HEATHROW GATEWAY. Air Quality Assessment Report

Transcription

1 HEATHROW GATEWAY Air Quality Assessment Report 15/04/2014 Revised: 14/05/2014

2 Quality Management Issue/revision Issue 1 Revision 1 Revision 2 Revision 3 Remarks First Issue to Client Revised traffic data Date 15/04/ /05/2014 Prepared by B. Roberts B. Roberts Signature Checked by R. Mew R. Mew Signature Authorised by A. Grossinho A. Grossinho Signature Project number Report number File reference W:\Environmental Planning London\Projects\AQ Projects\ Heathrow Gateway\02 TECHNICAL\08 Reporting\Final W:\Environmental Planning London\Projects\AQ Projects\ Heathrow Gateway\02 TECHNICAL\08 Reporting\Final Project number: Dated: 15/04/ Revised: 14/05/2014

3 Heathrow Gateway Air Quality Assessment Report 15/04/2014 Client McLaren Homes Ltd. Crosside Broadmoor Road Waltham St Lawrence Berkshire RG10 0HY Consultant WSP WSP House 70 Chancery Lane London WC2A 1AF Tel: Fax: Registered Address WSP UK Limited WSP House, 70 Chancery Lane, London, WC2A 1AF WSP Contacts Barry Roberts Tel:

4 Table of Contents Executive Summary Introduction Objectives Description of the Relevant Components of the Proposed Development with Relevance to the Current Assessment Legislation, Policy and Guidance Legislative Framework Policy Framework Guidance Methodology Scope Extent of the Study Area Methods Significance Criteria Selection of Sensitive Receptors Baseline Conditions AQMAs Local Emission Sources Background Air Quality Data Local Air Quality Monitoring Data Identification of Sensitive Receptors Likely Significant Effects Construction Phase Operational Phase Mitigation and Residual Effects Construction Phase Operation Phase Summary and Conclusions References Appendix A Glossary Appendix B EU Limit Values and UK Objectives Appendix C Traffic Data Appendix D Summary of IAQM Construction Phase Impact Assessment Procedure Appendix E Model Verification Calculations Appendix F Summary of EPUK Assessment Significance Criteria 67 Appendix G Assessment Results Appendix H Wind Rose for Heathrow Project number: Dated: 15/04/ Revised: 14/05/2014

5 Executive Summary SCOPE WSP UK (WSP) has been commissioned by McLaren Homes Ltd. to undertake an air quality impact assessment to support the planning application for the proposed residential development in Colnbrook, Berkshire. This report presents the findings of the assessment which addressed the potential air quality impacts during both the construction and operation phases of the proposed development. For both phases, the type, source and significance of potential impacts were identified, and the measures that should be employed to minimise these proposed. METHODS A qualitative assessment of construction-related impacts associated with fugitive dust and PM 10 emissions has been undertaken in line with 2014 Institute of Air Quality Management (IAQM) guidance and suitable mitigation measures identified and recommended. The assessment of the potential air quality impacts associated with the operation phase of the proposed development was completed by WSP following Department of Environment, Food and Regional Affairs (Defra) most recent guidance on local air quality management and the significance of impacts evaluated using Environmental Protection UK (EPUK) guidance and the Air Pollution Exposure Criteria (APEC) contained in the London Council s guidance. The main air quality pollutants of concern (nitrogen dioxide (NO 2 ) and particulate matter (PM 10 )) in association with the operation of the development result from road traffic emissions associated with changes in the traffic volume, vehicle speed and fleet composition at the road network in the local area. Detailed air quality dispersion modelling using ADMS Roads software was undertaken, taking into account the effects of the likely changes in road traffic characteristics associated with the proposed development. Meteorology data supplied by the Met Office for the Heathrow Airport station were used in the model setup. Local air pollution data measured by diffusion tube methods were provided by Slough Borough Council (SBC) and used for model verification purposes. Site specific traffic data for the modelled road network were provided by JNP Group and have been used as input data to the air quality assessment. These traffic data include the contributions of committed developments in the future scenarios. The methodology followed in this study was agreed to by the Team Leader Environmental Quality of SBC, followed current best practice, and used the most up to date tools and data released by Defra for air quality assessment undertakings. FINDINGS Construction Phase Impacts Assessment of the construction related impacts indicated that these will be local to the site, temporary in nature, short-term and of slight adverse to negligible significance prior mitigation. With appropriate use of mitigation measures and good site management, the overall residual effects of dust and PM 10 generation and deposition would be considered to be negligible. Operation Phase Impacts Analysis of the modelled results revealed that the opening of the proposed development in 2019 will cause imperceptible changes to annual mean NO 2 and PM 10 concentrations at the assessment receptors. The results indicate that in all scenarios modelled, the predicted annual mean concentrations of NO 2 at certain modelled receptor locations would exceed the Air Quality Objective for this pollutant, while predicted annual mean PM 10 at all modelled receptor locations would comply with the corresponding Air Quality Objective. The short-term Objectives for both NO 2 and PM 10 are anticipated to be complied with at all modelled receptor locations. 5 78

6 FINDINGS cont. New Exposure According to the London Councils Air Pollution Exposure Criteria (APEC), which has been used as guidance relating to new exposure, the proposed development in the opening year is classed as APEC Level A (i.e. no grounds for refusal of planning application on the grounds of air quality) in respect of annual mean PM 10 concentrations. Predictions of future occupant exposure to annual mean NO 2 concentrations however, are expected to include levels classed as APEC Level A, Level B and Level C. Level C represents future exposure levels which is more than 5% above the objective for the pollutant assessed, and triggers the requirement for significant consideration of mitigation measures to reduce potential exposure to harmful pollution levels. RECOMMENDATIONS Based on the results presented in this assessment, it is recommended that dust suppression/containment techniques and traffic management measures are applied as mitigation measures during the construction phase of the proposed development. It is further recommended that the developer liaises with the local authority throughout this phase of the project, with an aim to minimising impacts from the construction process. The resulting cumulative annual mean concentrations for NO 2 and PM 10 attributable to traffic emissions during the operation phase of the proposed development are sufficiently low so as to not warrant specific mitigation measures being required. The introduction of new exposure into an area with elevated ambient NO 2 concentrations will require mitigation however. The mitigation measures recommended pertain to design aspects as relates to the provision of nonopening windows on street-facing facades and the consideration of mechanical ventilation with suitable filters for NO 2 removal. CONCLUSIONS Overall, this Air Quality Assessment concluded that the proposed development is likely to present temporary, short-term impacts on local air quality of negligible significance during the construction phase after mitigation measures are applied. During the operation phase, there is likely to be a direct, permanent long-term effect on local air quality of negligible significance. With the recommended mitigation measures in place, the proposed development would comply with European and National air quality legislation, and local planning policy. Project number: Dated: 15/04/ Revised: 14/05/2014

7 1 Introduction 1.1 Objectives WSP UK (WSP) has been commissioned by McLaren Homes Ltd. to undertake an air quality assessment for the proposed Heathrow Gateway residential development in Colnbrook, hereafter referred to as the Proposed Development or the Application Site This report presents the findings of an assessment of the potential air quality impacts of the Proposed Development during both its construction and operation phases. For both phases, the type, source and significance of potential impacts are identified, and the measures that should be employed to minimise these described It considers the potential impacts of the Proposed Development on local air quality at public exposure receptor locations, both within and in the vicinity of the Application Site The potential effects of the Proposed Development on local air quality will be assessed using advanced dispersion modelling software (ADMS-Roads), evaluated in the context of relevant UK and European air quality objectives and limit values for the protection of human health (described in Section 2) A glossary of terms used is provided in Appendix A. 1.2 Description of the Relevant Components of the Proposed Development with Relevance to the Current Assessment The Application Site is situated immediately to the east of the junction of London Road and the Colnbrook By-Pass in the suburb of Brands Hill, north of Colnbrook (Figure 1). The Application Site currently comprises incomplete structures where construction of residential units was previously halted The Proposed Development entails the provision of 61 new residential flats within three blocks, a central piazza and parking facilities for 80 vehicle plus cycle storage The Proposed Development has the potential to give rise to changes in air quality at sensitive receptors in the vicinity of the site through fugitive dust emissions associated with the construction phase and the traffic on local roads during both construction and operation phases It is considered that the Proposed Development may have a temporary effect on local air quality during construction, with the storage and handling of aggregates at the site posing the greatest risk with respect to the occurrence of nuisance dust. Construction activities are likely to increase the risk of dust entrainment and possible nuisance occurrence from increased deposition to surrounding surfaces. The assessment of construction phase impacts will focus on likely impacts of airborne and deposited particulate matter in the vicinity of the site. Potential control measures will be evaluated and recommended to mitigate any estimated risks associated with this phase of the Proposed Development Road traffic emits a number of air pollutants, including nitrogen dioxide (NO 2 ) and particulate matter (PM 10 /PM 2.5 ). The quantity of each pollutant emitted from the vehicle exhaust depends on the type of fuel used, engine size, speed of the vehicle, age, driving conditions and the type of emissions abatement equipment fitted, if any. Therefore changes in local traffic characteristics resulting from the operation of the Proposed Development may have an impact on local air quality at sensitive public exposure receptors. 7 78

8 2 Legislation, Policy and Guidance 2.1 Legislative Framework The applicable legislative framework is summarised as follows: a) Air Quality Directive 2008/50/EC (Ref. 1); b) The Air Quality (England) Regulations Statutory Instrument 2000 No.928 (Ref. 2); c) The Air Quality (England) (Amendment) Regulations Statutory Instrument 2002 No.3043 (Ref. 3); d) The Air Quality Standards Regulations Statutory Instrument 2010 No (Ref. 4); e) The Environmental Protection Act 1990 (Ref. 5); and f) The Environment Act 1995 (Ref. 6) These are detailed in the sections below. Air Quality Directive 2008/50/EC The Air Quality Directive 2008/50/EC came into force on the 11 th June This directive merged three existing Directives and one Council Decision into a single Directive on air quality. It sets air quality limit values, target values, and critical levels for a number of air pollutants established by the European Parliament and Council for the protection of human health, vegetation and ecosystems. These are sulphur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), oxides of nitrogen (NO x ) particulate matter smaller than 10µm in aerodynamic diameter (PM 10 and PM 2.5 ), lead (Pb), benzene (C 6 H 6 ), carbon monoxide (CO) and ozone (O 3 ). These have been transposed into UK legislation by the 2010 Regulations It also sets new standards and target dates for reducing concentrations of fine particles. Under the Directive Member States (MS) are required to reduce exposure to PM 2.5 in urban areas by an average of 20% by 2020 based on 2010 levels. The magnitude of the required reduction depends on national average concentrations between 2009 and For the UK, from the 47 PM 2.5 stations used in a study by DEFRA in 2011, it is likely that average PM 2.5 concentrations for will be between 13-14g/m 3. This would require the UK to comply with a 15% reduction target for 2020, equating to a required reduction in average concentrations of around 2.0g/m The directive also obliges MS to meet a PM 2.5 Limit Value of 25µg/m 3 by 2015 and a Limit Value of 20µg/m 3 by Project number: Dated: 15/04/ Revised: 14/05/2014

9 The Air Quality (England) Regulations 2000 and the Air Quality (England) (Amendment) Regulations The UK Government and the devolved administrations published the latest Air Quality Strategy (AQS) for England, Scotland, Wales and Northern Ireland in July 2007 defining both the standards and objectives for each of a range of air pollutants The air quality standards are concentration limits which represent negligible or zero risk to health, based on medical and scientific evidence reviewed by the Expert Panel on Air Quality Standards (EPAQS) and the World Health Organisation (WHO). Above these limits sensitive members of the public (e.g. children, the elderly and the unwell) might experience adverse health effects The objectives set out the extent to which the UK Government and EU expect the standards to be achieved by a certain date and maintained thereafter. They take account of the costs, benefits, feasibility and practicality of achieving the standards. Air Quality Objectives (AQO) which are relevant to the current study (NO 2 and PM 10 ) for the protection of human health are outlined in Appendix B Many of the objectives in the AQS have been made statutory in England with the Air Quality (England) Regulations 2000 and the Air Quality (England) (Amendment) Regulations 2002 for the purpose of Local Air Quality Management (LAQM). These set a series of air quality standards and air quality objectives with the aim of protecting human health The Regulations require that likely exceedences of Air Quality Objectives are assessed in relation to: the quality of the air at locations which are situated outside of buildings or other natural or manmade structures, above or below ground, and where members of the public are regularly present (Stationery Office, 2000 and 2002) The AQO apply only where members of the public are likely to be regularly present for the averaging time of the objectives (i.e. where people will be exposed to pollutants). The annual mean objectives apply to all locations where members of the public might be regularly exposed; these include building façades of residential properties, schools, hospitals, care homes etc. The 24 hour mean objectives apply to all locations where the annual mean objective would apply, together with hotels and gardens of residential properties. The 1 hour mean objectives also apply at these locations as well as at any outdoor location where a member of the public might reasonably be expected to stay for 1 hour or more, such as shopping streets, parks and sports grounds, as well as bus stations and railway stations that are not fully enclosed These periods reflect the varying effects on health of differing exposures to pollutants, for example temporary exposure on the pavement adjacent to a busy road, compared with the exposure of residential properties adjacent to a road. The Air Quality Standards Regulations These Regulations transpose 2008/50/EC into the UK legislation and also incorporate the 4 th air quality daughter directive (2004/107/EC) that sets targets for levels in outdoor air of certain toxic heavy metals (Arsenic (Ar), Cadmium (Cd), Nickel (Ni), Mercury (Hg)), Benzo(a)pyrene and other polycyclic aromatic hydrocarbons (PAHs). Requirements pertaining to PM 10 and PM 2.5 are included in these Regulations. 9 78

10 The Environmental Protection Act Control of dust and particulates associated with construction Section 79 of the Environmental Protection Act 1990 gives the following definitions of statutory nuisance relevant to dust and particles: Any dust, steam, smell or other effluvia arising from industrial, trade or business premises or smoke, fumes or gases emitted from premises so as to be prejudicial to health or a nuisance, and Any accumulation or deposit which is prejudicial to health or a nuisance Following this, Section 80 says that where a statutory nuisance is shown to exist, the local authority must serve an abatement notice. Failure to comply with an abatement notice is an offence and if necessary, the local authority may abate the nuisance and recover expenses There are no statutory limit values for dust deposition above which nuisance is deemed to exist. Nuisance is a subjective concept and its perception is highly dependent upon the existing conditions and the change which has occurred. Environment Act Under Part IV of the Environment Act 1995, local authorities must review and document local air quality within their area by way of staged appraisals and respond accordingly, with the aim of meeting the air quality objectives by the years defined in the Regulations. Where the objectives of the Air Quality Regulations are not likely to be achieved by the objective year, an authority is required to designate an Air Quality Management Area (AQMA). For each AQMA the local authority is required to draw up an Air Quality Action Plan (AQAP) to secure improvements in air quality and show how it intends to work towards achieving air quality standards in the future. 2.2 Policy Framework The applicable policy framework is summarised as follows: a) The Air Quality Strategy for England, Scotland, Wales and Northern Ireland (Volumes 1 and 2) July 2007 (Ref. 7); b) National Planning Policy Framework (March 2012) (Ref. 8); c) The South East Plan 2009 (Ref. 9); d) Slough Local Development Framework Core Strategy (2008) (Ref. 10); and e) Slough s Third Local Transport Plan 2011 (Ref. 11) These are detailed in the sections below. Project number: Dated: 15/04/ Revised: 14/05/2014

11 Air Quality Strategy for England, Scotland, Wales and Northern Ireland The Government's policy on air quality within the UK is set out in the AQS published in July The AQS sets out a framework for reducing hazards to health from air pollution and ensuring that international commitments are met in the UK. The AQS is designed to be an evolving process that is monitored and regularly reviewed. The AQS sets standards and objectives for nine main air pollutants to protect health, vegetation and ecosystems, notably NO 2, PM 10 and PM 2.5, SO 2, O 3, C 6 H 6, 1,3-butadiene (C 4 H 6 ), CO, Pb, and PAHs Of the pollutants included in the AQS, NO 2 and PM 10 are of relevance to this assessment, as they will be emitted from the traffic generated by the Proposed Development. Appendix B presents the limit values and objectives for these pollutants applicable where members of the public are likely to be regularly exposed for the averaging period prescribed. National Planning Policy Framework The Government s overall planning policies for England are described in the National Planning Policy Framework. This document also outlines the means by which Government intends to apply these policies at various levels to achieve its aim of contributing to sustainable development. The Framework acknowledges the importance of appropriate and robust planning at a local level and thus promotes opportunities for communities to engage in plan making at a neighbourhood level. The core underpinning principle of the framework is the presumption in favour of sustainable development, defined as: Development that meets the needs of the present without compromising the ability of future generations to meet their own needs One of the 12 core planning principles in the NPPF is that planning should contribute to conserving and enhancing the natural environment and reducing pollution In relation to air quality, the document states that: Planning policies should sustain compliance with and contribute towards EU limit values or national objectives for pollutants, taking into account the presence of Air Quality Management Areas and the cumulative impacts on air quality from individual sites in local areas. Planning decisions should ensure that any new development in Air Quality Management Areas is consistent with the local air quality action plan ; The planning system should contribute to and enhance the natural and local environment by: preventing both new and existing development from contributing to or being put at unacceptable risk from, or being adversely affected by unacceptable levels of soils, air, water, or noise pollution.. ; In preparing plans to meet development needs, the aim should be to minimise pollution and other adverse effects on the local and natural environment. Plans should allocate land with the least environmental or amenity values, where consistent with other policies in this Framework. ; local planning authorities should focus on whether the development itself is an acceptable use of the land, and the impact of the use, rather than the control of processes or emissions themselves where these are subject to approval under pollution control regimes. Local planning authorities should assume that these regimes will operate effectively. Equally, where a planning decision has been made on a particular development, the planning issues should not be revisited through the permitting regimes operated by pollution control authorities ; and 11 78

12 Local Planning authorities should consider where otherwise unacceptable development could be made acceptable though the use of conditions or planning obligations. Planning Obligations should only be used where it is not possible to address unacceptable impacts through a planning condition. Regional Planning Policy The South East Plan The South East Plan was published in May 2009 and provided guidance on spatial development within the southeast region of England up to This plan was however, revoked almost in its entirety in The only remaining portion of the plan is Policy NRM6: Thames Basin Heaths Special Protection Area. This policy is concerned with the protection of sensitive ecosystems, however it is not relevant to this study, as the Application Site falls well beyond the zone of influence around any designated sites. Local Planning Policy Slough Local Development Framework Core Strategy The Core Strategy makes reference to the impact on local air quality within the borough due to transportation related sources of emissions (mainly roads and air transport) Reference is made to the challenge of meeting development demands, whilst not compromising future residents amenity and right to a healthy environment. The Core Strategy also goes on to note that residential development within the declared AQMAs is not deemed suitable unless appropriate mitigation measures are able to be applied such that impacts are reduced to an acceptable level Following from this, the Core Strategy contemplates that specialist air quality studies would be required to support relevant planning applications, in order to demonstrate the potential impacts that the development would have on local air quality, as well as any air quality related constraints to that development The Core Strategy draws strong links to the Local Transport Plan (see following paragraph) on the basis of acknowledging that road traffic is one of the most significant sources of air pollutants, as well as being an area where bespoke and targeted interventions could lead to secondary benefits (improvements) in air quality One of the policies contained within the Core Strategy is Core Policy 7: Transport, which includes as one of its main targets, a reduction of annual mean NO 2 concentrations to be 35µg/m 3 by Slough s Third Local Transport Plan (LTP3) The Slough Borough Council (SBC) notes in its LTP3 that it has collaborated closely with the Highways Agency in relation to the development of its AQAPs. Further acknowledging the major role of road traffic in relation to local air pollution, a key aim is to take sustainable interventions to reduce the number of vehicles within the borough The Brands Hill area, in which the Application Site is situated, is specifically mentioned within the LTP3 as being an area with poor air quality on account of road traffic emissions The LTP3 has also led to the development of numerous Supplementary Strategy Documents, many of which carry through the acknowledgement of the significant linkage between air quality and road traffic. It follows that these strategies also envisage the improvement of local air quality as a benefit from the specific interventions planned. Project number: Dated: 15/04/ Revised: 14/05/2014

13 The Local Transport Implementation Plan 2012/13 to 2014/15 (endorsed by the SBC in November 2012) notes that an AQAP has been compiled for the AQMAs within the Slough town centre, but not yet for the AQMA at Brands Hill (Slough AQMA No.2). 2.3 Guidance The following guidance documents and publications have been used in this assessment: a) Local Air Quality Management Review and Assessment Technical Guidance LAQM.TG(09) (DEFRA, February 2009) (Ref. 12); b) Local Air Quality Management Review and Assessment Policy Guidance LAQM.PG(09) (DE- FRA, February 2009) (Ref. 13); c) Development Control: Planning for Air Quality (2010 Update) Environmental Protection UK, April 2010 (Ref. 14); d) Institute of Air Quality Management: Guidance on the Assessment of the Impacts of Construction on Air Quality and the Determination of their Significance (February 2014) (Ref. 15); e) London Councils' Air Quality and Planning Guidance (January 2007) (Ref. 16); and f) National Planning Practice Guidance (March 2014) (Ref. 17) These are detailed in the sections below. Local Air Quality Management Review and Assessment Technical Guidance LAQM.TG(09) The Department for Environment, Food and Rural Affairs (DEFRA) has published technical guidance for use by local authorities in their review and assessment work. This guidance, referred to in this document as LAQM.TG(09), has been used where appropriate in the assessment presented herein. This guidance contains a table (Box 1.4) providing examples of where the air quality objectives should/should not apply. Local Air Quality Management Review and Assessment Policy Guidance LAQM.PG(09) This Policy Guidance is principally for local authorities in England to take cognizance of in carrying out their local air quality management under Part IV of the Environment Act The Environment Act 1995 introduced the Local Air Quality Management (LAQM) process to deal with localised hotspots of poor air quality. A principle of LAQM is for local authorities to integrate air quality considerations with other policy areas, such as planning. LAQM.PG(09) states that 'any consideration of the quality of land, air or water and potential impacts arising from development, possible leading to impacts on health, is a material planning consideration where it arises from or affects land use. Development Control: Planning for Air Quality (2010 Update) Environmental Protection UK This air quality guidance produced by Environmental Protection UK (EPUK) offers comprehensive advice on when an air quality assessment may be required, what should be included in an assessment, how to determine the significance of any air quality impacts associated with a development and the possible mitigation measures which may be implemented to minimise these impacts

14 Institute of Air Quality Management: Guidance on the Assessment of Dust from Demolition and Construction This document was produced to provide guidance to developers, consultants and environmental health practitioners on how to undertake a construction impact assessment. The emphasis of the guidance is on classifying the risk of dust impacts from a site which then allow mitigation measures commensurate with that risk to be identified. London Councils' Air Quality and Planning Guidance The London Councils have published guidance for undertaking air quality assessments in the London Boroughs, the majority of which have declared AQMAs. The guidance sets out suggested methods for undertaking such an assessment within the London area and provides a methodology to assist in determining the impacts of a development proposal on air quality. It is acknowledged that the Application Site is not located within London, however in the absence of other suitable guidance pertaining to the evaluation of new exposure introduced as part of a Proposed Development, this guidance has been applied within this assessment. National Planning Practice Guidance The National Planning Practice Guidance (NPPG) was launched on 6th March The NPPG provides an introduction how to identify areas of concern as part of the planning process, details to be considered as part of an air quality assessment, when air quality can be relevant to the planning process and how to mitigate potential effects on local air quality. The NPPG summarises the way that air quality fits into the overall planning management process in the context of UK and EU legislation. Project number: Dated: 15/04/ Revised: 14/05/2014

15 3 Methodology 3.1 Scope The scope of the assessment has been determined in the following way: a) consultation with the Team Leader Environmental Quality (hereafter referred to as the EHO) of SBC to discuss the availability of local monitoring data, the assessment methodology to be applied, and obtain a copy of their latest review and assessment report; b) review of air quality data for the area surrounding the site, including data from SBC, DEFRA (Ref. 18) and the Environment Agency s (EA) websites (Ref. 19); c) desk study to confirm the location of nearby receptors that may be sensitive to changes in local air quality; and d) review of the traffic data provided by JNP Group, which have been used as an input to the air quality assessment It is important to note that the air quality assessment assumed no improvement (reduction) in vehicle emission factors and background concentrations over time between 2012 and The scope of the air quality assessment for the Application Site was agreed with the EHO of SBC. Table 1 provides a summary of the consultation activities undertaken to inform the preparation of this report. Table 1 - Summary of Consultation Undertaken Body/organisation Individual/s at body/organisation Meeting dates and other forms of consultation Summary of outcome of discussions Slough Borough Council Mr Jason Newman (Team Leader Environmental Quality) Formal consultation letter by (21/02/2014) Response (03/03/2014) - Confirmation and agreement of study methodology. Emphasized that the impacts of existing poor air quality on the proposed development would need to be carefully considered and appropriate mitigation measures provided The agreed scope of the current assessment is detailed in the sub-sections below. It includes the assessment of the effects resulting from: a) dust generated by on-site activities on nearby environment during the construction phase; b) particulate matter (PM 10 ) generated by on-site activities on local air quality during the construction phase; c) Increases in pollutant concentrations (namely NO 2 and PM 10 ) as a result of exhaust emissions arising from construction traffic and plant on local air quality; 15 78

16 d) Increases in pollutant concentrations (namely NO 2 and PM 10 ) as a result of exhaust emissions from road traffic generated by the operation of the Proposed Development on local air quality and public exposure; and e) New exposure to ambient air quality concentrations (namely NO 2 and PM 10 ) due to new residential units being operational in the opening year. Increase in dust generated by on-site activities on nearby environment During the site preparation, earthworks and construction activities, associated works may cause dust to be emitted to the atmosphere. Dust comprises particles typically in the size range 1-75µm in aerodynamic diameter and is created through the action of crushing and abrasive forces on materials. Due to this relatively large particle size, dust is only resident in the atmosphere for short periods of time after its initial release and falls out of suspension relatively quickly and in close proximity to the source of emission. Dust is therefore unlikely to cause long-term or widespread changes to local air quality; however, if it is transported beyond the site boundary, dust deposition on property and cars can cause 'soiling' and discolouration. This may result in complaints of nuisance through amenity loss or perceived damage caused Significant increases in dust deposition can also affect sensitive vegetation. Dust can have two types of effects on vegetation: physical and chemical. Direct physical effects include reduced photosynthesis, respiration and transpiration through smothering. Chemical changes to soils or watercourses may lead to a loss of plants or animals, for example via changes in acidity. Indirect effects can include increased susceptibility to stresses such as pathogens and air pollution. These changes are likely to occur only as a result of long-term demolition and construction works adjacent to sensitive habitat. Often these impacts will be reversible once the works are completed and dust emissions cease. Increase in particulate matter (PM 10 ) generated by on-site activities on local air quality The smaller particles of dust (typically less than 10µm in aerodynamic diameter) are known as particulate matter (PM 10 ) or 'suspended particles'. They represent only a small proportion of total dust released. As PM 10 is much smaller in size than dust, it remains suspended in the atmosphere for a longer period and can be transported by wind over a wider area. It is small enough to be drawn into the lungs during breathing, which in sensitive members of the public can cause an adverse reaction. Increase in pollutant concentrations (namely NO 2 and PM 10 ) as a result of exhaust emissions arising from construction traffic and plant on local air quality Traffic associated with the works for site preparation, earthworks and construction activities of the Proposed Development will contribute to traffic levels on the surrounding road network. The greatest potential for effects on air quality from traffic associated with these activities will be in the areas immediately adjacent to the principal means of site access for construction traffic. In addition, exhaust emissions from on-site plant operating during this phase will contribute to local pollutant concentrations in the vicinity of the equipment/plant. Project number: Dated: 15/04/ Revised: 14/05/2014

17 Increase in pollutant concentrations (namely NO 2 and PM 10 ) as a result of exhaust emissions from road traffic generated by the operation of the Proposed Development on local air quality and public exposure Once the Proposed Development is completed, traffic travelling to and from the Application Site may have an effect on local pollutant concentrations, both in and around the site. The main pollutants of concern for road traffic are typically considered to be NO 2, PM 10, CO and C 6 H 6. Of these pollutants, emissions of NO 2 and PM 10 are most likely to result in exceedences of the statutory air quality limit values and objectives. This air quality assessment will therefore only consider these pollutants. New exposure to ambient air quality concentrations (namely NO 2 and PM 10 ) due to the new residential units being operational in the opening year In addition to the above, the potential exposure of future occupants of the Proposed Development to the pollutants of interest will also be assessed. 3.2 Extent of the Study Area The air quality assessment considers the Application Site of the Proposed Development and the immediate surrounding area (up to approximately 750m from the Application Site) For the purpose of assessing the impact of dust and particulate matter arising from the on-site preparation and construction activities on local air quality, an area of up to 350m from the Site boundary and up to 500m from the Application Site entrance has been considered in accordance with guidance published by IAQM (Ref. 15) for trackout For the assessment of the effect of traffic related emissions resulting from traffic associated with the Proposed Development, basic traffic data have been provided for the surrounding road network (details of which are provided in Appendix C) by JNP Group. These include those roads up to approximately 750m distant from the Application Site that were considered likely to have a significant change in traffic volume as a result of the Proposed Development. 3.3 Methods Method of baseline data collection A desk study was undertaken to obtain baseline data to inform the assessment. This study incorporated the following: a) Collation and review of recent local monitoring data and Air Quality Progress Report available from SBC (Ref. 19); b) Review of available air quality data for the area surrounding the Application Site, including data from the DEFRA s online Local Air Quality Management support pages (Ref. 18) and the Environment Agency (EA) s website (Ref. 19); and c) A study of local mapping data available for the study area and the development plan to identify local receptors that may be sensitive to a change in local air quality. This included the use of Ordnance Survey (OS) data which allowed the selection of worst case receptors

18 Assessment of Dust and PM 10 generated by on-site activities on nearby environment and on local air quality A qualitative assessment of the likely significant effects of the generation and dispersion of dust and PM 10 during the construction phase has been undertaken using guidance produced by the IAQM Details of the assessment procedure given in this guidance are summarised in Appendix D and include the consideration of potential dust and PM 10 impacts from demolition, earthworks, general construction activities and track-out The impacts associated with this phase of the Development have been assessed qualitatively by identifying: a) The size of the site and the area of which construction activities are likely to take place; b) The construction activities associated with the Development that could generate dust and their likely duration; c) The proximity and type of sensitive receptors (e.g. schools, residential properties, etc.) to the construction Site boundary; d) The prevailing wind direction in the area in which the Site is located and local precipitation patterns; e) The presence of vegetation or any barriers surrounding the Site, which might act as a buffer; and f) The potential distance which the construction traffic will travel across unpaved roads on the construction Site, prior to accessing the local road network (referred to as trackout ) The potential for dust emissions from the Site during the construction phase was assessed for each activity that is likely to take place. This, together with the sensitivity of the area, defined the risk of dust impacts associated with the site. The following potential impacts of increased dust and PM 10 generated during the construction phase have been considered: a) Annoyance due to dust soiling; b) The risk of health effects due to an increase in exposure to PM 10 ; and c) Harm to ecological receptors The assessment of the risk of dust impacts for each of the four activities (demolition; earthworks; construction; and trackout) took into account both the scale and nature of the works, which determines the potential dust emission magnitude, and the sensitivity of the area Risks were described in terms of there being a low, medium or high risk of dust impacts for each of the four separate potential activities. Where there were low, medium or high risks of an impact, then site-specific mitigation were identified and proposed, proportionate to the level of risk WSP s Air Quality team s professional judgement was used throughout the assessment to ascertain the magnitude of dust and PM 10 emissions associated with each activity occurring during the construction phase of the site, the degree of sensitivity of the affected receptors, and the suitable mitigation measures to be applied to ensure that there will be no significant effect associated with the construction phase of the Proposed Development. Project number: Dated: 15/04/ Revised: 14/05/2014

19 Assessment of the increase in pollutant concentrations (NO 2 and PM 10 ) as a result of exhaust emissions arising from construction traffic and plant on local air quality Exhaust emissions from construction vehicles may have an effect on local air quality both on-site and adjacent to the routes used by these vehicles to access the Application Site. As information on the number of vehicles associated with the each part of the construction phase was not available at the time of undertaking the current assessment, a qualitative evaluation of their overall effect on local air quality has been undertaken by considering: a) The level of construction traffic likely to be generated by this phase of the Proposed Development; b) The number and distance of sensitive receptors in the vicinity of the Application Site and along the likely routes to be used by construction vehicles; and c) The likely duration of the construction phase and the nature of the construction activities undertaken. Assessment of effects of road traffic emissions generated by the operation of the Proposed Development on local air quality (NO 2 and PM 10 ) For the prediction of impacts due to emissions arising from road traffic during operation, the advanced dispersion model ADMS Roads has been used. This model uses detailed information regarding traffic flows on the local road network, surface roughness, and local meteorological conditions to predict pollutant concentrations at selected relevant locations Meteorological data, such as wind speed and direction, are used by the model to determine pollutant transportation and levels of dilution by the wind. Meteorological data used in the model were obtained from the Met Office observing station at Heathrow Airport. This station is considered to provide data representative of the conditions at the Application Site. The meteorological data used for this assessment were from 2012 and For the assessment, the following four scenarios were modelled: a) 2012 Model Verification ; b) 2014 Baseline ; c) 2019 without development / Do Minimum ; and d) 2019 with development / Do Something was used as the model verification year, as this is the latest year for which monitoring and meteorological data were available for use in the verification process. In addition, for a conservative approach, 2012 background pollutant concentrations and emission factors were used for the Baseline year and future assessment scenarios is the proposed completion/opening year of the development A summary of the traffic data and pollutant emission factors used in the assessment can be found in Appendix C. It includes details of Annual Average Daily Traffic flows (AADT), vehicle speeds (kph) and the percentage of Heavy Goods Vehicles (HGVs) for the local road network in all assessment years considered

20 The traffic flows for the without development scenario include flows for committed developments in the locality of the Application Site but does not include any contribution to road traffic from the Proposed Development itself. The traffic flows for the with development scenario includes flows for committed developments and contributions to road traffic from the Proposed Development. The committed developments accounted for include a service station proposed near the Application Site and the proposed Slough Intermodal Freight Exchange (SIFE). Processing of background concentrations The SBC has a number of monitoring sites designated as being representative of urban background conditions, however these are located some distance (more than 2km) from the Application Site Therefore, background concentrations of NO x, NO 2 and PM 10 within the study area for 2012 have been derived from national maps (1 km x 1 km spatial resolution) available from DEFRA (Ref. 18) It is important to note that for NO x and PM 10, the background maps present both the total estimated background concentrations and the individual contributions from a range of emission sources (for example, motorways, aircraft, domestic heating etc.). When detailed modelling of an individual sector is required as part of an air quality assessment, the respective contribution can be subtracted from the overall background estimate to avoid the potential for double-counting Whereas total background concentrations are disaggregated to provide relative contributions from different sources within each grid, all contributions of the in-grid square emissions have been included in total background concentrations used in the assessment given the relatively small network explicitly modelled. Model verification and adjustment The ADMS Roads advanced dispersion model has been widely validated for this type of assessment and is considered to be fit for purpose Model validation undertaken by the software developer will not have included validation in the vicinity of the Proposed Development considered in this assessment. To determine the performance of the model at a local level a comparison of modelled results with local monitoring data at relevant locations was undertaken. This process of verification aimed to minimise modelling uncertainty and systematic error by correcting modelled results by an adjustment factor to gain greater confidence in the final results Model verification has been undertaken following the methodology specified in Annex 3 of LAQM.TG(09) using the NO x :NO 2 calculator available from DEFRA s website to calculate the roadside NO x component of the annual mean NO 2 concentrations measured at the diffusion tube site. Details of the verification calculations are presented in Appendix E To provide a worst case approach to the assessment, 2012 background levels were assumed to be constant up to 2019 to reflect the results of a recent analysis of historical monitoring data collected within a number of sites in England by DEFRA that has identified background levels may not be declining in line with national projections A factor of 2.6 was obtained during the verification process and this factor has been applied to the modelled NO x roads component before conversion to annual mean NO 2 concentrations. Project number: Dated: 15/04/ Revised: 14/05/2014

21 Local monitoring data are not available for concentrations of PM 10, and as such, final modelling results for this pollutant have been adjusted using the factor calculated for adjusting the modelled NO x roads concentrations. This approach is considered to be appropriate according to guidance given in LAQM.TG(09). Processing of results Following model verification and adjustment, the modelled road contribution to NO x concentrations were converted to annual mean NO 2 concentrations using the methodology given in LAQM.TG(09) and the NO x :NO 2 calculator available from DEFRA s website (Ref. 18). The calculator provides a method of calculating NO 2 from NO x wherever NO x emissions from road traffic are predicted using dispersion modelling For PM 10, the adjusted modelled road contribution to annual mean PM 10 concentrations were added to the relevant background concentrations, which were then used to calculate the number of exceedences of the 24-hour mean objective for direct comparison with the relevant AQS objective, following the methodology given in LAQM.TG(09) LAQM.TG(09) does not provide a method for the conversion of annual mean NO 2 concentrations to 1 hour mean NO 2 concentrations. However, research carried out in 2003 (Ref. 21), determined that exceedences of the 1 hour mean objective were unlikely to occur where annual mean concentrations were below 60µg/m 3. Further research carried out in 2008 (Ref. 22) generally supported this relationship and as a result this criterion has been adopted in the current assessment. 3.4 Significance Criteria Construction Phase The significance of effects associated with the construction phase of the Proposed Development has been determined qualitatively and involved the following tasks: a) Evaluation of the proposed Application Site layout, to evaluate size of the site and possible site construction activities that could generate dust and PM 10, their likely location and duration. Limited information on the precise construction plan was available at the time of undertaking the current assessment and hence assumptions were made; b) Collection and appraisal of meteorological data related to wind speed, direction and frequency, and precipitation for the local and wider area; c) Identification of any natural shelters, such as trees, likely to reduce the risk of wind-blown dust; d) In the case of PM 10, mapping of local background concentrations; e) Assessing the potential distance which the construction traffic will travel across unpaved roads on the construction site, prior to accessing the local road network (referred to as trackout ); f) Identification of the location and type of sensitive receptors within 350m of the boundary of the site and/or within 100m of the route(s) used by construction vehicles on the public highway, up to 500m from the site entrance(s) (at-risk receptors). The location of sensitive receptors has involved use of Ordnance Survey data; g) Indication of the number of receptors and sensitivity types at different distances from the site boundary (or dust generating activities wherever known); 21 78

22 h) Assessment of the risk of dust effects arising using three risk categories: low risk, medium risk, and high risk. The site was allocated to a risk category based on two factors: i. the scale and nature of the works, which determined the risk of dust arising (i.e. the magnitude of potential dust emissions) classed as: small, medium or large; and ii. the proximity of receptors, considered separately for ecological and human receptors (i.e. the potential for effects) Activities on construction site have been divided into four types to reflect their different potential effects. These were: a) Demolition; b) Earthworks; c) Construction; and d) Trackout The following terms have been used to define the significance of the impacts identified: a) Major impacts: where the Proposed Development could be expected to have a very significant impacts (either positive or negative) on local air quality; b) Moderate impacts: where the Proposed Development could be expected to have a noticeable impacts (either positive or negative) on local air quality; c) Minor impacts: where the Proposed Development could be expected to result in a small, barely noticeable impacts (either positive or negative) on local air quality; and d) Negligible: where no discernible impacts are expected as a result of the Proposed Development on local air quality The IAQM methodology (Ref. 15) follows a five tier approach to determining the significance of construction phase related impacts comprising the following steps: a) Step One: identifying the requirement for a more detailed assessment. No further assessment is required if there are no receptors within a certain distance of the works; b) Step Two: assessment of the risk of dust impacts for each of the construction activities considered taking into account the potential dust emission magnitude and the sensitivity of the area (considering distance to and type of sensitive receptors); c) Step Three: determination of the site-specific mitigation for each of the potential construction activities identified in Step 2 based on the risk level of dust impacts identified. Where a local authority has issued guidance on measures to be adopted at demolition / construction sites, these are to be taken into account; d) Step Four: examination of the residual effects and determination whether or not these are significant; and e) Step Five: reporting. Project number: Dated: 15/04/ Revised: 14/05/2014

23 Operation Phase The effects of the Proposed Development on local air quality once operational have been evaluated against the significance criteria published by EPUK (Ref. 16) and presented in Appendix F The approach to determining the sensitivity for air quality assessments outlined in the EPUK guidance considers the change in pollutant concentration (magnitude of impact) and the overall pollutant concentrations in the area when compared to the relevant standard. There is no distinction in the sensitivity of different human receptors to air quality. Guidance provided by the IAQM recommends that all population exposure receptors i.e. dwellings, hospitals or schools should all be considered to be of equal sensitivity to air pollution The magnitude of impact is determined quantitatively by establishing the change in pollutant concentration at each receptor as predicted by the detailed modelling. The definitions for the magnitude of impact categories for each pollutant are defined by the size of the change in pollutant concentration in relation to the objective level and are presented in Table 2. Table 2 - Magnitude of Impact Magnitude of Impact Imperceptible Small Medium Large Quantitative Definition Increase or decrease of <1% of AQS objective level Increase or decrease of between 1 5% of AQS objective level Increase of decrease of between 5 10% of AQS objective level Increase of decrease of > 10% of AQS objective level Following the recommendations within the EPUK guidance, the overall pollutant concentration change with the development in place is considered in terms of the percentage of the Objective /Limit Value. The significance matrix used to assess the operation phase effects is presented in Table

24 Table 3 - Significance of Effects Matrix Concentration in Relation to Objective / Limit Value Increase with Proposed Development Negligible or No Change Change in Concentration Small Medium Large Above Objective/Limit Value with scheme (>40 µg/m 3 ) Negligible Slight Adverse Moderate Adverse Substantial Adverse Just Below Objective/Limit Value with scheme (36-40 µg/m 3 ) Negligible Slight Adverse Moderate Adverse Moderate Adverse Below Objective/Limit Value with scheme (30-36 µg/m 3 ) Well Below Objective/Limit Value with scheme (<30 µg/m 3 ) Negligible Negligible Slight Adverse Slight Adverse Negligible Negligible Negligible Slight Adverse Decrease with Proposed Development Above Objective/Limit Value without scheme (>40 µg/m 3 ) Negligible Slight Beneficial Moderate Beneficial Substantial Beneficial Just Below Objective/Limit Value without scheme (36-40 µg/m 3 ) Negligible Slight Beneficial Moderate Beneficial Moderate Beneficial Below Objective/Limit Value without scheme (30-36 µg/m 3 ) Negligible Negligible Slight Beneficial Slight Beneficial Well Below Objective/Limit Value without scheme (<30 µg/m 3 ) Negligible Negligible Negligible Slight Beneficial In addition to these quantitative criteria, the EPUK report outlines a method that uses textual descriptors to identify the differing levels of relative priority that should be afforded to the air quality considerations of a development proposal in the planning process. A summary of the method is given in Table 4. Project number: Dated: 15/04/ Revised: 14/05/2014

25 Table 4 - Summary of Method for Assessing the Significance of Air Quality in the Planning Process Effect of Development Development would lead to a breach or significant (1) worsening of a breach of an EU limit value; cause a new breach to occur, or introduce of new exposure into an exceedence area. Lead to a breach or significant (1) worsening of a breach of an AQ Objective, or cause a new AQMA to be declared, or introduce new exposure into an area of exceedence (2). Development would interfere significantly with or prevent the implementation of actions within an AQ action plan Development would interfere significantly with the implementation of a local AQ strategy. Development would lead to a significant increase in emissions, degradation in air quality or increase in exposure, below the level of a breach of an objective. None of the above. Outcome Air Quality an overriding consideration. Air Quality a high priority consideration. Air Quality a high priority consideration. Air Quality a medium priority consideration. Air Quality a medium priority consideration. Air Quality a low priority consideration. (1) Where the term significant is used, it will be based on the professional judgement of the Local Authority officer. (2) This could include the expansion of an existing AQMA or introduction of new exposure to cause a new AQMA to be declared. Where new exposures is introduced this should be with reference to the exceedence area, and not the AQMA boundary In determining both the significance of new exposure to air pollution and the levels of mitigation required, consideration was given to the Air Pollution Exposure Criteria (APEC) given in Table

26 Table 5 - London Councils Air Pollution Exposure Criteria APEC Level Applicable Range Annual Mean NO 2 Applicable Range PM 10 Recommendation Annual Mean A > 5% below national objective > 5% below national objective 24 hour mean No air quality grounds for refusal; however mitigation of any emissions should be considered. > 1 day less than the national objective B Between 5% below or above national objective Annual Mean Between 5% below or above national objective 24 hour mean Between 1 day above or below the national objective May not be sufficient air quality grounds for refusal, however appropriate mitigation must be considered e.g., maximise distance from pollution source, proven ventilation systems, parking considerations, winter gardens, internal layout considered and internal pollutant emissions minimised. C > 5% above national objective Annual Mean > 5% above national objective 24 hour mean > 1 day more than the national objective Refusal on air quality grounds should be anticipated, unless the Local Authority has a specific policy enabling such land use and ensure best endeavours to reduce exposure are incorporated. Worker exposure in commercial/industrial land uses should be considered further. Mitigation measures must be presented with air quality assessment, detailing anticipated outcomes of mitigation measures. 3.5 Selection of Sensitive Receptors Sensitive locations are those where the public or sensitive ecological habitats may be exposed to pollutants from the Proposed Development. These will include locations sensitive to an increase in dust deposition as a result of on-site construction activities, or exposure to gaseous pollutants from exhaust emissions from construction site traffic and traffic associated with the Proposed Development, once it becomes operational. The sensitivity of the area to dust and PM 10 generated by construction activities has been determined qualitatively using professional judgement and the criteria provided in the IAQM guidance (Appendix D) In terms of public exposure locations that are sensitive to gaseous pollutants emitted from engine exhausts, these will include places where sensitive members of the public are likely to be regularly present and are likely to be exposed to air pollution over the relevant period of time prescribed in current legislation and in the UK Air Quality Objectives (AQO) specified in the UK Air Quality Strategy (AQS) (Ref. 7) Examples of areas representative of public exposure in terms of sensitivity to NO 2 and PM 10 resulting from exhaust emissions from construction site traffic and traffic associated with the Proposed Development, over the relevant averaging periods for these pollutants, are shown in Table 6. Project number: Dated: 15/04/ Revised: 14/05/2014

27 Table 6 - Examples of Relevant Public Exposure Sensitive Locations Averaging Period Relevant Public Exposure Locations Annual mean 24-hour mean 1-hour mean All locations where members of the public might be regularly exposed. Building facades of residential properties, schools, hospitals, care homes etc. All locations where the annual mean objective would apply, together with hotels. Gardens of residential properties. All locations where the annual mean and 24 -hour mean objectives apply. Kerbside sites (for example, pavements of busy shopping streets) Those parts of car parks, bus stations and railway stations etc. which are not fully enclosed, where members of the public might reasonably be expected to spend one hour or more. Any outdoor locations where members of the public might reasonably expected to spend one hour or longer A number of locations were selected to represent relevant public exposure receptors at which pollution concentrations were predicted. The locations of the assessment receptors are shown in Figure 1 of Appendix G. They include locations adjacent or near to the routes that are likely to experience the greatest change in traffic volume as a result of the Proposed Development, as well as locations on the Application Site itself that will be close to the main access routes to the site The relevant receptors were selected from Ordnance Survey Address Layer Two and moved to represent the location of the façade of the building they would represent, which was the nearest to the road sources modelled No ecological statutory designations were identified in the vicinity of the study area and hence no further consideration to these type of receptors is offered in this report

28 4 Baseline Conditions 4.1 AQMAs A review of the latest air quality Progress Report prepared by SBC (Ref. 20) indicates that there are currently four AQMAs declared within the council s jurisdiction Part of the Application Site falls within AQMA Order 2 (which incorporates a stretch of the A4 London Road east of Junction 5 of the M4 motorway up until Sutton Lane) AQMA Order 1 (which incorporates land adjacent to the M4 along the north carriageway between Junctions 5 and 7, plus the south carriageway between Junction 5 and Sutton Lane) is located as close as 410m to the Application Site. 4.2 Local Emission Sources The Application Site is located in an area where air quality is mainly influenced by emissions from road transport (mainly the M4 and A4). The M4 passes as close as 700m to the northwest of the Application Site, while the A4 runs immediately adjacent. 4.3 Background Air Quality Data Table 7 shows the estimated background concentrations for NO x, NO 2 and PM 10 for 2012 that were used in the assessment. Data relate to the grid square into which the Application Site and modelled receptors fall Table 7 also reveals that annual mean background concentrations of, NO 2 and PM 10 within the study area are all below the annual mean Objective for these pollutants (40µg/m 3 for NO 2 and PM 10 ). Table 7 - Estimated Background Concentrations Used in the Assessment (µg/m 3 ) Location / Receptor (OS Coordinates X & Y) Pollutant 2012 (µg/m 3 ) NO x , NO PM Local Air Quality Monitoring Data SBC manages a network of diffusion tubes measuring NO 2 concentrations across its area of jurisdiction. Of the 39 monitoring locations identified within the area, seven were screened as being potentially suitable for the purpose of model verification. These were evaluated in terms of distance to the road, site type, data quality and data capture. Project number: Dated: 15/04/ Revised: 14/05/2014

29 4.4.2 Table 8 presents the description and geographic location of the diffusion tube monitoring sites considered, while Figure 2 in Appendix G provides a spatial representation of the sites taken forward to the verification. Table 8 - Description of Selected Local Authority Diffusion Tube Monitoring Sites Site Name Site Type X (m) Y (m) Suitable for Verification Brands Hill (B) Intermediate* Y London Road (B) Intermediate* Y London Road (C) Intermediate* Y Brands Hill (A) Kerbside N Colnbrook By-Pass Kerbside N London Road (A) Kerbside N Rogans Kerbside N * It is acknowledged that these sites are designated as intermediate, however the distance between these monitoring sites and the kerbside of the nearest roads are considered within a reasonable range to be used for the purpose of model verification in the absence of any suitable roadside designated monitoring sites in the area. Supporting this, LAQM.TG(09) acknowledges that roadside sites can be up to 15m from the kerb Table 9 shows the annual mean NO 2 concentrations measured at the selected diffusion tube monitoring locations. Table 9 - Diffusion Tube Monitoring - Annual Mean NO 2 Concentrations Annual mean concentration (µg/m 3 ) Site name Within AQMA (Bias Adj. = 0.82) (Bias Adj. = 0.989) (Bias Adj. = 0.88) (Bias Adj. = 0.90) 2012 (Modelled Year) Data Capture (%) Brands Hill (B) Y London Road (B) Y London Road (C) Y Analysis of the monitoring results in Table 9 reveals that in 2012, concentrations at two of the monitoring sites were above the annual mean NO 2 objective (40µg/m 3 ), while all three were above in This is expected as they are located within an AQMA

30 4.5 Identification of Sensitive Receptors Table 10 presents a summary of the sensitive receptors within the study area that were modelled. It shows the number of properties identified for each sensitive category for long term public exposure in the vicinity of the Application Site. Figure 2 in Appendix G presents the locations of the modelled existing receptors representative of long term public exposure in the vicinity of the Application Site. Table 10 - Types of Receptors Modelled for Public Exposure Type Number of Properties Residential 9 Schools 0 Children Nurseries 0 Care Homes 0 Hospitals 0 Total Modelled Sensitive Receptors 9 Project number: Dated: 15/04/ Revised: 14/05/2014

31 5 Likely Significant Effects 5.1 Construction Phase During the construction phase, there will be a number of activities which have the potential to generate and/or re-suspend dust and PM 10. These activities have been identified for the construction phase of the Proposed Development and their likely impacts evaluated using the risk assessment approach published by the IAQM The following sections present these sources and the risk assessment results. Main Sources of Dust and PM The main sources of dust and PM 10 during the construction phase may include: a) Site preparation including demolition activities; b) Preparation of temporary access/egress to the Application Site and haulage routes; c) Materials handling, storage, stockpiling, spillage and disposal; d) Movement of vehicles and construction traffic at/within the Application Site; e) Use of crushing and screening equipment/plant; f) Exhaust emissions from site plant, especially when used at the extremes of their capacity and during mechanical breakdown; g) Construction of buildings, roads and areas of hardstanding alongside fabrication processes; h) Internal and external finishing and refurbishment; and i) Site preparation and restoration after completion The majority of the releases are likely to occur during the 'working week'. However, for some potential release sources (e.g. exposed soil produced from significant earthwork activities) in the absence of dust control mitigation measures, dust generation has the potential to occur 24 hours per day over the period during which such activities are to take place. Risk of the Application Site in terms of Dust and PM 10 emissions Assessment of Dust Emission Magnitude The IAQM assessment methodology considers the sources of dust and PM 10 generation in four categories: demolition; earthworks; construction and trackout The generation of dust during these phases of works is classed as large, medium or small. Criteria to determine the dust emission magnitude the Application Site falls into are detailed in Appendix D and results of the assessment are summarised below

32 Demolition Total volume of buildings to be demolished on site is anticipated to be less than 20,000m 3 with construction material presenting low potential for dust release. Therefore the magnitude of dust and PM 10 emissions is considered small for demolition activities. Earthworks No earthworks activities will occur at the Application Site as part of the construction phase of the Proposed Development. Therefore, no further consideration is given to this activity. Construction The total volume of buildings to be constructed on the Application Site is expected to be less than 25,000m 3, but some potentially dusty construction material (e.g. concrete) would likely be used. Therefore the magnitude of dust and PM 10 emissions is considered medium for construction activities. Trackout In the absence of specific information relating to construction traffic, based on experience it is estimated that during the construction phase of the Proposed Development, there are likely to be less than 10 HDV (>3.5t) outward movements in any one day The surface material is likely to have low potential for dust release and due to the small size of the site, the lengths of any unpaved road will be <50m. Therefore, it is considered that the magnitude of dust and PM 10 emissions is small for trackout Table 11 provides the dust and PM 10 emission magnitude for each activity considered during construction of the Proposed Development. Table 11 - Dust and PM 10 emission magnitude for each activity Activity Summary of Each Activity Dust Emission Magnitude Demolition Total volume of buildings to be demolished < 20,000m 3 Small Earthworks No earthworks are proposed N/A Construction Activities Trackout Total building volume <25,000m 3 but potentially dusty material <10 HDV trips per day and <50m of unpaved surface Medium Small Project number: Dated: 15/04/ Revised: 14/05/2014

33 Assessment of Sensitivity of the Study Area As can be seen from the 2013 wind rose data for Heathrow, which is provided in Appendix G, there is strong prevailing wind from the west and southwest. Therefore, receptors located to the east and northeast of the Application Site are more likely to be affected by any dust emitted/re-suspended from any construction activities and track-out Depending on wind speed and turbulence it is likely that the majority of dust would be deposited in the area immediately surrounding the source. It is estimated that there are less than 10 existing residential dwellings located within 20m of the Application Site boundary Local background PM 10 concentrations are, however, low (below 75% of the annual mean objective for this pollutant) and therefore PM 10 generated by the construction phase is unlikely to cause an exceedence of the objectives for this pollutant at the nearby existing properties. The predominant wind direction at the site is from the west and southwest and therefore, for the majority of time it can be assumed that any dust and particulate matter generated by the construction phase will be blown away from neighbouring residential properties The Application Site is on the edge of a suburban district and there are approximately 300 dwellings within 350m of the site Taking the above and guidance produced by the IAQM into account, the area surrounding the Proposed Development is considered to be of medium sensitivity to changes in dust and low sensitivity to changes in PM 10 as a result of construction activities (Table 12). Table 12 - Sensitivity of the Study Area Potential Impact Sensitivity of the Surrounding Area Dust Soiling Human Health Ecological Medium Low N/A According to the IAQM assessment procedure summarised in Appendix D, and based on the available information on the construction phase at the time of writing, the Risk of the Application Site for each of the activities considered is summarised in Table 13. The risk category identified for each activity will define the list of site specific mitigation measures for each relevant construction component. Table 13 - Summary Dust and PM 10 Risk Table to Define Site-Specific Mitigation Potential Impact Risk Demolition Earthworks Construction Trackout Dust Soiling Low Risk N/A Medium Risk Low Risk Human Health Negligible N/A Low Risk Negligible Ecological N/A N/A N/A N/A 33 78

34 Taking into account all of the above, the overall sensitivity of the surrounding area in terms of human receptors is medium, and the overall magnitude of change prior to mitigation is considered to be medium to small. Therefore overall, there is likely to be a direct, temporary, short-term impact on nearby residential properties of slight adverse to negligible significance prior to the implementation of mitigation measures. Construction Traffic Exhaust emissions from site preparation, earthworks and construction traffic and plant will contribute to local pollutant concentrations. The greatest potential for effects on air quality from traffic associated with the construction activities will be in the areas immediately adjacent to the principal means of site access for construction/site traffic At the time of writing, the exact number of vehicles and plant required during construction activities was not known. In addition, there will also be a requirement to deliver equipment and materials to and from the Application Site and additional vehicle trips associated construction staff/workers travelling to and from the site The proposed route for the construction traffic was also unconfirmed at the time of writing. The greatest impact on air quality from traffic associated with the construction phase will be in the areas immediately adjacent to the site access. It is anticipated that construction traffic will likely access the site via London Road or the Colnbrook By-Pass. There are residential properties directly adjacent to London Road route The sensitivity of the receptors is high to medium; the magnitude of change prior to mitigation is anticipated to be small. The maximum annual mean concentrations of NO 2 and PM 10 in the opening year are estimated to be above and below their objectives respectively, therefore the impacts are considered to be temporary, short-term, local in effect and of slight adverse to negligible significance prior to mitigation. 5.2 Operational Phase Annual mean NO 2, and PM 10 concentrations have been predicted at selected relevant receptors located within 200m of the modelled road network for the Baseline year (2014) and for the without development ( Do Minimum ) and with development ( Do Something ) scenarios in the opening year (2019) Summaries of estimated results are presented in Table 14 to Table 19 and discussed in the following sub-sections. Results are evaluated in the light of current objectives and limit values for the relevant pollutants, and the significance of impacts rating presented. Impact of Traffic Emissions on Annual Mean NO 2 concentrations The objective for annual mean NO 2 concentrations is 40µg/m 3 to be achieved by the end of 2005 and thereafter. The preliminary results of the assessment show that in the 2014 Baseline scenario, concentrations are below the objective at all of the assessment receptor locations. The highest predicted concentration is 47.3µg/m 3 at Receptor 4 (an existing residential property located alongside London Road) Table 14 shows the number of relevant receptors per annual mean concentration ranges for the various scenarios, at existing public exposure locations. Project number: Dated: 15/04/ Revised: 14/05/2014

35 Table 14 - Predicted Annual Mean NO 2 Concentration at Existing Receptors in Baseline, DM and DS Scenarios Annual Mean NO 2 Concentration (µg/m 3 ) Number of Receptors Baseline Number of Receptors DM Number of Receptors DS < > Total The highest predicted concentrations, identified at Receptor 3 (existing residential property along London Road), are 57.4µg/m 3 in both the without development and with development scenarios. These concentrations exceed the annual mean objective for this pollutant In the opening year, the Proposed Development will result in imperceptible changes (decreases) in annual mean NO 2 concentrations at the assessed receptors Table 15 summarises the operation phase significance of impacts for NO 2. Table 15 - Predicted NO 2 Significance Effect at Existing Receptors in Relation to the Operation Phase Significance Number of Receptors % Substantial Adverse 0 0 Moderate Adverse 0 0 Slight Adverse 0 0 Negligible Slight Beneficial According to the EPUK significance criteria, the effect of the Proposed Development on annual mean NO 2 concentrations prior to mitigation is negligible. Impact of Traffic Emissions on Hourly Mean NO 2 Concentrations The objective for hourly mean NO 2 concentrations is a concentration of 200µg/m 3 as the 99.8 th percentile of hourly mean concentrations to be achieved by the end of 2005 and every year thereafter As the annual mean NO 2 concentrations predicted by the model in the opening year are all below 60µg/m 3, exceedences of the hourly mean NO 2 concentration objective are unlikely to occur within the study area The impact of the Proposed Development on hourly mean NO 2 concentrations is hence predicted to be direct, permanent, long term and negligible

36 Impact of Traffic Emissions on Annual Mean PM 10 Concentrations The objective for annual mean PM 10 concentrations is 40µg/m 3 to be achieved by the end of 2004 and thereafter. The results of the assessment show that in the 2014 Baseline scenario, concentrations are below the objective at all of the assessment receptor locations. The highest predicted concentration is 22.7µg/m 3 at Receptor 3 (an existing residential receptor alongside London Road) Table 16 shows the number of relevant receptors per annual mean concentration ranges for the various scenarios, at existing public exposure locations. Table 16 - Predicted Annual Mean PM 10 Concentration at Existing Receptors in Baseline, DM and DS Scenarios Annual Mean PM 10 Concentration (µg/m 3 ) Number of Receptors Baseline Number of Receptors DM Number of Receptors DS < > Total It is observed there will be no exceedences of the annual mean objective, with the highest predicted concentrations identified at Receptor 3 being 24.1µg/m 3 for both the without development and with development scenarios In the opening year, the Proposed Development will result in imperceptible changes in annual mean PM 10 concentrations at the assessed receptors Table 17 summarises the operation phase significance of effects for PM 10. Table 17 - Predicted PM 10 Significance Effect at Existing Receptors in Relation to the Operation Phase Significance Number of Receptors % Substantial Adverse 0 0 Moderate Adverse 0 0 Slight Adverse 0 0 Negligible Slight Beneficial According to the EPUK significance criteria, the effect of the Proposed Development on annual mean PM 10 concentrations prior to mitigation is negligible. Project number: Dated: 15/04/ Revised: 14/05/2014

37 Impact of Traffic Emissions on Daily Mean PM 10 Concentrations The objective for 24 hourly mean PM 10 concentrations is 50µg/m 3 to be exceeded no more than 35 times a year by the end of 2004 and thereafter. The results of the dispersion modelling show that in the 2014 Baseline case, the number of exceedences is a maximum of 8 days, which is below the objective The maximum number of days of exceedence in 2019 is 10 days, both with and without the Proposed Development operational. The Proposed Development will therefore not lead to an increase in the number of days of exceedence at the modelled receptor locations According to the EPUK significance criteria, the effect of the Proposed Development on daily mean PM 10 concentrations is negligible i.e. no significant effect. New Exposure The highest predicted annual mean NO 2 concentration within the Application Site is 57.2µg/m 3 (Receptor 10, which represents exposure at a ground floor location within the northwest corner of Block A). According to the London Councils Air Pollution Exposure Criteria (APEC) a number of future receptor locations within the Proposed Development are classed as APEC Level B or Level C in terms of annual mean NO 2 concentrations for on-site receptors on the in the opening year (see Table 18). Table 18 - Predicted NO 2 Significance Impact at Proposed Receptors as per APEC APEC Number of New Exposure Receptors A 14 B 9 C 7 Total The highest predicted annual mean PM 10 concentration within the Application Site is 23.1µg/m 3 (Receptor 10). Therefore, according to the London Councils APEC, the Proposed Development is classed as APEC Level A in terms of annual mean PM 10 concentrations at on-site receptors in the opening year i.e. no air quality grounds for refusal. Table 19 - Predicted PM 10 Significance Impact at Proposed Receptors as per APEC APEC Number of New Exposure Receptors A 30 B 0 C 0 Total

38 6 Mitigation and Residual Effects 6.1 Construction Phase Mitigation The mitigation measures to be implemented to eliminate the identified risk of dust and PM 10 emissions associated with the various activities of the construction phase of the proposed development (demolition, earthworks, construction and trackout) are listed below. These can be enshrined within a CEMP if necessary The Proposed Development site is considered to represent a Medium to Low Risk. A comprehensive list of mitigation measures is detailed below with a level of recommendation. General Communication It is recommended that liaison with the local authority be maintained throughout the construction process. Detailed mitigation measures to control construction traffic should be discussed with MC to establish the most suitable access and haul routes for the site traffic. The most effective mitigation will be achieved by ensuring that construction traffic does not pass along sensitive roads (residential roads, congested roads, via unsuitable junctions, etc.) where possible, and that vehicles are kept clean (through the use of wheel washers, etc.) and sheeted when on public highways. Timing of large-scale vehicle movements to avoid peak hours on the local road network could also be beneficial. Highly Recommended A stakeholder communications plan that includes community engagement before work commence son site is to be developed and implemented. A comments and complaints register which is accessible to members of public should be implemented and maintained. Such a register would provide a formal framework within which to record any comments and complaints received, as well as to identify and action appropriate mitigation and/or remediation measures. The register should also include a means of recording and communicating the close-out of issues. Highly Recommended The name and contact details of person(s) accountable for air quality and dust issues on the site boundary need to be displayed. This may be the environment manager/engineer or the site manager. The head or regional office contact information is also to be displayed. Highly Recommended. General Dust Management Site Management Record all dust and air quality complaints must be recorded and cause identified, and appropriate measures taken to reduce emissions in a timely manner, and record the measures taken. Highly Recommended The complaints log is made available to the local authority when asked. Highly Recommended Any exceptional incidents that cause dust and/or air emissions, either on- or offsite need to be recorded, and the action taken to resolve the situation recorded in the log book. Highly Recommended. Project number: Dated: 15/04/ Revised: 14/05/2014

39 6.1.9 Regular liaison meetings with other high risk construction sites within 500m of the site boundary need to be held, to ensure plans are co-ordinated and dust and particulate matter emissions are minimised. It is important to understand the interactions of the off-site transport/ deliveries which might be using the same strategic road network routes. Highly Recommended. Monitoring A daily on-site and off-site inspection to be undertaken, where receptors (including roads) are nearby, to monitor dust, record inspection results, and make the log available to the local authority when asked. This should include regular dust soiling checks of surfaces such as street furniture, cars and window sills within 100m of site boundary, with cleaning to be provided if necessary. Desirable Regular site inspections to monitor compliance with the DMP are to be carried out, inspection results recorded, and an inspection log made available to the local authority when asked. Highly Recommended Increase the frequency of site inspections by the person accountable for air quality and dust issues on site when activities with a high potential to produce dust are being carried out and during prolonged dry or windy conditions. Highly Recommended. Preparing and maintaining the site Plan site layout so that machinery and dust causing activities are located away from receptors, as far as is possible. Highly Recommended Erect solid screens or barriers around dusty activities or the site boundary that are at least as high as any stockpiles on site. Highly Recommended Fully enclose site or specific operations where there is a high potential for dust production and the site is actives for an extensive period. Highly Recommended Avoid site runoff of water or mud. Highly Recommended Keep site fencing, barriers and scaffolding clean using wet methods. Highly Recommended Remove materials that have a potential to produce dust from site as soon as possible, unless being re-used on site. If they are being re-used on-site cover as described below. Highly Recommended Cover, seed or fence stockpiles to prevent wind whipping. Highly Recommended. Operating vehicle/machinery and sustainable travel Ensure all vehicles switch off engines when stationary - no idling vehicles. Highly Recommended Avoid the use of diesel or petrol powered generators and use mains electricity or battery powered equipment where practicable. Highly Recommended Impose and signpost a maximum-speed-limit of 15 mph on surfaced and 10 mph on unsurfaced haul roads and work areas (if long haul routes are required these speeds may be increased with suitable additional control measures provided, subject to the approval of the nominated undertaker and with the agreement of the local authority, where appropriate). Desirable Produce a Construction Logistics Plan to manage the sustainable delivery of goods and materials. Highly Recommended Implement sustainable transport measures including public transport, cycling, walking, and carsharing. Desirable

40 Operations Only use cutting, grinding or sawing equipment fitted or in conjunction with suitable dust suppression techniques such as water sprays or local extraction, e.g. suitable local exhaust ventilation systems. Highly Recommended Ensure an adequate water supply on the site for effective dust/particulate matter suppression/mitigation, using non-potable water where possible and appropriate. Highly Recommended Use enclosed chutes and conveyors and covered skips. Highly Recommended Minimise drop heights from conveyors, loading shovels, hoppers and other loading or handling equipment and use fine water sprays on such equipment wherever appropriate. Highly Recommended Ensure equipment is readily available on site to clean any dry spillages, and clean up spillages as soon as reasonably practicable after the event using wet cleaning methods. Highly Recommended. Waste management Avoid bonfires and burning of waste materials. Highly Recommended. Measures Specific to Demolition Soft strip inside buildings before demolition (retaining walls and windows in the rest of the building where possible, to provide a screen against dust). Desirable Ensure that effective water suppression is used during demolition operations. Hand held sprays are more effective than hoses attached to equipment as the water can be directed to where it is needed. In addition high volume water suppression systems, manually controlled, can produce fine water droplets that effectively bring the dust particles to the ground. Highly Recommended Avoid explosive blasting, using appropriate manual or mechanical alternatives. Highly Recommended Bag and remove any biological debris or damp down such material before demolition. Highly Recommended. Measures Specific to Construction Avoid scabbling (roughening of concrete surfaces) if possible. Desirable Ensure sand and other aggregates are stored in bunded areas and are not allowed to dry out, unless this is required for a particular process, in which case ensure that appropriate additional control measures are in place. Highly Recommended Ensure bulk cement and other fine powder materials are delivered in enclosed tankers and stored in silos with suitable emission control systems to prevent escape of material and overfilling during delivery. Desirable For smaller supplies of fine power materials ensure bags are sealed after use and stored appropriately to prevent dust. Desirable All construction plant and equipment should be ensured to be maintained in good working order and not left running when not in use. Highly Recommended. Project number: Dated: 15/04/ Revised: 14/05/2014

41 Design controls for construction equipment and vehicles could be implemented and only appropriately designed vehicles will be used for materials handling. Highly Recommended. Measures Specific to Trackout Use water-assisted dust sweeper(s) on the access and local roads, to remove, as necessary, any material tracked out of the site. This may require the sweeper being continuously in use. Highly Recommended Avoid dry sweeping of large areas. Highly Recommended Ensure vehicles entering and leaving sites are covered to prevent escape of materials during transport. Highly Recommended Inspect on-site haul routes for integrity and instigate necessary repairs to the surface as soon as reasonably practicable. Highly Recommended Record all inspections of haul routes and any subsequent action in a site log book. Highly Recommended Install hard surfaced haul routes, which are regularly damped down with fixed or mobile sprinkler systems, or mobile water bowsers and regularly cleaned. Highly Recommended Implement a wheel washing system (with rumble grids to dislodge accumulated dust and mud prior to leaving the site where reasonably practicable). Highly Recommended Ensure there is an adequate area of hard surfaced road between the wheel wash facility and the site exit, wherever site size and layout permits. Highly Recommended Access gates to be located at least 10m from receptors where possible. Highly Recommended On-site movements could be restricted to well within site and not near the perimeter, if possible. Highly Recommended Regular inspection of local highways and site boundaries to check for dust deposits should be conducted. If necessary, cleaning and/or removal could be undertaken. Highly Recommended Vehicles carrying loose aggregate and workings should be sheeted at all times; Highly Recommended. Other General Good Practice Measures Dust-suppressed tools can be used for all operations Unauthorised burning of any material anywhere on site should not be tolerated Vehicle deliveries could be pre-arranged and scheduled to avoid the need for vehicles to wait on surrounding roads prior to entering the site. Residual Effects The overall significance of the effects arising from the construction phase of the Proposed Development following the implementation of the mitigation measures described above and good site practice is shown in the Table

42 Table 20 - Construction Phase Summary Significance Table with Mitigation Potential Impact Risk Demolition Earthworks Construction Trackout Dust Soiling Negligible Negligible Negligible Negligible Human Health Negligible Negligible Negligible Negligible Ecological N/A N/A N/A N/A Overall Significance Negligible With appropriate use of mitigation measures and good site management the overall residual effects of dust and PM 10 generation and deposition would be considered to be negligible The residual effects of emissions from construction vehicles overall would be negligible. 6.2 Operation Phase Mitigation The resulting contributions (attributable to traffic emissions) to the cumulative annual mean concentrations for NO 2 and PM 10 during the operation phase of the Proposed Development are sufficiently low so as to not warrant specific mitigation measures being required in this respect The introduction of new exposure into an area with elevated ambient NO 2 concentrations will require mitigation however. It is therefore recommended that designs consider the provision on non-opening windows for at least the street-facing facades of flats on the ground, 1 st and 2 nd floors Further to this, it is recommended that a means of mechanical ventilation (ideally with its intake at roof level, or at an elevated position within the central portion of the site (away from surrounding roads)) be considered for all residential units within the Proposed Development. Should elevated or optimally located intakes not be able to be achieved, the ventilation strategy should introduce a suitable filtration system to reduce NO 2 concentrations drawn into the ventilation system intakes to below legislated limit values. Details of the ventilation systems should be provided at detailed design stage for review and agreement by the local authority. Residual Effects Overall, the residual effect of the Proposed Development on local air quality will remain of negligible significance Once mitigation measures as described above are implemented, future occupants of the Proposed Development would not be exposed to annual mean NO 2 or PM 10 concentrations that exceed the AQS objectives. Project number: Dated: 15/04/ Revised: 14/05/2014

43 7 Summary and Conclusions A qualitative assessment of the potential effects on local air quality from construction activities has been carried out for this phase of the Proposed Development based on the IAQM construction assessment procedure. This assessment identified that the Proposed Development is considered to be a Medium to Low Risk Site overall for general construction activities. However, through good site practice and the implementation of suitable mitigation measures, the effect of dust and PM 10 releases would be reduced and excessive releases prevented. The residual effects of the construction phase on air quality would therefore considered to be temporary, short-term, local and of negligible significance A quantitative assessment of the potential effects during the operation phase was undertaken using advanced dispersion modelling to predict the changes in NO 2 and PM 10 concentrations that would occur due to traffic generated by the Proposed Development The results show that the Proposed Development would cause imperceptible changes to annual mean NO 2 and PM 10 concentrations at the assessment receptors. The effects of the operation phase are considered to be of negligible significance for both NO 2 and PM 10. Therefore, there is likely to be a direct, permanent long-term effect on local air quality of negligible significance The results of the assessment showed that the predicted annual mean NO 2 concentrations at certain receptor points representing new exposure locations within the Application Site were close to, or exceeded the objective for this pollutant. Using the London Council s exposure criteria for annual mean NO 2 concentrations at residential dwellings, the Proposed Development was determined to represent future exposures classed as APEC Level A, Level B and Level C. Level C represents future exposure which is more than 5% above the objective for the pollutant assessed, and triggers the requirement for significant consideration of mitigation measures to reduce potential exposure. It also highlights that this aspect (how it has been evaluated and how it will be managed moving forward) would be given high priority within the planning process Using the London Council s exposure criteria for annual mean PM 10 concentrations at residential dwellings, the entire Proposed Development was determined to represent future exposures classed as APEC Level A (no grounds for air quality refusal) It is important to note that the air quality assessment assumed no improvement (reduction) in vehicle emission factors and background concentrations over time between 2012 and This is therefore considered to represent a worst case assessment of future NO 2 and PM 10 concentrations within the vicinity of the Proposed Development Overall, with the recommended mitigation measures in place, the Proposed Development would comply with European and National air quality legislation, and local planning policy

44 8 References [1] Air Quality Directive 2008/50/EC [2] The Air Quality (England) Regulations Statutory Instrument 2000 No.928 [3] The Air Quality (England) (Amendment) Regulations Statutory Instrument 2002 No.3043 [4] The Air Quality Standards Regulations Statutory Instrument 2010 No [5] The Environmental Protection Act 1990 [6] The Environment Act 1995 [7] The Air Quality Strategy for England, Scotland, Wales and Northern Ireland (Volumes 1 and 2) July 2007 [8] National Planning Policy Framework 2012 [9] The South East Plan 2009 [10] Slough Local Development Framework Core Strategy Development Plan Document LDF 42 (December 2008) [11] Slough s Third Local Transport Plan 2011 [12] Local Air Quality Management Review and Assessment Technical Guidance LAQM.TG(09) (Defra, February 2009) [13] Local Air Quality Management Review and Assessment Policy Guidance LAQM.PG(09) (Defra, February 2009) [14] Development Control: Planning for Air Quality (2010 update) Environmental Protection UK, April 2010 [15] Institute of Air Quality Management: Guidance on the Assessment of Dust from Demolition and Construction 2014 [16] London Councils' Air Quality and Planning Guidance 2007 [17] National Planning Practice Guidance (March 2014) [18] DEFRA Local Air Quality Management (LAQM) Support Pages. Available at: [19] Environment Agency s What s in your backyard? pollution register. Available at: [20] Slough Borough Council 2013 Air Quality Progress Report [21] D Laxen and B Marner (July 2003) Analysis of the relationship between 1-hour and annual mean nitrogen dioxide at UK roadside and kerbside monitoring sites [22] A Cook (2008) Analysis of the relationship between annual mean nitrogen dioxide concentration and exceedences of the 1-hour mean AQS Objective Project number: Dated: 15/04/ Revised: 14/05/2014

45 Appendix A Glossary Term AADF/T Annual Average Daily Flow/Traffic Adjustment Accuracy Air quality objective Air quality standard Ambient air Annual mean AQMA AURN Conservative Data capture DEFRA DfT EIA Emission rate Exceedence Fugitive emissions Definition A daily total traffic flow (24 hrs), expressed as a mean daily flow across all 365 days of the year. Application of a correction factor to modelled results to account for uncertainties in the model A measure of how well a set of data fits the true value. Policy target generally expressed as a maximum ambient concentration to be achieved, either without exception or with a permitted number of exceedences within a specific timescale (see also air quality standard). The concentrations of pollutants in the atmosphere which can broadly be taken to achieve a certain level of environmental quality. The standards are based on the assessment of the effects of each pollutant on human health including the effects on sensitive sub groups (see also air quality objective). Outdoor air in the troposphere, excluding workplace air. The average (mean) of the concentrations measured for each pollutant for one year. Usually this is for a calendar year, but some species are reported for the period April to March, known as a pollution year. This period avoids splitting winter season between 2 years, which is useful for pollutants that have higher concentrations during the winter months. Air Quality Management Area. Automatic Urban and Rural (air quality monitoring) Network, managed by contractors on behalf of DEFRA and the Devolved Administrations. Tending to over-predict the impact rather than under-predict. The percentage of all the possible measurements for a given period that were validly measured. Department for Environment, Food and Rural Affairs. Department for Transport. Environmental Impact Assessment. The quantity of a pollutant released from a source over a given period of time. A period of time where the concentrations of a pollutant is greater than, or equal to, the appropriate air quality standard. Emissions arising from the passage of vehicles that do not arise from the exhaust system

46 HDV/HGV LAQM Line source Minor roads Model adjustment NO 2 NO x Percentile Heavy Duty Vehicle/Heavy Goods Vehicle. Local Air Quality Management. Emission source considered to be mobile and to follow a well-defined path (e.g., road transport). Non A roads or Motorways. Following model verification, the process by which modelled results are amended. This corrects for systematic error. Nitrogen dioxide. Nitrogen oxides. The percentage of results below a given value. PM 10 Particulate matter with an aerodynamic diameter of less than 10 micrometres. Ratification (Monitoring) Road link True Value µg/m 3 microgrammes per cubic metre UKAS Uncertainty USA Validation (modelling) Validation (monitoring) Verification (modelling) Involves a critical review of all information relating to a data set, in order to amend or reject the data. When the data have been ratified they represent the final data to be used (see also validation). A length of road which is considered to have the same flow of traffic along it. Usually, a link is the road from one junction to the next. The value (e.g., of a concentration), which is entirely consistent with the definition of the units in which it is given. This is the value that would be obtained by a perfect measurement. A measure of concentration in terms of mass per unit volume. A concentration of 1ug/m 3 means that one cubic metre of air contains one microgram (millionth of a gram) of pollutant. United Kingdom Accreditation Service A measure, associated with the result of a measurement, which characterizes the range of values within which the true value is expected to lie. Uncertainty is usually expressed as the range within which the true value is expected to lie with a 95% probability, where standard statistical and other procedures have been used to evaluate this figure. Uncertainty is more clearly defined than the closely related parameter 'accuracy', and has replaced it on recent European legislation. Updating and Screening Assessment. Refers to the general comparison of modelled results against monitoring data carried out by model developers. Screening monitoring data by visual examination to check for spurious and unusual measurements (see also ratification). Comparison of modelled results versus any local monitoring data at relevant locations. Project number: Dated: 15/04/ Revised: 14/05/2014

47 Appendix B EU Limit Values and UK Objectives A summary of the current air quality objectives and EU limit values for the two pollutants of concern in the current assessment is provided below. Air Quality Objectives currently included in the Air Quality Standards Regulations 2010 Pollutant Nitrogen dioxide (NO 2) Applies to Concentration Standard Measured as Annual exceedences allowed Objective Target date All UK 200g/m 3 1 hour mean All UK 40g/m 3 annual mean /50/EC Particulate Matter (PM 10) 3 All UK 40µg/m (gravimetric) hour All UK 50g/m mean annual mean Explanation µg/m 3 = microgram per cubic metre; 1 Measured using the European gravimetric transfer sampler or equivalent. The Air Quality Strategy states that further review and assessment and consultation in relation to air quality will be a rolling process, with additional revisions to the objectives for selected pollutants as appropriate, or where there is new evidence in relation to the effects of pollutants on health or ecosystems. New pollutants may be introduced through future reviews

48 Appendix C Traffic Data Model Verification (2012) Link ID Road Link Speed (kph) Annual Average Daily Traffic Flow %HGVs NO x Emission Factors (g/s/km) PM 10 Emission Factors (g/s/km) 1_Ap1 A4 London Road - Carriageway Split A4 London Road - Btwn. Split and Hillrise _Ap2 A4 London Road - Junction 5 Roundabout _Ap 3_Ap1 3_Ap2 3 4_Ap 5_Ap 7_Ap 6_Ap A4 London Road - Eastbound Carriageway to Sutton Lane A4 London Road - Eastbound Carriageway Sutton Lane Intersection A4 Colnbrook By-Pass - Eastbound Carriageway (approaching merger) A4 Colnbrook By-Pass - Eastbound Carriageway (west of Application Site) A4 London Road Eastbound to Southbound Turning Movement A4 Colnbrook By-Pass Westbound to Southbound Turning Movement London Road Southbound to Westbound Turning Movement A4 London Road Southbound to Eastbound Turning Movement _Ap3 A4 Colnbrook By-Pass - Carriageway Merger b A4 Colnbrook By-Pass - Dual Carriageway _Ap London Road - Junction Approach south of Application Site London Road - South of Application Site _Ap1 9 9_Ap2 A4 London Road - Westbound Carriageway Towards Sutton Lane (Junction Departure) A4 London Road - Westbound Carriageway Towards Sutton Lane A4 London Road - Westbound Carriageway Towards Sutton Lane (Intersection) _Ap Sutton Lane (Slowed for Intersection) Sutton Lane _Ap London Road Westbound Turning Lane to A Project number: Dated: 15/04/ Revised: 14/05/2014

49 2014 Baseline Link ID Road Link Speed (kph) Annual Average Daily Traffic Flow %HGVs NO x Emission Factors (g/s/km) PM 10 Emission Factors (g/s/km) 1_Ap1 A4 London Road - Carriageway Split A4 London Road - Btwn. Split and Hillrise _Ap2 A4 London Road - Junction 5 Roundabout _Ap 3_Ap1 3_Ap2 3 4_Ap 5_Ap 7_Ap 6_Ap A4 London Road - Eastbound Carriageway to Sutton Lane A4 London Road - Eastbound Carriageway Sutton Lane Intersection A4 Colnbrook By-Pass - Eastbound Carriageway (approaching merger) A4 Colnbrook By-Pass - Eastbound Carriageway (west of Application Site) A4 London Road Eastbound to Southbound Turning Movement A4 Colnbrook By-Pass Westbound to Southbound Turning Movement London Road Southbound to Westbound Turning Movement A4 London Road Southbound to Eastbound Turning Movement _Ap3 A4 Colnbrook By-Pass - Carriageway Merger b A4 Colnbrook By-Pass - Dual Carriageway _Ap London Road - Junction Approach south of Application Site London Road - South of Application Site _Ap1 9 9_Ap2 A4 London Road - Westbound Carriageway Towards Sutton Lane (Junction Departure) A4 London Road - Westbound Carriageway Towards Sutton Lane A4 London Road - Westbound Carriageway Towards Sutton Lane (Intersection) _Ap Sutton Lane (Slowed for Intersection) Sutton Lane _Ap London Road Westbound Turning Lane to A

50 2019 Without Development / Do-Minimum Link ID Road Link Speed (kph) Annual Average Daily Traffic Flow %HGVs NO x Emission Factors (g/s/km) PM 10 Emission Factors (g/s/km) 1_Ap1 A4 London Road - Carriageway Split A4 London Road - Btwn. Split and Hillrise _Ap2 A4 London Road - Junction 5 Roundabout _Ap 3_Ap1 3_Ap2 3 4_Ap 5_Ap 7_Ap 6_Ap A4 London Road - Eastbound Carriageway to Sutton Lane A4 London Road - Eastbound Carriageway Sutton Lane Intersection A4 Colnbrook By-Pass - Eastbound Carriageway (approaching merger) A4 Colnbrook By-Pass - Eastbound Carriageway (west of Application Site) A4 London Road Eastbound to Southbound Turning Movement A4 Colnbrook By-Pass Westbound to Southbound Turning Movement London Road Southbound to Westbound Turning Movement A4 London Road Southbound to Eastbound Turning Movement _Ap3 A4 Colnbrook By-Pass - Carriageway Merger b A4 Colnbrook By-Pass - Dual Carriageway _Ap London Road - Junction Approach south of Application Site London Road - South of Application Site _Ap1 9 9_Ap2 A4 London Road - Westbound Carriageway Towards Sutton Lane (Junction Departure) A4 London Road - Westbound Carriageway Towards Sutton Lane A4 London Road - Westbound Carriageway Towards Sutton Lane (Intersection) _Ap Sutton Lane (Slowed for Intersection) Sutton Lane _Ap London Road Westbound Turning Lane to A Project number: Dated: 15/04/ Revised: 14/05/2014

51 2019 With Development / Do-Something Link ID Road Link Speed (kph) Annual Average Daily Traffic Flow %HGVs NO x Emission Factors (g/s/km) PM 10 Emission Factors (g/s/km) 1_Ap1 A4 London Road - Carriageway Split A4 London Road - Btwn. Split and Hillrise _Ap2 A4 London Road - Junction 5 Roundabout _Ap 3_Ap1 3_Ap2 3 4_Ap 5_Ap 7_Ap 6_Ap A4 London Road - Eastbound Carriageway to Sutton Lane A4 London Road - Eastbound Carriageway Sutton Lane Intersection A4 Colnbrook By-Pass - Eastbound Carriageway (approaching merger) A4 Colnbrook By-Pass - Eastbound Carriageway (west of Application Site) A4 London Road Eastbound to Southbound Turning Movement A4 Colnbrook By-Pass Westbound to Southbound Turning Movement London Road Southbound to Westbound Turning Movement A4 London Road Southbound to Eastbound Turning Movement _Ap3 A4 Colnbrook By-Pass - Carriageway Merger b A4 Colnbrook By-Pass - Dual Carriageway _Ap London Road - Junction Approach south of Application Site London Road - South of Application Site _Ap1 9 9_Ap2 A4 London Road - Westbound Carriageway Towards Sutton Lane (Junction Departure) A4 London Road - Westbound Carriageway Towards Sutton Lane A4 London Road - Westbound Carriageway Towards Sutton Lane (Intersection) _Ap Sutton Lane (Slowed for Intersection) Sutton Lane _Ap London Road Westbound Turning Lane to A

52 Appendix D Summary of IAQM Construction Phase Impact Assessment Procedure Step 1 Screening the need for a Detailed Assessment An assessment will normally be required where there is: A human receptor within: - 350m of the boundary of the site; or - 50m of the route(s) used by construction vehicles on the public highway, up to 500m from the site entrance(s). An ecological receptor within: - 50m of the boundary of the site; or - 50m of the route(s) used by construction vehicles on the public highway, up to 500m from the site entrance(s). Where the need for a more detailed assessment is screened out, it can be concluded that the level of risk is negligible and any effect will not be significant. Step 2 Assess the Risk of Dust Impacts Arising The risk of dust arising in sufficient quantities to cause annoyance and/or health and/or ecological impacts should be determined using four risk categories: negligible, low, medium and high risk. A site is allocated to a risk category based on two factors: The scale and nature of the works, which determines the potential dust e mission magnitude as small, medium or large (Step 2A); and The sensitivity of the area to dust impacts (Step 2B), which is defined as low medium or high sensitivity. These two factors are combined in Step 2C to determine the risk of dust impacts with no mitigation applied. The risk category assigned to the site can be different for each of the four potential activities (demolition, earthworks, construction and trackout). Step 2A Define the Potential Dust Emission Magnitude The dust emission magnitude is based on the scale of the anticipated works and should be classified as Small, Medium or Large. The following are examples of how the potential dust emission magnitude for different activities can be defined. Note that in each case, not all the criteria need to be met, and that other criteria may be used if justified in the assessment. 1) Demolition Example definitions for demolition are: Large: Total building volume >50,000 m 3 potentially dusty construction material (e.g. concrete), on-site crushing and screening, demolition activities >20m above ground level; Medium: Total building volume 20,000m 3 50,000m 3, potentially dusty construction material, demolition activities m above ground level; and Project number: Dated: 15/04/ Revised: 14/05/2014

53 Small: Total building volume <20,000m 3, construction material with low potential for dust release (e.g. metal cladding or timber), demolition activities <10m above ground, demolition during wetter months. 2) Earthworks Earthworks will primarily involve excavating material, haulage, tipping and stockpiling. This may also involve levelling the site and landscaping. Example definitions for earthworks are: Large: Total site area >10,000m 2, potentially dusty soil type (e.g. clay, which will be prone to suspension when dry due to small particle size), >10 heavy earth moving vehicles active at any one time, formation of bunds >8 m in height, total material moved >100,000 tonnes; Medium: Total site area 2,500 m 2 10,000 m 2, moderately dusty soil type (e.g. silt), 5-10 heavy earth moving vehicles active at any one time, formation of bunds 4 m - 8 m in height, total material moved 20,000 tonnes 100,000 tonnes; and, Small: Total site area <2,500 m 2, soil type with large grain size (e.g. sand), <5 heavy earth moving vehicles active at any one time, formation of bunds <4 m in height, total material moved <10,000 tonnes, earthworks during wetter months. 3) Construction The key issues when determining the potential dust emission magnitude during the construction phase include the size of the building(s)/infrastructure, method of construction, construction materials and duration of build. Example definitions for construction are: Large: Total building volume >100,000 m 3, piling, on site concrete batching, sandblasting Medium: Total building volume 25,000 m 3 100,000 m 3, potentially dusty construction material (e.g. concrete), piling, on site concrete batching; and Small: Total building volume <25,000 m 3, construction material with low potential for dust release (e.g. metal cladding or timber). 4) Trackout Factors which determine the magnitude class are vehicle size, vehicle speed, vehicle numbers, geology and duration. As with all other potential sources, professional judgement must be applied when classifying trackout into one of the magnitude categories. Example definitions of trackout are: Large: >50 HDV (>3.5t) outward vehicle movements in any one day, potentially dusty surface material (e.g. high clay content), unpaved road length >100m; Medium: HDV (>3.5t) outward vehicle movements in any one day, moderately dusty surface material (e.g. high clay content), unpaved road length 50m 100m; and Small / Medium: <10 HDV (>3.5t) outward vehicle movements in any one day, surface material with low potential for dust release, unpaved road length <50m. These numbers are for vehicles that leave the site after moving over unpaved ground, where they will accumulate mud and dirt that can be tracked out onto the public highway

54 Step 2B Define the sensitivity of the area The guidance to identify the sensitivity of different types of receptor to Dust Soiling, Health Effects and Ecological Effects are listed Tables D1 to D3 below: Table D1: Sensitivity of People to Dust Soiling Effects High Sensitivity Receptor users can reasonably expect enjoyment of a high level of amenity; or the appearance, aesthetics or value of their property would be diminished by soiling; and the people or property would reasonably be expected to be present continuously, or at least regularly for extended periods, as part of the normal pattern of use of the land. indicative examples include dwellings, museums and other culturally important collections, medium and long term car parks and car showrooms. Medium Sensitivity Receptor users would expect to enjoy a reasonable level of amenity, but would not reasonably expect to enjoy the same level of amenity as in their home; or the appearance, aesthetics or value of their property could be diminished by soiling; or the people or property wouldn t reasonably be expected to be present here continuously or regularly for extended periods as part of the normal pattern of use of the land. indicative examples include parks and places of work. Low Sensitivity Receptor the enjoyment of amenity would not reasonably be expected; or property would not reasonably be expected to be diminished in appearance, aesthetics or value by soiling; or there is transient exposure, where the people or property would reasonably be expected to be present only for limited periods of time as part of the normal pattern of use of the land. indicative examples include playing fields, farmland (unless commercially-sensitive horticultural), footpaths, short term car parks and roads. Table D2: Sensitivity of People to Health Effects of PM 10 High Sensitivity Receptor locations where members of the public are exposed over a time period relevant to the air quality objective for PM 10 (in the case of the 24-hour objectives, a relevant location would be one where individuals may be exposed for eight hours or more in a day). Indicative examples include residential properties. Hospitals, schools and residential care homes should also be considered as having equal sensitivity to residential areas for the purposes of this assessment. Medium Sensitivity Receptor locations where the people exposed are workers, and exposure is over a time period relevant to the air quality objective for PM 10 (in the case of the 24-hour objectives, a relevant location would be one where individuals may be exposed for eight hours or more in a day). indicative examples include office and shop workers, but will generally not include workers occupationally exposed to PM 10, as protection is covered by Health and Safety at Work legislation. Low Sensitivity Receptor locations where human exposure is transient. indicative examples include public footpaths, playing fields, parks and shopping streets. Project number: Dated: 15/04/ Revised: 14/05/2014

55 Table D3: Sensitivity of Ecological Effects High Sensitivity Receptor locations with an international or national designation and the designated features may be affected by dust soiling; or locations where there is a community of a particularly dust sensitive species such as vascular species included in the Red Data List For Great Britain. indicative examples include a Special Area of Conservation (SAC) designated for acid heathlands or a local site designated for lichens adjacent to the demolition of a large site containing concrete (alkali) buildings. Medium Sensitivity Receptor locations where there is a particularly important plant species, where its dust sensitivity is uncertain or unknown; or locations with a national designation where the features may be affected by dust deposition. indicative example is a Site of Special Scientific Interest (SSSI) with dust sensitive features. Low Sensitivity Receptor locations with a local designation where the features may be affected by dust deposition. indicative example is a local Nature Reserve with dust sensitive features. Tables D4 to D6 below present the how the sensitivity of the area can be determined for dust soiling, human health and ecological impacts respectively. The sensitivity of the area should be determined for each of the four activities: demolition, construction, earthworks and trackout. Only the highest level of area sensitivity from the tables need to be considered; it is not necessary to work through the whole of each table once it is clear that the highest level of sensitivity has been determined. Whilst these tables are necessarily prescriptive, professional judgement may be used to determine alternative sensitivity categories see full IAQM Construction Dust Guidance (2014) for further details. Table D4: Sensitivity of the Area to Dust Soiling Effects Receptor Sensitivity Number of Receptors Distance from the Source (m) <20 <50 <100 <350 High >100 High High Medium Low High Medium Low Low 1-10 Medium Low Low Low Medium >1 Medium Low Low Low Low >1 Low Low Low Low 55 78

56 Table D5: Sensitivity of the Area to Human Health Impacts Receptor Sensitivity Annual Mean PM 10 Concentration, µg/m 3 Number of Receptors Distance from the Source (m) <20 <50 <100 <200 <350 High >32 >100 High High High Medium Low High High Medium Low Low 1-10 High Medium Low Low Low >100 High High Medium Low Low High Medium Low Low Low 1-10 High Medium Low Low Low >100 High Medium Low Low Low High Medium Low Low Low 1-10 Medium Low Low Low Low <24 >100 Medium Low Low Low Low Low Low Low Low Low 1-10 Low Low Low Low Low Medium - >10 High Medium Low Low Low 1-10 Medium Low Low Low Low Low - >10 Low Low Low Low Low Low Low Low Low Low Table D6: Sensitivity of the Area to Ecological Impacts Receptor Sensitivity Distance from the Sources (m) <20 <50 High High Medium Medium Medium Low Low Low Low Step 2C Define the Risk of Impacts The potential dust emission class determined above in Step 2A should be combined with the sensitivity of the area determined in Step 2B to determine the risk of impacts. Tables D7 to D9 provide matrices to determine the risk of impacts. Table D7: Risk Category from Demolition Activities Sensitivity of Area Dust Emission Magnitude Large Medium Small High High Risk Medium Risk Medium Risk Medium High Risk Medium Risk Low Risk Low Medium Risk Low Risk Negligible Project number: Dated: 15/04/ Revised: 14/05/2014

57 Table D8: Risk Category from Earthworks & Construction Activities Sensitivity of Area Dust Emission Magnitude Large Medium Small High High Risk Medium Risk Low Risk Medium Medium Risk Medium Risk Low Risk Low Low Risk Low Risk Negligible Table D9: Risk Category from Trackout Sensitivity of Area Dust Emission Magnitude Large Medium Small High High Risk Medium Risk Low Risk Medium Medium Risk Low Risk Low Risk Low Low Risk Low Risk Negligible There is an extra dimension to the assessment of trackout, as the distance over which it might occur depends on the site. As general guidance, significant trackout may occur up to 500m from large sites, 200m from medium sites and 50m from small sites, as measured from the site exit. These distances assume no sitespecific mitigation. Step 3 Identify the need for Site Specific Mitigation Having determined the risk categories for each of the four activities it is possible to determine the site-specific measures to be adopted. These measures will be related to whether the site is a low, medium or high risk site. Tables D10 to D15 provide the general mitigation measures and those required for high, medium and low risk for each of the four activities

58 Project number: Dated: 15/04/ Revised: 14/05/2014 Table D10: Mitigation for all sites: Communications Mitigation measure Low Risk Medium Risk High Risk 1. Develop and implement a stakeholder communications plan that includes community engagement before work commences on site. N H H 2. Display the name and contact details of person(s) accountable for air quality and dust issues on the site boundary. This may be the environment manager/engineer or the site manager. H H H 3. Display the head or regional office contact information H H H Table D11: Mitigation for all sites: Dust Management Mitigation measure Low Risk Medium Risk High Risk 4. Develop and implement a Dust Management Plan (DMP), which may include measures to control other emissions, approved by the Local Authority. The level of detail will depend on the risk, and should include as a minimum the highly recommended measures in this document. The desirable measures should be included as appropriate for the site. In London additional measures may be required to ensure compliance with the Mayor of London s guidance. The DMP may include monitoring of dust deposition, dust flux, real-time PM 10 continuous monitoring and/or visual inspections. D H H Site Management 5. Record all dust and air quality complaints, identify cause(s), take appropriate measures to reduce emissions in a timely manner, and record the measures taken. H H H 6. Make the complaints log available to the local authority when asked. H H H 7. Record any exceptional incidents that cause dust and/or air emissions, either on- or offsite, and the action taken to resolve the situation in the log book. 8. Hold regular liaison meetings with other high risk construction sites within 500m of the site boundary, to ensure plans are co-ordinated and dust and particulate matter emissions are minimised. It is important to understand the interactions of the off-site transport/ deliveries which might be using the same strategic road network routes. H H H N N H Monitoring 9. Undertake daily on-site and off-site inspection, where receptors (including roads) are nearby, to monitor dust, record inspection results, and make the log available to the local authority when asked. This should include regular dust soiling checks of surfaces such as street furniture, cars and window sills within 100m of site boundary, with cleaning to be provided if necessary. D D H

59 Mitigation measure Low Risk Medium Risk High Risk 10. Carry out regular site inspections to monitor compliance with the DMP, record inspection results, and make an inspection log available to the local authority when asked 11. Increase the frequency of site inspections by the person accountable for air quality and dust issues on site when activities with a high potential to produce dust are being carried out and during prolonged dry or windy conditions. 12. Agree dust deposition, dust flux, or real-time PM 10 continuous monitoring locations with the Local Authority. Where possible commence baseline monitoring at least three months before work commences on site or, if it a large site, before work on a phase commences. Further guidance is provided by IAQM on monitoring during demolition, earthworks and construction. H H H H H H N H H Preparing and maintaining the site 13. Plan site layout so that machinery and dust causing activities are located away from receptors, as far as is possible. H H H 14. Erect solid screens or barriers around dusty activities or the site boundary that are at least as high as any stockpiles on site. H H H 15. Fully enclose site or specific operations where there is a high potential for dust production and the site is actives for an extensive period D H H 16. Avoid site runoff of water or mud. H H H 17. Keep site fencing, barriers and scaffolding clean using wet methods. D H H 18. Remove materials that have a potential to produce dust from site as soon as possible, unless being re-used on site. If they are being reused on-site cover as described below. D H H 19. Cover, seed or fence stockpiles to prevent wind whipping. D H H Operating vehicle/machinery and sustainable travel 20. Ensure all on-road vehicles comply with the requirements of the London Low Emission Zone and the London NRMM standards, where applicable H H H 21. Ensure all vehicles switch off engines when stationary - no idling vehicles. H H H 22. Avoid the use of diesel or petrol powered generators and use mains electricity or battery powered equipment where practicable. H H H 23. Impose and signpost a maximum-speed-limit of 15 mph on surfaced and 10 mph on unsurfaced haul roads and work areas (if long haul routes are required these speeds may be increased with suitable additional control measures provided, subject to the approval of the nominated undertaker and with the agreement of the local authority, where appropriate) D D H 59 78

60 Project number: Dated: 15/04/ Revised: 14/05/2014 Mitigation measure Low Risk Medium Risk High Risk 24. Produce a Construction Logistics Plan to manage the sustainable delivery of goods and materials. N H H 25. Implement a Travel Plan that supports and encourages sustainable travel (public transport, cycling, walking, and car-sharing) N D H Operations 26. Only use cutting, grinding or sawing equipment fitted or in conjunction with suitable dust suppression techniques such as water sprays or local extraction, e.g. suitable local exhaust ventilation systems. 27. Ensure an adequate water supply on the site for effective dust/particulate matter suppression/mitigation, using non-potable water where possible and appropriate. H H H H H H 28. Use enclosed chutes and conveyors and covered skips. H H H 29. Minimise drop heights from conveyors, loading shovels, hoppers and other loading or handling equipment and use fine water sprays on such equipment wherever appropriate. 30. Ensure equipment is readily available on site to clean any dry spillages, and clean up spillages as soon as reasonably practicable after the event using wet cleaning methods. H H H D H H Waste management 31. Avoid bonfires and burning of waste materials. H H H Table D12: Mitigation specific to demolition Mitigation measure Low Risk Medium Risk High Risk 32. Soft strip inside buildings before demolition (retaining walls and windows in the rest of the building where possible, to provide a screen against dust). 33. Ensure effective water suppression is used during demolition operations. Hand held sprays are more effective than hoses attached to equipment as the water can be directed to where it is needed. In addition high volume water suppression systems, manually controlled, can produce fine water droplets that effectively bring the dust particles to the ground. D D H H H H 34. Avoid explosive blasting, using appropriate manual or mechanical alternatives. H H H 35. Bag and remove any biological debris or damp down such material before demolition. H H H

61 Table D13: Mitigation specific to earthworks Mitigation measure Low Risk Medium Risk High Risk 36. Re-vegetate earthworks and exposed areas/soil stockpiles to stabilise surfaces as soon as practicable. N D H 37. Use Hessian, mulches or trackifiers where it is not possible to re-vegetate or cover with topsoil, as soon as practicable N D H 38. Only remove the cover in small areas during work and not all at once N D H Table D14: Mitigation specific to construction Mitigation measure Low Risk Medium Risk High Risk 39. Avoid scabbling (roughening of concrete surfaces) if possible D D H 40. Ensure sand and other aggregates are stored in bunded areas and are not allowed to dry out, unless this is required for a particular process, in which case ensure that appropriate additional control measures are in place. 41. Ensure bulk cement and other fine powder materials are delivered in enclosed tankers and stored in silos with suitable emission control systems to prevent escape of material and overfilling during delivery. D H H N D H 42. For smaller supplies of fine power materials ensure bags are sealed after use and stored appropriately to prevent dust. N D D Table D15: Mitigation specific to trackout Mitigation measure Low Risk Medium Risk High Risk 43. Use water-assisted dust sweeper(s) on the access and local roads, to remove, as necessary, any material tracked out of the site. This may require the sweeper being continuously in use. D H H 44. Avoid dry sweeping of large areas. D H H 45. Ensure vehicles entering and leaving sites are covered to prevent escape of materials during transport. D H H 46. Inspect on-site haul routes for integrity and instigate necessary repairs to the surface as soon as reasonably practicable. N H H 47. Record all inspections of haul routes and any subsequent action in a site log book. D H H 48. Install hard surfaced haul routes, which are regularly damped down with fixed or mobile sprinkler systems, or mobile water bowsers and regularly cleaned. N H H 61 78

62 Project number: Dated: 15/04/ Revised: 14/05/2014 Mitigation measure Low Risk Medium Risk High Risk 49. Implement a wheel washing system (with rumble grids to dislodge accumulated dust and mud prior to leaving the site where reasonably practicable). 50. Ensure there is an adequate area of hard surfaced road between the wheel wash facility and the site exit, wherever site size and layout permits D H H N H H 51. Access gates to be located at least 10m from receptors where possible. N H H

63 Step 4 Determine Significant Impacts The significance is best determined using professional judgement, taking account of the factors that define the sensitivity of the surrounding area and the overall pattern of potential risks. The sensitivity of the area needs to be defined. The sensitivity of the area surrounding the construction / demolition site is combined with the risk of the site giving rise to dust impacts (from Step 2) to define the significance of the impacts for each of the four activities (demolition, earthworks, construction and trackout). The preference in the IAQM Guidance is to only assign significance to the impact with mitigation. The residual impacts for most sites will be negligible

64 Appendix E Model Verification Calculations The comparison of modelled concentrations with local monitored concentrations is a process termed verification. Model verification investigates the discrepancies between modelled and measured concentrations, which can arise due to the presence of inaccuracies and/or uncertainties in model input data, modelling and monitoring data assumptions. The following are examples of potential causes of such discrepancy: a) estimates of background pollutant concentrations; b) meteorological data uncertainties; c) traffic data uncertainties; d) model input parameters, such as roughness length ; and e) overall limitations of the dispersion model. Model Precision Residual uncertainty may remain after systematic error or model accuracy has been accounted for in the final predictions. Residual uncertainty may be considered synonymous with the precision of the model predictions, i.e. how wide the scatter or residual variability of the predicted values compare with the monitored true value, once systematic error has been allowed for. The quantification of model precision provides an estimate of how the final predictions may deviate from true (monitored) values at the same location over the same period. Suitable local monitoring data for the purpose of verification is available for concentrations of NO 2 at the locations described in Section 3. This monitoring data have been used to validate the dispersion model prediction and obtain adjustment factors which can be applied to predictions of pollutant concentrations in the base and future years. NO x adjustment factors were used as a proxy to adjust the PM 10 output as no monitoring of PM has been undertaken close to the site. Model Performance An evaluation of model performance has been undertaken to establish confidence in model results. LAQM.TG(09) identifies a number of statistical procedures that are appropriate to evaluate model performance and assess the uncertainty. The statistical parameters used in this assessment are: a) root mean square error (RMSE); b) fractional bias (FB); and c) correlation coefficient (CC). A brief for explanation of each statistic is provided in Table E1, and further details can be found in LAQM.TG(09) Box A3.7. It can be seen that the model performance was good after adjustment. Project number: Dated: 15/04/ Revised: 14/05/2014

65 Table E1 - Model Performance Statistics Statistical Parameter Comments Ideal value Value achieved RMSE is used to define the average error or uncertainty of the model. The units of RMSE are the same as the quantities compared. RMSE If the RMSE values are higher than 25% of the objective being assessed, it is recommended that the model inputs and verification should be revisited in order to make improvements. For example, if the model predictions are for the annual mean NO 2 objective of 40g/m 3, if an RMSE of 10g/m 3 or above is determined for a model it is advised to revisit the model parameters and model verification. Ideally an RMSE within 10% of the air quality objective would be derived, which equates to 4g/m 3 for the annual mean NO 2 objective Fractional Bias Correlation Coefficient It is used to identify if the model shows a systematic tendency to over or under predict. FB values vary between +2 and -2 and has an ideal value of zero. Negative values suggest a model over-prediction and positive values suggest a model under-prediction. It is used to measure the linear relationship between predicted and observed data. A value of zero means no relationship and a value of 1 means absolute relationship. This statistic can be particularly useful when comparing a large number of model and observed data points These parameters estimate how the model results agree or diverge from the observations. These calculations have been carried out prior to, and after, adjustment and provide information on the improvement of the model predictions as a result of the application of the verification adjustment factors. Assessment Verification Methodology The model outputs of road-no x (i.e. the component of total NO x coming from road traffic) were compared with the measured road-no x at the diffusion tube locations. A one stage model Verification process was applied in order to suitably correct any under or over estimations in the model, developing the method set out by Defra (2009) and taking into account the most recent guidance. Total measured NO x was calculated from the measured NO 2 concentrations at the monitoring locations using the recently updated NO x from NO 2 calculator available on the Defra website. The measured road-no x contribution was then calculated as the difference between the total and the background value. The NO x roads adjustment factor was determined as the multiplier between the calculated (measured) road contribution and the model derived road contribution. Detail of the verification process data is presented in Table E2. The adjustment factor (2.6) was applied to all modelled results and is presented in Table E

66 Table E2 Verification Process Data Site ID Monitored Total NO 2 Background NO 2 Monitored NO 2 Contribution Monitored Road Contribution NO x Modelled Road Contribution NO x Brands Hill (B) London Road (B) London Road (C) Table E3 Adjustment Factor Site ID Ratio of monitored NO x road contribution /modelled road contribution NO x Adjustment factor for modelled road contribution Adjusted modelled road contribution NO x Modelled Total NO 2 Monitored Total NO 2 % Difference Brands Hill (B) London Road (B) London Road (C) Total Monitored NO Modelled NO2 vs Monitored NO2 1st Adjustment Series1 y=x Model Overestimation of 25% Model Underestimatio n of 25% Total Modelled NO2 Project number: Dated: 15/04/ Revised: 14/05/2014

67 Appendix F Summary of EPUK Assessment Significance Criteria The following criteria relate to changes in annual mean NO 2 /PM 10 concentrations and 24-hour mean PM 10 concentrations resulting from the development. ANNUAL MEAN NO 2 AND PM 10 CONCENTRATIONS SIGNIFICANCE CRITERIA DEFINITION NEUTRAL NEGLIGIBLE IMPACT A SLIGHT ADVERSE IMPACT A MODERATE ADVERSE IMPACT A SUBSTANTIAL ADVERSE IMPACT A SLIGHT BENEFICIAL IMPACT A MODERATE BENEFICIAL IMPACT A SUBSTANTIAL BENEFICIAL IMPACT The development causes no change in concentrations. The development gives rise to a IMPERCEPTIBLE change in concentrations or; The development gives rise to a SMALL change in concentrations and predicted concentrations are below 36µg/m 3 ; or The development gives rise to a MEDIUM change in concentrations and predicted concentrations are below 30µg/m 3. The development gives rise to a SMALL increase in concentrations and predicted concentrations with the development in place are above 36µg/m 3 ; or The development gives rise to a MEDIUM increase in concentrations and predicted concentrations with the development in place are between 30-36µg/m 3 ; or The development gives rise to a LARGE increase in concentrations and predicted concentrations with the development in place are less than 36µg/m 3. The development gives rise to a MEDIUM increase in concentrations and predicted concentrations with the development in place are above 36µg/m 3 ; or The development gives rise to a LARGE increase in concentrations and predicted concentrations with the development in place are between 36-40µg/m 3. The development gives rise to a LARGE increase in concentrations and predicted concentrations with the development in place exceed the objective level of 40µg/m 3. The development gives rise to a SMALL decrease in concentrations and predicted concentrations without the development in place are above 36µg/m 3 ; or The development gives rise to a MEDIUM decrease in concentrations and predicted concentrations without the development in place are between 30-36µg/m 3 ; or The development gives rise to a LARGE decrease in concentrations and predicted concentrations without the development in place are less than 36µg/m 3. The development gives rise to a MEDIUM decrease in concentrations and predicted concentrations without the development in place are above 36µg/m 3 ; or The development gives rise to a LARGE decrease in concentrations and predicted concentrations without the development in place are between 36-40µg/m 3. The development gives rise to a LARGE decrease in concentrations and predicted concentrations without the development in place exceed the objective level of 40µg/m 3. Where the magnitude of change in concentration for annual mean NO 2 and PM 10 has been defined as follows: An IMPERCEPTIBLE change is a change of <0.4µg/m 3 ; A SMALL change is a change of less than 0.4 2µg/m 3 ; A MEDIUM change is a change of 2-4µg/m 3 ; and A LARGE change is a change of > 4µg/m

68 DAILY MEAN PM 10 CONCENTRATIONS SIGNIFICANCE CRITERIA DEFINITION NEUTRAL NEGLIGIBLE IMPACT A SLIGHT ADVERSE IMPACT A MODERATE ADVERSE IMPACT A SUBSTANTIAL ADVERSE IMPACT A SLIGHT BENEFICIAL IMPACT A MODERATE BENEFICIAL IMPACT A SUBSTANTIAL BENEFICIAL IMPACT The development causes no change in the number of days of exceedence. The development gives rise to a IMPERCEPTIBLE change in the number of days of exceedence; or The development gives rise to a SMALL change and the predicted number of days of exceedence is below 32 days; or The development gives rise to a MEDIUM change and the predicted number of days of exceedence is below 26 days. The development gives rise to a SMALL increase and the predicted number of days of exceedence is above 32 days; or The development gives rise to a MEDIUM increase and the predicted number of days of exceedence is between 26 and 32 days; or The development gives rise to a LARGE increase and the predicted number of days of exceedence is below 32 days. The development gives rise to a MEDIUM increase and the predicted number of days of exceedence is above 32 days; or The development gives rise to a LARGE increase and the predicted number of days of exceedence is between 32 and 35 days. The development gives rise to a LARGE increase and the number of days of exceedence with the development in place is above 35 days. The development gives rise to a SMALL decrease and the predicted number of days of exceedence without the development is above 32 days; or The development gives rise to a MEDIUM decrease and the predicted number of days of exceedence without the development is between 26 and 32 days; or The development gives rise to a LARGE decrease and the predicted number of days of exceedence without the development is between 32 and 35 days. The development gives rise to a MEDIUM decrease and the predicted number of days of exceedence without the development is above 32 days; or The development gives rise to a LARGE decrease and the predicted number of days of exceedence without the development is between 32 and 35 days. The development gives rise to a LARGE decrease and the number of days of exceedence without the development in place is above 35 days. Where the magnitude of change is defined as the number of days of exceedence of a daily mean PM 10 concentration of 50µg/m 3 : An IMPERCEPTIBLE change is a change of < 1 day; A SMALL change is a change of 1-2 days; A MEDIUM change is a change of 2-4 days; and A LARGE change is a change of > 4 days. Project number: Dated: 15/04/ Revised: 14/05/2014

69 Appendix G Assessment Results OPERATION PHASE NO 2 Annual Mean Results NO 2 Annual Mean 2005 Source AQS Objective (µg/m 3 ) 40 UK Air Quality Standards Regs 2010 Receptor Number Receptor Name/Description Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - Springfirld Road Existing Residential Receptor - London Road Existing Residential Receptor - Sutton Place Existing Residential Receptor - Disraeli Court New Exposure - Ground Floor (Northwest Corner Block A) New Exposure - 1st Floor (Northwest Corner Block A) New Exposure - 2nd Floor (Northwest Corner Block A) New Exposure - 3rd Floor (Northwest Corner Block A) New Exposure - 4th Floor (Northwest Corner Block A) New Exposure - Ground Floor (Northeast Corner Block C) New Exposure - 1st Floor (Northeast Corner Block C) New Exposure - 2nd Floor (Northeast Corner Block C) New Exposure - 3rd Floor (Northeast Corner Block C) New Exposure - 4th Floor (Northeast Corner Block C) New Exposure - Ground Floor (East Boundary) Baseline Do Minimum (Excl. Proposed Development) Do Something (Incl. Proposed Development) Change (DM-DS) APEC-C APEC-C APEC-B APEC-A APEC-A APEC-C APEC-C APEC-B APEC-A APEC-A APEC-B 69 78

70 New Exposure - 1st Floor (East Boundary) New Exposure - 2nd Floor (East Boundary) New Exposure - 3rd Floor (East Boundary) New Exposure - 4th Floor (East Boundary) New Exposure - Ground Floor (South Corner Block B) New Exposure - 1st Floor (South Corner Block B) New Exposure - 2nd Floor (South Corner Block B) New Exposure - 3rd Floor (South Corner Block B) New Exposure - 4th Floor (South Corner Block B) New Exposure - Ground Floor (Southeast Corner Block A) New Exposure - 1st Floor (Southeast Corner Block A) New Exposure - 2nd Floor (Southeast Corner Block A) New Exposure - 3rd Floor (Southeast Corner Block A) New Exposure - 4th Floor (Southeast Corner Block A) New Exposure - Ground Floor (West Corner Block A) New Exposure - 1st Floor (West Corner Block A) New Exposure - 2nd Floor (West Corner Block A) New Exposure - 3rd Floor (West Corner Block A) New Exposure - 4th Floor (West Corner Block A) APEC-B APEC-A APEC-A APEC-A APEC-B APEC-B APEC-A APEC-A APEC-A APEC-C APEC-B APEC-B APEC-A APEC-A APEC-C APEC-C APEC-B APEC-A APEC-A Project number: Dated: 15/04/ Revised: 14/05/2014

71 OPERATION PHASE PM 10 Annual Mean Results PM 10 annual mean ug/m 3 Source Objective (ug/m 3 ) AQS 2007 Receptor Number Receptor Name/Description Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - Springfirld Road Existing Residential Receptor - London Road Existing Residential Receptor - Sutton Place Existing Residential Receptor - Disraeli Court New Exposure - Ground Floor (Northwest Corner Block A) New Exposure - 1st Floor (Northwest Corner Block A) New Exposure - 2nd Floor (Northwest Corner Block A) New Exposure - 3rd Floor (Northwest Corner Block A) New Exposure - 4th Floor (Northwest Corner Block A) New Exposure - Ground Floor (Northeast Corner Block C) New Exposure - 1st Floor (Northeast Corner Block C) New Exposure - 2nd Floor (Northeast Corner Block C) New Exposure - 3rd Floor (Northeast Corner Block C) New Exposure - 4th Floor (Northeast Corner Block C) New Exposure - Ground Floor (East Boundary) New Exposure - 1st Floor (East Boundary) New Exposure - 2nd Floor (East Boundary) New Exposure - 3rd Floor (East Boundary) Baseline Do Minimum (Excl. Proposed Development) Do Something (Incl. Proposed Development) Change (DM-DS) APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A 71 78

72 New Exposure - 4th Floor (East Boundary) New Exposure - Ground Floor (South Corner Block B) New Exposure - 1st Floor (South Corner Block B) New Exposure - 2nd Floor (South Corner Block B) New Exposure - 3rd Floor (South Corner Block B) New Exposure - 4th Floor (South Corner Block B) New Exposure - Ground Floor (Southeast Corner Block A) New Exposure - 1st Floor (Southeast Corner Block A) New Exposure - 2nd Floor (Southeast Corner Block A) New Exposure - 3rd Floor (Southeast Corner Block A) New Exposure - 4th Floor (Southeast Corner Block A) New Exposure - Ground Floor (West Corner Block A) New Exposure - 1st Floor (West Corner Block A) New Exposure - 2nd Floor (West Corner Block A) New Exposure - 3rd Floor (West Corner Block A) New Exposure - 4th Floor (West Corner Block A) APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A Project number: Dated: 15/04/ Revised: 14/05/2014

73 OPERATION PHASE PM Hour (Daily) Mean Results PM Hour (Daily) Mean 2004 Source AQS Objective (µg/m 3 ) 50 (not to be exceeded more than 35 times per year) UK Air Quality Standards Regs 2010 Receptor Number Receptor Name/Description Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - London Road Existing Residential Receptor - Springfirld Road Existing Residential Receptor - London Road Existing Residential Receptor - Sutton Place Existing Residential Receptor - Disraeli Court New Exposure - Ground Floor (Northwest Corner Block A) New Exposure - 1st Floor (Northwest Corner Block A) New Exposure - 2nd Floor (Northwest Corner Block A) New Exposure - 3rd Floor (Northwest Corner Block A) New Exposure - 4th Floor (Northwest Corner Block A) New Exposure - Ground Floor (Northeast Corner Block C) New Exposure - 1st Floor (Northeast Corner Block C) New Exposure - 2nd Floor (Northeast Corner Block C) New Exposure - 3rd Floor (Northeast Corner Block C) New Exposure - 4th Floor (Northeast Corner Block C) New Exposure - Ground Floor (East Boundary) New Exposure - 1st Floor (East Boundary) New Exposure - 2nd Floor (East Boundary) Baseline Do Minimum (Excl. Proposed Development) Do Something (Incl. Proposed Development) Change (DM-DS) No Change No Change No Change No Change No Change No Change No Change No Change No Change APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A 73 78

74 New Exposure - 3rd Floor (East Boundary) New Exposure - 4th Floor (East Boundary) New Exposure - Ground Floor (South Corner Block B) New Exposure - 1st Floor (South Corner Block B) New Exposure - 2nd Floor (South Corner Block B) New Exposure - 3rd Floor (South Corner Block B) New Exposure - 4th Floor (South Corner Block B) New Exposure - Ground Floor (Southeast Corner Block A) New Exposure - 1st Floor (Southeast Corner Block A) New Exposure - 2nd Floor (Southeast Corner Block A) New Exposure - 3rd Floor (Southeast Corner Block A) New Exposure - 4th Floor (Southeast Corner Block A) New Exposure - Ground Floor (West Corner Block A) New Exposure - 1st Floor (West Corner Block A) New Exposure - 2nd Floor (West Corner Block A) New Exposure - 3rd Floor (West Corner Block A) New Exposure - 4th Floor (West Corner Block A) APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A APEC-A Project number: Dated: 15/04/ Revised: 14/05/2014

75 File: Drawn By: BR Date Modified: 02/04/2014!( 1 Contains Ordnance Survey data Crown copyright and database right 2014.!( 3!( Kilometres!( 9!(!( 8 4!( 5!(!( !(!( 25!( 20!( 15!(!( 7 6 KEY Application Site Modelled Roads!( Existing Receptors!( New Exposure Receptors AQMA Boundary TITLE: HEATHROW GATEWAY AIR QUALITY ASSESSMENT APPLICATION SITE, MODELLED ROADS AND RECEPTORS FIGURE No: FIGURE 1

76 File: Drawn By: BR Date Modified: 02/04/2014 Contains Ordnance Survey data Crown copyright and database right London Road (C) $ Kilometres $+ London Road (B) $+ Brands Hill (B) TITLE: KEY HEATHROW GATEWAY AIR QUALITY ASSESSMENT VERIFICATION SITES FIGURE No: Application Site Modelled Roads $+ Verification Sites AQMA Boundary FIGURE 2

77 Appendix H Wind Rose for Heathrow (knots) Wind speed (m/s)

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