Description of main environmental impacts and proposed mitigation
Air quality
During the construction phase, activities undertaken on site could potentially have some minor localised and short-term air quality impacts in proximity to the works. The construction phase will, for example, require a range of ancillary plant and vehicles which will contribute to local dust and air pollutants. The main sources are likely to be dust generated by cold milling in preparation of carriageway resurfacing, as well as exhaust emissions from ancillary plant and vehicles. As a result, there is potential for impacts to local air quality.
However, considering the nature and duration of the scheme, along with implementation of mitigation detailed below, the proposed works’ impacts on local air quality levels during the construction period are assessed to be temporary, minor adverse in magnitude.
Upon completion of the works, no residual air quality impacts are anticipated.
Air quality mitigation measures:
- A water-assisted dust sweeper will sweep the carriageway after dust-generating activities, and waste will be contained and removed from site as soon as is practicable.
- Materials that have a potential to produce dust will be removed from site as soon as possible, and vehicles that remove cold-milled material from site will have sheeted covers.
- Wherever possible, ancillary plant and vehicles will be shut down.
- All ancillary plant and vehicles will have been regularly maintained, paying attention to the integrity of exhaust systems.
- Ancillary plant and vehicles will be switched off when stationary to prevent exhaust emissions (e.g., there will be no idling vehicles).
- Where practicable, if powered generators are required, the use of mains electricity ancillary plant will be considered in place of diesel or petrol alternatives.
- Cutting, grinding, and sawing equipment (if required) will be fitted or used in conjunction with suitable dust suppression techniques e.g., local exhaust ventilation system that fits directly onto tools.
- Regular monitoring (e.g., by engineer or Clerk of Works) will take place when activities that have the potential to impact local air quality are occurring. In the unlikely event that unacceptable dust or exhaust emissions are emanating from the site, the operation will, where practicable, be modified and re-checked to verify that the corrective action has been effective. Actions to be considered include: (a) minimizing cutting and grinding on-site, (b) reducing the operating hours, (c) changing the method of working, etc.
Landscape and visual effects
During construction, there will be a short-term impact on the landscape character and visual amenity of the site as a result of the presence of construction plant, vehicles, and TM. However, people, ancillary plant, vehicles, and materials are restricted to areas of made/engineered ground on the A7, and construction works are programmed to be undertaken at night (four nights). As such, the visual impact of the works will be somewhat reduced.
Considering the nature, duration, size, and scale of the scheme, and with implementation of mitigation detailed below, impacts on landscape and visual effects are assessed as temporary, negligible adverse in magnitude.
Upon completion of the works, no residual impacts on landscape and visual effects are anticipated e.g., when complete the visual appearance will remain largely unaffected, with a renewed road surface being the only discernible change.
Landscape and visual effects mitigation measures:
- The site will be monitored regularly for signs of litter and other potential contaminants, and litter will be removed before and after works take place.
- The site will be left clean and tidy following construction.
- Where possible, construction vehicles will not be left in places where soil or vegetation can be damaged. If damage to road verge occurs it will be lightly cultivated or graded (upon completion of the works) to allow natural recolonization by local species and promote integration with existing landscape character.
Biodiversity
The works are located directly above the River Tweed SAC at the northern end of the scheme extents and as such a HRA was undertaken which could not rule out the potential for Likely Significant Effects (LSE) on the River Tweed SACs qualifying features. An Appropriate Assessment (AA) was therefore undertaken which concluded that following the implementation of mitigation measures (all of which are listed below, such as lighting will be screened and positioned to avoid Ale Water and its associated riparian woodlands), the works would not result in an adverse effect on site integrity (AESI) to any of the qualifying features of the River Tweed SAC.
The works will result in a temporary short-term increase in noise levels which may cause disturbance to local wildlife, if present in the vicinity of the works. The works will, for example, require a range of ancillary plant and vehicles which will emit noise and create potential disturbance. The works will also require delivery of materials and the presence of personnel to facilitate the improvements to the road surface. However, the number of construction vehicles and construction operatives required on site is low given the scale and scope of works. In addition, any species in the area are likely to be accustomed to noise and visual disturbance pertaining to vehicle movements on the A7, and the scheme is of limited duration (four nights). The potential for significant species disturbance within the area of likely construction disturbance is therefore somewhat diminished.
Rosebay willowherb, an invasive native perennial, is recorded within the verges surrounding the scheme. However, all works will be restricted to resurfacing of the existing A7 carriageway, and as such, providing the mitigation detailed below is adhered to there is limited potential to spread or introduce INNS, invasive native perennials, or injurious flowering plant species.
Considering the nature, duration, size, and scale of the scheme, and with implementation of mitigation detailed above, the proposed works’ impacts on biodiversity throughout the construction period are therefore assessed to be temporary, minor adverse in magnitude.
Upon completion of the works, no residual impacts are anticipated in relation to biodiversity.
Biodiversity mitigation measures:
- All site personnel will be made aware of the location and sensitivity/protected status of the River Tweed SAC.
- Where possible, artificial lighting used during night works will be sufficiently screened and aligned so as to ensure that there is no direct illumination of neighbouring habitat (e.g., Ale Water, riparian woodland etc.) to ensure minimal impact on nocturnal species.
- Given the records of a protected species within the scheme extents, Toolbox Talk TTN-139 ‘Protected Species’ will be briefed to all staff prior to the commencement of works.
- Given the presence of rosebay willowherb (an invasive native perennial), within the verge of the scheme extents, Toolbox Talk TTN-009 ‘Working with Injurious Weeds & Invasive Plants’, will be briefed prior to works commencing.
- The works are not permitted to disturb or destroy any active birds’ nests. If an active bird’s nest is identified onsite that will be impacted by works, BEAR Scotland’s Environmental Team will be contacted.
- All site workers will have received adequate training relevant to their role prior to working on the site, including specific environmental inductions and ‘toolbox talks’ as required.
- Site personnel will remain vigilant for protected species and will not approach or touch any animals seen on site. Any sightings of protected species will be reported to BEAR’s Environmental Team. Should a protected species be encountered or move within 50m of the active works, works will be temporarily halted until the animal(s) move at least 50m away from the construction site, or until BEAR’s Environmental Team can provide advice.
- The Contractor will employ ‘soft start’ techniques for all noisy activity to avoid sudden and unexpected disturbance during works. Each time the activity is started up after a period of inactivity, the noise levels will be gradually increased over a period of 30 minutes to permit animals (including birds) to move away from the disturbance.
- All equipment stored onsite, if necessary, will be checked at the start of each workday to ensure mammal species are not present. Any storage containers/plant within the compound will also be secured overnight to prevent exploration by mammal species. Any areas where an animal could become trapped (e.g., storage containers) will also be covered at the end of each working day.
- People, ancillary plant, vehicles, NRMM and materials will be restricted to areas of made/engineered ground (as much as is reasonably practicable). If during works unforeseen access to the surrounding environment is required, works will cease in this area and BEAR Scotland’s Environmental Team will be contacted to allow consideration of potential environmental effects.
- BEAR Scotland’s Environmental Team will be contacted to allow consideration of potential environmental effects if:
- unforeseen site clearance is required,
- unplanned works are be undertaken out with the carriageway boundary,
- there is any deviation from the agreed plan, programme and/or method of working,
- nesting birds are found onsite.
- BEAR Scotland’s Control Room will be contacted if there is a pollution incident.
Material assets and waste
Minimising impacts arising from construction materials are focussed upon making the most efficient use of materials onsite to reduce the need for imported primary materials and minimise the creation and disposal of waste through (i) reduction, (ii) re-use, and (iii) recycling. Potential impacts have been assessed for both the construction and operational phases of this scheme. It is anticipated that most material impacts are likely to arise during construction, though long-term residual impacts could occur post construction during the operational phase e.g., during the disposal of materials arising from routine maintenance operations.
However, the detailed design will reduce the requirements for primary materials e.g., the carriageway surfacing, and subbase will be carefully considered to minimise the requirements for importing primary material. Materials will also be derived from recycled, secondary, or re-used origin as far as practicable within the design specifications to reduce natural resource depletion. Specifying TS2010 surface course also allows a wider array of aggregate sources to be considered when compared to typical stone mastic asphalt (SMA). As a result, the use of TS2010 should reduce the usage of imported aggregates and increase the use of a wider range of sustainable aggregate sources. The design life for the TS2010 surfacing is also estimated to be 20 years. The enhanced durability of TS2010 therefore reduces reoccurring routine maintenance and associated levels of traffic disruption to this section of road over the period.
Considering the nature, duration, size, and scale of the scheme, and with implementation of the mitigation detailed below, the proposed works’ impacts on material assets and waste throughout the construction period are therefore assessed to be temporary, negligible adverse in magnitude. Upon completion of the works, no residual impacts are anticipated on materials or waste.
Material assets and waste mitigation measures:
- The waste hierarchy (Reduce, Reuse, Recycle and Dispose) will be employed throughout the construction works.
- Good materials management methods (e.g., ‘just-in-time’ delivery) will be implemented wherever possible.
- The Contractor will comply with all ‘Duty of Care’ requirements, ensuring that any surplus materials or waste are stored, transported, treated, used, and disposed of safely without endangering human health or harming the environment. Waste transfer notes and/or waste exemption certificates (if required) will also be completed and retained.
- All road planings will be managed in accordance with SEPA Position Statement WAS-PS-07 (Low Risk Waste Activities 3) and recycled in line with SEPA Guidance WAS-G-DEF-05 on End-of-Waste for Recycled Aggregates. The Contractor will be responsible for ensuring full compliance with these requirements.
- Designated areas will be identified within which all materials and personnel, including construction compounds, where necessary, will be contained to limit environmental disturbance during construction works. This will include a designated area (if required) for segregation and reuse of waste materials.
- The selection of areas for materials stockpiling will avoid sensitive locations such as road drainage. Stockpiled materials with leachate potential, for example, will be stored away from road drainage to prevent cross-contamination with other materials, wastes, or groundwater.
- Materials will be stored with the appropriate security to prevent loss, theft, or vandalism.
- All temporary road signs and traffic cones will be removed from site on completion of works.
- Wastewater from welfare facilities (if required) will be subject to effluent treatment followed by tanker removal.
- If hazardous substances are used onsite, each substance will be subject to assessment under the Control of Substances Hazardous to Health (COSHH) Regulations 2002. Hazardous substances will also be clearly labelled, and disposed of, in line with relevant waste regulations. Special waste will also not be mixed with general waste and/or other recyclables.
Noise and vibration
Activities undertaken on site could potentially have some localised and short-term noise impacts in proximity to the works. The road works will, for example, require a range of ancillary plant and vehicles for cold milling in preparation for carriageway resurfacing. Noise will also be generated by using breakers (jackhammers), chipping hammers, and rollers, etc. As a result, there is potential for noise and vibration effects to residential properties within the local area, the closest of which is located approx. 25m east of the scheme extents.
However, the works are not located within a CQA, and while works will be undertaken over four nights, the aim will be to complete the noisiest works by 23:00. In addition, the proximity of road space suggests that local residents have a degree of tolerance to noise and disturbance.
The road surface is in a poor condition, with a series of defects. Replacing the life-expired surface course with TS2010 road surfacing affords the benefits of a reduction in mid-to-high frequency traffic noise and a reduction in the ground vibrations. As a result, upon completion of the work, noise associated with the movement of vehicles on the trunk road should decrease post-construction.
Considering the likely sources of noise and vibration, with the nature, duration, size, and scale of the scheme, and with implementation of the mitigation detailed below, it is unlikely that noise and vibration associated with the works will lead to significant impacts, disruption and/or complaints. The proposed scheme is therefore anticipated to result in temporary, minor adverse noise impacts.
Noise and vibration mitigation measures:
- The local authority environmental health department will be notified of nighttime working by BEAR Scotland’s design engineer.
- Where possible, the noisiest work operations (e.g., cold milling, using breakers (jackhammers), chipping hammers, use of rollers, etc.) will be completed before 23:00.
- In proximity to Ale Water ‘soft start’ techniques will be employed for all noisy activity to avoid sudden and unexpected disturbance during works. Each time the activity is started up after a period of inactivity, the noise levels will be gradually increased over a period of 30 minutes to permit animals to move away from disturbance.
- If unacceptable noise is emanating from the site the operation will, where possible, be modified and re-checked to verify that the corrective action has been effective. Actions to be considered include (a) minimizing cutting and grinding on-site, (b) reducing the operating hours, (c) repositioning equipment, (d) changing the method of working etc. Corrective actions will be actioned through the non-conformance reporting procedure, which ensures a root-cause analysis is carried out on each incident. The non-conformance procedure also ensures that appropriate corrective and preventative action measures are agreed and implemented in a timely fashion with all parties, and are recorded and actioned through to closeout, and fully auditable and traceable.
- Ancillary plant and vehicles with directional noise characteristics will (where practical) be shut down in intervening periods between site operations.
- The use of paving breakers (jackhammers), chipping hammers, etc. will be avoided (except where there is an overriding justification), and if used will be fitted with mufflers or silencers of the type recommended by the manufacturer.
- Drop heights from vehicles will be kept to a minimum to minimise noise when unloading.
- All ancillary plant and vehicles used onsite will have been regularly maintained, paying attention to the integrity of silencers and acoustic enclosures.
- All compressors will be ‘sound-reduced’ models fitted with properly lined and sealed acoustic covers which will be kept closed when in use.
- HGV and site vehicles will be switched to the minimum setting required by HSE and, where possible, will utilise ‘broadband non-tonal’ or ‘directional sound reversing’ alarms. Speed limits will also be reduced through the works.
Population and human health
During construction, activities undertaken on site have the potential to have temporary adverse impacts on local residents and road users. A number of residential properties lie within 300m of the scheme and as such, there is potential for impacts to local residents in the form of noise/vibration impacts, visual disturbance and delays due to traffic management. However, TM will only be in place for four nights (when traffic flows will be at a minimum), as such no congestion issues are noted during the proposed construction hours. Providing mitigation measures detailed below and those listed within the noise and vibration section are adhered to, the impacts are assessed to be somewhat reduced.
There is one pedestrian footpath bordering the A7 southbound carriageway at the northern end of the scheme extents. However, all works will be confined to the A7 carriageway and therefore will be separated from the footpath.
Considering the nature, duration, size, and scale of the scheme, and with implementation of the mitigation described above, impacts on population and human health are assessed as temporary, minor adverse in magnitude.
Upon completion of the works, there will be a beneficial impact in relation to population and human health due to the improvement of usability and safety provided by the new carriageway surface and reconstructed carriageway.
Population and human health mitigation measures:
- Construction lighting will take into account the need to avoid illuminating surrounding properties to avoid a nuisance at night, and non-essential lighting will be switched off at night.
- Advanced signage will be strategically placed on the trunk road to notify stakeholders of the road closure and diversion at least seven days in advance.
- Where appropriate, a communication strategy (e.g., social media, consultation with local authority and other stakeholders, letter drop (for night-time works), etc.) will be initiated to keep local residents and businesses informed of the proposed working schedule, particularly the times and durations of noisy construction activities. The communication strategy will also provide a 24-hour contact number for the BEAR Scotland Control Room.
- A Traffic Management Plan (TMP), which includes measures to avoid or reduce disruption to road traffic, will be produced in accordance with the Traffic Signs Manual (Department of Transport 2009). The TMP will ensure that there is no severance of community assets, access routes or residential development.
Road drainage and the water environment
During resurfacing works, there is potential for temporary adverse impacts on the water environment. Potential changes in water quality e.g., from pollution events (either by accidental spillage of sediments, particulate matter, chemicals, fuels or by mobilisation of these in surface water caused by rain) during works have the potential to have a direct or indirect effect on surrounding waterbodies, such as ‘Ale Water’ (ID: 5236), which flows beneath the northern end of the A7 carriageway boundary.
However, given the restriction of the works to the A7 carriageway, the potential for a direct/ indirect pollution incident to a waterbody is considered to be unlikely e.g., experience gained from BEAR maintenance schemes elsewhere on the network has shown that where standard best working practice is adopted (e.g., adherence to SEPA GPPs, utilisation of drain covers or similar, etc.), water quality is protected.
Considering the nature, duration, size, and scale of the scheme, and with implementation of the mitigation detailed below, the proposed works’ impacts on the road drainage and water environment are assessed as temporary, negligible adverse in magnitude.
Upon completion of the resurfacing and reconstruction works, no residual impacts are anticipated in relation to the road drainage and water environment.
Road drainage and the water environment mitigation measures:
- All site operatives will be made aware of the proximity and sensitivity of Ale Water.
- No work has been identified that would require entering a waterbody. If such a need were identified onsite, BEAR Scotland’s Environmental Team will be contacted (before works commence) to allow consideration of potential environmental effects.
- The abstraction or transfers of water from, discharges to, or the washing of tools in surface waterbodies will not be permitted.
- The Contractor will implement measures to minimise the risk of sediment or accidental spillages entering the road drainage system e.g., prior to works commencing any roadside gullies within 10m of work activities will be protected (e.g., utilisation of drain covers or similar) to ensure full segregation of the works from the road drainage system. The Contractor will inspect these periodically to ensure that they have not been removed, damaged, or interfered with and they will be cleaned of silt and debris as necessary.
- All site personnel will be made aware of site spillage response procedures and in the event of a spill, all works associated with the spill will stop, and the incident reported to the Site Supervisor. Small spills that did not leave the site boundary and are cleaned up without material environmental harm or residual environmental impact would most likely not be required to be notified to SEPA or other authorities. However, all such incidents will be recorded and reported to BEAR Scotland’s Environmental Team. In the event of a ‘serious incident’, SEPA will be notified without delay. Such notification will include: (i) the time and duration of the incident, (ii) a description of the cause of the incident, (iii) any effect on the environment as a result of the incident, and (iv) any measures taken to minimise or mitigate the effect and prevent a recurrence.
- All waste, vehicles, ancillary plant, NRMM and fuels will be stored in the compound(s) or laydown area and will be secured and located, if space is available, at least 10m from drainage entry points and Ale Water, in order to comply with GPP 5 ‘works and maintenance in or near water’. Refuelling will only be undertaken at designated refuelling areas (e.g., on hardstanding, with spill kits available, and >10m from drainage entry points and Ale Water, where practicable). Spill kits will also be available within all site vehicles and spill kits will be replenished onsite when required. Only designated trained and competent operatives will be authorised to refuel plant. Generators, and other ancillary plant, where there is a risk of leakage of oil or fuel, will have internal bunding or will have a secondary containment system placed beneath them that meets 110% capacity requirements. Containment systems will also be emptied regularly. All waste, vehicles, ancillary plant, and fuels will also be stored in a manner that ensures they are protected from damage by collision or extremes of weather.
- Appropriate measures will be implemented during resurfacing operations to limit the potential for wastes (i.e. road planings) and materials (i.e. new asphalt) to enter any gullies present on site. On completion of resurfacing and reconstruction operations, any gullies present on site will be visually checked to ensure they have not become blocked as a result of the scheme.
- Regular visual pollution inspections of the designated laydown area and work site (particularly near road drainage entry points) will be conducted (e.g., site walkover by engineer or Site Supervisor), especially during periods of heavy rain.
- All vehicles onsite will have been regularly maintained, paying attention to the integrity of oil tanks, coolant systems, gaskets etc. A checklist will be present to make sure that the checks have been carried out.
Climate
BEAR Scotland, working on behalf of Transport Scotland, undertake carbon monitoring of major projects and operational activities. Emissions from activities are recorded using Transport Scotland’s Carbon Management System. BEAR Scotland also undertakes resource efficiency activities to manage and reduce emissions contributing to climate change. The works will also extend the maintenance intervals required for future works. In doing so, the service life of the trunk road is also extended.
During works there is potential for impacts as a result of the emission of greenhouse gases through the use of equipment, vehicles, material use and production, and transportation of material/waste. However, considering the nature, duration, size and scale of the scheme, and the mitigation detailed below, the risk of significant impacts to climate are considered to be negligible and adverse in magnitude.
Upon completion of the proposed scheme no residual impacts are anticipated on the climate.
Climate mitigation measures:
- Use of warm mix asphalt as standard.
- Local contractors and suppliers will be used as far as practicable to reduce fuel use and greenhouse gases emitted as part of the works.
- BEAR Scotland will adhere to its Carbon Management Policy.
- Where possible, waste will be removed to local waste management facilities.