Air quality and the planning process

Tom Graham, a barrister specialising in town and country planning, environmental law and highway law examines how air quality can be raised by interested parties in connection with applications for planning permission.

In essence the planning process devolves into the following:
• Legislation
• National Planning Policies
• Local Planning Policies
• Development control (i.e. individual planning applications).
It is fair to say that air pollution is a material consideration at all of these levels. The current starting point is the Environment Act 202.

The Environment Act 2021 and air quality
Not surprisingly, the 2021 Act contains a raft of provisions which go to air quality. It is necessary to determine how they relate to day-to-day development control; bearing in mind, in particular, the objective of seeking to avoid the duplication of regulatory controls.

So far as air quality is concerned, the provisions of the Act create a mix of statutory discretions and mandatory statutory duties and it is important to distinguish them.

The Secretary of State may set ‘long-term targets’ in respect of any matter which relates to the “natural environment”, or people’s enjoyment of the natural environment. The use of the word ‘may’ makes this a statutory discretion, and not a duty; however, the Act then goes on to provide that the Secretary of State must exercise the power so as to set a long-term target in respect of at least one matter within each ‘priority area’, and this a statutory duty.

The ‘priority areas’ are air quality, water, biodiversity, resource efficiency and waste reduction. The phrase ‘air quality’ is not defined and so need not be limited to particulate matter.

The achievement of national air quality standards might be relevant to individual planning applications.

The Environment Act 1995
Moving from national to district, the Environment Act 1995 required local authorities to assess and manage the quality of the air in their areas. Where specified standards and objectives are not being met, they are required to declare Air Quality Management Areas and then prepare action plans. The Secretary of State has produced the National Air Quality Strategy, which specifies the standards and objectives that local authorities need to achieve. The Act is intended to strengthen these duties by giving greater clarity to the requirements of action plans thus enabling greater collaboration between all tiers of government, as well as with relevant public authorities, in the creation and delivery of those plans. It also requires the Secretary of State to regularly review the National Air Quality Strategy.

The National Planning Policy Framework states that planning policies and decisions should sustain and contribute towards compliance with relevant limit values or national objectives for pollutants, taking into account the presence of Air Quality Management Areas and Clean Air Zones and that planning decisions should ensure that any new development in Air Quality Management Areas and Clean Air Zones is consistent with the local air quality action plan.

Thus, the National Planning Policy Framework places these air quality strategies on the table when making planning decisions.

Development plans and air quality
The National Planning Policy Framework argues that opportunities to improve air quality or mitigate impacts should, so far as possible should be considered at the local plan-making stage, to ensure a strategic approach and limit the need for issues to be reconsidered when determining individual applications.

The National Planning Policy Framework states:
186. Planning policies and decisions should sustain and contribute towards compliance with relevant limit values or national objectives for pollutants, taking into account the presence of Air Quality Management Areas and Clean Air Zones, and the cumulative impacts from individual sites in local areas. Opportunities to improve air quality or mitigate impacts should be identified, such as through traffic and travel management, and green infrastructure provision and enhancement. 

Development control and air pollution
Turning to the assessment and determination of individual planning applications by local planning authorities, paragraph 186 of the National Planning Policy Framework goes on to say:
186. . . . Planning decisions should ensure that any new development in Air Quality Management Areas and Clean Air Zones is consistent with the local air quality action plan.

The National Planning Practice Guidance website also contains advice on this topic:
When could air quality considerations be relevant to the development management process?
Whether air quality is relevant to a planning decision will depend on the proposed development and its location. Concerns could arise if the development is likely to have an adverse effect on air quality in areas where it is already known to be poor, particularly if it could affect the implementation of air quality strategies and action plans and/or breach legal obligations (including those relating to the conservation of habitats and species). Air quality may also be a material consideration if the proposed development would be particularly sensitive to poor air quality in its vicinity.

What specific issues may need to be considered when assessing air quality impacts?

Considerations that may be relevant to determining a planning application include whether the development would:
• Lead to changes (including any potential reductions) in vehicle-related emissions in the immediate vicinity of the proposed development or further afield. This could be through the provision of electric vehicle charging infrastructure; altering the level of traffic congestion; significantly changing traffic volumes, vehicle speeds or both; or significantly altering the traffic composition on local roads. Other matters to consider include whether the proposal involves the development of a bus station, coach or lorry park; could add to turnover in a large car park; or involve construction sites that would generate large Heavy Goods Vehicle flows over a period of a year or more;
• Introduce new point sources of air pollution. This could include furnaces which require prior notification to local authorities; biomass boilers or biomass-fuelled Combined Heat and Power plant; centralised boilers or plant burning other fuels within or close to an air quality management area or introduce relevant combustion within a Smoke Control Area; or extraction systems (including chimneys) which require approval or permits under pollution control legislation; . . . .
[Paragraph: 006 Reference ID: 32-006-20191101 – Revision date: 01 11 2019]

Air quality is not, necessarily, a consideration confined to major new developments. New drive-through restaurants can become localised hotspots for air pollution. A change in traffic signalling arrangements at a road junction could lead to longer queues of traffic with idling engines.

In both examples, the dangers are not simply limited to those in nearby properties. People waiting in cars are not protected because studies have shown that pollutants can accumulate within a car, often to higher levels than outside it.

The National Planning Practice Guidance goes on to add to its list of considerations, whether the development would:
• Expose people to harmful concentrations of air pollutants, including dust. This could be by building new homes, schools, workplaces or other development in places with poor air quality;
• Give rise to potentially unacceptable impacts (such as dust) during construction for nearby sensitive locations;
• Have a potential adverse effect on biodiversity, especially where it would affect sites designated for their biodiversity value.
[Paragraph: 006 Reference ID: 32-006-20191101 – Revision date: 01 11 2019]

The final bullet-point flags up that air pollution can have a deleterious effect on ecology.

It is, therefore, clear that matters of air pollution can, properly, be raised by interested parties in connection with applications for planning permission.