Description of main environmental impacts and proposed mitigation

Air quality

Impacts

TM implemented during the scheme may result in an increase in vehicle emissions through idling vehicles and increased congestion. There is the potential of increased distances due to the lane closures for the duration of works, somewhat mitigated by the lower volumes of traffic at night. This may result in a temporary deterioration in local air quality.
During construction there is the potential for an increase in dust and emissions from plant and machinery. This is likely to cause a slight deterioration in air quality within the local area. These impacts will last for the duration of the works only.
An increase in the use of HGVs during construction will likely have an impact on air quality within the local area.

Mitigation

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:
The site layout will be planned (including plant, vehicles and Non-Road Mobile Machinery (NRMM)) so that machinery and dust causing activities are located away from receptors, as far as reasonably practicable;
Ensure vehicles entering and leaving the work area are covered to prevent escape of materials during transport;
Ensure equipment is 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.
When not in use, plant, vehicles and NRMMs will be switched off and there will be no idling vehicles.
Plant, vehicles and NRMM will be regularly maintained, paying attention to the integrity of exhaust systems to ensure such fuel operated equipment is not generating excessive fumes.
Green driving techniques will be adopted, and effective route preparation and planning will be undertaken prior to works.
Where possible, materials will be sourced locally.

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

Cultural heritage

Impacts

Works are unlikely to physically alter the non-designated features highlighted above due to the small scale, like for like nature of the works.
The works are located on already made ground therefore no impacts are anticipated on undiscovered cultural heritage assets and those non-designated assets identified within the carriageway boundary. The original construction of the A90 and associated infrastructure likely removed any archaeological remains, and the potential for unknown archaeology is considered low.

Mitigation

Vehicles and materials will not be stored or parked on grass verges where possible.
Any access beyond the carriageway will be minimised and ideally limited to foot access.

No significant effects are anticipated to cultural heritage. Therefore, in line with DMRB Guidance document LA 106: Cultural Heritage Assessment, no further assessment is required.

Landscape and visual effects

Impacts

Due to the nature of the works, there will not be any permanent change to the landscape due to the like for like nature of the works.
There will be no operational impacts on visual receptors as works entail the like-for-like resurfacing of the A90 carriageway within the scheme extents.
Visual receptors identified have the potential to be visually impacted by the scheme during construction due to the presence of TM, plant, vehicles, machinery and operatives.
The general setting of the area may be impacted during construction due to the presence of TM, plant, vehicles, machinery and operatives.
The Garden Designed Landscape identified will not be impacted by the works because works are like-for-like in nature and restricted to the carriageway boundary

Mitigation

Plant/machinery/materials will be stored in unobtrusive areas when not in use and will not be stored on grass verges. Works will be contained within the A90 carriageway extents.
Asset installation will be of a minimal visual impact (if any due to the like-for-like nature of the scheme) and will be in keeping with the current setting of the A90 carriageway within the scheme extents.
Visual screening will be used where possible to minimise visual impacts on surrounding receptors.
Where possible, vehicles, plant and machinery will be stored out of sight from nearby visual receptors. All site areas will be well-kept and tidy.

The residual effect on landscape and visual effects is deemed to be neutral. Therefore, in accordance with DMRB Guidance document LA 107: Landscape and Visual Effects no further assessment is required.

Biodiversity

Impacts

The scheme does not have the potential to spread the INNS and Transport Scotland Target Species identified due to works being contained within the pavement boundary.
Activities undertaken onsite could potentially have a temporary adverse impact on biodiversity in the area as a result of construction vehicles and plant onsite which may cause disturbance to local protected species and pollution of habitats with particular regard to noise, vibration, site lighting and air quality.
The ancient woodland won’t be impacted by the works as they are confined to the carriageway boundaries.
The scheme has the potential to impact the River Tay SAC (if uncontrolled) via pollution events as spillages into the surrounding water environment and disturbance from noise / lighting.

Mitigation

Amey’s environmental briefings will be delivered to site operatives prior to construction.
A ‘soft start’ will be implemented on site each day. This will involve switching on vehicles and checking underside for the presence of any mammals prior to commencing works. In addition, there will be a gradual increase in noise levels from plant.
In the event that protected species is noticed on site, works will temporarily be suspended until the animal has moved on. Any sightings will be reported to the Amey Energy Transition & Sustainability Team. The environment team will be contacted for any guidance if required, and the control room will be contacted for environmental record.
Vehicles, plant, machinery and materials will not be stored or parked on grass verges where possible. Where damage occurs, the reinstatement of the grass verge will be carried out.
As part of the Network Management Contract (NMC), Amey, on behalf of transport Scotland, has been asked to keep a record of various target species, including rosebay willowherb and common ragwort. Works will not cause the spread of this species, if works are likely to result in the spread of this species through disturbance, the Amey landscaping team will be consulted.
All site lighting will be directed away from sensitive ecological receptors such as woodland and watercourses.
A HRA has been undertaken to assess the impacts of the scheme upon the aforementioned designated European site. This HRA concluded that significant effects were not likely with standard mitigation measures implemented allowing for the following reasoning:
The habitat area of the designated sites will not be reduced as a result of the scheme.
There will be no long-term disturbance to key species as a result of the scheme.
No habitat or species fragmentation will occur as a result of the scheme.
There will be no reduction in species density as a result of the scheme.
There will be no change in the key indicators of conservation value.
The scheme works will not reduce the ability of the designated sites to cope with climate change.

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

Noise and vibration

Impacts

Construction activities associated with the works have the potential to cause noise and vibration impacts to nearby noise sensitive receptors, through the use of plant, vehicles and machinery during night-time hours.
TS2010 road surfacing is shown to have superior durability and noise reducing features compared to standard road surfacing mixes. Vehicle travellers and nearby local amenity users will benefit from improved road surfacing as a result of the scheme.

Mitigation

Amey’s Noise and Vibration environmental briefing will be delivered to site operatives prior to construction.
Amey’s ET&S team has contacted Perth and Kinross Council’s Environmental Health Team to notify of the works and discuss any noise related concerns, due to night time programming
Site supervisors will monitor the effects of noise and vibration levels during the works and make necessary adjustments to the working arrangements.
On-site construction tasks will be programmed to be as efficient as possible, with a view to limiting noise disruption to local sensitive receptors. The noisiest works will be undertaken before 23:00 where possible.
Effects from noise will 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.
A ‘soft start’ to works will be in place, whereby plant/machinery/vehicles are started sequentially as opposed to simultaneously.

With best practice mitigation measures in place, and due to the works being of a minor, temporary, transient nature, 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

Impacts

There is no requirement for temporary or permanent land take as the site works take place all within the carriageway boundary.
Nearby residents of surrounding settlements may experience travel disruption due to presence of TM, which may lead to increased journey times.
Access to the residential properties located within 300m of the works will not be impacted by the works.
Access to the agricultural fields located adjacent to the A90 may be temporarily impacted due to the TM.
Bus stops, laybys and pedestrian footways within, or adjacent to the scheme extents are likely to be impacted by the works.
Temporary site lighting has the potential to impact local receptors.

Mitigation

Layby closures will be advertised in advance of the works. The scheme manager will contact the local authority regarding the re-routing of bus stops and/or public footways where required. Where alternatives are to be provided, these will be well sign-posted and accessible.
TM restrictions/arrangements and any expected travel delays will be publicised within the local and wider area via radio and letterbox drop, in an effort to minimise disturbance to vehicular travellers and agricultural businesses in the local area.
Temporary site lighting used throughout the scheme will be directional and pointed only at the area of works.
Site specific control measures regarding noise and vibration, landscape and visual effects and air quality can be found in the relevant sections (above).

With best practice 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

Impacts

If not adequately controlled, debris and run off from the works could be suspended in drainage systems. In the event of a flooding incident, this debris may be mobilised and could enter the road drainage having a detrimental effect on the surrounding local water environment.
Potential for spills, leaks or seepage of fuels and oils associated with plant to escape and reach drainage systems and watercourses if not controlled, which may adversely impact the water environment.
Should flooding occur, this may delay the scheduled works.

Mitigation

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 following the works.
Refuelling and storage of fuels and chemicals must be kept 10 metres from drains, watercourses and drain coverings to avoid water pollution.
Appropriate measures will be implemented onsite to prevent any potential pollution to the natural water environment (e.g., debris, dust, and hazardous substances). This will include spill kits being present onsite at all times, and the use of funnels and drip trays when transferring fuel etc.
Visual pollution inspections of the working area will be conducted in frequency, especially during heavy rainfall and wind.
Weather reports will be monitored prior and during all construction activities. In the event of adverse weather/flooding events, all activities will temporarily stop, and only reconvene when deemed safe to do so, and run-off/drainage can be adequately controlled to prevent pollution.
Prior to works commencing, all operatives will be briefed on SEPA’s Guidance for Pollution Prevention (GPP) documents (particularly GPP 1, GPP 5, GPP 6, GPP 8, GPP 21 and GPP 22).
Amey’s Water Pollution Prevention environmental briefing will be delivered to site operatives prior to construction.

Providing all works operate in accordance with current best practice, as demonstrated by SEPA’s Guidance for Pollution Prevention (GPPs), no significant effects are predicted 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

Impacts

GHG emissions will be emitted through the use of machinery, vehicles and materials used (containing recycled and virgin materials) and transporting to and from site.

Mitigation

Local suppliers will be used as far as reasonably practicable to reduce travel distance and GHG emitted as part of the works.
Vehicles/plant will not be left on when not in use to minimise and prevent unnecessary emissions.
Further actions and considerations for this scheme are detailed in the above Material assets and waste section.

With best practice mitigation measures in place, the residual significance of effect on climate is considered to be not significant. Therefore, in accordance with DMRB Guidance document LA 114: Climate, no further assessment is required.

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