Brentwood Borough Council Local Air Quality Management – Progress Report April 2005 Report written by: Ken Nicholson (Nicholson Environmental) For Essex County Council Waste, Recycling and Environment Environmental Strategy County Hall Chelmsford Essex CM1 1QH On behalf of: Richard Farr Brentwood Borough Council Council Offices Ingrave Road Brentwood Essex CM15 8AY This report has been compiled as part of the Essex Air Quality Consortium Monitoring Network. Brentwood Borough Council LAQM Progress Report 2005 Contents 1. Introduction..................................................................................................3 1.1 Background.......................................................................................3 1.2 Outcome of previous Review and Assessments...............................3 2. Monitoring data............................................................................................4 2.1 Atmospheric concentration measurements.......................................4 2.2 Nitrogen dioxide (NO2)......................................................................5 3. Emission sources ........................................................................................9 4. New developments and planning in Brentwood.........................................10 5. Local Transport Plan..................................................................................10 6. Summary and Conclusions........................................................................10 APPENDIX 1 Summary of Reporting Schedule...............................................11 APPENDIX 2 Air Quality Management Areas..................................................13 Tables Table 2.1 Monitoring results from automatic site at Brentwood ..........................5 Table 2.2 Nitrogen dioxide diffusion tube monitoring results...............................8 Figures Figure 2.1 Location of nitrogen dioxide diffusion tube sites in Brentwood ..........6 2 Brentwood Borough Council LAQM Progress Report 2005 1. Introduction 1.1 Background This Progress Report is a requirement of the Environment Act 1995, Part IV, which places a duty on local authorities to review and assess air quality within their area periodically. The report is provided on an annual basis, following the Updating and Screening Assessment (USA) that was carried out in 2003, as part of the second round of Review and Assessment. The schedule for reporting is shown in Appendix 1. The objective of the Progress Reports is to provide continuity in the Local Air Quality Management (LAQM) process, by identifying any potential changes in air quality that might occur between the scheduled Review and Assessments which are due to be undertaken on a three-yearly basis. They are intended also to help local authorities by providing a means for communicating air quality information, increasing the effectiveness of the monitoring effort being carried out and providing a cost effective solution to address future monitoring needs. This Progress Report has been compiled with reference to the Progress Report Guidance (LAQM.PRG (03)) which was published by Defra in 2003. It presents information that has been collated since the production of the USA report, including air quality monitoring data, information about emission sources and any proposed developments, which have the potential to affect air quality in the Borough. 1.2 Outcome of previous Review and Assessments Brentwood Borough Council undertook their First Round of review and assessment, including Stages 1, 2 and 3 reports, during the period 1998 and 2000, following the introduction of the National Air Quality Strategy and Air Quality Regulations. The First Round assessments (Stages 1, 2 and 3) concluded that road traffic emissions from vehicles on the M25, A12 and A127 were the main concerns related to local air quality. However, it was concluded that it was not necessary to declare any Air Quality Management Areas (AQMAs) for any pollutant in the Borough of Brentwood. The USA reconsidered the seven health based air quality objectives and was completed in October 2003. The USA concluded that a detailed assessment would be required for road traffic emissions from the A12 and the following Junctions: · M25/ A12; · A128/ A1023 Wilson’s Corner; and · High Street/ Kings Road. 3 Brentwood Borough Council LAQM Progress Report 2005 In addition, the USA concluded that the provisional annual PM10 objective for 2010 was predicted to be exceeded at all busy roads and junctions assessed, due to the high modelled background PM10 for 2010. Consequently, it was recommended that this would be likely to require further consideration in future air quality assessments. The USA recommended also that Brentwood Borough Council continued with the monitoring programme for NO2. The Detailed Assessment was completed in April 2004 and considered the NO2 annual mean objective (40 mg/ m3) through dispersion modelling using the ADMS-Roads model. Verification of the model was undertaken using 2003 monitoring data, although due to prevailing meteorological conditions, this was a poor year for air quality and yielded higher monitoring results for NO2 than in previous years. The results of the detailed modelling showed that there were likely to be exceedences of the NO2 annual mean objective identified at the nearest receptors to A12, and the A12/ M25 and A128/ A1023 Wilson’s Corner Junctions. A marginal exceedence of the objective (40.5 ìg/ m3) was predicted also for 2005 at the nearest receptor to the High Street/ Kings Road Junction. As a consequence of the Detailed Assessment, it was recommended that Brentwood Borough Council considered declaring Air Quality Management Areas (AQMAs) on the basis of the potential exceedences that were identified. Brentwood Borough Council has since designated 7 AQMAs. These AQMAs are shown in Appendix 2. 2. Monitoring data 2.1 Atmospheric concentration measurements Brentwood Borough Council measures air quality in the Borough using an automatic air quality monitoring station situated at the Council Offices in Brentwood. Continuous NO2 concentrations are measured using a chemiluminescent analyser. The stations are calibrated in-house on a fortnightly basis according to the manufacturer’s instructions and the data are regularly downloaded and ratified. The manufacturer of the equipment, services the station on a six monthly routine basis. As well as the automatic monitoring stations, diffusion tubes are used to measure NO2 in the Brentwood Borough. Up until March 2004, NO2 diffusion tubes were exposed at 53 locations. However since then, the number of sites has been reduced to 39. The diffusion tubes used by Brentwood Borough Council are supplied and analysed by Harwell Scientific Services. A preparation method using 50% TEA (triethanolamine) in water is adopted. The correction factor for 2004 (to allow for bias) has been calculated as the mean of four parallel measurements 4 Brentwood Borough Council LAQM Progress Report 2005 (including diffusion tubes and automatic analysers). The results of these measurements are given on the University of the West of England website: (http://www.uwe.ac.uk/aqm/review/diffusiontube280205.xls). The mean correction factor for 2004 is 0.89 and the reported values (for 2004) have been corrected using this factor. The locations of the measurement sites are shown in Figure 2.1. The results from the automatic monitoring station are summarised in Table 2.1 and the results of the diffusion tube analysis are given in Table 2.3. Table 2.1 Monitoring results from automatic site at Brentwood Pollutant Statistic Year 2000 2001 2002 2003 2004 2005 Nitrogen dioxide Annual mean concentration 30.4 34.9 - 35.0 31.4 30.6 3 (NO2) (mg/ m ) Max 1 hour mean concentration (mg/ m3) 123.6 Exceedences of hourly objective 0 (200 mg/ m3) Data capture (%) 94.3 Notes: the 2005 annual mean value for NO2 is predicted from 2004 measurements and assuming a decrease in exhaust emissions detailed by Defra in LAQM.TG (03). 2.2 Nitrogen dioxide (NO2) The annual mean NO2 concentration measured at the automatic station in 2004 (see Table 2.1) was 31.4 µg/ m3. This is well below the objective limit for the annual mean (40 µg/ m3) and is consistent with measurements made in previous years. There is no significant trend in the annual mean concentration since measurements commenced in 2000. There were no exceedences of the hourly mean objective (200 µg/ m3) measured in 2004. The diffusion tube monitoring results show that there are current exceedences of the NO2 annual mean objective for 2005 at a number of sites in Brentwood (see Table 2.2). However, the potential exceedences at these sites have been addressed by the designation of the Air Quality Management Areas in Brentwood. Future measurements should be scrutinised from this site. Predicted annual mean concentrations of nitrogen dioxide in 2005 are marginally less than those measured in 2004. 5 Brentwood Borough Council LAQM Progress Report 2005 Figure 2.1 Location of nitrogen dioxide diffusion tube sites in Brentwood Reproduced by permission of Ordnance Survey® on behalf of the Controller of Her Majesty's Stationery Office. ©Crown Copyright. Licence number LA100019602 No. x y Location BRW 1 559861 193617 Council Offices control next to existing Nox monitor. BRW 2 556890 192435 73 Brook Street on rear downpipe Telegraph pole at end of Brook Street facing Brook Street BRW 3 556887 192412 roundabout BRW 4 556958 192285 The Poplars, Brook Street, rear downpipe facing M25 BRW