ifa2 eia summary - ifa2interconnector.com€¦ · ifa2 eia summary page 1 contents 1. introduction...
TRANSCRIPT
IFA2EIA SUMMARY
April 2016
IFA2 EIA SUMMARY
Documentreference:
IFA2-ENV-SUM-0001
Version: 1
IFA2 EIA SUMMARY
Page 1
Contents
1. INTRODUCTION 2
2. PROJECT DESCRIPTION 10
3. ENVIRONMENTAL IMPACT ASSESSMENT 26
4. TRANSBOUNDARY EFFECTS 67
5. SUMMARY AND CONCLUSIONS 68
FIGURES
Figure 1.1: overview of the Interconnector route. .............................................................................................. 2
Figure 1.2: Schematic of the proposed interconnector system ......................................................................... 3
Figure 1.3 Main legislation that governs IFA2 project ....................................................................................... 7
Figure 2.1: IFA2 cable route through the English Channel from the UK to France......................................... 11
Figure 2.2: Example of HVDC cable................................................................................................................ 11
Figure 2.3: a) Example of conversion station; b) location (in dot) of the future station, close to existing
electrical substation site................................................................................................................................... 15
Figure 2.4: Example of HVDC converter station ............................................................................................. 15
Figure 2.5: Example of HVDC converter station layout................................................................................... 16
Figure 2.6: Cable route from the French landfall to the French converter station........................................... 20
Figure 2.7: HVDC cable route from the UK landfall to the UK converter station and the HVAC cable route
from the converter station to the connection point .......................................................................................... 20
Figure 2.8: Monks Hill Beach cable landfall..................................................................................................... 21
Figure 2.9: Chilling cable landfall..................................................................................................................... 22
Figure 2.10: Example transition joint bay ........................................................................................................ 22
Figure 2.11: Topography of the eastern Landfall site. ..................................................................................... 23
Figure 2.12: A cable plough in operation......................................................................................................... 24
Figure 2.13: A mechanical trencher................................................................................................................. 24
Figure 2.14: A jetting machine. ........................................................................................................................ 24
Figure 2.15: Rock placement........................................................................................................................... 25
IFA2 EIA SUMMARY
Page 2
1. INTRODUCTION
1.1 The Project
1.1.1 National Grid IFA 2 Limited (National Grid) and the French transmission companyRéseau de Transport d'Électricité (RTE) are jointly developing an electricity linkbetween the United Kingdom and France. This Proposed Development is knownas the IFA2 (Interconnexion France Angleterre 2).
1.1.2 The proposed IFA2 project would be a 1,000 MW High Voltage Direct Current(HVDC) electricity link between the French and British electricity transmissionsystems. It would be a total of approximately 200 km in length and would connectthe central south coast of the UK with the Normandy region of France. Theproposed route and converter station locations for IFA2 are shown in Figure 1.1.
Figure 1.1: overview of the Interconnector route.
1.1.3 The overall proposed Proposed Development would include:
A converter station adjacent to the existing 400kV Tourbe substation inBellengreville which would convert HVDC to High Voltage Alternating Current(HVAC) or vice versa;
Two onshore HVDC cables between the converter station at Tourbe and thelandfall at Merville-Franceville-Plage;
IFA2 EIA SUMMARY
Page 3
Two subsea HVDC cables between landfall at Merville-Franceville-Plage andlandfall at Monks Hill Beach;
Two onshore HVDC cables between the landfall at Monks Hill Beach and theconverter station at Daedalus Airfield;
A converter station in the north east of Daedalus Airfield which would convertHVDC to High Voltage Alternating Current (HVAC) or vice versa;
Up to six onshore HVAC cables between the converter station in the northeast corner of Daedalus Airfield and the landfall at Monks Hill Beach;
Up to six subsea HVAC cables between the landfall at Monks Hill Beach andlandfall at Brownwich, Chilling; and
Up to six onshore HVAC cables between the landfall at Brownwich, Chillingand the NGET substation at Chilling Lane.
1.1.4 HVDC offers the most efficient technology for the bulk import and export ofelectricity over long distances with fewer losses than an AC system. It requires aconverter station at each end of the HVDC link to convert the HVDC power toHigh Voltage Alternating Current (“HVAC”) power for use on the HVAC electricitysystems operated in the UK and France. Figure 1.2 presents a schematicdrawing of the proposed system.
Figure 1.2: Schematic of the proposed interconnector system
1.2 Project Need Case and Benefits
1.2.1 The European Union has recently agreed its 2030 energy and climate framework,which refers to Member States achieving 10% interconnection by 2020 andaiming for 15% by 2030. IFA2 is one of a number of proposed newinterconnectors that would increase the capacity of interconnection to a level of10% and bring benefits to electricity consumers in the UK and France.
1.2.2 Interconnection provides three important benefits to the national energyrequirements as shown below.
IFA2 EIA SUMMARY
Page 4
AFFORDABILITY
Through connection of the UK to France, which in turn connects to the wider Europeanelectricity market, IFA2 should help create downward pressure on wholesale electricity prices.Fluctuations in the wholesale electricity price leading to higher costs of energy in eitherFrance or the UK have the potential to be reduced.
SECURITY OF SUPPLY
Interconnection gives access to a wide range of electricity generation sources and provides ameans to bring in extra supplies from elsewhere when not enough is generated to meet needat that time. This increases our energy security if demand rises or energy generation fallssuddenly in either country.
Complementarity of energy production and consumption in UK and France
SUSTAINABILITY: Supporting the European energy transition
Interconnectors help manage the fact that not all electricity sources can generate consistentlyand predictably and that electricity cannot yet be stored efficiently on a large scale. They dothis by providing a means to pass on surplus energy between countries when too much isgenerated at once to be used domestically. This should make a significant contribution toforging a lower carbon economy both in Great Britain and France.
1.3 Legal Framework
Introduction
1.3.1 In order to install and operate IFA2 various consents and permissions must besecured in line with national and European regulations. In addition to the keyconsents and regulations outlined in this section various temporary permits andconsents will be required during construction in line with local and nationalregulations.
1.3.2 There is one specific regulation that applies to the whole IFA2 project fromconverter station to converter station, the Regulation on guidelines for trans-European energy infrastructure EU 347/2013 (TEN-E Regulation). Under thisregulation the IFA2 project is known as a Project of Common Interest (PCI). TheTEN-E Regulation lays down rules for the timely development of energy networksin European Union Member States and the European Economic Area (EEA) andsets out guidelines for streamlining the permitting processes for major energyinfrastructure projects that contribute to European energy networks. The TEN-ERegulation establishes that PCIs are necessary to take forward EU energynetworks policy and should be given the most rapid consideration in the permittingprocess that is legally possible.
1.3.3 Project promoters of PCI projects (such as National Grid and RTE) are required toundertake certain activities, including written notification of the PCI to the NationalCompetent Authority (in the UK this is the Marine Management Organisation, in
IFA2 EIA SUMMARY
Page 5
France this is the Ministry of Ecology, Sustainable Development, and Energy),establishment of a project website and to carry out at least one pre-applicationpublic consultation on the PCI. Each of these activities has been completed in theUK and France for the IFA2 project.
1.3.4 Although the TEN-E Regulation provides a framework for consenting (orpermitting) the project as a whole, various specific consents are required in theUK and France in order to inform the Comprehensive Decisions that will be madeby the National Competent Authorities in the UK and France. The various keyconsents required are described in the sections below.
EIA Directive
1.3.5 Environmental Impact Assessment (EIA) is a process by which information aboutthe potential environmental effects of a proposed development is collected,evaluated and presented to facilitate consultation and to enable decision makersto take account of these effects (both beneficial and adverse) when determiningwhether or not a project should proceed. EIA seeks to identify the potentialsources of environmental effects during the design of a project and to avoid orminimise adverse effects through appropriate mitigation. It also seeks tocompensate unavoidable effects, for example by providing replacement forenvironmental features which are lost or changed due to development.
1.3.6 The Environmental Impact Assessment (EIA) Directive 2011/92/EU (amendingDirective 85/337/EEC on the assessment of the effects of certain public andprivate projects on the environment) sets out the requirements for EIA which aretransposed into national laws.
1.3.7 Cables installed underground and converter stations are not forms ofdevelopment that are listed under Annex I or II of the EIA Directive 2011/92/EUand therefore EIA is not required for all such projects. However, under FrenchLaw the IFA2 project is considered a development that requires EIA.Furthermore, following the scoping stage for the UK onshore elements of theproject, Fareham Borough Council stated in the Scoping Opinion that thesecomponents of the development require the completion of an EIA. Forconsistency of approach, all elements of the project in the UK and France havebeen subject to comprehensive EIA with a voluntary EIA also being completed forthe UK offshore components of the proposed development.
Habitats Regulations Assessment
1.3.8 Directives 92/43/EEC on the conservation of natural habitats and of the wild faunaand flora (“the Habitats Directive”) and 2009/147/EC on the conservation of wildbirds (“the Birds Directive) form the legal basis for the designation of Natura 2000sites, a network of terrestrial and marine areas designated for conservation
IFA2 EIA SUMMARY
Page 6
importance at a European level. The requirements of these directives arecommon across the EU.
1.3.9 A developer is required by the Habitats Regulations to provide the competentauthority with sufficient information to allow it to consider the potential effects ofthe project on the established (or candidate) Natura 2000 sites in instances wherethe project is not directly associated with the management of the site for natureconservation. This provision of information, the Habitats Regulations Assessment(“HRA”), allows the competent authority to determine whether the proposal couldadversely affect the integrity of the Natura 2000 sites and undertake anAppropriate Assessment if necessary.
1.3.10 In both the UK and France, the Habitats Regulations Assessment (HRA) is beingcarried out with (and using data provided by) the EIA. This will then allow thecompetent authority (MMO offshore and FBC onshore in the UK and DREAL (theDirections régionales de l’environnement, de l’aménagement et du logement)) inFrance to conduct an Appropriate Assessment if required.
1.3.11 In the UK and France, IFA2 either crosses or lies in proximity to a number ofNatura 2000 sites. Those included in the HRA in the UK are 11 sites designatedas Special Areas of Conservation (SACs) and Special Protection Areas (SPAs),one of which is a potential SPA (pSPA). However, only one SPA is actuallycrossed by the proposed cable route, this is in the intertidal area in the UK. InFrance, the HRA considers 4 sites designated as Zone de Protection Spéciale(ZPSs) or Zone Spéciale de Conservation (ZSCs), three of which are crossed bythe proposed cable route and a further site which lies within 5 km of the projectboundary.
Onshore Development UK
1.3.12 The onshore elements of IFA2 and parts of the project to be installed across theintertidal area require Planning Permission under the Town and Country PlanningAct 1990. In support of the application an EIA covering all onshore aspects of theproject has been undertaken. The Environmental Statement (ES) presents thefindings of the EIA and will accompany the Planning Application at the time ofsubmission. The Local Planning Authority (LPA) for the onshore consentapplication for IFA2 is Fareham Borough Council.
1.3.13 In addition to the EIA, a Habitats Regulations Assessment (“HRA”) will also becarried out with the EIA. This will then allow the competent authority (in this casethe Marine Management Organisation or Fareham Borough Council although weunderstand the MMO will be the lead competent authority in carrying out theHRA.) to conduct an Appropriate Assessment if required. This process issummarised above in the HRA sections.
IFA2 EIA SUMMARY
Page 7
Offshore Development UK
1.3.14 A Marine Licence (under the Marine and Coastal Access Act 2009) is required forthe offshore components of the Proposed Development as follows:
The Direct Current (“DC”) cables from the intertidal area out to the 12nautical mile limit; and
The parts of the Alternating Current (“AC”) cable loop from the intertidal areaclose to the converter station location at Daedalus airfield and the intertidalarea close to the new substation at Chilling.
1.3.15 The offshore volume of the EIA covers the project within UK waters from theintertidal area to the median line separating French and UK waters.
1.3.16 A HRA for the offshore components was undertaken jointly with the onshorecomponents. The approach to this assessment is detailed above.
Development France
Figure 1.3 Main legislation that governs IFA2 project
IFA2 EIA SUMMARY
Page 8
1.3.17 Two key pieces of legislation govern offshore projects in French waters:
The CGPPP (Code Général de la Propriété des Personnes Publiques) whichconcerns the use of public areas. Any use of the public maritime Domainrequires an authorization, named “concession d’utilisation du domaine publicmaritime”. The “Loi sur l’eau et le Milieu Aquatiques” (“LEMA”), 2006,requires an authorisation (LSE) for offshore projects with a value in excess of1.900.000€. Its objective is to control development either on or offshore andit’s associated environmental effects on aquatic environments. EIA and aninstallation and decommissioning method statement are the keyrequirements of an application for consent under this law. A HRA in respectof effects on Natura 2000 sites designated for conservation importance isalso a requirement and this process occurs in parallel with the EIA for theoffshore components of the project (see above sections on HRA).
1.3.18 Other legislative frameworks are in development and have been taken intoaccount in the EIA work in France. The Biodiversity Law requires developers totake measures to maintain biodiversity alongside their projects rather thanprohibiting certain aspects of projects. In addition EU Directive 2008/56/CE forthe marine environment, will oblige every European country to issue a PAMM(Action Plan for the Marine Environment).
1.3.19 In respect of state and public consents, consultations have taken place withmaritime administrations, military authorities, the public finance department andlocal authorities to present the project and gain feedback and comments. A publicenquiry is also a mandatory requirement to be undertaken as part of theinstruction of the DUP, CUDPM and LSE.
1.3.20 Onshore cable laying in France is governed by regional plans (“Schemes”), theEnvironmental Code and other established process for civil work on land. Allrelevant Schemes appropriate to the proposed development were identifiedduring the EIA process. All development on land must adhere to theEnvironmental Code which constitutes the guidelines for EIA. Specific elementsof the code relevant to the proposed development, such as human health,economic and cultural effects, Natura 2000 sites and La Loi sur l’eau (whichconcerns potential impact to water quality and resources) were identified duringthe EIA process and the requirements were followed.
1.3.21 Cable laying operations are also governed by an established process for civilwork which is controlled by the Town Planning Code. RTE is required to ask localauthorities and local landlords for land agreements and/or leases, but is notobliged to obtain a Building Permit for electrical connections. A Building Permitwill however be required for the converter station.
IFA2 EIA SUMMARY
Page 9
1.4 Consultation
1.4.1 National Grid and RTE recognise the potential impact development can have onlocal communities and believe that local people should be involved in helpingshape the environment in which they live. Guidance from local and nationalgovernment reinforces the importance of consultation in the developmentprocess.
1.4.2 The TEN-E Regulation specifies requirements for setting out a programme ofconsultation with local communities, marine stakeholders and regulators.Therefore public exhibitions and stakeholder meetings have been undertaken inthe UK and France in line with the TEN-E Regulation. Public meetings have beenadvertised on the RTE and National Grid websites and in local newspaperstogether with leaflets distributed to ensure that all people potentially impacted bythe Proposed Development have the opportunity to attend and submit feedback.Feedback has been documented in meeting minutes and consultation reports andtaken into account in design of the project and defining mitigation for anyenvironmental effects.
1.4.3 The pre-application consultation process in France is known as “La Concertation”and a schematic diagram showing how this in relation to the applicationpreparation and submission is shown below.
Figure 2.4 Pre-application consultation process France
1.4.4 Details of the public consultation undertaken in the UK and France and feedbackreceived are available at http://ifa2.nationalgrid.com/downloads/ and www.rte-projet-ifa2.fr.
IFA2 EIA SUMMARY
Page 10
2. PROJECT DESCRIPTION
2.1 Introduction
2.1.1 This section details the specific elements that make up the ProposedDevelopment in the UK and France and alternative development options andlocations that have been considered. Installation methods are outlined below andexamples of the type of installation and equipment are also provided.
2.1.2 The IFA2 interconnector will connect into the GB transmission system at a new400kV substation to be constructed by National Grid Electricity Transmission plc(NGET) at the existing Chilling sealing end compound in Hampshire, and into theFrench transmission system at the existing Tourbe 400kV substation inNormandy, France (as shown in Figure 2.1).
2.1.3 The AC electricity of the “sending” country is converted to DC electricity at theconverter stations and then transmitted to the “receiving” country’s converterstation, where it is converted back to AC and supplied to the receivingtransmission system. The interconnector is reversible and capable of importingand exporting electricity depending on requirements at any given time.
2.1.4 The IFA2 project consists of two HVDC converter stations of similar construction,one sited in each country. The table below provides a summary of the mainelements of the Proposed Development.
Table 2.1: Key project Information
Power Capacity 1000 MW (received)Planned Final Investment
Decision dateQ4 2016
Interconnector RouteLength
Total Route: ~240km
DC Route : ~230kmPlanned Energisation &
Commissioning dateQ4 2019/20
GB Connection LocationChilling 400kV substation,Hampshire
Planned Trial Operations date Q4 2020
GB HVDC ConverterLocation
Daedalus airfield, Lee-on-the-Solent, Hampshire
Planned 1st full year ofcommercial operations
2021
French ConnectionLocation
Tourbe 400kV substation,Bellengreville, Normandy
HVDC converter technologyVoltage Source Converter(VSC)
French HVDC ConverterLocation
Adjacent to Tourbe 400kVsubstation, Bellengreville,Normandy
HVDC cable technology MIND / XLPE
HVDC operating Voltage <400 kV HVDC configuration Symmetrical Monopole
IFA2 EIA SUMMARY
Page 11
Figure 2.1: IFA2 cable route through the English Channel from the UK to France
2.1.5 The HVDC converters are connected by 2 HVDC cables – underground andsubsea along a defined cable route. Typically, these cables are approximately15cm in diameter. In the marine area (beyond the intertidal area) the HVDCcables will be bundled and installed together.
Figure 2.2: Example of HVDC cable
IFA2 EIA SUMMARY
Page 12
2.1.6 HVAC cables connect each converter station to the transmission networksubstations. In the UK, part of the AC cable route is located offshore, due toonshore constraints.
2.1.7 In the UK, the development of the transmission network substation at Chilling isthe responsibility of National Grid Electricity Transmission (NGET) and is notwithin the scope of the project and this summary document.
2.2 Alternatives
2.2.1 IFA2 is a specific electrical link between the UK and France. The objective of thelink is to provide electricity interconnection between the two countries.
2.2.2 Following assessment of alternative options for connection to the electricaltransmission systems in the UK and France connection points at Chilling andTourbes were identified. Various marine route and landfall alternatives have beenconsidered taking into account ground conditions and geology, ecologicalsensitivities and protected sites, marine activities, and economics. Based onanalysis of data and consultation a marine route between Brownwich nearChilling, in the UK and Merville-Franceville-Plage in France has been identified.
2.2.3 Suitability of the converter station sites is also dependent on the feasibility oflanding and routing HVDC cables from the sea to the converter station and HVACcables to the transmission connection points. Options for routing of both theHVDC cables to the converter stations and HVAC cables from the converterstation to the substation connection points in the UK and France have beenconsidered and the preferred options, and alternatives, have been discussed withthe public and other stakeholders at public exhibitions and meetings.
2.2.4 IFA2 has to connect to the existing electricity networks in both countries. As such,the search for grid connections has to be geographically compatible. In GreatBritain, this involves agreeing the connection point to the existing GB network withNGET. The process followed to select the Chilling site as the connection point forIFA2 is the same as that followed by all proposed developments requiring aconnection e.g. interconnectors, offshore wind projects.
2.2.5 Three areas of consideration were identified for potential connection to the Britishgrid along the south - Devon and Dorset, Hampshire and West Sussex and Kentand East Sussex. Discussions with both NGET and RTE indicated thatconnections around the narrowest point of The English Channel (from the Kentand East Sussex area and the North East of France) would not be suitable giventhe existing (IFA, BritNed) and proposed interconnectors (Nemo, ElecLink) in thisarea which bring network management issues in Great Britain and France relatingto the flow of power in both directions on multiple HVDC links.
2.2.6 The search was then focused on the West Sussex, Hampshire and Dorset area.The search included consideration of: the proximity of existing National Gridinfrastructure to the coast; environmental designations; planning policy; technicalconstraints to routeing and siting of a feasible connection to the existing grid;
IFA2 EIA SUMMARY
Page 13
potential landfall sites; HVDC and HVAC connections; and land for a converterstation site.
2.2.7 The process of finding an available site for the converter station in the UK whichmet the project requirements began in 2010. A range of factors were considered:the site and cable route have to be fit for purpose and, technically andeconomically viable, as well as being environmentally acceptable. DaedalusAirfield was determined to be the best available option to locate the converterstation.
2.2.8 For the HVAC connection, options for routeing the cables from the converterstation to the connection point on the grid were identified. There are significantconstraints on routeing new cables in the area between Daedalus and Chilling.There are a number of designated sites of environmental interest in this area,open space safeguarded as Strategic Gap by Fareham Borough Council, and arange of other proposed and consented developments including the StubbingtonBypass. These constraints meant that routeing cables overland between theconverter station and connection point could have a significant environmentalimpact. Routeing the AC cables offshore provided a viable alternative. Havingconsidered potential effects and views of local stakeholders, IFA2 decided to takeforward the cable route from the converter station at Daedalus to the connectionpoint on the grid at Chilling via an offshore route.
2.2.9 The main technical characteristics of the interconnector project were determinedbased upon the outcomes of feasibility studies conducted in 2012 and 2013.These studies were conducted based on the following criteria:
Firstly, a converter station of appropriate dimensions to accommodate apermanent capacity of 1 GW at all times of the year (thus the existing400,000 volt Tourbe electrical station has been identified as an appropriateconnection point);
Secondly, an appropriate landfall point for the interconnector which issufficiently close to the converter station has been sought. This involvedconsideration of the following:
Research and consideration of the characteristics the coastline includingmorphology, access, and level of urbanisation;
Avoidance of designated coastal areas;
Width of access in relation to the use of HDD in order to preserve thedunes;
Available land of a sufficient size to enable landfall construction.
IFA2 EIA SUMMARY
Page 14
2.2.10 The IFA2 project is located east of the Orne Estuary, between Merville-Francevilleand Hôme-Varaville. Two landfall options were identified and assessed (seeFigure 25).
Figure 3 : Location of landing options on the French coast
2.2.11 Following assessment and comparison, the eastern landfall emerged as the mostsuitable for the following reasons:
The level of available surface area will facilitate management of the site;
The duration of work on the traffic route RD 514 and the inconvenience to
traffic during laying of ducts which will be significantly lower at this landfall
point;
The route is shorter, which results in a lower construction cost; and
The narrower width of the dune belt reduces the required amount of HDD
to be undertaken.
2.2.12 The converter station, required for the transition from direct current to alternatingcurrent, will be built close to the existing Tourbe substation. This choice avoidsthe construction of a new substation and additional consumption of agriculturalland.
Given these constraints, the converter station site is proposed to be located on
the north side of the existing substation. The area available is sufficient and it
avoids:
Consumption of agricultural land (as the land to be used was formerly
devoted to a now discontinued operation); and
Woodland areas.
2.2.13 This location also offers the best compromise in relation to distance from housingof Secqueville and La Hogue. Finally, the converter station will benefit from goodlandscape integration insofar as the site is bordered by woodland.
IFA2 EIA SUMMARY
Page 15
2.3 Converter Stations
2.3.1 Two converter stations - one near Lee on Solent in the UK at Daedalus and oneadjacent to the existing 400kV substation at Tourbe in Bellengreville - will berequired for the project. These converter stations would convert HVAC to HVDCand vice versa. Figures 2.3 and 2.7 below show the proposed converter stationlocations.
Figure 2.3: a) Example of conversion station; b) location (in dot) of the future station, close to existingelectrical substation site.
2.3.2 A converter station includes equipment similar to a typical electrical substation, aswell as converter transformers, a valve hall which houses electronic devices thatconverts the AC waveform to DC and vice versa and a control room. It typicallycomprises a collection of steel-framed buildings with cladding. All of the buildingsand equipment would all be contained within a securely fenced compound.Figures 2.4 and 2.5 below provide a photograph of an existing converter stationfor a similar project and an indicative illustrative example of the converter stationlayout. The detailed design will be carried out by the contractor that will beappointed to supply and build the converter station.
Figure 2.4: Example of HVDC converter station
IFA2 EIA SUMMARY
Page 16
Figure 2.5: Example of HVDC converter station layout
2.3.3 Each converter station requires 4 – 5 hectares of land and the buildings wouldoccupy an area approximately 120 m by 200 m. This would comprise a collectionof buildings up to 22 m in height. The valve hall would be the largest building 120m by 40 m, with a maximum height of 22 m, and would be adjoined by an ACreactor building 60 m by 50 m, and a series of smaller structures measuring 40 mby 15 m. An additional lay down and a temporary construction area measuring upto approximately 3 hectares would be required, which would be fully reinstatedfollowing construction. The converter station would be designed for a 40 yearlifespan.
2.3.4 On the French side, the converter station will be built on a 5 hectare piece of land.
2.3.5 In France the equipment will not all be indoors. Various environmental factors aretaken into account for converter design – such as pollution due to coastal salinity,
IFA2 EIA SUMMARY
Page 17
visual impact, and noise. This means that the converter station designs in UK andFrance can be different to meet the different environmental conditions.
2.3.6 In the UK, the converter station is located close to the coast, adjacent to anairfield and close to residential areas – which drives a more compact layout withequipment located indoors in buildings.
2.3.7 The north of the airfield (where the proposed converter station site in the UK islocated), comprising the land beyond the taxiways and south of the B334 GosportRoad, currently comprises grassed areas and land in arable agriculture. There isno public access to this land. Part of this land is safeguarded by FBC policy(DSP12) for the provision of public open space. FBC has subsequently publishedthe Daedalus Vision document, which sets out a different proposal for land to beused as open space for the benefit of the local community.
2.3.8 The proposed converter station site includes a small proportion of the landsafeguarded for public open space and the Proposed Development thereforeincludes compensatory open space provision as well as landscaping. To assist inscreening the converter station, landscaping will take the form of mounding andnative planting. The final design of the Open Space will be determined at a laterdate in consultation with landowners, FBC, the Airfield operator and other keystakeholders.
2.3.9 The works for the Open Space would involve earth works for mounding andcreating footpaths and cycleways, grassland planting and some tree planting. Nosoil would be transported to or from the site in the earth works. For the purposesof the environmental impact assessment, a ‘reasonable worst-case’ scenario isassumed for the Open Space, as follows. When considering potential adverseeffects of the open space, for example the amount of construction traffic whichmay be present, it has been assumed that all of the Open Space will bedelivered. When considering potential beneficial effects such as screening ofparts of the development by planting, it has been assumed that only the moundingand planting immediately north and west of the proposed converter station andthe planting described immediately west of Broom Way and south of GosportRoad would be delivered.
2.3.10 Construction of each converter station would take three years from site clearanceand establishment through to completion of commissioning and is expected tocommence in late 2017.
IFA2 EIA SUMMARY
Page 18
2.4 Onshore Cables and Cable Landfalls
2.4.1 HVDC cables will be installed between each converter station and transition jointbays that will be located close the landfall areas. The subsea cables will be joinedto the onshore cables in these joint bays. In the UK the grid connection point atChilling is located approximately 5km away from the converter station location.To connect the converter station to the connection point up to six offshore HVACcables will be installed. The HVAC cables route follows the HVDC cable routefrom the converter station then proceeds offshore for approximately 5km beforethe cables reach landfall at Brownwich, Chilling. Onshore HVAC cables will thenconnect a transition joint bay to the connection point.
2.4.2 The Figures below show the proposed cable routes between the converterstations and the coast where the onshore cables are joined to the offshore cablesin both France and the UK. .
IFA2 EIA SUMMARY
Page 19
IFA2 EIA SUMMARY
Page 20
Figure 2.6: Cable route from the French landfall to the French converter station.
Figure 2.7: HVDC cable route from the UK landfall to the UK converter station and the HVAC cable routefrom the converter station to the connection point
2.4.3 In the UK the proposal is to install the HVDC and HVAC cables alongside therunway of the Daedalus airfield. At the end of the runway there are variousoptions for cable installation between this point and the landfall area at the beachincluding horizontal directional drilling (HDD) out to sea and pipe jacking to avoidopen cut trenching across a road. In the intertidal area the cables could beinstalled via HDD techniques, traditional open cut trenching and burial of thecables using excavators or installation of ducts (also using open cut trenching)which the cables will be pulled through. This last method would mean that theducts could be installed and the area reinstated before the marine cables arebrought ashore. Figure 2.8 below provides an overview of options beingconsidered for the cable installation at the landfall.
IFA2 EIA SUMMARY
Page 21
Figure 2.8: Monks Hill Beach cable landfall
2.4.4 At Brownwich, Chilling, conduits will be installed between the land and sea usingHDD techniques to avoid an area of coastal erosion and prevent disturbance ofprotected seagrass beds. Figure 2.9 shows the offshore HVAC landfall atBrownwich, Chilling (Figure 2.7 above shows the onshore HVAC cable route tothe connect point at Chilling).
IFA2 EIA SUMMARY
Page 22
Figure 2.9: Chilling cable landfall
2.4.5 Figure 2.10 below gives an example of a transition joint bay. Once the cables areinstalled and jointed together the joint bay is closed and the ground abovereinstated.
Figure 2.10: Example transition joint bay
IFA2 EIA SUMMARY
Page 23
2.4.6 In France the HVDC cables will be installed across the beach area usingtraditional land based excavators and marine burial equipment in the area aroundthe low water mark. The technique of HDD will be used to install conduits underthe sand dunes which are located above the high water mark at Merville-Franceville-Plage and the HVDC cables will be pulled through these conduits.This installation technique ensures the sand dunes will not be disturbed.
Figure 2.11: Topography of the eastern Landfall site.
2.4.7 Installation of the onshore cables and marine cables at the landfalls will take placeover a period of several months to complete and is expected to be undertaken inseveral phases (e.g. preparatory works, onshore cable installation, installation ofHDD conduits or ducts in the intertidal area, construction of the transition jointbays, pull in and burial of the marine cables etc) which may run in parallel.Timescales for work in the vicinity of the beaches will be minimised to reducedisruption to beach use as far as is possible.
2.5 Offshore Cables
2.5.1 The proposed offshore HVDC cables will run between the landfall at Merville-Franceville-Plage and landfall at Monks Hill Beach as illustrated in Figure 2.1above. The proposed offshore HVAC cables in the UK will run from Monks HillBeach to Brownwich, Chilling as shown in Figure 2.7 above.
2.5.2 Trenching, lay and burial of marine cables could either be a simultaneous processor separate processes for the HVAC and HVDC cables whereby the cables maybe laid on the seabed with burial occurring by another vessel as a furtheroperation. Prior to laying the cable, a pre-lay grapnel run will be performed and
IFA2 EIA SUMMARY
Page 24
out of service cables and debris will be cleared. These processes aresummarised in Table 2.2 below.
Table 2.2: Summary of the required stages of subsea cable installation for IFA2.
Aspect Footprint Equipment
Pre-lay grapnel run Prior to cable laying and burial a grapnel will be pulled through theseabed to clear any debris present. The grapnel will beapproximately 1 m wide.
Grapnel run vessel
Grapnel equipment
Support vessel(s)
Clearance of out ofservice cables anddebris
Out of service cables will be lifted and cut 100m either side of thecable route.
Clearance works vesselCutting equipment.Support vessel(s)
Shallow water(intertidal zone to<10 m waterdepths) cableinstallation
Cable laying or burial vessels may need to ground out or jack upin shallow waters.Anchors may be used to maintain vessel position – deployedapprox 100 m from vessel.Cables will be buried to approx 1-3 m.Footprint of burial machine up to 15 m.Footprint of trench approx 1-5 m.HVDC Cables to be bundled in a single trench.Up to 6 HVAC cables to be installed.
Cable laying barge or jack up bargeBurial vessel and associated burialequipment (e.g. plough/ mechanicaltrencher/jetting machine)Flotation equipmentSupport vessel(s)
Divers
Offshore (>10 mwater depth) cableinstallation
Anchors or dynamic positioning may be used to maintain vesselposition – anchors deployed approx 100 m from vessel.Cables will be buried to approx 1-2 m.Footprint of burial machine up to 15 m.Footprint of trench approx 1-5 m.
HVDC Cables to be bundled in a single trench.
Cable laying barge/vesselCable burial barge/vesselBurial vessel and associated burialequipment (plough/mechanicaltrencher/jetting machine)
Support vessel(s)
2.5.3 Offshore installation will take place over several laying campaigns (preferably insummer months where the weather conditions are likely to be more suitable foroffshore works), over a maximum period of 3 years. As it is not possible to loadthe whole HVDC cable length on board a laying vessel, cable laying will likelyconsist of 4 or 5 sections of cable with joints between each section rather than acontinuous cable run. The HVDC cables will also be bundled and installed as onecable bundle.
2.5.4 Cable burial could be undertaken by three key types of equipment – a plough, amechanical trencher or a jetting machine (see Figures 2.12 – 2.14 below).
Figure 2.12: A cable ploughin operation.
Figure 2.13: A mechanicaltrencher.
Figure 2.14: A jettingmachine.
IFA2 EIA SUMMARY
Page 25
2.5.5 Ploughing involves a large mechanical plough being lowered from a cable layingbarge or vessel to sit on the seabed. As the barge moves forward, the plough istowed behind the vessel and adjustable skids on the plough are gradually raised,allowing the plough share to create a trench of the required depth. The width ofthe trench is typically 500 mm and the cable is laid simultaneously with the liftedseabed being to some extent deposited in its original position to cover the cable.There are modifications to this technique which may be used, such as the use ofa rock cutting plough or a vibrating share plough, both of which are used in areaswhere the substrate is very hard and challenging to trench using other methods.
2.5.6 Mechanical trenching creates a trench using a series of metal picks mounted on achain or a cutting wheel. As the chain/wheel rotates the substrate is excavated bythe picks and removed by the rotation of the mechanism. This technique isgenerally used to excavate stiff to hard substrates. Some mechanical trenchersuse a combination of mechanical trenching and jetting modification, and theygenerally rely on tracked propulsion systems to move forwards rather than towing.
2.5.7 Jetting machines can either be free-flying (with neutral buoyancy manoeuvred bymultiple thrusters) or tracked vehicles which are driven forwards using integralcaterpillar tracks. Jetting creates a trench by directing a forwards-facing highpressure jet of water at the trench face through nozzles set into adjustable legswhich stand aside the cable and create the trench below. The water jet fluidisessandy substrates after which the cable naturally lowers into the trench, often usinga depressor, and the fluidised sediment settles over the installed cable. In claysediments, the water jet cuts through the clay creating a slot-shaped trench intowhich the cable lowers. Spoil is carried out of the trench by the flow of water.
2.5.8 In some areas of hard sediments where there is rock close to the seabed surfacerock it may not be possible to bury the cables. In such locations it is anticipatedthat rock placement will be used to protect the cables, although other possiblemethods include concrete mattresses/grout bagged solutions.
Figure 2.15: Rock placement
IFA2 EIA SUMMARY
Page 26
3. ENVIRONMENTAL IMPACT ASSESSMENT
3.1 UK Onshore EIA
Introduction
3.1.1 This section provides a summary of the UK Onshore EIA which is currently beingfinalised. It is important to note that in the UK the onshore EIA covers the areadown to low water and the offshore EIA covers the area up to high water.Therefore both the onshore and offshore EIA cover effects on the intertidal areawhere relevant.
Surveys Undertaken
3.1.2 Various surveys have been undertaken to inform the onshore EIA includingwintering and breeding bird surveys, habitat surveys, protected species surveysand noise surveys. Surveys have been undertaken in line with relevant guidanceand regulations and feedback from stakeholders.
Approach to Impact Assessment and Key Findings
Ecology
3.1.3 Within the Ecology Chapter of the Environmental Statement the effects onecology arising from the Proposed Development have been fully assessed in linewith the latest UK industry standards (Chartered Institute of Ecology andEnvironmental Management, Guidelines for Ecological Impact Assessment in theUK and Ireland: Terrestrial, Freshwater and Coastal, 2nd edition, January2016). The Ecological Impact Assessment (EcIA) covered habitats and speciesidentified in UK and European legislation, UK and local planning policies and bystatutory bodies during consultation.
3.1.4 Baseline information to inform the EcIA was gathered using data searches,consultation with relevant environmental bodies and field surveys (includinghabitat surveys and faunal surveys). The onshore EcIA also took account of theassessment for the offshore elements of the project where relevant with both
IFA2 EIA SUMMARY
Page 27
onshore and offshore assessments considering the intertidal zone to ensure allreceptors and effects were covered.
3.1.5 The EcIA has concluded that all effects on ecological receptors resulting from theProposed Development1 (alone and cumulatively with other projects and plans)can be avoided or reduced to only locally significant levels. Where effects onprotected species have been identified, the Proposed Development has beendesigned either to avoid licensable works or incorporate mitigation measures toensure works will meet the standards required to allow any necessary licenses tobe issued (by UK Government bodies).
3.1.6 The Proposed Development is in the vicinity of several Natura 2000 and Ramsarsites and as such has been subject to a report to inform a Habitats RegulationAssessment (HRA) including Stage 1 Screening Assessment and Stage 2Appropriate Assessment. The Stage 2 assessment focused on the Solent andSouthampton Water SPA and Ramsar sites, Portsmouth Harbour SPA andRamsar sites, Chichester and Langstone Harbours SPA and Ramsar sites andthe River Itchen SAC. In relation to the coastal SPA/Ramsar sites, Stage 2 workfocussed on assessing potential disturbance effects on wintering birds, sea-grassbeds and other coastal habitats associated with shallow coastal waters. Inrelation to the River Itchen SAC, Stage 2 work focussed on noise and vibrationeffects on Atlantic salmon.
3.1.7 Potential disturbance of wintering birds was reduced to acceptable levels byprogramming works at Chilling to avoid the winter months. Other mitigationmeasures were also formulated to protect SPA birds on migration in Septemberand April. Potential effects on sea-grass were avoided by moving the location ofHDD drilling works away from this sensitive habitat. The Stage 2 AppropriateAssessment concluded that after taking mitigation measures into account, theProposed Development would have no likely significant adverse effects on Natura2000 or Ramsar sites (alone or in-combination with other projects and plans). TheHRA work was undertaken in consultation with the UK Government (NaturalEngland). Accordingly, the EcIA and HRA assessments conclude that there areno significant ecological effects predicted to arise from the ProposedDevelopment.
1 References to the “Proposed Development” in section 3.1 are to the UK onshore and intertidal elements of the IFA2
project.
IFA2 EIA SUMMARY
Page 28
Landscape and Views
3.1.8 The method for the landscape and visual assessment is based on the guidancecontained in the ‘Guidelines for Landscape and Visual Impact Assessment - ThirdEdition’, Landscape Institute/Institute of Environmental Management andAssessment, 2013 (GLVIA3). There are five stages to the method of assessmentof landscape effects as detailed in GLVIA3 Volume 5. These comprise:scope; establishing the landscape baseline; predicting and describing landscapeeffects; assessing the significance of landscape effects; and judging the overallsignificance of landscape effects.
3.1.9 Landscape effects are mainly assessed to be of a minor adverse significance.However, during construction the short-term effect on the coastal plain landscapeof the installation of the Monks Hill Beach Landfall and cables and works toconstruct the converter station would be of moderate to minor adversesignificance.
3.1.10 During operation and in the short, medium and long-term the converter stationwould introduce large-scale buildings into the northeast part of DaedalusAirfield. It is recognised that the converter station development would be larger inscale than any existing development at the Daedalus airfield.
3.1.11 However the airfield and surrounding coastal plain already forms part of an urbanfringe landscape, which contains a range of developments, including some largebuildings around the periphery of the airfield. The proposed converter stationwould be close to mature woodland, which would help to screen the developmentin the landscape and additional mitigation proposals would extend the woodedand enclosed nature of the Alver Valley into the northeast corner of the airfield.Once established, this mitigation would provide effective partial screening andsoftening of the built converter station development, reducing its influence on thewider landscape. It was concluded that the operation of the converter station inthe northeast part of Daedalus Airfield would give rise to a moderate to minoradverse residual significance of effect on the landscape in the long-term.
3.1.12 The installation of the Chilling Landfall and Cables would give rise to short-termmoderate adverse significance of effects on the local coastal plain landscape.Following the reinstatement of the cable swathe, the operation of the cableswould give rise to an overall negligible residual significance of effect. A minoradverse residual significance of effect has been assessed in localised areaswhere the underground cables route would result in permanent tree removal.
3.1.13 The likely visual effects are generally assessed to be of minor adverse ornegligible significance, during construction, on completion and in the short term(0-5 years) and medium term (5-10 years), and in the long term (after 15 years)with additional mitigation. However, some views in the vicinity of the converterstation would experience adverse effects of moderate or major to moderatesignificance in the short-to-medium term. In the long term, these effects would bereduced to minor adverse for all but two views, which would experience residualmoderate adverse effects.
IFA2 EIA SUMMARY
Page 29
3.1.14 Depending on the construction methodology used for cable landfalls, in the worstcase, two views would experience moderate adverse effects during theconstruction phase only.
Historic Environment
3.1.15 The scope of the assessment of effects on the historic environment comprised thefollowing:
A review of whether any protected features and archaeological interestswere likely to be impacted by the Proposed Development;
A review of designated heritage assets and the contribution made by settingthe significance of designated and non-designated heritage assets within thestudy area;
A site walkover of the Chilling and Daedalus cable routes and converterstation;
Consultation with relevant stakeholders; and
An assessment of the potential effects and identification of any mitigationmeasures that might be required.
3.1.16 The assessment concludes that the construction of the landfalls and cables atMonks Hill Beach, the converter station, and the landfall and cables at Brownwichwould not have any direct or indirect effect on any designated heritage assets.
3.1.17 There are six non-designated heritage assets within the development footprint forthe Monks Hill Beach landfalls and cables, none within the development footprintfor the converter station, and three non-designated heritage assets within thedevelopment footprint for the Brownwich landfall and cables.
3.1.18 The known heritage assets are of negligible heritage significance. The predictedmagnitude of effect is high. The significance of effects is therefore assessed asnegligible. In areas affected by converter station and cable installation atDaedalus and cable installation at Chilling there are finds which indicate that thepotential for as yet unknown heritage assets with archaeological interest ismoderate to high for certain types of asset. Measures are proposed to mitigatethe predicted negligible effect on known heritage assets within the developmentfootprints, and the potential for effects on as yet unknown heritage assets witharchaeological interest within the development areas.
3.1.19 The operational phase of the converter station at Daedalus would also have anadverse effect on adjacent non-designated heritage assets (D_NDHA 15, 16, 35and 67), a group of hangers dating to the 1930s expansion of Daedalus airfield.The setting of these assets includes the surrounding airfield, and this makes apositive contribution to the evidential and historic value of the assets. Theseassets are of moderate heritage significance. The magnitude of effect would below (adverse). The significance of effect would be low (adverse). The effects
IFA2 EIA SUMMARY
Page 30
would be long term, occurring throughout the operational phase of the project, butwould be reversible on decommissioning.
3.1.20 No significant historic environment effects are predicted. However in relation toeffects on heritage assets with archaeological interest, and to safeguard againsteffects on as yet undiscovered archaeological assets, a programme of mitigationis proposed, to comprise archaeological monitoring of topsoil stripping, andassociated recording, reporting and dissemination of results. This could besecured as a condition of planning consent, and subject to an approved WrittenScheme of Investigation.
Geology and Ground Conditions
3.1.21 The scope of this assessment of effects on geology and ground conditionscomprised of the following:
A site walkover of the Proposed Development sites;
A review of historical land use and potentially contaminative land uses;
A review of the geological setting and BGS boreholes in the vicinity of theProposed Development sites;
A review of mining history of the Proposed Development sites;
A review of environmental information relating to issues such asenvironmental permits, incidents and registers;
A review of the hydrogeological setting of the Proposed Development Sites;
A review of sensitive land uses within the vicinity of the ProposedDevelopment Sites;
An assessment of the potential effects and any mitigation measures thatmight be required.
3.1.22 The assessment identifies a number of potentially former and currentcontaminative land uses at the proposed Daedalus site but not at the proposedChilling site. Potential moderate adverse effects were identified to constructionworkers for the construction phase of the Proposed Development at the Deadalussite. However, these can be mitigated through the recommendations of groundinvestigation and the implementation of appropriate health and safety measures.
3.1.23 Potential moderate adverse effects were also identified to soils for theconstruction phase, through migration in open trenches and onsite movement.Again, these effects can be mitigated through ground investigation and if needed,impermeable barriers etc.
IFA2 EIA SUMMARY
Page 31
3.1.24 No significant effects were identified to groundwater resources, adjacent landusers or environmentally sensitive sites during the construction phase of theProposed Development.
3.1.25 No significant effects were identified to any of the receptors during the operationalphase of the Proposed Development.
Hydrology and Flood Risk
3.1.26 The Proposed Development is located close to the northern bank of the Solent inHampshire, close to the confluence with Southampton Water.
3.1.27 Water bodies that are in close proximity are the Solent; the Meon; and the RiverAlver. Also within the vicinity of the Proposed Development at Chilling areBrownwich Stream; Brownwich pond and two unnamed watercourses.
3.1.28 Direct interactions between the Proposed Development and waterbodies arelimited to the landfalls at Daedalus and Chilling (Solent) and the crossing of thetwo unnamed watercourses at Chilling.
3.1.29 The assessment has considered:
The impact on the Proposed Development from all sources of flooding;
The effects of the Proposed Development on local hydrology anddownstream flood risk due to an increase in surface water runoff or loss offloodplain; and
The effects of the Proposed Development on water quality in the local waterenvironment.
3.1.30 With regards to these effects, the construction, operational and decommissioningphases have been considered.
3.1.31 Potential effects on flooding could occur as a result of the crossing of the seadefences at Monks Beach (if open-cut techniques are used) and as a result of theincrease in impermeable area to accommodate the Converter Station on what iscurrently a greenfield site. Both of these risks would be reduced to no effectthrough the implementation of agreed construction methods (for the seadefences) and the design of the Converter Station, both in terms of building andsupporting infrastructure (drainage) design.
3.1.32 Potential effects on water quality could occur as a result of disturbance andsuspension of sediment in the Intertidal zone, particularly if open-cut methods areemployed. However, the assessment concludes that the IFA2 ProposedDevelopment is unlikely to have a non-temporary effect on the status of therelevant water bodies. The cable installation activities are not predicted to causedeterioration to the current status of the Solent coastal water body.
IFA2 EIA SUMMARY
Page 32
3.1.33 Potential effects on inland waters and surface water include silty water runoff,accidental spillages of polluting substances such as oil and cement. These wouldbe prevented by the implementation of standard construction practices forpollution prevention and control such as those outlined in this chapter. Furtherdetails of such measures will be provided in a Construction EnvironmentalManagement Plan (CEMP). As a result, no effects on water quality are predicted.
3.1.34 In terms of cumulative effects on flood risk and water quality, compliance withcurrent legislation, policy and best practice to control surface water runoff andpollution using industry standard methods and engagement with statutoryconsultees through the planning process would prevent in-combination effects ona local scale.
Traffic and Transport
3.1.35 The scope of the assessment of Traffic and Transport effects comprised thefollowing:
Consultation with FBC and HCC Highways;
A review of the local road network;
A review of existing traffic flows;
A review of data including annual average daily traffic flows on selectedroutes;
Personal injury accident data review;
A review of public transport provision;
A review of provision for Non- Motorised Users (NMUs) in the locality;
An assessment of the potential environmental effects against key networkoperational criteria; and
Identification of any mitigation measures that may be required.
3.1.36 The assessment concludes that the predicted construction traffic generated by theProposed Development will be low in comparison to the existing and forecastbackground traffic and will be temporary in duration.
3.1.37 The comparison of the Proposed Development construction traffic with the 2019traffic flows indicates that the overall traffic growth will be less than 10% and thatthe HGV traffic increases are less than 30% which results in a negligible level ofeffect.
3.1.38 A formal assessment of the capacity, delay and queuing at the new constructionvehicle access on Broom Way indicates that there will be no significant effectsresulting from the construction (or decommissioning) traffic on the operation or
IFA2 EIA SUMMARY
Page 33
safety of the north and southbound traffic flows on Broom Way. There will be littleregular traffic to the Proposed Development during the operational phase and assuch there will be no significant effects on traffic and transport.
Noise and Vibration
3.1.39 A combination of desk-based and site-based assessments were used to identifyand evaluate the potential noise and vibration effects on receptors arising fromthe construction and operation of the Proposed Development. The following wereused in the assessment:
Ordnance Survey mapping;
Topographical data;
Previous experience of similar developments elsewhere;
Plant noise data;
On-site noise monitoring data; and
Reference to relevant standards and guidance documents.
3.1.40 The assessment of construction and operational noise and vibration has beenundertaken in accordance with current best practice, including British Standardmethods for noise and vibration assessments as follows:
BS5228-1:2009+A1:2014 - Calculation for Noise from Open andConstruction Sites - Part 1: Noise
BS5228-2:2009+A1:2014 - Noise and Vibration Control on Construction andOpen Sites - Part 2: Vibration
BS7445: 2003 - Description and Measurement of Environmental Noise -Guide to Quantities and Procedures
BS 4142: 2014 – Methods for rating and assessing industrial and commercialsound
British Standard 8233:2014 Guidance on Sound Insulation and NoiseReduction for Buildings and World Health Organisation Guidelines forCommunity Noise
BS 6472-1: 2008 – Guide to evaluation of human exposure to vibration inbuildings – Part 1: Vibration sources other than blasting
IFA2 EIA SUMMARY
Page 34
3.1.41 The assessment indicates that noise due to underground cable construction atDaedalus and Chilling may lead to moderate adverse effects at the nearest noisesensitive receptors. The effects are expected to be minimised by utilising bestpractical means and appropriate noise mitigation. The assessment indicates thatconstruction of the Converter Station would lead to negligible construction noiseeffects. With regards to construction vibration, the assessment indicates thatnegligible effects would be expected for all construction activities. Constructiontraffic noise and vibration effects are expected to be negligible.
3.1.42 The assessment of the significance of effects due to operational noise hasconcluded that the effect of noise from the Converter Station would be of minoradverse significance. This is based on the noise limits which are expected to beapplied to the development, based on the results of this assessment, as part of aplanning condition, and verified during the detailed planning stage, if consented.There are no operational noise or vibration effects from underground cables.Operational vibration effects from the Converter Station have been considered.The assessment indicates that the operational vibration effects are expected to benegligible.
3.1.43 With regards to noise and vibration, the effects of decommissioning are expectedto be similar to those for construction. As such, decommissioning noise effectsare expected to be moderate and vibration effects are expected to be moderateadverse.
Air Quality
3.1.44 A desk-based assessment was applied to identify and evaluate the potential airquality effects on receptors, arising from the construction and operation of theProposed Development. The following information was used in the assessment:
Ordnance Survey mapping;
Previous experience of similar developments elsewhere;
Predicted traffic data relating to the development;
Local monitoring data; and
Reference to relevant legislation and guidance documents.
3.1.45 The assessment of potential dust/PM10 effects in relation to the ProposedDevelopment’s construction phase was undertaken qualitatively in accordancewith the Institute of Air Quality Management Guidance methodology. As theproposed Converter Station would utilise sulphur hexafluoride (SF6) in GasInsulated Switchgear (GIS), a qualitative assessment effects from any fugitiveemissions from SF6 gas was undertaken considering losses of SF6 through thesite equipment.
IFA2 EIA SUMMARY
Page 35
3.1.46 The assessment found that, providing effective mitigation measures are adoptedin relation to construction, and decommissioning related dust/PM10 effects and, airquality effects associated with the construction, operation and decommissioningof the proposed development would be not significant.
Electric and Magnetic Fields and Electro-magnetic Compatibility
3.1.47 The Government, acting on the advice of authoritative scientific bodies, has put inplace appropriate measures to protect the public from Electric and MagneticFields (EMFs). These measures comprise compliance with the relevant exposurelimits, and one additional precautionary measure, optimum phasing, applying toonly to high-voltage overhead power lines. These measures are set out in aWritten Ministerial Statement, National Policy statement EN-5, and various Codesof Practice. The assets associated with the proposed development would be fullycompliant with the Government policy. Specifically, all the fields produced wouldbe below the relevant exposure limits. Therefore there would be no significantEMF effects resulting from this proposed development.
3.1.48 Based on the Electro-magnetic Compatibility (EMC) performance of the NGETsystem as a whole having been certificated as compliant with Directive89/336/EEC (Ref. 1.Error! Bookmark not defined.) by a Competent Bodyfollowing appropriate onsite testing, and controls on the EMC performance of theconverter station, the Proposed Development is assessed as producing nosignificant EMC effects during construction, operation and decommissioning,except for interference within 15 m of the cable with operations such as compasscalibration that require an unperturbed geomagnetic field, which is assessed as aminor adverse effect during the operational phase.
3.1.49 Although no significant EMC effects are expected, National Grid is working withspecific operators on the Daedalus site with equipment or operations that may beunusually sensitive to EMC issues, to establish any likely problems and, ifnecessary, solutions.
Socio-Economics
3.1.50 Socio-economic assessments have been undertaken to assess the likelysignificant changes to the socio-economic baseline, resulting from the ProposedDevelopment. The assessment undertaken used qualitative and quantitativetechniques and was based on the Good Practice Guide on EnvironmentalAssessment, the government’s Green Book for Appraisal and Evaluation as wellas professional judgement and experience.
3.1.51 The assessment concludes that, provided various appropriate mitigationmeasures are used during the construction, operation and decommissioningphase, none of the identified effects on employment, community infrastructure,deprivation, recreation and leisure, and local economy would be significant. Inparticular, specific mitigation would be required to address an identified significant
IFA2 EIA SUMMARY
Page 36
effect on the recreation and leisure resource, relating to direct effect on the localcar park and cycle route severance, and indirect effect on beach hut users.
3.1.52 Cumulatively, there is potential for other developments (e.g. the development ofthe Airfield for employment use, and nearby residential developments to increasethe risk and severity of disturbance (e.g. noise and air quality) on the nearbyrecreational resource (e.g. the beach). This would be managed throughstakeholder consultation and best practice construction environmentalmanagement. All developments will stimulate some degree of employment, andas such there will be positive cumulative effects associated with the investmentand the resulting direct, indirect and induced employment generation (both duringconstruction and operation).
Cumulative Effects
3.1.53 A detailed review of existing and planned projects which may result in cumulativeeffects was undertaken and it was concluded that there would be no significantadverse cumulative effects.
3.2 UK Marine and Intertidal EIA
Introduction
3.2.1 This section provides a summary of the findings of the UK marine and intertidalEIA for each environmental topic assessed and provides details of the surveywork undertaken to inform the EIA process. There is also a discussion in relationto cumulative and transboundary effects.
Surveys Undertaken
3.2.2 A wide range of surveys were undertaken to inform the UK EIA. An overview ofthe survey works that have taken place is outlined below. The surveys wereundertaken using standard methods informed by relevant guidance andstakeholder consultation.
Geophysical surveys of the entire cable route corridors to provide details ofseabed bathymetry, morphology and presence of wrecks and obstructions onthe seabed.
Geotechnical survey which involved collecting geological core samples alongthe cable routes to provide details of geology of the seabed. Several ofthese core samples were also tested for contaminants to ensure cable burialwould not disturb areas of contamination.
IFA2 EIA SUMMARY
Page 37
Seabed habitat surveys.
Intertidal walk over surveys to determine local ecology and habitats.
Shore based wintering and breeding bird surveys.
Approach to Impact Assessment and Key Findings
Physical Environment
3.2.3 For the purposes of this impact assessment physical environment was defined asincluding the shallow geology, bathymetry, seabed sediments, sediment transport,sediment contaminants, tides and currents, and water quality in and around theProposed Development2. The baseline was established using geophysical,geotechnical (including contaminant sampling) and benthic survey data primarily(see Table 3.2 for further details) supported by desk-based assessment of therelevant sources, such as previous regional studies and the project’s own initialfeasibility assessments.
3.2.4 All potential effects in relation to the installation phase were predicted to be of anegligible to minor nature due to the temporary and localised nature of the effects.During the operational phase, all predicted effects are considered to be ofnegligible significance as, once the cable is buried, there is unlikely to be furtherdisturbance with the exception of unscheduled maintenance.
3.2.5 Residual effects in relation to the physical environment are all of negligible tominor significance.
Benthic Ecology
3.2.6 The baseline was established based upon the findings of the IFA2 ProposedDevelopment’s benthic habitat, geophysical and intertidal surveys in addition to adesk based assessment using a number of broad scale regional studies and GISresources specific to the benthic habitats within the study area.
3.2.7 The study identified a number of designated sites with important benthic habitats,such as Special Areas of Conservation (SACs) and Marine Conservation Zones(MCZs). No SACs are crossed by the cable route however the potential forindirect effects of nearby SACs was assessed. Two MCZs are crossed by thecable route, and another is in close proximity and therefore specific focus in aseparate assessment has been given to potential effects upon the benthiccharacteristics of these sites. There is an area of protected seagrass at the
2 References to “Proposed Development” in section 3.2 are to the UK intertidal and marine elements of the IFA2 project.
IFA2 EIA SUMMARY
Page 38
Brownwich landfall in the intertidal zone. No areas of biogenic reef wereobserved during the survey.
3.2.8 The use of HDD and careful cable routing have resulted in no significant effectsbeing predicted in relation to the key benthic faunal groups identified along thecable route. Furthermore, no significant effects are anticipated in relation to theprotected seagrass or other habitats of conservation importance.
3.2.9 In respect of potential effects on MCZs, an MCZ assessment was undertakenusing an approach based upon MMO guidelines to determine the potential effectswhich could occur. This considered the potential of direct disturbance to benthichabitats of conservation importance in addition to potential effects from depositionof cable protection material, deposition of sediment and potential increases tosuspended sediment concentrations. The assessment concluded that only verysmall areas of habitat within the MCZs would be affected and the majority of thefeatures are either not sensitive or have a high rate of recoverability to potentialeffects. Therefore it was concluded that no significant adverse effects to theoverall conservation objectives of the MCZs is likely.
Fish and Shellfish Ecology
3.2.10 The assessment was informed by various sources including the large amount ofdata on diversity, abundance and spawning areas of fish and shellfish alreadyavailable for this highly surveyed area, survey data provided by the SouthernInshore Fisheries and Conservation Authority (SIFCA) and survey data from tworecent offshore developments in the vicinity. Guidance from, and consultationwith, documents from Cefas, the MMO, Natural England, the Environment Agencyand SIFCA were also used to inform the assessment.
3.2.11 Potential effects arising from installation of the cable, either in relation to directdisturbance, sediment deposition, or temporary increases to suspendedsediments were identified in relation to disturbance of shellfish (such as oysters)and fish species that spawn on the seabed, such as herring. However, only thepotential effects on degraded former oyster beds were classed as having potentialfor moderate significance despite the low density of individual oysters present.This was due to the fact that although the oyster beds are currently degraded withvery few individuals present, cable installation may hinder future recovery of theoyster bed. All other potential effects were classed as negligible to minor.
3.2.12 In terms of the potential moderate effect upon the oyster bed crossed by theHVAC cable route, further engagement with the Southern IFCA will be undertakenin order to define mitigation measures to address this issue. No other mitigationswere considered necessary in relation to fish and shellfish given the low level ofpredicted impact.
Ornithology
IFA2 EIA SUMMARY
Page 39
3.2.13 The ornithological impact assessment was undertaken using desk-based sources,data from field surveys of intertidal birds at the two landfalls, aimed at winteringand breeding birds and through consultation with statutory bodies. Surveys tookparticular note of species named in SSSI/SPA designations. The desk-basedassessment focussed on two high level regional sources of data to support thesurvey findings. The baseline established that the broad range of habitats on thesouth coast supports nationally and internationally important bird species. Due toits location, this area of coastline is regularly transited by migratory speciestravelling to and from breeding and feeding grounds. There are a number ofSpecial Protection Areas (SPAs) in the vicinity of the cable route, and one iscrossed by the two cable landfalls.
3.2.14 Direct disturbance, loss of habitat and/or changes to prey supply in addition toaccidental releases or spills were considered in terms of potential effects on birdspecies. Mitigation measures were proposed during the construction phase inorder to minimise any potential effects including the sensitive timing ofconstruction activities at the landfalls. Navigational safety measures will alsoreduce the likelihood of accidental spills. No mitigation measures wereconsidered necessary during the operational phase, as there are no potentialeffects predicted from the installed offshore cable except in the event thatunscheduled maintenance is required. Following the inclusion of the mitigationmeasures proposed, the potential effects on bird species are predicted to beminor, with the exception of accidental spills where the impact is could bemoderate, should an accidental spill occur. However, it is considered that there isan extremely low probability of this occurring during construction, operation ordecommissioning if environmental management plans and pollution contingencyplans are in place.
Marine Mammals
3.2.15 This impact assessment included a study of the potential effects upon whales,porpoises, dolphins and seals. The baseline was determined by consideration ofdesk based sources including the JNCC Marine Mammals Atlas and studiesundertaken to inform the aggregates industry with some anecdotal evidence interms of marine mammal distribution from consultees. The assessment also drewupon marine mammal survey data from two recent offshore wind developments.
3.2.16 Cetaceans (whales, dolphins and porpoises) have a relatively low abundance inthe eastern English Channel with only occasional sightings of a relatively smallnumber of species. There are two species of seal in UK waters, the harbour sealand the grey seal. There are two haul out sites for harbour seals at LangstoneHarbour and Chichester Harbour despite a relatively low presence of this speciesin the study area. Grey seal are scarcer in the study area with no haul out sitesand no presence within the Solent.
3.2.17 Effects were considered in relation to noise and vibration, entrainment/collisionwith vessels, the effects of suspended sediments and the effects of EMF
IFA2 EIA SUMMARY
Page 40
emissions from the installed cable upon marine mammals. No significant residualeffects upon marine mammal species were predicted
Nature Conservation Designations
3.2.18 As discussed in above the Proposed Development is in the vicinity of severalNatura 2000 and Ramsar sites and as such information has been provided withthe EIA to inform Habitats Regulation Assessment (HRA) which will beundertaken by the Competent Authorities (in the case the MMO and FBC). Thecable route also crosses two Marine Conservation Zones (and is in closeproximity to a third) as discussed above. The cable route crosses a protectedseagrass bed at Brownwich Chilling, but effects will be mitigated by using HDDinstallation techniques under this area.
3.2.19 Assessment of effects concluded that there are no significant adverse effectspredicted to arise from the Proposed Development on either Natura 2000 sites orMCZs.
Shipping and Navigation
3.2.20 The Channel and in particular the Solent are important for major shipping routesfor passenger, freight and military vessels. The area is also an importantrecreational area for water sports, particularly yachting. The assessment inrelation to shipping and navigation was predominantly undertaken using desk-based and publicly available data including admiralty charts, AutomaticIdentification System (“AIS”) and other surveillance data, and data from publicsector organisations (e.g. RNLI marine incident data). This was supported byconsultation with appropriate stakeholders, most notably in respect of commercialfisheries where a series of open forum stakeholder meetings were held with localfishermen. In line with standard practice a navigational risk assessment processwas undertaken in line with Maritime and Coastguard Agency guidance to identifypotential effects. The assessment considered effects on commercial, passenger,recreational, marine aggregate, fishing and military vessels. The data used andassessment method were agreed with marine stakeholders including the Maritimeand Coastguard Agency, Trinity House Light Service and local ports andharbours.
3.2.21 Potential effects classed as “tolerable with further mitigation required” (a widelyused term in navigational safety risk assessments) were noted for commercialvessels, passenger vessels and military vessels during the construction anddecommissioning phases mostly resulting from increased traffic. These potentialeffects comprised collision risk, disruption to port schedules for arrivals anddepartures, and disruption to marine military exercises. In respect of theoperational phase, potential effects of the same classification were also identifiedrelating to commercial and fishing vessels. This was due to the potential foranchors or fishing gear snagging on the installed cable, electric and magnetic field(“EMF”) interference, reduced water depths in areas where cable protection is
IFA2 EIA SUMMARY
Page 41
used or where cable crossings are necessary, collision risk with maintenancevessels, and anchoring over the cable route in an emergency.
3.2.22 Industry standard mitigations are proposed in order to offset the potential effectson shipping and navigation. These include the promulgation of information viaNotice to Mariners and other established means, emergency planning, the use ofguard vessels and deployment of temporary aids to navigation, the use of safetyzones around installation vessels, charting of the installed cable, communicationplans, and monitoring of the installed cable to ensure that protection methodsremain effective. Communication plans and ongoing liaison with appropriatestakeholders has also been proposed to minimise the potential for effects onshipping and navigation. Following implementation of the above mitigationmeasures, the residual effects were then classed as acceptable in terms of risk tomarine vessel and craft with no further mitigation required.
Commercial Fisheries
3.2.23 The baseline in relation to commercial fisheries has been compiled using a broadrange of desk-based data sources such as landings data, surveillance sightings,satellite tracking data obtained from UK, French and Belgian authorities.Consultation with groups representing several types of fisheries in addition toopen forum stakeholder meetings with local fishermen have been undertaken toinform the impact assessment during 2015-16. The baseline determined that thestudy area is utilised by commercial fisheries originating from the UK, France,Belgium and the Netherlands.
3.2.24 Whilst there is no specific guidance in relation to the impact assessment ofcommercial fisheries, the assessment took note of broader guidance published byCefas, the Sea Fish Industry Authority and UK Fisheries Economic Network,FLOW guidelines, and the International Cable Protection Committee. A list ofreceptors based upon the level and type of fishing activity from each of theoriginating countries was drafted to form the basis for the assessment of effects.The only potentially significant effects are likely to occur during the constructionphase, and will thereby be temporary in nature. These include effects on staticgear and drift netting, otter and beam trawling in vessels under 15 m in length,and inshore scallop and clam dredging. No significant effects on other types ofgear were identified.
3.2.25 Mitigation measures considered appropriate in order to address the potentialsignificant effects were the establishment of a Working Group involving keyfisheries stakeholders to provide a forum for ongoing consultation duringconstruction, in addition to the development of a Construction EnvironmentalManagement Plan and Fisheries Liaison Protocol which would, amongst otherthings, establish clear communication channels between the Applicant andfishermen to aid in the management of fisheries issues during the constructionphase. Both of these are considered industry standard mitigation measures and,subsequent to their use, it is predicted that there are no significant residual effectsin relation to commercial fisheries.
IFA2 EIA SUMMARY
Page 42
Archaeology and Cultural Heritage
3.2.26 A near shore and offshore archaeological assessment informed by numerousdocumentary and cartographic sources was undertaken to determine the baselinein relation to archaeology and cultural heritage. Data from the geophysical andgeotechnical surveys (refer to survey table) was also used to ground truth thedesk based analysis. The baseline was established in relation to the followingcultural heritage assets:
Shipwrecks, crashed aircraft and wreck material;
Submerged prehistoric heritage and artefacts; and
Areas of archaeological potential.
3.2.27 The assessment was completed in accordance with current guidance fromEnglish Heritage, the Joint Nautical Archaeology Policy Committee (JNAPC), theChartered Institute for Archaeologists (CIfA) and COWRIE. The data used andassessment method have also been discussed with Historic England.
3.2.28 The cable routes have been designed to avoid known wreck locations.
3.2.29 The archaeological impact assessment considered direct effects uponarchaeological features such as direct disturbance from installation of the cable,vessel activity and anchorage, in addition to indirect effects such as scour orsediment deposition. All phases of the Proposed Development were assessedand no significant environmental effects were predicted.
3.2.30 Potential effects upon palaeo-archaeological features (such as submerged riverbeds known as paleochannels) identified during survey were also considered.Although these features are judged to have a high sensitivity to disturbance, thesmall linear footprint of the IFA2 cable on these extensive landscapes will beminimal. Therefore no significant effects have been predicted in relation topalaeochannels.
3.2.31 Industry standard mitigation measures were proposed in line with good workingpractice. These include the definition and recognition of Archaeological ExclusionZones (AEZs) to avoid effects on hitherto unknown wrecks, the preparation of anArchaeological Written Scheme of Investigation, and the establishment of areporting protocol in respect of any finds made during offshore activities.Additionally, the Proposed Development will ensure adherence to relevantlegislation in respect of the treatment of wreck material, treasure and remains.
Other Marine Users
3.2.32 The assessment was undertaken using desktop analysis supported byconsultation with relevant stakeholders. Other marine uses considered within theimpact assessment were aggregate extraction; marine disposal; navigationaldredging; offshore energy (including oil and gas, offshore wind and tidal devices,
IFA2 EIA SUMMARY
Page 43
military use (other than those related to shipping and navigation) and unexplodedordnance (UXO); offshore and intertidal structures such as cables, pipelines,outfalls and groynes; and recreational uses such as coastal walking, bathing,recreational angling and charter boats, scuba diving, surfing and kite surfing, andjet and water skiing.
3.2.33 The assessment identified that potential effects during construction may beexperienced due to temporary exclusion zones and the potential for encounteringUXO which may require disposal. There is also potential for temporary increasesin suspended sediment concentrations to have an effect on some recreationalactivities. It also determined that all effects would be temporary and localised innature.
3.2.34 A number of mitigation measures have been proposed which are routinelyimplemented for offshore projects with potential effects on other marine users.These include ongoing liaison with appropriate stakeholders such asrepresentatives of potentially affected industries to proactively manage anyscheduling conflicts between the Proposed Development and other marineactivities. The Proposed Development will also promulgate relevant informationto all relevant other marine use receptors via a Notice to Mariners, such asconstruction timings.
3.2.35 Potential risk from UXO will be minimised using established practice, such asundertaking a further UXO survey prior to construction to identify any magneticanomalies which may potentially represent UXO and enable micro routeingaround these features. A UXO protocol will also be established which will befollowed in the event that UXO is encountered during construction.
3.2.36 Following implementation of these mitigation measures, there are no predictedsignificant residual effects in relation to other marine users.
Interrelationships and Cumulative Effects
3.2.37 The key environmental effects resulting from the cable installation and operationthat may result in cumulative effects with other developments were identified tobe:
Loss or restricted access to fishing grounds impacting commercial fisheries ;
Collision risk / disruption impacts to shipping and navigation;
Turbidity impacts on water quality, benthic ecology, and fish and shellfishand associated smothering impacts;
Direct physical impacts on benthic ecology and fish and shellfish fromseabed disturbance;
Noise impacts on marine mammals and fish and shellfish; and
Scour impacts on marine heritage assets.
IFA2 EIA SUMMARY
Page 44
3.2.38 A detailed review of existing and planned projects which may result in cumulativeeffects was undertaken and due to the small footprint of the ProposedDevelopment and short duration of the construction works it was concluded thatthere would no significant cumulative effects in the long term.
3.3 French Marine and Intertidal EIA
Introduction
3.3.1 This section provides a summary of the findings of the French marine andintertidal EIA for each environmental topic assessed and provides details of thesurvey work undertaken to inform the EIA process.
Surveys Undertaken
3.3.2 A wide range of surveys were undertaken to inform the French EIA. An overviewof the survey works that have taken place is outlined below. The surveys wereundertaken using standard methods informed by relevant guidance andstakeholder consultation.
Geophysical surveys of the entire cable route corridors to provide details ofseabed bathymetry, morphology and presence of wrecks and obstructions onthe seabed.
Geotechnical survey which involved collecting geological core samples alongthe cable routes to provide details of geology of the seabed. Several ofthese core samples were also tested for contaminants to ensure cable burialwould not disturb areas of contamination.
Seabed habitat surveys.
Intertidal walk over surveys to determine local ecology and habitats.
Shore based breeding bird surveys.
Approach to Impact Assessment and Key Findings
Geomorphology and Bathymetry/Topography
3.3.3 The geomorphology and bathymetry of the cable route and the cable landfall wasdetermined using desk-based data from previous studies carried out in the area,ground-truthed by the geophysical and geotechnical surveys completed in 2013and 2014.
IFA2 EIA SUMMARY
Page 45
3.3.4 In terms of potential effects to the geomorphology of the cable route and landfall,the key area of impact would be related to be pre-sweeping activities at thesandbanks, such as the Seine Sandbank. Pre-sweeping is used to dredge thecrests of sandbanks or sand waves on the seabed to enable the use of cableburial machines and help ensure that the cable is buried below the mobilesediments. Effects of this activity are considered to be temporary given the goodsediment mobility at the site and localised and therefore are classed as minor. Ifpre-sweeping is used it is likely that less intervention (to undertake remedial burialor rock placement to maintain cable protection) will be required during theoperational phase. Effects to the topography of the beach at the cable landfallduring site preparation and installation works are also considered minor due to thetemporary nature of installation.
3.3.5 Mitigation measures considered appropriate in terms of the potential minor impactto geomorphological features include ensuring that the cable routing and burial isdesigned to minimise the use of pre-sweeping and rock protection to minimisedisturbance to the seabed. At the cable landfall, reinstatement of the site to itsoriginal conditions will be undertaken following installation of the cable. Followingthe application of these mitigation measures, there are no residual effects togeomorphology and bathymetry/topography.
Geology
3.3.6 The geology of the cable route and the cable landfall was determined using desk-based data from previous studies carried out in the area, ground-truthed by thegeophysical and geotechnical surveys completed in 2013 and 2014. The keygeological features in relation to the French cable route and landfall identifiedwere the Seine sandbank at the mouth of the River Seine, and an area of sandcover across a large proportion of the Bay of Seine. Subsoils were alsocharacterised and include chalk, clay marl and marl-limestone.
3.3.7 The impact assessment predicted either negligible or no impact upon geologyduring site preparation, construction, operation or decommissioning phases. Dueto the negligible impact to geology, no mitigation measures were considerednecessary.
Sediments
3.3.8 The geology of the cable route and the cable landfall was determined using desk-based data from previous studies carried out in the area, ground-truthed by thegeophysical and geotechnical surveys completed in 2013 and 2014.
3.3.9 For the majority of potential effects considered during all phases of the ProposedDevelopment, these were classed as either negligible or no impact was predicted.This was largely due to the relatively small area affected and the temporarynature of effects during the construction phase. One potential impact was
IFA2 EIA SUMMARY
Page 46
identified in terms of the potential effects of installation within the SeineSandbank. However, given the fact that the sediments are likely to replenish inthe medium terms and the effect is therefore reversible and localised, this wasassigned a minor significance.
3.3.10 Despite the relatively low level of potential impact in relation to sediments, anumber of industry standard mitigations are proposed in line with best practice,such as the sensitive routing of the cable in terms of seabed characteristics, theavoidance of the use of external cable protection by opting to bury the cablerather than lay it on the surface, and minimising the use of pre-sweeping to allowfor burial of the cable. Following the application of these mitigation measures,there is no predicted residual impact to seabed sediments.
Sediment Dynamics
3.3.11 The assessment in relation to sediment dynamics was undertaken using desk-based data from previous studies carried out in the area, ground-truthed by thegeophysical and geotechnical surveys completed in 2013 and 2014. The coastalprocesses of the Eastern Channel, the Bay of Seine and the Orne Estuary werecharacterised and the sediment dynamics along the cable route and at the cablelandfall were determined. The stability of the coastline in the vicinity of theProposed Development was also considered.
3.3.12 The assessment determined that sedimentary dynamics are affected by seaconditions, such as tide and swell and that the Seine sandbank and the beach atthe cable landfall were especially sensitive to changes to these conditions. Interms of potential impact, a minor impact is predicted in relation to pre-sweepingactivity at the Seine Sandbank. The impact is considered minor due to the factthat no sedimentary material is removed following excavation but is reintroducedto be replenished by local hydrodynamic conditions at the sandbanks.
3.3.13 The introduction of cable protection in areas where cable crossings are requiredduring installation of the cable are also predicted to have a potential impact onsediment dynamics in that it forms a barrier to the transit of seabed sediments inthese areas. This impact is predicted during both the construction andoperational phases of the proposed development; however, given that this affectsa relatively small area, the impact is classed as minor.
3.3.14 No other potential effects are predicted along the cable route beyond negligiblesignificance and no potential effects are predicted at the cable landfall.
3.3.15 Mitigation measures considered appropriate in terms of the potential minor impactof the project include the avoidance as much as possible of high mobility areas interms of cable routing, the preference for cable burial rather than surface layrequiring the use of cable external protection (except in areas where cablecrossings are necessary), establishing a required burial depth, and thepreferential use of ploughing as opposed to jetting burial techniques. Followingthe application of these mitigation measures, there are no residual effects tosedimentary dynamics.
IFA2 EIA SUMMARY
Page 47
Natural Hazards
3.3.16 A study was conducted to determine the hazards in relation to the installation ofan underground cable in terms of the following:
To assess the potential for increase of natural hazards (in particular flowing)on the local population; and
To assess the constraints that may be required during construction andoperation to avoid increasing the risk of natural hazards.
3.3.17 Amongst other types of hazard, flooding, seismic activity and the risk of groundmovement were the main focus of consideration as part of this assessment basedupon data from the Dossier Départemental des Risques Majeurs du Calvados(“DDRM”).
3.3.18 Around the location of the Proposed Development, the major flood risk is fromlowland flooding, but also from flooding following storm events which cansometimes generate flash floods, however the installation at the cable landfall isnot considered to increase the risk of flooding. The cable landfall is also locatedin an area of low seismic risk. There is considered to be a negligible impact interms of natural hazards, therefore no mitigation measures are considerednecessary.
Benthos
3.3.19 The benthic environment was characterised using data from many sources, suchas broad scale species data, qualifying ecological features of sites designated forconservation in addition to previous ecological assessment and reports. Abenthic survey was also undertaken in 2013 which ground-truthed the desk-baseddata.
3.3.20 During the impact assessment, a number of potential effects were identifiedduring site preparation and construction. These included the directdisturbance/damage to benthic habitats and species from the use of pre-sweepingmachines and cable burial techniques. Effects to general benthic communitieswere considered in addition to the effects upon a species of Brittlestar, Ophiotrixfragilis, which is a qualifying feature of the Baie de Seine ZNIEFF (Zone NaturelleD'intérêt Écologique, Faunistique et Floristique). In all cases, the footprint ofdisturbance is relatively small and it is considered that there will be a high rate ofrecolonisation. It was also considered that in some instances the potential use ofcable protection, e.g. at cable crossings, may aid recolonisation of benthiccommunities. In terms of Ophiotrix fragilis, the four core areas of high density ofthis species are avoided by the cable route within the ZNIEFF. In addition todirect disturbance the effects of increased turbidity arising from suspension ofsediments was also considered. Generally, the benthic species found along thecable route that may be affected by this impact are tolerant to changes in turbidity.Therefore, for all potential effects upon benthic species and habitats were classed
IFA2 EIA SUMMARY
Page 48
as minor. Moreover, the study found that all burial techniques considered yieldeda similar level of impact, although jetting is considered to cause a higher level ofturbidity.
3.3.21 Mitigation measures were proposed such as the sensitive timing of constructionactivities in relation to breeding periods, the preference of the use of ploughingtechniques over jetting and routeing to minimise the requirement for pre-sweepingactivities. The potential risk from accidental spills or releases causing pollution isproposed to be minimised through safety and management procedures on boardinstallation and supporting vessels.
Plankton
3.3.22 Planktonic communities along the cable route were determined using desk-baseddata, such as broad scale indices and species lists and previous ecologicalassessment and reports.
3.3.23 In terms of phytoplankton two effects may occur from construction; i.e. leaching ofnutrients from exposed sediment can boost its development, whilst increasedturbidity may have the opposite effect and inhibit its growth. In respect ofzooplankton (animal-based plankton such as eggs and larvae), a number ofeffects are considered possible. These include direct destruction of fish eggs ordestruction of these through movement into other deeper areas of the watercolumn where the physical conditions are not suitable or there is increasedpredation, and the smothering of zooplankton on seabed sediments by re-deposition of suspended sediments. Due to the low level of suspended sedimentproduced and its rapid dispersion, potential effects to phytoplankton andzooplankton are considered “very minor” and “minor” respectively. In terms ofeffects upon zooplankton (in the form of surface laid eggs and larvae such assole), the footprint of direct disturbance is likely to be small and therefore thispotential impact is also considered to be minor.
3.3.24 Mitigation measures proposed include the preference of ploughing techniquesover cable burial using jetting equipment technically and economically compatibleand the sensitive routeing in relation to sandbanks and sandwaves in order tominimise the level of pre-sweeping activity required.
Fish, Cephalopods and Crustaceans
3.3.25 The impact assessment on fish, cephalopods (squid) and crustaceans wasundertaken using data from a number of desk-based sources, such as broadscale species lists, qualifying ecological features of sites designated forconservation, previous ecological assessment and reports, and fisheries data.
3.3.26 Effects considered in relation to fish, cephalopods and crustacean species includenoise, increased turbidity, damage and injury to individuals from installationequipment, trophic disturbance to feeding areas and disturbance from increased
IFA2 EIA SUMMARY
Page 49
vessel traffic. Potential effects largely depend on the life cycle of an individualwith those species at an earlier life stage potentially being less mobile to enableavoidance of an effect than older individuals.
3.3.27 The majority of effects were indentified during pre-sweeping and installationactivities. Moderate effects were identified in terms of the potential effects uponthe spawning and nursery grounds for plaice, sole and herring for directdisturbance, especially during specific times of the year where spawning of thesespecies occurs. There are also potential effects in terms of direct disturbance onthe Seine Sandbank from pre-sweeping activities for species of commercialimportance using the area as a nursery ground. The Proposed Development isalso close to a cuttlefish spawning area which is in use over the spring period. Interms of the effects of re-deposition of suspended sediment, these potentialeffects are considered to be minor. In relation to potential noise effects, thesewere predicted to be of a moderate significance for flounder, sole and shrimp inthe coastal regions during construction. Other potential noise effects in relation toother species were predicted to be of a minor level. No significant effects wereidentified during the operational phase.
3.3.28 Mitigation measures proposed include the sensitive timing of offshore activities inrelation to the commercial fish such as scallop fishing season spawning months ofcertain species at specific locations along the cable route, the preference ofploughing techniques instead of jetting machines for cable burial if technically andeconomically compatible, the minimisation of the requirement for pre-sweepingthrough the sensitive routing of the cable route in relation to sandbanks, and theuse of a soft-start procedure during any seismic surveys. The potential risk fromaccidental spills or releases causing pollution is proposed to be minimisedthrough safety and management procedures on board installation and supportingvessels.
Shellfish
3.3.29 The impact assessment in relation to shellfish was undertaken using desk-baseddata supported by the results of the benthic survey carried out 2013. Desk-basedsources include broad scale species lists, in addition to previous ecologicalassessment and reports.
3.3.30 Only minor effects were identified upon shellfish species such as scallop and clamduring pre-sweeping and installation of the cable due to direct disturbance. Aminor rating was applied as the affected species occur in low densities and due tothe rate of recolonisation which is expected. The footprint of effect is alsorelatively small. A potential impact was also identified in relation to heating of theseabed from the installed cable during the operational phase. This was alsoconsidered to be of minor significance due to the small area affected and the lowlevel of effect.
3.3.31 A number of mitigation measures have been proposed such as the sensitivetiming of offshore activities, the use of ploughing rather than jetting where
IFA2 EIA SUMMARY
Page 50
possible in respect of cable burial techniques. The potential risk from accidentalspills or releases causing pollution is proposed to be minimised through safetyand management procedures on board installation and supporting vessels.
Ornithology
3.3.32 A coastal bird survey was undertaken to inform the ornithological impactassessment in addition to analysis of desk-based data, such as broad scaleindices and species lists and previous ecological assessment and reports.
3.3.33 All potential effects in relation to birds are predicted to be of negligible to minorsignificance. Those classed as minor consist of effects to the food chain (eitheroffshore in relation to fish or at the cable landfall which is used as a foragingground by certain species), direct noise disturbance and disturbance to habitats.All of these effects are temporary and localised, hence they are only of minorsignificance. The use of HDD precludes a greater potential impact to groundnesting birds in the dune habitat.
3.3.34 Mitigation measures proposed include the phasing of site preparation,construction and landfall activities to avoid nesting periods, the use of ploughingrather than jetting where possible in respect of cable burial techniques, and thereinstatement of the cable landfall site to its original state following cableinstallation.
Marine Mammals
3.3.35 An aerial marine mammal survey was undertaken to inform impact assessmentfor a nearby offshore wind farm project was used to inform this assessment inaddition to analysis of desk-based data, such as broad scale species lists andprevious ecological assessment and reports.
3.3.36 Potential effects include noise effects (either from pre-construction survey workusing acoustic techniques to determine geophysical conditions, or frominstallation activities), or effects upon the food chain (either from directdisturbance or from smothering of prey species). All of these effects wereconsidered to be negligible to minor due to the mobility of the species and thetemporary and localised nature of the effects. Potential disturbance to sealsfrequenting the coastal area was considered. This was considered to be of minorsignificance as haul out sites are of sufficient distance from the cable landfall tominimise effects on these populations. Collision risk was also considered but thispotential impact was predicted to be negligible.
3.3.37 Mitigation measures proposed consist of the use of ploughing rather than jettingwhere possible in respect of cable burial techniques, the use of a marine mammalobserver and the implementation of a soft-start procedure. The potential risk fromaccidental spills or releases causing pollution is proposed to be minimised
IFA2 EIA SUMMARY
Page 51
through safety and management procedures on board installation and supportingvessels.
Bats
3.3.38 The impact assessment in relation to bats was undertaken using desk-based datasuch as broad scale indices, in addition to previous ecological assessment andreports.
3.3.39 The impact assessment examined the potential effects of the ProposedDevelopment on bats dwelling in the forests of the coastal region and those usingthe Baie de Seine as a corridor for migration along the coastal area. Fourmigratory species are believed to be present in the Baie de Seine and, followingrecent research, there is potential for bat species to hunt for insects andcrustaceans in the coastal area in the right conditions. However, only potentialeffects of a negligible significance are predicted in relation to bat species,therefore no mitigation measures were proposed.
Human Environment
3.3.40 The human environment is concerned with all human activities occurring in themarine and/or littoral areas. The assessment is predominantly carried out usingdesk-based study mainly using information issued by private or public sectororganisations in relation to specific activities. The assessment of the humanenvironment included commercial fisheries, shipping and navigation, recreationalactivities and other marine users (e.g. military training areas, maintenance andaggregate dredging activities, cables and pipelines and energy projects).
3.3.41 In addition two further desktop studies were commissioned by specialistconsultancies in relation to commercial fisheries and covered both French andEnglish waters with specific focus on the Baie de Seine area in France. Thesestudies also involved meetings with fisheries representatives. During cablerouting, constraints identified in relation to human activities offshore and the areasused for these activities were avoided to minimise impact. Following the EIA“Moderate” effects were identified concerning shipping and navigation, fishingactivities, existing network of cables and aggregate extraction. During theconstruction phase, there will be temporary displacement in relation to establishedshipping routes and fishing activities in addition to temporary and localised effectson water quality from increased turbidity and direct and indirect disturbance tocommercial fish populations. The most significant effects arise from pre-sweeping, route clearance, cable laying and post-laying, and potential formaintenance to the installed cable. The buried cable is not predicted to have animpact upon human activities with the exception of cable protection which willpresent a permanent impact on fishing. Recreational activities taking place on thewater will also be temporarily impacted due to displacement, however this will
IFA2 EIA SUMMARY
Page 52
affect a localised area and therefore is not considered to compromise recreationalactivities on a broad scale. At the cable landfall, construction is predicted topresent a potential impact to those recreational activities occurring at thecoastline, especially during the summer months. The decommissioning phase isanticipated to similar but reduced effects to the construction phase.
3.3.42 Embedded mitigations were already in place prior to undertaking the EIA, such assensitive cable routing to avoid major constraints, for example popular mooringzones. In order to prevent or minimise potential effects on the humanenvironment, further mitigations measures have been proposed. These areindustry standard measures including consultation with the local authorities andthe public to ensure safety to human activities during construction, the cleardemarcation of the construction area and restricted access to the eastern mooringzone at “Caen Ouistreham” harbour, the maximisation of cable burial (rather thansurface laying with cable protection) in the nearshore area, the preference to usecable burial techniques which limit the production of suspended sediments, theapplication of a 1 nautical mile buffer zone in respect of aggregate extraction sitesand, where cable protection is necessary, using concrete mattresses rather thanrock dumping. The construction contractor is also required to ensure that thetiming of works are sensitive to human environment receptors and to ecologicalreceptors on which recreational activities depend.
Shipping and Navigation
3.3.43 The assessment was predominantly carried out using desk-based study mainlyusing information issued by private or public sector organisations in relation tospecific activities and cartographic sources. It covered shipping routes, areas formaritime and shipping use (e.g. access routes to ports and anchorage areas),port activities and maintenance dredging.
3.3.44 During cable routing, constraints identified in relation to human activities offshoreand the areas used for these activities were avoided to minimise impact.Following the EIA “moderate” effects were identified concerning shipping andnavigation as during the construction phase, there will be temporary displacementin relation to established shipping routes. The most significant effects arise frompre-sweeping, route clearance, cable laying and post-laying, and potential formaintenance to the installed cable. The buried cable is not predicted to have animpact upon shipping and navigation.
3.3.45 Embedded mitigations were already in place prior to undertaking the EIA, such assensitive cable routing to avoid major shipping and navigation constraints, suchas anchorage points, and to reduce the coverage of areas known to constitutemajor shipping routes. In order to prevent or minimise potential effects identified,further mitigations measures have been proposed. These are industry standardmeasures including discussion with port authorities in order to avoid schedulingconflicts (i.e. between the Proposed Development and port maintenancedredging), the clear demarcation of the construction area and restricted access tothe eastern mooring zone at “Caen Ouistreham” harbour, the maximisation of
IFA2 EIA SUMMARY
Page 53
cable burial (rather than surface laying with cable protection) in the nearshorearea and ongoing liaison with the local maritime association to increase the safetyof offshore operations. Following the application of these mitigation measures,there are no residual effects to shipping and navigation.
Commercial Fisheries
3.3.46 The commercial fisheries impact assessment was carried out using desk-basedstudy mainly using information issued by private or public sector organisations. Inaddition two further desktop studies were commissioned by specialistconsultancies in relation to commercial fisheries and covered both French andEnglish waters with specific focus on the Baie de Seine area in France. Thesestudies also involved meetings with fisheries representatives.
3.3.47 Following the EIA “moderate” effects were identified concerning commercialfishing activities. During the construction phase, there will be temporarydisplacement in relation to fishing activities in addition to temporary and localisedeffects on water quality from increased turbidity and direct and indirectdisturbance to commercial fish populations. The most significant effects arisefrom pre-sweeping, route clearance, cable laying and post-laying, and potentialfor maintenance to the installed cable. The buried cable is not predicted to havean impact upon commercial fisheries with the exception of cable protection whichwill present a permanent impact in terms of the potential for snagging fishing gear.The decommissioning phase is anticipated to similar but reduced effects to theconstruction phase.
3.3.48 In order to prevent or minimise potential effects on commercial fisheries, furthermitigation measures have been implemented including routing of the cable aroundknown shellfish grounds, the sensitive timing of offshore activities in relation tospawning grounds of commercial fish species (including avoidance of works beingcarried out over the winter period), the minimisation of pre-sweeping operations atsandbanks, the maximisation of cable burial (rather than surface laying with cableprotection) and the preference to use cable burial techniques which limit theproduction of suspended sediments. Following application of the mitigationmeasures there remains a residual impact.
Recreational Users
3.3.49 The assessment is predominantly carried out using desk-based data such asinformation issued by private or public sector organisations in relation to specificrecreational activities.
3.3.50 During cable routing, constraints identified in relation to recreational activitiesoffshore and the areas used for these activities were avoided to minimise impact.During cable installation, there will be temporary displacement in relation torecreational fishing activities in addition to temporary and localised effects on
IFA2 EIA SUMMARY
Page 54
water quality from increased turbidity and direct and indirect disturbance to fishpopulations. The most significant effects arise from pre-sweeping, routeclearance, cable laying and post-laying, and potential for maintenance to theinstalled cable. Recreational activities taking place on the water will also betemporarily impacted due to displacement, however this will affect a localisedarea and therefore is not considered to compromise recreational activities on abroad scale. At the cable landfall, construction is predicted to present a potentialimpact to those recreational activities occurring at the coastline, especially duringthe summer months.
3.3.51 Embedded mitigations were already in place prior to undertaking the EIA, such assensitive cable routing to avoid constraints relevant to recreational activities, forexample the use of popular yachting ways and boat mooring zones. In order toprevent or minimise potential effects on recreational activities further mitigationsmeasures have been proposed. These include ongoing communication with thepublic and the promulgation of information to ensure safety to human activitiesduring construction, the clear demarcation of the construction area and restrictedaccess to the eastern mooring zone at “Caen Ouistreham” harbour, themaximisation of cable burial (rather than surface laying with cable protection) inthe nearshore area, and the sensitive timing of construction works. Followingapplication of the mitigation measures proposed there is no residual impact toboating and yachting activities. There is some residual effect to recreationalfishing activities.
Other Marine Users
3.3.52 The assessment of other marine users included military training areas, aggregatedredging activities, cables and pipelines and energy projects in the offshore andintertidal area. The assessment was undertaken using desk-based data includinginformation issued by private or public sector organisations in relation to specificactivities.
3.3.53 Potential effects to military users and to existing networks are considerednegligible. Whereas potential effects were identified in relation to aggregatesextraction and a marine renewable energy project which are classed as negligibleto minor. Effects considered here include displacement of activities leading topotential loss of revenue for other commercial users, collision risk, damage toexisting infrastructure (e.g. the three existing cables which IFA2 crosses) andpotential effects to sediment dynamics with the potential to affect aggregatesassets.
3.3.54 Mitigation measure in relation to other marine users include ongoing liaison withrepresentative for other marine activities in order to manage scheduling conflicts,the application of a 1 NM buffer zone in respect of aggregate extraction sites, theestablishment of an appropriate burial depth for the cable in affected areas,adherence to agreed cable crossing practices, the avoidance of the military trialperiod, and the careful management of construction and supporting vessels to
IFA2 EIA SUMMARY
Page 55
minimise collision risk with other marine users. Following application of thesemitigation measures, there is no residual impact to other marine users.
Environmental Quality
3.3.55 Potential effects in relation to air and water quality and on the quality of life withinthe study area were considered. This assessment was carried out using desk-based analysis of the available data, such as established databases of waterquality and shellfish resource quality, data from air quality measurement stationsand human activity mapping resources.
3.3.56 The majority of potential effects are predicted in relation to the construction phasein terms of quality of life, however all of these effects are classed as having minorsignificance. Potential effects include typical construction effects such as noise,dust and access to the beach, and also the potential for accidental pollution.Water and air quality are not considered to be impacted by the constructionphase. The installed cable is not predicted to cause any potential effects inrelation to environmental quality.
3.3.57 To reduce the effects of the construction (and the decommissioning phase whichis anticipated to have similar albeit reduced effects as the construction phase), itis proposed that a burial method be used which minimises the release ofsuspended sediments and therefore limits turbidity. In relation to the cablelandfall, it is proposed that during the summer period there should be no overnightworking except for instances where this is considered a necessity.
Cumulative Effects
3.3.58 Potential effects in relation to cumulative effects to the same receptor or group ofreceptors were assessed and the following areas were identified as locationswhere cumulative effects may occur.
The Baie de Seine is important for several groups of marine uses - shipping,access to ports, commercial fisheries, marine aggregates - and is also ofecological importance (ZSC and ZPS).
The Banc de Seine is important for its particular bathymetric andsedimentary characteristics in addition to human related activities such asshipping and moorings.
The central Channel is important for shipping, cables and commercialfisheries.
The coastline is important for its ecological importance as a nursery area andalso for tourism.
IFA2 EIA SUMMARY
Page 56
3.3.59 The majority of potential effects in these areas were mitigated in the initial stagesof the project by routing away from constrained areas and minimising the area ofNatura 2000 sites crossed, in addition to the use of HDD at the landfall. Allpotential cumulative effects here are temporary.
3.4 French Onshore EIA
Introduction
3.4.1 This section provides a summary of the findings of the French onshore EIA foreach environmental topic assessed and provides details of the survey workundertaken to inform the EIA process. There is also a discussion in relation tocumulative and transboundary effects.
Surveys Undertaken
Table 3.4 details all surveys undertaken as part of the French Onshore EIA andwhich chapters these surveys informed.
Table 3.3: Surveys undertaken to inform the IFA2 French marine and intertidal EIA.
Approach to Impact Assessment and Key Findings
Physical Environment
3.4.2 The physical environment in relation to existing underground cables wasassessed in detail in an early stage of the project in order to choose the leastimpactful and the shortest cable route. The initial study was carried out
Survey Date Chapters Informed by Results
Wildlife and Vegetation Survey 2014 and 2016 Flora and Natural Habitats; Amphibians and Reptiles; Bats; Insects;Mammals.
Wetlands Assessment 2015 Wetlands.
Vegetation and Natural HabitatsInventory
2014 and 2016 Flora and Natural Habitats.
Species Inventory 2014-2015 Amphibians and Reptiles; Insects; Mammals.
Bird Survey 2014-2015 Ornithology.
Bat Survey 2015 Bats.
Landscape and visual survey 2015 Landscape
IFA2 EIA SUMMARY
Page 57
considering a wide area of search in order to identify potential corridors withrelatively minor constraints. The physical environment impact assessmentconsidered two scale of study, a large scale assessment corresponding to thewider study area and a more local scale assessment considering the area aroundthe cable route proposed following initial constraints mapping. To inform theassessment, desk-based data has been used including data from a range ofestablished databases and mapping sources.
3.4.3 “Minor” and “Moderate” effects have been identified based on the desk-basedassessment. Those of a moderate significance include the modification ofagricultural land during the construction phase which will affect the agronomicvalue of the soil. Also, construction activities have the potential to disturb astream at Cagny in terms of crossing this watercourse, and also the soilpermeability on the surface. Additional “Minor” effects were predicted, such asaccidental pollution during the works, soil modifications and erosion. Trenchesand drilling will be undertaken sufficiently far from aquifers that there isconsidered to be no risk from contamination. The operational phase is notpredicted to cause any potential effects.
3.4.4 In terms of mitigation measures, in addition to the avoidance of certain constraintsdiscussed previously, 85% of the route has been centred on previouslydisturbed/worked areas (i.e. roads or agricultural tracks), which greatly reduce theProposed Development’s impact on the environment. Further industry standardand best environmental practice mitigation measures proposed include theseparation of the different ground layers when opening and closing trenches tomaintain soil integrity, the establishment of a management plan and anemergency preparedness plan in association with a hydrogeologist in order toprevent and manage any accidental pollution, the avoidance of obstacles (e.g.watercourses) along the route through the use of HDD, covering of trenches whenprecipitation is forecast and reducing the amount of time trenches remain open. Itis also planned that soils the cable route will be reinstated following thecompletion of construction. In respect of the converter station, further mitigationmeasures include the construction of a retention basin and waterproof trenches.Following the application of these mitigation measures, there are no predictedresidual effects.
Nature Conservation Areas
3.4.5 This assessment was undertaken using desk-based data such as records held inrelation to sites designated for conservation importance and supported by therelevant ecological surveys undertaken as part of the EIA.
3.4.6 Six areas of nature conservation (excluding Natura 2000 sites which are coveredby the HRA) are located in proximity to the onshore components of the proposedproject. Three of these hold ZNIEFF status and there is one “Conservatoire duLittoral” site. Potential effects to these sites are considered to be negligible.Despite this, mitigation measures representing best practice are consideredappropriate in relation to Nature Conservation Areas. These include the routing of
IFA2 EIA SUMMARY
Page 58
the cable to minimise potential effects to sensitive sites designated forconservation importance and the reduction of the footprint of onshore installationwork. There are no residual effects in relation to Nature Conservation Areas.
Wetlands Assessment
3.4.7 The wetlands assessment was carried out using desk-based assessment andgroundtruthed by site walk over survey along the proposed cable route.
3.4.8 The wetlands assessment highlighted that the area around the “Cagny”watercourse is particularly sensitive and the potential for pollution represents apotential impact of minor significance. Mitigation measures are proposed underthe RD223 in relation to wetlands situated close to the road. This includes puttingemergency preparedness and response procedures in place in relation toaccidental spills or releases causing pollution during construction involving astoppage of works and containment measures in the event of a spill.
Vegetation and Natural Habitats
3.4.9 The assessment of vegetation and natural habitats was carried out using desk-based assessment and the wildlife and vegetation survey. Key habitat featureswere characterised.
3.4.10 A potential impact of major significance could be caused by the destruction ofhedgerows during construction. Additionally, potential effects of “moderate”significance are predicted comprising the release of invasive species and thedestruction of non-endangered species habitats.
3.4.11 As a result of the significance of the potential effects identified as part of thisassessment a number of mitigation measures have been proposed. Theseinclude the preservation of natural ditches which constitute habitats for protectedspecies, the implementation of a strict perimeter around construction works, theavoidance of certain habitats in relation to use of equipment or machine storageduring construction, regular maintenance of equipment to minimise the likelihoodof pollutant releases, emergency procedures in relation to pollution requiringcontainment and clean-up of affected areas, the presence of appropriate spill kitson site and the requirement for training of site personnel to use these, and therequirement for an ecologist to attend the site during construction in certainsensitive areas. Reinstatement of habitats to their original condition will also beundertaken. Following the application of these mitigation measures, the onlyresidual impact relates to the destruction of hedgerows but these will be replantedwhere possible to reduce impacts as far as possible.
IFA2 EIA SUMMARY
Page 59
Reptiles and Amphibians
3.4.12 The assessment of the natural environment was carried out using desk-basedassessment using sources such as established publically available databases anddetails on the qualifying features of sites of conservation importance andassociated mapping data. This assessment was also informed by the wildlife andvegetation survey in addition to the species inventory undertaken along the cableroute.
3.4.13 No suitable habitat for reptiles was identified during site survey. Suitable habitatfor amphibian species was noted in relation to the network of ditches, however noamphibian species were observed during survey. There are considered to be nopotential effects to reptiles and amphibians during the operational phase or toreptiles during construction. A potential impact relating to the destruction ofhabitat that may be suitable for amphibians during construction are classed asnegligible. Despite this, best practice mitigation measures are proposed includingthe establishment of an effective management plan during construction to preventaccidental pollution and minimise environmental effects. This will include therequirement for an ecologist to attend the site during construction in sensitiveareas, the requirement to maximise installation under existing asphalt to reducethe level of disturbance to previously un-worked land and potential habitat forthese species. Following application of the mitigation measures there are noresidual effects in relation to these species.
Ornithology
3.4.14 A bird survey was undertaken during 2014 and 2015 to cover the summer andwinter periods. The data from this survey was supported by relevant desk-basedsources.
3.4.15 The key areas of importance along the cable route in relation to birds areconsidered to be the northern sections around the Orne Estuary and itssurrounding area in terms of supporting a relatively diverse number of passerines,seabirds and migratory species. There are also populations of gray herons andlittle egrets in this area. Other parts of the cable route present suitable nestinghabitat for a number of species, with the network of ditches and meadowsconstituting popular nesting habitats for lapwing and sedge warbler, and openagricultural land with hedgerows providing suitable habitat for breeding species ofcommon passerines (i.e. yellowhammer, Eurasian bullfinch, blackbird, blackcapand wood pigeon). Destruction of habitat and disturbance to bird populationswere considered in the impact assessment. The majority of effects to bird speciesare considered to be minor, however a moderate impact is predicted in relation tothe disturbance of birds at the site of the converter station. There are no potentialeffects predicted in relation to the buried cable and habitat loss in relation to theconverter station is considered relatively minimal, with the potential for some ofthe vertical structures installed to be utilised by certain species such as common
IFA2 EIA SUMMARY
Page 60
starling, black crow and kestrel. Therefore there are only minor effects predictedin respect of the operational phase.
Bats
3.4.16 In addition to desk-based data, this assessment was undertaken primarily usingdata from the bat survey undertaken on site to inform the EIA.
3.4.17 Species observed during the survey are relatively common. The constructionworks are unlikely to have any impact on the species themselves or of suitablehabitats and hunting areas. No potential effects were identified in relation to theoperational phase of the proposed project. No further mitigation measures areconsidered necessary in relation to bats.
Insects
3.4.18 This impact assessment in relation to insects was undertaken primarily using datafrom the species inventories undertaken on site during May 2014 and March 2015to identify the presence of certain species.
3.4.19 During the site survey it was observed that the most favourable areas for insectsare the hedgerows and ditches along the cable route, however all speciesconsidered to be present are common and none have protected status. There areconsidered to be no/negligible effects to insect species or favourable habitatscaused by construction or during the operational phase of the onshorecomponents in view of the intention to maximise cable burial under existingasphalt to minimise destruction to previously un-worked land and suitable insecthabitat. No further mitigation is considered necessary in relation to insects.
Mammals
3.4.20 This impact assessment in relation to insects was undertaken primarily using datafrom the species inventories undertaken on site during May 2014 and March 2015to identify the presence of certain species.
3.4.21 The cable route in its entirety includes habitats of only a low level of suitability tomammals, either because habitats suffer from a level of degradation or are closeto the road network. No potential effects were identified in relation to mammalsduring either the construction or operational phase, the latter in particular due tothe reinstatement of the site to its original state. No further mitigation isconsidered necessary in relation to mammals.
IFA2 EIA SUMMARY
Page 61
Landscape and Cultural Heritage
3.4.22 Studies have been conducted at a regional scale and a local scale, along theproposed cable route in order to characterise the study area in relation to existinglandscapes, cultural and historical heritage and identify archaeological features,which are known to be numerous in this region. The assessment relied primarilyupon desk based sources such as mapping of archaeological sites and nationallymaintained lists of historic sites and landscapes. Desk-based data was ground-truthed through site visits and photographic evidence.
3.4.23 There is potential for unknown archaeological sites or features to be encounteredduring construction, although it is challenging to quantify the significance of thisimpact. In terms of landscape and visual effects, construction equipment andfacilities will be visible on a temporary basis in addition to access tracks. Duringthe operational phase, the converter station will be visible although the cable willbe entirely buried, therefore effects on landscape are predicted to be “Minor”.
3.4.24 In terms of mitigation measures, archeological surveys are planned to beundertaken at a later stage prior to construction and an archaeological watchingbrief will be maintained during installation of the cable. In order to minimiseeffects the working footprint will be reduced as far as possible and screening inthe form of hedges (600m) will be grown around the converter station.
Human Settlements
3.4.25 All data obtained to inform the assessment constituted desk-based sources suchas data from local authorities, regional schemes and other documentation, inaddition to mapping data.
3.4.26 The project does not require a significant amount of infrastructure to be put inplace during construction, i.e. static buildings, as the site is mobile along the cableroute and is dependent on which section is being installed.
3.4.27 The presence of the onshore cable imposes an obligation on public or privatelandowners to keep the area free of obstruction and to allow access to RTEagents along the entire route, although instances where this would be necessaryare considered unlikely. The project is not likely to have any effects on thedemographics of the towns along the cable route.
3.4.28 In terms of mitigation measures, the cable route generally avoids urbanised areasand 85% of the route is centred on existing roads and tracks in order to reducethe level of affected residential land, therefore any potential effects identified inrelation to human settlements have been reduced at the cable routing stage. Nofurther mitigations are proposed and there is no residual impact in relation todemographics and human settlements.
IFA2 EIA SUMMARY
Page 62
Agriculture and Forestry
3.4.29 All data obtained to inform the assessment constituted desk-based sources suchas data from local authorities, regional schemes and other documentation, andmapping data.
3.4.30 Forestry is virtually absent from the study area and the route typically avoidstransiting forested areas. No potential effects are therefore predicted in relation toforestry from either the construction or operational phase of the project.
3.4.31 During the construction phase, the space and the access requirements will posetemporary and localised potential effects to agriculture production. This impact isconsidered to have “Moderate” significance.
3.4.32 Only 15% of the cable route will cross fields, therefore effects identified toagricultural areas have been reduced at the cable routing stage. Other workingmeasures have been proposed in relation to the separation of different soil layersfor storage during trenching so as not to disturb the integrity of the soils in relationto its future agricultural use. Specific mitigation measures will be agreed with theowners of agricultural land in order to minimise potential effects. Followingapplication of these mitigation measures, there is still the potential for residualimpact to agriculture and it may be that financial compensation to farmers isrequired where necessary and appropriate (to compensate crop damages…),according to the agreement between RTE and the chamber of agriculture ofCalvados.
Industry and Commerce
3.4.33 All data obtained to inform the assessment constituted desk-based sources suchas data from local authorities, regional schemes and other documentation, andmapping data.
3.4.34 All potential effects upon industry and commerce are positive and moderate innature due to the presence of the workforce on site which promotes the use oflocal hotels, restaurants and other local businesses through the provision of extracustom during the construction phase. Local businesses are also likely to beused for certain construction requirements, e.g. plant hire, local quarries etc.
3.4.35 An inter-business forum will be established in partnership with the Chamber ofCommerce and Industry Caen Normandy prior to the commencement ofconstruction to allow communication between the project and the local businessesto develop the potential for local economic benefit from the proposed project.
IFA2 EIA SUMMARY
Page 63
Tourism and Recreation
3.4.36 All data obtained to inform the assessment constituted desk-based sources suchas data from local authorities, regional schemes and other documentation, andmapping data.
3.4.37 During the construction phase, the space and the access requirements will posetemporary and localised potential effects tourism and recreational activities andfacilities such as hiking paths. These effects are considered to have minorsignificance. Access to the beach will be maintained throughout the constructionphase, although parking is likely to be disrupted near to the cable landfall area.
3.4.38 Mitigation measures proposed in relation to tourism assets include maintainingaccess to major tourism sites and the diversion to alternative tracks in relation toaffected hiking tracks. No further mitigation measures are considered necessaryand there is no residual impact to tourism and recreation.
Planning Constraints
3.4.39 This study was undertaken following the desk-based analysis of a number ofrelevant planning documents and schemes.
3.4.40 There is likely to be a positive, minor impact in terms of planning. For example,the town of Bellengreville hosting the IFA2 converter station will be repaid duringthe operation of the interconnector via three types of taxation, i.e. the flat rate taxon network companies, property tax and the territorial economic contribution.
3.4.41 There is the potential for the presence of the installed cable to hinder certainfurther development in the area, such as the opening of new areas of urbanisationor establishment of leisure or transport infrastructure. The presence of theonshore cable also imposes an obligation on public or private landowners to keepthe area free of obstruction and to allow access to RTE agents along the entireroute, although instances where this would be necessary are considered unlikely.The converter station does not affect future use of the site as it will be acquiredoutright by RTE.
3.4.42 In terms of mitigation measures, the cable route generally avoids urbanised areasand 85% of the route is centred on existing roads and tracks in order to reducethe level of affected residential land, therefore potential effects to planningconstraints have been minimised during cable routing.
Transport Infrastructure and Networks
3.4.43 All data obtained to inform the assessment constituted desk-based sources suchas data from local authorities, regional schemes and other documentation, andmapping data.
IFA2 EIA SUMMARY
Page 64
3.4.44 During the construction phase, the space and the access requirements will posetemporary and localised potential effects to, transport networks. Construction inurbanised areas, although limited, will cause environmental effects to roads.Temporary traffic disturbance is unavoidable and may impact some industry likethe sugar factory at “Cagny”, but limitations in terms of work area and theoptimisation of work schedules to reduce time spent in this area will beimplemented in addition to the establishment of alternative routes andpromulgation of information in relation to this in order to minimise effects. Inurban areas, roads will be reinstated following construction, the construction sitewill be cleaned frequently, safety and security best practice measures will beimplemented and night working will be avoided. Following application ofmitigation measures a residual impact remains, however this is temporary innature and will not persist into the operational phase of the proposed project.
Technological Hazards
3.4.45 All data obtained to inform the assessment constituted desk-based sources suchas data from local authorities, regional schemes and other documentation, andmapping data.
3.4.46 The construction of the proposed project may interrupt gas, water and sewagenetworks temporarily, i.e. water supply to the Cagny sugar factory. A “Major”potential impact was identified in relation to technological risks due to existingnetwork crossing and the potential for encountering UXO. Mitigation in relation totechnological risk is considered a high priority therefore protection measures willbe installed during works in compliance with networks operators’recommendations and a UXO survey will be conducted prior to commencement ofconstruction. Following the application of these mitigation measures, there is noresidual impact in relation to UXO.
Nuisance and Amenity
3.4.47 Nuisance here is defined as disturbance from noise, dust and odour, vibration orlighting. All data obtained to inform the assessment constituted desk-basedsources such as data from local authorities, regional schemes and otherdocumentation, and mapping data.
3.4.48 There are potential effects typical of construction in relation to increased noiseand vibration levels, and dust emissions. The route in urbanised areas wasminimised at the cable routeing stage. These effects are considered temporarybut may be of a moderate level. There will be negligible impact during theoperational phase.
3.4.49 Mitigation measures proposed include regular cleaning of the construction site, noworking during night hours and the consideration of construction timing to reducework duration where possible. A noise study will also be undertaken following the
IFA2 EIA SUMMARY
Page 65
commissioning of the converter station. There are considered to be no residualeffects following the application of these mitigation measures in relation topotential nuisance effects.
Health and Safety
3.4.50 All data obtained to inform the assessment constituted desk-based sources suchas socio-economic data from local authorities, regional schemes and otherdocumentation, mapping data and data from air quality measurement stations.
3.4.51 During the construction phase, there is potential for accidents to occur inpopulated areas due to site activities. The distance covered by the cable route inrelation to urban areas has been minimised to reduce the potential for effects tothe human population. Additionally, best practice health and safety measures willbe put in place at the construction site (such as waste management practicesadhering to legislation and best practice, security procedures, the management ofcertain chemicals and gases etc.) and night working will be avoided to reduce therisk of health and safety incidents. Following the application of these mitigationmeasures, there is no residual impact in relation to health and safety.
Cumulative Effects
3.4.52 An assessment of cumulative effects was undertaken. This considered temporaryeffects such as traffic disturbance and access routes and permanent effects suchas disruption to water flow. The following effects were identified, all of which areconsidered to be of minor significance:
Temporary effects:
o Traffic disturbances on traffic will impact agricultural movement.Additionally, construction works will impact on the available space inagricultural fields. It is possible these two effects will lead to additionaleffects on agricultural receptors, although mitigation measures areconsidered to control this impact.
o Traffic disturbance will impact the Cagny sugar factory. Additionally,some of the water pipes to and from the factory may requiretemporary closure. The sugar factory may be impacted from the sumof these two effects.
o However, disturbance to traffic is limited (i.e. 1 or 2 weeks) andconstruction schedule will be established in collaboration with thesugar factory to ensure that these effects do not occur concurrently.Measures will also be taken to reduce the space of impact on theaffected road (RD 225) and to the water distribution network.Therefore, the impact is considered to be minor.
IFA2 EIA SUMMARY
Page 66
Permanent effects:
o Cable installation may disturb watercourses and ground biologyalongside hedge and trees bordered by the project. Moreover,pruning may be required to allow work to go forward which wouldfurther impact on these receptors. However, hedgerows and trees areto be avoided as far as possible and there will be a very low level ofpruning activities considered necessary due to the “open-field”structure of the region. Therefore the impact is considered negligible.
IFA2 EIA SUMMARY
Page 67
4. TRANSBOUNDARY EFFECTS
4.1.1 The Espoo Convention (1991) sets out the obligations of signatories to assess theenvironmental impact of certain activities in a transboundary context. As the IFA2Project crosses the waters of both the UK and France, environmental assessmenthas been carried out in both countries. This summary document provides detailsof the results of each assessment.
4.1.2 Transboundary effects (i.e. the Proposed Development in the UK effectingreceptors in France or vice versa) could be expected in relation to most topicsconsidered in the EIA. Transboundary effects have therefore been assessed as amatter of course throughout the EIA process with effects on receptors consideredin terms of the footprint of the proposed development – the assessment has notbeen limited to national jurisdictions. No transboundary effects are predicted tooccur outside of UK or France jurisdictions.
IFA2 EIA SUMMARY
Page 68
5. SUMMARY AND CONCLUSIONS
5.1.1 EIA has been undertaken for all components of IFA2 in the UK and France tosupport the consent application processes for the project. A HRA has beenundertaken in France and in the UK for presentation to the competent authority.This summary document has been prepared based upon the findings presentedwithin the Environmental Statements arising from the individuals EIAs and HRAs.
5.1.2 Very few of the potential effects identified have been of moderate significance orhigher and in all cases appropriate best practice mitigation measures have beenapplied in addition to embedded mitigation measures already included in theproject design such as routing of the cable to avoid constraints and the use ofappropriate installation techniques. The application of mitigation measures has inthe majority of cases reduced the level of impact to a low level of residualsignificance.
Receptor Summary of effect Mitigation applied Residual significance
Onshore UK
Local views. Some views in the vicinity of the converterstation would experience of moderate or majorto moderate adverse effects in the short tomedium term. In the long term, these effectswould be reduced to minor adverse (due to thematuring of planted trees which would screenviews of the converter station) for all but twoviews which would experience residualmoderate adverse effects.
Landscaping and plantingscheme.
Propertieslocated close tocable installationworks.
Noise from cable installation at Daedalus andChillling may lead to moderate adverse effectsat the nearest noise sensitive receptors.
Best practical mitigation will beused where possible to reduceeffects as far as possible such asuse of electrical items of plantinstead of diesel plant wherepossible, use of soil stock pilesand fencing to attenuate noise andplant and equipment will be shutdown when not in use.
Offshore UK
Oyster beds(currently in adegraded state).
Although the oyster beds are currently verydegraded with only a few individuals present itis possible that installation of the HVAC cablesmay hinder future recovery of these previouslyhealthy and productive oyster beds andtherefore a moderate adverse effectsignificance has been assigned.
Mitigation measures to be definedvia ongoing consultation withSouthern Inshore FisheriesConservation Authority.
Oyster beds (currently in adegraded state).
Offshore France
Flounder, sole,shrimp.
Noise from cable burial may have a moderateadverse effect on these species.
Avoidance of spawning months iftechnically and economicallyfeasible.
IFA2 EIA SUMMARY
Page 69
LAST PAGE
IFA2 EIA SUMMARY
Page 70
The sole responsibility of this publication lies with the author. The European Union is notresponsible for any use that may be made of the information contained therein.