Local Air Quality Management Ref: CS/AQ/AGGX0057/SA/2154
DOCUMENT INFORMATION AND CONTROL SHEET Client Brentwood Borough Council Council Offices Ingrave Road Brentwood Essex CM15 8AY Project Manager Tel: Fax: Richard Farr 01277 261111 Environmental Consultant Casella Stanger Great Guildford House 30 Great Guildford Street London SE1 0ES Project Manager Tel: Fax: Sharon Atkins 0207 9026167 0207 9026149 Project Team Giuliano Gianforte Richard Maggs Sharon Atkins Principal Author Sharon Atkins Document Status and Approval Schedule Status Description Prepared by: Sharon Atkins Senior Consultant Reviewed by: Richard Maggs Principal Consultant Draft Report Issued to client by email Signed/Dated Signed/Dated Final Report Issued to client by email and post Ref: CS/AQ/AGGX0057/SA/2154
CONTENTS Page Executive Summary 1 1. Introduction 2 1.1 Project Background 2 1.2 Summary of Review and Assessment 2 1.3 The First Round of Review and Assessment 2 1.4 The Second Round of Review and Assessment 2 1.5 Scope and Methodology of the Detailed Assessment 3 2. Baseline Information 4 2.1 Traffic Data 4 2.2 Air Quality Monitoring Data 6 2.2.1 Local Monitoring Data 6 2.3 Background Concentrations 9 3. Dispersion Modelling Methodology 10 3.1 Model Verification and Adjustment 11 3.1.1 NO X /NO 2 11 4. Results 12 4.1 A12 Brentwood Bypass Assessment Areas 12 4.2 Brentwood High Street Assessment Areas 13 5. Conclusions and Recommendations 14 6. Appendix 1 Monitoring Trends 15 7. Appendix 2 Verification of NO x /NO 2 16 8. Appendix 3 Figures 24 Ref: CS/AQ/AGGX0057/SA/2154 i
EXECUTIVE SUMMARY Part IV of the Environment Act 1995 places a statutory duty on local authorities to review and assess the air quality within their area and take account of Government Guidance when undertaking such work. This Detailed Assessment is a requirement of the second round of review and assessment for local authorities that have identified areas for further assessment in their previously submitted Updating and Screening Assessment (USA). The Detailed Assessment has been undertaken in accordance with the Technical Guidance LAQM.TG (03). Between 1998 and 2000, Brentwood Borough Council undertook its first round of review and assessment of air quality. The first round assessments (Stages 1, 2 and 3) concluded that it was road traffic emissions from vehicles on the M25, A12 and A127 that were the main issues with respect to local air quality, but that it was not necessary to declare an Air Quality Management Area (AQMA). The first phase of the second round of review and assessment, the USA, was completed in September 2003 and this provided an update with respect to air quality issues within Brentwood Borough Council. The USA concluded that a detailed assessment was required for nitrogen dioxide (NO 2 ) due to road traffic emissions from the A12 and three heavily trafficked junctions: A12/M25 Junction, A128/A1023 Wilson s Corner Junction and High Street/Kings Road Junction. The Department for Environment, Food and Rural Affairs (DEFRA) has accepted the USA conclusions. This Detailed Assessment considers the NO 2 annual mean objective, through dispersion modelling using the ADMS-Roads model. Verification of the model has been undertaken using 2003 monitoring data, which due to prevailing meteorological conditions, was a poor year for air quality and yielded higher monitoring results for NO 2 than in previous year s monitored (See Appendix 1 for monitoring trends). Results of the detailed modelling show that there are exceedences of the NO 2 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 (40.5ìg/m 3 ) is also predicted in 2005 at the nearest receptor to the High Street/Kings Road Junction. As the model is precautionary, it is recommended that NO 2 monitoring be undertaken at this receptor location to provide confirmation of compliance with the Objective. It is also recommended that NO 2 monitoring be undertaken at sensitive receptors with the highest predicted concentrations in the other assessment areas where exceedences are predicted to confirm model predictions and provide additional information in support of further assessment work. It is recommended that Brentwood Borough Council consider declaring Air Quality Management Areas (AQMAs) on the basis of the potential exceedences as highlighted in this, where exposure criteria are fulfilled. Ref: CS/AQ/AGGX0057/SA/2154 Page 1
1. INTRODUCTION 1.1 Project Background Part IV of the Environment Act, 1995, places a statutory duty on local authorities to periodically review and assess the air quality within their area. The Detailed Assessment is a requirement of the second round of review and assessment for local authorities that have identified areas where there is a risk of exceedence of an air quality objective within their Updating and Screening Assessment (USA). This is due to be completed by the end of. Casella Stanger was commissioned by Brentwood Borough Council to undertake their Detailed Assessment based on the information received by the local authority and Essex County Council Traffic Department. 1.2 Summary of Review and Assessment The Local Air Quality Management (LAQM) regime was first set down in the 1997 National Air Quality Strategy (NAQS) 1 and introduced the idea of local authority Review and Assessment. Government subsequently published policy and technical guidance related to the review and assessment process in 1998. In 2000, Government reviewed the NAQS and set down a revised Air Quality Strategy for England, Scotland, Wales and Northern Ireland 2 (AQS). This set down a revised framework for air quality standards and objectives for seven pollutants, which were subsequently set in Regulation in 2000 through the Air Quality Regulations 2000 3. These were subsequently amended in 2002 4. 1.3 The First Round of Review and Assessment Brentwood Borough Council undertook the first round of review and assessment ( First Round ) between 1998 and 2000. The First Round was a three-stage process, which assessed the sources of seven air pollutants of concern to health: Benzene, 1,3 butadiene, carbon monoxide, lead, nitrogen dioxide (NO 2 ), fine particulates (PM 10 ) and sulphur dioxide. The conclusions of the First Round were that it was expected that all Air Quality Objectives were expected to be met by the target dates based on available information at that time. No Air Quality Management Areas were declared. 1.4 The Second Round of Review and Assessment The second round of review and assessment commenced in 2003. New Technical Guidance (LAQM.TG (03)) 5, Policy Guidance (LAQM.PG (03)) 6 and Progress Report Guidance (LAQM.PRG (03)) 7 were issued on behalf of Defra in 2003. This guidance sets the framework for the requirements of review and assessment for future years, taking account of experiences from the previous round of review and assessment. The Updating and Screening Assessment (USA) was the first phase of the second round of review and assessment. Similar to Stage One of the First Round, there was 1 DoE (1997) The United Kingdom Nation Air Quality Strategy The Stationery Office 2 DETR (2000) The Air Quality Strategy for England, Scotland, Wales and Northern Ireland Working together for Clean Air, The Stationery Office 3 DETR (2000) The Air Quality Regulations 2000, The Stationery Office 4 Defra (2002) The Air Quality Strategy for England, Scotland, Wales and Northern Ireland: Addendum, The Stationery Office 5 Defra (2003) Technical Guidance LAQM.TG(03), Part IV of the Environment Act 1995, Local Air Quality Management, The Stationery Office 6 Defra (2003) Policy Guidance LAQM.PG(03), Part IV of the Environment Act 1995, Local Air Quality Management, The Stationery Office 7 Defra (2003) Progress Report Guidance LAQM.PRG(2003), Part IV of the Environment Act 1995, Local Air Quality Management, The Stationary Office Ref: CS/AQ/AGGX0057/SA/2154 Page 2
consideration of the seven pollutants of concern to health and an assessment was made as to whether Air Quality Objectives for these pollutants would be met. Brentwood Borough Council completed this in September 2003, with the conclusion that a Detailed Assessment was required for nitrogen dioxide (NO 2 ) due to emissions from road traffic on the A12 and at three heavily trafficked junctions: A12/M25 Junction, A128/A1023 Wilson s Corner Junction and High Street/Kings Road Junction. All other Air Quality Objectives are expected to be met. The Department for Environment, Food and Rural Affairs (DEFRA) has accepted the USA conclusions. 1.5 Scope and Methodology of the Detailed Assessment The approach to the Detailed Assessment is to provide the local authority with an opportunity to supplement the information they have gathered in their earlier review and assessment work and more accurately assess the impact of pollution sources on local receptors at identified hotspots, in this case the A12, A12/M25 Junction, A128/A1023 Wilson s Corner Junction and High Street/Kings Road Junction, through dispersion modelling. The aim of the dispersion modelling is to more accurately reflect the results from local monitoring sites across the whole assessment area and allow comparison of pollutant concentrations against the Air Quality Objectives for NO 2. The Detailed Assessment will identify with reasonable certainty whether or not there is likely to be an exceedence of the objectives and if so, define the extent and magnitude of the exceedence. Detailed dispersion modelling has been undertaken using the ADMS-Roads dispersion model using the vehicle emission factors released by DEFRA in 2002. Nitrogen dioxide diffusion tube monitoring carried out within the assessment area has been used to verify and adjust the modelled results accordingly. The bias adjustment factor for diffusion tubes has been estimated through a colocation study with the automatic analyser in Brentwood (grid reference x=559861, y=193617), as described in later sections of this report along with full details of model verification procedures. Short term monitoring data has been annualised in accordance with methodology in the Technical Guidance (LAQM. TG (03)). Pollutant concentrations have been predicted for 2003, the last full year for which data was available, and future year 2005 for nitrogen dioxide. The Detailed Assessment has been undertaken in accordance with the methodologies provided in the Technical Guidance (LAQM. TG (03)). Ref: CS/AQ/AGGX0057/SA/2154 Page 3
2. BASELINE INFORMATION 2.1 Traffic Data Essex County Council provided the annual average daily traffic flows (AADT) and forecast factors for future years used in this assessment. In the absence of speed data, speeds have been based on speed limits, modified according to local conditions to take account of congestion and stop/start vehicle movements at junctions. Speeds were reduced at junctions to 15kph to reflect the higher emissions of queuing traffic. The data used in this assessment, with the forecast vehicle flows for 2005, are shown in Table 1. Ref: CS/AQ/AGGX0057/SA/2154 Page 4
Table 1 Detailed Assessment Traffic data Road No. Road name Direction X Y %HDV Year AADT TEMPRO Factor to 2003 AADT (2003) TEMPRO Factor to 2005 A1023 Brook Street, Brentwood Both 557100 192500 5.6 2002 21904 1.017 22276 1.034 23033 A1023 NE of Brentwood Both 562200 196500 5.6 2002 16296 1.017 16573 1.034 17137 A1023 Shenfield Road, Brentwood Both 560200 194300 5.6 2002 24085 1.017 24494 1.034 25327 A1023 High Street Both 559171 193663 5.5 2001 5873 1.033 6067 1.034 6274 A1023 London Road Both 559171 193663 5.8 2001 6964 1.033 7194 1.034 7439 A12 Brentwood Bypass, Brentwood Both 558600 194800 11.9 2002 67900 1.017 69054 1.034 71402 A128 Brentwood Bypass, Brentwood Both 561500 192400 11.9 2002 17871 1.017 18175 1.034 18793 A128 Ongar Road Both 558600 194900 4.2 2002 18358 1.017 18670 1.034 19305 A128 Ongar Road (N of William Hunter Way) Both 559663 193973 4.6 2001 8033 1.033 8298 1.034 8580 A128 Ingrave Road (N of Queens Rd) Both 559825 193705 5.3 2001 7743 1.033 7998 1.034 8270 A128 Ingrave Road (S of Queens Rd) Both 559825 193705 4.9 2001 7791 1.033 8048 1.034 8322 A129 Ongar Road (S of William Hunter Way) Both 559663 193973 4.4 2001 9174 1.033 9477 1.034 9799 B1002 Roman Road, Mountnessing Both 562600 197300 4.8 2002 7633 1.017 7763 1.034 8027 B185 Kings Road Both 559321 193296 3.0 2001 2772 1.033 2863 1.034 2960 B185 Kings Road Both 559171 193663 2.0 2001 4757 1.033 4914 1.034 5081 B185 Weald Road Both 559171 193663 1.7 2001 5494 1.033 5675 1.034 5868 B185 Weald Road (N of Western Rd) Both 559140 193715 1.4 2001 2088 1.033 2157 1.034 2230 B185 Weald Rd (S of Western Rd) Both 559140 193715 2.3 2001 4970 1.033 5134 1.034 5308 B186 Queens Road Both 559825 193705 1.3 2001 6169 1.033 6372 1.034 6589 M25 M25 Both 555000 194030 18.4 2000 126107 1.052 132665 1.034 137175 M25 M25 Both 557110 191850 18.0 2000 128538 1.052 135222 1.034 139820 M25 M25Junction 28 Off Slip One way 556541 192692 18.4 2003 18753 1.000 18753 1.034 19390 M25 Junction 27-28 One way 556541 192691 18.4 2002 64495 1.017 65591 1.034 67822 M25 M25, Jct. 28 between Off - On Slips Both 556541 192691 18.4 2003 46500 1.000 46500 1.034 48081 M25 M25, Junction 28 On Slip One way 556596 192531 18.4 2003 18503 1.000 18503 1.034 19132 M25 M25, Junction 28-27 One way 556872 192243 18.4 2001 60006 1.033 61986 1.034 64094 M25 M25Junction 28 Off Slip One way 556541 192692 18.4 2002 19961 1.017 20300 1.034 20991 M25 M25, Jct. 28 between Off - On Slips Both 556541 192691 18.4 2002 45803 1.017 46582 1.034 48165 B185 Weald Road Both 558300 194000 4.8 2002 4057 1.017 4126 1.034 4266 U/C Western Road Both 559140 193715 2.3 2001 3896 1.033 4025 1.034 4162 U/C William Hunter Way Both 559663 193973 1.8 2001 4246 1.033 4386 1.034 4535 A128/A1023 Wilsons Corner All links - - 5.3 2001 11722 1.033 12108 1.034 12520 AADT (2005) Ref: CS/AQ/AGGX0057/SA/2154 Page 5
2.2 Air Quality Monitoring Data 2.2.1 Local Monitoring Data Brentwood Borough Council has one continuous air quality monitoring station (grid reference x=559861, y=193617) within the Borough at the Council Offices on Ingrave Road, which was installed in 1995 to more accurately assess levels of NO 2. There are triplicate diffusion tubes co-located at this urban background site. The annual mean NO 2 for 2003 was 35 µg/m 3 i.e. below the 40µg/m 3 Objective level. NO 2 concentrations are measured using a chemiluminescent analyser. The station is calibrated in-house on a fortnightly basis according to the manufacturer s instructions and the data is regularly downloaded and ratified. The manufacturer of the equipment, Enviro Technology, services the station on a six monthly routine basis. In addition to the continuous air quality monitoring station, Brentwood Borough Council also currently operate 53 NO 2 diffusion tubes sites within the Borough, 35 of which are sited within the High Street and A12 assessment areas (areas that are under consideration in this Detailed Assessment). The tubes are supplied and analysed by Harwell Scientifics utilising the 50% TEA 8 in acetone preparation method. Harwell Scientifics participate in the Workplace Analysis Scheme for Proficiency (WASP) for NO 2 diffusion tube analysis and the Annual Field Inter-comparison Exercises. These provide strict performance criteria for participating laboratories to meet, thereby ensuring NO 2 concentration reported are of a high calibre. The Inter-comparison exercises have shown that tubes analysed by this laboratory and method tend to overread continuous analyser results. The results for this analysis method from co-located sites assessed in the Compilation Study 9 by AQ Consultants on behalf of DEFRA indicated that an adjustment factor of +20.5% should be applied. The continuous analyser nitrogen dioxide data has been used with the co-located diffusion tube data to estimate the local bias adjustment factor for the diffusion tubes. The bias adjustment factors for 2000 2003 of 0.77, 0.88, 0.8 and 0.93 have been applied to the diffusion tube data. The corrected NO 2 diffusion tube monitoring results for 2000 2003, with projection to 2005, are shown in Table 2. Monitoring data at the diffusion tube roadside sites within the assessment area have been collated and assessed for model verification purposes. The full verification procedure is shown in Appendix 2. 8 TEA-Triethanolamine 9 Compilation of New Nitrogen Dioxide and PM10 Roadside Monitoring Data Obtained by Local Authorities as Part of the Review and Assessment Process Air Quality Consultants Ltd October 2001 Ref: CS/AQ/AGGX0057/SA/2154 Page 6
Table 2 Diffusion tube monitoring results 2000 2003 in ìg/m 3 Site code Address X Y NO 2 mean (2000) NO 2 mean (2001) NO 2 mean (2002) NO 2 mean (2003) Projected NO 2 2005 BRW 1 Council Offices (co-located site) 559861 193617 30.9 33.7 27.8 34.8 33.0 BRW 2 73 Brook Street 556890 192435 46 51-56.1 53.2 BRW 3 Brook Street 556887 192412 50.5 54.4-53.4 50.6 BRW 4 The Poplars, Brook Street 556958 192285 40.3-39 48.2 45.7 BRW 5 Freeway Cottage, Brook Street (A1023) 557014 192493 52.6 59.8 50.7 59.0 55.9 BRW 6 13 Nags Head Lane 557118 191978 38.2 42 34.8 44.3 42.0 BRW 7 21 Nags Head Lane 557045 191874 28.8 35.8 31.2 42.0 39.8 BRW 8 Angel Cottage, Wrightsbridge Road 555067 194138 29.5 30.4 27.1 33.5 31.7 BRW 9 Lee Farm, Horsemanside 553635 195529 32.9 35.4 31.9 39.4 37.3 BRW 10 Nettlestone, Warley Street (A127) 559442 188795 29.3 32.8 28.3 36.0 34.1 BRW 11 Codham Hall Farm, Codham Hall Lane 558876 188858 30.4 34.1-33.9 32.1 BRW 12 Great Warley Hall 559617 188463 30.4-28.4 35.9 34.0 BRW 13 Homefield Nursery / A127 560301 188785 31.6 36.4 30.7 42.1 39.9 BRW 14 Thorndon Avenue/A127 562405 189146 38 47.6 37.5 46.6 44.2 BRW 15 Meadow House, Arterial Road, A127 563897 189374 29.8 36.6-37.8 35.9 BRW 16 3 High Street 559691 193912 47.7 57.1 48 53.8 51.0 BRW 17 Café Uno, High Street 559643 193889 40.9 47.8 38.9 65.3 61.9 BRW 18 18A High Street 559643 193802 34.1-31.7 41.1 39.0 BRW 19 9 Ingrave Road, A128 559739 193860 42.5 49.2 42.7 53.8 51.0 BRW 20 5/7 Ongar road, A128 559699 193948 47.5 54.7 43.7 55.9 52.9 BRW 21 36 Ongar Road, A128 559604 194035 46.3 51 43 53.0 50.3 BRW 22 Kings Road/Hart Street/High Street 559187 193658 44 47.9 42.3 55.0 52.1 BRW 23 131D High Street 559195 193681 31.4 35.9-39.0 37.0 BRW 24 145 High Street 559148 193660 47.6 - - 48.4 45.9 BRW 25 4 Westbury Road 559085 193601 34.7 38.9 32.4 40.1 38.0 BRW 26 Hamlet Court, Leonard Way 557478 192980 35.8 - - - BRW 27 24 Wingrave Crescent 557379 192900 35.1 38.3 33.8 41.6 39.5 BRW 28 51 Spital Lane 557632 193151 30.8 33.1 31.7 39.6 37.6 BRW 29 46 Selwood Road 557826 193333 31.1 33.9 29.7 35.1 33.3 BRW 30 46 Selwood Road 557826 193333 31.2 33.2 29.9 37.2 35.3 BRW 31 61 Warescot Road 558769 194873 38.9 40.9 37.9 49.9 47.3 BRW 32 76 Warescot Road 558818 194913 40.4 47.1-55.5 52.6 BRW 33 316 Ongar Road 558681 194799 39.5 37.1 34.8 40.9 38.7 Ref: CS/AQ/AGGX0057/SA/2154 Page 7
Table 2 (continued) Diffusion tube monitoring results 2000 2003 in ìg/m 3 Site code Address X Y NO 2 mean (2000) NO 2 mean (2001) NO 2 mean (2002) NO 2 mean (2003) Projected NO 2 2005 BRW 34 339 Ongar Road 558683 194894 37.4 40.4 36.3 49.3 46.7 BRW 35 12 Hurstwood Avenue 558742 194928 42.3 47 43.2 55.8 52.9 BRW 36 Highwood Close 558624 194695 35.7 38.8 34.9 44.1 41.8 BRW 37 9 Porters Close 558455 194421 35.5 40.1 36.8 44.8 42.4 BRW 38 381 Ongar Road 558418 195103 31.5 32.4 27.5 33.8 32.1 BRW 39 Brentwood Centre 559221 195223 38.7 42.9 38.6 52.2 49.5 BRW 40 289 Chelmsford Road 562278 196649 36.2 40.2 35.8 42.3 40.1 BRW 41 Oakwood Cottage, Lower Road 562614 196906 30.5 33.8 27.4 35.0 33.1 BRW 42 36 Church Road 563250 197555 34 35.1 30.9 41.5 39.3 BRW 43 Ingatestone & Fryerning Jnr School 564446 199509 36.5 40.7 35.9 39.6 37.5 BRW 44 No. 1 Trimble Close, Ingatestone 564617 199849 37.3 40.6 36.5 42.6 40.4 BRW 45 New Road, Ingatestone 565186 200071 34.7 39.5 37 46.0 43.6 BRW 46 Beggar Hill 562511 201471 19.7 23.4 18.1 23.6 - BRW 47 Church at Blackmore 560298 201603 19.1 20.7 16.4 - - BRW 48 Woolmongers Lane 558409 202001 23.8 26.1 20 - - BRW 49 108 Doddinghurst Road 559139 195012 40.3 41.4 36.5 43.4 41.1 BRW 50 La Charente, Talbrook 557719 193226 36.6 41 37 43.6 41.4 BRW 51 8 Trimble Close, Ingatestone 564654 199898 - - 41.8 50.1 47.5 Ref: CS/AQ/AGGX0057/SA/2154 Page 8
2.3 Background Concentrations For the NO 2 and NO X assessments, background concentrations have been derived from NETCEN modelled concentration maps for receptors within the assessment areas. Projections of background concentrations to future years have been made using the guidance provided in LAQM.TG (03). The background concentrations used in the assessment are shown in Table 3. Table 5 Background Concentrations in µg/m 3 Assessment Area Year Background NO X Background NO 2 A12 2003 51.0 28.9 A12 2005 46.2 27.0 High Street 2003 49.7 28.4 High Street 2005 45.2 26.6 Ref: CS/AQ/AGGX0057/SA/2154 Page 9
3. DISPERSION MODELLING METHODOLOGY Detailed dispersion modelling of NO X and PM 10 has been undertaken using the Cambridge Environmental Research Consultants (CERC) Ltd ADMS-Roads advanced gaussian air dispersion model. The most recent year s meteorological data (2002) has been used from Stansted meteorological station. The wind rose for the Stansted meteorological data shown below shows the dominant southwesterly wind direction. 330 340 350 0 10 500 20 30 320 400 40 310 50 300 300 60 290 200 70 280 100 80 270 90 260 100 250 110 240 120 230 130 220 140 210 200 0 190 3 6 180 10 170 16 150 160 (knots) Wind speed 0 1.5 3.1 5.1 8.2 (m/s) ADMS-Roads is the latest model in the ADMS family from Cambridge Environmental Research Consultants. Based on the ADMS-Urban system, it can model up to 150 road sources and 7 industrial sources at any one time. The model has been extensively used in local air quality management, and has formed the basis for many AQMA declarations. A considerable number of validation studies have been completed, showing overall excellent agreement between model outputs and observations at continuous monitoring sites. ADMS-Roads has integrated modules to take into account the effects of street canyons and plume chemistry. The most up to date and suitable emissions data for vehicles have been used for the assessment. In line with advice from Department for Transport (DfT) regarding the use of emissions factors for road vehicles, the current assessment has used the Ref: CS/AQ/AGGX0057/SA/2154 Page 10
Emission Factors Toolkit (EFT) to determine emission rates for the dispersion modelling of traffic sources. The EFT is based on the new DfT emission factors as described within the National Atmospheric Emissions Inventory (NAEI). The use of ADMS-Roads allows any number of specific receptors to be identified for the prediction of air quality impacts. The link to GIS allows the use of digital map data to initialise the emissions figures, and also provides the best method of analysing the pollution output. The model can be used to draw detailed concentrations contours of pollutant concentrations (via GIS tools) and allow areas of maximum impacts and any areas of exceedences to be identified. 3.1 Model Verification and Adjustment 3.1.1 NO X /NO 2 Nitrogen dioxide (NO2) and nitric oxide (NO) are both oxides of nitrogen, and are collectively referred to as nitrogen oxides (NO X ). The main source of NO X emissions in the UK is vehicle exhausts, which are converted to NO 2, mainly as a result of reaction with ozone in the atmosphere. The ADMS-Roads dispersion model produces modelled results of the NO X emissions from vehicles and these are then converted to NO 2 for comparison with the Air Quality Objective as outlined below. Background concentrations, as described in Section 2.3, have been added to the modelled contributions of NO X and conversion to NO 2 has been carried out using the NO X : NO 2 ratio using the conversion method in LAQM.TG (03). Verification has been undertaken using 2003 data from 27 diffusion tube sites in the A12 assessment areas and 8 diffusion tube sites in the High Street assessment areas. These sites all have >9 months data capture. The NO X roads contribution factor used in this Detailed Assessment to correct modelled results was 2.0 for the A12 Assessment Areas (trunk road) and 8.7 for the High Street Assessment Areas (urban roadside). The model was found to perform best for modelled trunk road NO X contributions. The full verification process is shown in Appendix 2. Ref: CS/AQ/AGGX0057/SA/2154 Page 11
4. RESULTS Annual average concentrations for NO 2 were predicted for the baseline year 2003 and future year 2005 at: A12 Assessment Areas (5 Areas) 310 specific receptors on the facades of buildings in closest proximity to the A12 Brentwood Bypass and A12/M25 Junction 14000 receptor points forming a regular 10m (maximum) grid across the assessment areas Brentwood High Street Assessment Areas (2 Areas) 70 specific receptors on the facades of buildings in closest proximity to the High Street and High Street/Kings Road and Wilson s Corner Junctions 2050 receptor points forming a regular 10m (maximum) grid across the assessment areas All predicted results have been produced using the methodology described in Section 3 of this report. For the prediction of results for future year 2005, the same verification method has been used but projected background data and forecast traffic data and emissions have been used. 4.1 A12 Brentwood Bypass Assessment Areas A12/M25 Junction Grid reference x1=556520, y1=191780, x2=557200, y2=192580 The maximum annual mean NO 2 concentration was predicted at 73 Brook Street, the nearest sensitive receptor to the A12/M25 junction (Figures 1, 2 and 3 in Appendix 3). The maximum predicted NO 2 concentration in 2005 is 48.4µg/m 3. This is above the annual mean Objective of 40 µg/m 3. There are predicted exceedences of the annual mean Objective at the nearest receptors to the M25 at Nags Head Lane. The maximum predicted NO 2 concentration in 2005 is 47.2 µg/m 3 at 13 Nags Head Lane. A12 Brentwood Bypass (Greenshaw) Grid reference x1=558380, y1=194400, x2=558630, y2=194700 The maximum annual mean NO 2 concentration is predicted at the building facade of 65 Greenshaw, the nearest sensitive receptor to this section of the A12 (Figures 4, 5 and 6 in Appendix 3). The maximum predicted NO 2 concentration in 2005 is 43.8µg/m 3. This is above the annual mean Objective of 40 µg/m 3. A12 Brentwood Bypass (Ongar Road) Grid reference x1=558610, y1=194780, x2=558850, y2=194970 The maximum annual mean NO 2 concentrations are predicted at the nearest receptors to this section of the A12 in Warescot Road and Hurstwood Avenue (Figures 7, 8 and 9 in Appendix 3). The maximum predicted NO 2 concentration in 2005 is 42.5µg/m 3 at the building facade of 69 Warescot Road. This is above the annual mean Objective of 40 µg/m 3. Ref: CS/AQ/AGGX0057/SA/2154 Page 12
A12 Brentwood Bypass (B1002 Roman Road) Grid reference x1=563600, y1=198270, x2=563900, y2=198520 The maximum annual mean NO 2 concentration is predicted at the building facade of the Homestead in Heybridge, the nearest sensitive receptor to this section of the A12 (Figures 10, 11 and 12 in Appendix 3). The maximum predicted NO 2 concentration in 2005 is 43.3µg/m 3. This is above the annual mean Objective of 40 µg/m 3. A12 Brentwood Bypass (Fryerning Lane) Grid reference x1=564320, y1=199500, x2=564740, y2=199920 The maximum annual mean NO 2 concentration is predicted at the building facade of 8 Trimble Close, the nearest sensitive receptor to this section of the A12 (Figures 13, 14 and 15 in Appendix 3). The maximum predicted NO 2 concentration in 2005 is 46.4µg/m 3. This is above the annual mean Objective of 40 µg/m 3. 4.2 Brentwood High Street Assessment Areas High Street/Kings Road The maximum annual mean NO 2 concentration is predicted at the building facade of 147 High Street, the nearest sensitive receptor to the junction (Figures 16, 17 and 18 in Appendix 3). The maximum predicted NO 2 concentration in 2005 is 40.5µg/m 3. This is marginally above the annual mean Objective of 40 µg/m 3. It is expected that the annual mean Objective will be met at all other receptors in close proximity to this junction. As the model is precautionary and there is only one marginal predicted exceedence, it is recommended that monitoring be undertaken at the facade of this receptor to demonstrate compliance with the Objective. A128/A1023 Wilson s Corner Junction The maximum annual mean NO 2 concentration is predicted at the building facade nearest the junction, 1 5 Ingrave Road. (Figures 19, 20 and 21 in Appendix 3). There are also exceedences at the building facades of receptors in the High Street and Ongar Road in close proximity to this Junction. The maximum predicted NO 2 concentration in 2005 is 46.0µg/m 3. This is above the annual mean Objective of 40 µg/m 3. Ref: CS/AQ/AGGX0057/SA/2154 Page 13
5. CONCLUSIONS AND RECOMMENDATIONS Verified modelled results of the A12 Brentwood Bypass assessment areas and A128/A1023 Wilson s Corner Junction for road traffic emissions in 2005 indicate annual mean nitrogen dioxide concentrations at relevant receptor locations will exceed the annual objective of 40µg/m 3. To account for random model error, the Technical Guidance LAQM.TG (03) suggests predicted concentrations above 36µg/m 3 may exceed the objective limit. However, as the approach throughout this Detailed Assessment has been precautionary and model verification has been based on monitoring in a poor air quality year, to add an error factor is likely to be overly precautionary. In order to facilitate the declaration of an AQMA, separate contour lines have been drawn representing the Objective and model uncertainty levels for NO 2. The Council will need to confirm that the exposure criteria with respect to the Objectives are fulfilled before defining the extent of an AQMA. It is recommended that Brentwood Borough Council consider declaring Air Quality Management Areas (AQMAs) on the basis of the potential exceedences at relevant receptors within the A12 Brentwood Bypass assessment areas (see figures 2, 4, 6, 8, and 10 in Appendix 3) and at Wilson s Corner Junction (see figure 14 in Appendix 3). A marginal exceedence of the Objective (40.5ìg/m 3 ) has been predicted in 2005 at the nearest relevant receptor to the High Street/Kings Road Junction. As the model is precautionary, it is recommended that NO 2 monitoring be undertaken at this receptor location to demonstrate compliance with the Objective. It is also recommended that NO 2 monitoring be undertaken at sensitive receptors with the highest predicted concentrations in the other assessment areas where exceedences are predicted to confirm model predictions and provide additional information in support of further assessment work. Ref: CS/AQ/AGGX0057/SA/2154 Page 14
6. APPENDIX 1 MONITORING TRENDS Brentwood NO 2 Diffusion Tubes 2000-2003 70 60 2000 2001 2002 2003 50 NO2 in ug/m 3 40 30 20 10 0 BRW 1 BRW 2 BRW 3 BRW 4 BRW 5 BRW 6 BRW 7 BRW 8 BRW 9 BRW 10 BRW 11 BRW 12 BRW 13 BRW 14 BRW 15 BRW 16 BRW 17 BRW 18 BRW 19 BRW 20 BRW 21 BRW 22 BRW 23 BRW 24 BRW 25 BRW 26 BRW 27 BRW 28 BRW 29 BRW 30 BRW 31 BRW 32 BRW 33 BRW 34 BRW 35 BRW 36 BRW 37 BRW 38 BRW 39 BRW 40 BRW 41 BRW 42 BRW 43 BRW 44 BRW 45 BRW 46 BRW 47 BRW 48 BRW 49 BRW 50 BRW 51 Ref: CS/AQ/AGGX0057/SA/2154 Page 15
7. APPENDIX 2 VERIFICATION OF NO X /NO 2 The ADMS-Roads model has been used to predict the contribution of the road network to annual mean NO X at roadside diffusion tubes sites to verify predicted concentrations. The following information is required: A1 A12 Assessment Areas Annual Mean Concentrations (µg/m 3 ) Total Monitored NO X (1) Total Monitored NO 2 (2) Background NO X (3) Monitored Roadside NO X Contribution (1) (3) Modelled Roadside Contribution NO X (from ADMS-Roads) BRW 2 158.5 56.1 51 107.5 55.6 BRW 3 147.8 53.4 51 96.8 63.5 BRW 4 127.2 48.2 51 76.2 49.4 BRW 5 170 59.0 51 119 34.7 BRW 6 111.8 44.3 51 60.8 51.8 BRW 7 102.7 42.0 51 51.7 56.7 BRW 27 101.1 41.6 51 50.1 27.9 BRW 28 93.2 39.6 51 42.2 27.0 BRW 29 (& 30) 79.8 36.2 51 28.8 23.9 BRW 31 134 49.9 51 83 35.0 BRW 32 156.1 55.5 51 105.1 42.2 BRW 33 98.4 40.9 51 47.4 33.8 BRW 34 131.6 49.3 51 80.6 36.4 BRW 35 157.3 55.8 51 106.3 37.0 BRW 36 111 44.1 51 60 21.0 BRW 37 113.8 44.8 51 62.8 30.7 BRW 38 70.3 33.8 51 19.3 13.5 BRW 39 143.1 52.2 51 92.1 24.9 BRW 40 103.9 42.3 51 52.9 25.9 BRW 41 75 35.0 51 24 22.2 BRW 42 100.7 41.5 51 49.7 29.8 BRW 43 93.2 39.6 51 42.2 19.5 BRW 44 105.1 42.6 51 54.1 40.9 BRW 45 118.5 46.0 51 67.5 35.1 BRW 49 108.2 43.4 51 57.2 18.5 BRW 50 109 43.6 51 58 24.2 BRW 51 134.8 50.1 51 83.8 46.5 Ref: CS/AQ/AGGX0057/SA/2154 Page 16
B1 Brentwood High Street Assessment Areas Annual Mean Concentrations (µg/m 3 ) Total Total Monitored Monitored NO 2 NO X (1) (2) Background NO X (3) Monitored Roadside NO X Contribution (1) (3) Modelled Roadside Contribution NO X (from ADMS-Roads) BRW 16 149.5 53.8 49.7 99.8 12.8 BRW 18 99.5 41.1 49.7 49.8 4.93 BRW 19 149.5 53.8 49.7 99.8 9.7 BRW 20 157.8 55.9 49.7 108.1 12.1 BRW 22 154.2 55.0 49.7 104.5 9.7 BRW 23 91.3 39.0 49.7 41.6 8.4 BRW 24 128.2 48.4 49.7 78.5 8.9 BRW 25 95.6 40.1 49.7 45.9 5.6 Ref: CS/AQ/AGGX0057/SA/2154 Page 17
The modelled roadside NO X from ADMS-Roads is first compared against the monitored roadside NO X, and the average correction factor at each monitoring site is calculated thus: A2 A12 Assessment Areas Annual Mean Concentrations (µg/m 3 ) Monitored Roadside NO X / Modelled Roadside NO X Contribution BRW 2 1.9 BRW 3 1.5 BRW 4 1.5 BRW 5 3.4 BRW 6 1.2 BRW 7 0.9 BRW 27 1.8 BRW 28 1.6 BRW 29 (& 30) 1.2 BRW 31 2.4 BRW 32 2.5 BRW 33 1.4 BRW 34 2.2 BRW 35 2.9 BRW 36 2.9 BRW 37 2.0 BRW 38 1.4 BRW 39 3.7 BRW 40 2.0 BRW 41 1.1 BRW 42 1.7 BRW 43 2.2 BRW 44 1.3 BRW 45 3.2 BRW 49 3.1 BRW 50 2.4 BRW 51 1.8 Average Correction Factor Modelled Roadside NO X 2.0 Ref: CS/AQ/AGGX0057/SA/2154 Page 18
B2 Brentwood High Street Assessment Areas Annual Mean Concentrations (µg/m 3 ) Monitored Roadside NO X / Modelled Roadside NO X Contribution BRW 16 7.8 BRW 18 10.1 BRW 19 10.3 BRW 20 8.9 BRW 22 10.8 BRW 23 5.0 BRW 24 8.9 BRW 25 8.2 Average Correction Factor Modelled Roadside NO X 8.7 Ref: CS/AQ/AGGX0057/SA/2154 Page 19
The average correction factor for modelled roadside NO X is then applied to the original modelled roadside NOx contribution and background NO X is added back in to get the new total modelled NOx concentration. A3 A12 Assessment Areas Annual Mean Concentrations (µg/m 3 ) Modelled Roadside NO X x Average Correction Factor + background NO X = Modelled Total NO X BRW 2 158.5 BRW 3 147.8 BRW 4 127.2 BRW 5 170.0 BRW 6 111.8 BRW 7 102.7 BRW 27 101.1 BRW 28 93.2 BRW 29 (& 30) 79.8 BRW 31 134.0 BRW 32 156.1 BRW 33 98.4 BRW 34 131.6 BRW 35 157.3 BRW 36 111.0 BRW 37 113.8 BRW 38 70.3 BRW 39 143.1 BRW 40 103.9 BRW 41 75.0 BRW 42 100.7 BRW 43 93.2 BRW 44 105.1 BRW 45 118.5 BRW 49 108.2 BRW 50 109.0 BRW 51 134.8 Ref: CS/AQ/AGGX0057/SA/2154 Page 20
B3 Brentwood High Street Assessment Areas Annual Mean Concentrations (µg/m 3 ) Modelled Roadside NO X x Average Correction Factor + background NO X = Modelled Total NO X BRW 16 149.5 BRW 18 99.5 BRW 19 149.5 BRW 20 157.8 BRW 22 154.2 BRW 23 91.3 BRW 24 128.2 BRW 25 95.6 Ref: CS/AQ/AGGX0057/SA/2154 Page 21
The equation from LAQM.TG(03) for the conversion of NO X to NO 2 has been used to calculate the concentration of NO 2. A4 A12 Assessment Areas Annual Mean Concentrations (µg/m 3 ) Conversion of Modelled Total NO X to NO 2 using LAQM.TG (03) [Modelled NO 2 monitored NO 2]/monitored NO 2 x 100 BRW 2 50.8-11.4 BRW 3 53.1-2.9 BRW 4 49.0-0.6 BRW 5 44.1-26.6 BRW 6 49.7 9.8 BRW 7 51.1 19.0 BRW 27 41.6-1.6 BRW 28 41.3 2.5 BRW 29 (& 30) 40.1 9.2 BRW 31 44.2-13.0 BRW 32 46.7-17.5 BRW 33 43.8 5.3 BRW 34 44.7-10.9 BRW 35 44.9-21.0 BRW 36 38.9-12.9 BRW 37 42.7-6.2 BRW 38 35.7 4.5 BRW 39 40.5-23.6 BRW 40 40.9-4.9 BRW 41 39.4 11.2 BRW 42 42.4 0.4 BRW 43 38.3-4.5 BRW 44 46.3 6.5 BRW 45 38.9-16.4 BRW 49 37.9-13.8 BRW 50 40.2-9.2 BRW 51 48.1-6.1 Average % Difference between modelled and monitored NO 2-5.0 Ref: CS/AQ/AGGX0057/SA/2154 Page 22
B4 Annual Mean Concentrations (µg/m 3 ) Brentwood High Street Assessment Areas Conversion of Modelled Total NOx to NO 2 using LAQM.TG(03) [Modelled NO 2 monitored NO 2]/monitored NO 2 x 100 BRW 16 61.4 14.2 BRW 18 43.7 6.3 BRW 19 55.1 2.5 BRW 20 60.0 7.4 BRW 22 55.0 0.0 BRW 23 52.2 33.9 BRW 24 53.2 10.0 BRW 25 45.4 13.3 Average % Difference between modelled and monitored NO 2 10.9 The method described above has been applied to all modelled concentrations of NO X at receptors in the study area to convert to NO 2. Ref: CS/AQ/AGGX0057/SA/2154 Page 23
8. APPENDIX 3 FIGURES Figure 1 2003 Annual Mean NO 2 (ìg/m 3 ) A12/M25 Junction Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=556520, y1=191780, x2=557200, y2=192580. Scale 1:4000. Ref: CS/AQ/AGGX0057/SA/2154 Page 24
Figure 2 2005 Annual Mean NO 2 (ìg/m 3 ) A12/M25 Junction Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=556520, y1=191780, x2=557200, y2=192580. Scale 1:4800. Ref: CS/AQ/AGGX0057/SA/2154 Page 25
Figure 3 2005 Annual Mean NO 2 (ìg/m 3 ) A12/M25 Junction - Contours Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=556520, y1=191780, x2=557200, y2=192580. Scale 1:4800. Ref: CS/AQ/AGGX0057/SA/2154 Page 26
Figure 4 2003 Annual Mean NO 2 (ìg/m 3 ) A12 (Greenshaw) Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558380, y1=194400, x2=558630, y2=194700. Scale 1:2200. Ref: CS/AQ/AGGX0057/SA/2154 Page 27
Figure 5 2005 Annual Mean NO 2 (ìg/m 3 ) A12 (Greenshaw) Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558380, y1=194400, x2=558630, y2=194700. Scale 1:2200. Ref: CS/AQ/AGGX0057/SA/2154 Page 28
Figure 6 2005 Annual Mean NO 2 (ìg/m 3 ) A12 (Greenshaw) Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558380, y1=194400, x2=558630, y2=194700. Scale 1:1700. Ref: CS/AQ/AGGX0057/SA/2154 Page 29
Figure 7 2003 Annual Mean NO 2 (ìg/m 3 ) A12 (Ongar Road) Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558610, y1=194780, x2=558850, y2=194970. Scale 1:1900. Ref: CS/AQ/AGGX0057/SA/2154 Page 30
Figure 8 2005 Annual Mean NO 2 A12 (ìg/m 3 ) (Ongar Road) Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558610, y1=194780, x2=558850, y2=194970. Scale 1:1900. Ref: CS/AQ/AGGX0057/SA/2154 Page 31
Figure 9 2005 Annual Mean NO 2 A12 (ìg/m 3 ) (Ongar Road) - Contours Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558610, y1=194780, x2=558850, y2=194970. Scale 1:1200. Ref: CS/AQ/AGGX0057/SA/2154 Page 32
Figure 10 2003 Annual Mean NO 2 (ìg/m 3 ) A12 (B1002 Roman Road) Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=563600, y1=198270, x2=563900, y2=198520. Scale 1:4000. Ref: CS/AQ/AGGX0057/SA/2154 Page 33
Figure 11 2005 Annual Mean NO 2 (ìg/m 3 ) A12 (B1002 Roman Road) Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=563600, y1=198270, x2=563900, y2=198520. Scale 1:4000. Ref: CS/AQ/AGGX0057/SA/2154 Page 34
Figure 12 2005 Annual Mean NO 2 (ìg/m 3 ) A12 (B1002 Roman Road) - Contours Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=563600, y1=198270, x2=563900, y2=198520. Scale 1:1900. Ref: CS/AQ/AGGX0057/SA/2154 Page 35
Figure 13 2003 Annual Mean NO 2 (ìg/m 3 ) A12 (Fryerning Lane) Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=564320, y1=199500, x2=564740, y2=199920. Scale 1:3400. Ref: CS/AQ/AGGX0057/SA/2154 Page 36
Figure 14 2005 Annual Mean NO 2 (ìg/m 3 ) A12 (Fryerning Lane) Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=564320, y1=199500, x2=564740, y2=199920. Scale 1:3400. Ref: CS/AQ/AGGX0057/SA/2154 Page 37
Figure 15 2005 Annual Mean NO 2 (ìg/m 3 ) A12 (Fryerning Lane)- Contours Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x1=564320, y1=199500, x2=564740, y2=199920. Scale 1:2400. Ref: CS/AQ/AGGX0057/SA/2154 Page 38
Brentwood Borough Council Figure 16 2003 Annual Mean NO2 (ì g/m3) High Street/Kings Road Junction Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558920, y1=193560, x2=559340, y2=193760. Scale 1:1500. Ref: CS/AQ/AGGX0057/SA/2154 Page 39
Brentwood Borough Council Figure 17 2005 Annual Mean NO2 (ì g/m3) High Street/Kings Road Junction Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558920, y1=193560, x2=559340, y2=193760. Scale 1:1500. Ref: CS/AQ/AGGX0057/SA/2154 Page 40
Figure 18 2005 Annual Mean NO 2 (ìg/m 3 ) High Street/Kings Road Junction Contours Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x1=558920, y1=193560, x2=559340, y2=193760. Scale 1:1500. Ref: CS/AQ/AGGX0057/SA/2154 Page 41
Figure 19 2003 Annual Mean NO 2 (ìg/m 3 ) A128/A1023 Wilson s Corner Junction Reproduced with the Permission of Ordnance Survey Crown Copyright. Grid reference x=559708, y=193904. Scale 1:1300 Ref: CS/AQ/AGGX0057/SA/2154 Page 42
Figure 20 2005 Annual Mean NO 2 (ìg/m 3 ) A128/A1023 Wilson s Corner Junction Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x=559708, y=193904. Scale 1:1700. Ref: CS/AQ/AGGX0057/SA/2154 Page 43
Figure 21 2005 Annual Mean NO 2 (ìg/m 3 ) A128/A1023 Wilson s Corner Junction - Contours Reproduced with the Permission of Ordnance Survey Crown Copyright Grid reference x=559708, y=193904. Scale 1:2200. Ref: CS/AQ/AGGX0057/SA/2154 Page 44
Report Statement Casella Stanger completed this report on the basis of a defined programme of works and within the terms and conditions agreed with the Client. This report was compiled with all reasonable skill and care, bearing in mind the project objectives, the agreed scope of works, prevailing site conditions and degree of manpower and resources allocated to the project as agreed. Casella Stanger cannot accept responsibility to any parties whatsoever, following issue of this report, for any matters arising which may be considered outside the agreed scope of works. This report is issued in confidence to the Client and Casella Stanger cannot accept any responsibility to any third party to whom this report may be circulated, in part or in full, and any such parties rely on the contents of the report at their own risk. (Unless specifically assigned or transferred within the terms of the contract, Casella Stanger asserts and retains all copyright, and other Intellectual Property Rights, in and over the report and its contents). Any questions or matters arising from this report may be addressed in the first instance to the Project Manager. Ref: CS/AQ/AGGX0057/SA/2154 Page 45