10.6. Potential Cumulative Impacts

There is no anticipated air quality impact at onshore receptors as a result of offshore construction or operation.

Upon review of the consented developments within the ELC planning system, the majority of developments are greater than 500 m from the Proposed Development site boundary and will be complete prior to commencement of the Proposed Development.

Therefore, cumulative impacts on air quality are scoped out of further assessment in the EIA.

10.7. Receptors and Impacts Scoped In and Out of Assessment

Table 10.2 below summarises the potential impacts proposed to be scoped in and out of the EIAR.

Table 10.2:
Summary of Impacts Relating to Air Quality Scoped In () and Scoped Out (x)

Table 10.2: Summary of Impacts Relating to Air Quality Scoped In () and Scoped Out (x)

 

10.8. Scoping Questions to Consultees


  1. CULTURAL HERITAGE
    1.         Introduction

      2. Introduction

    2. CULTURAL HERITAGE Introduction

This chapter provides an overview of the archaeology and cultural heritage context for the Proposed Development. It sets out the proposed study areas for the EIA, an initial appraisal of the baseline within those study areas and identifies additional surveys or studies required to confirm the baseline. The proposed approach to the desk-based assessment and field surveys required is set out and the methodology to be adopted for the assessment of effects is described. An initial appraisal of potential significant effects is provided along with an assessment of what receptors and/or impacts can be scoped out of the EIA.

Initial consultation which has been undertaken with Historic Environment Scotland (HES) is provided in Annex B3.

11.2. Study Area

Two study areas will be used for the assessment:

  • Inner Study Area (Figure 11.1): the Proposed Development Search Area for the Site Boundary, plus a 500 m buffer, will form the study area for the identification of heritage assets that could receive direct effects arising from construction of the Proposed Development. The adoption of a buffer is to ensure that a broad understanding of the archaeological context of the Proposed Development is understood and presented in the EIA.
  • The intertidal zone (between MHWS and MLWS) is included in this study area and also overlaps with the offshore cultural heritage assessment.
  • Outer Study Area (Figure 11.2): a wider study area, extending 5 km from the proposed substation option (consistent with that proposed for the LVIA), will be used for the identification of cultural heritage assets whose settings may be affected by the Proposed Development (including cumulative effects). Views towards any assets identified as having settings sensitive to change will also be considered, even where no visibility is predicted from the asset. The Proposed Development substation ZTV(s) will also be assessed to identify any designated assets beyond 5 km that have settings that may be especially sensitive to adverse effects resulting from the Proposed Development.

The study area will be refined in the EIAR once the final location of the Proposed Development infrastructure has been determined.

11.3. Baseline Environment

A desk-based study has been undertaken to provide an initial understanding of the baseline environment, using online data sources.

11.3.1.    Inner Study Area (Figure 11.1)

There are 14 Scheduled Monuments (SMs) within the Inner Study Area (HES, 2020), 11 of which are cropmark sites, where only buried archaeological remains survive. These include prehistoric settlement enclosures, ring-ditches and other cropmarks, and a fort. One Scheduled Monument, Innerwick Castle, is of late medieval date of which there are upstanding remains.

There are eight Listed Buildings within the Inner Study Area. Six are of Category B and two are of Category C. They include farmhouses and other farm buildings, gate-lodges and a bridge.

Part of a Historic Battlefield site (Dunbar II) falls within the Inner Study Area, to the west of Torness Power Station, but the Proposed Development Search Area for the Site Boundary does not extend into the designated battlefield site. Part of the Dunglass Gardens and Designed Landscape site falls within the Inner Study Area, to the south-east of Torness Power Station, but the Proposed Development Search Area for the Site Boundary does not extend into the designated area of the designed landscape. Part of the Innerwick Conservation Area to the south-west of Torness Power Station falls within the Inner Study Area, but the Proposed Development Search Area for the Site Boundary does not extend into the Conservation Area.

The ELC Historic Environment Record (HER) (ELC, 2020) holds entries for 164 individual identified archaeological sites within the Inner Study Area (as defined above). Sixty-nine of these are cropmark sites identified from aerial photographs and include remains of prehistoric date and of probable post-medieval date; 11 of these cropmark sites are protected as Scheduled Monuments. Seven are probably natural features of little or no archaeological value. The cropmark sites include remains of roundhouses, ring-ditches, barrows, enclosed settlements, enclosures, pits, trackways and ditches. There are also 23 other areas of archaeological interest, identified from geophysical survey work undertaken in connection with onshore works for the NnG Offshore Wind Farm in 2015.

Other archaeological sites recorded in the HER include burial sites of both Bronze Age and Medieval date, a possible stone circle and prehistoric cremation burial site, lithic scatters (Mesolithic date) and artefact find-spots, other prehistoric settlement sites, the site of a second medieval Castle (Thornton Castle), post-medieval building remains and sites of former buildings, industrial remains, agricultural features and remains and military remains of WWII date, including a hurricane fighter aircraft crash site.

In addition to these, there are 27 standing historic buildings recorded in the HER that lie within the Inner Study Area. These include: 15 residential buildings; a railway station; a military airfield and an observation post; a water mill; seven bridges; and Torness Power Station.

Five of the recorded sites lie within the intertidal zone near the Skateraw landfall option and include Skateraw Harbour, and St Dennis’s Chapel graveyard and other finds at Chapel Point. There are no recorded sites within the search area for the Thorntonloch landfall option.

There are also 35 maritime records recorded in the HER, where the allocated grid reference lies within the Inner Study Area. Many of these have imprecise grid references, because of the nature of the recorded event (shipwrecks/losses at sea) and uncertainty around the actual location of wrecks. In some cases, the recorded sites appear to be located on land; but this is because they are mapped to the south-west corner of a grid square (1 km, or in some cases 10 km, square). It is safe to assume that all of the recorded maritime wreck sites are in fact offshore and somewhere along the coastline from Bilsdean Creek, south-east of Thorntonloch, in the south, and Barns Ness, north-west of Torness Power Station, in the north.

The archaeological record, as expressed through the recorded remains, indicate a well settled landscape that includes preserved remains of occupation from the earliest prehistoric period (Mesolithic settlement at East Barns – radiocarbon dated to 7800-8300 BC), with plentiful evidence for occupation in later prehistoric periods (Bronze Age and Iron Age) and extending through the medieval period (Innerwick and Thornton Castles) into modern times (WWII defensive sites and an aircraft crash site).

11.3.2.    Outer Study Area (Figure 11.2)

To inform the scoping report baseline, consideration has been given to identifying designated heritage assets in the wider landscape beyond those expected to be taken forward to the EIA. An initial appraisal therefore identified designated heritage assets within a combined outer study area of 5 km from each of the three substation options, as shown on Figure 11.2 Within that study area, there are:

  • Thirty-seven Scheduled Monuments (SM): including amongst others, Innerwick Castle (SM 773) and forts (SM 5771); French camp fort, Dunglass (SM 3191); Doon Hill Hall (SM 90098) and forts (SM 5764); and, Black Castle promontory fort (SM 5876).
  • Three Conservation Areas: Innerwick, Oldhamstocks and Cockburnspath.
  • Two Gardens and Designed Landscapes: Broxmouth park and Dunglass.
  • Two Historic Battlefields: Battle of Dunbar I (AD 1296) and Battle of Dunbar II (AD 1650).
  • Two Properties in Care (PiC): Dunglass Collegiate Church (SM 13313) and Doon Hill (SM 90098).
  • Seventy-two listed buildings including: eight category A listed (the closest being Thurston Home Farm (LB 7711); Dunglass gazebo (LB 14725); and Dunglass viaduct (LB 14731)) but also including Oldhamstocks Parish Church (LB 146710) and Cockburnspath Parish Church (LB 4129).
  • Forty-three category B listed buildings (several within Dunglass GDL and within the Conservation Areas at Dunbar, Innerwick, Oldhamstocks and Cockburnspath).
  • Twenty-one category C listed buildings.

The above lists are not exhaustive, and a more detailed assessment will be undertaken once a preferred substation option has been identified. The substation ZTV will be used to identify those designated heritage assets where effects on their settings are considered to potentially be significant and consultation will be undertaken with HES and ELC heritage advisors (Archaeology Service/Conservation Officer) to agree those to be taken forward for detailed assessment in the EIA.

An initial appraisal of designated assets beyond the 5 km outer study area found only one designated heritage asset (Ewieside Hill Fort (SM 369), around 6.5 km to the south-east), that will need to be considered for setting impacts.

There are no other designated heritage assets where there would be potential for the Proposed Development to have an adverse impact on their settings. Traprain Law hillfort (SM 755) lies over 15 km to the west of the substation option sites and is screened from view by intervening topography. Tantallon Castle (SM 13326) lies over 15 km to the north-west and beyond Dunbar.

11.3.3.    Baseline Methodology

A further desk-based assessment will be conducted covering the Inner Study Area (including the intertidal zone). The purpose will be to identify all known heritage assets, designated or otherwise, that could be directly affected by the Proposed Development, and to inform an assessment of the archaeological potential of the Proposed Development site.

Sources to be consulted for the collation of data will include:

  • The East Lothian Council Historic Environment Record (HER);
  • Historic Environment Scotland’s on-line GIS Spatial Data Warehouse;
  • National Record of the Historic Environment (NRHE);
  • Historic maps held by National Library of Scotland;
  • Modern aerial photographic imagery available online;
  • Historic Land-Use Assessment Data for Scotland (HLAmap);
  • Any existing geotechnical data, if available; and,
  • Readily accessible bibliographic resources, including any archaeological reports referenced in HER/NRHE records.

Data will be gathered for the Outer Study Area to identify designated heritage assets that may be subject to effects on their settings and to provide baseline information for the assessment of setting effects.

Walk-over field surveys of the preferred cable route alignment corridor and substation options will be carried out once these have been determined. The purpose of field survey will be:

  • to record the baseline character of heritage assets within the preferred cable route alignment corridor and substation options that have been identified through the desk-based assessment; and
  • to identify any other heritage assets not revealed through the desk-based study, and to record their baseline character, condition and heritage value.

Identified sites will be recorded on pro-forma monument recording forms and by digital photography, and their positions (and where appropriate their extents) logged using a Global Positioning System (GPS). The survey data will be compiled in a Geographic Information System and used during further design iteration work and to inform construction phase mitigation work. The results of the survey work will be provided to ELC Archaeology Service (ELCAS), for inclusion in the HER following completion of the planning application.

Site visits to key heritage assets in the Outer Study Area will be carried out, where necessary and in as far as access is possible, to assess the predicted effect of the Proposed Development on their settings. Site visits will include any assets specifically identified by consultees as requiring assessment and those identified through analysis of the proposed substation ZTV, where it is considered, on the basis of professional judgement, that the effect on their settings could be significant.

11.4. Primary Mitigation

The following mitigation will be implemented by the Applicant with respect to cultural heritage and archaeology.

11.4.1.    Design Phase Mitigation

  • Avoidance of identified areas of archaeological constraint where practicable during the design of the Proposed Development including the landfall(s), cable route (and working wayleaves) the substation, access tracks and temporary sites such as construction compounds.
  • Minimisation of visual impacts on designated heritage assets (Scheduled Monuments, Listed Buildings, Conservation Areas, Gardens and Designed Landscapes, Historic Battlefields).
  • Tertiary Mitigation
    1.     Pre-construction Mitigation
  • Trial trench evaluation at areas of archaeological sensitivity which have the potential to be directly impacted by the Proposed Development, as identified through the results of geophysical surveys. The scope of trial trenching requirements would be agreed through consultation with ELCAS. It is expected that the requirement would be in the order of 8% of the Proposed Development footprint (working area/working wayleave) in areas of high archaeological potential areas and 5% in areas of lower potential[5].
    1.     Construction Phase Mitigation
  • A professionally qualified archaeological contractor would be appointed to act as an Archaeological Clerk of Works (ACoW) during the construction phase. The ACoW would advise on all archaeological mitigation measures and ensure compliance with planning conditions.
  • Construction phase archaeological guidelines would be provided to the Principal Contractor for dissemination to all construction contractors, advising on the need to avoid adverse effects on buried archaeological remains.
  • Fencing off/marking out areas of constraint for avoidance during the construction phase would be carried out, where there are upstanding earthwork remains that require preservation.
  • Set piece excavations may be required where heritage assets (including buried archaeological remains) cannot be avoided.
  • Watching briefs/archaeological monitoring may be required in archaeologically sensitive areas during topsoil stripping and construction works as required under planning conditions.
  • Post-excavation analysis and reporting of any new discoveries made during set piece excavations or archaeological monitoring would be carried out to the satisfaction of ELCAS and in compliance with any planning conditions.
    1.     Operational Phase Mitigation
  • Landscaping mitigation would take account of the settings of designated heritage assets in the Outer Study Area. Earthwork bunds and planting can have both beneficial effects (providing natural screening of visibility of the Proposed Development) but can also have adverse effects in some instances by interrupting or severing intervisibility between monuments, where this characteristic is an important aspect of their settings.
    1.     Decommissioning Phase Mitigation
  • A professionally qualified archaeological contractor would be appointed to act as an Archaeological Clerk of Works (ACoW) during the decommissioning phase. The ACoW would advise on all archaeological mitigation measures and ensure compliance with planning conditions.
  • Decommissioning phase archaeological guidelines would be provided to the Principal Contractor for dissemination to all construction contractors, advising on the need to avoid adverse effects on buried archaeological remains.
  • Fencing off/marking out areas of constraint for avoidance during the decommissioning phase would be carried out, where there are upstanding earthwork remains that require preservation.
  • Monitoring Mitigation
  • No post-construction, operational or decommissioning phase monitoring is required in relation to archaeology and cultural heritage.
    1.         Potential Proposed Development Impacts
      1.     Potential Impacts during Construction

      2. Potential Proposed Development Impacts Potential Impacts during Construction

  • Direct impacts on buried archaeological remains (including within the intertidal zone) arising from installation of underground cables, including exposure of remains within a working wayleave along the finalised cable route.
  • Direct impacts on earthwork remains and buried archaeological remains arising from the construction of temporary and permanent access tracks, and from establishment of other temporary sites such as the construction compounds.
  • Direct impacts on earthwork remains and buried archaeological remains arising from construction of the substation.
  • Temporary impacts on the settings of designated heritage assets in the landscape surrounding the substation, arising from works around construction of the substation.
  • Temporary impacts on the settings of designated heritage assets in the landscape surrounding new OHLs, arising from works around installation of new towers and OHLs.
    1.     Potential Impacts during Operation
  • Impacts on the settings of designated heritage assets in the landscape surrounding the substation. Post-scoping consultation will be carried outwith consultees to agree a final list of designated heritage assets to be included for assessment and to agree any visualisation requirements. Any assets identified through appraisal of the Proposed Development ZTVs that lie beyond the proposed 5 km Outer Study Area, or any specifically identified by consultees as requiring consideration, and which have settings considered to be potentially sensitive to change, will be included in the assessment.
  • Impacts on the settings of designated heritage assets in the landscape surrounding new OHLs, that may be required as part of the Proposed Development.
    1.     Potential Impacts during Decommissioning
  • No adverse impacts on archaeology and cultural heritage resulting from decommissioning of the Proposed Development.
  • Beneficial impacts on the settings of designated heritage assets in the landscape surrounding the substation.
  • Scottish Government (2011) PAN 2/2011 Planning and Archaeology.
    1.     Impact Assessment Methodology

The follow guidance will be followed in the assessment of potential impacts and effects:

  • SNH/HES (2018) Environmental Impact Assessment Handbook.
  • HES (2019) Designation Policy and Selection Guidance.
  • HES (2016) Managing Change in the Historic Environment: Setting.
  • Chartered Institute for Archaeologists (2014) [updated 2017] ‘Standard and guidance for historic environment desk-based assessment’.
  • Scottish Government (2013) PAN1/2013 Environmental Impact Assessment.

The effects of the Proposed Development on heritage assets will be assessed on the basis of their type (direct effects, impacts on setting and cumulative impacts) and nature (adverse or beneficial). The assessment will take into account the value/sensitivity of the heritage asset, and its setting, and the magnitude of the predicted impact.

  • Adverse effects are those that detract from or reduce cultural significance or special interest of heritage assets.
  • Beneficial effects are those that preserve, enhance or better reveal the cultural significance or special interest of heritage assets.

Cultural heritage assets are given weight through the designation process. Designation ensures that sites and places are recognised by law through the planning system and other regulatory processes. The level of protection and how a site or place is managed varies depending on the type of designation and its laws and policies (HES, 2019). Table 11.1 summarises the relative sensitivity of heritage assets (including their settings) relevant to the Proposed Development.

Table 11.1:
Sensitivity of Heritage Assets

Table 11.1: Sensitivity of Heritage Assets

 

The magnitude of impact (adverse or beneficial) will be assessed in the categories, high, medium, low and negligible and described in Table 11.2.

Table 11.2:
Magnitude of Impact

Table 11.2: Magnitude of Impact

 

The sensitivity of the asset (Table 11.1) and the magnitude of the predicted impact (Table 11.2) will be used to inform the professional judgement of the potential significance of the resultant effect. Table 11.3 summarises the criteria for assigning significance of effect. Where two outcomes are possible, professional judgement supported by reasoned justification, will be employed to determine the level of significance.


Table 11.3:
Significance of Effects

Table 11.3: Significance of Effects

 

As detailed in Chapter 6, major and moderate effects are considered to be ‘significant’ in the context of 2017 EIA Regulations. Minor and negligible effects are considered to be ‘not significant’.

Historic Environment Scotland’s guidance document, 'Managing Change in the Historic Environment: Setting' (HES, 2016), notes that:

“Setting can be important to the way in which historic structures or places are understood, appreciated and experienced. It can often be integral to a historic asset’s cultural significance.”

“Setting often extends beyond the property boundary or ‘curtilage’ of an individual historic asset into a broader landscape context”.

The guidance also advises that:

“If proposed development is likely to affect the setting of a key historic asset, an objective written assessment should be prepared by the applicant to inform the decision-making process. The conclusions should take into account the significance of the asset and its setting and attempt to quantify the extent of any impact. The methodology and level of information should be tailored to the circumstances of each case”.

The guidance recommends that there are three stages in assessing the impact of a development on the setting of a historic asset or place:

  • Stage 1: identify the historic assets that might be affected by the proposed development;
  • Stage 2: define and analyse the setting by establishing how the surroundings contribute to the ways in which the historic asset or place is understood, appreciated and experienced; and,
  • Stage 3: evaluate the potential impact of the proposed changes on the setting, and the extent to which any negative impacts can be mitigated.

The substation ZTVs for the Proposed Development will be used to identify those heritage assets from which there would be theoretical visibility of the Proposed Development, and the degree of theoretical visibility.

11.6. Potential Cumulative Impacts

Cumulative impacts (both direct and on the settings of designated heritage assets) could result from the Proposed Development, in addition to and in combination with other proposed developments in the vicinity of the Proposed Development.

The assessment of potential cumulative impacts will adopt the tiered approach set out in Chapter 6:

  • Tier 1: A cumulative assessment of the effects to onshore receptors from both onshore and offshore infrastructure of the Project.
  • Tier 2: A cumulative assessment of the Project in combination with other existing or approved developments in the onshore environment.

The cumulative developments to be included in the final assessment will be drawn from those agreed, through consultation with statutory consultees as the Project progresses. Those to be included in the cultural heritage assessment will be agreed through post-scoping consultation with HES and ELC heritage advisors (Archaeology Service/Conservation Officer).

11.7. Receptors and Impacts Scoped In and Out of Assessment

Table 11.4 below summarises the potential impacts proposed to be scoped in and out of the EIAR.

Table 11.4:
Summary of Impacts Relating to Cultural Heritage Scoped In () and Scoped Out (x))

Table 11.4: Summary of Impacts Relating to Cultural Heritage Scoped In () and Scoped Out (x))

11.8. Scoping Questions to Consultees

  • Do consultees agree that the proposed study areas are appropriate to the nature and scale of the Proposed Development?
  • If not, can consultees advise what they would consider to be appropriate in the specific circumstances, providing reasoning?
  • Are there any particular designated heritage assets that consultees consider have settings that are especially sensitive to change relative to the nature and scale of the Proposed Development that require to be addressed through detailed assessment?
  • Do consultees agree with the proposed scope of the assessment: assets to be included/excluded from assessment?
  • Do consultees agree with the potential impacts identified, or do they have any additional potential impacts that should also be considered?
  • Do consultees agree with the proposed embedded mitigation and do they have any additional mitigation to add (or remove), and do they have any specific requirements in respect of design phase mitigation not included in the proposals?
  • Are there any developments or infrastructure schemes which should be taken into account when considering potential cumulative cultural heritage impacts?
    1.         References

      2. References

  • ELC (2020). East Lothian Council Historic Environment Record (HER). Available at: https://www.johngraycentre.org/collections/search?s=*:*&map=1. Digital data extract provided in April 2020.
  • HES (2016). Managing Change in the Historic Environment: Setting. Available at: https://www.historicenvironment.scot/archives-and-research/publications/publication/?publicationId=80b7c0a0-584b-4625-b1fd-a60b009c2549
  • HES (2019). Designation Policy and Selection Guidance. Available at: https://www.historicenvironment.scot/archives-and-research/publications/publication/?publicationId=8d8bbaeb-ce5a-46c1-a558-aa2500ff7d3b
  • HES (2020). Spatial Data Downloads. Available at: http://portal.historicenvironment.scot/spatialdownloads [accessed: June 2020]
  • SNH/HES (2018) Environmental Impact Assessment Handbook. Available at: https://www.nature.scot/sites/default/files/2018-05/Publication%202018%20-%20Environmental%20Impact%20Assessment%20Handbook%20V5.pdf
  • Chartered Institute for Archaeologists (2014) [updated 2017] ‘Standard and guidance for historic environment desk-based assessment’. Available at: http://www.archaeologists.net/sites/default/files/CIfAS%26GDBA_3.pdf
  • Scottish Government (2013) PAN1/2013 Environmental Impact Assessment. Available at: http://www.gov.scot/resource/0043/00432581.pdf
  • Scottish Government (2011) PAN 2/2011 Planning and Archaeology. Available at: http://www.gov.scot/Resource/Doc/355385/0120020.pdf


  1. GEOLOGY, HYDROLOGY, SOILS & FLOOD RISK
    1.         Introduction

      2. Introduction

    2. GEOLOGY, HYDROLOGY, SOILS & FLOOD RISK Introduction

This chapter will consider the potential significant effects of geological receptors, surface water, groundwater and flood risk.

Initial Consultation which has been undertaken with Scottish Environment Protection Agency (SEPA) is provided in Annex B4.

12.2. Study Area

The geology, hydrology, soils and flood risk study area will cover the Search Area for the Site Boundary and any potential effects up to 1 km from the Search Area for the Site Boundary (refer to Figure 12.1).

Efforts will be taken to identify any private water supplies up to 500 m from the proposed infrastructure.

The study area will be refined in the EIAR once the final location of the Proposed Development infrastructure has been determined.

12.3. Baseline Environment

A desk-based study has been undertaken to provide an initial understanding of the baseline environment.

12.3.1.    Watercourses & Waterbodies

The coastal waters at the site are classified by SEPA under the Barns Ness to Wheat Stack coastal water body and are considered to be of Good status (SEPA, 2018).

Thorntonloch Beach is a Bathing waters protected area, classified as being of Excellent status (SEPA, 2018).

The Search Area for the Site Boundary comprises arable agricultural land. There are four watercourses within the Search Area. Dry burn is to the north-western edge of the Search Area, flowing into the sea at the Skateraw landfall option, and was classified by SEPA in 2018 as Moderate quality. Thornton Burn flows west to east through the centre of the site, and out on to Thorntonloch beach. This has a Good status (SEPA, 2018) and is fed by Ogle Burn and Braidwood / Thurston Mains Burn to the south-west of the Search Area for the Site Boundary.

There is a small unnamed watercourse which runs through the Search Area for the Site Boundary from Innerwick to Skateraw and which appears to be an altered watercourse or drainage channel following roads and field boundaries. Another small unnamed watercourse to the south of the Search Area flows from the existing substation to also discharge at Thorntonloch beach.

There is also a small unnamed waterbody present within the wooded area at Skateraw Harbour.

12.3.2.    Groundwater

Groundwater beneath the Search Area for the Site Boundary is situated within Torness coastal aquifer. The aquifer is classified as Good status (SEPA, 2018) and is a moderately productive aquifer.

12.3.3.    Private Water Supplies

The Drinking Water Quality Regulator for Scotland database does not identify any Private Water Supplies within the Search Area for the Site Boundary. Part of the onshore EIA consultation will be undertaken with ELC Environmental Health Officer to identify any private water supplies and if found, these will be assessed appropriately.

12.3.4.    Flood Risk

Review of SEPA’s online Strategic Indicative Flood Maps shows that there are few localised areas across the Search Area for the Site Boundary with potential for surface water flooding. The areas surrounding Dry Burn and Thornton Burn have localised potential for fluvial flooding (although it is noted that these watercourses are highly incised and flood extents largely confined to the channel extents). A network of other unnamed minor watercourses are present within the Search Area for Site Boundary, the fluvial flood extents of these are unmapped by SEPA due to their catchment sizes being below the < 3km2 threshold. The area up to Mean High Water Springs has potential for coastal flooding. Through the EIA consultation process the level of detail and extent of Flood Risk Assessment (FRA) requirements will be established.

12.3.5.    Geologically Designated Sites

Skateraw landfall option is through Barns Ness Coast SSSI and a Geological Conservation Review Site. This is designated for the presence of biologically important habitats and for Lower Carboniferous Limestone which is rich in fossils. This geology is of particular interest as there is an exposed almost complete, though heavily faulted, section through the whole lower limestone group.

The Applicant has engaged in early consultation with SNH to avoid through design the crucial areas of the SSSI.

12.3.6.    Geology

The underlying bedrock to the north-west of the Search Area for the Site Boundary is limestone, argillaceous rocks and subordinate sandstone, of the Lower Limestone Formation, interspersed with Main Hosie Limestone. The main body of the Search Area for the Site Boundary south of Torness Nuclear plant and the A1 trunk road is sandstone, siltstone and dolomitic limestone of the Ballagan Formation.

British Geological data shows that the superficial geology of the majority of the Search Area for the Site Boundary is Glaciofluvial deposits of gravel, sand and silt. The superficial geology around Dry Burn and Thornton Burn is Alluvium deposits of clay, silt, sand and gravel, while the coastal geology is raised marine deposits of Holocene age.

12.3.7.    Baseline Methodology

A desk-based assessment will be carried out to establish the catchment characteristics and baseline geological and hydrological conditions of the Search Area for the Site Boundary. The desk-based review will build on the data already identified and will comprise:

  • further determination of site geology and hydrogeology from maps published by the British Geological Society (BGS);
  • review of existing sources of data relating to the water regime, including SEPA water quality and flood risk data, discharge consents, abstraction licences and identification of other water users;
  • identifying and gathering information on any geologically important sites;
  • identification of Private Water Supplies and review of potential risk; and
  • consideration of site investigation reports (where available).

Consultation will also be undertaken with key stakeholders including SNH, SEPA and ELC Environmental Health Officer.

A site survey will also be undertaken across the Search Area for the Site Boundary. This will include a hydrological survey of watercourses and waterbodies to record key features and characteristics, including, if applicable, potential watercourse crossing locations, potential flood risk from unmapped watercourses (i.e. < 3km2 catchment area), overland flow paths / routes, potential flood risk mitigation opportunities, details to inform surface water and foul water drainage strategies and outfall configurations, and if identified a survey of private water supplies will be undertaken.

12.4. Tertiary Mitigation

12.4.1.    Construction Phase Mitigation

Where reasonably practicable  a 50m buffer will be implemented around all watercourses considered to have continuous flow throughout the year. Where it is not possible to maintain a 50 m buffer e.g. . where a watercourse will require to be crossed, these works will be regulated under the Controlled Activities Regulations (CAR) licensing regime and necessary licences will be sought from SEPA prior to construction works.

A CEMP will include an outline drainage strategy and details of pollution control measures which will be implemented in accordance with the SEPA’s guidance. This will include, but is not limited to:

  • A contact list for emergency services, the relevant environmental regulators, the local water supply and sewerage undertakers, the Health and Safety Executive and specialist clean up contractors.
  • Requirement for the induction of contractors to include a specific session on good practice to control water pollution from construction activities. The responsibility for protecting the water environment will be shared with all staff on the site with an appropriate level of support from construction managers to achieve this.
  • A Construction Method Statement which will detail how surface water arising during construction will be dealt with. This method statement will take into consideration site-specific ground conditions and will be undertaken in consultation with ELC, SNH and SEPA.
  • Abidance by the best practice outlined in the Pollution Prevention Guidelines (PPGs), the Guidance for Pollution Prevention (GPPs) and CAR Regulations.
  • Implementation of temporary SUDS during construction to manage surface run-off which may include cut-off ditches, settlement lagoons/ponds, sacrificial ditches and silt filter fences during construction to manage surface run-off.
  • Management of run-off and discharge water from the excavation sites into sumps where sediment would be allowed to settle, and the drainage waters would be pumped out and discharged via vegetated soakaways to a vegetated area or infiltration trench down gradient of the excavation site. The exact method of site discharge will be confirmed with the SEPA prior to the commencement of construction. These measures will also be designed to reduce soil erosion by controlling discharges from the excavations.
  • Full inspection of temporary construction SUDS regularly, in particular after periods of heavy rainfall. Maintenance will be undertaken in periods of dry weather where practicable.
  • Management of dewatering activities through dewatering permits and method statements. The ECoW will be consulted and agree pumping and associated mitigation measures prior to commencement of works.
  • Prevention of loose material discharging into the local water environment by using appropriate drainage.
  • Monitoring of all work within or adjacent to watercourses or the sea will be by the ECoW.
  • Appropriate construction compounds design, which will include fuel, oil and chemical storage situated on an impervious base with an impermeable bund, waste to be stored in a designated area and removed at appropriate intervals and minimisation of hardstanding where possible.
  • Positioning of interceptor drip trays under any stationary mobile plant to prevent oil contamination of the ground surface or water.
  • Careful consideration will be given to the location of topsoil and subsoil storage areas, ensuring the they are located on flat areas away from the watercourses, or that cut-off drains are placed between the watercourses and the storage areas.
  • Full training on spill kits and absorbent materials and their appropriate use.
  • Regular checks of vehicles for leakages and, with the exception of emergency repairs, all maintenance to be undertaken offsite.
  • Authoring of a method statement for the laying of concrete foundations. It is anticipated that all concrete will be batched offsite, however this will be confirmed at a later date.
  • Any connection to the Scottish Water clean water network or sewage network will be undertaken by appropriately licenced and trained contractors appointed by Scottish Water.
  • All infrastructure will be constructed taking into consideration the 200 year flood event possibilities (i.e. for both watercourses and coastal flooding).

A Water Quality Monitoring Programme (WQMP) will be implemented before and during construction to record the pre-existing water quality conditions and ensure that no deterioration occurs during construction. The WQMP requirements will be agreed with key stakeholders (SEPA / ELC) at the relevant development stage.

The CEMP will contain a Soils Management Plan which will included, but not limited to, the following measures:

  • All earthmoving works will be carried out in accordance with BSI Code of Practice for Earth Works BS6031:2009.
  • An earthworks method statement where more than 50 m3 of spoil is to be excavated.
  • Avoid stripping soil following periods of heavy rainfall, when practicable.
  • Keep areas of exposed ground to a practicable minimum.
  • Segregate top and subsoil stockpiles.
  • Handle soils carefully to minimise potential soil structure damage.
  • Keep temporary stockpile heights as low as possible given space restrictions e.g., 3 m for topsoil and 4 m for subsoil.
  • Minimise run-off from stockpiles by light compaction and at an angle of no more than 45°, use of trenches and locating stockpiles away from drainage systems and watercourses.
  • Protect stockpiles to minimise erosion losses and weed infestation if storage is to be longer than 6 months (e.g., seeding or light compaction).
  • Protect stockpiles (e.g., using berms) from flooding to avoid soil losses.
  • Keep traffic off soil stockpiles, as much as possible, throughout the period of soil storage.
  • Display clear and unambiguous signage to notify site personnel of the presence of different types of soil stockpiles.
  • Avoid reinstating soils following periods of heavy rainfall (i.e., 5 mm or more in a 24-hour period), when practicable.
  • Reinstate subsoil to maintain natural drainage patterns and avoid settlement.
  • Reinstate topsoil by rendering into a loose and workable condition as well as contouring to maintain the profile with the adjacent undisturbed area.
  • Implement effective temporary and / or permanent soil erosion control measures, where necessary.
  • Implement and maintain suitable, adequate and effective control measures to prevent run-off from stockpiles contaminating surface waters.
  • Land clearance and occupation would be limited to the necessary works areas. The site and temporary construction compound will be kept in a tidy and contained condition.
  • Existing trees within the Search Area for the Site Boundary which do not require removal as part of the Proposed Development would be protected during the construction phase for their future retention.
  • Disturbed areas and mounds of topsoil/subsoil will be re-graded to blend with the surrounding landform.
    1.     Operation Phase Mitigation

During operation a SUDS strategy around the permanent infrastructure will be maintained and managed on a regular basis.