Description of main enviromental impacts and proposed mitigation

Air quality

Construction activities associated with the proposed works may temporarily impact local air quality in the surrounding area and pose a nuisance to nearby receptors. Construction activities will likely emit dust and particulate matter into the atmosphere, such as during milling of the carriageway surface. Furthermore, there will likely be an increased HGV and plant presence along this section of the carriageway during the construction period.

TM will likely cause delays, increased congestion and increased traffic emissions.

Post construction there will be no change to traffic flow characteristics (e.g. traffic composition, speed or flows).

Given the nature and scale of the works and the following mitigation measures, the risk of significant impacts on air quality is considered low. Any impacts will be temporary, for the works duration only.

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;
Materials that have a potential to produce dust, such as excavated material, 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.

The following additional mitigation measures will be implemented:

When not in use, plant and vehicles will be switched off and there will be no idling vehicles.
All plant and fuel-requiring equipment used during construction will be well maintained to minimise emissions.

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

No designated cultural heritage features are identified within the scheme extents, with the closest asset, a scheduled monument located 175m from the scheme extents. There are no anticipated impacts to the identified designated and non-designated features as no land acquisition is required, and works are contained to the existing carriageway surface. Furthermore, vibration effects from the scheme are not anticipated to be significant due to the nature of the works.

Original construction of the A90 carriageway and associated infrastructure is likely to have removed any archaeological remains that may have been present. Therefore, the potential for the presence of unknown archaeological remains in the study area is low, with works restricted to the trunk road boundary.

The following mitigation measures will be in place:

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 and ideally limited to access on foot.

No significant effects are anticipated to 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 nine working days, during overnight hours.

The works are not anticipated to impact the range, or sensitivity of views, or level of screening from any visual receptors. Upon completion of the works, no residual impacts are anticipated, as once complete the visual appearance will remain largely unaffected, with the improved road surface being the only discernible change.

The following mitigation measures will be in place:

Throughout all stages of the works, the site will be kept clean and tidy, with materials, equipment, plant and wastes appropriately stored, reducing the landscape and visual effects as much as possible.
Works will avoid encroaching on land and areas where work is not required or not permitted. This includes general works, storage of equipment/containers and parking.

No significant effects are anticipated upon the 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 to disturb protected species from noise and artificial site lighting during night time working.

No invasive plants have been recorded within the scheme extents. Furthermore, there is no 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.

There is no risk of direct pollution to surface watercourses, however there is a risk of indirect pollution to aquatic habitats from construction activities such as milling, especially if pollutants, sediment, or debris enter nearby drainage systems during periods of heavy rainfall (see Road Drainage and the Water Environment section for further details).

A HRA has been undertaken due to the potential for likely significant effects (LSE) to the European designated sites and the qualifying features. No direct impacts are anticipated to the designated sites, with the HRA concluding no LSE to the designated areas as:

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.

The following mitigation measures will be in place:

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, such as trees lining the carriageway.
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.
Should a protected species be encountered or move on site, works will be temporarily stopped, and Amey’s Environmental Team will provide advice.
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

Works are contained to engineered layers of the existing carriageway, and as such there is limited potential for soil disturbance.

In the absence of mitigation including pollution prevention control measures there is potential for soils to become polluted from the accidental spillage or leakage of fuels or oils from plant and machinery. However, any potential impact is not significant and does not carry the potential to affect the overall function or quality of the soil resource.

The following mitigation measures will be in place:

Vehicles 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. 
Additional pollution prevention measures as outlined in the Road Drainage and the Water Environment section below will also be adhered to during construction.

With mitigation measures in place there is no significant effect anticipated on 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, primary materials such as aggregates, however, the binder and base courses used for resurfacing will contain a percentage of recycled material.

As TS2010 surfacing has increased resilience to defects and design life than other stone mastic asphalt (SMA) products, the requirement for maintenance of this section of road is reduced.

There is potential for impacts with regard to pollution from materials and wastes if they are not appropriately managed.

The following regulatory requirements will be adhered to:

A Site Waste Management Plan will be prepared prior to the works which will detail 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.
The Contractor is responsible for the disposal of road planings, and this will be registered in accordance with a Paragraph 13(a) waste exemption issued by the Scottish Environment Protection Agency (SEPA), as described in Schedule 3 of the Waste Management Licensing Regulations 2011.
Waste will be disposed of at suitably licenced waste facility, as approved by the Scottish Environment Protection Agency (SEPA) with a valid waste carrier licence. A waste transfer note (WTN) will be completed every time waste is removed from the site and retained for two years.

The following mitigation measures will be implemented:

Operators will have a duty of care to ensure the safe handling, storage, and transfer of waste. This includes maintaining proper documentation and ensuring that waste is only transferred to licensed carriers.
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.
Containment measures will be in place to prevent debris or pollutants from entering the surrounding environment.

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

Noise and vibration

Construction activities and working methods associated with the proposed works such as milling have the potential to cause noise, and vibration impacts through the use of machinery (e.g. planer) and construction vehicles. This potential disturbance will likely impact NSRs surrounding scheme extents, however, this is not anticipated to significantly increase noise levels from ambient levels.

TM, and associated congestion may also contribute to increased noise levels during the construction period.

Upon completion of the works, no adverse noise and vibration impacts are anticipated as the renewed road surface will not change the traffic speed or flows, and ambient noise levels are expected to return to pre-construction conditions. Surrounding NSRs will benefit from improved road surfacing as a result of the scheme and reduced noise levels.

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; for example:

Where reasonably practicable, quiet working methods will 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 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.
Operations will be sequenced to minimise simultaneous use of high-noise equipment, and a ‘soft start’ to works will be in place, whereby plant/machinery/vehicles are started sequentially as opposed to simultaneously.
Plant and machinery will be regularly maintained 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 will be undertaken before 23:00 where possible.

The following further mitigation measures related to noise and vibration will be in place:

Amey’s Noise and Vibration environmental briefing will be delivered to all site operatives before works start.
A letter drop will be delivered to residents within 300m to notify them of upcoming works, TM arrangements timings and duration.
Perth & Kinross Council Environmental Health Team has been contacted to notify of night-time programming.

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

No significant congestion issues are noted during the proposed construction hours; however, increased journey times will likely occur due to TM arrangements. These are not considered significant due to works being undertaken overnight, outwith peak traffic hours. Furthermore, no full road closures with diversion routes will be required to facilitate the works.

Residential and agricultural access points are located within the scheme extents, which may be impacted during construction and TM arrangements. However, the following specific measures will be in place to mitigate against significant impacts:

Access/egress will be maintained/granted throughout the construction period.
Construction lighting will be directional, to prevent illuminating surrounding properties to avoid a nuisance at night.
Perth & Kinross Council Environmental Health Team has been notified of the works.

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 through a letter drop to properties within 300m will be issued prior to commencement of the works, due to night-time programming and road restrictions;
Pre-construction notice of the works and journey planning via social media; and on approach to scheme extents.

Please see the Landscape and Visual Effects section above for an assessment of the visual impacts to visual receptors.

With best practice mitigation measures in place, no significant effects on population and human health are anticipated. 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 indirect impacts to the water environment from pollution events, such as the accidental spillage of fuels, oils, chemicals, and road planings and mobilisation of these in surface runoff and drainage systems.

No watercourses are located within 500m, therefore there will be no in-water works or abstraction or transfers of water from, or discharges to a waterbody. As such, the potential for a direct pollution incident within a waterbody is unlikely.

There will be no impact to the NVZ as the works are contained to the carriageway surface, ensuring no disturbance to surrounding land and no potential for increased nitrate levels.

The resurfacing works will not increase flood risk as they are limited to the existing impermeable carriageway surface, with no alteration to drainage infrastructure or surface water runoff patterns. No other post construction impacts are anticipated.

The following best practice and pollution prevention and control measures will be in place:

All operatives will be aware of SEPA’s Guidance for Pollution Prevention (GPP) documents.
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 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 at least 110% of the maximum volume of a single container.
Where refuelling on site is required, there will be designated refuelling areas, located more than 10m from surface water drainage systems, and within hard standing and bunds to prevent leaks or spills escaping.

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. However, given the nature of the scheme, the volume of materials required to be imported on site is not significant.

The following mitigation measures will be in place:

Where possible, materials and suppliers will be sourced locally to reduce GHG emissions associated with travel distance.
Where waste is to be disposed of, this will be disposed at a local waste management facility where possible.
Plant, machinery and vehicles will not be left idling when not in use.
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 is not identified at risk of pluvial or fluvial flooding. Works will, however, be programmed as far as is reasonably practicable to avoid periods of adverse weather or heavy rainfall.

The construction activities will be confined within the carriageway boundary, ensuring no increased risk or severity of major accidents or disasters impacting the environment.

Assessment cumulative effects

Perth & Kinross Planning Portal has not identified any extant planning applications surrounding the scheme extents that would result in any in-combination effects.

The Scottish Road Works Commissioner’s Interactive Map has not highlighted any works during the proposed timescale at the location of the works.

At present, Amey’s programme of works has not identified any other works on the A90 that will be undertaken in conjunction with the scheme. Any future 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.

During construction, activities associated with the works may have minor temporary disturbances such as changes to noise and vibration and air quality, and potential disturbance to local wildlife.

The scheme is not anticipated to have significant environmental effects having regard to its nature, scale and location. The residual impacts arising from the works can be appropriately mitigated and thus no cumulative or in-combination effects are anticipated.

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