Local Air Quality Management: Air Quality Management

Arun District Council: Review and Assessment Summary

Arun District Council has completed it's stage II and III air quality review and assessment. The stage I assessment was published in December 1998 and identified a number of pollutant sources within the district requiring further assessment.

The following roads were identified as being possible sources of nitrogen dioxide (NO2) and particulate matter (PM10):A27; A259; B2166; Aldwick Road, Barrack Lane and Hawthorn Road in Bognor Regis. Lafarge Redland Aggregates Ltd, a roadstone coating process authorised under the Local Authority Air Pollution Control (LAPC) regime was also identified as being a possible source of PM10 and sulphur dioxide (SO2). All sources of concern were subject to the minimum of a stage II assessment involving the use of models to predict future pollutant concentrations and subsequently assess whether the air quality objective for a specific pollutant would be met.

Road sources

Future pollutant concentrations along roads were estimated using the Design Manual for Roads and Bridges (DMRB), Vol 11, in accordance with guidance from the Department of the Environment, Transport and the Regions (DETR). The DMRB model uses existing traffic data to estimate vehicle emissions in future years.

Model predictions showed that all the road sections identified in stage I, with the exception of A27 Lyminster Road/Station Road/The Causeway section, were likely to meet the PM10 and NO2 air quality objectives in 2004 and 2005 respectively. The A27 Lyminster Road/Station Road/The Causeway section was predicted to meet the 2004 PM10 objective but to only equal the NO2 objective of 40 mg/m3. Therefore, it was decided to proceed to a stage III assessment involving the use of advanced modelling techniques for this section.

Advanced modelling was undertaken using the BREEZE ROADS model which incorporates emissions, traffic and meteorological data and provides estimates for both moving and idling vehicles. Predicted NO2 concentrations for 2005 were found to be less than the required air quality objective, so it was not necessary to declare an Air Quality Management Area (AQMA).

Industrial sources

The contribution of SO2 and PM10 from the Lafarge Redland stack was estimated using the GSS Environment Agency model, incorporating geographical and engineering data. When this value was added to the predicted background concentration, the total SO2 concentration for 2004/2005 was found to be below the air quality objectives set for SO2 Therefore no further assessment was needed. However, for PM10 the predicted total 2004 concentration was found to be within 5 mg/m3 of the annual mean air quality objective, so advanced modelling was undertaken to confirm whether the objective would be met by 2004.

The advanced AERMOD model results were of similar concentration to those from the GSS model and therefore it was decided not to proceed further.

To conclude, all areas identified as being of possible concern from the Stage I review and assessment were predicted to meet the necessary air quality objectives by the target year. Therefore, it was not necessary for this authority to declare any Air Quality Management Areas within the Arun District.

Click here for more details from the local authority website.

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