Tailored Living Solutions sought the expertise of REC Air Quality Consultant, Josh Jones, to assess air quality on a commercial and business development site at 131 Great Suffolk Street, Southwark, London.
Air Quality Case Study Background
The development is located within an Air Quality Management Area (AQMA), as declared by London Borough of Southwark due to exceeding the annual mean Air Quality Objective (AQO) for Nitrogen Dioxide and the 24 hour AQO for particulate matter with an aerodynamic diameter of less than 10µm (PM10).
There are therefore concerns that the proposals could expose future site users to elevated pollution levels. Additionally, the development has the potential to cause air quality impacts at sensitive receptor locations as a result of fugitice dust emissions associated with the construction phase. An Air Quality Assessment was therefore required to:
- Determine baseline conditions
- Consider potential exposure as a result of the development
- Provide consideration of potential effects as a result of the construction phases of the proposals
Air Quality Assessment Method
During the construction phase of the development there is the potential for air quality impacts as a result of fugitive dust emissions from the site. These were assessed qualitatively in accordance with the Greater London Authority methodology ‘Guidance on the Assessment of Dust from Demolition and Construction‘. Ensuring that the use of good practice control measures provides suitable mitigation for a development of this size and nature; reducing potential impacts to an acceptable level.
Dispersion modelling was used to quantify pollutant concentrations at the site and assess potential exposure of future users. The proposed development does not include any proposed use sensitive to long term pollutant concentrations, such as residential units. As a result, exposure to annual mean NO2 and PM10 exposure at the proposed development is not applicable (in accordance with the London Local Air Quality Management Technical Guidance LLAQM.TG (16). Subsequently, annual mean exposure across the proposed development has not been considered further in the context of pollutant exposure.
Hourly concentrations of NO2 and the predicted number of days with 24-hour mean PM10 concentrations greater than 50µg/m3 were modelled across the ground floor level and were subsequently verified using local monitoring results obtained from the LBoS. Exceedances of the 1-Hour mean AQO for NO2 were not predicted at any location across the development and the predicted number of days with PM10 concentrations greater than 50µg/m3 did not exceed the permitted number of 35 days across the development site.
Exposure across the ground floor of the development site was classified as APEC- -A. Since predicted concentrations across the ground floor were deemed acceptable, floor levels above this were not considered because pollutant concentrations are likely to be lower at elevated heights and increased distance from emission sources, such as roads.
The London Plan states that new developments must be considered Air Quality Neutral. Pollutant emissions associated with energy consumption within the development and traffic generated by the development were compared to relevant benchmarks. The results of the Air Quality Natural assessment concluded that the combined annual emissions are predicted to be below the combined benchmark level for both NOx and PM10. As such the proposed development is considered Air Quality Neutral.
Based on the assessment results the site is considered suitable for the proposed end use without the inclusion of mitigation measures and complies with the London Plan, the LBoS Local Plan and relevant legislation. Therefore suitable to pass planning application approval.