PPC PERMIT APPLICATIONS FOR STEWARTBY AND WHITTLESEY BRICKWORKS

View of the brickworks from the monitoring platform

Gair Consulting Ltd is providing support to SLR Consulting Ltd in the preparation of the PPC permit applications for Hanson Building Products’ brickworks at Stewartby in Bedfordshire and Saxon and Kings Dyke in Cambridgeshire. All three brickworks manufacture bricks from Lower Oxford Clay using the fletton process. The clay contains approximately 5% organic carbonaceous material which provides fuel for the firing process substantially reducing the need for supplementary fuels. However, the clay also contains high concentrations of sulphur and depending on the particular stage of the firing process can either result in elevated emissions of sulphur dioxide or reduced sulphur compounds such as hydrogen sulphide and mercaptans.

Emissions of sulphur dioxide are important given the potential health impacts associated with short term elevated concentrations of this pollutant. The reduced sulphur compounds are of interest due to the potential odour associated with these compounds.

Detailed air quality and odour assessments for each site were undertaken and included the following:

• analysis of continuous emissions monitoring systems data;
• the monitoring of odour chimney emissions using olfactometry;
• review of ambient air quality monitoring data;
• dispersion modelling of emissions from the brickworks chimneys using both AERMOD and ADMS;
• an air quality impact assessment for sulphur dioxide with an assessment of compliance with UK air quality objectives based on 15 minute, 1 hour and 24 hour concentrations;
• an odour nuisance assessment with comparison to Environment Agency offensiveness criteria; and
• a qualitative review of the effect of potential control measures to reduce emissions and for control measures identified as candidate Best Available Techniques (BAT).