of the ground protection media. This effect is therefore predicted to be of Negligible significance.
7-32 Habitats
Access routes requiring trackway, working platforms and site compounds are expected to result in temporary damage / degradation of heath habitats. The extent of this temporary damage is unknown due to lack of information on temporary infrastructure; however, this effect would be short-term and of low spatial magnitude, and therefore of no more than Minor Adverse significance. Running water, considered a sensitive receptor valued at the Local level, could be degraded through installation of temporary watercourse crossings. However, these would be sensitively installed and of low spatial magnitude, and disturbed banksides would be reinstated back to their former condition upon completion of works. This aligns with the GEMP for watercourse crossings. Therefore, effects of these impacts on running water are not predicted to be significant.
Invasive non-native species identified in proximity to running water may spread further if interfered with during construction works. Further spread of invasive non-native species would result in an effect of low spatial magnitude and could be medium-term, but not significant.
Protected Species (not including birds) It is not anticipated felling requirements to maintain the operational corridor through woodland would result in further fragmentation of habitat resources for protected species. The operational corridor would still function as a commuting route for bats and other terrestrial mammals, offering a sheltered edge and foraging resource. Additionally, scrub and shrub habitats occur along the majority of the existing operational corridor between woodlands (both coniferous plantations and semi-natural broadleaved or mixed woodlands) which provide some connectivity and cover for species traversing the operational corridor. Access routes will be used temporarily, therefore would be unlikely to cause fragmentation of territories used by protected species. The remainder of works associated with the Proposed Development will be localised to existing towers, and as such are unlikely to result in further modification or degradation to habitats in current use by protected species.
Birds The proposed construction works are not anticipated to significantly affect birds through habitat degradation and fragmentation due to the pre-existence of the OHL Route and the discrete nature and short duration of the works.
Mitigation During Construction
BD2: The method statement prepared for works within Pitkeathly Mires SAC and SSSI will be adhered to (included in Appendix 7.3: Pitkeathly Mires National Vegetation Classification Survey Report). BD4: There will be no site compounds located within 50 m of designated sites. There will be no refuelling activities within 50 m of designated sites. BD6: A portion of felled tree stems and limbs will be retained in piles within the operational corridor (subject to landowner agreement) to increase connectivity for small mammals, create habitat resources for invertebrates, reptiles and amphibians, and in turn provide new foraging opportunities for protected species such as badger, pine marten and bats. BD7: The ECoW will provide on-site guidance on adherence to practices outlined in the GEMPs to minimise habitat degradation, for watercourse crossings, avoid and control pollution events, and avoid the spread of invasive non-native species. BD8: Invasive non-native species will be demarcated by the ECoW. No works will occur within at least 7 m of identified invasive non-native species to prevent further spread.
7-33 Residual Effect
Mitigations presented within the GEMPs are industry-standard and effective. Specific mitigations relevant to felling, access and works within designated sites are anticipated to be easily and successfully implemented. As such, the following assessment is made with certain / near certain confidence. The residual effects of habitat degradation on SACs valued at the International level, SSSIs valued at the National level, and LNCS valued at the Local level would be of low spatial magnitude and short- term; and ultimately of Negligible significance (i.e. not significant). Degradation of habitats out with designated sites considered to be IEF valued at the Local level (including heaths, mires) and running water valued at the County level, would have a residual effect of low spatial magnitude and short-term; and would ultimately be of Negligible significance (i.e. not significant). The residual effects of habitat degradation on protected species considered to be IEF and valued at the Local level (including badger, otter, beaver, bats, fish) and birds, pine marten, and red squirrel valued at the County would be of low spatial magnitude and short-term; and ultimately of Negligible significance (i.e. not significant).
Killing of, and Injury to Species Design Solutions and Assumptions Mitigations presented in the GEMPs and SPPs include protocols to avoid indirect killing of, and injury to, protected species.
Description of Effects
Designated Sites There are no anticipated effects.
Protected Species (not including birds) There is potential for incidental killing of or injury to protected species through general construction activities (e.g. through accidental vehicle collision or entrapment).
Felling trees with undetected bat roosts could result in reckless killing of or injury to bats. Similarly, felling of undetected red squirrel dreys or pine marten tree den sites could result in killing of or injury to these species.
Effects associated with mortality or injury of protected species would be permanent but is anticipated to be of low spatial magnitude; and therefore of no more than Minor Adverse significance (i.e. not significant).
Birds The most likely risk of killing or injury of birds during construction is through the damage or destruction of active nests, which is discussed below in relation to Loss of, Obstruction of or Disturbance to Species’ Resting / Nesting Sites.
7-34 There is also a potential risk that some birds, particularly large, less agile birds such as geese, swans and large raptors may be at risk of colliding with the guy cables of temporary masts used during tower extensions, particularly if these are sited in ornithologically sensitive areas, such as near known breeding or roosting locations. As all works are programmed to take place between April and October when the majority of overwintering geese and swans are not present this is unlikely to pose a significant risk to the populations of such species. However, several of the tower extensions, and hence their associated temporary diversion masts, are located in areas where larger species of rare and vulnerable breeding raptor (i.e. specially protected species listed on Schedule 1 or EU Annex I) are known to occur, particularly in the northern half of the OHL Route near Kirriemuir, Laurencekirk and Banchory. The ornithologically sensitive areas of known raptor activity are based on data presented in Volume 4 Appendix 7.4: Bird Consultation Results and Volume 4 Appendix 7.5: Confidential Bird Data. Although the risk of collision is anticipated to be low and the number of individuals which might be affected is likely to be very small, the lower abundance and higher (County level) conservation value of such species means that the effects of such impacts could be as high as Moderate Adverse significance.
Mitigation During Construction BD7: The ECoW will monitor any pollution events and advise on the requirement for spill kits or other reactive measures. The ECoW will deliver pre-construction inductions to all site workers on species likely to be encountered, known resting sites in the works area, and controls in the relevant GEMPs and SPPs which will avoid reckless killing of, or injury to protected species. BD9: Pre-construction surveys for badger, otter, water vole, pine marten, red squirrel and bats will be undertaken to identify the current use of and newly established resting sites along the whole of the OHL Route. Pre-construction survey requirements are set out in the existing SPPs, which states the validity period of survey data for most species as 12 months. This additional mitigation is raised to highlight the essential requirement that pre-construction surveys be undertaken due to the lapse in time between baseline assessments and construction, as well as because baseline surveys did not cover the entire OHL Route. It is anticipated that this will merit a planning condition. Further details on pre-construction surveys are included in relation to mitigation for Loss of, Obstruction of or Disturbance to Species’ Resting / Nesting Sites. BD18: All temporary masts with guy cable supports located in ornithologically sensitive areas will be fitted with bird diverters to increase their visibility to birds and thereby reduce the risk of collision.
BD19: Pre-construction surveys for beavers will be undertaken following relevant best practice, alongside other pre-construction ecology surveys set out in the relevant SPPs.
Residual Effect The residual effects associated with mortality or injury to species, whether associated with a designated site or legally protected and occurring elsewhere along the OHL Route, and regardless of their nature conservation value, would be permanent (worst-case). Residual effects would however be of low spatial magnitude because mitigations identified above would ensure any instances would be incidental (worst-case). Ultimately therefore, residual effects are predicted to be of Minor Adverse significance (i.e. not significant).
Following the implementation of appropriate mitigation, detailed above, the risk of rare and vulnerable birds of conservation concern colliding with cable stays of temporary masts is predicted to be significantly reduced such that the residual effect is anticipated to be no worse than Minor Adverse significance (i.e. not significant).
7-35 Loss of, Obstruction of, or Disturbance to Species’ Resting/Nesting Sites Design Solutions and Assumptions The mitigation hierarchy set out in each SPP will be adhered to. This primarily sets out that all identified sheltered resting sites associated with those protected species will be retained / avoided in the first instance. The SPPs also set out that works will primarily maintain a 30 m buffer around resting sites (200 m for natal otter holts) to avoid / reduce potential disturbance impacts. Where this exclusion zone cannot be maintained, or a feature must unavoidably be destroyed as a last resort, the SPPs stipulate that a licence will be sought from NatureScot. In the absence of a published Beaver SPP, it is assumed that these measures relating to mitigation hierarchy, exclusion zones and licensing will apply to beavers and their resting sites; this is committed through additional mitigation (BD19).
Further, the GEMP for working in or near watercourses states that works within 10 m of watercourses will be avoided and a vegetation buffer maintained where possible. This approach is anticipated to retain riparian corridors and minimise disturbance.
Where resting sites associated with arboreal mammals (bats, pine martens and red squirrel) occur within an area requiring felling to extend the existing operational corridor, it is assumed that there would be no satisfactory alternative to retain these resting sites and as such a licence would be obtained from NatureScot. It is assumed that all construction works will be undertaken during hours of daylight. The assessment of loss of, obstruction of, or disturbance to species’ resting / nesting sites resulting from tower extensions and installation of temporary diversions has been addressed for towers pre- identified to be of moderate-high ecological sensitivity only, as these locations represent the extent of baseline data available for IEFs upon which this assessment is based.
Description of Effects
Designated Sites Species associated with the River Dee SAC, River Tay SAC and River South Esk SAC are not anticipated to be affected by the Proposed Development; assuming that works will maintain a 10 m buffer from the waters’ edge, 30 m buffer from any identified resting sites or features used by the qualifying interests, and 200 m from natal otter holts as per the relevant GEMPs and SPPs.
There is a low risk of greylag geese roosting at Hare Myre, Monk Myre and Stormont Loch SSSI being disturbed by construction activities. This is primarily due to the fact that the construction works are programmed to take place between April and October in each year of the works, during which migratory greylag geese are only likely to be present in substantial numbers in the October. However, at approximately 170 m away there is potential for any visual or noise disturbance associated with the works in that month to cause disturbance to roosting geese. While such impacts are predicted to be of low magnitude, the National level value of the SSSI and its notified interests means that the effects could be of Moderate Adverse significance. There are no specific species associated with Devon Gorge SSSI or the LNCSs considered IEFs.
7-36 Protected Species (not including birds)
At least one badger sett occurs within 30 m of tower bases along the OHL Route and seven setts occur within 30 m of access routes (noting that only 50 % of the OHL Route has been surveyed). All of these setts have potential to be disturbed by general construction works associated with the Proposed Development. In open arable areas where no felling is required, disturbance is likely to be low as no highly noisy or intense vibrational works are anticipated. For setts identified in woodland sections where felling is required, disturbance may be moderately intense. No setts have been identified within woodland directly required to be felled. However, because badgers are very active within distinct territories along the OHL Route, potential exists for new setts to become established within the areas subject to felling during the time that will lapse prior to the commencement of works. Therefore, there is potential for any such newly established setts within the felling areas to be lost, obstructed or damaged. Based on the current data available however, no badger setts are anticipated to be destroyed or damaged as a result of the Proposed Development.
In the absence of information on the location of temporary infrastructure, including site compounds, there is potential for these structures to obstruct, damage or destroy identified badger setts, as some setts have been identified in open areas directly under the OHL Route and adjacent.
Disturbance of badger setts is predicted to be of low spatial magnitude due to the extent of works along the OHL Route through multiple territories, but of short-term duration. Potential for temporary infrastructure to directly interfere with setts would be of relatively greater impact and longer-term. Overall, a precautionary and worst-case assessment is made of Moderate Adverse significance. Riparian mammals and their resting sites are not anticipated to be disturbed during works associated with the Proposed Development based on limited evidence of their presence in combination with standoff distances set out in the GEMPs and SPPs. There are not anticipated to be any highly noisy or intense vibrational works that would disturb fish passage or spawning.
Felling required to maintain a safe operational corridor for the upgrade of the OHL from 275 kV to 400 kV has potential to result in the loss of bat roosts, where they occur within individual trees subject to felling. Furthermore, roosts located in retained trees immediately adjacent to areas subject to felling may be indirectly affected by disturbance from the felling works or from permanent changes to their immediate surrounding habitat (i.e. exposing the roost) causing roost abandonment. Approximately 10 % of the woodland assessed along the OHL Route is considered to be of high suitability to support roosting bats; 30 % of woodland is considered to be of moderate suitability; and 60 % is considered to be of low suitability. Within the three largest areas subject to felling to create a windfirm edge, identified in Volume 4 Appendix 3.1: Forestry, woodlands have been assessed to be of low or moderate bat roost suitability. Therefore, whilst the number of roosts within woodland subject to felling is unknown at this stage, it is likely that a relatively low proportion of roosts could be affected. This is in combination with the low number of trees initially identified in Volume 4 Appendix 3.1: Forestry as requiring felling (forestry resilience study to be undertaken seperately). In the absence of mitigation, this effect would be permanent and has precautionarily been assessed to have potential to be of medium spatial magnitude. The effects on bats could therefore be of Moderate Adverse significance (worst case).
7-37 Felling also has potential to affect other arboreal mammals. No red squirrel dreys have been identified; however undetected or newly established dreys could occur in areas of mixed woodland along the OHL Route, which could be lost or disturbed. Similarly, no pine marten den sites have been identified; however potential exists for felling to result in the loss of or disturbance to undetected or newly established den sites in areas where relatively high activity has been recorded (Fettereso Forest, Durris Forest, Loch of Park LNCS, and Strathifinella LNCS). In the absence of mitigation, this effect would be permanent and has the potential to be of moderate spatial magnitude; and could therefore be of Moderate Adverse significance (worst case).
Birds There is potential for active birds’ nests to be damaged or destroyed particularly where they are built on actual towers or where works are required around nests, including tree felling. Installation of temporary tracks to allow access to tensioning towers for machinery associated with re-conductoring may also result in damage or disturbance of nests if access occurs in the breeding season (March- August inclusive). However, the total area involved in those works is anticipated to be small. There is also potential for breeding birds to be disturbed by construction works and felling activities conducted near their nest sites. This could result in the abandonment and failure of the nest in the year of the works. This effect would be greatest in areas where woodland felling or temporary access track installation is required prior to conductor replacement, in the vicinity of tensioning towers where the work associated with the conductor replacement would be concentrated, and around locations where towers need to be extended. Around towers where the works are limited to insulator and conductor replacement, disturbance is predicted to be much less intensive and of relatively short duration.
For species of the general breeding bird assemblage, the number of nest sites which could potentially be affected is expected to be small and is unlikely to result in any measurable effect on the local populations of the species concerned. Any such effects on general breeding birds are therefore considered to be Negligible and not significant. There is also the possibility that the works could impact on the nests of rare and vulnerable breeding raptors (i.e. specially protected species listed on Schedule 1 or EU Annex I) and declining breeding waders. The damage, destruction or disturbance of such species’ nests is likely to result in the loss of any nesting attempt or production of young in the year of the works, unless the birds were to go on and initiate a second nesting attempt elsewhere. Although the number of nests which might be affected is likely to be very small, the lower abundance and higher (County level) conservation value of such species means that the effects of such impacts could be as high as Moderate Adverse significance.
Since all birds’ and their nests are legally protected, their damage and/or destruction could constitute an offence. Species listed on Schedule 1 of the Wildlife and Countryside Act are also protected from disturbance, including their dependent young. Consequently, standard mitigation measures are presented below in order to prevent such instances occurring as a result of the construction works.
7-38 Mitigation During Construction
BD9: Pre-construction surveys for badger, otter, water vole, pine marten and red squirrel will be undertaken to identify the current status of identified resting sites and any newly established resting sites along the whole of the OHL Route (bats addressed separately further below). They will also identify any protected species licencing requirements, including the potential to close/remove existing resting sites and provide alternative, artificial shelters, such as badger setts or pine marten dens. Pre-construction survey requirements are set out in the existing SPPs, which state the validity period of survey data for most species as 12 months. This additional mitigation is raised to highlight the essential requirement that pre-construction survey be undertaken due to the lapse in time between baseline assessments and construction, as well as because baseline surveys did not cover the entire OHL Route. It is anticipated that this will merit a planning condition. BD10: For badgers, an exclusion zone in which no works (including felling) will take place will be established around setts along the OHL Route and proposed access routes, which will be physically marked out prior to commencement of works. The minimum buffer around entrances of setts in current use will be 20 m for felling activities, in line with Standard Forestry Operations Licence conditions, and 30 m for all other activities. For felling activities, trees within the 20 m exclusion zones will only be felled by hand or by a harvester reaching in from outside of the exclusion zone. Consideration should be given to the marking of setts, such that attention to their location would not be obvious (i.e. signs should state ’ecological constraint’ or similar). This is additional mitigation distinct from the badger SPP. BD11: Temporary infrastructure (including site compounds, trackway, working platforms) and watercourse crossings will be micro-sited to avoid known or newly established resting sites of protected species, as per the SPPs. All resting sites of protected species will be retained as far as reasonably possible through micro-siting. Due to decisions on temporary infrastructure to be confirmed by the Principal Contractor(s), this additional mitigation is essential to secure as it allows for the avoidance of such protected resting sites which have not been covered during the surveys or hence accounted for in this assessment. BD12 Ground-based surveys of trees to be felled within areas of moderate or high suitability to support roosting bats will be undertaken prior to felling. Survey requirements of low suitability woodland prior to felling will be determined by the ECoW. Where potential roost features are identified in any tree subject to felling, an inspection of the potential roost features by an NatureScot - licensed bat surveyor will be undertaken in line with BCT guidelines36 (aided by aerial rope access if necessary). Further inspections to fully categorise if a roost is present (or likely absent) may be required at the discretion of the NatureScot -licensed bat surveyor. These inspections will also identify any licensing and mitigation requirements for bats, such as the precautionary working methods and provision of compensatory roost features (i.e. bat boxes). This additional mitigation is highlighted as it is anticipated to merit a key planning condition.
BD13: Pre-construction surveys for nesting birds will seek to identify the locations of any active nests within, or immediately adjacent to the working and felling areas along the OHL Route. All pre- construction bird surveys should extend a sufficient distance out from the OHL Route to identify any nest sites which may be within the disturbance range of the species in question. For example, pre- construction checks for general nesting birds should not need to extend out beyond 50 m, while surveys for declining waders may need to extend out to at least 200 m and surveys for rare and vulnerable raptors out to at least 500 m.
7-39 BD14: For rare and vulnerable breeding raptors, surveys will be conducted in areas of potentially suitable habitat in the year prior to works being undertaken in order to gauge the likelihood of such species posing a constraint. In the unlikely event that any identified nest sites may need to be removed to facilitate works (e.g. on steel lattice towers or woodland felling to increase the width of the operational corridor), then this could be done in the intervening non-breeding season so that the risk of constraint during the works is much reduced. The removal of rare and vulnerable breeding raptor nest sites would only be undertaken if absolutely necessary and in consultation with NatureScot, in accordance with the Bird SPP. It may also require the provision of an alternative artificial nest site (e.g. a nesting pole for ospreys). During the year of works, surveys for rare and vulnerable breeding raptors will also be undertaken well ahead of works advancing into each section of the OHL Route so that any new nest sites are identified early and appropriate mitigation measures can be applied. BD15: In the event that any confirmed, or suspected active nests are identified within or in close proximity to the works (i.e. within range of potential disturbance), then a works exclusion zone will be established around the nest site to a distance commensurate with the disturbance range of the species concerned which will be advised upon by the ECoW. Works will not be permitted to commence within the exclusion zone until nesting has been completed and the young have fledged, or the ECoW deems, through monitoring and stage of the breeding attempt, that the extent of the exclusion zone may be reduced. Based on records received during the consultation exercise, it is known that the nest sites of some rare and vulnerable breeding raptors exist near the OHL Route (see Appendix 7.5: Confidential Bird Data). Assuming they are active in the year of the works, it is likely that construction activities in proximity to these locations will need to be postponed until at least mid to late August once any young have fledged and nesting is concluded. BD16: With regards to measures to avoid potential disturbance of greylag geese associated with Hare Myre, Monk Myre and Stormont Loch SSSI, all construction works within 1 km of the designated site in October, when substantial number of the migratory geese are expected to be present, will be limited to the period one hour after sunrise to one hour before sunset. BD19: In the absence of a published Beaver SPP, the following mitigation measures specific to beaver will be adhered to. Pre-construction surveys for beavers will be undertaken following relevant best practice, alongside other pre-construction ecology surveys. The mitigation hierarchy will be applied to avoid and preserve identified resting sites (including burrows and lodges) in the first instance. Works will primarily maintain a 30 m buffer around identified resting sites to avoid / reduce potential disturbance impacts. Where this exclusion zone cannot be maintained, or a feature must unavoidably be destroyed as a last resort, NatureScot will be consulted regards to the requirements for a licence.
Monitoring BD7: Construction phase monitoring would be carried out by the ECoW, to ensure compliance with environmental legislation and effective delivery of mitigation measures (and licence conditions) set out in the generic and works-specific SPPs. Monitoring requirements beyond the construction phase would be identified through specific SPPs associated with discrete licences permitting works affecting protected species resting sites.
7-40 Residual Effect
The residual effects associated with loss of, obstruction of or disturbance to bat roosts valued at the Local level, would be of low spatial magnitude based on the percentage of woodland of moderate and high suitability; and short-term. Compensatory roosts may take up to five years to become occupied, if at all. However local populations of bats are likely to use multiple other opportunities for roosting based upon their roost switching behaviour35 such that the loss of a single roost site may be of reduced effect (depending on the type of roost). Based on the successful application of mitigation measures, the residual effect on bats is anticipated to be of Minor Adverse significance (i.e. not significant). The residual effects associated with loss of, obstruction of or disturbance to other species identified as sensitive receptors (and their resting sites), which are valued at the Local level (badger, otter, beaver, water vole, and fish) and County level (pine marten and red squirrel) would be of low spatial magnitude and short-term duration. Ultimately therefore, residual effects would be of Minor Adverse significance (i.e. not significant). This assessment is made with probable confidence; whilst there is a lack of data on known bat roosts which would be affected by felling or survey data for the entire length of the OHL Route, the proposed mitigation measures are robust and impacts to discrete resting sites would be managed through licensing. Through the implementation of pre-construction surveys and checks, the residual effects on breeding birds through nest damage / destruction or disturbance are anticipated to be of Negligible significance (i.e. not significant). By restricting construction works within 1 km of Hare Myre, Monk Myre and Stormont Loch SSSI in October to between one hour after sunrise and one hour before sunset, any adverse effects on associated greylag geese are anticipated to be reduced to Negligible significance / none (i.e. not significant).
Cumulative Effects Nearby developments, including those associated with the reinforcement of the transmission network and other mixed developments within 5 km of the OHL Route, are identified in Chapter 5 and on Figure 5.1: Cumulative Developments. Due to the proximity of the majority of these projects to the Proposed Development, cumulative spatial effects are essentially the same as those predicted for the Proposed Development alone. Further, the Proposed Development will be undertaken in temporary sections. The only designated site with other nearby developments is the River Tay SAC, with a number of residential and mixed-use developments which have been approved. The Proposed Development will be of short-term temporal impact relative to these other permanent developments, such that cumulative effects would not be greater than that identified and mitigated for. If all projects proceed at different times there is a potential for prolonging the period of disturbance to some receptors and increasing the recovery time of restored soils, agriculture and habitats. Given the non-significant nature of such effects once mitigation is applied, no significantly adverse cumulative or in combination effects are predicted to occur.
7.6 Summary The following sensitive biodiversity receptors (IEFs) along the OHL Route have been identified: · Designated sites – Pitkeathly Mires SAC / SSSI, River Tay SAC, River Dee SAC / LNCS, River South Esk SAC; Devon Gorge SSSI, Gannochy Gorge SSSI, Hare Myre, Monk Myre and Stormont Loch SSSI; Strathifinella LNCS, Loch of Park LNCS, Candyglirach LNCS;
7-41 · Habitats – running water, ancient woodland, non-designated broadleaved and mixed woodland, heath; and · Species – badger, otter, beaver, water vole, bats, pine marten, red squirrel, fish, rare and vulnerable breeding raptors, declining breeding waders.
This chapter has considered how, in the absence of mitigation, the Proposed Development would affect the above IEF by habitat loss, degradation and fragmentation; species mortality and injury; and loss of, obstruction of, or disturbance to species and their resting sites during the construction phase. Through successful application of embedded and industry-standard mitigations (including GEMPs and SPPs), and additional (secondary) mitigations identified through the EcIA which are summarised in Table 7-7-9; this chapter concludes that the Proposed Development would not result in a residual significant effect on any sensitive biodiversity receptors.
Table 7-7-9 Summary of additional biodiversity mitigations
Ref. Mitigation
BD1 Only areas of woodland (including designated and non-designated) that are identified as requiring essential, unavoidable felling will be subject to felling. Wherever possible, woodland will be retained. BD2 Pitkeathly Mires SAC Method Statement will be adhered to (included in Volume 4 Appendix 7.3: Pitkeathly Mires National Vegetation Classification Survey Report). BD3 Consent for works within Devon Gorge SSSI and Pitkeathly Mires SSSI will be sought from NatureScot prior to commencement of works. BD4 There will be no site compounds located within 50 m of designated sites. There will be no refuelling activities within 50 m of designated sites. BD5 Dry-stone walls and boundary features will be dismantled by hand between April and October (inclusive) (i.e. during the reptile and amphibian activity season) and in favourable weather conditions and then reinstated upon completion of works. BD6 A portion of felled tree stems and limbs will be retained in piles within the operational corridor (subject to landowner agreement) to increase connectivity for small mammals, create habitat resources for invertebrates, reptiles and amphibians, and in turn provide new foraging opportunities for protected species such as badger, pine marten and bats. BD7 The ECoW will provide on-site guidance. Specifically, this will extend to advising on practices set out in the CEMP, GEMPs, generic and work-specific SPPs, and method statements to minimise: habitat loss, habitat degradation, disturbance to protected species, spread of invasive non-native species. The ECoW will monitor any pollution events and advise on the requirement for spill kits or other reactive measures. The ECoW will advise on specific conditions associated with licences and consents, ensuring these are met prior to and during works. ECoW presence will be full-time during works through SACs and SSSIs. The ECoW will deliver pre-construction inductions to all site workers on species likely to be encountered, known resting sites in the works area, and controls in the relevant GEMPs and SPPs which will avoid reckless killing of, or injury to protected species. BD8 Invasive non-native species will be demarcated by the ECoW. No works will occur within 7 m of identified invasive non-native species to prevent further spread. BD9 Pre-construction surveys for badger, otter, water vole, pine marten and red squirrel will be undertaken to identify the current use of known and newly established resting sites along the whole of the OHL Route. Pre-construction survey requirements are set out in the existing SPPs, which state the validity period of survey data for most species as 12 months. This additional mitigation is raised to highlight the essential requirement that pre-construction survey be undertaken due to the lapse in time between baseline assessments and construction, as well as because baseline surveys did not cover the entire OHL Route. These surveys will also identify any protected species licencing requirements, including the potential to close / remove existing resting sites and provide alternative, artificial shelters. It is anticipated that this will merit a planning condition. BD10 Exclusion zones in which no works (including felling) will take place will be established around all badger setts along the OHL Route and proposed access routes, which will be physically marked out prior to commencement of works. The minimum buffer around entrances of setts in current use will be 20 m for felling activities and 30 m for all other works. Consideration should be given to the
7-42 Ref. Mitigation marking of setts, such that attention to their location would not be obvious (i.e. signs should state ’ecological constraint’ or similar). This is additional mitigation distinct from the Badger SPP. BD11 Temporary infrastructure (including site compounds, trackway, working platforms) and watercourse crossings will be micro-sited to avoid the known or newly established resting sites of protected species. All resting sites of protected species will be retained as far as reasonably possible through micro-siting. BD12 Ground-based surveys of trees to be felled within areas of moderate or high suitability to support roosting bats will be undertaken prior to felling. Survey requirements of low suitability woodland will be determined by the ECoW. Where potential roost features are identified in any tree subject to felling, an inspection of the potential roost features by an NatureScot-licensed bat surveyor will be undertaken in line with BCT guidelines36 (aided by aerial rope access if necessary). Further inspections to fully categorise if a roost is present (or likely absent) may be required at the discretion of the NatureScot licensed bat surveyor. These inspections will also identify any licensing and mitigation requirements for bats, such as the precautionary working methods and provision of compensatory roost features (i.e. bat boxes). This additional mitigation is highlighted as it is anticipated to merit a key planning condition. BD13 Pre-construction survey for nesting birds will be undertaken to identify the locations of any active nests within, or immediately adjacent to the working and felling areas along the OHL Route. All pre- construction bird surveys should extend a sufficient distance out from the OHL Route to identify any nest sites which may be within the disturbance range of the species in question (e.g. approximately 50 m for general nesting birds, at least 200 m for declining waders, and at least at least 500 m for rare and vulnerable raptors). BD14 For rare and vulnerable breeding raptors, surveys will be undertaken in areas of potentially suitable habitat in the year prior to works being undertaken in order to gauge the likelihood of such species posing a constraint. In the unlikely event that any identified nest sites may need to be removed to facilitate works then this could be done in the intervening non-breeding season so that the risk of constraint during the works is much reduced. The removal of rare and vulnerable breeding raptor nest sites would only be undertaken if absolutely necessary and in consultation with NatureScot, in accordance with the Bird SPP. It may also require the provision of an alternative artificial nest site (e.g. a nesting pole for ospreys). During the year of works, surveys for rare and vulnerable breeding raptors will also be undertaken well ahead of works advancing into each section of the OHL Route so that any new nest sites are identified early and appropriate mitigation measures (as detailed above) can be applied. BD15 In the event that any confirmed, or suspected active nests are identified within or in close proximity to the works, then a works exclusion zone will be established around the nest site to a distance commensurate with the disturbance range of the species concerned which will be advised upon by the ECoW. Works will not be permitted to commence within the exclusion zone until nesting has been completed and the young have fledged, or the ECoW deems, through monitoring and stage of the breeding attempt, that the extent of the exclusion zone may be reduced. BD16 All construction works taking place within 1 km of Hare Myre, Monk Myre and Stormont Loch SSSI in October will be restricted to the period between one hour after sunrise to one hour before sunset in order to avoid potential disturbance of associated roosting greylag geese when substantial numbers are expected to be present. BD17 The loss of woodland habitat through permanent forestry loss to widen the operational corridor either side of the OHL Route will be off-set through off site compensatory planting. While the location(s) of the compensatory planting are not currently known, the trees selected for this planting will be native species of local provenance. The species mix and planting regime (including planting density, protection measures and establishment monitoring) will be set out in a Compensatory Planting Plan. The compensatory planting excludes felling which would be within the existing 275 kV OHL operational corridor for which consent is already in place to manage trees for operational safety. BD18 All temporary masts with guy cable supports located in ornithologically sensitive areas, such as areas of known raptor activity based on data presented in Appendices 7.4 and 7.5 and pre- construction surveys will be fitted with bird diverters to increase their visibility to birds and thereby reduce the risk of collision. BD19 Pre-construction surveys for beavers will be undertaken following relevant best practice, alongside other pre-construction ecology surveys. The mitigation hierarchy will be applied to avoid and preserve identified resting sites (including burrows and lodges) in the first instance. Works will primarily maintain a 30 m buffer around identified resting sites to avoid / reduce potential disturbance impacts. Where this exclusion zone cannot be maintained, or a feature must
7-43 Ref. Mitigation unavoidably be destroyed as a last resort, NatureScot will be consulted regards to the requirements for a licence. It is anticipated that these mitigation measures will align with the SHE Transmission Beaver SPP (due to be published in early 2021).
Monitoring requirements beyond the construction phase would be identified through specific Species Protection Plans associated with discrete licences permitting works affecting protected species resting sites.
7-44 8 CULTURAL HERITAGE
8.1 Introduction This chapter assesses the potential effects on cultural heritage resulting from the Proposed Development. The chapter will describe and assess the cultural heritage baseline by identifying the cultural heritage resources within an appropriate study area around the Proposed Development. The cultural heritage resources consist of heritage assets that can include an individual building, monument, site, place, area or landscape identified as having a degree of significance because of its heritage interest. For the purposes of this assessment, heritage assets include World Heritage Sites, Scheduled Monuments, Listed Buildings, Gardens and Designed Landscapes (GDLs), Historic Battlefields, Conservation Areas, and other undesignated assets (buildings of historic or architectural importance, and any other known and previously unknown archaeological features).
The specific objectives of the chapter are to: · Describe the cultural heritage baseline; · Describe the assessment methodology and significance criteria used in the assessment; · Describe the value of known heritage assets and the magnitude of impact from the Proposed Development; · Describe the potential environmental effects, including direct and cumulative effects; · Describe the mitigation and, where appropriate, monitoring measures proposed to address likely significant effects; and · Assess the residual effects remaining following the implementation of mitigation.
Additional information which supports this chapter is presented in the following figures and technical appendices: · Figure 8.1: Heritage Assets; · Appendix 8.1: Cultural Heritage Gazetteer; and · Appendix 8.2: Assessment of Potential Impacts.
8.2 Assessment Methodology and Significance Criteria
Scope of the Assessment The assessment of cultural heritage focusses on the known heritage assets within the study area surrounding the Proposed Development, as well as identifying areas that have the potential to contain currently unknown archaeological remains. This chapter will define the known heritage assets and attempt to identify the likely types of archaeological remains that may be encountered, if existing, and will assess the impacts of the Proposed Development on the cultural heritage resource. The results of the baseline gathering exercise within the study area are shown within Appendix 8.1: Cultural Heritage Gazetteer, with all identified heritage asset locations depicted upon Figure 8.1: Heritage Assets.
8-1 Extent of the Study Area The locations of heritage assets along the OHL Route and within a 200 m study area surrounding it, as well as any heritage assets within a 50 m wide corridor around the indicative access routes, were collated to allow a determination of the potential impact on them from the Proposed Development. The study area was determined to allow a fuller characterisation of the potential direct impacts associated with the cultural heritage resource present along the OHL Route. The study area allowed for a wider, archaeological contextual background to be presented for the general area. The study of the surrounding landscape was necessary to establish the local archaeological and historical context, providing a broader understanding of the historical development along the OHL Route, and the potential for the discovery of as yet unidentified archaeological remains within those areas.
Consultation Undertaken to Date Consultation has taken place with a number of stakeholders. Summaries of the responses are highlighted in Table 8-1.
Table 8-8-1 – Consultation responses of relevance to Cultural Heritage
Organisation Type of Response How response has been Consultatio considered n Historic Scoping HES has confirmed that impacts on the setting The queries regarding Environment report of assets within their remit can be scoped out direct impacts on Fasque Scotland submission of further assessment. Estate GDL have been (HES) noted and the GDL has They also welcome the inclusion of assessing been included within the direct impacts on assets within their remit, and assessment for direct request further consultation relating to the impacts. works at Dalbog House, fields and cairns (SM4633). Mitigation has been included detailing the They would like further consultation regarding requirements for further the potential impacts on the Fasque Estate consultation with regards GDL as the Previous ES scoped in the to SM consent. assessment of impacts on the GDL. HES Additional HES has confirmed that impacts on the setting The response from HES tower of assets within their remit can be scoped out has been welcomed and extensions of further assessment. the assessment has scoping included all potential report HES consider that there is significant potential impacts on scheduled for direct impacts on scheduled monuments monuments within the given their proximity to the existing OHL and 50m or 100m buffers recommend avoidance in line with our around the towers to assumptions. assess the impacts.
HES note that East Memus, standing stone Mitigation has been 700m NE of (SM118), and Inverquharity, Roman recommended to avoid all fort, Roman camp and Iron Age settlement scheduled monuments 440m NE of (SM6452) are within 100m of where feasible. tower extensions and recommend avoidance and where this is not possible scheduled Mitigation has also been monument consent (SMC) will be required. included detailing the requirements for further consultation with regards to scheduled monument consent where avoidance is not possible.
8-2 Organisation Type of Response How response has been Consultatio considered n HES Gatecheck HES have reiterated their previous comments Mitigation has been Report regarding the East Memus, standing stone recommended to avoid all 700m NE of (SM118), and the Inverquharity, scheduled monuments Roman fort, Roman camp and Iron Age where feasible. settlement 440m NE of (SM6452). Mitigation has also been They also reiterated the need to assess impacts included detailing the on the Tippermuir Inventory Battlefield (BTL39) requirements for further and in particular Old Gallows Road. consultation with regards to scheduled monument consent where avoidance is not possible.
The assessment of the impacts on the Battlefied have followed HES guidance and mitigation to consult with Perth & Kinross Heritage Trust has been included for all works within the battlefield area. Aberdeenshire Scoping The Council are satisfied for the items noted The Gazetteer shows the Council report within the scoping report to be scoped in and reference numbers for submission out of the assessment. each Historic Environment Record (HER) and Figure Designations and Designated Sites should have 8.1 has been created to their local authority clearly marked within the differentiate between EIAR. This will aid with the assessment of the assets in different Council eventual submission. regions. Angus Scoping The Council are satisfied for the items noted Response noted. Council report within the scoping report to be scoped in and submission out of the assessment. Perth & Scoping The Council are satisfied with the conclusions Response noted. Kinross report of the report and have no further comments to Council submission make.
Method of Baseline Data Collation The assessment has been informed by the Previous ES as well as a review of all available archaeological records, historical documentary evidence, cartographic evidence, and photographic material. This has involved a review of the following data sources: · GIS data on World Heritage Sites, Scheduled Monuments and Listed Buildings obtained from HES; · GIS data on cultural heritage sites obtained from the Scottish National Record of the Historic Environment (SNRHE) which is maintained by HES; · Information from the Aberdeenshire and Angus Historic Environment Records (HER), both maintained by the Aberdeenshire Council Archaeology Service (ACAS); · Information from the Perth and Kinross HER maintained by the Perth and Kinross Heritage Trust (PKHT); · Readily accessible primary and secondary historical sources were consulted for information relating to the area’s historical past, including past land use; · Pre-Ordnance Survey maps of the Proposed Development area held by the National Library of Scotland (NLS). The relevant maps range in date from the seventeenth to the nineteenth centuries;
8-3 · First and subsequent editions of the Ordnance Survey Maps of the area of interest, held by the NLS; and · Solid and drift geology maps for the Proposed Development area, recorded by the British Geological Survey / Geological Survey of Great Britain maps.
The SNRHE and HER data were checked between the 22 June 2020 and 30 June 2020. Any additions or alterations to these records made after that date have not been included in this assessment. Information on World Heritage Sites, Scheduled Monuments, Listed Buildings, GDLs, and Historic Battlefields were downloaded from HES on 30 June 2020.
Site surveys of Towers 137-142, 236, 239, and 372 where the proposed access routes have the potential to directly impact upon known designated heritage assets was conducted on the 11th and 14th May, and 4th June 2020. Observations were made about the potential for direct impacts during construction from access to the towers.
Assessment Methodology The following national legislation, national policy / strategy and guidance forms the background against which the assessment has been made: · Ancient Monuments and Archaeological Areas Act 197967; · Planning (Listed Buildings and Conservation Areas (Scotland)) Act 199768; · Scotland’s National Planning Framework (2014)69; · Scottish Planning Policy (2014)70 paragraphs 135-151; · Historic Environment Policy for Scotland (HEPS) (2019)71; · Our Place in Time: The Historic Environment Strategy for Scotland (2014)72; · Managing Change in the Historic Environment – Historic Environment Scotland’s guidance note series73; · Planning Advice Note (PAN) 2/2011: Planning and Archaeology (2011)74; and · Town and Country Planning (Scotland) Act 199775.
The following local planning policies are relevant to the Proposed Development and have been considered in the production of the assessment. They are all in line with national planning policies which seek for development to avoid designated cultural heritage assets, and have a strong presumption in favour of preservation in situ of designated and undesignated cultural heritage sites. · Aberdeenshire Council Local Development Plan (2017) states that protecting and improving the historic environment is important to the distinctiveness and sense of place within Aberdeenshire. The two policies that set out the protection of cultural heritage assets are: Policy HE1 Protecting historic buildings, sites, and monuments; and Policy HE2 Protecting historic and cultural areas. · Angus Council Local Development Plan (2016) recognises the need to protect and enhance the area’s cultural heritage in order to protect these assets for current and future generations. Policy PV8 Built and cultural heritage provides more detail on the protection that should be afforded to national, regional and local cultural heritage sites.
67 UK Government (1979) Ancient Monuments and Archaeological Areas Act 68 UK Government (1997) Planning (Listed Buildings and Conservation Areas (Scotland) Act 1997. 69 Scottish Government (2014). Scotland’s Third National Planning Framework 70 Scottish Government (2014). Scottish Planning Policy 71 Historic Environment Scotland (2019). Historic Environment Policy for Scotland 72 Scottish Government (2014). Our Place in Time – The Historic Environment Strategy for Scotland 73 Historic Environment Scotland (various). Managing Change in the Historic Environment – Historic Environment Scotland’s guidance note series 74 Scottish Government (2011). Planning Advice Note (PAN) 2/2011: Planning and Archaeology 75 Town and Country Planning (Scotland) Act 1997 8-4 · Perth & Kinross Local Development Plan (2019) has a vision to celebrate and enhance its rich natural assets and cultural heritage and aims to protect all aspects of the historic environment through the following policies: o Policy 26: Scheduled Monuments and Archaeology; o Policy 27: Listed Buildings; o Policy 28: Conservation Areas; o Policy 29: Gardens and Designed Landscapes; o Policy 30: Protection, Promotion and Interpretation of Historic Battlefields; and o Policy 31: Other Historic Environment Assets. In addition to compliance with national and local planning policy this assessment has been completed in accordance with the following professional standards and guidance: · Chartered Institute for Archaeologists (CIfA) Standard and Guidance for Historic Environment Desk-based Assessment76; · CIfA Code of Conduct77; and · CIfA Standards and Guidance for Consultancy Advice78.
Determining Magnitude of Change and Sensitivity of Receptors The assessment of the value (or sensitivity) of cultural heritage assets has involved consideration of how far the asset(s) contribute to an understanding of the past, through their individual or group qualities, either directly or potentially. These are professional judgements, but they are also guided by legislation, national policies, acknowledged standards, designation, criteria and priorities.
The tables below identify factors which are appropriate to consider during the assessment of cultural heritage assets, with the adoption of five ratings for value in relation to the heritage assets: very high, high, medium, low, and negligible. Table 8-2 sets out the criteria for assessing the value of assets.
Table 8-2: Criteria for Assessing the Value of Archaeological Assets
Value Example Very High World Heritage Sites (including nominated sites) Assets of acknowledged international importance High Scheduled Monuments (including proposed sites) Listed Buildings (Category A and B) Battlefields included within the Inventory Marine Protected Areas Gardens and Designed Landscapes Conservation areas containing nationally important buildings Undesignated assets of scheduled quality and importance Assets of national importance Medium Listed Buildings (Category C) Conservation areas containing buildings that contribute significantly to its historic character Assets of regional importance Low Assets of local importance
76 Chartered Institute for Archaeologists (2017), Standard and Guidance for Historic Environment Desk-based Assessment. 77 Chartered Institute for Archaeologists (2014a). Code of Conduct. 78 Chartered Institute for Archaeologists (2014b). Standards and Guidance for Consultancy Advice. 8-5 Value Example Assets compromised by poor preservation and / or poor survival of contextual associations Buildings of modest quality in their fabric or historical association Negligible Assets with very little or no surviving archaeological interest
The criteria for assessing the magnitude of impact from the Proposed Development on an asset is shown in Table 8-3.
Table 8-3: Factors in the Assessment of Magnitude of Impacts
Adverse Beneficial
Major Changes to most or all key archaeological Preservation of a Heritage Asset in situ where materials or key historic building elements such it would otherwise be completely or almost that the resource is totally altered. lost. Comprehensive changes to setting such as Changes that appreciably enhance the extreme visual effects, gross change of noise or cultural significance of a Heritage Asset and change to sound quality, or fundamental changes how it is understood, appreciated and to use or access. experienced.
Moderate Changes to many key archaeological materials or Changes to important elements of a Heritage key historic building elements, such that the Asset’s fabric or setting, resulting in its cultural resource is clearly modified. significance being preserved (where this Considerable changes to setting that affect the would otherwise be lost) or restored. character of the asset such as visual change to Changes that improve the way in which the many key aspects or views, noticeable differences heritage asset is understood, appreciated and in noise or sound quality, or considerable changes experienced. to use or access.
Minor Changes to key archaeological materials or key Changes that result in elements of a Heritage historic building elements, such that the asset is Asset’s fabric or setting detracting from its slightly altered. cultural significance being removed. Slight changes to setting such as slight visual Changes that result in a slight improvement in changes to few key aspects or views, limited the way a Heritage Asset is understood, changes to noise levels or sound quality, or slight appreciated and experienced. changes to use or access.
Negligible Very minor changes to archaeological materials, Very minor changes that result in elements of historic buildings elements, or setting. a Heritage Asset’s fabric or setting detracting Very minor changes to setting such as virtually from its cultural significance being removed. unchanged visual effects, very slight changes in Very minor changes that result in a slight noise levels or sound quality, or very slight improvement in the way a Heritage Asset is changes to use or access. understood, appreciated and experienced.
No Change Changes to fabric or setting that leave significance unchanged.
The matrix shown in Table 8-4 provides an overall significance of environmental effect to be established for each heritage asset based on the value of the heritage asset and the magnitude of impact. For the purpose of this assessment, environmental effects of Moderate or greater significance are considered to be potentially significant.
8-6 Table 8-4: Overall significance of Environmental Effect
Magnitude of Impact
No Change Negligible Minor Moderate Major
Moderate or Large or Very high Neutral Slight Very Large Large Very Large
Moderate or Moderate or Large or Value (or High Neutral Slight Slight Large Very Large sensitivity) of asset Neutral or Moderate or Medium Neutral Slight Moderate Slight Large
Neutral or Neutral or Slight or Low Neutral Slight Slight Slight Moderate
Neutral or Neutral or Negligible Neutral Neutral Slight Slight Slight
Limitations and Assumptions The main limitation to the assessment is the nature of the archaeological resource - buried and not visible - which means it can be difficult to predict the presence and likely significance of buried assets accurately, and consequently the impact upon them, based primarily on desk-based sources. The baseline information presented within this report only provides an initial indication of archaeological potential rather than a definitive list of all potential buried heritage assets. The full extent of the potential buried heritage resource cannot be known prior to site-specific archaeological field investigation. Notwithstanding this limitation, the methodology is robust, utilising reasonably available information, and conforms to the requirements of national guidance and planning policy. Typically, standard archaeological prospection and evaluation techniques are utilised to reduce the uncertainties inherent in any desk-based assessment, where appropriate, as part of an overall mitigation strategy. The baseline data has been gathered assuming that the need for upgrading of existing tracks or the need for the construction of temporary roads would be determined by the Principal Contractor. It has been assumed that access routes that are off existing roads may involve upgrades and protection that aim to minimise ground disturbance from vehicle access. Details of the methods to be employed for creation of temporary access tracks are provided within Chapter 3, Section 3.6. The Principal Contractor would also confirm the arrangements regarding site office, welfare and storage yard locations along the route. For these elements of the works that have the potential to cause direct impacts on known heritage assets, generic site avoidance mitigation measures are proposed. Where these elements of the work have the potential to cause direct impacts on currently unknown heritage assets, archaeological investigations and subsequent recording of any discoveries would be required. This assessment is based on the Proposed Development as presented at the time of compiling this section of the report.
8-7 8.3 Baseline Conditions
Introduction There are 402 known cultural heritage assets within the study area around the Proposed Development. The assets consist of 28 Scheduled Monuments, 13 Listed Buildings, four Gardens and Designed Landscapes, one Registered Battlefield, and 356 undesignated assets listed within the local HER or SNRHE. The location of the designated and undesignated assets which lie within the study area around the Proposed Development are tabled in the Gazetteer (Appendix 8.1) and indicated in Figure 8.1: Heritage Assets.
In addition to the known cultural heritage assets as recorded on the HER and SNRHE, as derived from chance finds and any past archaeological investigations that may have been carried out, the Proposed Development has potential for possible, previously unrecorded archaeological remains, dating from the prehistoric period onwards. Without site-specific archaeological field investigation, the presence, extent, nature, date and heritage significance of such remains is not known.
Historical Background The principal sites and features within the Study Areas are summarised in the context of a timeline of archaeological periods from Prehistoric through to Modern. The time periods discussed can be broadly divided as follows: · Prehistoric: o Palaeolithic 12,000 – 11,000 BCE79 o Mesolithic 11,000 – 4,100 BCE o Neolithic 4,100 – 2,500 BCE o Bronze Age 2,500 – 800 BCE o Iron Age 800 BCE – CE80 400 · Roman CE 77 – 211; · Pictish CE 297 – 900; · Medieval CE 400 – 1560; · Post-Medieval CE 1560 – 1900; and · Modern CE 1900 – Present Prehistoric The earliest Prehistoric inhabitants of Scotland only leave ephemeral traces of their lives within the archaeological record. The people of the Palaeolithic and Mesolithic periods were nomadic hunter gatherers and left little evidence for their existence, with most sites encountered related to flint scatters. The majority of known sites from this period come from coastal regions with the dominant influence for settlement during this period related to availability of resources. The location of the OHL Route along the eastern coast of Scotland, skirting the foothills of the Cairngorms and crossing through several river valleys including the River Dee, the River North Esk, the River South Esk, the River Tay, the River Almond, the River Earn, and the River Devon, makes it an ideal location for the possibility of encountering Mesolithic activity. Examples of potential activity from this period include the four flint scatter sites (Site 52, Site 53, Site 54 & Site 57).
79 BCE - Before Common Era 80 CE - Common Era 8-8 The Neolithic period in Scotland is identified through the development of more sedentary lifestyles and the growth of farming. The area containing the Proposed Development is some of the most fertile land within Scotland today, dominated by glacial till consisting of sands and gravels, and providing ideal locations for Prehistoric people to have settled. The most visible aspect of this period in the archaeological record are the ritual monuments such as stone circles, henge monuments, standing stones, burial cairns, and other prominent stone features. Within the study area there are approximately 28 sites of likely Neolithic origin, and several other find spots containing potential Neolithic artefacts. The designated examples include Gallowhill stone circle (SM5408) (Site 262), East Memus standing stone (SM118) (Site 164), Almondbank filling station cairn (SM2267) (Site 332), Mains of Huntingtower henge (SM3630) (Site 334), Herald Hill long barrow (SM7282) (Site 247), and the Newbigging cup and ring marked stone (SM1509) (Site 271). The sites from this period stretch the full length of the OHL Route with a large concentration around the west side of Perth, and provide an insight into the ceremonial activity from the Neolithic. However, evidence of settlement activity is scarce, with pit clusters and rare finds of Neolithic pottery or stone tools being the only evidence of domestic activity during the period81. One example of potential Neolithic settlement and farming comes from a multi period site at Auchlishie (Site 183) where a possible Neolithic cultivation soil is cut by later Bronze Age pits, and Neolithic pottery was discovered within three pit features during the excavations. This cultivation soil and a potential Neolithic mound may have been removed by the erection of Tower 289, but it is likely that further sub-surface remains may be present in the surrounding area. There is a continuation of stone monuments in the Early Bronze Age, with stone circles and burial cairns overlapping the two periods. However, the burial practices change throughout the Bronze Age with cremation burials in decorated urns, and short cist internments becoming more prominent as time goes on. Examples of this type of burial practice within the study area include the cemetery at Kingoldrum (Site 202 & 206) where a number of short cists were discovered within the churchyard. Ten other possible cemetery or single burial locations are known within the study area including a cremation cemetery at Shanwell House (Site 386) where deposits of burnt bones and cinerary urns were discovered during gravel quarrying. Short cist burials including the deposition of food vessels, and the use of upturned urns for cremations are typical of Bronze Age burial traditions, with the majority of similar sites being from the Early Bronze Age82. In terms of settlement evidence for this period, cropmark evidence shows a large number of Prehistoric settlement locations, with some of the unenclosed and enclosed settlements likely attributable to the Bronze Age. One example of this is the potential palisaded enclosure at Gelvan (Site 389) where the thin cropmark enclosure has been interpreted as being a Prehistoric fence line, typical of the Late Bronze Age83. The later Prehistoric period of the Late Bronze Age and Iron Age is defined by an increase in archaeological visibility with a plethora of settlement sites identified through surveys conducted by aerial photography. As previously stated, the Proposed Development runs through some of the most fertile lands in Scotland, with the arable agricultural practices enabling the discovery of archaeological sites through these non-intrusive means. The most visible site type from these surveys are ring ditch houses, enclosed settlements, souterrains and other types of enclosure. Without further investigation of these sites it is not possible to provide exact dates for their origins, but it is likely that the majority of these settlement sites date from the Late Bronze Age, Iron Age and beyond.
81 Becket, A & MacGregor, G (2012) ‘Pit practices in Western Scotland in the 4th millennium BC’. In A. Anderson-Whymark & J. Thomas (eds) Regional Perspectives on Neolithic Pit Deposition: Beyond the Mundane Oxford: Oxbow Books 51-62 82 Stewart, M.E.C. and Barclay, G.J. (1997) ‘Excavations in burial and ceremonial sites of the Bronze Age in Tayside’ Tayside and Fife Archaeology Journal Volume 3 pp 22-54 [Online] Available at: http://www.tafac.org.uk/wp-content/uploads/2017/02/TAFAJ-Vol-3-2-Pt1-BA-excavations-in-Tayside-Stewart.pdf [Accessed 24/04/2020] 83 Hingley, R (1998) Settlement and Sacrifice: The Later Prehistoric People of Scotland Canongate Books, Edinburgh 8-9 Within the study area there are 23 sites of possible Late Bronze Age and Iron Age date, consisting of enclosures and probable ring ditch houses, with one designated example of this type of house known at Hallhole (SM7155) (Site 248). There are a further six sites thought to contain souterrains, which are typical elements of Iron Age settlements, and five Iron Age hillforts, with two of the most notable at the southern end of the study area: Castle Law Fort (SM661) (Site 372) and Law of Dumbuils Fort (SM9439) (Site 366). These forts are approximately 1.5 km apart, with Castle Law at the edge of the Ochil Hills, and Law of Dumbuils on the foothills to the north, with the forts likely having intervisibility if they were in use at the same time. Roman The Roman Period in Scotland is a short-lived period of occupation that was mainly concentrated in southern Scotland, the central belt and areas south of the Antonine Wall. In Perthshire, Angus, and Aberdeenshire there are traces of Roman activity from the early campaigns beyond the Forth, with an example within the study area the Roman fort and temporary camp at Inverquharity (SM6452) (Site 173). There are also traces of Roman activity from findspots at Auchlishie (Site 183) and Kingoldrum (Site 205) indicating probable trade between the Romans and the Iron Age people in the areas. Furthermore, possible Roman Roads are known to the north of Perth and one of the main lines of Roman activity is to the south and west of Perth, along the Gask Ridge where a line of forts, fortlets and watchtowers stretch between Dunblane and Perth. One of these watchtowers is within the study area at Huntingtower (Site 335), which is the easternmost watchtower along this line.
Early Medieval / Pictish Throughout the Roman period and into the Early Medieval period, the local inhabitants would have continued to populate the many settlements along the OHL Route, with the Pictish people cited by the Romans, being the ancestors of the Iron Age inhabitants occupying the lands along the eastern coast of Scotland. The village of Abernethy is situated approximately 8 km to the west of the OHL Route and is known as the capital of the Pictish Kingdom, and several pieces of Pictish or Early Medieval carvings are known from the village. The Pictish influence throughout the Medieval period is not restricted to the areas around Perth, but also reaches into the northern parts of Scotland. In relation to the study area, the most visible Pictish sites are the funerary monuments known as square barrows. Three such sites are known within the study area, one of which is the scheduled Hallhole square barrow and pit alignment (SM6933) (Site 252), comprising a circular mound surrounded by roughly square ditches and banks.
Medieval In the histories related to Early Medieval Scotland there is a far greater sense of sovereign and religious control and influence within the country than is discussed in the Iron Age and earlier periods. The construction of Iona Abbey in the 6th century heralds the era of Christian influence within Scotland, and the unification of the country into a single kingdom in the 9th century brings greater political control. From this period, the archaeological record shows the development of local religious centres and seats of power. Along the OHL Route there are four known chapels that date to the Medieval period. The most influential of these is the Coupar Grange (SM7327) (Site 239), which was established in the 12th century and would have been a focal point for local people to settle.
8-10 The other focal point for settlement would have been the existence of political centres, with local lords creating moated settlements like the one at Hallyards (SM7262) (Site 232) or castles such as the one at Inverquharity (Site 170). As the OHL Route avoids population centres, there are few of these religious and political focal points along the route. However, there are early rural houses such as the example at Dalbog House (SM4633) (Site 124) consisting of a single house within a cairnfield and field system. There are also several other sites containing Medieval rig and furrow cultivation remains, along with associated field boundaries, most of which have been discovered by aerial photography. Furthermore, the early town lades (Site 324) that powered the mills of Perth are located within the study area to the west of Perth, providing evidence related to the industrialisation that would lead to a revolution in the centuries to follow.
Post-Medieval The rural farming practices evident within the study area during the Medieval period continue to flourish into the Post-Medieval period, with around 90 farmsteads and crofts noted within the study area, along with several other vernacular buildings related to agricultural practices, several sites of rig and furrow cultivation, and associated field boundaries and marker stones. The industrialisation of the area is not as prevalent as in the towns and villages but there are still mills, limekilns, quarries, and other small-scale industries within the study area that show a level of industrialisation that reached the rural areas. A focus of this industrialisation is evident within the study area around Blairingone, where a colliery (Site 400), tile works (Site 398), and lime works (Site 397) were all located, making use of the nearby Alloa to Kinross railway line (Site 396). The biggest change to the rural areas would have come from the political unrest related to the Jacobite rebellion in the 18th century that was a catalyst for the expansion of the local towns and villages, with communities encouraged and coerced to move away from the small farming settlements. The rebellion also brought the introduction of the military roads and the railway line in the 19th century increased the potential for industrialisation. Large numbers of the farmsteads and crofts within the study area were depopulated by the end of the 19th century, but in contrast there is a marked increase in the number of large estate houses being constructed by the people able to exploit the industrial expansion. The most notable of these new houses within the study area are now contained within Garden and Designed Landscapes and include Fasque House (GDL00178) (Site 108), Cortachy Castle (GDL00108) (Site 176), and The Burn (GDL00355) (Site 127). These houses and their landscaped gardens were all created between the 18th and 19th centuries, making use of the lands previously used for small crofts. One site of national importance within the study area from the Post-Medieval period, that contains elements of the OHL Route, is the Registered Battlefield of the Battle of Tippermuir (BTL39) (Site 344), where the Covenanter army was routed by the Royalist army in 1644. The battlefield is on the western edge of Perth and a number of significant landscape elements, and the former road through the area (Site 341) that was used by the Royalists is still in situ.
Modern In the 20th century, new cultural heritage assets within the study area include further industrial and agricultural structures and works, along with World War II tank ditches (Site 292), and an anti-aircraft battery (Site 353). The Bertha Park High School (Site 320) is the only asset from the 21st century within the study area.
8-11 Archaeological Potential
With so much evidence of subsurface archaeological remains from cropmark sites it would be expected that the study area would contain other more ephemeral sites. Also, due to the large number of known heritage assets along the OHL Route, and given the length of the Proposed Development and its location within a mainly rural area that has undergone little modern development, the potential for the study area containing as yet unknown heritage assets is high.
Future Baseline The current baseline as described below will continue to evolve without the introduction of the Proposed Development. As the OHL Route sits within a mainly rural landscape, a combination of agricultural practices and natural processes may lead to the deterioration of above and below ground archaeological remains. It is also likely that future development and assessment related to cultural heritage along the OHL Route will encounter further heritage assets through continued programmes of aerial photography, as well as discoveries from intrusive archaeological investigations.
Sensitive Receptors It is considered that only those assets within a relatively close proximity to the Proposed Development may potentially receive significant effects from direct physical impacts. As such, detailed assessments have been undertaken for designated and undesignated cultural heritage assets within 50 m of the majority of the tower locations, 100 m of the towers due to be extended, as well as within a 50 m corridor centred on the proposed access routes (Appendix 8.2: Assessment of Potential Impacts).
8.4 Issues Scoped Out The potential for direct and indirect impacts during construction and operation of the Proposed Development on World Heritage Sites, Marine Protected Areas and Conservation Areas has been scoped out of the cultural heritage assessment as there are none which cross the OHL Route or are located within the 200 m study area or the 50 m corridor around proposed access routes. All indirect impacts on the setting of designated and undesignated assets from the operation of the Proposed Development have been scoped out as the Proposed Development will not introduce any new, significant elements of infrastructure, with the current towers being retained and only minimal extensions on 73 towers.
Assessment of impacts to Listed Buildings has been be scoped out as there will be no direct or indirect impacts on any Listed Buildings. It is anticipated that access through Fasque Estate GDL (GDL00178) will not require upgrades or alterations to the current road network but the impacts will be assessed in line with HES recommendations. It is also assumed that all temporary access roads and tracks constructed outside of existing roads and tracks will be removed at the completion of the project.
8.5 Assessment of Effects, Mitigation and Residual Effects
Mitigation by Design Cultural heritage assets, including archaeological remains, are a finite resource and therefore non- renewable. The preferred option for the mitigation of archaeological remains during the design of the Proposed Development is preservation in situ. However, this is not always possible, and in these instances preservation by record will allow the remains to be fully investigated and recorded prior to construction, mitigating any adverse impacts. The results of these investigations can then be included in a report and disseminated to the local HER to provide a permanent record of the archaeological works.
8-12 Embedded mitigation is integral to the design. Relevant embedded mitigation to Cultural Heritage includes avoidance of new tower construction as the Proposed Development will upgrade the existing towers as set out in Chapter 2. The works will also make use of access tracks previously used for the earthwire replacement works and the Applicant’s maintenance teams wherever possible, as described in Chapter 3. Furthermore, all construction activities have been designed to be as low impact as possible in order to minimise any direct impacts on potential unknown, subsurface heritage assets.
Construction Phase Design Solutions and Assumptions The current design of the works required to undertake the Proposed Development is yet to be finalised, but it has been assumed there is flexibility in access route location and positioning of other necessary infrastructure. It is assumed that all efforts have been made to avoid impacting upon designated cultural heritage assets such as Scheduled Monuments, Listed Buildings, Gardens and Designed Landscapes, and Registered Battlefields. Where the current design has the potential to impact upon such assets, specific mitigation is provided to ensure avoidance of these assets, where this is possible.
It is also assumed that where existing tracks are being used for access, they will be used with only minor modifications and patching. It can then be anticipated that the adjacent cultural heritage assets would not experience any impacts. Impacts, potentially leading to significant effects are possible where a need to upgrade tracks within or adjacent to cultural heritage asset areas is identified, but such information is not available for all tower locations at this stage. Where tower extensions are required (Table 3-1), it is assumed there will be a need for stone access to be provided for the heavy machinery to be used, which will follow the methodology set out in Chapter 3 Section 3.6, ensuring minimal ground disturbance. The temporary towers and / or masts to be erected at these towers to allow line diversions require a larger working area that may be up to 100 m from the existing tower, and are erected using construction techniques as set out in Chapter 3 Section 3.6. All diversions will be designed to avoid environmental constraints where possible. Description of Effects
All impacts upon the cultural heritage resource will occur during the construction phase. Development activities including, but not limited to groundworks, topsoil stripping, landscaping, ground compaction, access, drainage, stockpiling, and storage may all have a direct adverse effect on known and unknown cultural heritage assets. The construction related impacts could lead to the following effects: · Permanent complete or partial loss of a cultural heritage resource as a result of ground excavation; · Permanent or temporary loss of the physical integrity of a historic monument, historic group of buildings or historic site; · Damage to the cultural heritage resource as a result of ground excavation; · Damage to the cultural heritage resource due to compaction, desiccation or waterlogging; and · Damage to the cultural heritage resource as a result of ground vibration caused by construction. The table below (Table 8-5) presents a summary of the potential direct physical impacts that may occur on the known cultural heritage assets due to the Proposed Development. All heritage assets that fall within a 50 m corridor of the proposed access routes, and / or within a 50 m buffer of a tower, and / or within 100 m of a tower due to be extended, are listed below. A detailed assessment for each heritage asset is provided in Appendix 8.2: Assessment of Potential Impacts.
8-13 The magnitude of impact has been assessed prior to the implementation of an agreed programme of archaeological mitigation, and is based on the likelihood of works such as those described above, causing physical damage to the heritage asset. From the assessment conducted, there is potential that the Proposed Development may have direct physical impacts on 192 heritage assets. Assets shaded in blue highlight potentially significant effects of Moderate or above.
Table 8-5 – Potential Direct Impacts on Heritage Assets and Resulting Significance of Effect
Asset Number and Tower Number where impacts may Magnitude of Significance of Description occur Impact (prior to Effect Access route Within tower mitigation) buffer 1 – Building and Enclosure - 558 No Change Neutral 2 – Farmstead 557 & 558 - No Change Neutral 4 – Rig and Furrow - 555 Negligible Neutral 8 – Standing Stone - 549 No Change Neutral 9 – Farmstead 547 & 548 - No Change Neutral 11 – Farmstead 545 - No Change Neutral 534, 537, 538 & 13 – Farmstead - No Change Neutral 539 14 – Cottage 534, 537 & 538 - No Change Neutral 16 – Farmstead 534 - No Change Neutral 19 – Farmstead 534 - No Change Neutral 20 – Farmstead 531-533 - No Change Neutral 21 – Gravel Pit 530-533 - No Change Neutral 24 – Farmstead 526 - No Change Neutral 26 – Boundary Stone - 525 No Change Neutral 27 – Stone Ball - 524 No Change Neutral 28 – Farmstead 523 & 524 - No Change Neutral 29 – Standing Stones 524 524 Minor Neutral 30 - Building - 524 Minor Neutral 31 – Building 523 - No Change Neutral 32 – Farmstead 522 - No Change Neutral 37 – Building 520 & 521 - No Change Neutral 38 – Natural Outcrop - 520 No Change Neutral 39 – Building 516 - No Change Neutral 40 – Farmstead 515 - No Change Neutral 46 – Building 505 - No Change Neutral 47 – Buildings - 501 No Change Neutral 49 – Croft - 499 Minor Neutral 50 – Croft - 497 Negligible Neutral 53 – Lithic Scatter - 495 No Change Neutral 56 – Flint Scatter 494 - No Change Neutral 57 – Farmstead 492 - No Change Neutral 61 – Croft 466 - No Change Neutral 64 – Boundary Stone 456 - No Change Neutral 65 – Boundary Stone - 456 No Change Neutral 67 – Farmstead 450 & 451 - No Change Neutral 68 – Farmstead - 438 Negligible Neutral 71 – Farmstead 433 - No Change Neutral 72 – Sheepfold 431 - No Change Neutral 73 – Banks - 431 & 432 Negligible Neutral 75 – Field System 428-430 - No Change Neutral
8-14 Asset Number and Tower Number where impacts may Magnitude of Significance of Description occur Impact (prior to Effect Access route Within tower mitigation) buffer 79 – Field System 426 & 427 426 & 427 Negligible Neutral 80 – Boundary Stone - 425 Negligible Neutral 83 – Earthwork 421 - Negligible Neutral 85 – Hollow Way 419 420 & 421 Minor Slight 86 – Earthwork - 420 Negligible Neutral 88 – Earthwork 412-418 - Negligible Neutral 89 – Gravel Pit 407-409 - No Change Neutral 90 – Croft 407 408 Negligible Neutral 91 – Farmstead 404-406 - No Change Neutral 105 – Market Place 398-402 - No Change Neutral 108 – Fasque Estate (GDL) 393-397 - No Change Neutral 109 – Farmstead 390-392 - No Change Neutral 110 – Farmstead 387-389 - No Change Neutral 112 – Farmstead 385 & 386 - No Change Neutral 115 – House 380-382 - No Change Neutral 117 – Church and Burial 378 - No Change Neutral Ground 118 – Farmstead and Mill 375 & 376 - No Change Neutral 120 – Farmstead 374 - No Change Neutral 121 – Findspot 374 - No Change Neutral 124 –Cairns, Mounds, & 372 372 Moderate Large House (SM) 125 – Farmstead - 370 Minor Slight 128 – Croft 366-368 - Moderate Slight 131 – Rig and Furrow 361-365 363 & 364 Minor Slight 132 – Rig and Furrow 361-365 361-363 Minor Slight 133 – Structure 361-365 - No Change Neutral 134 – Farmstead 360 360 Minor Slight 135 – Farmstead 357-359 - No Change Neutral 137 – Linear Earthwork - 353 No Change Neutral 349, 350 & 353- 139 – Farmstead - No Change Neutral 356 140 – Church (Category C) 345 - No Change Neutral 141 – Farmstead 341 & 342 - No Change Neutral 143 – Rig and Furrow 335, 336 & 340 340 Negligible Neutral 144 – Farmstead - 338 No Change Neutral 145 – Farmstead 335 & 336 - No Change Neutral 151 – Farmstead 335 336 Negligible Neutral 153 – Farmstead - 334 Minor Slight 156 – Farmsteads with Rig 325-330 & 332 325-330 Negligible Neutral and Furrow 159 - Farmstead 316-320 - No Change Neutral 160 – House (Category B) 316-320 - No Change Neutral 164 – Standing stone (SM) - 307 Minor Slight 165 – Farmstead 305 & 306 - No Change Neutral 166 – Farmstead and Mill 303 & 304 - No Change Neutral 167 – Cropmarks 300 301 No Change Neutral
8-15 Asset Number and Tower Number where impacts may Magnitude of Significance of Description occur Impact (prior to Effect Access route Within tower mitigation) buffer 168 – Pit-defined 297 - No Change Neutral Enclosure 169 – Farmstead 297 - No Change Neutral 173 – Fort and Settlement - 294 No Change Neutral (SM) 175 - Cropmarks 294 & 295 293 & 294 Negligible Neutral 176 – Cortachy Castle - 293, 295 & 296 No Change Neutral (GDL) 178 – Road and Bridge 293 - No Change Neutral 181 – Enclosed Settlement - 292 No Change Neutral (SM) 183 – Ring Ditches - 289 Minor Slight 184 – Ring Ditches 288 288 Minor Slight 186 – Settlement 286-287 - No Change Neutral 187 – Farmstead 283-286 - No Change Neutral 188 – Croft - 280 Negligible Neutral 191 – Rig and Furrow 279 & 280 278 & 279 Negligible Neutral 192 – Rig and Furrow 275-277 276 & 277 Negligible Neutral 194 – Rig and Furrow 275 275 Negligible Neutral 195 – Farmstead 274 - No Change Neutral 196 – Quarries 272 - No Change Neutral 203 – Church (Category C) 269 269 No Change Neutral 205 – Findspot - 269 No Change Neutral 206 – Cists - 269 No Change Neutral 209 – Enclosure 263 263 Minor Slight 214 – Souterrain and - 256 Negligible Neutral Cottage 215- Cropmark - 255 No Change Neutral 216 – Farmstead 254 & 255 - No Change Neutral 217 – Pits - 254 Minor Slight 219 – Cinerary Urn 253 - No Change Neutral 220 – Cropmarks 253 - No Change Neutral 225 – Rig and Furrow 241 241 Negligible Neutral 228 – Enclosure (SM) 239 239 Moderate Large 229 – Railway Bridge 238 - No Change Neutral 232 – Moated Settlement 237 236 Minor Slight (SM) 237 – Ring Ditch (SM) 220 - No Change Neutral 239 – Monastic Grange 219 - No Change Neutral (SM) 240 – Farmstead 218 - No Change Neutral 243 – Ring Ditches - 211 Negligible Neutral 244 – Farmstead 210 210 No Change Neutral 245 – Farmstead 209 - No Change Neutral 246 – Road 206-208 207 No Change Neutral 248 – Ring Ditch (SM) 205 - Moderate Large 249 – Pits and Enclosure 202-205 204 Minor Slight 251 – Settlement (SM) 203 - Minor Moderate
8-16 Asset Number and Tower Number where impacts may Magnitude of Significance of Description occur Impact (prior to Effect Access route Within tower mitigation) buffer 253 – Farmstead 202 - No Change Neutral 255 – Enclosure (SM) - 201 Minor Slight 256 – Farmstead 201 - No Change Neutral 260 – Railway 194-197 197 No Change Neutral 262 – Stone Circle (SM) 193 - Moderate Large 263 – Road - 191-193 Negligible Neutral 264 – Road 192 & 193 - Negligible Neutral 266 – Pictish Stone - 191 Minor Slight 267 – Spring and Human - 190 Minor Neutral Remains 271 – Cup and Ring 189 - No Change Neutral Marked Stone (SM) 273 – Farmstead 186 - No Change Neutral 274 – Road 187 - Negligible Neutral 278 – Standing Stones (SM) 181 - Moderate Large 283 – Stone Circle 176 & 177 - No Change Neutral 286 – Farmstead 173 - No Change Neutral 287 – Findspot 173 - No Change Neutral 292 – Tank Ditches 170 172 No Change Neutral 295 – Enclosure 164-166 - No Change Neutral 296 – Enclosure 166 166 Minor Slight 298 – Pits 163 163 Minor Slight 299 – Square Barrows 163 - No Change Neutral 300 – Enclosures and Pits 163 - No Change Neutral 304 – Roman Road - 161 Negligible Neutral 308 – Rig and Furrow 160 160 Negligible Neutral 309 – Field Boundary 160 160 Negligible Neutral 312 – Field Boundary 158 & 159 158 Negligible Neutral 313 – Standing Stone - 157 No Change Neutral 319 – Field Boundary 151-153 - No Change Neutral 321 – Rig and Furrow 151-153 - No Change Neutral 323 – Water Meadow 148 148 & 149 Negligible Neutral 324 – Lades - 146 & 147 No Change Neutral 326 – Mills - 147 No Change Neutral 327 – Chapel and Holy - 147 No Change Neutral Well 328 – Railway 145 & 147 146 Negligible Neutral 330 – Mill and Lade - 146 No Change Neutral 331 – Field Boundaries 146 146 Negligible Neutral 337 – Lodge (Category B) 141 & 142 - No Change Neutral 341 – Road 140 140 Minor Slight 344 – Battlefield 137-142 137-142 Minor Moderate 345 – Farmstead 139 - No Change Neutral 347 – Milestone 137 - No Change Neutral 349 – Farmstead 136 - No Change Neutral 351 – Farm Building 135 134 No Change Neutral 352 – Farmstead 128-131 - No Change Neutral 353 – Battery 128-131 - No Change Neutral
8-17 Asset Number and Tower Number where impacts may Magnitude of Significance of Description occur Impact (prior to Effect Access route Within tower mitigation) buffer 354 – Quarry 127 - No Change Neutral 355 – Bridge 126 - No Change Neutral 358 – Freeland Farm 121 & 122 - No Change Neutral 364 – Rig and Furrow - 117 Negligible Neutral 365 – Quarry 117 - No Change Neutral 367 – Farmstead 116 & 117 - No Change Neutral 369 – Farmstead 116 - No Change Neutral 370 – Hollow Way 112 & 113 - Negligible Neutral 377 – Rig and Furrow 110 & 111 - Negligible Neutral 379 – Settlement 105 - Minor Slight 381 – Farmstead 96 & 97 - No Change Neutral 382 – Farmstead 94 - No Change Neutral 383 – Village 84 - No Change Neutral 385 – Township 78 - No Change Neutral 386 – Cremation 74 - No Change Neutral Cemetery 388 – Pit Alignment 66 - No Change Neutral 389 – Enclosure 61-63 - No Change Neutral 390 – Settlement - 60 No Change Neutral 393 – Boundary Stone 54 - No Change Neutral 396 – Railway - 43 & 44 Negligible Neutral 398 – Tile Works - 43 Negligible Neutral 399 – Findspot 41-43 - No Change Neutral 400 – Blairingone Colliery 34 - No Change Neutral
Of the 192 known heritage assets that have the potential to be impacted upon, a total of 40 assets of negligible or low value have the potential to be impacted to a negligible or minor magnitude resulting in a Neutral significance of effect. Nineteen assets will have a Slight Adverse significance of effect due to potential minor magnitudes of impact on assets valued between Low and High. A single asset will have a Slight Adverse significance of effect due to a potential moderate magnitude of impact on an asset of Low value. It is anticipated that seven assets have the potential to experience significant impacts (Moderate or Large Adverse significance of effect) through direct impacts from the Proposed Development. The detailed assessment of these assets is provided below. The remaining 125 assets were considered to be unaffected by the Proposed Development. This is due to the asset either being recorded as destroyed, is a findspot with no physical remains, or there is no potential for the Proposed Development to impact upon the assets location i.e. it is an upstanding building in use, or the asset is within the access road buffer where there is no requirement for upgrades to the road or other construction activity.
8-18 Dalbog house, fields and cairns (SM4633) (Site 124)
The OHL Route passes over the Scheduled Monument of Dalbog house, fields and cairns, that lies within an arable field on the higher ground to the west of the River North Esk. The Proposed Development would require construction vehicles to enter and track through the scheduled area in order to access Tower 372, which is located within the curtilage of the monument. As there is no existing access track there is the potential for ground disturbance to occur as part of the access preparations. It is also likely that works may involve ground breaking and excavations around the existing tower base. The magnitude of impact from these works is anticipated to be moderate adverse on an asset of national significance and high value. Therefore, the overall significance of effect has been assessed as Large Adverse.
Haughend Enclosure (SM7263) (Site 228) The OHL Route passes over the Scheduled Monument of Haughend enclosure, which consists of cropmarks related to an enclosure, pit alignments and linear features. The site consists of a scheduled area comprising a rectangular area within arable fields, with an associated unscheduled area covering a larger portion of the fields to the south-east. The Proposed Development in its current form may require construction vehicles to enter and track through the scheduled area in order to access Tower 239. The tower is on the south-west edge of the curtilage of the scheduled area, but lies within the site boundary. As there is no existing access track there is the potential for ground disturbance to occur during access preparations. It is also likely that works may involve the ground breaking and excavations around the tower base. The likely magnitude of impact from these works is anticipated to be moderate adverse on an asset of national significance and high value. Therefore, the overall significance of effect has been assessed as Large Adverse.
Hallhole Ring Ditch (SM7155) (Site 248) The Scheduled Monument of Hallhole ring ditch lies approximately 300 m north-west of the OHL Route, and is situated within an arable field on the southern edge of a small area of woodland. The Proposed Development works in their current form may require construction vehicles to enter and track through the scheduled area in order to access Tower 205, which lies a few hundred metres to the west. As there is no existing access track there is the potential for ground disturbance within the curtilage of the scheduled area during access preparations. The likely magnitude of impact from these works is anticipated to be moderate adverse on an asset of national significance and high value. Therefore, the overall significance of effect has been assessed as Large Adverse.
Hallhole enclosures and trackways (SM7023) (Site 251) The Scheduled Monument of Hallhole enclosures and trackways lies approximately 200 m north- west of the OHL Route, and is situated in the corner of an arable field. The Proposed Development works in their current form may require construction vehicles to enter and track through the western corner of the scheduled area in order to access Tower 203. As there is no existing access track there is the potential for ground disturbance within the curtilage of the scheduled area during access preparations. The likely magnitude of impact from these works is anticipated to be minor adverse on an asset of national significance and high value. Therefore, the overall significance of effect has been assessed as Moderate Adverse.
8-19 Gallowhill Stone Circle (SM5408) (Site 262)
The Scheduled Monument of Gallowhill Stone Circle lies approximately 200 m south-east of the OHL Route, set within an area of woodland at the south-east corner of a pastoral field. The Proposed Development works in their current form may require construction vehicles to enter and track through the scheduled area in order to access Tower 193. As there is no existing access track there is the potential for ground disturbance to occur within the curtilage of the scheduled area during access preparations. The likely magnitude of impact from these works is anticipated to be moderate adverse on an asset of national significance and high value. Therefore, the overall significance of effect has been assessed as Large Adverse.
Loanhead Standing Stones (SM7298) (Site 278)
The Scheduled Monument of Loanhead standing stones lies approximately 220 m east of the OHL Route, set within a linear area of woodland dividing the arable fields on either side. The Proposed Development works in their current form may require construction vehicles to enter and track through the scheduled area in order to access Tower 181. As there is no existing access track there is the potential for ground disturbance to occur within the curtilage of the scheduled area during access preparations. The likely magnitude of impact from these works is anticipated to be moderate adverse on an asset of national significance and high value. Therefore, the overall significance of effect has been assessed as Large Adverse.
Battle of Tippermuir Registered Battlefield (BTL39) (Site 344)
The OHL Route passes through the Registered Battlefield of the Battle of Tippermuir, which is bounded by the A9 to the south and east, and includes the settlement of Tibbermore. The Proposed Development works in their current form may require vehicles to enter and track through the battlefield in order to access Towers 137-142. Some elements of the access tracks within the battlefield will use existing tracks, but there are a number of sections where access tracks do not exist. Furthermore, Tower 140 lies to the immediate north of a key element of the Battlefield, Old Gallows Road, and access to the tower uses this former road. Where there are no existing access tracks there is the potential for ground disturbance to facilitate access, and there is also the potential for upgrades to be required along Old Gallows Road. Any works around the tower bases may also involve ground breaking and excavation. The likely magnitude of impact from these works is anticipated to be minor adverse on an asset of national significance and high value. Therefore, the overall significance of effect has been assessed as Moderate Adverse.
Effects on potential heritage assets As well as the potential effects on known heritage assets, there is also the potential for direct impacts on currently unknown, subsurface archaeological remains. Any impacts on these potential assets would be the result of ground-breaking activities related to any temporary works required around the towers. The significance of effect on any archaeological remains encountered would be assessed as Moderate Adverse due to the required excavation of the assets to preserve them by record. Mitigation During Construction To mitigate the identified physical impacts to known cultural heritage assets shown in Table 8-5, a programme of archaeological works will be implemented in consultation with HES, ACAS, and PKHT. A summary of the proposed mitigation is presented in Table 8-6 below. The Principal Contractor will develop a Construction Environmental Management Plan (CEMP) post consent which will detail the below mitigation and any further mitigation.
8-20 Table 8-6 – Cultural Heritage Mitigation
ID Description
CH1 Further consultation will be required with HES with regards to any potential direct impacts on Designated assets, with the potential for Scheduled Monument Consent required. All designated heritage assets listed within Table 8-5 will be demarcated prior to site works for the Proposed Development to ensure that all access and other works avoid impacting upon these assets. Where such impacts cannot be avoided at Dalbog house (Site 124) and the Battle of Tippermuir Battlefield (Site 344), specific mitigation to reduce the impacts is suggested (see mitigation items CH6 and CH7).
CH2 All undesignated heritage assets with surviving upstanding remains or accurately known locations listed within Table 8-5 will be demarcated prior to site works for the Proposed Development to reduce the impacts on these assets where possible. Where heritage assets cannot be avoided, the recommendations provided by mitigation item CH4 will be followed.
CH3 Where the Proposed Development requires works over potential sub-surface remains of known heritage assets or any previously undisturbed ground, temporary surfaces such as protective matting will be used to minimise ground disturbance. Where ground breaking works are required in previously undeveloped ground, or over potential subsurface remains of known heritage assets, an archaeological watching brief will be undertaken. It is anticipated this would include, but not be limited to, the monitoring of ground breaking works for access tracks where there are no existing roads and any temporary works around the towers. The watching brief would allow for the recording of any known or potentially unknown archaeological remains and will be conducted according to a Written Scheme of Investigation (WSI) that has been agreed with ACAS and PKHT.
CH4 Where known archaeological assets cannot be avoided and will be directly impacted upon by the Proposed Development, a programme of archaeological works will be required that is likely to involve earthwork surveys and archaeological excavations conducted prior to construction. These works would aim to preserve the impacted heritage asset by record. Any archaeological works will be conducted according to a WSI that has been agreed with ACAS and PKHT.
CH5 The Contractor will consult with ACAS or PKHT, and HES where relevant, should any discoveries of heritage interest be made during construction, to enable appropriate measures to be implemented to mitigate potential impacts.
CH6 For access and works at Dalbog House (Site 124) the following mitigation has previously been agreed with HES: · An access route and working area around Tower 372 will be marked out in agreement with HES, to minimise the impact on upstanding remains; · Temporary surfaces such as matting will be used to minimise ground disturbance; and · A detailed statement of working methods and mitigation measures will be developed and attached to an application for Scheduled Monument Consent to be made to Scottish Ministers at an appropriate time to allow the reconductoring works to commence on schedule.
CH7 For access and works within the Registered Battlefield of the Battle of Tippermuir (Site 344), the following mitigation is recommended: · All access routes and working areas where ground disturbance is expected will be marked out, in agreement with PKHT, to define the areas due to be impacted upon; · All areas marked out will be subject to archaeological works including a metal detector survey and watching brief, set out within a WSI, and in agreement with PKHT; and · Access to Tower 140 along Old Gallows Road should avoid the road where it is unaffected by modern upgrades or utilise matting to preserve one of the key elements of the battlefield.
8-21 The mitigation requirements CH3-CH7 will be undertaken in line with the following guidance set out by CIfA: · Standards and guidance for an archaeological watching brief84; · Standards and guidance for archaeological field evaluation85; · Standards and guidance for archaeological excavation86; and · Standards and guidance for the creation, compilation, transfer and deposition of archaeological archives87.
Residual Effect Following mitigation, the residual significance of effect has been reduced from Moderate to Slight on the Scheduled Monument of Dalbog House (Site 124), and the Registered Battlefield of the Battle of Tippermuir (Site 344). Mitigation strategies for both of these assets will involve proactive consultation with HES and PKHT respectively, to create strategies that allow for minimal ground disturbance and therefore provides potential reductions in the impacts from the Proposed Development.
A summary of the mitigation and residual impacts during the construction phase is set out below in Table 8-7. Only assets where the magnitude of impact was deemed to be Negligible or higher are included in the table. Apart from designated Scheduled Monuments, the other 121 assets with a magnitude of impact of No Change will not require any mitigation. Highlighted rows denote significant effects pre mitigation. For currently unknown heritage assets that may be encountered where ground breaking works are required, the residual significance of effect would be reduced from Moderate to Slight / Negligible after the heritage asset is preserved by record and a positive contribution is made to the local HER.
Table 8-7: Residual Effect Table During Construction Asset number and Pre-mitigation Effect Suggested Mitigation Measure Post-mitigation description Magnitude Significanc Magnitude Significance e 4 – Rig and Furrow Negligible Neutral Demarcation of asset and avoidance No Change Neutral 29 – Standing Stones Minor Neutral Demarcation of asset and avoidance No Change Neutral 30 – Building Minor Neutral Demarcation of asset and avoidance No Change Neutral 49 – Croft Minor Neutral Demarcation of asset and avoidance No Change Neutral 50 – Croft Negligible Neutral Demarcation of asset and avoidance No Change Neutral 68 – Farmstead Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 73 – Banks Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 79 – Field System Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 80 – Boundary Stone Negligible Neutral Demarcation of asset and avoidance No Change Neutral 83 – Earthwork Negligible Neutral Demarcation of asset and avoidance No Change Neutral 85 – Hollow Way Minor Slight Watching brief on any ground Minor Slight breaking works 86 – Earthwork Negligible Neutral Demarcation of asset and avoidance No Change Neutral 88 – Earthwork Negligible Neutral Demarcation of asset and avoidance No Change Neutral 90 – Croft Negligible Neutral Demarcation of asset and avoidance No Change Neutral
84 Chartered Institute for Archaeologists (2020) Standards and guidance for an archaeological watching brief 85 Chartered Institute for Archaeologists (2020) Standards and guidance for an archaeological field evaluation 86 Chartered Institute for Archaeologists (2014) Standards and guidance for archaeological excavation 87 Chartered Institute for Archaeologists (2014) Standards and guidance for the creation, compilation, transfer and deposition of archaeological archives 8-22 Asset number and Pre-mitigation Effect Suggested Mitigation Measure Post-mitigation description Magnitude Significanc Magnitude Significance e 124 – Cairns, Moderate Large Consultation with HES and Minor Slight Mounds, & House application for Scheduled (SM) Monument Consent 125 – Farmstead Minor Slight Watching brief on any ground Minor Slight breaking works 128 – Croft Moderate Slight Demarcation of asset and avoidance No Change Neutral 131 – Rig and Furrow Minor Slight Watching brief on any ground Minor Slight breaking works 132 – Rig and Furrow Minor Slight Watching brief on any ground Minor Slight breaking works 134 – Farmstead Minor Slight Watching brief on any ground Minor Slight breaking works 143 – Rig and Furrow Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 151 – Farmstead Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 153 – Farmstead Minor Slight Watching brief on any ground Minor Slight breaking works 156 – Farmsteads Negligible Neutral Watching brief on any ground Negligible Slight with rig and furrow breaking works 164 – Standing Stone Minor Slight Demarcation of asset and avoidance No Change Neutral (SM) 173 – Fort and No Change Neutral Demarcation of asset and avoidance No Change Neutral Settlement (SM) 175 - Cropmarks Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 181 – Enclosed No Change Neutral Demarcation of asset and avoidance No Change Neutral Settlement (SM) 183 – Ring Ditches Minor Slight Watching brief on any ground Negligible Slight breaking works 184 – Ring Ditches Minor Slight Watching brief on any ground Negligible Slight breaking works 188 – Croft Negligible Neutral Demarcation of asset and avoidance No Change Neutral 191 – Rig and Furrow Negligible Neutral Demarcation of asset and avoidance No Change Neutral 192 – Rig and Furrow Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 194 – Rig and Furrow Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 209 – Enclosure Minor Slight Demarcation of asset and avoidance No Change Neutral 214 – Souterrain and Negligible Neutral Demarcation of asset and avoidance No Change Neutral Cottage 217 – Pits Minor Slight Watching brief on any ground Negligible Slight breaking works 225 – Rig and Furrow Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 228 – Enclosure (SM) Moderate Large Demarcation of scheduled area and Minor Slight consultation with HES regarding potential for Scheduled Monument Consent
232 – Moated Minor Slight Demarcation of asset and avoidance No Change Neutral Settlement (SM) 237 – Ring Ditch (SM) No Change Neutral Demarcation of asset and avoidance No Change Neutral
8-23 Asset number and Pre-mitigation Effect Suggested Mitigation Measure Post-mitigation description Magnitude Significanc Magnitude Significance e 243 – Ring Ditches Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 248 – Ring Ditch Moderate Large Demarcation of asset and avoidance No Change Neutral (SM) 249 – Pits and Minor Slight Watching brief on any ground Negligible Slight Enclosure breaking works 251 – Settlement Minor Moderate Demarcation of asset and avoidance No Change Neutral (SM) 255 – Enclosure (SM) Minor Slight Demarcation of asset and avoidance No Change Neutral 262 – Stone Circle Moderate Large Demarcation of asset and avoidance No Change Neutral (SM) 263 – Road Negligible Neutral Demarcation of asset and avoidance No Change Neutral 264 – Road Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 266 – Pictish Stone Minor Slight Watching brief on any ground Negligible Slight breaking works 267 – Spring and Minor Neutral Watching brief on any ground Negligible Neutral Human Remains breaking works 271 – Cup and Ring No Change Neutral Demarcation of asset and avoidance No Change Neutral Marked Stone (SM) 274 – Road Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 278 – Standing Moderate Large Demarcation of asset and avoidance No Change Neutral Stones (SM) 296 – Enclosure Minor Slight Watching brief on any ground Negligible Slight breaking works 298 – Pits Minor Slight Watching brief on any ground Negligible Slight breaking works 304 – Roman Road Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 308 – Rig and Negligible Neutral Watching brief on any ground Negligible Neutral Furrow breaking works 309 – Field Boundary Negligible Neutral Demarcation of asset and avoidance No Change Neutral 312 – Field Boundary Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 323 – Water Meadow Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 328 – Railway Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 331 – Field Negligible Neutral Watching brief on any ground Negligible Neutral Boundaries breaking works 341 – Road Minor Slight Watching brief on any ground Minor Slight breaking works 344 – Battlefield Minor Moderate Consultation with PKHT regarding Minor Slight potential archaeological works 364 – Rig and Negligible Neutral Watching brief on any ground Negligible Neutral Furrow breaking works 370 – Hollow Way Negligible Neutral Demarcation of asset and avoidance No Change Neutral 377 – Rig and Furrow Negligible Neutral Watching brief on any ground Negligible Neutral breaking works 379 – Settlement Minor Slight Demarcation of asset and avoidance No Change Neutral 396 – Railway Negligible Neutral Watching brief on any ground Negligible Neutral breaking works
8-24 Asset number and Pre-mitigation Effect Suggested Mitigation Measure Post-mitigation description Magnitude Significanc Magnitude Significance e 398 – Tile Works Negligible Neutral Watching brief on any ground Negligible Neutral breaking works
Operational Phase Design Solutions and Assumptions The Proposed Development reuses the existing electrical infrastructure alongside temporary, low impact infrastructure to enable the minimal extension of 73 towers along the OHL Route. It has been assumed that the extension to the towers will match their current profile and shape to minimise any visual changes to the towers. It is also assumed that all new access tracks will be temporary and removed at the end of the construction phase. Description of Effects
Operational impacts would relate to indirect setting impacts due to the visual intrusion of new electrical infrastructure, required as part of the Proposed Development. New electrical infrastructure is required at 73 tower locations along the OHL Route in order to extend the height of the towers as detailed in Chapter 3, Table 3-1; the height extensions range from 1.5 m to 4 m. The introduction of new steelwork in the mid-section of the tower will allow the overall shape of the tower to remain relatively unaltered.
Therefore, it is not anticipated that there will be any significant operational impacts from the Proposed Development on the setting of any cultural heritage assets, and no detailed assessment on the setting of assets has been conducted.
The proposed vertical Limit of Deviation for the tower extensions would not alter the predicted effects given the relatively small difference in height extension to the detail given in Table 3-1 that this would involve.
Mitigation During Operation There is no requirement for any mitigation in relation to cultural heritage during operation of the Proposed Development.
Residual Effect The residual effects from the operation of the Proposed Development have been assessed as Neutral.
Cumulative Effects The assets affected by the construction of the Proposed Development do not have any common receptors with assets that have the potential to be impacted upon by the construction of the other cumulative schemes. Therefore, the residual construction cumulative effects are the same as those set out in Table 8-7. The identification of likely cumulative effects during operation would focus on the residual operational impacts on the setting of cultural heritage assets in combination with developments in proximity to the Proposed Development. As there are no residual operational effects related to the Proposed Development, the cumulative effects are assessed as Neutral.
8.6 Summary The majority of cultural heritage assets within close proximity to the Proposed Development will not be impacted upon by the construction works. Furthermore, mitigation in the form of site demarcation to ensure avoidance will reduce the number of significant residual effects. It has been assessed that there will be residual effects from access and construction at Tower 372 on the Scheduled Monument
8-25 of Dalbog house, fields and cairns (SM4633) (Site 124), and from access and construction at Towers 137-142 on the Registered Battlefield of The Battle of Tippermuir (BTL39) (Site 344). Subsequent to mitigation, these residual effects are not deemed to be significant. Mitigation to reduce the significance of effect on these assets will require proactive consultation with HES and PKHT respectively to agree construction methods that will allow for minimal ground disturbance within the boundaries of these assets.
8-26 9 NOISE AND VIBRATION
9.1 Introduction This chapter assesses the potential impacts on noise and vibration resulting from the Proposed Development. This chapter (and its associated Figures and Appendices) is not intended to be read as a standalone assessment and reference should be made to the introductory chapters of this Environmental Impact Assessment (EIA) (Chapters 1-5). This chapter is accompanied by the following Appendices: · Appendix 9.1 – Derived OHL Noise Data · Appendix 9.2 – Indoor Noise Reference · Appendix 9.3 – Baseline Noise Measurements · Appendix 9.4 – External BS 4142 2014 and TR(T) 94 Assessment – Full Totara Line · Appendix 9.5 – Internal Noise Assessment – Full Totara OHL · Appendix 9.6 – OHL Hybrid Design and Residual Effect
This chapter is accompanied by the following Figures: · Figure 9.1 – Wet Noise Results – Main OHL · Figure 9.2 – Wet Noise Results – Bertha Park · Figure 9.3 – Wet Noise Results – Almond Valley · Figure 9.4 – Alyth Line Diversion · Figure 9.5 – Kintore Line Diversion An energised electrical transmission OHL can be the source of an audible phenomenon known as ‘corona discharge’. This is a limited electrical breakdown of the air in the vicinity of the OHL conductors. While OHL conductors are designed and constructed to minimise corona discharge, surface irregularities such as damage, attached raindrops, insects and other types of contamination can increase local electric field strength beyond the inception level for local corona discharge at these sites. Such corona discharge can be the source of audible noise, a crackling sound accompanied sometimes by a low frequency hum. The highest noise levels generated by an OHL usually occur during light rain when water droplets, collecting on the surface of the conductor, can initiate corona discharge. The number of droplets that collect, and hence the amount of noise, depends on the rate of rainfall. Mist or fog can also cause corona discharge from droplets condensing on and attaching to the conductor surface. Sometimes, after a prolonged spell of dry weather, conductors can become contaminated with accumulated dust particles and other materials on which corona discharge can occur and audible noise can be generated. Later rain showers have the effect of washing the conductors clean of such debris.
The higher the voltage of the OHL, the higher the potential of audible noise emissions. As the OHL voltage is increasing from 275 kV to 400 kV, an increase in noise exposure for nearby noise sensitive receptors (NSRs) is likely from the Proposed Development.
There are no known vibrational impacts as the result of the operation of the Proposed Development.
9-1 9.2 Assessment Methodology and Assessment Criteria
Scope of the Assessment The National Grid has derived a procedure to assess the impact of OHL noise in both dry and wet (rain- induced) conditions in Technical Report No. TR(T) 9488. The guidance of the British Standard (BS) 4142: 201489 can also be used to assess the impact of the noise from a specific industrial source at NSRs. The procedure requires that the background noise (BGN) at NSRs within a set distance from the OHL (usually 200 m) be measured during quiet night times and in dry conditions with little wind. Also required is the nature of the ground surface type around the sensitive receptors so that the contribution to BGN of the surface noise attributable to the rainfall can be derived from empirically derived curves (Miller curves). The logarithmic sum of the measured BGN and the empirically derived contribution for rainfall is adopted as the BGN level, in wet conditions, against which to compare the predicted received noise from the OHL. Using the parameters provided in TR(T) 94 the likelihood of an adverse impact can be assessed.
The assessment procedure follows TR(T) 94, and has been conducted in the following stages: · the attended collection of night-time BGN levels at NSRs, or groups of such NSRs, within 200 m of the centreline of the OHL during suitable dry weather conditions, before construction; · allowance for the effects of rainfall on BGN; · prediction of contribution from conductors; and · determination of total excess at a statistically derived likelihood of rain rate.
A number of other planning policy and guidance documents and British Standards have informed the study. These are discussed below. British Standard 4142: 2014: Methods for rating and assessing industrial and commercial sound (BS 4142: 2014) BS 4142: 201490, describes methods for rating and assessing the following: · sound from industrial and manufacturing processes; · sound from fixed installations which comprise mechanical and electrical plant and equipment; · sound from the loading and unloading of goods and materials at industrial and / or commercial premises; and · sound from mobile plant and vehicles that is an intrinsic part of the overall sound emanating from premises or processes, such as that from forklift trucks, or that from train movements on or around an industrial and/or commercial site.
The methods use outdoor sound levels to assess the likely effects of sound on people who might be inside or outside a dwelling or premises used for residential purposes upon which sound is incident.
In accordance with the assessment methodology, the specific sound level (LAeq,T) of the noise source being assessed is corrected by the application of corrections for acoustic features, such as tonal
qualities and / or distinct impulses, to give a "rating level" (LAr,Tr). The standard effectively compares and
rates the difference between the rating level and the typical background sound level (LA90,T) in the absence of the noise source being assessed.
88 Technical Report No. TR(T) 94, 1993. A Method for Assessing the Community Response to Overhead Line Noise, National Grid Technology & Science Laboratories.
89 BS 4142: 2014, Methods for Rating and Assessing Industrial and Commercial Sound, BSI.
90 BS 4142: 2014, Methods for Rating and Assessing Industrial and Commercial Sound, BSI.
9-2 The standard advises that the time interval ('T') of the background sound measurement should be sufficient to obtain a representative or typical value of the background sound level at the time(s) when the noise source in question is likely to operate or is proposed to operate in the future. Comparing the rating level with the background sound level, BS 4142: 2014 states: · "Typically, the greater this difference, the greater the magnitude of impact. · A difference of around +10 dB or more is likely to be an indication of a significant adverse impact, depending on the context. · A difference of around +5 dB is likely to be an indication of an adverse impact, depending on the context. · The lower the rating level is relative to the measured background sound level, the less likely it is that the specific sound source will have an adverse impact or a significant adverse impact. Where the rating level does not exceed the background sound level, this is an indication of the specific sound source having a low impact, depending on the context."
Planning Advice Note (PAN) 1/2011: ‘Planning and Noise’91 Published by the Scottish Government in March 2011, this document provides advice on the role of the planning system in helping to prevent and limit adverse impacts of noise. Information and advice on noise assessment methods are provided in the accompanying Technical Advice Note (TAN): Assessment of Noise92. Included within the PAN document and the accompanying TAN are details of the legislation, technical standards, and codes of practice for specific noise issues.
Neither PAN 1/2011 nor the associated TAN provides specific guidance on the assessment of noise from fixed plant, but the TAN includes an example assessment scenario for ‘New noisy development (incl. commercial and recreation) affecting a noise sensitive building’, which is based on BS 4142: 1997: Method for rating industrial noise affecting mixed residential and industrial areas. This British Standard has been replaced by BS 4142: 2014: Methods for rating and assessing industrial and commercial sound. It is preferable that satisfactory noise levels can be achieved within dwellings with the windows sufficiently open for ventilation. Local circumstances, particularly relating to the existing noise character of the area, should influence the approach taken to noise levels with open or closed windows. It may be appropriate to take a different approach to noise levels in different areas. It may also be appropriate to take a different approach to noise levels when considering the effects of new noisy development on existing residential properties from the approach taken to new residential development close to existing noisy land uses. Satisfactory internal noise levels with open windows may not always be achievable, but are always preferable. Where satisfactory levels with open windows are not achievable, practicable mitigation solutions should be explored, considering their possible impact on the built environment. Design solutions may be possible, such as locating living rooms and bedrooms on the opposite side of a building to the source of the noise or use of windows designed to provide for ventilation while providing improved sound reduction. In some circumstances however, closed windows with alternative means of ventilation may be unavoidable.
British Standard 8233:2014: Guidance on sound insulation and noise reduction for buildings The guidance provided within the document is applicable to the design of new buildings, or refurbished buildings undergoing a change of use, but does not provide guidance on assessing the effects of changes in the external noise levels to occupants of an existing building.
91 https://www.gov.scot/binaries/content/documents/govscot/publications/advice-and-guidance/2011/03/planning-advice-note-1-2011-planning- noise/documents/0114180-pdf/0114180-pdf/govscot%3Adocument/0114180.pdf?forceDownload=true, Planning Advice Note 1/2011, Planning and Noise, The Scottish Government, last visited 18 September 2020 92 https://www.gov.scot/publications/technical-advice-note-assessment-noise/, Assessment of noise: technical advice note, The Scottish Government, last visited 18 September 2020 9-3 The guidance provided includes appropriate internal and external noise level criteria which are applicable to dwellings exposed to steady external noise sources. It is stated in the British Standard that it is desirable for internal ambient noise level not to exceed the criteria set out in Table 9-1.
Table 9-1 – Summary of internal ambient noise level criteria for dwellings from with BS 8233: 2014
Activity Location Ambient Noise Level
07:00 to 23:00 Hours, 23:00 to 07:00 Hours, i.e. Daytime i.e. Night-time
Resting Living Room 35 dB LAeq,16 hour -
Dining Dining Room/Area 40 dB LAeq,16 hour -
Sleeping (daytime Bedroom 35 dB LAeq,16 hour 30 dB LAeq,8 hour resting)
With respect to external amenity space such as gardens and patios, the standard states that it is desirable that the noise level not exceed 50 dB LAeq,T, with an upper guideline value of 55 dB LAeq,T which would be acceptable in noisier environments. Higher external noise criteria may be appropriate under certain circumstances such as within city centres, other urban areas and locations adjoining the strategic transportation network, where it may be necessary to compromise between elevated noise levels and other factors such as convenience of living, and efficient use of land resource.
Extent of the Study Area The extent of the Proposed Development is detailed in Chapter 3. The Proposed Development is made up of three areas of consideration – the existing properties along the OHL route (here after referred to as the “Main OHL” assessment), the Bertha Park residential development and the Almond Valley residential development. As Bertha Park and Almond Valley are in the process of development, their assessment summaries are sometimes grouped together as “Future Developments”. Buffer zones of 50 m and 200 m were created on either side of the Proposed Development centreline. Properties that fell within the 200 m buffer were to be assessed as NSRs. These NSRs were mapped using OS address base data and satellite imagery of the area. It should be noted that for the Future Developments some properties beyond the 200 m buffer have been assessed. While a 200 m buffer was appropriate for the majority of the line, these areas were particularly dense with residential properties. In these high density areas, some properties outside of the 200 m buffer have been included to ensure no impacts were omitted.
Consultation The Proposed Development passes through three separate council regions – Perth and Kinross, Angus, and Aberdeenshire. The relevant Environmental Health Officer (EHO) in each of these regions was consulted. Consultation responses are summarised in Table 9-2.
9-4 Table 9-2 – Consultation responses of relevance to noise
Organisation Type of Consultation Response How response has been considered Angus Council (EHO) Discussion of Agreement that BS 4142: Detailed methodology assessment methodology 2014 and TR(T) 94 and assessment and appropriate limits. criteria are used for the significance matrix were An NR rating level of assessment of external sent to each respective NR20 was originally the noise. EHO for review. set limit under all BS 5228 is also an Conservative conditions, concerns appropriate method of assessment criteria and raised wghere this may assessment for internal conditions were aligned not be appropriate under noise. for each council area. wet conditions due to elevated BGN. Perth and Kinross Discussion of Agreement that BS 4142: Detailed methodology Council (EHO) assessment methodology 2014 and TR(T) 94 and assessment and appropriate limits. criteria are used for the significance matrix were An NR rating level of assessment of external sent to each respective NR20 was originally the noise. EHO for review. set limit under all BS 5228 is also an Conservative conditions, concerns appropriate method of assessment criteria and raised wghere this may assessment for internal conditions were aligned not be appropriate under noise. for each council area. wet conditions due to elevated BGN. Aberdeenshire Council Discussion of Agreement that BS 4142: Detailed methodology (EHO) assessment methodology 2014, TR(T) 94 and and assessment and appropriate limits. BS 5228 are appropriate significance matrix were methods of assessment sent to each respective for the external amenity. EHO for review. Conservative assessment criteria and conditions were aligned for each council area.
Method of Baseline Data Collation NSRs were classified as properties situated within 200 m of the centreline of the Proposed Development. Appropriate noise measurement locations were selected that were representative of the receptors that fell within this range. Once the NSRs had been identified and characterised, site visits were made at appropriate times and in suitable weather windows and attended BGN levels measured, over the course of six surveys. A total of 265 existing NSRs were identified. In addition, two new housing developments, Bertha Park and Almond Valley, were identified within 200 m of the Proposed Development. Bertha Park is a consented housing development (Application reference: 15/01112/IPM and 15/01109/FLM) and is currently under construction. The Almond Valley housing development currently has planning permission in principle (Application ref: 15/01157/IPM) from Perth & Kinross Council, and a detailed planning application for the first phase of the development (application ref: 19/01430/AMM) is currently awaiting determination. When local clusters of houses are clustered together as a single receptor, Bertha Park has 271 NSRs, and Almond Valley has 654 NSRs. The population density of the developments will increase the sensitivity over that of isolated properties. See Figure 5.1: Cumulative Developments and Chapter 5, Table 5-2 for more information on these schemes. Due to the large number of receptors involved, it was only feasible to conduct attended spot measurements at the NSRs as specified in TR(T) 94, rather than long-term unattended measurements. The nature of the ground cover and assignment of Miller ratings, required for the evaluation of rainfall contributions to BGN, was assessed during the noise surveys.
9-5 Where the Proposed Development meets properties in groups or close settlements, one location has been chosen as representative of several properties that would produce duplicate readings. Surveys were conducted and measurements near the receptors were taken during quiet night-time conditions (specified within TR(T) 94 as between 23:00 and 06:00), in suitable weather conditions.
Instrumentation Measurements were conducted using three Rion NL-52 sound level meters (SLMs) of serial numbers (S/N) 00175536, S/N 01265413 and S/N 01265432, which were spot calibrated with a Rion NC-74 calibrator S/N 341748103, before and after the measurement campaign, no significant drift was recorded during these calibrations. The meters were mounted on tripods in a free field location. Instrument calibration certificates are available on request.
Measured Parameters
· LA90
· LAeq · One-third octave band spectra
The parameter defining BGN is the LA90 percentile exceedance level, which was measured at each NSR during each survey. The measurement period was 5 minutes, as described by TR(T) 94.
The LA90 percentile of all the levels within each averaging period is used. This descriptor removes the influence of short-term transient events that may artificially increase the level to give the best representation of a background level. Even so, if an audible extraneous event, such as an immediately passing road vehicle, occurred during the measurement period the acquisition of data was temporarily interrupted and resumed when that event became inaudible. Meteorological Conditions
As the survey consisted of attended spot measurements, the survey was timed when environmental conditions were compliant with BS 4142: 2014 criteria.
Assessment Modelling Using published rainfall noise data and the above measured dry BGN levels together with a description of the ground cover and the sound power data for the conductors, the emission of conductor noise has been predicted and its impact on the NSRs assessed under dry and wet conditions.
A computer model of the Proposed Development has been constructed. The input for specific conductor noise has been received from the Applicant supplied data included in Audible Noise Testing Report (2020)93, the data have been derived from studying the line conductor properties in Graz, Austria. Bonneville Power Administration (BPA) calculations for audible noise during wet conditions have also been supplied by the Applicant. The distance between the line source and NSR have been calculated using available line geometry, assuming a lower conductor height (Z) of 11 m. The calculation considers X,Y,Z coordinates of the OHL towers with respect to NSR coordinates to determine an accurate distance from source to receiver. A TR(T) 94 assessment has been conducted to determine the threshold distance where the results show that complaints are likely, rather than no observed reaction. The TR(T) 94 assessment assesses the impact of noise during dry and wet conditions, based on the sound power level per metre of the conductor and the BGN level. The predicted noise level at the receptor is calculated based on a propagation model.
93 70067987, Audible noise testing report, WSP, June 2020 9-6 Dry Assessment
The noise impact from the Proposed Development during dry conditions has been assessed using the BS 4142: 2014 noise assessment approach. The excess dry figure is calculated by assuming attenuation of 11.4 dB for each factor of 10 in distance or “11.4 dB/decade”. This is consistent with the BPA method of calculating OHL noise. This assumes the OHL produces no tonal or other distinctive noise characteristics when dry. The dry noise input level from the Twin Totara type conductor bundle configuration has been taken from the Audible Noise Testing Report. Giving the following reference value: · 25.0 dB(A) at reference distance 10 m.
This value has been used in the following formula for each receptor: ( ) = 25.0 − 11.4 10 − 10 Where; R= geometric distance to receptor, including elevation (Z) + height of the line (11 m). BGN = assigned background noise at the receptor. Wet Assessment During wet conditions, the noise output from OHLs vary according to the number and size of rain droplets accumulated on the surface of the conductors. Therefore, there is a strong relationship between the rainfall rate and the noise output from an OHL. BGN levels also increase with rainfall rate, such that during very heavy rain noise is generally inaudible. For these reasons, an alternative noise assessment method to deal with rain-induced noise is required. The external rain-induced noise levels will be assessed using the methodology developed by National Grid and detailed in their Technical Report TR(T) 94, which is recommended by the Department of Energy & Climate Change for the assessment of rain induced noise. The excess wet figure is derived by integrating the total noise as a function of rain rate, weighted according to the probability of a given rain rate. The rain distribution is taken from Met Office data for Braemar, January 1990 to March 2020, assuming a lognormal distribution. These data have been used alongside the assumption that the percentage of the year it is raining is 14%, taken from previous EIAs. · Mean Annual Rain (mm/year) = 930 · Mean Annual Rain (hours) = 1200 hours · Mean Rain Rate (mm/hour) = 0.76 · Standard deviation of the logarithm = 0.95
The excess wet figure is compared against a BGN level calculated through the addition of dry BGN levels and predicted noise due to rainfall according to the Miller curve value for that specific NSR. Miller curve descriptions are provided in Table 9-3.
9-7 Table 9-3 - Miller Curve Description
Miller Curve Description
Essentially bare, porous ground (that is ploughed field or snow covered ground); no R-1 standing puddles or water. Relatively small-leafed ground cover vegetation, such as grass lawn, meadow, hayfield shortly after mowing, field of small-leaf plants. Non-porous, hard, bare ground or pavement, falling raindrops splash on thin layers of puddles of collected water; or in or beside wooded area of deciduous trees without leaves R-2 or with only small leaves; or in or beside wooded area of coniferous trees or evergreens having needles rather than leaves; or thin-leafed ground cover of crop, such as hay, clover, or grain. A few small, fully leafed deciduous trees 15 to 30 m or a few large, fully leafed trees 30 to R-3 90 m distance. Large area of fully leafed trees or large-leafed crops or vegetation, such as corn starting 15 R-4 to 30 m distance. Large area of fully-leafed trees or large-leafed crops or vegetation entirely surrounding the R-5 area of interest.
The wet sound levels for Twin Totara type conductor bundles are based on calculated data using the BPA method at 1 mm/hr and are presented in Appendix 9.1. It is noted that from towers 34 to 88 type L2 towers are implemented, thereafter type L8.
The total noise is integrated over rain rates, weighted according to the probability of a given rain rate, a 5 dB tonal penalty has been applied at rain rates over 1 mm/hr in accordance with BS 4142: 2014 and TR(T) 94.
Internal Noise Assessment The TR(T) 94 calculations are conducted against night-time BGN for the external amenity of the property for a worst-case assessment. It is reasonable to assume that during night, and particularly during wet conditions, inhabitants will be indoors. Therefore, it is important to also consider indoor noise levels alongside this assessment. Measured one-third octave test data have been provided for wet noise input source levels.
Nominal operational voltage is indicated to be 230 kV for the conductors, therefore the spectrum used has been the untreated Twin Totara at 1 mm/h. These data are presented in Appendix 9.1. The spectrum has been calibrated for different distances up to 100 m to the calculated BPA method data to form a worst case data set. A correction value has been calculated from subtracting the noise measured noise at source and calculated noise at distance and applied to the one-third octave spectra. The data are presented in Appendix 9.1.
Indoor building properties have been assumed as realistic but conservative values for the assessment, and indoor noise has been calculated for the nearest NSRs. The assumptions made are presented in Appendix 9.2.
The sound reduction calculations are summarised in Table 9-4 and Table 9-5 for both open and closed window states. Where R is sound reduction of materials, is absorption, A(m2) is absorption x total area, L2-L1 is level difference.
9-8 Table 9-4: Sound Reduction – Open Window
Attribute Frequency (Hz)
63 125 250 500 1000 2000 4000
R composite (dB) 26.6 22.7 22.7 24.7 22.8 25.8 27.8
α 0.1 0.3 0.1 0.1 0.1 0.1 0.1
A (m2) 11.9 23.9 14.0 12.3 9.7 8.9 9.7
L2-L1 (dB) -19.6 -18.7 -16.4 -17.9 -14.9 -17.6 -19.9
Average reduction 17.8 dB
Table 9-5: Sound Reduction – Closed Window
Attribute Frequency (Hz)
63 125 250 500 1000 2000 4000
R composite (dB) 25.3 29.8 33.0 37.2 38.2 40.7 47.4
α 0.1 0.3 0.1 0.1 0.1 0.1 0.1
A (m2) 11.9 23.9 14.0 12.3 9.7 8.9 9.7
L2-L1 (dB) -18.3 -25.8 -26.7 -30.3 -30.3 -32.4 -39.5
Average reduction 24.9 dB
In order for indoor noise to be calculated using absolute levels rather than individual spectra for every receptor, an average reduction in noise provided by each window state has been calculated. The average reduction for an open window (Table 9-4) and closed windows (Table 9-5) has been subtracted from the wet noise external BGN for each receptor to calculate an approximate indoor BGN. As there is octave date for the conductors, the reduction of their specific noise can be calculated using spectra rather than absolute values. Applying the sound reduction to the input spectra of the OHL results in the following overall reduction in specific OHL noise levels: · Open Window = 17.2 dB · Closed Window = 28.2 dB These values have been subtracted from the specific external OHL levels.
Determining Magnitude of Change Sensitivity of Receptors The assessment considers the descriptors for determining sensitivity of NSRs in Table 9-6.
9-9 Table 9-6: Receptor Sensitivity
Sensitivity Application
High Private dwellings, hospitals, libraries, museums, schools, flats, hotels
Medium Restaurants, offices, shops, theatres, cinemas
Low Unoccupied properties, factories, engineering works
Negligable Vacant land
All NSRs considered in the assessment are residential dwellings, therefore the sensitivity of all NSRs is high. Magnitude of Change There are differences in assessment methods for dry and wet conditions, with dry assessments indicating the excess of rating level over background and wet conditions assessing the weighted mean increase in noise levels, dry and wet predictions are assessed differently. Dry Line Noise Impacts
Comparing the rating level with the background sound level, BS 4142: 2014 states: · "Typically, the greater this difference, the greater the magnitude of impact. · A difference of around +10 dB or more is likely to be an indication of a significant adverse impact, depending on the context. · A difference of around +5 dB is likely to be an indication of an adverse impact, depending on the context. · The lower the rating level is relative to the measured background sound level, the less likely it is that the specific sound source will have an adverse impact or a significant adverse impact. Where the rating level does not exceed the background sound level, this is an indication of the specific sound source having a low impact, depending on the context." Wet Line Noise Impacts TR(T) 94, similarly to BS 4142: 2014, recognises the following thresholds by which the new sound level exceeds the background noise, and the likely community response. The criteria are outlined in Table 9-7.
Table 9-7: Subjective Effect of Changes in Noise Level (Hassall & Zaveri, 1988)
Amount in dB(A) by which the new Category Description sound level exceeds the background noise
0 None No observed reaction
5 Little Sporadic complaints
10 Medium Widespread complaints
15 Strong Threats of community action
20 Very Strong Vigorous community action
An exceedance of 5 dB or higher would be an indication of adverse impact. An exceedance of 10 dB or higher would be an indication of significant adverse impact. Indoor Noise Impacts
Indoor noise has been considered in accordance with BS 8233: 2014. The criteria are outlined in Table 9-8.
9-10 Table 9-8 – Summary of internal ambient noise level criteria for dwellings from with BS 8233: 2014
Activity Location Ambient Noise Level
07:00 to 23:00 Hours, 23:00 to 07:00 Hours, i.e. Daytime i.e. Night-time
Resting Living Room 35 dB LAeq,16 hour -
Dining Dining Room/Area 40 dB LAeq,16 hour -
Sleeping (daytime Bedroom 35 dB LAeq,16 hour 30 dB LAeq,8 hour resting)
The night-time bedroom limit of 30 dB has been applied in this assessment During wet conditions there is a substantial increase in BGN due to rain interaction. In some cases, the increase in BGN is a major contributor to noise levels up to the 30 dB level. Excess values from BS 4142: 2014 should be also applied to the criteria to define the impact of the Proposed Development. NR curves have also been calculated and presented for reference in the assessment.
Significance Criteria The following significance criteria have been determined for the external noise assessments:
Table 9-9: External Noise Criteria
Impact Significance Criterion
Low Excess below 5 dB
Adverse Excess of 5 dB or more
Significant Adverse Excess of 10 dB or more
The external noise criteria are in line with BS 4142: 2014 and TR(T) 94. The following significance criteria have been determined for the internal noise assessments:
Table 9-10: Internal Noise Criteria
Impact Significance Criterion Excess of 0 dB or less Low OR Total noise is below 30 dB AND excess is below 5 dB Total noise is below 30 dB AND excess is 5 dB or more Adverse OR Total noise is above 30 dB AND excess is below 5 dB Total noise is above 30 dB AND excess is 5 dB or more Significant Adverse OR Excess of 10 dB or more
The internal noise criteria are in line with BS 8233: 2014 for night-time sleep and incorporate BS 4142: 2014 excess levels.
9-11 9.3 Baseline Conditions All properties situated within 200 m of the transmission line along the Proposed Development have been classified as NSRs for the purposes of this assessment. The majority of receptors are widely dispersed over a rural area, with some of constituting higher populated urban areas mainly around the city of Perth. A total of 265 existing NSRs have been identified. There are also two new-build developments in planning or ongoing construction, Bertha Park with an additional 271 receptors and Almond Valley with 654 receptors. These developments are more densely populated and contain a large number of receptors within a small area close to the Proposed Development. Appropriate noise measurement locations were selected that were representative of the receptors that
fell within this range. The BGN level is the measured external 5-minute A-weighted L90 value at night- time. Using this value as BGN for assessment purposes ensures a worst-case assessment, as an equivalent daytime level is expected to be up to 10 dB higher depending on location. The locations and the BGN levels measured are shown in Appendix 9.3.
Future Baseline For most receptors, it is assumed that there will be limited to no change in BGN levels. A large portion of the NSRs are in isolated rural areas, with no foreseeable future development plans. For the areas of the proposed Bertha Park and Almond Valley housing developments, it is expected that background noise conditions in the area are subject to change. Due to the construction of the projects, it is expected that additional infrastructure and population density in these areas are likely to lead to an increase in BGN levels in the area. The increase in background noise for the developments would only have an impact on the dry noise assessment. Changes to the wet noise assessment would be negligible due to increases in background noise dependant on the miller curve rating, which will remain the same.
9.4 Issues Scoped Out The sections below provide the rationale for excluding certain noise effects from the EIA. Construction Noise Construction noise will be short term and intermittent, with potential noisy activities, such as tower steel reinforcements and foundation upgrades, taking approximately three to four days to complete per tower location. As such, it is considered that construction noise can be controlled through the implementation of a Noise Management Plan, which would be developed as part of the CEMP prepared by the Principal Contractor. The Noise Management Plan would detail how construction noise would be mitigated in line with BS 5228: 2014 – Noise and Vibration Control on Construction and Open Sites. Therefore, no detailed assessment of construction noise associated with plant noise or traffic is proposed as part of this EIA. Noise from Operational Maintenance Any operational maintenance works required along the line will be short term and intermittent and are not anticipated to give rise to significant effects relating to noise and vibration. Therefore, no detailed assessment of operational noise associated with maintenance is proposed as part of this EIA.
9-12 9.5 Assessment of Effects, Mitigation and Residual Effects
Operational Phase Design Solutions and Assumptions The main conductor considered for the Proposed Development is the Twin Totara type conductor bundle. Input noise levels are provided in Table 9-11.
Table 9-11: Twin Totara Wet Audible Noise Levels at 1 mm/hr
Line Type Audible Noise (dB) at Distance (m)
0 10 20 30 40 50 60 70 80 90 100
L8 Twin 54.9 54.4 52.9 51.5 50.4 49.4 48.5 47.8 47.2 46.6 46.1 Totara
L2 Twin 56.1 55.6 54 52.6 51.4 50.5 49.6 48.9 48.3 47.7 47.2 Totara
An alternative conductor has been identified that can be used on specific section of the Proposed Development. The alternative triple (AL4)Upas equivalent type conductor bundle can replace twin Totara at specific locations. Audible noise for the alternative conductor has been calculated using the BPA method, and presented in Table 9-12.
Table 9-12: Triple (AL4)Upas Wet Audible Noise Levels at 1 mm/hr
Line Type Audible Noise (dB) at Distance (m)
0 10 20 30 40 50 60 70 80 90 100
L8 UPAS 45.9 45.4 43.9 42.5 41.4 40.4 39.5 38.8 38.2 37.6 37.1
L2 UPAS 47.1 47.6 45 43.6 42.4 41.5 40.6 39.9 39.3 38.7 38.2
The data shows that a (AL4)Upas equivalent conductor bundle offers a 9 dB reduction from twin Totara. The assessment has considered potential significant impacts from operational OHL noise due to “corona discharge”, during both dry and wet conditions for both conductors.
Description of Effects External Noise Noise from a twin Totara conductor bundle has been considered. A summary of results is provided in Table 9-13 below. A full set of results are provided in Appendix 9.4.
Table 9-13: Summary of Twin Totara External Results – Existing Receptors
Assessment Criteria Dry Conditions Wet Conditions
Low 265 46
Adverse 0 160
Significant Adverse 0 59
A summary of results for the future developments of Bertha park and Almond Valley is presented in Table 9-14.
9-13 Table 9-14: Summary of Twin Totara External Results – Future Developments
Assessment Criteria Dry Conditions Wet Conditions
Low 926 1
Adverse 0 720
Significant Adverse 0 205
The breakdown of results shows that for dry conditions, the entirety of the OHL has Low impact of for a twin Totara conductor bundle arrangement.
For a proportion of the year (14%) the Proposed Development will be operating under wet conditions. Wet noise conditions are when noise from the OHL is at its loudest; however, responses vary widely with specific conditions of the NSRs. Adverse impacts are likely due to these conditions for the majority of the line, and an increase in sporadic complaints. The assessment concludes that there are a high proportion of Significant Adverse impacts, which would result in widespread complaints. The modelling and assessment calculations have been repeated for the alternative triple (AL4)Upas equivalent conductor bundle. The assessments show that triple (AL4)Upas equivalent conductor bundles are an effective option for eliminating Significant Adverse impacts. There remains a number of Adverse impacts for the external assessments.
Internal Noise The calibrated reduction levels have been applied to the twin Totara wet noise assessment levels and applied to the indoor noise criteria. A summary of results is provided in Table 9-15 below. A full set of results are provided in Appendix 9.5.
Table 9-15: Summary of Twin Totara Internal Results – Existing Receptors
Wet - Window Assessment Criteria Dry - Window Open Wet - Window Open Closed
Low 265 71 186
Adverse 0 65 65
Significant Adverse 0 129 14
A summary of internal assessment results for the future developments of Bertha park and Almond Valley are presented in Table 9-16.
Table 9-16: Summary of Twin Totara Internal Results – Future Developments
Assessment Criteria Dry - Window Open Wet - Window Open Wet - Window Closed
Low 926 82 472
Adverse 0 467 380
Significant Adverse 0 377 74
The assessment concludes that for all NSRs, indoor noise during dry conditions is of Low impact. For wet conditions with an open window there is an increase in Adverse impact, and the majority of NSRs are predicted to experience Significant Adverse impact. For wet conditions with the window closed, there is significant reduction in the level of Significant Adverse impact. The majority of NSRs are predicted Low impact and there remains a proportion of Adverse impact.
9-14 Calculations have been repeated for triple (AL4)Upas equivalent conductor bundles. The assessments show that triple (AL4)Upas equivalent conductor bundles are an effective mitigation option for eliminating Significant Adverse impacts. There remains a number of Adverse impacts for the internal assessments.
OHL Route Design The intension is to replace the existing twin conductors with new twin conductors. Where there are environmental constraints, the final design of the OHL Route will include alternative twin or triple conductor equivalents.
Operational Mitigation No further mitigation has been proposed at this stage of the project. Any Significant Adverse impacts have been identified and designed out. This has been achieved by considering which conductor may be best suited to each span and on this basis planning a hybrid conductor arrangement. The details of this conductor arrangement are presented in Appendix 9.6. N1 – Site specific surveys can be undertaken at NSRs with remaining Adverse impacts. These surveys can be used to inform any requirements for secondary mitigation measures. These further measures could be considered to address issues on a case by case basis, subject to further study and detailed design in advance of construction.
Residual Effects A review of the Proposed Development and impacts have been conducted to identify where the use of the triple (AL4)Upas equivalent conductor bundle is required. The design plan and full results of the residual effects assessment is presented in Appendix 9.6.
The design of the OHL results in the residual effects shown in Table 9-17 and Table 9-18.
Table 9-17: Residual Impacts – Current Receptors
Hybrid Conductor Arrangement Assessment Criterion External Noise Internal Noise
Low 214 230
Adverse 51 35
Significant Adverse 0 0
Table 9-18: Residual Impacts – Future Receptors
Hybrid Conductor Arrangement Assessment Criterion External Noise Internal Noise
Low 908 903
Adverse 18 23
Significant Adverse 0 0
The hybrid utilisation of a twin Totara conductor bundle and a triple (AL4)Upas equivalent conductor bundle will result in no Significant Adverse effects for receptors. A proportion of Adverse effects will remain.
9-15 Limitations and Assumptions As is the nature of OHL noise, the magnitude of noise generation and excess is based on varying environmental factors. There will be periods under certain conditions where excess noise from the OHL is more prominent, and times when it is less prominent. The excess wet figure is derived by integrating the total noise as a function of rain rate, weighted according to the probability of a given rain rate. The TR(T) 94 assessment methodology seeks to apply an overall excess value according to these statistics. This is demonstrated as an example in Chart 9-1 where it is clear that excess levels are higher at lower rain rates. The mean rain rate for the site is 0.76 (mm/hour), therefore audible noise levels have more weighting around this figure to produce an overall level.
Chart 9-1 - Wet Induced Background and Specific Audible Noise with Rain Rate
65
60
55
50
45
40 Level (dB) Level 35
30
25 0.01 0.1 1 10 100 Rainfall (mm/hr)
Total Miller + rain OHL
Cumulative Effects The cumulative impacts of a number of developments have been scoped in Table 9-19.
Table 9-19: Other developments considered in the cumulative assessment
Application reference Location Status Comment name
North East 400 kV Commences north from Consented No receptors from this assessment fall Overhead Line northern most point of the within 200 m of the North East 400 kV Reinforcement Works Proposed Development line. Alyth OHL diversion OHL connecting to Alyth Consented Considered substation Kintore OHL diversions OHL connecting into Awaiting Considered Kintore substation Decision Craigneil Wind Farm Craigneil Windfarm Land Awaiting Wind farm noise tends to be only To The North And North Decision significant at moderate wind speeds (6 East Of Hillside Rickarton to 9 m/s at 10 m) and in dry weather. Stonehaven At lower wind speeds, wind turbines are very quiet (or not turning) and at higher wind speeds, the background noise continues to rise, while the turbine levels off.
9-16 Application reference Location Status Comment name In dry conditions the OHL impact is low, therefore the cumulative effect will be low. In wet conditions, when the OHL is at it’s loudest, background noise due to rain will generally dominate wind farm noise and cumulative effect will be low. Kintore Substation 400 kV Land to the West of Kintore Consented Considered Extension Electricity Substation Leylodge Kintore Aberdeenshire AB51 0X Alyth Substation Land 450 Metres North Approved Considered West of Haughend Farm Meigle Marlee Quarry Extension Marlee Quarry Essendy Awaiting Quarry noise is expected only to impact decision daytime noise during working hours. In dry conditions the OHL is compliant. In wet conditions the increase in background and OHL noise is likely to mask noise from the quarry. Therefore the cumulative impact is predicted as low. Norwood Farm Poultry Norwood Farm Meikleour Approved Noise from the OHL is at its highest Rearing Shed Perth PH2 6EN during wet conditions. Wet conditions also increase the background noise. It is likely that during times when the OHL has most impact at NSRs, conditions will mask any noise from the development. Therefore cumulative impact is predicted as low. Cross Tay Link Road A9 Over the River Tay to Awaiting Road noise would be assessed for its the A93 And A94 North of decision own application. Road noise would Scone Cross Tay Link Road form an increase in dry background noise when compared to the noise from the OHL. In wet weather, rain noise would largely mask road noise. An increase in road noise would help mask the OHL noise. Therefore, cumulative effects are predicted as low. Luncarty South Residential Land 250 Metres South- Approved Residential developments would be and Employment East Of Wilmarean subject to short term construction noise Development Luncarty impacts which should be assessed in the developments own planning submission. There are no expected operation noise impacts, therefore no long term cumulative effects are predicted. Bertha Park Residential Land At Bertha Park Perth Approved Resdiential developments would be Development subject to short term construction noise impacts which should be assessed in the developments own planning submission.
9-17 Application reference Location Status Comment name There are no expected operation noise impacts, therefore no long term cumulative effects are predicted. Bertha Park Residential Land At Bertha Park Perth Approved Resdiential developments would be Development subject to short term construction noise impacts which should be assessed in the developments own planning submission. There are no expected operation noise impacts, therefore no long term cumulative effects are predicted.
Scone North Residential Scone North Scone Approved Resdiential developments would be Development subject to short term construction noise impacts which should be assessed in the developments own planning submission. Almond Valley Residential Land Adjacent to Awaiting There are no expected operation noise Development Huntingtowerfield And decision impacts, therefore no long term Ruthvenfield cumulative effects are predicted. Huntingtowerfield Almond Valley in Principle Land Adjacent to Approved on Resdiential developments would be Huntingtowerfield And appeal subject to short term construction noise Ruthvenfield impacts which should be assessed in Huntingtowerfield the developments own planning submission. Former Murray Royal Former Murray Royal Awaiting There are no expected operation noise Hospital Residential Hospital Muirhall Road decision impacts, therefore no long term Development Perth cumulative effects are predicted. Perth West Residential Perth West (mu70) Old Awaiting Resdiential developments would be Development Gallows Road Perth decision subject to short term construction noise impacts which should be assessed in the developments own planning submission. Aviva Wind Turbine Aviva Headquarters Refused Wind farm noise tends to be only Pitheavlis Perth, PH2 0NH significant at moderate wind speeds (6 to 9 m/s at 10 m) and in dry weather. At lower wind speeds, wind turbines are very quiet (or not turning) and at higher wind speeds, the background noise continues to rise, while the turbine levels off. In dry conditions the OHL impact is low, therefore the cumulative effect will be low. In wet conditions, when the OHL is at it’s loudest, background noise due to rain will generally dominate wind farm noise and cumulative effect will be low. SPEN East Coast Upgrade From T33 south n/a No receptors from this assessment fall from T33 south within 200 m of the SPEN East Coast Upgrade line.
9-18 Line Diversions
The effect of additional and temporary line diversions was also considered around Alyth and Kintore Substation. Alyth OHL Diversion
The OHL diversions at Alyth affect two receptors considered in the baseline assessment (92 and 93), as well as two receptors outside of the baseline assessment’s scope (1A and 2A). The locations and Miller curves of these receptors are shown in Table 9-20. A map of the area is presented in Figure 9.4.
Table 9-20: Alyth OHL Line Diversion Receptors
Assigned BG Noise NSR ID X Y Location Miller Curve
92 329118 747136 46 R-2
93 329195 746902 46 R-2
1A 329417 746374 46 R-2
2A 329433 746356 46 R-2
The noise impact of the OHL diversions has been considered. The NSRs benefit from the Main OHL being designed with alternative conductors, therefore it is assumed the diversions will also be constructed with the alternative conductor. It should be noted that as receptors 1A and 2A are approximately 750 – 790 m away from the Main OHL, its impact on them has not been assessed - as this will be insignificant. However, these receptors have been assessed against the temporary and proposed line diversions cumulatively – as these will be much closer to the properties. The OHL diversion results are shown in Table 9-21.
Table 9-12: Proposed Alyth OHL Line Diversion
Cumulative Noise Excess Proposed OHL Diversion Noise (Main OHL + OHL (Main OHL + OHL NSR ID Distance to OHL (m) (dB) Diversion) (dB) Diversion) (dB)
92 314 32.14 42.92 5
93 190 34.55 40.88 3
1A 421 30.72 30.72 -7
2A 445 30.45 30.45 -8
The noise impact of the temporary line was considered. It should be noted that these are the results of a worst case assessment made using a triple (AL4)Upas equivalent conductor bundle, which will have higher noise levels than the planned conductor. The temporary lines will be strung with Zebra, which will be significantly lower than modelled - and therefore insignificant. The temporary line results are shown in Table 9-22.
Table 9-22: Temporary Alyth OHL Diversion
Cumulative Noise Excess Temporary Temporary OHL Noise (Main OHL + (Main OHL + NSR ID Distance to Line (m) (dB) Temporary OHL (dB) Temporary Line) (dB)
92 360 34.52 43.18 5
93 160 37.17 41.65 3
1A 102 37.53 37.53 -1
2A 117 36.84 36.84 -1
9-19 The permanent and temporary OHL diversion impacts have been considered together in Table 9-23. It is assumed that the temporary OHL will be removed when the permanent OHL is energised and therefore not cumulative.
Table 9-23: Alyth OHL Diversion Cumulative Effects
Excess Proposed Max Main Line (Main OHL + Excess Temporary Increase Overall Proposed OHL) (Main OHL + Temporary NSR ID Noise Excess main OHL (dB) (dB) Line) (dB)
92 42.54 3 5 5 2
93 39.73 -3 3 3 6
1A N/A N/A -7 -1 N/A
2A N/A N/A -8 -1 N/A
The cumulative effect of Alyth OHL diversions will increase noise exposure at NSR 92 by 2 dB and 93 by 6 dB. This increase will adjust the impact for NSR 92 from Low to Adverse.
Kintore OHL Diversion Two line diversions at Kintore are planned, Phase 1 in 2023 and Phase 2 in 2026. Phase 1 consists of Rothinorman-Kintore (north diversion) and Phase 2 consists of Blackhillock-Kintore (west most diversion). The OHL diversions affect two receptors considered in the baseline OHL assessment (1 and 2), an additional receptor (1B) next to NSR1 and another additional property to the north of the substation (2B). The locations and Miller curves of these receptors are shown in Table 9-24. A map of the area is presented in Figure 9.5.
Table 9-24: Kintore OHL Diversion Receptors
Assigned BG Noise NSR ID X Y Location Miller Curve
1 376510 814112 2 R-3
2 377059 814091 1 R-4
1B 376454 814086 2 R-3
2B 376866 815260 1 R-3
The noise impact of the proposed line diversion in Phase 1 from Rothinorman-Kintore only effects 2B, as the receptors as it is a sufficient distance away (far more than 200 m as considered in the main assessment). This receptor is not considered further in the cumulative assessment, as it is approximately 1 km from the Main OHL. This receptor has been assessed in Table 9-25.
Table 9-25: Proposed Diversion Phase 1 Kintore OHL
NSR Distance to Line (m) Background Noise Diversion Phase 1 OHL Excess ID Noise (dB)
2B 199.71 43.92 43.32 0
For Phase 2 there are some temporary OHL diversions which will be removed before energisation of the main Proposed Development and diversions. These have been assessed cumulatively in Table 9-26.
9-20 Table 9-26: Temporary Kintore OHL Diversion Phase 2
Cumulative Noise Cumulative Excess NSR Temporary OHL 1 Temporary OHL 2 (Temporary OHL 1 and (Temporary OHL 1 + 2) ID Noise (dB) Noise (dB) 2 and BGN) (dB) (dB)
1 42.23 39.14 45.71173 5
2 37.58 38.93 44.17575 0
1B 40.52 38.52 44.86958 4
The noise impact of the proposed line diversion for Phase 2 was considered. These results are shown in Table 9-27.
Table 9-27: Proposed Diversion Phase 2 Kintore OHL
Cumulative Noise Cumulative Excess NSR Diversion Phase 2 OHL (Main OHL + Diversion (Main OHL + Diversion ID Distance to Line (m) Noise (dB) Phase 2) (dB) Phase 2) (dB)
1 110.66 46.18 48.82 8
2 453.20 39.47 47.93 4
1B 143.15 44.93 48.18 7
The permanent and temporary OHL diversion impacts have been considered together in Table 9-28. It is assumed that the temporary OHL will be removed when the permanent OHL is energised and therefore not cumulative.
Table 9-28: Kintore OHL Diversion Cumulative Effects
Main Line Cumulative Excess Cumulative Excess Max Overall (Temporary OHL 1 (Main OHL + Diversion Increase NSR ID Noise Excess main OHL (dB) + 2) (dB) Phase 2) (dB)
1 45.40 4.00 5 8 4
2 47.26 3.00 0 4 1
1B - 4 (assumed) 4 7 3
The cumulative effect of Kintore OHL diversions will increase noise exposure at NSR 1 by a maximum 4 dB and NSR 2 by 3 dB. This increase will adjust the impact for NSR 1 from Low to Adverse and similarly for NSR 1B. Substations
In addition to OHL noise, substations contain various potential sources of environmental noise, the most significant of which are transformers and associated cooling equipment. The noise from these sources is usually steady and is assessed using standard noise assessment techniques.
Substation sites will have their own noise impact assessments conducted for their planning conditions. Alyth Substation Alyth substation is not yet constructed and still at the planning stage, therefore levels are based on current site designs and calculations. A pre-planning noise impact assessment has been conducted for Alyth substation detailed in Wood report VDN.803879.R.00394. The report specifies mitigation for the site to meet assessment criteria, therefore the mitigated levels are assumed for this cumulative assessment.
94 VDB.803879.R.003, Alyth Substation – Noise Mitigation Assessment, Wood, February 2020 9-21 The site is located approximately 3.5 km to the south-east of the town of Alyth, in Perth and Kinross.
The nearest residential premises that also fall within 200 m of the OHL have been identified as ‘Haughend Farm Cottage’ (NSR 92) to the east of the site and ‘Haughend Farm House’ (NSR 93) to the south-east of the site. It is noted that there are small distances from source to receiver for the Proposed Development, with each of these receptors around 200 m from the site boundary. The section of the line has been identified as requiring the triple (AL4)Upas equivalent conductor bundle, therefore cumulative effects have been assessed using the triple (AL4)Upas equivalent conductor bundle. A BS 4142: 2014 assessment of dry noise levels is presented in Table 9-29
Table 9-29: Alyth Substation Dry Cumulative Assessment
Receptor Substation OHL Specific Total BGN Excess Specific
NSR 92 Haughend Farm 17.1 17 20.1 19 1 Cottage
NSR 93 Haughend Farm 14.0 10 15.5 17 -1 House
Cumulative impacts during dry conditions are Low from a BS 4142: 2014 assessment.
A cumulative assessment with the worst case wet OHL noise levels from the cumulative assessment has been conducted in Table 9-30.
Table 9-30: Alyth Mitigated Wet Cumulative Assessment
Receptor Substation OHL Specific Total BGN Excess Specific
NSR 92 Haughend 17.1 42.9 38 5 Farm Cottage 42.9
NSR 93 Haughend 14 41.1 38 3 Farm House 41.1
As demonstrated in the BS 4142: 2014 assessment, during wet conditions the dominant noise sources at the NSRs are the OHL noise and the increase in background noise which make any substation noise redundant. Cumulative effect during wet conditions are unaffected by the substation noise.
Kintore Substation 400 kV Extension A substation noise impact assessment has been conducted for Kintore Substation Extension in Wood report VDN.804648.R.00595
A new 400 kV site is planned as an extension along the boundary of the existing Kintore substation site. Two 400 kV transformers will be brought online at the new site. The noise assessment carried out by Wood helped mitigate the site at the design stage – resulting in the isolated 400 kV site achieving negative excess in terms of a BS 4142: 2014 assessment. This will be attained by the specification of noise enclosures for the transformers. Therefore, there will be no cumulative effect at the NSRs cause by the 400 kV site.
95 VDN.804648.R.005, Kintore 400kV Substation Extension – Noise Impact Assessment, Wood, July 2020 9-22 9.6 Summary The assessment assumes that the noise impact is an introduction of a new source above background noise.
Dry Assessment For the majority of the time (86%) the OHL will be operating under dry conditions. An assessment of dry noise levels shows that for all properties there is of Low impact from the Proposed Development. Cumulative assessments of nearby substations show Low impact from the OHL. Where Significant Adverse impacts are predicted, this is due to the operating substation and not the Proposed Development.
Wet Assessment For a proportion of the year (14%) the OHL will be operating under wet conditions. The highest noise levels generated by an OHL usually occur during light rain when water droplets, collecting on the surface of the conductor, can initiate corona discharge.
The external assessment shows that for a full Twin Totara conductor arrangement there will be a total of 160 Adverse impacts and 59 Significant Adverse impacts for current NSRs. For future NSRs it is predicted a total 720 Adverse impacts, and 205 Significant Adverse impacts.
Internal noise assessments for current receptors with a window open condition predict 65 Adverse impacts and 129 Significant Adverse impacts. For future NSRs, at total of 467 Adverse impacts and 377 Significant Adverse impacts are predicted with a window open condition.
The assessments conclude that extensive design consideration is required for the nearby properties to the OHL to reduce noise emissions to an acceptable level. It has been identified that an alternative conductor type – a triple (AL4)Upas equivalent conductor bundle - offers a reduction of 9 dB under wet conditions. A hybrid approach to the OHL conductor type has been proposed. The design solution eliminates all Significant Adverse impacts.
For current NSRs, residual noise will result in a total of 51 Adverse effects for external noise and 35 Adverse effects for internal noise. The remainder of effects are Low. For future NSRs, residual noise will result in a total of 18 Adverse effects for external noise and 23 Adverse effects for internal noise. The remainder of effects are Low. The solution provided, of a change of conductor type at specific locations, will eliminate all Significant Adverse effects. Where Adverse effects remain, further studies and detailed design will be undertaken to characterise specific noise impacts and further mitigation measures applied as required.
9-23 10 ELECTRIC AND MAGNETIC FIELD EFFECTS
10.1 Introduction Electric and magnetic fields (EMFs), and the associated electromagnetic forces, are a fundamental part of the physical world. Their sources are electric charges (source of the electric field) and the movement of those charges (source of the magnetic field). Electromagnetic forces are partly responsible for the cohesion of material substances and they mediate all the processes of chemistry, including those of life itself. EMFs occur naturally within the body in association with nerve and muscle activity. People are also exposed to the natural magnetic field of the Earth (to which a magnetic compass responds) and natural electric fields in the atmosphere.
This chapter presents an assessment of the changes in EMFs that would result from the Proposed Development. This chapter is not intended to be read as a standalone assessment and reference should be made to the introductory chapters of this EIA Report (Chapters 1-5).
10.2 Assessment Methodology
Scope of the Assessment An assessment of the change in EMF strengths due to the reconductored and reinsulated OHL operating at 400 kV has been undertaken through calculation.
Maximum field strengths were calculated based on the input conditions as stated in the DECC Document “Power Lines: Demonstrating compliance with EMF public exposure guidelines”96. Approximate (worst case) field strengths were calculated for all address locations within a 100 m corridor of the centre line. The results were then aggregated to understand the overall impact, whilst preserving the privacy of individual receptors.
Terminology and Units Electric field strengths are reported in volts per metre (V/m) or kilovolts per metre (kV/m). One kilovolt per metre is one thousand volts per metre. The atmospheric electric field at ground level is normally between 10 – 130 V/m in fine weather and may rise to many thousands of volts per metre during thunderstorms. Magnetic field strengths are reported in units of microtesla (µT) or nanotesla (nT). One nanotesla is one thousandth of a microtesla. Microtesla is used throughout this chapter. The Earth’s field is normally in the same direction, varying in size slowly over time, and is referred to as a static or direct current (DC) field. The Earth has a natural magnetic field, which is approximately 50 µT in the UK. Fields that alternate in their intensity more frequently over time are referred to as alternating current (AC) fields.
96 Department of Energy & Climate Change. Power Lines: Demonstating compliance with EMF public exposure guidelines. A voluntary Code of Practice. March 2012. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/48308/1256-code-practice-emf-public-exp- guidelines.pdf 10-24 All wiring, equipment, and other conductors connected to the electric power system are sources of AC EMFs with frequencies in the extremely low frequency (ELF) range. In the UK and Europe the fundamental power frequency is 50 Hertz (Hz). AC fields add to (or modulate) the Earth's steady natural fields. The strength (or amplitude) of the electric field modulation depends on the voltage of the transmission equipment. As the voltage supplied to power conductors is regulated within a small tolerance, the electric field remains fairly constant whilst equipment is energised. The strength of the magnetic field depends on the current (often referred to as the load) carried by the equipment, which varies according to the demand for power at any given time. Mention of field strengths later in this chapter will mean the root-mean-square amplitude of the power-frequency modulation of the total field, which is the conventional way of expressing these quantities. Unless specified otherwise, all reported values of EMF are referenced to a height of 1 m above ground level in line with the UK’s voluntary Code of Practice (DECC, 2012)97 as referred to by the National Policy Statement for Electricity Networks Infrastructure (EN-5) (DECC, 2011)98. High voltage transmission lines can create electromagnetic emissions over a wide range of frequencies causing radio and television interference. An assessment of radio and television interference was scoped out of this EIA, as detailed in Appendix 4.1: EIA Scoping Report. This section of the EIA Report considers only 50 Hz EMFs.
Extent of the Study Area The assessment of EMFs has been undertaken within a 200 m corridor width (100 m either side of the OHL) centred on the existing OHL Route and along the proposed diverted routes of the OHL at the Alyth and Kintore substations. No diversions are proposed at Fetteresso substation.
Beyond distances of approximately 60 m from most typical UK transmission line configurations, both the average electric and magnetic field levels drop below typical background levels. The dwellings within 100 m of the OHL centre line were identified using Ordnance Survey Address Base Data and manually confirmed by using satellite and street view photography from Google as presented in Chapter 9: Noise and Vibration. Additional consideration was applied to two residential developments: Bertha Park, which at the time of writing is under construction and Almond Valley which is proposed; having consent in principle but no construction work has begun. The location of these developments is illustrated in Figure 5.1: Cumulative Developments.
EMF Exposure Limits In the UK, there are presently no statutory regulations to limit public exposure to power-frequency EMFs, the limits to be considered apply as a matter of government policy. In 2004 Public Health England (PHE), formerly the National Radiological Protection Board (NRPB), provided advice to Government (NRPB, 2004)99 recommending the adoption in the UK of guidelines published in 1998 by the International Commission on Non-Ionizing Radiation Protection (ICNIRP, 1998)100. These guidelines are designed to set conservative exposure levels for the general public to 50 Hz EMFs, and they are endorsed by the UK’s Health Protection Agency, the World Health Organisation, and the UK Government.
97 Department for Energy and Climate Change (DECC, 2012). Power Lines: Demonstrating compliance with EMF public exposure guidelines – a voluntary Code of Practice. March 2012. 98 DECC (2011). National Policy Statement for Electricity Networks Infrastructure (EN-5). July 2011. 99 National Radiological Protection Board (2004). Advice on Limiting Exposure to Electromagnetic Fields (0-300 GHz). Documents of the NRPB, Volume 15 No. 2, 2004. 100 International Commission on Non-Ionizing Radiation Protection (ICNIRP, 1998). Guidelines for limiting exposure to time-varying electric, magnetic and electromagnetic fields (up to 300 GHz). Health Physics 74 (4): 494-522; April 1998. 10-25 In 2010, ICNIRP produced new guidelines which are less conservative; but these do not automatically take effect in the UK. The UK policy for public exposure remains in accordance with 1998 guidelines until Government decide otherwise. Occupational exposure is defined as any exposure experienced by an individual during work related activities, whereas public exposure is defined as any exposure (excluding medical) experienced by a member of the public. The two forms of exposure have been assigned separate exposure limits to keep public exposure as low as reasonably practicable, whilst allowing workers to perform their duties in areas of greater exposure. The limits for occupational exposure are stated in legislation101 and in terms of the EU directive102. These limits are enforceable and should not be exceeded.
A summary of the numerical limits for public and occupational exposure are provided in Table 10-1.
Table 10-1 - Summary of the UK exposure limits
Electric Fields Magnetic Fields
Limits Occupational Public Occupational Public Exposure Exposure Exposure Exposure
Field strengths corresponding to 1 20,000 V/m 9,000 V/m 6000 µT 360 µT the Basic Restriction
Reference Level field strengths, below which no further action is 2 10,000 V/m 5,000 V/m 1000 µT 100 µT necessary, and above which further investigation may be warranted
Line 1 in Table 10-1 gives field strengths that are measurable practically and that are considered to correspond with the Basic Restriction for both occupational and public exposure. Line 2 in Table 10-1 gives Reference Level field strengths, which are yet more conservative values that would, under all normal circumstances, be expected to induce current densities associated with the Basic Restriction. Research (Dimbylow, 2005)103 indicates that, for OHLs, the field strengths quoted as corresponding to the Basic Restriction (Line 1) act as good, if slightly conservative, equivalents to the 1998 ICNIRP Basic Restriction for the general public. For this reason, the Basic Restriction figures in line 1 of Table 10-1 are generally relevant to OHLs rather than the Reference Levels of line 2. The limits specified for general public exposure are lower than those allowed for occupational exposure. Compliance with the general public exposure limits is considered to be required at locations where the public may spend significant time, for example residential buildings; in accordance with the DECC UK voluntary Code of Practice (DECC, 2012).
Baseline Assessment Modelling EMFs have been calculated based upon guidance outlined in the UK Voluntary Code of Practice96. EMF strengths due to OHLs were calculated using standard equations based on fundamental properties and on the assumption of infinitely long straight conductors; and an even terrain.
Electric fields diminish rapidly as the distance from their source increases. They are shielded by most common building materials, trees and fences; although this reduction has not been considered within this assessment and all fields have been assumed to be unperturbed.
101 The Control of Electromagnetic Fields at Work Regulations, 2016 102 European Commission Electromagnetic Fields Directive 2013/35/EU 103 Dimbylow, P. (2005). Development of the female voxel phantom, NAOMI, and its application to calculations of induced current densities and electric fields from applied low frequency magnetic and electric fields. Phys Med Biol. 2005 Mar 21; 50(6): 1047-70. Epub 2005 Feb 23. 10-26 Magnetic fields also diminish rapidly as the distance from their source increases; however, they are not shielded by most common materials. In accordance with industry guidelines, electric field calculations have been made at nominal voltage (initially 275 kV), at minimum design clearance (7.0 m). Magnetic field calculations have been made with winter pre-fault ratings (2070 A) for 2x ACSR Zebra conductors at 75°C which satisfies the requirement to apply the highest rating that can be applied continuously in an intact system. The towers along the length of the OHL Route (Towers 34-559) are of L8 and L2 designs. The tower dimensions of these designs have been considered in the calculations. For the existing and future conditions, circuits will operate with transposed phasing. All OHL diversions into the substations are assumed to be of the same design as the main circuits to which they are connected.
Determining Significance of Effect The acceptability of the prospective field strengths has been judged by comparing the results of the EMF calculations with the UK guidelines as displayed above in Table 10-1.
Sensitive Receptors Sensitive receptors are deemed to be those within 100 m of the OHL. Beyond distances of approximately 60 m from most typical UK transmission line configurations, both the average electric and magnetic field levels drop below typical background levels. A total of 160 address locations were identified within 100 m of the East Coast OHL. Of these 100 are existing and 60 are under construction at the Bertha Park residential development. A further 276 properties are proposed at the Almond Valley residential development; though these are not yet under construction and are subject to change. A total of 436 locations were assessed.
10.3 Baseline Conditions Charts 10-1 and 10-2 below show the EMF profiles for the OHL Route in its existing state. Calculations have been made at 7.0 m (the current minimum clearance) and 12.0 m (typical) clearances.
The calculated maximum EMF strengths directly beneath the line and at several distance measurements can be seen in Table 10-2 and Table 10-3 beneath the plates. The charts and tables show that at all locations; even directly beneath the transmission line conductors that field strengths are lower than the external field limits which correspond to the public exposure basic restriction levels; i.e. 9.0 kV/m for electric fields and 360 µT for magnetic fields.
10-27 Chart 10-1: 275 kV Electric & Magnetic Field Profiles at 7m clearance
Chart 10-2: 275 kV Electric & Magnetic Field Profiles at 12m clearance
The calculated maximum electric and magnetic field strengths due to the existing OHLs operating at 275 kV with maximum balanced phase currents of 2070 A are shown in Table 10-2 and Table 10-3.
Table 10-2 – Baseline Electric Field Strengths at 275 kV
Electric Field Strength (kV/m) at Distance
Transmission Line Clearance (m) Voltage (kV) Max 20 m 40 m 60 m 100 m
East Coast (L8) 7.0 (Min) 275 6.82 0.83 0.15 0.06 0.02
12.0 (Typ) 275 2.68 0.83 0.10 0.05 0.02
10-28 Table 10-3 - Baseline Magnetic Field Strengths at 275 kV
Magnetic Field Strength (µT) at Distance
Transmission Line Clearance (m) Current (A) Max 20 m 40 m 60 m 100 m
East Coast (L8) 7.0 (Min) 2070 42.8 9.9 1.9 0.6 0.2
12.0 (Typ) 2070 19.47 6.9 1.7 0.6 0.2
The baseline maximum field strengths are within the limits set for occupational and public exposure. Table 10-4 shows that all existing and prospective dwellings will experience a peak electric field of less than 1.0 kV/m; with most experiencing a peak field of less than 0.1 kV/m. This indicates that there are no addresses where the electric field from the OHL Route would exceed the public exposure limit of 9.0 kV/m.
Table 10-4 - Distribution of prospective electric field strengths due to the current 275 kV OHLs at address locations within ±100 m from the OHL centre line
Electric Field Strength Range (kV/m) Number of Addresses 0-0.1 0.1-0.32 0.32-1.0 1.0-3.2 3.2+ Existing 82 17 1 0 0 Bertha Park 50 10 0 0 0 Almond Valley 202 72 2 0 0
The distribution of calculated prospective magnetic field strengths at the 436 address locations identified within 100 m, given in Table 10-5, shows that all addresses will experience a peak magnetic field of less than 1.0 µT, with the majority experiencing a peak field of less than 0.1 µT. This indicates that there are no addresses where the magnetic field from the OHL Route would exceed the public exposure limit of 360 µT.
Table 10-5 - Distribution of prospective magnetic field strengths due to the current 275 kV OHLs at address locations within ±100 m from the OHL centre line Magnetic Field Strength Range (µT) Number of Addresses 0-0.3 0.3-1.0 1.0-3.2 3.2-10 10+ Existing 36 31 17 16 0 Bertha Park 25 24 11 0 0 Almond Valley 80 97 88 11 0
10.4 Issues Scoped Out
Construction Consideration of EMFs is not required during the construction phase, however guidance regarding the placement of temporary structures to minimise EMF has been provided and summarised below in Section 10.6 below.
Operation Consideration of EMFs is not expected to affect the maintenance during operation of the Proposed Development.
10-29 10.5 Assessment of Effects, Mitigation and Residual Effects
Construction Phase Design Solutions and Assumptions The existing L8 and L2 towers and proposed conductor system are suitable for 400 kV operation with the appropriate elevation of minimum clearance to ground as required by the Applicant’s internal and industry technical specifications. To meet the clearance requirement conductors can be over tensioned, however for 73 towers, this will not be possible and can only be resolved by tower body / leg extensions. These additional works will require unimpeded access to the existing towers; making it necessary to erect temporary mast structures to temporarily divert the conductors on one circuit during construction works. Description of Effects
Whilst the temporary structures are in place, the transmission line will operate with only one of two circuits energised. This will increase the peak electric strengths around unaffected towers by approximately 5%; and reduce magnetic field by approximately 12% which is not significant. For areas surrounding the affected towers, change in field strengths at the sensitive receptors will be dependent upon the location of the temporary structures, which would be determined by the Principal Contractor(s) with consideration of sensitive receptors. However, so long as the minimum clearance from the diverted conductor to ground is maintained above statutory levels, then the EMF is not likely to exceed public exposure limits and therefore there would not be a significant effect; especially considering such diversions would be temporary.
Mitigation During Construction As no significant effects have been identified, mitigation measures are not required. The contractor will be required to undertake an updated EMF assessment following detailed design, to ensure public exposure limits are not exceeded as a result of any of the temporary diversions. Residual Effect No significant residual effects in relation to EMF have been identified during the construction phase, the line is compliant with public exposure limits.
Operational Phase Description of Effects Charts 10-3 and 10-4 show the electric and magnetic field profiles for the OHL Route at 400 kV operation. Calculations have been made at 7.6 m (minimum design) and 12.0 m (typical) clearances for twin bundle of 498 – Al5 (AAAC Totara) and 8.0 m (minimum design) and 12.0 m (typical) clearances for triple bundle of 362 – Al4 (AAAC Upas) equivalent based on the Applicant’s technical specification. It shall be noted that clearances are measured to geometrical axis of the bundle. At 400 kV, the level of current applied differs due to the conductor replacement. The planned reconductoring will be realised either by twin bundle of 498 – Al5 (AAAC Totara) operating at 90°C (2430A winter pre-fault) or by triple bundle of 362 – Al4 (AAAC Upas) or equivalent operating at 90°C (2835A winter pre-fault).
The calculated maximum electric and magnetic field strengths directly beneath the line and at several distance measurements can be seen in Table 10-6 and Table 10-7, beneath the plates. The data shows the maximum electric field increase by 32%; and that magnetic fields increase by 14%.
10-30 The charts and tables show that at all locations, even directly beneath the transmission line conductors, field strengths would be lower than the external field limits which correspond to the public exposure basic restriction levels; i.e. 9.0 kV/m for electric fields and 360 µT for magnetic fields.
Chart 10-3a: 400 kV Electric & Magnetic Field Profile twin 498-Al5 (Totara) at 7.6m
Chart 10-3b: 400 kV Electric & Magnetic Field Profile triple 362-Al4 (Upas) at 8.0m
10-31 Chart 10-4a: 400 kV Electric & Magnetic Field Profile twin 498-Al5 (Totara) at 12.0m
Chart 10-4b: 400 kV Electric & Magnetic Field Profile triple 362-Al4 (Upas) at 12.0m
Table 10-6a – Future Electric Field Strengths at 400 kV - twin 498-Al5 (Totara)
Electric Field Strength (kV/m) at Distance
Transmission Line Clearance (m) Voltage (kV) Max Field 20 m 40 m 60 m 100 m
East Coast (L8) 7.6 (Min) 400 8.69 1.21 0.21 0.09 0.03
12.0 (Typ) 400 3.91 1.21 0.14 0.07 0.03
Table 10-6b – Future Electric Field Strengths at 400 kV - triple 362-Al4 (Upas)
Electric Field Strength (kV/m) at Distance
Transmission Line Clearance (m) Voltage (kV) Max Field 20 m 40 m 60 m 100 m
East Coast (L8) 8.0 (Min) 400 8.97 1.33 0.22 0.1 0.03
12.0 (Typ) 400 4.38 1.35 0.15 0.07 0.03
10-32 Table 10-7a - Future Magnetic Field Strengths at 400 kV - twin 498-Al5 (Totara)
Magnetic Field Strength (mT) at Distance
Transmission Line Clearance (m) Current (A) Max Field 20 m 40 m 60 m 100 m
East Coast (L8) 7.6 (Min) 2430 44.93 11.1 2.2 0.7 0.2
12.0 (Typ) 2430 22.86 8.1 2.0 0.7 0.2
Table 10-7b - Future Magnetic Field Strengths at 400 kV - triple 362-Al4 (Upas)
Magnetic Field Strength (mT) at Distance
Transmission Line Clearance (m) Current (A) Max Field 20 m 40 m 60 m 100 m
East Coast (L8) 8.0 (Min) 2835 48.94 12.6 2.6 0.9 0.2
12.0 (Typ) 2835 26.67 9.4 2.3 0.8 0.2
Table 10-8 shows that all existing and prospective dwellings will experience a peak electric field of less than 1.0 kV/m; with most experiencing a peak field of less than 0.1 kV/m. This indicates that there are no addresses where the electric field from the OHL Route would exceed the public exposure limit of 9.0 kV/m. As the electric field strengths for twin 498-Al5 (Totara) and triple 362-Al4 (Upas) are very similar, the values within Table 10-8 are valid for both conductor system options.
Table 10-8 - Distribution of prospective electric field strengths due to the upgraded 400 kV OHL at address locations within ±100 m from the OHL centre line Electric Field Strength Range (kV/m) Number of Addresses 0-0.1 0.1-0.32 0.32-1.0 1.0-3.2 3.2+ Existing 64 31 5 0 0 Bertha Park 48 12 0 0 0 Almond Valley 172 100 4 0 0
The distribution of calculated prospective magnetic field strengths, given in Table 10-9, shows that all addresses will experience a peak magnetic field of less than 10 µT, with the majority experiencing a peak field of less than 0.32 µT. This indicates that there are no addresses where the magnetic field from the OHL Route would exceed the public exposure limit of 360 µT. As the magnetic field strengths for twin 498-Al5 (Totara) and triple 362-Al4 (Upas) are very similar, the values within Table 10-9 are valid for both conductor system options.
Table 10-9 - Distribution of prospective magnetic field strengths due to the upgraded 400 kV OHL at address locations within ±100 m from the OHL centre line Magnetic Field Strength Range (µT) Number of Addresses 0-0.3 0.3-1.0 1.0-3.2 3.2-10 10+ Existing 25 38 21 16 0 Bertha Park 19 29 10 2 0 Almond Valley 60 106 90 20 0
The peak electric and magnetic field strengths do increase as a result of the Proposed Development; by up to 2 kV/m for electric field; and by up to 3.6 µT for magnetic fields, however the prospective fields directly beneath the conductors and at all dwellings are all compliant with public exposure basic restriction limits (9.0 kV/m and 360 µT). At dwellings, the average increase is approximately 44% for electric field and 17% for magnetic field in relative terms, however the baseline values are so low that such increases are not considered to constitute a significant change as the level is still below the public exposure threshold.
10-33 Mitigation During Operation
Mitigation would not be necessary because the calculated prospective maximum EMF strengths expected due to the upgraded OHLs fall below the public and occupational exposure limits, even directly beneath the conductors. The Proposed Development would be considered to follow best practice for electricity transmission installations as defined in the UK voluntary Code of Practice96. Residual Effect No significant effects during operation are predicted and therefore no mitigation is proposed.
Cumulative Effects Cumulative effects of the Proposed Developments on other identified developments have been considered where detail for the locations of receptors are known; and where the developments are in close proximity to the Proposed Development. For most other schemes, e.g. utility, infrastructure or industrial development, it is unlikely to be any significant cumulative impact. Future receptors at Perth West Residential Development or Luncarty South Residential and Employment Development have not been considered as their locations are unknown. These future receptors have the potential to be affected by the Proposed Development, however, as stated within this chapter; these effects are not expected to be significant.
There is no statutory or recommended clearance distance which is required based on EMF alone however the developers of other schemes should preserve safe electrical safety clearances and respect the needs of SSE to maintain their assets.
10.6 Summary The baseline peak electric and magnetic fields are 6.82 kV/m and 42.8 µT in the worst case – directly below the line and considering the minimum conductor clearance to ground. With the proposed upgrade to 400 kV operation, these worst-case peak fields increase to 8.97 kV/m and 48.94 µT.
Though dwellings will experience an increase in both fields the baseline levels are so low that these increases are not considered to constitute a significant change. Above all, the EMF calculations show that the EMFs associated with the proposed 400 kV OHL upgrade are within the public and occupational exposure limits and are therefore not significant.
10-34 11 CUMULATIVE EFFECTS
11.1 Introduction As discussed in Chapter 5: Methodology, Section 5.5, two aspects of cumulative assessment have been considered in the EIA Report; in-combination effects and effect interactions. This chapter sets out the findings of the cumulative effects assessment.
11.2 In-Combination Effects In-combination effects are the combined effect of the Proposed Development together with other reasonably foreseeable developments (taking into consideration effects at the stages of site preparation and earthworks, construction and operation). Table 5.2 in Chapter 5: Methodology lists the in-combination developments which have been considered within this report. Each technical topic has considered these developments within the respective chapter (Chapters 6 to 10) and have concluded that no significant cumulative effects have been identified.
11.3 Effect Interactions Cumulative effect interactions are the combined or synergistic effects caused by the combination of a number of effects on a particular receptor, which may collectively cause a more significant effect than individually. The approach to the assessment of effect interactions considers the changes in baseline conditions at common sensitive receptors (i.e. those receptors that have been assessed by more than one technical topic) due to the Proposed Development. The assessment is based upon residual effects only (considered to be effects of minor or greater significance i.e. excluding negligible effects).
An overall assessment of the cumulative effects on identified common sensitive receptors has been made using professional judgement and the technical information provided in Chapters 6-10. Only residual effects with the potential for effect interactions are considered, i.e. where there are common receptors with other distinctly different topics. The following technical topics are therefore excluded from this assessment: · Biodiversity: Ecological receptors are not common receptors and also the ecological assessment includes the impacts from water quality on aquatic receptors; · Cultural heritage: No common receptors; and · Hydrology, Hydrogeology, Geology and Soils: No common receptors with the exception of private water supplies.
Residents in dwellings are the only common receptors identified for this project as they have the potential to be impacted by noise emissions, electric and magnetic fields (EMF) and private water supply impacts. As the EMF assessment has concluded that the electric and magnetic fields associated with the proposed 400 kV OHL upgrade are within the public and occupational exposure limits, there is no potential for effect interactions from this topic. Regarding private water supplies, subject to implementation of the Applicant’s good practice and working control measures, no significant effects are predicted, and effects would be during the construction phase. Noise effects from the assessment are predicted for the operational phase only and would therefore not coincide with potential Private Water Supplies effects. It is therefore concluded that no significant effect interactions are anticipated.
11-1 12 SCHEDULE OF ENVIRONMENTAL MITIGATION
12.1 Introduction The chapters above discuss the potential likely significant effects of the Proposed Development and present additional mitigation measures for managing identified effects where applicable. These additional mitigation measures are listed in Table 12-1: Schedule of Environmental Mitigation and are a commitment of the Applicant.
Embedded mitigation comprising ‘Design Mitigation’ and general ‘Construction Good Practice’ has been incorporated into the description of the Proposed Development; and as such has been assessed as being part of the development proposals. We have included the Applicant’s General Environmental Management Plans (GEMPs) and Species Protection Plan (SPPs) within the schedule of environmental mitigation for completeness. The following mitigation codes are used in this section: · HG – Hydrology, Hydrogeology, Geology and Soils; · BD – Biodiversity and Ornithology; · CH – Cultural Heritage; · NV – Noise and Vibration; · EM – Electric and Magnetic Fields; and · CD – Construction and Design;
12-2 Table 12-12-1 – Schedule of Environmental Mitigation
Ref Description Timing
HG1 Following further investigation of Private Water Supplies (PWS) and consultation with property owners prior to construction, should any PWS be Pre- identified which require protection, specific mitigation will be developed through the CEMP, which will be agreed with SEPA. commencement, Construction HG2 The Pitkeathly Mires Access Method Statement, as presented in Appendix 7.3: Pitkeathly Mires National Vegetation Classification Survey Report, must Construction be fully adhered to.
HG3 With regard to works within areas identified as having a ‘High’ likelihood of flooding on the SEPA Flood map22, construction works would not take place Construction during extreme flood conditions or in floodplain areas that are inundated, or where such conditions are forecast. Careful consideration will be given to any earthwork activities scheduled during the winter period or other periods where saturated soils are likely to occur. HG4 Ground Investigation will be undertaken at locations where ground works are required at locations to be confirmed by the Principal Contractor(s), this Construction will include but not be limited to the four tower extension locations identified in areas of peat and stone access tracks. A Geotechnical Risk Register (GRR) will be prepared and updated as the project progresses, including any identified risk locations in relation to peat instability. HG5 Undertake consultation with Scottish Water prior to construction to identify any Scottish Water assets which require protection. Should any such assets Pre- be identified, specific mitigation measures will be development and incorporated into the CEMP, which will be agreed with SEPA. commencement, Construction HG6 Mitigation measures would be monitored by an Environmental Clerk of Works (ECoW) throughout construction. Should any peat stability risk locations Construction be identified in the GRR, these areas will be monitored as appropriate, prior to and during construction
BD1 Only areas of woodland (including designated and non-designated) that are identified as requiring essential, unavoidable felling will be subject to felling. Pre- Wherever possible, woodland will be retained. commencement, Construction BD2 Pitkeathly Mires SAC Method Statement will be adhered to (included in Volume 4 Appendix 7.3: Pitkeathly Mires National Vegetation Classification Pre- Survey Report). commencement, Construction BD3 Consent for works within Devon Gorge SSSI and Pitkeathly Mires SSSI will be sought from NatureScot prior to commencement of works. Pre- commencement, Construction BD4 There will be no site compounds located within 50 m of designated sites. There will be no refuelling activities within 50 m of designated sites. Pre- commencement, Construction BD5 Dry-stone walls and boundary features will be dismantled by hand between April and October (inclusive) (i.e. during the reptile and amphibian activity Construction season) and in favourable weather conditions and then reinstated upon completion of works.
12-3 Ref Description Timing
BD6 A portion of felled tree stems and limbs will be retained in piles within the operational corridor (subject to landowner agreement) to increase connectivity Construction for small mammals, create habitat resources for invertebrates, reptiles and amphibians, and in turn provide new foraging opportunities for protected species such as badger, pine marten and bats.
BD7 The ECoW will provide on-site guidance. Specifically, this will extend to advising on practices set out in the CEMP, GEMPs, generic and work-specific Pre- SPPs, and method statements to minimise: habitat loss, habitat degradation, disturbance to protected species, spread of invasive non-native species. The commencement, ECoW will monitor any pollution events and advise on the requirement for spill kits or other reactive measures. The ECoW will advise on specific Construction conditions associated with licences and consents, ensuring these are met prior to and during works. ECoW presence will be full-time during works through SACs and SSSIs. The ECoW will deliver pre-construction inductions to all site workers on species likely to be encountered, known resting sites in the works area, and controls in the relevant GEMPs and SPPs which will avoid reckless killing of, or injury to protected species. BD8 Invasive non-native species will be demarcated by the ECoW. No works will occur within 7 m of identified invasive non-native species to prevent further Pre- spread. commencement, Construction BD9 Pre-construction surveys for badger, otter, water vole, pine marten and red squirrel will be undertaken to identify the current use of known and newly Pre- established resting sites along the whole of the OHL Route. Pre-construction survey requirements are set out in the existing SPPs, which state the validity commencement period of survey data for most species as 12 months. This additional mitigation is raised to highlight the essential requirement that pre-construction survey be undertaken due to the lapse in time between baseline assessments and construction, as well as because baseline surveys did not cover the entire OHL Route. These surveys will also identify any protected species licencing requirements, including the potential to close / remove existing resting sites and provide alternative, artificial shelters. It is anticipated that this will merit a planning condition. BD10 Exclusion zones in which no works (including felling) will take place will be established around all badger setts along the OHL Route and proposed Pre- access routes, which will be physically marked out prior to commencement of works. The minimum buffer around entrances of setts in current use will commencement, be 20 m for felling activities and 30 m for all other works. Consideration should be given to the marking of setts, such that attention to their location Construction would not be obvious (i.e. signs should state ’ecological constraint’ or similar). This is additional mitigation distinct from the Badger SPP. BD11 Temporary infrastructure (including site compounds, trackway, working platforms) and watercourse crossings will be micro-sited to avoid the known or Pre- newly established resting sites of protected species. All resting sites of protected species will be retained as far as reasonably possible through micro- commencement, siting. Construction
BD12 Ground-based surveys of trees to be felled within areas of moderate or high suitability to support roosting bats will be undertaken prior to felling. Survey Pre- requirements of low suitability woodland will be determined by the ECoW. Where potential roost features are identified in any tree subject to felling, an commencement, inspection of the potential roost features by an NatureScot-licensed bat surveyor will be undertaken in line with BCT guidelines (aided by aerial rope Construction access if necessary). Further inspections to fully categorise if a roost is present (or likely absent) may be required at the discretion of the NatureScot licensed bat surveyor. These inspections will also identify any licensing and mitigation requirements for bats, such as the precautionary working methods and provision of compensatory roost features (i.e. bat boxes). This additional mitigation is highlighted as it is anticipated to merit a key planning condition.
12-4 Ref Description Timing
BD13 Pre-construction survey for nesting birds will be undertaken to identify the locations of any active nests within, or immediately adjacent to the working Pre- and felling areas along the OHL Route. All pre-construction bird surveys should extend a sufficient distance out from the OHL Route to identify any nest commencement sites which may be within the disturbance range of the species in question (e.g. approximately 50 m for general nesting birds, at least 200 m for declining waders, and at least at least 500 m for rare and vulnerable raptors). BD14 For rare and vulnerable breeding raptors, surveys will be undertaken in areas of potentially suitable habitat in the year prior to works being undertaken in Pre- order to gauge the likelihood of such species posing a constraint. In the unlikely event that any identified nest sites may need to be removed to facilitate commencement, works then this could be done in the intervening non-breeding season so that the risk of constraint during the works is much reduced. The removal of Construction rare and vulnerable breeding raptor nest sites would only be undertaken if absolutely necessary and in consultation with NatureScot, in accordance with the Bird SPP. It may also require the provision of an alternative artificial nest site (e.g. a nesting pole for ospreys). During the year of works, surveys for rare and vulnerable breeding raptors will also be undertaken well ahead of works advancing into each section of the OHL Route so that any new nest sites are identified early and appropriate mitigation measures (as detailed above) can be applied.
BD15 In the event that any confirmed, or suspected active nests are identified within or in close proximity to the works, then a works exclusion zone will be Pre- established around the nest site to a distance commensurate with the disturbance range of the species concerned which will be advised upon by the commencement, ECoW. Works will not be permitted to commence within the exclusion zone until nesting has been completed and the young have fledged, or the ECoW Construction deems, through monitoring and stage of the breeding attempt, that the extent of the exclusion zone may be reduced.
BD16 All construction works taking place within 1 km of Hare Myre, Monk Myre and Stormont Loch SSSI in October will be restricted to the period between Construction one hour after sunrise to one hour before sunset in order to avoid potential disturbance of associated roosting greylag geese when substantial numbers are expected to be present.
BD17 The loss of woodland habitat through permanent forestry loss to widen the operational corridor either side of the OHL Route will be off-set through off Pre- site compensatory planting. While the location(s) of the compensatory planting are not currently known, the trees selected for this planting will be native commencement, species of local provenance. The species mix and planting regime (including planting density, protection measures and establishment monitoring) will be Construction set out in a Compensatory Planting Plan. The compensatory planting excludes felling which would be within the existing 275 kV OHL operational corridor for which consent is already in place to manage trees for operational safety. BD18 All temporary masts with guy cable supports located in ornithologically sensitive areas, such as areas of known raptor activity based on data presented in Pre- Appendices 7.4 and 7.5 and pre-construction surveys will be fitted with bird diverters to increase their visibility to birds and thereby reduce the risk of commencement, collision. Construction
BD19 Pre-construction surveys for beavers will be undertaken following relevant best practice, alongside other pre-construction ecology surveys. The Pre- mitigation hierarchy will be applied to avoid and preserve identified resting sites (including burrows and lodges) in the first instance. Works will primarily commencement, maintain a 30 m buffer around identified resting sites to avoid / reduce potential disturbance impacts. Where this exclusion zone cannot be maintained, Construction or a feature must unavoidably be destroyed as a last resort, NatureScot will be consulted regards to the requirements for a licence. It is anticipated that these mitigation measures will align with the SHE Transmission Beaver SPP (due to be published in early 2021).
12-5 Ref Description Timing
CH1 Further consultation will be undertaken with Historic Environment Scotland (HES) with regards to any potential direct impacts on Designated assets, with Pre- the potential for Scheduled Monument Consent required. commencement, All designated heritage assets listed within Table 8-5 of this EIA Report will be demarcated prior to site works for the Proposed Development to ensure Construction that all access and other works avoid impacting upon these assets. Where such impacts cannot be avoided at Dalbog house (Site 124) and the Battle of Tippermuir Battlefield (Site 344), specific mitigation to reduce the impacts will be undertaken (see mitigation items CH6 and CH7).
CH2 All undesignated heritage assets with surviving upstanding remains, or accurately known locations, listed within Table 8-5 of this EIA Report will be Pre- demarcated prior to site works for the Proposed Development to reduce the impacts on these assets where possible. commencement, Where heritage assets cannot be avoided, the recommendations provided by mitigation item CH4 will be followed. Construction
CH3 Where the Proposed Development requires works over potential sub-surface remains of known heritage assets or any previously undisturbed ground, Pre- temporary surfaces such as protective matting will be used to minimise ground disturbance. commencement, Where ground breaking works are required in previously undeveloped ground, or over potential subsurface remains of known heritage assets, an Construction archaeological watching brief will be undertaken. It is anticipated this would include monitoring of ground breaking works for access tracks where there are no existing roads and any temporary works around the towers. The watching brief would allow for the recording of any known or potentially unknown archaeological remains and will be conducted according to a Written Scheme of Investigation (WSI) that has been agreed with Aberdeenshire Council Archaeology Service (ACAS) and Perth and Kinross Heritage Trust (PKHT). CH4 Where known archaeological assets cannot be avoided and will be directly impacted upon by the Proposed Development, a programme of Pre- archaeological works will be required that is likely to involve earthwork surveys and archaeological excavations conducted prior to construction. These commencement, works will aim to preserve the impacted heritage asset by record. Any archaeological works will be conducted according to a WSI that has been agreed Construction with ACAS and PKHT. CH5 The Principal Contractor(s) will consult with ACAS or PKHT, and HES where relevant, should any discoveries of heritage interest be made during Pre- construction, to enable appropriate measures to be implemented to mitigate potential impacts. commencement, Construction CH6 For access and works at Dalbog House (Site 124) the following will be undertaken: Pre- commencement, · An access route and working area around Tower 372 will be marked out in agreement with HES, to minimise the impact on upstanding Construction remains. · Temporary surfaces such as matting will be used to minimise ground disturbance. · A detailed statement of working methods and mitigation measures will be developed and attached to an application for Scheduled Monument Consent to be made to Scottish Ministers at an appropriate time to allow the reconductoring works to commence on schedule.
12-6 Ref Description Timing
CH7 For access and works within the Registered Battlefield of the Battle of Tippermuir (Site 344), the following mitigation is recommended: Pre- commencement, · All access routes and working areas where ground disturbance is expected will be marked out, in agreement with PKHT, to define the areas Construction due to be impacted upon. · All areas marked out will be subject to archaeological works including a metal detector survey and watching brief, set out within a WSI, and in agreement with PKHT. · Access to Tower 140 along Old Gallows Road should avoid the road where it is unaffected by modern upgrades or utilise matting to preserve one of the key elements of the battlefield. N1 Site specific surveys can be undertaken at NSRs with remaining Adverse impacts. These surveys can be used to inform any requirements for secondary Construction mitigation measures. These further measures could be considered to address issues on a case by case basis, subject to further study and detailed design in advance of construction.
CD1 To achieve mandatory clearance distances as a result of the proposed voltage upgrade approximately 7 ha of permanent forestry loss is anticipated; this Pre- includes an element of resilience felling which would be permitted as part of the existing 275 kV operational corridor, and is therefore an over-estimate. commencement, The more precise area will be recalculated following the completion of an on-going detailed Resilience Survey and a Compensatory Planting Plan will be Construction prepared and agreed with Scottish Forestry. CD2 Adhear to all the GEMPs included in Volume 4 Appendix 3.2: General Environmental Management Plans. Pre- commencement, Construction
CD3 Adhear to all the SPPs, included in Volume 4 Appendix 3.3: Species Protection Plans. Pre- commencement, Construction
12-7