What we do

Air Quality

Public health issues surrounding air quality have been on the environmental agenda for many years. Air pollution is widely evidenced to have a direct, negative impact upon health contributing to heart disease, strokes, lung disease and cancer.

However, an ever-growing population demands an infrastructure that accommodates all aspects of modern living. The need for development in some areas of the UK is in direct conflict with the need to protect human health and the environment and maintain clean air. Consequently, planning or permitting consent may be refused on the basis of air quality considerations and a thorough Air Quality Assessment could prove pivotal in determining the success or failure of your project.

IDOM Merebrook can provide a comprehensive range of air quality services and assessments that are frequently required as part of planning and environmental permit applications or formal Environmental Impact Assessments.

Further details of the types of works we currently offer are provided below, however, our flexible and innovative approach allows us to continually develop our services to meet new and challenging client needs.

Our services include:
• Air Quality Assessments
• Atmospheric Dispersion Modelling
• Stack Height Assessments
• BREEAM Indoor Air Quality Plans
• Odour Assessments
• Assessment of Air Quality Impacts on Sensitive Ecological Sites
• Environmental Permitting
• Passive and real-time dust/PM10 monitoring
• Environmental Statement chapters
• Expert Witness

Air Quality

Air Quality Assessment

Air Quality Assessment

Air quality is a material consideration within the planning regime and Air Quality Assessments are routinely required to demonstrate that a site is suitable for its intended use and will not result in unacceptable impacts on human health or sensitive habitats during either construction or operation.

The scope of an Air Quality Assessment can vary considerably depending on the type of project, geographical location and baseline conditions at the site. At IDOM Merebrook we utilise our extensive knowledge and experience to identify the most appropriate and cost-effective scope for your project. This can range from a simple, qualitative assessment to detailed assessment of emissions including dispersion modelling of traffic and energy centre emissions. For developments in Greater London, our assessments also include an Air Quality Neutral assessment as standard.

Where timescales allow, we liaise with the Local Planning Authority to agree the scope of assessment and any dispersion modelling inputs in advance. By doing this we aim to streamline consultee feedback to avoid delays in determination of the application.

Our team have prepared assessments for projects across the UK including residential schemes, industrial sites, district heating schemes, hospitals, schools and large-scale mixed-use developments.

We work closely with transport, energy and planning consultants to ensure that the potential air quality impacts of a scheme are fully understood and assessed and to ensure consistency across the application documents.

Our Air Quality Assessments include the following where relevant:
• Air Quality Neutral Assessments
• Air Quality Positive Statements
• Air Quality Mitigation Strategies
• Damage Cost Calculations

Atmospheric Dispersion Modelling

IDOM Merebrook utilises the most advanced dispersion modelling software from the ADMS family of models to simulate the three-dimensional dispersion of pollutants released to atmosphere.

We work closely with design engineers, operators and transport consultants as appropriate to ensure that the inputs for a dispersion modelling exercise are obtained in a timely manner to minimise delays.

Our team uses dispersion modelling to support all aspects of air quality and odour assessment associated with planning and permit applications including:
• Stack height assessments to determine appropriate discharge height for combustion plant
• Air emissions risk assessment to accompany environmental permit applications
• The increase in road traffic emissions associated with new development
• Odour emissions from existing or proposed operations

Case studies demonstrating our dispersion modelling experience include Carlsberg Brewery in Northampton, Encirc Glass, Cheshire, Royal Sussex University Hospital, Brighton and the Kingsgate building in Westminster.

Odour Assessments

Odour Assessments

Odour is a material consideration in the planning system which has the task of guiding development to the most appropriate locations.
It is essential that where new development (particularly residential development) is proposed close to an existing odour source (sewage works, farmland, industrial process), the potential for odour nuisance is carefully evaluated.

The degree of odour impact is determined by the parameters collectively known as the FIDOL factors (Frequency, Intensity, Duration, Offensiveness and Location). Human appraisal of the FIDOL factors and social and psychological factors determines whether an odour has an adverse odour impact and an objectionable effect.

Odour is a complex issue due to its subjective nature and the variation in sensitivity of individuals within the population. The process of odour assessment therefore requires a high degree of professional judgement.

Our team use their expert knowledge and experience to select the most appropriate combination of assessment tools in order to provide a bespoke approach for each project. Depending upon whether the issue is the operation of a proposed or existing odorous process, or the introduction of odour-sensitive development close to an existing odour source, the assessment methodology may include:
• Dispersion modelling
• Field olfactometry surveys
• Odour sampling and analysis
• Qualitative risk assessment (using the source-pathway-receptor concept)
• Complaints analysis
• Commercial kitchen risk assessment

Assessment of Air Quality Impacts on Sensitive Ecological Sites

In Britain, the main threat to nature conservation sites in terms of air pollution is as a result of elevated ambient concentrations of oxides of nitrogen (NOx) and ammonia (NH3).

As well as resulting in direct toxic effects on vegetation, both NOx and NH3 contribute to nitrogen deposition. Nitrogen deposition can lead to acidification of soils and loss of species diversity, as well as increasing the risk of damage from frost, drought and pests.

Road transport emissions are a major contributor to air pollution problems at protected sites, particularly where major roads run through, or in close proximity to threatened habitats.

Heathland habitats, including heather, lichens and mosses, are particularly sensitive to air pollution. Elevated levels of nitrogen encourage the growth of grasses and bracken which competitively exclude the heath species over time due to shading or competition for other limited resources.

Our team of experts has extensive experience of working alongside ecologists to robustly assess the impacts of both individual developments and Local Plans on sites of ecological importance. This ranges from dispersion modelling to inform Appropriate Assessment as part of the Habitats Regulations Assessment process to the production of stand-alone Nitrogen Deposition Studies.

Case Studies




sensitive habitats