Description of main environmental impacts and proposed mitigation

Air quality

There will be a temporary change/reduction in the speed band during the construction phase only due to the implementation of TM. However, there will be no operational changes. TM will likely result in an increase in vehicle emissions due to idling vehicles and increased congestion.

Plant, vehicles, and construction activities on site, such as excavation of concrete foundations will produce dust emissions which may affect local air quality, however, due to the size and scale of the scheme this is not anticipated to be significant.

Best practice and measures as outlined in the ‘Guidance on the assessment of dust from demolition and construction (January 2024)’ published by the Institute of Air Quality Management (IAQM), which includes the following mitigation relevant to this scheme will be followed:

Site layout will be planned (including plant and vehicles) so that machinery and dust causing activities are located away from receptors, as far as reasonably practicable;
Cutting, grinding or sawing equipment will be fitted with or used in conjunction with suitable dust suppression techniques such as water sprays or local extraction, e.g. suitable local exhaust ventilation systems;
Materials that have a potential to produce dust will be removed from site as soon as possible, unless being re-used on site (cover or fence stockpiles to prevent wind whipping);
Drop heights from conveyors and other loading or handling equipment will be minimised;
Vehicles entering and leaving the work area will be covered/ sheeted to prevent escape of materials during transport;
Equipment will be readily available on site to clean any dry spillages, and clean up spillages as soon as reasonably practicable after the event using wet cleaning methods; and
When not in use, plant and vehicles will be switched off and there will be no idling vehicles.

Further measures to minimise emissions will also be followed, such as:

All plant and fuel-requiring equipment utilised during construction will be well maintained to minimise emissions.
Green driving techniques will be adopted, and effective route preparation and planning undertaken prior to works.

No significant air quality effects are anticipated. Therefore, in accordance with DMRB Guidance document LA 105: Air Quality no further assessment is required.

Cultural heritage

The potential for the presence of unknown archaeological remains within the scheme extents is unlikely as original construction of the A90 carriageway would likely have removed any features of archaeological significance, and works are to be restricted to the central reserve.

As the works are contained to the existing carriageway boundary, there are no anticipated impacts to the non-designated features recorded in the scheme surroundings. The following mitigation measure will be in place to reduce the risk of impacts to undiscovered features of cultural heritage interest, and the existing identified features:

Plant and machinery will be stored within the carriageway boundary as far as reasonably practicable. Where areas out with the carriageway are to be accessed, it will be reduced as far as possible, ideally limited to access on foot.

No significant effects are predicted on cultural heritage. Therefore, in accordance with DMRB Guidance document LA 106: Cultural Heritage, no further assessment is required.

Landscape and visual effects

There will likely 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, plant, vehicles and materials will be restricted to areas of made ground on the A90 (carriageway surface), and construction works are programmed to be undertaken overnight for a two-week period. Furthermore, the scheme is not wholly, or partly located in an area designated for its landscape quality.

Upon completion of the works, no residual impacts are anticipated, as once complete the visual appearance will remain largely unaffected, with an upgraded VRS being the only discernible change.

In addition, the following mitigation measures will be in place during works:

Throughout all stages of the works, the site will be kept clean and tidy, with materials, equipment, plant and wastes appropriately stored to minimise any potential impacts upon landscape and visual effects.
Works will avoid encroaching on land and areas where work is not required or not permitted. This includes general works, storage of equipment, plant and parking.

No significant effects are predicted on landscape and visual effects. Therefore, in accordance with DMRB Guidance document LA 107: Landscape and Visual Effects, no further assessment is required.

Biodiversity

Construction activities have the potential to have a temporary adverse impact on biodiversity in the area as a result of vehicle presence and the potential for disturbance to protected species within close surroundings; and potential to pollute habitats from noise and artificial site lighting during night time working.

No INNS were recorded within 500m of the scheme; however, numerous occurrences of injurious weeds (rosebay willowherb and common ragwort) are identified within 500m. Works will however be confined to the trunk road surface, involving works within the central reserve only. Furthermore, there are no earthworks, permanent (or temporary) land-take, accommodation works or site clearance, and there is no requirement to import topsoil. As such, there is limited potential to spread or introduce INNS or injurious flowering plant species.

A HRA has been undertaken due to the potential for LSE to the River South Esk SAC and its qualifying features. It has been assessed that the works will not result in LSE as:

There will be no loss in habitat connectivity as a result of the works as excavation will take place in the gravelled areas within the central highway reservation; and
The works are considered sufficiently separated from the River South Esk SAC, such that no significant disruption or disturbance to its qualifying species is anticipated.

The following mitigation measures will be implemented:

A ‘soft start’ will be implemented on site each day. This involves switching on plant/vehicles sequentially, as opposed to simultaneously to ensure a gradual increase in noise for minimal disturbance.
Site lighting will be directional and aimed away from sensitive ecological receptors including woodland and watercourses.
Plant, vehicles and materials will be contained within areas of engineered ground, and not stored on grass verges as far as reasonably practicable. If required, reinstatement of any damaged areas will be undertaken upon completion of the scheme.
Amey’s Environmental Team will be contacted if:
There are any sightings of protected species on, or within close surroundings of the active works area;
Unforeseen site clearance, or additional construction activities are required; or
INNS are found within the work area.

Please see Road Drainage and the Water Environment section below for further mitigation measures in relation to pollution prevention and control.

With mitigation measures in place, no significant effects are precited for biodiversity. Therefore, in accordance with DMRB Guidance document LA 108: Biodiversity no further assessment is required.

Geology and soils

There is potential for minor adverse impacts to soil quality and disturbance as works require excavation for the removal, and installation of VRS barriers and terminals. However, construction activities are restricted to localised areas within the central reserve within the carriageway boundary and are not anticipated to have an adverse impact on geology and soils.

The following mitigation measures will be in place:

Plant, vehicles and materials will be contained within areas of engineered ground, and not stored on grass verges as far as reasonably practicable to minimise adverse soil impacts such as compaction, erosion and pollution. If required, reinstatement of any damaged areas will be undertaken upon completion of the scheme.
Where excavated soil is to be reused on site, it will be evenly spread to ensure the soil profile is retained throughout the works area.
Weather reports will be monitored prior to and during the works, with all construction activities temporarily halting in the event of predicted high rainfall or wind.
Additional pollution prevention measures as outlined in Road drainage and the water environment section below will also be adhered to during construction.

With best practice mitigation measures in place, no significant effects are predicted for Geology and Soils. Therefore, in accordance with DMRB Guidance document LA 109: Geology and Soils, no further assessment is required.

Material assets and waste

There is potential for impacts as a result of resource depletion through use and transportation of new materials, however, new metal components such as fixings and VRS barriers will contain a percentage of recycled material, and due to the scale and scope of works no significant impacts are anticipated for material assets and waste.

A SWMP will be prepared prior to the works commencing which details how resource use and waste arising from the works will be managed throughout the scheme. This will help control and reduce the amount of waste produced, resulting in less landfilled waste. Furthermore, waste materials will primarily be recycled at a licenced facility, thereby reducing the amount sent to landfill and promoting circular economy practices. All waste will be transported by suitable licenced contractor and have a valid Waste Transfer Note (WTN).

The following mitigation measures will be implemented:

Waste will be stored in suitable containers and covered.
Where possible, different waste streams will be separated at the source.
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, to minimise/prevent the disposal of unused materials.

With mitigation measures in place, no significant effects are predicted for Material Assets and Waste. Therefore, in accordance with DMRB Guidance document LA 110: Material Assets and Waste, no further assessment is required.

Noise and vibration

Construction activities associated with the proposed works, such as excavating have the potential to cause noise and vibration impacts through the use of machinery, such as excavators and post driving rigs, and general construction vehicle presence. The works will take place during night-time working hours for approximately a two-week duration. This potential disturbance will likely impact NSRs adjacent and surrounding scheme extents and will likely increase noise levels from ambient night levels, however, this is not anticipated to be significant due to the scale and duration of the scheme and with mitigation measures in place.

The relevant Best Practicable Means outlined in British Standard (BS) 5228:2009+A1:2014 ‘Code of practice for Noise and Vibration Control on Construction and Open Sites’ will be implemented and followed in order to reduce noise and vibration disturbance. The standard provides specific detail on suitable measures for noise control in respect to construction operations; which includes:

Where reasonably practicable, quiet working methods should be employed, including use of the most suitable plant, reasonable hours of working for noisy operations, and economy and speed of operations.
Effects from noise should be kept to a minimum through the use of appropriate mufflers and silencers fitted to machinery. All exhaust silencers will be checked at regular intervals to ensure efficiency.
Sequencing operations to minimise simultaneous use of high-noise equipment, and a ‘soft start’ to works will be in place, whereby plant, machinery, and vehicles are started sequentially as opposed to simultaneously.
Employ electrically powered equipment where feasible instead of diesel or petrol alternatives.
Ensure regular maintenance of plant and machinery to prevent excessive noise from worn parts or inefficient operation.
On-site construction tasks will be programmed to be as efficient as possible, with a view to limiting noise disruption to local sensitive receptors. Where night-works are to be undertaken, the noisiest works, i.e. the noisiest works such as milling should be undertaken before 23:00 where practicable.

Furthermore, an environmental briefing on Noise and Vibration will be delivered to all site operatives prior to works commencing.

With best practice mitigation measures in place, no significant effects are predicted for noise and vibration. Therefore, in accordance with DMRB Guidance document LA 111: Noise and Vibration and no further assessment is required.

Population and human health

During construction, activities undertaken on site may have temporary adverse impacts on local residents and vehicle travellers as a result of construction presence, and associated noise and delays due to TM. Residential and agricultural property access points are located within the scheme extents, however, access will be maintained or granted where required.

No significant congestion issues are noted during the proposed construction hours; however, increased journey times may occur due to TM measures. These are not considered significant due to works being undertaken overnight, outwith peak traffic hours.

Local residents and road users will be informed of the proposed working schedule, in particular the times and durations of the works. This will include:

Notification via a letter drop issued prior to the works, in particular due to night-time programming and road restrictions;
Pre-construction notice of the works and journey planning information available via a media release and on approach to the scheme extents.

The following additional mitigation measure will be in place:

Construction lighting will consider the need to avoid illuminating surrounding properties to avoid a nuisance at night, and non-essential lighting will be switched off at night.
Angus Council Environmental Health Team have been notified of the proposed works due to the night-time programming.

With mitigation measures in place, no significant effects on population and human health are predicted. Therefore, in accordance with DMRB Guidance document LA 112: Population and Human Health, no further assessment is required.

Road drainage and the water environment

During the works, there is potential for temporary impacts on the water environment. Potential changes in water quality from pollution events (either by accidental spillage of fuels or waste material such as excavated foundations, or by mobilisation of these in surface water) during the works could have a direct or indirect impact on the surrounding water environment.

Field drains and a watercourse is located within 500m, however, no in-water works will take place and there is no requirement for the abstraction or transfers of water from, or discharges to a waterbody. As such, the potential for a direct pollution incident within a waterbody is low.

Due to the like-for-like nature of the VRS replacement works, there is no potential for the works to increase the flood risk of the A90 carriageway or surrounding area.

The following mitigation measures will be implemented:

All operatives will be aware of SEPA’s Guidance for Pollution Prevention (GPP) documents.
The Contractor will implement measures to minimise the risk of debris, dust, sediment, accidental spillages entering the road drainage system. This can be via the use of drain covers or similar to ensure full segregation of the works from the road drainage system.
All debris which has the potential to be suspended in surface water and wash into the local water environment will be cleaned from the site both during and following the works.
All site operatives 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. Spill kits will also be available within all site vehicles and spill kits will be replenished onsite when required.
The Amey control room will be contacted if any pollution incidences occur (24 hours, 7 days a week).
In the event of a pollution incident, SEPA will be notified without delay.
Weather reports will be monitored prior to and during the works with all construction activities temporarily halting in the event of adverse weather or a flooding event.
The works will only continue when it is deemed safe to do so and runoff/ drainage can be adequately controlled to prevent pollution.
All storage areas (fuels, machinery, plant, materials) where required will be located/stored:
Away (>10m) from watercourses and surface water drainage systems; and
Away from areas that see high vehicular movement (as far as reasonably practicable) to prevent damage by collision or extremes of weather.
Fuels stored within a drip tray, bund or other form of secondary containment.

With mitigation measures in place, no significant effects are anticipated on the water environment. Therefore, in accordance with DMRB Guidance document LA 113: Road drainage and the water environment no further assessment is required.

Climate

Construction activities associated with the proposed works have the potential to cause local air quality impacts as a result of the emission of greenhouse gases (GHGs) through the use of vehicles and machinery, material use and production, and transportation of materials to and from site.

The following measures will be implemented:

Where possible, materials and suppliers will be sourced locally to reduce GHG emissions associated with travel distance.
Waste will be disposed at a local waste management facility where possible.
Further actions and considerations for this scheme are detailed in the above Material Assets and Waste section.

With best practice mitigation measures in place, no significant effects are anticipated on Climate. Therefore, in accordance with DMRB Guidance document LA 114: Climate, no further assessment is required.

Vulnerability of the project to risks

The A90 carriageway within the scheme extents is not identified as being at risk of annual flooding (pluvial or fluvial). However, works will still be programmed as far as practicable to avoid periods of adverse weather and rainfall.

The works are contained within the carriageway boundary, so there will be no change in road’s vulnerability to risk, or the severity of major accidents or disasters that could impact on the environment. Operationally, road safety will be enhanced through the upgrading of VRS.

The vulnerability of the project to risks of major accidents and disasters is considered to be low.

Assessment cumulative effects

During construction, activities associated with the works may have minor temporary disturbances such as changes to noise and vibration and air quality. However, these impacts will be temporary in nature and are not anticipated to result in a significant cumulative effect.

Angus Council’s planning portal has not identified any extant planning applications that would result in cumulative effects.

At present, Amey’s North East Current Works has not identified any other works on the A90, or surrounding roads that will be undertaken in conjunction with the scheme highlighted any schemes will be programmed to consider already programmed works, and as such any effect (such as from TM arrangements and potential construction noise) will be limited.

The Scottish Road Works Register has not identified any conflicting works occurring within scheme surroundings.

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