REC’s Air Quality Consultants were commissioned to undertake Air Quality Assessments in support of the planning applications for the development of fifteen residential sites across Southwark, London. The developments ranged in size from 5 to 100 units and are part of Southwark’s plan to build 11,000 new council homes by 2043.
Air Quality Concerns
Each of the fifteen sites were located within an Air Quality Management Area (AQMA) declared by Southwark Council for exceedences of the Air Quality Objectives (AQO) for nitrogen dioxide (NO2) and particulate matter with an aerodynamic diameter of less than 10mm (PM10). As such, there was concern that elevated pollutant concentrations across the sites may result in the exposure of future users to poor air quality. Additionally, the developments had the potential to cause impacts as sensitive locations as a result of fugitive dust emissions during the construction phase and road vehicle exhaust emissions during the operational phase.
Air Quality Assessment Outcome
A screening assessment was undertaken for each site using the Design Manual for Roads and Bridges (DMRB) guidance to determine the potential for impacts as a result of traffic generated by each development. Due to the small scale of all fifteen sites, it was determined that none of the proposals would meet the criteria required for significant impacts. In order to efficiently model pollution concentrations across the fifteen individual locations, six dispersion models were completed using the software package ADMS Roads, which in total covered almost the entire borough of Southwark. Each of the sites presented a different challenging aspect, such as modelling a complex road network including the Rotherhithe Tunnel at Albion Street or determining appropriate mitigation in areas of high levels of pollution along Old Kent Road.
The results of the dispersion modelling indicated that three of the sites required mitigation to protect future users from poor air quality. Options suggested included mechanical ventilation with NOx filtration and the installation of windows with a high specification of tightness. The remaining twelve developments were considered suitable for residential use in regards to air quality with no mitigation measures required.
Based on the assessment results, air quality was not considered to be a constraint to the planning applications, subject to the inclusion of mitigation measures for three of the developments.