A developer's guide to planning for air quality in Dorset - Part 1

Introduction

Dorset is a county located in the South West region of England. It is known for its stunning natural landscapes, picturesque coastline, and rich historical and cultural heritage. The county’s county town is Dorchester, a historic market town. Other significant towns in Dorset include Bournemouth, Poole, Weymouth, and Wimborne Minster.

The county is famous for its natural beauty, filled with ecological sites including woodlands and nature reserves, and including the Jurassic Coast, a UNESCO World Heritage Site.

Agriculture has traditionally been an important part of Dorset’s economy, with dairy farming and arable agriculture being prominent.

The county is one of the few English counties without a motorway. Instead, the county relies on two major roads, the A35 and A31, for its road network. The A35 originates in Bournemouth and serves as the sole direct A road linking Dorset to the West, while the A31 extends eastward, leading travellers out of Dorset and into Hampshire.

Developers play a pivotal role in shaping our urban landscapes, and with this role comes the responsibility of understanding and adhering to local guidance on air quality.

Do I need to carry out an air quality assessment for my development in Dorset?

Local guidelines can vary from one authority to another. Firstly, developers need to understand the implications of local air quality regulations and standards on their project.

This article aims to help developers recognise where they should take air quality into account, and any potential constraints their proposed development might face, such as Air Quality Management Area’s (AQMA). Specifically, it addresses scenarios in which an air quality assessment is required, ensuring that project aligns with local air quality policy and secure planning approval.

Additional factors that may require consideration include the scale and nature of the development, ad national policy, guidance and air quality objectives. However, this provides a good initial understanding of local air quality requirements in Dorset.

Air quality hotspots in Dorset

There are two areas in Dorset Council’s administrative area which are considered to have high air quality concentrations, and therefore will endure greater scrutiny from the local authority over the potential impacts of proposed developments. These areas are declared Air Quality Management Areas (AQMAs). Further information on an AQMA can be found in my blog post linked here.

The two AQMA’s are:

· Chideock

· Dorchester High East Street

Caution should be exercised when considering residential or sensitive developments in the vicinity of AQMA’s. If a proposed development introduces additional traffic to the area, the council will likely request assurances that this won't compromise the timeframe to bring pollution levels in line with UK air quality standards, or compromise the Air Quality Action Plan.

Air quality planning guidance in Dorset

Dorset County Council (DCC) are currently working on a new Dorset Council Local Plan to be adopted in May 2026. The adopted local plans for the former council areas are in place until the new local plan is adopted. These include:

· West Dorset, Weymouth and Portland

· Purbeck

· North Dorset

· East Dorset and Christchurch

· Swanage

Bournemouth, Christchurch and Poole (BCP) are also situated in Dorset. These three councils will be amalgamated to form BCP Council. Air quality planning guidance for BCP will be discussed in the next blog post.

Air quality planning guidance in West Dorset, Weymouth and Portland

West Dorset and Weymouth & Portland adopted a joint local plan in 2015, that forms the main basis for making decisions on planning applications and development in the area until 2031.

This administrative area is rich in ecological designated sites, therefore the local plan requires the cumulative and indirect impacts of development to be taken into account when assessing potential harm to habitats and ecological sites of national or local importance.

The councils may ask for an air quality assessment if there is reason to believe that the development would give rise to a significant change in air quality (either individually or cumulatively with other planned development). Significant change in air quality could be down to industrial processes (including the use of biomass boilers and combined heat and power plants) or through local traffic generation.

Both of the Dorset Councils AQMAs are situated in West Dorset and Weymouth & Portland’s administrative area.

Chideock AQMA is situated within this administrative boundary and therefore particular caution should be exercised when planning a development in or close to this area.

In Dorchester, elevated pollution levels primarily occur along High East Street. This has resulted in an AQMA encompassing this street and surrounding area. Therefore, proposed developments in or near this area will require careful design and planning when considering air quality.

Developers must consider potential air quality effects when designing a development located in or near these AQMAs. Even if a development is not planned for the vicinity of these roads, it may still increase traffic on these routes, necessitating an assessment of its impact on air quality.

Air quality planning guidance in Purbeck

Purbecks Local Plan was adopted in 2012 and it is used to guide new development and determine planning applications up to 2027.

The main concern featured in Purbecks Local Plan is the Dorset Heathlands SAC/SPA, located across Purbeck. Should a development site be proposed in proximity to this European habitat and wildlife site, assurance that new development will not have an adverse impact on this protected site, in the form of assessment and mitigation measures, will be required.

Air quality planning guidance in North Dorset

The North Dorset Local Plan was adopted in 2016. There are no AQMA’s within this area. The local plan does not have a specific policy relating to air quality, however it refers to national guidance, in that it requires that proper consideration be given to the effect of local environmental quality (such as noise and air quality) on the health and well-being of any residents as a result of new development.

Air quality planning guidance in East Dorset and Christchurch

The East Dorset and Christchurch Joint Core Strategy, adopted in 2014, highlights the developmental land located within the Airport site, earmarked for the North West and North East business parks. Approximately 60 hectares of employment land remains for development.

Increases in road and air traffic have implications for air quality which have potentially harmful impacts upon sensitive environmental habitats which lie within and adjoining the site. An increase in traffic on National Park roads, associated with new development, will need to be considered.

To facilitate the growth of the airport and business parks, measures to mitigate air quality impacts are essential. These mitigation measures hinge on understanding the impact on sensitive receptors, a determination that can be achieved through an air quality assessment.

Air quality tips for developers to be aware of:

• Dorset county is currently under a number of mergers. There will be two local plans covering the whole of the county in future years; Dorset Council and BCP Council. This will likely result in changes or introductions of air quality policies

• Where the AQMAs / air quality hot spots are located

• If sensitive receptors are located in proximity to the site, these can include human receptors and ecological receptors

• The policy referring to air quality in the relevant local plan

• There are stricter air quality objectives following the recent update to the Environment Act

Air quality guidance for Devon

Air quality guidance and policies for district authorities covering Devon can be found in the below blog posts;

• A developers guide to planning for air quality in Devon – Part 1

• A developers guide to planning for air quality in Devon – Part 2

How can we help?

Seeking expert advice will help provide an early understanding of the feasibility of your development site and any potential constraints involved, before committing to a development.

Understanding local guidance on air quality is a fundamental responsibility for developers. This task can be designated to an expert air quality consultant, already familiar with local policy and guidance.

Exe Valley Environmental can help navigate you through the planning process and understanding the air quality consultancy services that may be necessary for your development. We will guide you through each stage, from early design and pre-planning advice, to supporting planning applications and discharging air quality conditions. If you’re unsure about the assessments your project might need in terms of air quality, drop me a call/message or a note via the contact form, for some non-committal advice.

kerrie@evenvironmental.co.uk

07805951564