Redmore Environmental was instructed to undertake an Ecological Air Quality Assessment in support of a planning application for a mixed use development on the 450-acre former Thoresby Colliery, Edwinstowe, Nottinghamshire. The proposal comprised construction of up to 800 dwellings, an employment site, a new country park and local centre, a primary school and a community hub.
Why Was an Ecological Air Quality Assessment Required?
The proposed development site is located close to a number of areas which are protected under National and European legislation due to their ecological importance. As the scheme was large and likely to generate a large amount of new traffic, concerns were raised that exhaust emissions associated with vehicles travelling to and from the site may have a negative impact on the designations. It was therefore necessary to quantify the change in pollution at the sensitive habitats.
How Does Pollution Affect Habitats?
Plants, as well as lichens, moss, bacteria and algae, can absorb material from their surroundings through their roots and surfaces. Pollutants deposited on the ground and released in the air can therefore be taken in by plants and influence their ability to survive and grow. Thresholds for these pollutants, called critical loads and critical levels, have therefore been defined. Where thresholds are exceeded there is a risk of harmful effects to the plant. These can result in changes in biology and lead to a shift in habitat composition. Plants are primary producers, serving as a source of energy for animals higher up in the food chain. This means that pollution can result in a loss of biodiversity and species richness, potentially degrading the features for which a site has been designated, impacting both flora and fauna alike.
Ecological Air Quality Assessment Methodology
The Multi-Agency Geographic Information for the Countryside (MAGIC) interactive map was utilised to identify the ecological designations which may be impacted by the development. This process identified the following designated sites for inclusion in the assessment:
- Birklands West and Ollerton Corner Site of Special Scientific Interest (SSSI)
- Birkland and Bilhaugh SSSI
- Birklands and Bilhaugh Special Area of Conservation (SAC)
A dispersion model was built which included two comparative scenarios, one forecasting future traffic conditions without the development in operation and another representing the same conditions but with the traffic associated with the scheme included. Predictions of concentrations and depositions rates were then made at individual locations within the designations for each scenario to allow a comparison to be made.
The change in pollutant concentration between the scenarios was calculated as a proportion of the relevant critical level or critical load to determine the level of impact resulting from the additional traffic. The assessment concluded that impacts at the designations were not significant, in accordance with the Institute of Air Quality Management criteria, as outlined in the ‘Use of Criteria for the Determination of an Insignificant Effect on Air Quality Impacts on Sensitive Habitats’. The report was submitted to Newark and Sherwood District Council as part of the planning application for the scheme.
Since the time of the assessment, the Institute of Air Quality Management have released a full guidance document ‘A guide to the assessment of air quality impacts on designated nature conservation sites‘. Current Ecological Air Quality Assessments are undertaken in accordance with this guidance, as well as the Environment Agency and DEFRA ‘Air Emissions Assessment risk assessment for you Environmental Permit‘ guidance.
In-Combination Assessment
Following submission of the planning application, a consultation response was received from Natural England indicating concerns regarding potential cumulative impacts on the ecological designations as a result of pollution from existing or consented plants and farms in the vicinity of the site. An In-Combination Assessment of potential sources within 5km of the development was therefore undertaken by incorporating the additional emissions into the dispersion model. The results indicated that pollutant concentrations at the SSSI and SAC were below the relevant thresholds and therefore impacts were considered to be not significant. The report was submitted to Newark and Sherwood District Council for Natural England review.
Air Quality Monitoring Strategy
Planning consent for the development was granted by Newark and Sherwood District Council, subject to a number of conditions. These included a requirement to prepare an Air Quality Monitoring Strategy to verify the assessment outputs. This was therefore produced to allow review of air quality conditions at the designated sites both before completion and up to 10 years from first occupancy and operation of the proposals. The condition was fully discharged in August 2019.
Do You Need an Ecological Air Quality Assessment?
Assessment of impacts at sites of natural importance is a complex process which draws on multiple sources of information and guidance. The team at Redmore Environmental have prepared ecological assessments for a range of sectors including energy, residential and commercial, waste and manufacturing, and have even developed novel assessment approaches for complex sites. If you require Air Quality Consultancy services for your development, please get in touch to discuss how we can help you achieve consent.