12.4.7.              Contaminated Waste

If contaminated soils are recorded or suspected during the works, then works should cease and advice sought from the CEM. Any contaminated waste material produced in this area must be disposed of appropriately by an experienced company licenced to deal with contaminated waste.

12.5. Outline Water Quality Management Plan

This section provides an overview of what will be included within the Water Quality Management Plan. This covers measures specifically related to water pollution from particulates and sediments in run-off and complements the Outline Pollution Prevention and Contingency Plan.

A Water Quality Monitoring Programme will be implemented before, during and after construction to monitor water quality conditions of watercourses which are in hydraulic connectivity with the Proposed Development. Pre-construction monitoring is proposed to develop a baseline water quality dataset for which the construction and post-construction quality can be compared against to assess any potential impacts. The frequency, duration and monitoring methodology will be agreed with SEPA and ELC.  

Outlined below are recommendations for mitigation measures to be implemented during construction to control water quality impacts. These mitigation measures take due cognisance of the Water Resources Act 1991 (UK Government, 1991) and the Construction Industry Research and Information Association Report C532 (CIRIA, 2006).

Good practice measures set out in the relevant PPGs, or GPPs have been followed. A review plan for PPGs is currently underway by SEPA, Natural Resources Wales (NRW), and the Northern Ireland Environment Agency (NIEA), replacing them with GPPs. GPPs provide environmental good practice guidance for the whole UK, and environmental regulatory guidance directly to Scotland, Northern Ireland, and Wales.

The relevant guidance includes:

• PPG1: General guide to the preventing pollution (EA, SEPA & EHSNI, 2013);
• GPP2: Above ground oil storage tanks (EA, SEPA & EHSNI, January 2018);
• GPP5: Works and maintenance in or near water (EA, SEPA & EHSNI, February 2018);
• PPG6: Working at construction and demolition sites (EA, SEPA & EHSNI, 2012);
• GPP13: Vehicle washing and cleaning (EA, SEPA & EHSNI, April 2017); and
• GPP21: Pollution incidence response planning (EA, SEPA & EHSNI, June 2021).

The following measures will be put in place to prevent pollution to the water environment:

• Any hazardous materials (such as fuels, oils, and chemicals) will be stored in a secure area with suitable secondary containment (e.g., drip trays, bunds);
• Refuelling of plant and machinery onsite would be carried out in a designated area with suitable measures for the containment of any spillage; plant nappies shall be placed around standing plant and diesel pumps to collect leaks;
• All construction staff will receive appropriate training of what to do in the event of a spillage;
• Provision of spill kits on site for both chemical and oil/fuel used on site;
• Machinery will be regularly maintained and checked to minimise the risk of spillage;
• Restrictions will be placed on the use of machinery near water bodies;
• Treatment of any runoff from construction areas with elevated suspended solids prior to discharge. Approval will be obtained from ELC or SEPA, where required, for any discharges to controlled waters. Treatment measures could include perimeter cut-off ditches, settlement lagoons, overland flow and/or settlement tanks;
• Temporary surface water management systems will be installed early in the construction sequencing and carefully managed to prevent localised flooding or pollution of surface and groundwater from silt and other contaminants;
• Wheel wash facilities will be provided for vehicles moving to and from the site at all entry and exit points. Silty water from wheel washes will require appropriate disposal to prevent unacceptable levels of suspended solids entering any nearby surface water bodies. As noted above, any disposal of surface water generated on site during construction to controlled waters will require consent from SEPA. Wheel washing facilities will be located as far from surface waters as practically possible;
• If dewatering is required on any part of the site, pumped groundwater will be disposed of appropriately and any relevant consents obtained;
• The reseeding of cleared land will be undertaken as soon as practicable, to minimise exposed land and the entrainment of sediment by overland flow. This can be managed by ensuring construction plant/materials are stored on hardstanding surfaces where possible. Where this is unavoidable, the Principal Contractor will ensure any compacted soil is loosened as soon as possible following completion of the works; and
• The Principal Contractor will manage and dispose of foul water and sewage effluents from site facilities, complying with GPP 4: Treatment and disposal of wastewater where there is no connection to the public foul sewer, the governmental guidance document on Groundwater Protection, other relevant guidance, and the following measures, as appropriate:

–      Containment by temporary foul drainage facilities and disposal off-site by licensed contractors; and

–      By preference, connection to the local foul sewer system as agreed with the relevant authorities; or where a foul sewer is not present, appropriate treatment and discharge to a watercourse or soakaway with approval from the SEPA, where required. If not permitted, provisions need to be adopted to remove the liquid from site for disposal, such as via tanker.

The following measures will be implemented during construction to minimise the risk of pollution to controlled waters and accord with GPP2:

• Any containers of contaminating substances on site will be leak-proof and kept in a safe and secure building or compound from which they cannot leak, spill or be open to vandalism. The containers will be protected by temporary impermeable bunds with a capacity of 110% of the contents of the largest container or 25% of the total, whichever is greater. Areas for transfer of contaminating substances will be similarly protected.
• All refuelling, oiling, and greasing will take place above drip trays or on an impermeable surface which provides protection to underground strata and watercourses and away from drains as far as reasonably practicable. Vehicles will not be left unattended during refuelling.
• Only construction equipment and vehicles free of oil/fuel leaks which could cause material contamination will be permitted on site. Drip trays/nappies will be placed below static mechanical plant.
• All wash down of vehicles and equipment will take place in designated areas and wash water will be prevented from passing untreated into watercourses and will comply with GPP 13.
• GPP 5 will be followed when carrying out works near water. As far as reasonably practicable, only biodegradable hydraulic oils will be used in equipment working in or over watercourses.
• Appropriate measures to be taken to protect erodible earthwork surfaces.
• The hazards of silt pollution will be emphasised in the Environmental Induction, including examples of recent significant enforcement action.
• No water will ever be pumped directly into a watercourse without appropriate controls and consents; i.e., all water pumped into a watercourse must be treated first to settle or remove suspended solids.
• The minimum area of topsoil will be stripped at any one time.
• The spread will be ‘lipped’ or bunded as it crosses a watercourse to prevent direct run-off. Where necessary silt fencing will be installed.

12.6. Outline Soils Management Plan

This section provides an overview of what will be included in the Soils Management Plan. The SMP will be developed by the Principal Contractor in conjunction with ELC, NatureScot, SEPA, Historic Environment Scotland (HES), and the ECoW. This plan will set out the site and soil specific measures to protect soils present on site.

Outlined below are mitigation measures to be implemented during construction to control soil quality impacts:

• Earthmoving works will be carried out in accordance with BSI Code of Practice for Earth Works BS6031:2009 and an earthworks method statement will be produced where more than 50 m³ of spoil is to be excavated.
• Stripping soil following periods of heavy rainfall will be avoided.
• Areas of exposed ground will be reduced so far as reasonably practicable.
• Top and subsoil stockpiles will be segregated.
• All soils will be carefully handled.
• Stockpiles to reduce erosion losses will be protected so far as reasonably practicable where storage is longer than 6 months. Stockpiles will also be protected from flooding. 
• Traffic will avoid soil stockpiles so far as reasonably practicable.
• Where practicable, reinstating soils following periods of heavy rainfall will be avoided.
• Subsoil will be reinstated to maintain natural drainage patterns and avoid settlement.
• Topsoil will be reinstated by rendering into a loose and workable condition as well as contouring to maintain the profile with the adjacent undisturbed area.
• Effective temporary and / or permanent soil erosion control measures will be implemented.
• Suitable, adequate, and effective control measures will be implemented and maintained to prevent run-off from stockpiles contaminating surface waters.
• Disturbed areas and mounds of topsoil/subsoil will be re-graded to blend with the surrounding landform.

12.7. Outline Habitat Management Plan

The Proposed Development will ensure that, during construction activities, valuable habitat areas are protected or reinstated and, where appropriate, enhanced to ensure opportunities for net gain in biodiversity.

Best practice guidelines (CIEEM, 2018) will be followed throughout the construction of the Proposed Development to protect existing wildlife within the site. This includes obtaining appropriate species licences prior to the commencement of works and implementing mitigation strategies to ensure compliance with relevant wildlife legislation.

Specific requirements for mitigation within the site include standard embedded ecology measures:

• Adverse effects should be avoided or minimised, either through the design of the Proposed Development or subsequent mitigation measures. The Proposed Development has been designed to avoid areas of higher ecological sensitivities wherever possible.
• Where impacts on important ecological receptors cannot be avoided, they should be minimised. Minimisation takes many forms, with subsequent design iteration being tweaked and amended where possible to reduce potential ecological impacts. Minimisation has been achieved in several areas by the proposed design. For example:

–      The onshore cabling will be installed alongside tracks and/or field margins wherever possible to minimise habitat loss and/or disturbance.

–      Proximity to watercourses has been avoided wherever possible.

–      Areas considered to be more sensitive in terms of protected habitats such as semi-natural woodland, wetland habitats, and coastal habitats have been avoided wherever possible.

–      Trenchless technology is to be used as an alternative to open trenching techniques to install sections of the onshore cable including at the landfall within Barns Ness SSSI to minimise habitat loss and/or disturbance.

• Where there are significant residual adverse ecological effects despite the mitigation proposed, these should be offset by appropriate compensatory measures.

A planting scheme will be implemented on the completion of construction at the site. The planting will involve the creation of native grassland, hedgerow and woodland habitats and will be used to screen the margins of the A1 trunk road and surround the onshore substation. The planting scheme will benefit protected species by maintaining and creating linear features used for commuting and foraging. Details of the planting scheme including long-term monitoring and management measures will be provided within a detailed Habitat Management Plan.

Full details of mitigation measures will be provided in a detailed Habitat Management Plan in consultation with NatureScot, ELC and the ECoW prior to construction commencing.

12.8. Species Protection Plan

In consultation and agreement with NatureScot, ELC and the ECoW, the Applicant will develop and implement a Species Protection Plan. Following consent of the Proposed Development, ecological pre-construction surveys will specify the extent of licences, habitats and protected species management plans that might be required for the construction phase of the Proposed Development.

12.8.1.              Overarching Mitigation

To minimise potential for effects on designated sites, protected species and habitats during construction of the Proposed Development, the following measures will be taken:

• Chemicals will be stored securely away from any watercourses (minimum 10 m) and from habitats known to be used by protected species;
• Appropriate signage and segregation of construction vehicles from areas included within the boundaries of designated sites.
• Excavations will be covered at the end of each working day, or alternatively will include a means of escape for mammals which may become trapped (e.g., a ramp at a 45o angle);
• Any temporarily exposed open pipe system/conduits will be capped to prevent mammals from gaining access; All cable ducts will be capped pending cable pull and will be sealed once cable installed.
• Good housekeeping practices (e.g., litter) must be adhered to on-site at all times;
• In keeping with best working practices during construction, speed limits on-site will be restricted to 15 mph to reduce the risk of collisions of site traffic with protected mammal species;
• Should any sightings or signs of protected species not previously recorded on-site be made then all works within 50 m will cease immediately and the Principal Contractor’s CEM and/or ECoW will be contacted for advice;
• The CEM and/or ECoW will regularly check known features such as protected species resting places for signs of activity, note any new features (e.g., badger setts or birds’ nests), and provide mitigation advice accordingly;
• Relevant TBTs will be given by the CEM and/or ECoW on ecology matters, as and when required;
• All staff working on-site will be made aware of the locations and size of any exclusion zones. This information will be disseminated in the form of TBTs by the CEM or ECoW. During these talks the CEM or ECoW may expand upon the exact extent of restrictions, for example highlighting where access to areas is completely prohibited, or where it is not permitted to stop vehicles on routes passing through exclusion zones. All exclusion zones will be clearly marked by the Principal Contractor where possible with the size of the exclusion zone dependent on the species sensitivity (CEM or ECoW will advise on this);
• Subject to a licence issued by SEPA, clearance of dense vegetation should be supervised by the ECoW to ensure that any badger setts or otter resting sites (where clearance works are along watercourses) are identified and protected.
• Clearance of vegetation, including tall rank grassland and ephemeral vegetation should occur outside of the bird nesting season. Where this is not possible vegetation should be searched by the ECoW prior to removal.
• Where night works are unavoidable, the need for artificial lighting will be kept to a minimum and directed away from sensitive receptors. The CEM or ECoW may make recommendations revising the times of working hours at specific locations or times of year as appropriate to avoid disturbance of sensitive receptors;
• Watercourse crossings will be designed according to best practice (CIRIA, 2010). The exact designs for culvert structures and other watercourse crossings will be the subject of consultation with SEPA and other relevant consultees prior to construction, and will be designed to allow the through passage of fish, otters, and other relevant species, while maintaining existing flow conditions and riverbed conditions within each watercourse;
• All culverts will be fitted with mammal ledges to facilitate movement along ditches and through the culverts themselves;
• Newt fencing will be installed to separate the works area from suitable great crested newt habitat to the south of the proposed substation at Branxton. This will protect individual newts by acting as a barrier to movement of newts into the works area. The location, extent and design of newt fencing is detailed within a great crested newt species protection plan (EIA Report Volume 4, Appendix 7.4);
• Stand-off buffers, temporary soakaways, appropriately discharged dewatering, soil stockpiles at appropriate locations, silt fencing and appropriate housekeeping measures to prevent pollution and siltation to water receptors; and
• Pre-construction verification check surveys will be undertaken for protected species, considered to include otter, badger, and bats. If any evidence of protected species is identified, additional mitigation may be identified and implemented.

The Applicant will require its contractors to obtain and comply with the requirements of any wildlife licences, including all protected species licences necessary for construction of the Proposed Development.

In addition to the measures described in other sections, management of construction activities to minimise ecological effects may include:

• Provision of appropriate ecological watching briefs to be implemented during construction works;
• Reinstatement of any areas of temporary habitat loss and any arrangements necessary for displaced species to maintain long term conservation status of those species concerned;
• Restoration and replacement planting (e.g., trees, hedgerows, scrub, grassland etc) to reinstate any retained habitats adversely affected during construction. All sections of removed hedgerows should be reinstated either with semi-mature planting or translocated stools from the removed sections of hedgerow; and use of by-products of construction to enhance mitigation provision.
• Prior to and during construction, there will be consultation between the Applicant, Principal Contractor, SEPA and relevant wildlife organisations, e.g., NatureScot, as appropriate.

12.8.2.              Invasive Non-Native Species

Appropriate construction, handling, treatment, and disposal procedures would be implemented in accordance with the Scottish Government Non-Native Species: Code of Practice[1].

12.9. Outline Construction Traffic Management Plan

An Outline Construction Traffic Management Plan (CTMP) has been prepared with the EIA Report and it is detailed in Volume 4, Appendix 12.1, Appendix D. Prior to construction, a final CTMP will be prepared to provide details of access junctions, routing plans, and safety measures identifies the traffic management measures required to support the Proposed Development. The measures which will be identified will relate to:

• Traffic Management;
• Abnormal Loads;
• Access;
• Construction Traffic Movements; and
• Road Signage.

Generic measures will be discussed with ELC and Transport Scotland and may include:

• the formation of a Traffic Management Group to help advise of progress, issues and feedback public comments;
• measures to ensure the maintenance and condition of public roads, cycleways and public rights of way do not deteriorate due to the construction traffic, including agreement of monitoring arrangements with ELC and Transport Scotland;
• measures to provide for road safety for the public and construction staff during traffic management works and temporary traffic control measures;
• procedures for driver training (e.g., to protect pedestrians and non-motorised traffic) and appropriate use of technology to remove blind spots;
• procedures to be followed for the temporary or permanent closure or diversion of roads, public rights of way or accesses;
• permitted access routes and accesses for construction traffic;
• procedures to address any highway incidents or vehicle breakdowns relating to construction traffic; and
• monitoring requirements.

Prior to the commencement of the works a full CTMP will be produced in consultation with ELC and Transport Scotland.

12.10. Outline Archaeological Management Plan

This section provides an overview of what will be included within the Archaeological Management Plan (AMP).

A professionally qualified archaeological contractor will be appointed to act as an Archaeological Clerk of Works (ACoW) during construction phase. The ACoW will advise on all archaeological mitigation measures and ensure compliance with planning conditions. Construction phase archaeological guidelines will be provided to the Principal Contractor for dissemination to all construction contractors, advising on the need to avoid adverse effects on buried archaeological remains and to inform the ACoW if any suspected archaeological remains are uncovered.

The programme of archaeological works set out in the AMP will be in keeping with best practice outlined in current planning policy and guidelines: Scottish Planning Policy (2014) and PAN 2/2011 Planning and Archaeology (2011) and Chartered Institute for Archaeologists (CIfA) Standards and Guidance. It will also be in keeping with current policy and guidelines on the historic environment:  Historic Environment Policy for Scotland (HES, 2019).  The programme of works will also be designed in relation to the Scheduled Monument Consents Policy (HES 2019b).

A Written Scheme of Investigation (WSI) will be agreed with ELC Archaeology Service (ELCAS).

Appendix 1 Relevant Legislation

[1] https://www.gov.scot/publications/non-native-species-code-practice/