Description of main environmental impacts and proposed mitigation

Air quality

Given the rural setting, and limited scale and duration of the works, no significant impacts on air quality are anticipated. No dust-generating activities are proposed beyond minor disturbance associated with rock bag placement.

The presence of increased HGVs and construction plant presence may contribute to short-term exhaust emissions. TM measures will likely cause congestion and elevated traffic-related emissions during the works.

Please see the Road Drainage and the Water Environment for dust-related impacts on the water environment.

The following 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:

  • Drop heights from loading or handling equipment will be minimised;
  • Vehicles entering and leaving the work area will be covered 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 for the works.

Cultural heritage

No significant impacts on cultural heritage are anticipated as all designated assets lie outwith the scheme extents, physically separated by vegetation and infrastructure. Due to the localised nature of the works at the structure, and distance from heritage features recorded no impacts on the setting of the Listed Buildings is anticipated.

No non-designated features are located within 200m of the scheme extents, with works occurring within the existing footprint of the previous emergency works. The likelihood of disturbance to unknown archaeological remains is low.

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

Landscape and visual effects

The works are small-scale, temporary and confined to the existing footprint of previous similar works. As such, they will not alter the character of the landscape.

No static visual receptors are identified due to natural screening and physical distance from the structure. Transient receptors, such as A90 road users may experience short-term views of construction activity and plant, however, these effects will be brief, intermittent and not significant.

The following mitigation measures will be in place:

  • The site will be kept clean and tidy throughout all stages of the works, with appropriate storage of materials, equipment, plant and waste.
  • Works will avoid encroaching on land and areas where work is not required or not permitted, including for storage 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

The works are small-scale, temporary and confined to the existing footprint of previous similar works. As the structure spans the River South Esk SAC, and the works lie within a designated sensitive area, there is potential for short-term disturbance to the qualifying features, through in-channel working and sediment mobilisation.

Consultations have been undertaken with NatureScot and the Esk DSFB and impacts will be managed through pollution prevention measures, species protection plan and the required species licences.

An Ecological Clerk of Works (ECoW) will be on site during mobilisation and on an ad-hoc basis throughout the works to ensure compliance with working methodologies and licence conditions.

INNS have been identified within the general scheme area. In the absence of mitigation, works could risk spreading these species. An INNS Method Statement has been prepared detailing biosecurity measures and general construction safeguards to mitigate against the disturbance and spread of such species.

As works are taking place within the River South Esk SAC, under the Habitats Regulations Appraisal (HRA) process, a Stage 1 Screening report and Stage 2 Statement to Inform Appropriate Assessment (AA) will be undertaken in line with NatureScot consultation. No works will be undertaken without agreement from NatureScot and any change to the proposed working methods will be reviewed by them where required.

The following additional mitigation measures will be implemented:

  • The delivery of Amey’s Environmental Briefing on Invasive Plants will be to site operatives prior to the works commencing.
  • Biosecurity measures will be in place (e.g. ‘Check, Clean, Dry’ protocol prior and after any in river works).
  • 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.

Further mitigation measures in relation to pollution prevention and control measures are detailed within the Road Drainage and the Water Environment section below.

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

The works are small-scale and confined to previously disturbed areas, with no earthworks required.

The use of heavy plant and machinery on the riverbanks and access track has the potential to cause localised soil compaction and bank surface erosion. There is potential for pollution and contamination of soils either from accidental spills, or leaks of fuel from plant and machinery during construction.

The following mitigation measures will be implemented:

  • 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.
  • Plant and machinery will be parked and stored within the existing tracked area, to minimise soil compaction outwith these areas.

Further mitigation measures in relation to pollution prevention and control measures are detailed within the Road Drainage and the Water Environment section below.

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

Material use will be limited to new rock bags, which is not anticipated to significantly impact regional or national demand of material resources. Where feasible, the existing rock bags from the previous temporary works will be re-used on site, thus reducing the quantity of new materials.

Waste generation will be minimal and limited to damaged rock bags, and therefore, the volume of waste produced is not anticipated to be significant or contribute to landfill pressure.

Waste will be transferred to SEPA-authorised facilities by carriers with valid waste carrier registration. A waste transfer note (WTN) will be completed for removal of waste from site and retained for two years, in line with statutory Duty of Care requirements.

The following mitigation measures will be implemented:

  • Waste will be stored in suitable, covered containers, and segregated at the source where possible.
  • 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 used to minimise and prevent the disposal of unused materials.

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

The works are short-term, small-scale and will be undertaken during day-time hours only. Construction noise will be limited to plant and machinery movements, and that associated within rock bag placement and tree removal. No significant noise impacts are anticipated due to the distance from receptors, and high ambient road traffic levels. TM, and associated congestion may also contribute to increased noise levels during the construction period, however impacts identified are not lasting or significant.

No significant vibration impacts are expected as the works do not involve piling, breaking, or other vibration-heavy activities.

Mitigation measures follow Best Practicable Means as outlined in British Standard (BS) 5228:2009+A1:2014. The standard provides specific detail on suitable measures for noise control in respect to construction operations; for example:

  • 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.
  • 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.

Other mitigation measures should be implemented, including:

  • Drop heights will be minimised to minimise noise and vibration impacts.
  • Plant, vehicles and machinery will be switched off when not in use.

Population and human health

Temporary land take and way leave is required for access to the site from adjacent farmers’ fields. Amey have made initial enquiries for access, however, it is the Contractor’s responsibility to obtain access permissions, where required.

The works are small-scale, temporary and required for public safety to maintain the A90 as a key transport route. No residential, business or community land is within the scheme extents or will be impacted by the works. 

The underpass beneath the structure is currently largely inaccessible due to damage and fluctuating water levels, and therefore any additional restrictions during the emergency works will not have a significant impact on accessibility. The footway located over the structure, adjacent to the A90 is likely to be temporarily closed during the works, however, this will be managed through appropriate alternative measures and will be short-term.

TM on the A90 will likely be required during the works, however this will be short-term, with no significant effects on journey times, connectivity or access to services is anticipated.

No impacts on agricultural holdings or land use is anticipated, as access arrangements are via an established existing track within the northwest field.

The following mitigation measures will be implemented:

  • Where WCH routes are to be impacted by the works, alternative provisions or signposted alternative routes will be in place.
  • TM arrangements and programming will be advertised on approach to the site, and through an online media release.

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

The works have potential for short-term increases in sediment mobilisation and localised disturbance to the riverbed when repositioning and replacing rock bags. Additionally, there may be accidental pollution from spillage of fuels, which may have a direct impact on the water quality of the River South Esk.

Consultation with SEPA has been undertaken regarding the level of authorisation under the Environmental Authorisations (Scotland) Regulations 2018 (EASR) (as amended by the EASR Amendment Regulations 2025), confirming that the works are considered maintenance, and with compliance with mitigation measures and licensing advised by the Esk DSFB , no further authorisation under the regulations is required.

The following additional mitigation measures will be implemented:

  • Where required, refuelling will take place at least 10m from the River South Esk.
  • Any static plant or equipment used within 10m of the River South Esk will be positioned on a suitable drip tray with capacity for 110% of the fuel tank supplying the static plant of equipment.
  • Machinery used near River South Esk will be appropriately maintained to avoid oil leaks.
  • Washing of any machinery will take place at least 10m from the River South Esk and the washings will not enter the watercourse.
  • Appropriate silt mitigation will be implemented to prevent silt pollution of the watercourse during works, which includes:
  • Rock bags will be appropriately cleaned prior to being installed.
  • Rock bags will be installed in such a way that reduces drop heights and limits sediment disturbance.
  • Spill kits will be available and accessible on site at all times. There will be regular inspection and replenishment spill kits to ensure they are always ready for use.
  • All site operatives will be trained on how to use spill kits and respond to spills effectively.
  • Operatives will be made fully aware of the environmental risks associated with the scheme, including the environmental sensitivity and European designated of the River South Esk SAC.
  • All operatives will be aware of SEPA’s Guidance for Pollution Prevention (GPP) documents.
  • 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.
  • Please refer to the Biodiversity section above for more information.

With compliance with SEPA’s GPPs and the above mitigation measures, it is anticipated that any road drainage and the water environment effects associated with the proposed works are unlikely to be significant. Therefore, in accordance with DMRB Guidance document LA 113: Road drainage and the water environment no further assessment is required.

Climate

Construction activities may result in GHG emissions from vehicles, machinery, material use and production, and transportation. However, given the nature of the scheme, the volume of materials required to be imported on site is low, reducing the overall impact.

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.
  • Waste disposal will be directed to local licensed facilities.
  • 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

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

Vulnerability of the project to risks

The River South Esk is identified as having a high (10%) likelihood of fluvial flooding each year, with the surrounding land, including the northwest field where the access track is located, having a medium-to-high (0.5-10%) likelihood of pluvial flooding. Additionally, the works are located within a PVA, and the nature of the works further reinforces this assessment, with the works required to prevent any further scour, and damage at the structure and associated risk to the A90 carriageway from flood events.

Works will be programmed as far as is reasonably practicable to avoid periods of adverse weather or heavy rainfall and will ideally be undertaken during periods of lower water levels.

Assessment cumulative effects

The works are small-scale, temporary and confined to the existing footprint of previous repairs. Construction activities may result in minor, temporary disturbances such as increased in noise, however, these effects will be localised and effectively managed through mitigation. No significant environmental effects are anticipated.

Angus Council’s Planning Portal has not identified any extant planning permissions that would give rise to cumulative effects.

The Scottish Road Works Commissioner’s Interactive Map shows no planned roadworks on the A90 or surrounding network that would result in cumulative effects.

Amey’s current programme of works has also not identified any concurrent works within the North East area that will be undertaken in conjunction, or occurring in conflict with the proposed works.

Overall, no cumulative or in-combination effects are anticipated.