PRELIMINARY ENVIRONMENTAL INFORMATION REPORT · 7.5 Embedded environmental measures 7.29 7.6...

Heathrow Expansion PRELIMINARY ENVIRONMENTAL INFORMATION REPORT: Chapter 7: Air quality and odour

© Heathrow Airport Limited 2019

Volume 1, Chapter 7

Air quality and odour



CONTENTS

7. Air quality and odour 7.1

7.1 Introduction 7.1

7.2 Relevant legislation, policy and other important and relevant matters 7.2 Introduction 7.2 Relevant legislation, policy and other important and relevant matters 7.2 Regional and local planning policy 7.8 Other important and relevant matters 7.9

7.3 Scoping and engagement 7.9 Overview 7.9 Scoping Opinion 7.9 Technical engagement 7.16

7.4 Scope of the assessment 7.18 Overview 7.18 Spatial scope and study area 7.18 Temporal scope 7.21 Receptors 7.23 Identification of potential effects 7.24 Effects no longer being considered 7.25

7.5 Embedded environmental measures 7.29

7.6 Methodology for baseline data gathering 7.40 Desk study 7.40

7.7 Assessment methodology for PEIR 7.41 Assessment methodology evolution 7.41 Construction assessment methodology 7.43 Operational assessment methodology 7.47 Cumulative effects 7.53

7.8 Assumptions and limitations of this PEIR 7.53

7.9 Overall baseline 7.56 Current baseline 7.56 Future baseline 7.65

7.10 Assessment of air quality and odour effects 7.66 Introduction 7.66 Construction 7.66 Pollutant concentrations during construction and operation 7.74 EU limit value compliance 7.121 Operational odour 7.127

7.11 Preliminary assessment of significance 7.130

7.12 Assessment of cumulative effects 7.134 Introduction 7.134 Emissions from road traffic 7.134 Emissions from other sources 7.136 Phase 1: c.2022-2026 7.138 Phase 2: c. late 2026-2035 7.138 Phase 3: c.2036-2050 7.139

7.13 Consideration of additional environmental measures and compensation 7.139

7.14 Next steps 7.139



Introduction 7.139 Baseline 7.139 Assessment 7.139 Engagement 7.140

TABLE OF TABLES

Table 7.1: Legislation relevant to air quality and odour 7.2 Table 7.2: National planning policies relevant to air quality and odour 7.6 Table 7.3: PINS Scoping Opinion 7.10 Table 7.4: Examples of where the air quality objectives should apply (Defra, 2016) 7.23 Table 7.5: Potential effects on air quality and odour receptors scoped in for further assessment7.24 Table 7.6: Effects no longer considered in this PEIR 7.26 Table 7.7: Summary of the embedded environmental measures in the design and how these influence the air quality and odour assessment 7.30 Table 7.8: Summary of the good practice environmental measures and how these influence the air quality and odour assessment 7.35 Table 7.9: Data sources used to inform the air quality and odour assessment 7.40 Table 7.10: Assessment methodology for the PEIR and EIA 7.41 Table 7.11: Sensitivity of area to dust soiling effects on people and properties 7.44 Table 7.12: Sensitivity of area to human health impacts 7.45 Table 7.13: Matrix to determine pathway effectiveness 7.46 Table 7.14: Risk of odour exposure at the specific receptor location 7.47 Table 7.15: Descriptors of odour impact magnitude 7.47 Table 7.16: Impact descriptors for individual receptors – urban road network 7.51 Table 7.17: Impact descriptors for individual receptors – Strategic Road Network 7.52 Table 7.18: UK air quality objectives and pollutants – LAQM in England 7.56 Table 7.19: Automatic air quality monitoring station details and measured annual mean NO2 concentrations (µg/m3) 7.60 Table 7.20: Automatic air quality monitoring station details and measured annual mean PM10 concentrations (µg/m3) 7.62 Table 7.21: Automatic air quality monitoring station details and measured annual mean PM2.5 concentrations (µg/m3) 7.63 Table 7.22: Dust emission magnitude 7.66 Table 7.23: Sensitivity of areas to dust soiling effects and human health effects 7.67 Table 7.24: Risks of dust soiling impacts and human health impacts 7.68 Table 7.25: Construction odour risk-based assessment 7.73 Table 7.26: Dispersion modelling results for Harmondsworth 7.77 Table 7.27: Dispersion modelling results for West Drayton 7.80 Table 7.28: Dispersion modelling results for Sipson 7.83 Table 7.29: Dispersion modelling results for Harlington 7.86 Table 7.30: Dispersion modelling results for Hayes 7.89 Table 7.31: Dispersion modelling results for Cranford Cross 7.91 Table 7.32: Dispersion modelling results for Cranford 7.93 Table 7.33: Dispersion modelling results for Heston 7.95 Table 7.34: Dispersion modelling results for Hounslow (Central and South) 7.97 Table 7.35: Dispersion modelling results for Hounslow (West and Heath) 7.99 Table 7.36: Dispersion modelling results for Feltham North 7.101 Table 7.37: Dispersion modelling results for Bedfont 7.103 Table 7.38: Dispersion modelling results for Stanwell 7.105 Table 7.39: Dispersion modelling results for Stanwell Moor 7.107 Table 7.40: Dispersion modelling results for Poyle 7.109 Table 7.41: Dispersion modelling results for Colnbrook 7.111 Table 7.42: Dispersion modelling results for Brands Hill 7.113 Table 7.43: Dispersion modelling results for Iver and Richings Park 7.116



Table 7.44: Address points within Core AQO Assessment Area by impact descriptor 7.118 Table 7.45: Address point count by magnitude of change in concentration 7.118 Table 7.46: Local air quality receptors informing significance 7.119 Table 7.47: Overall evaluation of local air quality (NO2) significance 7.119 Table 7.48: NO2 annual mean EU limit value compliance in 2022 7.123 Table 7.49: NO2 annual mean EU limit value compliance in 2027 7.123 Table 7.50: NO2 annual mean EU limit value compliance in 2030 7.124 Table 7.51: Operational odour risk-based assessment 7.129 Table 7.52: Summary of significance of adverse and beneficial effects 7.131 Table 7.53: Air quality, odour and dust CEA screening 7.136 Table 7.54: Developments brought forward for CEA 7.137

TABLE OF GRAPHICS

Graphic 7.1: Tiered assessment of potential effects outside of the Core AQO Assessment Area 7.50 Graphic 7.2: Wind rose for Heathrow Airport meteorological data 2013 – 2017 7.72

APPENDICES

Appendix 7.1: Technical appendix on dispersion modelling


7.1 © Heathrow Airport Limited 2019

7. AIR QUALITY AND ODOUR

7.1 Introduction

7.1.1 This chapter of the Preliminary Environmental Information Report (PEIR) presents

the preliminary results of the assessment of the likely significant effects of the

DCO Project with respect to air quality and odour. It should be read in conjunction

with the project description provided in Chapter 6: DCO Project description and

the relevant parts of the following Chapters:

1. Chapter 8: Biodiversity – for the likely effects on biodiversity

2. Chapter 12: Health – for the likely effects on health

3. Chapter 23: Bibliography

4. Glossary of terms and list of abbreviations.

7.1.2 This chapter describes:

1. The planning policy, legislation and other relevant documentation that has

informed the assessment (Section 7.2: Relevant legislation, policy and

other important and relevant matters)

2. The outcome of consultation and external engagement that has been

undertaken, including how matters relating to air quality and odour within the

Scoping Opinion received in July 2018 have been addressed (Section 7.3:

Scoping and engagement)

3. The scope of the assessment for air quality and odour (Section 7.4: Scope of

the assessment)

4. Embedded measures relevant to air quality and odour (Section 7.5:

Embedded environmental measures)

5. The methods used for the baseline data gathering (Section 7.6: Methodology

for baseline data gathering)

6. The assessment methods used for the PEIR (Section 7.7: Assessment

methodology for PEIR)

7. The assumptions and limitations of the PEIR assessment (Section 7.8:

Assumptions and limitations of this PEIR)

8. The overall baseline (Section 7.9: Overall baseline)

9. The assessment of air quality and odour effects (Section 7.10: Assessment

of air quality and odour effects)



10. A summary of significance of positive and negative air quality and odour effects

identified in the PEIR (Section 7.11 Preliminary assessment of

significance)

11. The assessment of cumulative effects (Section 7.12 Assessment of

cumulative effects).

12. Consideration of any additional mitigation required (Section 7.13:

Consideration of additional environmental measures and compensation)

13. An outline of further work to be undertaken for the Environmental Statement

(ES) (Section 7.14: Next steps).

7.1.3 In-combination effects are dealt with in Chapter 22: In-combination effects.

7.2 Relevant legislation, policy and other important and relevant matters

Introduction

7.2.1 This section identifies the legislation, policy and other documentation that has

informed the preliminary assessment of effects with respect to air quality and

odour. Further information on policies relevant to the EIA and their status is

provided in Chapter 2: Legislative and policy overview of this PEIR.

Relevant legislation, policy and other important and relevant matters

7.2.2 Table 7.1 lists the legislation relevant to the assessment of the effects on air

quality and odour receptors.

Table 7.1: Legislation relevant to air quality and odour

Legislation description Relevance to assessment

Directive 2008/50/EC on Ambient Air Quality and Cleaner Air for Europe

This Directive lays down measures aimed at the

following (Article 1):

‘1. defining and establishing objectives for ambient

air quality designed to avoid, prevent or reduce

harmful effects on human health and the

environment as a whole;

2. assessing the ambient air quality in Member

States on the basis of common methods and

criteria;

3. obtaining information on ambient air quality in

Regulated pollutants include sulphur dioxide (SO2),

nitrogen dioxide (NO2), nitrogen oxides (NOx),

particulate matter (PM10 and PM2.5), lead (Pb),

benzene (C6H6) and carbon monoxide (CO).

NO2 and PM are considered to be the main pollutants

of concern in the UK given their concentrations

relative to EU limit values. NOX (the sum of nitric

oxide (NO) and NO2) is emitted as a result of

combustion processes (e.g. from vehicles, aircraft




order to help combat air pollution and nuisance

and to monitor long-term trends and improvements

resulting from national and Community measures;

4. ensuring that such information on ambient air

quality is made available to the public;

5. maintaining air quality where it is good and

improving it in other cases;

6. promoting increased cooperation between the

Member States in reducing air pollution.’

It is stated that (Recital 9):

‘Air quality status should be maintained where it is

already good, or improved. Where the objectives

for ambient air quality laid down in this Directive

are not met, Member States should take action in

order to comply with the limit values [EU limit

values] and critical levels, and where possible, to

attain the target values and long-term objectives.’

and heating plant). Emissions are expressed in terms

of mass of NOx, whereas human health effects relate

to NO2 concentrations. Although some NO2 is emitted

directly during combustion, additional NO2 is formed

following release, principally via the interaction of NO

with ozone (O3). Thus, emissions of both NO and NO2

are important.

PM is also emitted from combustion processes. For

PM there are additional non-exhaust contributions,

including brake wear, tyre erosion, road abrasion and

resuspension.

The Directive is transposed into UK legislation

through the Air Quality Standards Regulations 2010.

The UK Government has prepared the Air quality plan

for nitrogen dioxide (NO2) in UK (2017) detailing a

range of measures designed to meet requirements of

the Directive.

In the UK, only monitoring and modelling carried out

by UK Central Government meets the specification

required to assess compliance with the EU limit

values. Defra assesses compliance using the

Pollution Climate Mapping (PCM) model and the

Automatic Urban and Rural Network (AURN) of

monitoring sites. Concentrations are predicted using

the PCM model at locations 4m from the kerbsides of

9,000 representative road links. The base year PCM

modelled results are calibrated against measured

concentrations from the AURN and then verified.

Defra’s PCM modelling data have been used for

assessment of compliance with EU limit values. The

assessment methodology is set out in Section 7.7.

Directive 2016/2284/EU on the reduction of national emissions of certain atmospheric pollutants

The recitals describes the purpose of this Directive

as follows:

‘13. Member States should comply with the

emission reduction commitments set out in this

Directive from 2020 to 2029 and from 2030

onwards.’ and

‘18. Each Member State should draw up, adopt

and implement a national air pollution control

programme with a view to complying with its


through the National Emission Ceilings Regulations

2018. Specified pollutants include SO2, NOX, CO,

PM10, PM2.5 and Pb which also have Air Quality

Objectives (AQOs). The Directive deals with total

emissions from the UK, and not those of specific

projects or sectors.

Potential emissions associated with the DCO Project

will be reduced through the embedded measures




emission reduction commitments, and to

contributing effectively to the achievement

of the air quality objectives.’

detailed in Section 7.5. These measures will support

the Government in meeting the National Emission

Ceiling Regulations.

Directive (EU) 2015/2193 on the limitation of emissions of certain pollutants into the air from MCPs

(Medium Combustion Plants)

The recitals describe the purpose of this Directive

as follows:

‘15. In order to ensure the control of emissions of

sulphur dioxide, nitrogen oxides and dust into the

air, each medium combustion plant should operate

only if it has been granted a permit or been

registered by the competent authority, based on

information submitted by the operator.

16. For the purposes of controlling emissions into

the air from medium combustion plants, emission

limit values and

requirements for monitoring should be set out in

this Directive.’


through The Environmental Permitting (England and

Wales) (Amendment) Regulations 2018. Permitting

requirements were introduced for MCPs and specified

generators.

Part IV of the Environment Act 1995

This requires that:

Section 82(1) ‘Every local authority shall from time

to time cause a review to be conducted of the

quality for the time being, and the likely future

quality within the relevant period, of air within the

authority’s area.’ And that:

Section 83(1) ‘Where, as a result of an air quality

review, it appears that any air quality standards or

objectives are not being achieved, or are not likely

within the relevant period to be achieved, within

the area of a local authority, the local authority

shall by order designate as an air quality

management area [AQMA] (in this Part referred to

as a “designated area”) any part of its area in

which it appears that those standards or objectives

are not being achieved, or are not likely to be

achieved within the relevant period.’

This process of Local Air Quality Management

(LAQM), as detailed in the Environment Act, is an

integral part of delivering the Government's air quality

objectives (AQOs) which are set out in the Air Quality

(England) Regulations 2000, prepared pursuant to

section 87(2)(b) of the Environment Act 1995 (which

allows the Government to make regulations setting

AQOs).

The declaration of an AQMA requires the local

planning authority (LPA) to implement an Air Quality

Action Plan. From the 2016 reporting year, Defra

introduced a streamlined process with a single

Annual Status Report for reporting on LAQM.

The assessment methodology set out in Section 7.7

uses data collected by LPAs as part of the LAQM

regime and embedded measures presented in

Section 7.5 are consistent with the aims of local Air

Quality Action Plans.

The Air Quality (England) Regulations 2000

The Air Quality (England) Regulations 2000 came

into force on 6 April 2000 and set Air Quality

Objectives (AQOs).

AQOs are set for the restriction of the levels at which

particular substances are present in the air.




Air quality is assessed in relation to the AQOs. These

are further defined in paragraph 17 of The Air Quality

Strategy for England, Scotland, Wales and Northern

Ireland (Defra, 2007) as “policy targets often

expressed as a maximum ambient concentration not

to be exceeded, either without exception or with a

permitted number of exceedances, within a specified

timescale’.

The assessment methodology is set out in Section

7.7.

The Air Quality Standards Regulations 2010

The Air Quality Standards Regulations 2010 came

into force on 11 June 2010 and transpose

Directive 2008/50/EC into UK legislation. The limit

values in Directive 2008/50/EC are transposed into

the Regulations as Air Quality Standards for

concentrations recorded over a given time period,

with attainment dates in line with the Directive.

Defra’s PCM modelling data have been used for

assessment of compliance with EU limit values. The

assessment methodology is set out in Section 7.7.

The Environmental Protection Act 1990

Under Part III Section 79 (1) the following matters

constitute ‘statutory nuisances’:

(b) smoke emitted from premises so as to be

prejudicial to health or a nuisance;

(c)fumes or gases emitted from premises so as to

be prejudicial to health or a nuisance;

(d) any dust, steam, smell or other effluvia arising

on industrial, trade or business premises and

being prejudicial to health or a nuisance’

Dust emissions from construction activities and odour

emissions from construction and operation activities

are considered in this assessment. The potential and

likelihood of emissions causing nuisance is the key

consideration of the assessment.

National Emission Ceilings Regulations 2018

It is stated in Part 2, regulation 3.(1) that:

‘The Secretary of State must—

(a) by 15th February each year prepare an

inventory of emissions occurring within the United

Kingdom of the pollutants specified in Table 1 of

Schedule 1, for the calendar year before the

previous calendar year;

(b) by 15th March 2019 and every two years after

that date prepare and update a projection of

emissions occurring within the United Kingdom of

the pollutants set out in Table 2 of Schedule 1, for

the years specified in column 3 of that table that

The National Emission Ceilings Regulations 2018

came into force on 1 July 2018 and transpose

Directive 2016/2284/EU on the reduction of national

emissions of certain atmospheric pollutants into UK

legislation. Specified pollutants include SO2, NOX,

CO, PM10, PM2.5 and Pb which also have AQOs.



detailed in Section 7.5. These measures will support

the government in meeting the National Emission




have not yet passed.’

It is stated in Part 4, 9.(1) that:

‘The Secretary of State must prepare and

implement a national air pollution control

programme in order to limit anthropogenic

emissions in accordance with the national

emission reduction commitments.’

Ceiling Regulations.

Total emissions of SO2 (from the Landing and Take-

Off (LTO) cycle), NOX, PM10 and PM2.5 from sources

within the Core AQO Assessment Area will be

reported in the ES for each assessment year when

model inputs are finalised for comparison with the

totals in the NAEI, and the amounts specified in the

National Emission Ceiling Regulations.

The Environmental Permitting (England and Wales) (Amendment) Regulations 2018

These Regulations amend the Environmental

Permitting (England and Wales) Regulations 2016.

Part 2 of these Regulations require operators to

obtain a permit and monitor and manage

emissions to comply with emission limit values.

The 2018 Amendment Regulations incorporate the

EU MCP Directive into legislation and introduce

permitting requirements for MCPs and specified

generators.

Specific emission sources requiring an Environmental

Permit will be detailed in the ES.

7.2.3 Table 7.2 lists the national planning policy relevant to the assessment of the

effects on air quality and odour receptors.

Table 7.2: National planning policies relevant to air quality and odour

Policy description Relevance to assessment

Airports National Policy Statement (ANPS)

The ANPS (Department for Transport, 2018) is the

primary basis for decision making on the

application for development consent for the DCO

Project.

Chapter 2: Legislative and policy overview

provides an explanation of the relevance of the

ANPS to the Project in general terms.

The requirements for the air quality assessment

are detailed in paragraphs 5.32 to 5.34. In

paragraph 5.32 it is stated that:

‘The applicant should undertake an assessment of

the project, to be included as part of the

environmental statement, demonstrating to the

Secretary of State that the construction and

operation of the Northwest Runway will not affect

the UK’s ability to comply with legal obligations.

Failure to demonstrate this will result in refusal of

development consent.’



detailed in Section 7.5.

The assessment reports current baseline air quality

conditions in Section 7.9 and forecasts the future

baseline in each key assessment year during the

construction and operation of the DCO Project,

including when at full capacity.

The assessment set out in Section 7.10 has been

carried out to meet the requirements of the ANPS.

Section 7.10 details predicted air quality during

construction, at the time of opening and in other

assessment years, both assuming that the DCO

Project is not built, and taking account of the impact

of the DCO Project. The latest Defra projections of

air quality are used in this assessment. Pollutant

concentrations are considered in relation to AQOs

and EU limit values to consider effects on AQMAs

and in relation to EU limit value compliance. In

particular, Section 7.10 sets out how the DCO




The requirements for measures to reduce air

quality impacts are detailed in paragraphs 5.35 to

5.41. The decision making process is discussed in

paragraphs 5.42 and 5.43. In paragraph 5.42 it is

stated that:

‘The Secretary of State will consider air quality

impacts over the wider area likely to be affected, as

well as in the vicinity of the scheme. In order to

grant development consent, the Secretary of State

will need to be satisfied that, with mitigation, the

scheme would be compliant with legal obligations

that provide for the protection of human health and

the environment.’

Project, including embedded environmental

measures detailed in Section 7.5, will not affect the

UK’s ability to comply with legal obligations, including

EU limit values and AQOs. The conclusions of

significance evaluation are detailed in Section 7.13.

Total pollutant emissions and how these compare to

the National Atmospheric Emissions Inventory

(NAEI) and the levels stipulated in the National

Emissions Ceilings Regulations will be reported in

the ES when plans and model inputs are finalised.

National Policy Statement for National Networks (NN NPS)


provides an explanation of the relevance of the NN

NPS to the DCO Project in general terms.

This document details similar requirements for the

air quality assessment to the ANPS in paragraphs

5.6 to 5.9. In paragraph 5.13, it is stated that:

‘The Secretary of State should refuse consent

where, after taking into account mitigation, the air

quality impacts of the scheme will:

- result in a zone/agglomeration which is currently

reported as being compliant with the Air Quality

Directive becoming non-compliant; or

- affect the ability of a non-compliant area to

achieve compliance within the most recent

timescales reported to the European Commission

at the time of the decision.’

The requirements for measures to reduce air

quality impacts are detailed in paragraphs 5.14 and

5.15.



detailed in Section 7.5.

The assessment reports current baseline air quality

conditions in Section 7.9 and forecasts the future

baseline in each key assessment year during the

construction and operation of the DCO Project,

including when at full capacity.





of the DCO Project. Detailed dispersion modelling

has been undertaken. Pollutant concentrations are

considered in relation to AQOs and EU limit values to

consider effects on AQMAs and relation to EU limit

value compliance. In particular, Section 7.10 sets

out how the DCO Project, including embedded

environmental measures detailed in Section 7.5, will

not affect the UK’s ability to comply with legal

obligations, including EU limit values and AQOs. The

conclusions of significance evaluation are detailed in

Section 7.13.

National Planning Policy Framework (NPPF) 2019


provides an explanation of the relevance of the

NPPF (MHCLG, 2019) to the DCO Project in

general terms.

Paragraph 181 details how:

‘Planning policies and decisions should sustain and

contribute towards compliance with relevant limit

The embedded measures considered in the

assessment and presented in Section 7.5 are

consistent with, and support the aims of, the local Air

Quality Action Plans prepared following the

declaration of AQMAs.






values or national objectives for pollutants, taking

into account the presence of Air Quality

Management Areas and Clean Air Zones, and the

cumulative impacts from individual sites in local

areas. Opportunities to improve air quality or

mitigate impacts should be identified, such as

through traffic and travel management, and green

infrastructure provision and enhancement.’

Of relevance to odour, it is stated in paragraph 180

that:

‘Planning policies and decisions should also ensure

that new development is appropriate for its location

taking into account the likely effects (including

cumulative effects) of pollution on health, living

conditions and the natural environment’.



of the DCO Project. Detailed dispersion modelling

has been undertaken. Pollutant concentrations are

considered in relation to AQOs and EU limit values to

consider effects on AQMAs and relation to EU limit

value compliance. Section 7.10 also considers

potential odour impacts associated with the DCO

Project.

Regional and local planning policy

7.2.4 Appendix 2.1: Regional and local planning policy and other important and

relevant matters, Volume 3 presents the full list of the regional and local planning

policies relevant to the assessment of the effects on air quality and odour

receptors.

7.2.5 The local planning policies of the Greater London Authority (GLA) and the

following LPAs have been considered given their proximity to the Airport the

potential for changes in traffic flows on roads within their administrative areas:

1. London Borough of Hillingdon

2. London Borough of Hounslow

3. Spelthorne Borough Council

4. Slough Borough Council

5. Runnymede District Council

6. South Bucks District Council

7. London Borough of Richmond Upon Thames

8. Royal Borough of Windsor and Maidenhead

9. London Borough of Ealing

10. London Borough of Hammersmith and Fulham

11. Royal Borough of Kensington and Chelsea



12. London Borough of Wandsworth

13. Westminster City Council

14. Elmbridge Borough Council.

Other important and relevant matters

7.2.6 A summary of other documentation relevant to the assessment undertaken in air

quality and odour is provided within Appendix 2.1. Air quality Action Plans

produced by the LPAs referenced in paragraph 7.2.5 are included given the

potential for changes in traffic flows on roads within their administrative areas.

7.3 Scoping and engagement

Overview

7.3.1 This section describes the matters raised in relation to air quality and odour in the

Scoping Opinion and how the assessment has responded to those matters. It also

provides details of the ongoing technical engagement that has been undertaken

with stakeholders and individuals. An overview of engagement undertaken can be

found in Section 1.5 of Chapter 1: Introduction.

7.3.2 Engagement has taken the form of discussions and meetings and is summarised

in the following sections.

Scoping Opinion

7.3.3 A Scoping Report requesting a Scoping Opinion was submitted to the Secretary of

State, administered by the Planning Inspectorate (PINS) on behalf of the Secretary

of State on 21 May 2018. The Scoping Report set out the proposed air quality and

odour assessment methodologies and outlined the baseline data collected to date

and proposed for the ES.

7.3.4 A Scoping Opinion was adopted by PINS on behalf of the Secretary of State on 2

July 2018. Table 7.3 sets out the comments received in Section 4 of the PINS

Scoping Opinion (‘Aspect based scoping tables’) for air quality and odour and how

they have been addressed in this PEIR. A full list of the PINS Scoping Opinion

comments and responses is provided in Appendix 5.1: Response to the

Scoping Opinion. The information provided in the PEIR is preliminary and

therefore not all the Scoping Opinion comments have been able to be addressed

at this stage, however all comments will be addressed within the ES.



Table 7.3: PINS Scoping Opinion

PINS ID

number Scoping Opinion comment How is this addressed?

1 Table 3.6 of the Scoping Report excludes

operational air quality effects on rivers and

flood storage. The Inspectorate considers

that the potential for air quality effects on

rivers and flood storage areas due to

deposition of pollutants should be taken into

account within the assessment, particularly

where the Proposed Development has

potential to give rise to stagnant or low flow

conditions.

Deposition rates will be calculated and used in the

ES for the assessment of effects on rivers and

flood storage by considering the total deposition in

relation to the volume of water.

2 The Applicant proposes to scope out the

identified pollutants on the basis that

previous low concentrations (2010 and

earlier) mean that Local Authority

monitoring has ceased and based on

previous best practice guidance set out in

the DCO Project for the Sustainable

Development of Heathrow (PSDH)

(Department for Transport, 2006). However,

SO2, NO2 and NOX are identified as relevant

combustion products for aviation projects by

the CAA and the lack of recent baseline

data to supplement the assessment

undermines confidence that this position

remains the same.

The definition of activities involving

combustion includes “aircraft movements on

the new runway and taxiways, land-based

activities in support of airport operation and

road traffic”

In the absence of a detailed description of

what the potential sources arising from land-

based activities are (eg such as new

generation plant and rail terminal sources),

the Inspectorate considers that assessment

of these pollutants cannot be scoped out at

present. In addition, Biodiversity operational

scope item 1 in Table 4.6 suggests that

deposition of nitrogen and sulphur will be

assessed for impacts on habitats and water,

which would appear to contradict the need

to scope out consideration of SO2 from

combustion processes.

The Applicant should demonstrate that it is

unlikely to give rise to significant air quality

It was stated in the Scoping Report that

concentrations of pollutants other than NO2, PM10

and PM2.5 that could affect human health at

sensitive receptors would be scoped out of the

assessment. The list of pollutants, determined

with reference to the AQOs, the Air Quality

Standards Regulations 2010 and The National

Emission Ceilings Regulations 2018 was: CO,

SO2, lead, benzene and 1,3 butadiene, arsenic,

cadmium, nickel, mercury, benzo(a)pyrene,

benzo(b)fluoranthene, benzo(k)fluoranthene,

indeno(1,2,3-cd)pyrene, dioxins/furans, PCBs and

HCB.

It is understood that this Scoping Opinion

comment relates to the lack of consideration of

NOX and SO2, with reference to CAA guidance.

To confirm, NOX emissions have been modelled

from all relevant combustion sources in the

assessment detailed in Section 7.10. Modelled

NOX concentrations have been used to calculate

NO2 concentrations.

Following receipt of the Scoping Opinion, the

decision has been made to additionally model

sulphur emissions from aircraft to predict SO2

concentrations in line with CAA guidance. SO2

concentrations resulting from road traffic have not

been modelled as road traffic is no longer a

significant source in the UK; more stringent

legislation on the sulphur content of liquid fuels

has helped to reduce emissions, and emissions

from gas oil and road diesel have decreased by

91% since 1990 (Defra, 2018a). No other sources

with high sulphur fuels that could give rise to



PINS ID


effects from these pollutants through the

provision of a detailed screening

assessment where relevant.

significant sulphur emissions have been identified.

Nitrogen deposition rates will be calculated and

used in the ES for the assessment of effects on

biodiversity.

3 The Scoping Report states that local

emissions associated with expansion are

unlikely to significantly alter background O3

concentrations. The PDSH study identified

that ozone was not a priority area for

modelling the impact of Heathrow

emissions.

The definition of activities involving

combustion includes “aircraft movements on

the new runway and taxiways, land based

activities in support of airport operation and

road traffic”. In the absence of a detailed

description of the land based activities, the

potential for sources of ozone arising from

sources such as new generation plant

cannot be excluded.

The Applicant should demonstrate that it is

unlikely to give rise to significant air quality

effects from this pollutant through the

provision of a detailed screening

assessment where relevant.

Further detail is provided on the decision to scope

out the assessment of O3 concentrations in

Section 7.4.

4 The Inspectorate considers that insufficient

justification has been provided to scope out

an assessment of secondary particulate

matter, in particular the lack of description of

the specific pollutants that have the

potential to form secondary particulates.

Further detail is provided on the decision to scope

out the assessment of secondary particulates in

Section 7.4.

5 The Inspectorate considers that significant

effects are not anticipated in relation to this

matter [jettisoning of fuel from aircraft in

Flight] and that it may be scoped out from

further assessment. This is on the basis that

jettisoning of fuel is an infrequent and

abnormal event required for the purposes of

operational safety with existing operational

procedures in place that are designed to

avoid odour effects.

Noted.

6 The list of items to be assessed in Table 4.6

includes vehicles on public highways

however it is unclear whether emissions

from vehicles within the operational site are

proposed to be assessed.

For example, Table 3.6 excludes air quality

The dispersion modelling used to predict pollutant

concentrations for assessing potential air quality

effects on human health includes emissions from

vehicles within car parks and emissions from

vehicles within the operational site. Further details

are provided in Appendix 7.1: Technical



PINS ID


effects from car parking areas. For the

avoidance of doubt the ES should include

an assessment of on-airport vehicle

emissions and their effect on human and

ecological receptors.

appendix on dispersion modelling.

7 Emissions from aircraft operation are

scoped in with respect to effects on human

health but not for biodiversity. The

Inspectorate considers that the ES should

consider the potential for likely significant

effects on biodiversity from aircraft

emissions.

Nitrogen deposition rates will be calculated and

used in the ES for the assessment of effects on

biodiversity.

8 The scope of the odour assessment focuses

on construction site emissions and Volatile

Organic Compounds (VOC) from aircraft.

The effect of odour on sensitive receptors

arising from odour sources such as

relocated wastewater treatment plant

infrastructure and new waste and recycling

centres should also be assessed in

accordance with IAQM guidelines unless

otherwise justified.

The risk-based assessment (refer to Section

7.10) relates to all potential sources of odour

emissions (e.g. aviation fuel, waste facilities,

wastewater treatment plant). The potential for

odorous emissions to impact on amenity has been

considered in accordance with IAQM guidance

(refer to Section 7.10).

9 IAN174/13 excludes assessment of PM2.5

as it predates 1 January 2015, which is set

out in The Air Quality Standards

Regulations 2010 as the date by which the

PM2.5 limit value must be met.

Whilst the general principles of the IAN may

be followed, The Applicant should include

assessment of the effects of PM2.5.



effects on human health includes emissions of

PM2.5 from all relevant sources. Predicted PM2.5

concentrations are reported in Section 7.10.

10 The Applicant proposes to predict pollutant

concentrations across a 12km x 11km ‘core

assessment area’ based on findings from

previous studies. The Inspectorate

considers that The Applicant should not

apply an arbitrary limit to the assessment

area based on previous studies, since the

Proposed Development is more extensive

and covers a wider geographic area than

set out in those studies. The Inspectorate

considers that the model extent should be

defined by the area over which significant

air quality effects arising from the Proposed

Development may occur. This should be

clearly defined within the ES.

The ES should have regard to the Air

Navigation Guidance 2017 with respect to

The assessment extent is defined by the area

over which significant effects arising from the

Project could occur.

As such the assessment is not limited to the Core

AQO Assessment Area. The assessment detailed

in Section 7.10 has considered changes in road

traffic flows through the tiered assessment and

evaluated locations where additional assessment

in the form of detailed dispersion modelling may

be required.



PINS ID


the parameters for assessment of aviation

emissions on local air quality.

11 The Inspectorate considers that DMRB

screening criteria are appropriate for the

identification of affected road links on the

strategic road network.

The ES should apply the screening criteria

set out in the EPUK and Institute of Air

Quality Management (IAQM) 2017 guidance

‘Land Use Planning & Development Control:

Planning for Air Quality’ (the EPUK/IAQM

guidance) to identify affected road links on

the urban road network.

The DMRB screening criteria (Strategic Road

Network) and EPUK/IAQM criteria for Air Quality

Assessment (urban road network) have been

used in a tiered assessment process described in

Section 7.7 to identify potentially affected road

links in particular assessment years.

12 These paragraphs [5.4.13 – 5.4.14] suggest

that the assessment methodology will focus

on the incremental change in road traffic

related NO2 concentrations as a result of

the Project. The ES should consider and

model concentrations of other relevant

vehicle emissions such as PM10 and PM2.5.

In addition, as currently written, the text

appears to exclude consideration of airport

emissions from the compliance assessment.

For the avoidance of doubt the Inspectorate

considers that these should be included

within the assessment.



effects on human health includes emissions of

PM10 and PM2.5.

The effect of airport emissions on concentrations

relevant to compliance with EU limit values is

included in the assessment.

13 The Inspectorate notes that it is not

proposed to include supplementary baseline

monitoring for PM or NO2 since these are

routinely monitored in the area by The

Applicant and the Local Authorities. In light

of the extended nature of the development

(eg including areas proposed for flood

storage and borrow pits) that fall outside the

immediate Heathrow area, the ES should

include baseline monitoring for the wider

study area where relevant. The Applicant

should make effort to agree the final scope

of such monitoring with relevant

consultation bodies once the footprint of the

Proposed Development has been

confirmed.

The ES should document the proposed

method of data collection, which should be

conducted in accordance with recognised

standards.

The baseline data within the ES should be

up to date and represent the entire study

A DCO Project specific air quality monitoring

programme will be established. The scope of such

monitoring will be agreed with relevant

consultation bodies.

The proposed monitoring programmes will be

documented in the ES.

The baseline presented in Section 7.9 includes

data from stations operated by relevant LPAs,

including data available on the London Air Quality



PINS ID


area, details such as the location of

monitoring stations and the extent of

AQMAs should be confirmed with the

consultation bodies.

The air quality monitoring should draw on

the data held within the London Air Quality

Network and from adjacent local planning

authorities, identifying any areas of localised

poor air quality (eg M25, M4). Efforts should

be made to agree the scope and extent of

air quality baseline datasets and model

validation requirements with the relevant

local planning authorities where possible,

drawing on existing local authority

monitoring supplemented by additional

monitoring where necessary. Baseline

datasets should comprise a minimum 6

months of data. The odour and dust

baseline dataset should be supported by

any complaints history information.

The Scoping Report proposes that PM, dust

deposition and odour surveys will be

undertaken in advance of the construction

programme. The Applicant should ensure

that the draft CEMP includes sufficient

provision for pre-construction monitoring

consistent with the relevant Institute of Air

Quality Management (IAQM) guidance. The

ES should describe the methodological

approach to be adopted for each of the

proposed studies.

Network. The baseline also includes information

on odour complaints received. Where additional

dispersion modelling has been undertaken outside

of the Core AQO Assessment Area,

supplementary baseline monitoring has been used

to verify the dispersion modelling.

The draft Code of Construction Practice

(CoCP) details construction monitoring

requirements and will include details on the

baseline monitoring required before the start of

the construction process.

14 It is proposed that deposition of sulphur is

scoped out from consideration of

eutrophication, since sulphur levels are very

low in the area and adjacent to the road

network. This approach excludes the

potential for deposition of sulphur from other

sources eg rail. The ES should screen the

potential effect of sulphur deposition from all

relevant sources including rail and consider

their potential for in-combination effects.

Rail emissions sources will be considered in the

ES using the guidance contained in Defra LAQM

Technical Guidance (LAQM.TG(16)).

15 The operational assessment should include

consideration of non-combustion PM

sources eg brake and tyre linings as well as

direct emissions from vehicle exhausts.

Through the application of the Defra Emissions

Factors Toolkit (EFT), non-combustion PM

emission sources such as brake and tyre wear

and road abrasion are included in the dispersion

modelling assessment. Reported PM

concentrations therefore include contributions

from these sources.



PINS ID


16 The operational assessment should

consider the potential for PM emissions

from non-combustion sources, such as the

wear of brake linings and tyres.

Through the application of Defra’s EFT, non-

combustion PM emission sources such as brake

and tyre wear and road abrasion are included in

the dispersion modelling assessment. Reported

PM concentrations therefore include contributions

from these sources.

17 The Scoping Report states that dispersion

modelling would not enable an evaluation of

significant effects associated with increased

Volatile Organic Compound (VOC) odour

therefore, in accordance with IAQM

guidance, a semi-quantitative approach to

the assessment will be undertaken. The ES

should fully justify the approach, including

detailed justification for not undertaking

dispersion modelling.

Potential sources of odour are discussed and the

assessment approach is justified in Section 7.7.

18 The Inspectorate considers that DMRB

significance criteria are appropriate for the

identification of affected road links on the

strategic road network. Criteria for exposure

to PM2.5 should be set out since these are

not specifically addressed within DMRB.

The ES should apply the significance

criteria set out in the EPUK/IAQM guidance

or similar to identify affected road links on

the urban road network.

Where the Proposed Development will give

rise to non-vehicular emissions (such as

those arising from on-site energy

generation), the relevant sector specific

guidance produced by the Environment

Agency should inform the assessment

criteria where necessary.

EPUK/IAQM impact magnitude descriptors have

been used to consider impacts at all receptors.

These criteria have also been used with regards

to PM2.5.

Overall local air quality effects have also been

considered using the approach in Interim Advice

Note (IAN) 174/13 (Highways Agency, 2013a).

Risks in relation to compliance with EU limit

values have been considered using the approach

in IAN 175/13 (Highways Agency, 2013b).

Specific emissions sources requiring an

Environmental Permit will be detailed in the ES.

The relevant sector specific guidance produced by

the Environment Agency will inform the

assessment criteria where necessary.

19 The ES should demonstrate how the

measures set out within the draft CoCP will

be secured e.g. by providing cross

references to the relevant draft DCO

requirement.

This will be set out in the ES.

20 Whilst the Inspectorate acknowledges that

use of rail freight has potential to reduce

vehicle related air quality impacts, the scope

of assessment should screen the potential

for increased rail freight emissions to give

rise to air quality impacts during

construction and operation, including

emissions of SO2.

Rail emissions sources will be considered in the

ES using the guidance contained in Defra LAQM

Technical Guidance (LAQM.TG(16)).

21 The air quality assessment currently Defra background pollution datasets have been



PINS ID


proposes to use the NAEI dataset, the ES

should be based on the most relevant

information available, for example the

London Atmospheric Emissions Inventory

as highlighted by TfL. Robust justification

should be provided if alternative datasets

are relied on for the purposes of the

assessment.

used. Emissions from local sources such as the

Lakeside Waste Management Facility have been

explicitly modelled from available data.

22 The ES should document any assumptions

used in the derivation of NO2

concentrations.

The ES will set out the assumptions used in the

derivation of NO2 concentrations. Assumptions

related to the preliminary assessment set out in

this PEIR are detailed in Appendix 7.1.

Technical engagement

Introduction

7.3.5 Technical engagement has been ongoing with a number of prescribed and non-

prescribed consultation bodies in relation to air quality and odour. A summary of

engagement undertaken up to finalisation of this PEIR is outlined in this section.

Heathrow Strategic Planning Group (HSPG)

7.3.6 Engagement with the HSPG has been ongoing since November 2017. At the first

meeting on 9 November 2017 the purpose of the group was established and an

overview of the DCO Project was provided along with a high-level summary of

Heathrow’s approach to air quality assessment. The second meeting was held on

8 February 2018, to discuss EIA scoping and the published Airport Expansion

Consultation One materials.

7.3.7 There were additional meetings held on the 7 June 2018, when the EIA Scoping

Report was discussed, and 17 October 2018, when further details were provided

on the approach to assessment following receipt of the PINS EIA Scoping Opinion.

Topics covered included the study area, screening and significance criteria to be

applied, baseline monitoring, conversion of NOX to NO2 concentrations and

dispersion model verification.

7.3.8 One key issue raised was that the assessment should make use of air quality

monitoring data collected by LPAs. Automatic monitoring data collected LPAs has

been used in the dispersion modelling verification process. Verified modelled

annual mean NO2 concentrations have been compared to measurements in the

study area undertaken by the LPAs using NO2 diffusion tubes. This is detailed in

Appendix 7.1: Technical appendix on dispersion modelling, Volume 3.



7.3.9 South Bucks District Council and Buckinghamshire County Council raised the

issue of impacts on designated ecological sites (e.g. Burnham Beeches Special

Area of Conservation) and that impacts should be assessed where traffic data

indicate that there may be the potential for significant adverse effects. As such, an

assessment will be carried out as part of the EIA, and detailed in the ES, where

predicted traffic data and screening criteria indicate that trip generation could

potentially result in significant effects. The effect of the meteorological data used in

terms of worst-case impacts on receptors in different areas was also discussed.

Dispersion modelling has been carried out with data from 2015, 2016 and 2017.

2017 meteorological data was shown to lead to the highest overall concentrations

in the study area. Results are therefore reported for 2017 to illustrate the likely

effects of the DCO Project.

Highways England

7.3.10 An initial meeting was held on 7 September 2017. This was followed by a meeting

to discuss the scope of the assessment which took place on 8 March 2018.

7.3.11 Reference was made to current government guidance that is available. The

Highways Agency (now Highways England) Design Manual for Roads and Bridges

(DMRB) (Highways Agency, 2007) contains guidance that can be used for

screening of roads that are likely to be affected by proposals. Interim Advice Note

174/13 (Highways Agency, 2013a) provides guidance on the evaluation of

significance for Highways Agency schemes. Interim Advice Note 175/13

(Highways Agency, 2013b) provides guidance on the assessment of compliance

with the EU limit value.

7.3.12 The two IANs have been used in determination of the nature of effects at receptors

on the Strategic Road Network, and in relation to compliance with EU limit values.

Transport for London (TfL)

7.3.13 An initial meeting was held on 17 September 2018. An overview of the DCO

Project was provided along with a high-level summary of the approach to the air

quality assessment.

7.3.14 Further details on the approach to assessment were provided at a meeting held on

30 October 2018. Topics covered included the study area, screening and

significance criteria to be applied, baseline monitoring, conversion of NOX to NO2

concentrations and dispersion model verification.

7.3.15 Dispersion modelling was discussed in more detail in the meeting of 12 February

2019. Topics covered included the approach to background pollutant

concentrations, model verification and sensitivity tests.



Environment Agency

7.3.16 A meeting was held with the Environment Agency on 23 April 2018. The proposed

scope of assessment was presented. It was confirmed that the role of the

Environment Agency as a statutory consultee will not cover air quality, however it

will need to be consulted should any particular aspect of the DCO Project require

an Environmental Permit. Specific emissions sources requiring an Environmental

Permit will be detailed in the ES.

Natural England

7.3.17 Engagement with Natural England has included discussion in relation to potential

changes in concentrations and deposition rates of NOX, potentially resulting in

habitat degradation. Engagement and consideration of this effect is discussed in

more detail in in Chapter 8 of this PEIR.

7.4 Scope of the assessment

Overview

7.4.1 This section describes the spatial and temporal scope for the assessment as it

applies to air quality and odour and outlines the receptors on which assessment

has been undertaken.

7.4.2 This scope has been developed as the DCO Project has evolved and responds to

feedback received to date as detailed in Section 7.3. The information presented in

the PEIR is by its nature preliminary and should not be considered a ‘draft’ ES (in

accordance with PINS Advice Note 7). Further scope refinement may be required

to take full account of the preferred DCO Project design and subsequent

engagement.

Spatial scope and study area

Construction dust

7.4.3 The study area for construction dust effects has been informed by Greater London

Authority (GLA) (2014) and IAQM Guidance on the assessment of dust from

demolition and construction (IAQM, 2014). These guidance documents are

considered to represent best practice. Assessment has been carried out for all

individual work sites where there is a human receptor within:

1. 350m of the boundary of the relevant site

2. 50m of a route(s) used by construction vehicles on the public highway or haul

routes, up to 500m from the site entrance(s).



Odour

7.4.4 It is recognised that different sources of odour will affect receptors over different

distances due to the varying strength and nature of emissions. Assessment has

been carried out for odour sources associated with the DCO Project that could

potentially have an impact on receptors (during the construction and operation

phases). The assessment has considered the odour potential (in relation to the

hedonic tone, the level of pleasure, or displeasure, that an odour creates) and

nature of the odour emission source (e.g. land preparation, aircraft movements),

the pathway for odour flux to receptor (e.g. distance and direction in relation to

prevailing wind direction), and analysis of odour complaints received in relation to

present operations. The assessment has been carried out in accordance with

IAQM guidance (2018), which is considered to represent best practice.

7.4.5 Hedonic tone is scored on a nine-point scale ranging from very pleasant (score of

+4, e.g. bakery smell) through 0 (neutral – neither offensive nor inoffensive) to

highly unpleasant (score of -4, e.g. rotting flesh).

7.4.6 There are no prescribed distance criteria in relation to odour emissions. Based on

professional judgement and supported by odour complaint data, therefore, this

assessment has considered impacts within each community area, on the basis of

distances from sources, which are considered to be excavated landfill sites during

construction and emissions from the North West Runway and associated stands

and taxiways during the operational phase of the DCO Project. The following

distance bands have been used to define the effectiveness of the pathway:

1. Receptors within 350m of the source

2. Receptors 350m-1km from the source

3. Receptors over 1 km from the source.

Assessment against Air Quality Objectives

7.4.7 Atmospheric dispersion modelling to predict pollutant concentrations has been

carried out for two separate model domains in order to focus the assessment on

the determination of likely significant effects:

1. The Core AQO Assessment Area is where pollutant concentrations have been

predicted for consideration against the AQOs at a selection of representative

receptors. Previous dispersion modelling studies that have been carried out,

including those undertaken on behalf of Heathrow (Amec, 2014) and by the

Airports Commission (Jacobs, 2015), show that this area includes the locations

where changes in local air quality (due to airfield, aircraft and road traffic

emissions) are likely to be greatest. The extent has also been determined on



the basis of community areas in which the magnitude of impacts has been

assessed. This is shown in Figure 7.1, Volume 2.

2. At receptors on specific road links outside of the Core AQO Assessment Area

where an initial assessment indicates that significant effects are possible.

These links have been determined using a tiered assessment approach

(described in Section 7.7) which takes account of changes in the number of

road traffic movements and the relative emissions in each assessment year. In

respect of emissions from aircraft, aircraft on approach and departure from

Heathrow have a limited impact on ground-level pollutant concentrations

beyond the Airport boundary, as aircraft are so high that emissions are diluted

by atmospheric diffusion before reaching the ground. Impacts outside of the

Core AQO Assessment Area will therefore be dictated by potential changes in

the number of airport-related road traffic movements and their associated

emissions. Impacts in relation to changes to pollutant concentrations smaller

than those reported in this assessment across a wider area are discussed in

Chapter 12.

7.4.8 At the initial stage of the tiered assessment approach, road links on the Highways

England Strategic Road Network outside of the Core AQO Assessment Area have

been considered to be potentially affected by the DCO Project if any of the

following criteria detailed in the DMRB (Highways Agency, 2007) apply:

1. Daily traffic flows will change by 1,000 Annual Average Daily Traffic (AADT) or

more

2. HDV flows will change by 200 AADT or more

3. Daily average speed will change by 10km/hr or more

4. Peak hour speed will change by 20km/hr or more.

7.4.9 At the initial stage of the tiered assessment, road links on the urban road network

(all other roads) outside of the Core AQO Assessment Area have been considered

to be potentially affected by the DCO Project if any of the following criteria detailed

in the EPUK/IAQM guidance (2017) apply:

1. A change of Light Duty Vehicle (LDV) flows (which includes cars) of:

a. More than 100 AADT within or adjacent to an AQMA

b. More than 500 AADT elsewhere.

2. A change of Heavy Duty Vehicle (HDV) flows of:

a. More than 25 AADT within or adjacent to an AQMA

b. More than 100 AADT elsewhere.



7.4.10 Further details on road traffic modelling (which has provided the vehicle data that

have been used to determine if the criteria have been met) can be found in

Chapter 19: Transport network users.

Assessment of compliance with EU limit values

7.4.11 Road links where compliance with EU limit values is assessed are considered

separately.

7.4.12 NO2 concentrations have been considered at all key PCM assessment locations

within the Core AQO Assessment Area that has been defined in Section 7.4.

Additional PCM locations on the A4 and A40 between the Airport and Central

London where any changes in road traffic could potentially affect the compliance

status of the Greater London agglomeration zone (the relevant zone in which

compliance with EU limit values is assessed) have also been considered. The

assessment considers locations assessed in work carried out on behalf of the

Department for Transport (2017). These are shown in Figure 7.2, Volume 2. The

assessment methodology focuses on the increment in road traffic related pollutant

concentrations at PCM locations as a result of the DCO Project.

Temporal scope

Introduction

7.4.13 The DCO Project will be developed in a phased approach meaning that in some

periods and/or some locations both construction and operational activities will take

place in parallel. Three phases have been identified to broadly correspond with the

most prevalent activities that will arise as a result of the DCO Project.

7.4.14 A number of years have been selected for assessment within each phase, the

approach for which is described in Chapter 5: Approach to the EIA.

7.4.15 The assessment of air quality and odour assesses the following years for this

PEIR:

Phase 1 (c. 2022 – 2026)

1. c.2022-2026 – assessment of construction dust risk has been carried out for each

half year time slice to provide information on the ongoing construction activities

through the phase.

2. 2022 – first year of capacity release of additional ATMs and year in which enabling

works and construction sites are established. Dispersion modelling has been

carried out to predict pollutant concentrations at sensitive receptors in this year as

concentrations are expected to be at their highest in the phase as road traffic

emission factors and background pollutant concentrations are expected to decrease



each year. Emissions from construction traffic and ongoing operation are included

in the assessment.

Phase 2 (c. late 2026 – 2033)

1. 2027 – the first full calendar year when the North West Runway is operational.

During this year construction activities will be ongoing, although construction traffic

is not accounted for in the current version of the road traffic model, however the

likelihood of significant effects is not expected to differ from that presented in this

assessment as construction traffic volumes will be substantially lower than during

the earthworks peak. Construction traffic during Phase 2 will be accounted for in the

ES. Dispersion modelling has been carried out to predict pollutant concentrations at

sensitive receptors in this year. Pollutant concentrations at sensitive receptors are

expected to be higher than subsequent years despite increases in ATMs as road

traffic is the major determining factor of concentrations at roadside locations. Road

traffic emission factors and background pollutant concentrations are expected to

decrease each year. Assessment of construction dust risk has been carried out for

this year.

2. 2030 – The first date which applies for the ANPS surface access targets. Dispersion

modelling has been carried out to predict pollutant concentrations at sensitive

receptors in this year in order to demonstrate the impacts of the progressive

development of infrastructure.

Phase 3 (c. 2034 – 2050)

1. 2035 – referred to as the ANPS capacity year, where the annual number of ATMs at

the Airport is assumed to reach 740k. As with Phase 2, construction traffic is also

not accounted for in the current version of the road traffic model, but will be

accounted for in the ES. Dispersion modelling has been carried out to predict

pollutant concentrations at sensitive receptors in this year. The assessment uses

the latest available year of published road traffic emission factors and background

pollutant concentrations (2030). Therefore this will represent a worst-case

assessment for Phase 3 in terms of pollutant concentrations at receptors. Vehicle

emissions and background pollutant concentrations are expected to decline further

after 2030 as low and zero emissions technologies permeate the road fleet; this is

not accounted for in the calculation of emissions and subsequent dispersion

modelling for 2035.

2. 2050 – Year of maximum capacity, where the annual number of ATMs at the Airport

reaches 756k. Impacts in this year are considered qualitatively as road traffic

emission factors and background pollutant concentrations are only available up to

2030 and, therefore, it is not considered possible to make robust predictions for

2050.



Receptors

7.4.16 The spatial and temporal scope of the assessment enables the identification of

receptors which may experience a change as a result of the DCO Project.

7.4.17 Defra guidance on LAQM (LAQM.TG(16)) makes clear that exceedances of the

health-based AQOs should be assessed at outdoor locations where members of

the general public are regularly present over the averaging time of the objective.

Workplaces are excluded, as explained in Table 7.4, which provides an indication

of those locations that may or may not be relevant for each averaging period.

7.4.18 Where detailed assessment has been undertaken (within the Core AQO

Assessment Area and in other discrete additional areas where traffic data

indicates that detailed assessment is required) pollutant concentrations have been

modelled at a selection of relevant receptors to assess effects within each

community area.

7.4.19 Model outputs have also been interpolated to determine the total concentrations,

changes in concentrations and impact descriptors at all residential addresses in

the Ordance Survey AddressBase data within the Core AQO Assessment Area.

This process has enabled values to be determined for 145,452 residential

properties. It is worth noting that the location attributes of AddressBase address

points are not necessarily on the façade of properties facing the emission sources

and are generally at the centre of the relevant building. The results that would be

determined if exact property façade locations were used would not be expected to

be significantly different from those presented in this assessment.

7.4.20 The list of receptors will be kept under review as supplementary information is

obtained during baseline surveys and other forms of data collection by other

aspects and will be reflected in the final ES.

7.4.21 Where emissions that have a potential to cause a nuisance are considered (dust

and odour), commercial premises are also considered as sensitive receptors.

Table 7.4: Examples of where the air quality objectives should apply (Defra, 2016)

Averaging Period Objectives should apply at: Objectives should generally not

apply at:

Annual mean All locations where members of the

public might be regularly exposed

Building facades of offices or other

places of work where members of

the public do not have regular

access.

Building facades of residential

properties, schools, hospitals, care

homes etc.

Hotels, unless people live there as

their permanent residence.

Gardens of residential properties.



Averaging Period Objectives should apply at: Objectives should generally not

apply at:

Kerbside sites (as opposed to

locations at the building façade), or

any other location where public

exposure is expected to be short

term.

24-hour mean and 8-hour mean All locations where the annual

mean objectives would apply,

together with hotels.

Kerbside sites (as opposed to

locations at the building façade), or

any other location where public

exposure is expected to be short

term. Gardens or residential properties.

1-hour mean All locations where the annual

mean and 24 and 8-hour mean

objectives would apply.

Kerbside sites where the public

would not be expected to have

regular access.

Kerbside sites (e.g. pavements of

busy shopping streets).

Those parts of car parks, bus

stations and railway stations etc.

which are not fully enclosed, where

the public might reasonably be

expected to spend one hour or

more.

Any outdoor locations at which the

public may be expected to spend

one hour or longer.

Identification of potential effects

7.4.22 Potential effects on air quality and odour receptors that have been scoped in for

assessment are summarised in Table 7.5.

Table 7.5: Potential effects on air quality and odour receptors scoped in for further assessment

Receptor Activity Effect

Residential properties, schools,

medical facilities, commercial

sites, businesses.

Land preparation (including

excavation and earthworks).

Emission of dust causing loss of

amenity at sensitive receptors near to

work sites and haul roads.



sites, businesses.

Emission of odours causing loss of


work sites.



Construction site (including

laydown areas, Heathrow

Emission of dust causing loss of




Receptor Activity Effect

sites, businesses. colleague facilities etc.),

earthworks, North West

Runway and

terminal/satellite

development.

work sites and haul roads.


medical facilities.

Emissions from construction vehicles

and plant through fuel combustion that

increases concentrations of pollutants

which may lead to an effect on human

health (NO2 and PM).


medical facilities.

Construction vehicle

movements using the public

highway (incl. workforce

travel) or temporary on-site

haul routes.

Emissions from construction vehicles

through fuel combustion and brake/tyre

wear that could increase concentrations

of pollutants which thereby have an

effect on human health (NO2 and PM).


medical facilities.

Aircraft movements

associated with the North

West Runway and taxiways

(including in Landing and

Take-Off (LTO) cycle).

Increased emissions from aircraft

through fuel combustion that could

increase concentrations of pollutants

that could affect human health (NO2,

PM and SO2).



sites, businesses.

Increased emissions of odour from

aircraft fuel, aircraft operation and

airfield activity causing loss of amenity

at sensitive receptors.


medical facilities.

Land based activities in

support of airport operation

(including presence of

workforce, use of vehicles

airside and Ground Support

Equipment, management of

waste, rail freight etc.)

Increased combustion emissions as a

result of increased air transport

movements that could increase

concentrations of pollutants having an

effect on human health (NO2 and PM).



sites, businesses.

New/expanded waste

facilities.

Emission of odours causing loss of

amenity at sensitive receptors.


medical facilities.

Vehicular traffic associated

with the Airport, including

that in car parks (including

Heathrow colleagues and

passengers and freight

vehicles).

Increased emissions from vehicles on

public highways that may increase

concentrations of pollutants and thereby

have an effect on human health (NO2

and PM).

Effects no longer being considered

7.4.23 The following effects have been scoped out of the assessment for the reasons

summarised in Table 7.6.



Table 7.6: Effects no longer considered in this PEIR

Activity Effect Receptor Justification

Aircraft

movements

associated with

the North West

Runway and

taxiways

(including in LTO

cycle)

Increased

emissions from

aircraft through

fuel combustion

that could

increase

concentrations

of O3

Residential

properties,

schools,

medical

facilities

PSDH (Department for Transport, 2006) was set up by the Department for Transport in 2005

to investigate the environmental effects of a North West Runway at Heathrow. It convened a

panel of experts in air quality, aircraft technology, airport operations and related fields to

develop a best practice methodology for assessing the air quality impacts of a North West

Runway at Heathrow. PSDH is considered to be best practice in the assessment of air quality

around airports. PSDH sets out that O3 was not considered to be a priority pollutant. The

Technical Panels did not consider modelling the impact of Heathrow emissions on O3

concentrations to be a priority area (Chapter 1 of the PSDH report). Where O3 was included

in PSDH deliberations it was because of its role in converting emissions of NO to NO2

(Chapter 2 of the PSDH report). It was also noted that O3 is formed at a regional scale on

timescales of hours or even days, from reactions involving VOCs, NOx and sunlight (Chapter

4 of the PSDH report). The formation of elevated concentrations of O3 is relatively infrequent,

occurring principally on hot, sunny, summer days, and well downwind of the source of the

pre-cursor emissions (AQEG, 2009). More locally, and on all other days, emissions of NOx

from the Airport will lead to a reduction in O3 concentrations (due to the reaction of O3 with

NO).

It is for these reasons that emissions associated with the North West Runway will not give

rise to elevated O3 concentrations within around 50km of the Airport. This is the basis of

scoping out impacts of the DCO Project on O3 concentrations. This conclusion will apply to

all precursor emissions associated with the Airport, from whatever source.

As noted above, the link between emissions and O3 concentrations will relate to the total

Airport related emissions of NOx and VOCs. However, concern is raised in the Scoping

Opinion that the ‘land based activities’ are not detailed and that there is a ‘potential for

sources of ozone arising from sources such as new generation plant’.

Any new emissions from land-based activities, including new generation plant, will not in

themselves be a source of O3 affecting the local environment. As set out in the previous

paragraph, O3 is a secondary pollutant formed well downwind of the source on days when

temperatures are high and sunlight is present. Land-based activities will include the on-airport

Ground Support Equipment (GSE) as well as heating plant. Detailed emission inventories




have previously been prepared for Heathrow showing the contributions of the different

sources to NOx emissions. The latest one available is for 2013 emissions (Ricardo, 2015). It

gives the following split for airport related NOx emissions: aircraft (4,290 te/yr), land-based

activities (270 te/yr) and road traffic (400 te/yr), giving a total of 4960 te/yr. Heating plant are

responsible for 85 te/yr, which represents 31% of the NOx emissions from land-based

activities. In turn, the land-based activities are only responsible for 5% of the total NOx. While

these numbers are for existing Heathrow operations, it is anticipated that patterns will be

similar for the emissions associated with the North West Runway; aircraft will remain the

dominant source. On this basis, if the ‘total’ NOx emissions have been scoped out in terms of

potential O3 impacts, then the same will apply to emissions from the land-based activities,

including new generation plant, which will be a small fraction of the total emissions.

Aircraft

movements

associated with

the North West

Runway and

taxiways

(including in LTO

cycle)

Increased

emissions from

aircraft through

fuel combustion

that could

increase

concentrations

of secondary

particulates

Residential

properties,

schools,

medical

facilities

Secondary PM arises from reactions of gases in the atmosphere. The principal contributions

from Heathrow to secondary PM are from emissions of NOx and to a lesser extent SO2

reacting with ammonia (NH3), which mainly arises from agricultural sources, to give inorganic

PM (ammonium nitrate and ammonium sulphate). There is also a contribution from VOCs

reacting and condensing to form organic PM. These reactions take place slowly in the

atmosphere, with a time frame of hours to days (Laxen et al, 2010), thus emissions of NOx,

SO2 and VOCs from Heathrow will only contribute to secondary PM many kilometres

downwind of Heathrow. It is for this reason that secondary PM is considered to be a regional

pollutant and concentrations are relatively uniform over large areas.

Across London, background annual mean concentrations of secondary PM2.5 in 2016, as

published by Defra, fell in the range 4.03 to 4.56 µg/m3 (Defra, 2018b). This covers both

secondary inorganic and secondary organic PM. The nitrate component is likely to be of the

order of 1.5 µg/m3 (as ammonium nitrate), sulphate around 2 µg/m3 (as ammonium sulphate),

and organic particles of the order of 1 µg/m3 (Laxen et al, 2010). These nitrate, sulphate and

organic components will arise from emissions of NOx, SO2 and VOCs from sources

throughout the UK and to some extent emissions from sources across continental Europe

(especially northern Europe); due to the slow formation of secondary particles, emissions

from local sources will make a minor contribution to these local background concentrations.

NAEI provides information on UK emissions of NOx, SO2 and VOCs for 2016 (the most

recent year). Total NOx emissions were 881 ktonnes (kt), for SO2, 167 kt, and for VOCs (non-




methane), 119 kt. Of these amounts 11.3 kt, 1.4 kt and 1.74 kt respectively are attributable to

civil aircraft in the landing and take-off cycle from all UK airports, with emissions from support

vehicles included in the figure for VOCs; representing 1.28%, 0.84% and 1.46% respectively.

Taking into account that Heathrow emissions are only part of the total, that the background

concentrations are not due just to UK emissions, and that local emissions will not form

secondary particles in the near field, it is reasonable to conclude that current Heathrow

emissions will contribute no more than 1% to the secondary PM across London. In other

words, less than around 0.015 µg/m3 of the background ammonium nitrate, 0.02 µg/m3 of the

background ammonium sulphate and 0.015 µg/m3 of the background secondary organic PM

in London will relate to current Heathrow emissions, with the additions due to the North West

Runway being even smaller.

These contributions are considered to be negligible, representing less than around 0.06% to

0.08% of the annual mean AQO for PM2.5 of 25 µg/m3. With the DCO Project, contributions

will remain negligible. It is thus considered appropriate to scope out the contributions of

secondary PM to the calculated PM concentrations within the air quality assessment. The

only potentially significant effects in relation to PM are considered likely to be those related to

human health. Effects are assessed in relation to AQOs and EU limit values established for

PM. The assessment involves calculating the changes in concentrations at sensitive

locations.



7.5 Embedded environmental measures

7.5.1 The DCO Project will consider a number of environmental measures to avoid or

reduce likely significant effects. This approach is described in Chapter 5. Some of

these environmental measures have been embedded into the DCO Project design.

Those embedded environmental measures that influence the assessment of air

quality and odour are set out in Table 7.7.

7.5.2 Good practice environmental measures would occur with or without input from the

EIA feeding into the design process. They include actions that would be

undertaken to meet other existing legislative requirements, or that are considered

to be standard practices. These will be a continuation of the measures detailed in

the current Emissions Strategy and Action Plan (Heathrow, 2018). Those good

practice environmental measures that influence the assessment of air quality and

odour are set out in Table 7.8.



Table 7.7: Summary of the embedded environmental measures in the design and how these influence the air quality and odour assessment

Receptor Changes and effects Embedded measures and influence on assessment

Residential

properties,

schools,

medical

facilities

Increased emissions from

vehicles on public highways that

may increase concentrations of

pollutants and thereby have an

effect on human health (NO2 and

PM)

The Surface Access Proposals (SAP) document submitted as part of the Airport Expansion

Consultation (June 2019) sets out how access to the Airport by all travel modes will be managed to

meet targets set out in the ANPS (Department for Transport, 2018), as well as fulfilling

Heathrow’s pledge not to increase airport-related traffic through expansion. The targets set out in

the ANPS are:

1. To increase the proportion of journeys by passengers made to the airport by public transport,

cycling and walking to achieve a public transport mode share of at least 50% by 2030 and at

least 55% by 2040; and

2. From a 2013 baseline level, achieve a 25% reduction of all staff car trips by 2030, and a

reduction of 50% by 2040.

Residential

properties,

schools,

medical

facilities






PM)

The SAP document includes proposals for a road user charging strategy which sets out:

1. Proposals for a Heathrow Ultra Low Emissions Zone (HULEZ), to be introduced following the

grant of a DCO. This would broadly mirror the standards of the current London Ultra Low

Emissions Zone and would levy a charge on any passenger cars, taxis and private hire

vehicles that do not comply with emissions standards (Euro 4 for petrol cars and Euro 6 for

diesel). The impact of the HULEZ has not been assessed in the dispersion modelling carried

out for this assessment, but will be considered in the ES; and

2. Proposals for the introduction of a vehicle access charge as the North West Runway is

opened, to encourage passengers to travel by other modes.

Residential

properties,

schools,

medical

facilities






PM)

The SAP document includes public transport proposals which set out how the usage of existing

and committed public transport to the airport will be increased through measures such as:

1. Improved ticketing;

2. Cheaper fares on the Heathrow Express and earlier and later services;

3. The new bus and coach services Heathrow is proposing to support;

4. Bus and coach priority measures;

5. Support to the DfT and Network Rail to bring forward the proposed Western and Southern rail

schemes and provision of additional infrastructure at both the Terminal 5 and the CTA rail

stations to support this;




6. Provision of additional capacity at both the Heathrow Central Bus Station and Terminal 5 Bus

Station to support new bus and coach routes.

Residential

properties,

schools,

medical

facilities






PM)

The SAP document includes proposals in relation to colleague travel which set out the measures

that will be introduced to encourage increased pedestrian and cycle access and use of public

transport by colleagues, such as:

1. Proposals to develop a ‘hub and spoke’ network of cycle routes;

2. Improvements to cycling facilities at the airport and on key routes from the airport to the

surrounding area;

3. The introduction of a needs-based framework for allocation of colleague car parking spaces,

in the context of colleague car parking provision being reduced.

Residential

properties,

schools,

medical

facilities






PM)

The SAP document includes car parking proposals detailing how colleague vehicle reduction

targets will be met (in association with the public transport proposals and colleague travel

proposals) and passenger parking will increase, though not in line with growth in passenger

numbers. Parking will be consolidated in three major Parkways:

1. Consolidated colleague and passenger parking in a Southern Parkway with good access from

the M25 to serve the Western Campus (Terminal 5 and Terminal 5X);

2. Consolidated colleague and passenger parking in a Northern Parkway with good access from

the M4 to serve the Eastern Campus (Terminal 1 and Terminal 2); and

3. Additional parking to support Terminal 4, accessible via Junction 14 of the M25 and the

Southern Perimeter Road.

Car Hire and taxi and private hire waiting areas (the ‘Taxi Feeder Park’ and ‘Authorised Vehicle

Area’) are proposed to be consolidated in an intensified multi-storey car park on the former

Terminal 4 Landside Terminal Car Park, able to efficiently service both the western campus,

Terminal 4 and CTA (via the proposed Southern Road Tunnel).

Residential

properties,

schools,

medical

facilities,

commercial

sites,

Increased emission from aircraft

through fuel combustion that

could increase concentrations of

pollutants that could affect

human health (NO2, PM and

SO2) and emissions of aviation

fuel odour

The taxiway system serving the North West Runway and expanded airport has been designed to

facilitate efficient airfield operations.

Wherever practicable, and consistent with airspace operations, arrivals and departures will be

allocated to use the runway closest to the terminal they are using to minimise taxi distances and

associated emissions. This runway allocation preference will be applied to each of the 8 modes of

operation. In addition, taxiways will be used in such a way that the airfield operates efficiently.




businesses Departing aircraft will access the runway via one of several Runway Access Taxiways (RATs),

provided at each runway end, enabling a controlled and optimal departure stream.

Arriving aircraft will use one of several Rapid Exit Taxiways (RETs) that will be provided on each

runway, minimising the length of time an aircraft occupies the runway and allowing an efficient

arrival stream.

Residential

properties,

schools,

medical

facilities






PM)

As far as reasonably practicable, the alignments of diverted roads outside the airport boundary

seek to maximise separation between the highway and receptors. This reduces the risk of adverse

impacts of road traffic emissions on pollutant concentrations.

Residential

properties,

schools,

medical

facilities






PM)

Heathrow will ensure that all new roads and junctions will be designed in such a way as to take

cognisance of all travellers, including non-motorised users (NMU). Improvements for NMUs such

as cycle lanes, wayfinding, controlled crossing points and footway improvements will be included

where appropriate.

Residential

properties,

schools,

medical

facilities,

commercial

sites,

businesses

Fugitive emission of odour during

transfer of fuel

Fuel farms are and will continue to be supplied directly from the CLH pipeline system, preventing

fugitive odour emissions from delivery of fuel into the tanks.

Fuel farms are located within the airfield, either downwind of or a significant distance from

receptors. This reduces the risk of adverse impacts on the amenity of receptors due to associated

odour.

Residential

properties,

schools,

medical

facilities,






Heathrow will provide Fixed Electrical Ground Power (FEGP) for parked aircraft on new pier served

and remote stands.

This will minimise the need for aircraft to use their Auxiliary Power Units (APU) whilst on-stand.




commercial

sites,

businesses


fuel odour

Residential

properties,

schools,

medical

facilities,

commercial

sites,

businesses







fuel odour

Heathrow will provide Pre-Conditioned Air (PCA) for new aircraft stands, where there is a clear

business case and environmental benefit, given the intended occupancy of the stand.

Residential

properties,

schools,

medical

facilities


vehicles on highways that may

increase concentrations of



PM)

The design includes an improved airside road system with few taxiway crossings and vehicle

conflict points, to reduce journey times and associated emissions.

Residential

properties,

schools,

medical

facilities

Increased combustion emissions

from GSE as a result of

increased air traffic movements

that could increase

concentrations of pollutants

having an effect on human health

(NO2 and PM)

Heathrow will provide infrastructure to facilitate the use of low emission airside equipment, such as

electric vehicles. This includes for example, the provision of charging points within GSE

compounds.

Residential

properties,

schools,

medical

facilities






PM)

Heathrow will provide infrastructure for charging electric and hybrid vehicles in consolidated car

park areas, to support the use of Ultra Low Emission Vehicles (ULEV).

Residential Increased combustion emissions Heathrow will develop and implement an ultra-low emissions zone for airside vehicles by 2025, to




properties,

schools,

medical

facilities

from GSE as a result of

increased air traffic movements

that could increase


having an effect on human health

(NO2 and PM)

improve the emissions performance of the airside vehicle fleet.

Residential

properties,

schools,

medical

facilities






SO2)

Heathrow will review the tariff structure (including landing charges) to ensure that airlines are

encouraged to use lower emitting aircraft. Charges relate to kg of NOX emitted per flight.

Residential

properties,

schools,

medical

facilities






SO2)

In addition to providing infrastructure to facilitate the adoption of operational efficiency measures,

Heathrow will continue to implement operational measures to reduce aircraft emissions on the

ground. We will work with NATS and airlines to increase the application of reduced engine taxiing

and reduced APU use where practicable and ensure that the airfield operates efficiently.

Residential

properties,

schools,

medical

facilities






PM)

The railhead is intended to be the principal import facility for bulk materials, primarily aggregates,

sand and cement for concrete production. Other materials and containerised goods for construction

purposes may also be delivered by rail. Rail would also be used to export materials off-site where

practicable. This will reduce the need for road vehicle trips and associated emissions.



Table 7.8: Summary of the good practice environmental measures and how these influence the air quality and odour assessment

Receptor Changes and effects Good practice measures and influence on assessment

Residential

properties,

schools,

medical

facilities,

commercial

sites,

businesses

Fugitive evaporative emission

from occasional spillages of

aviation fuel

The current procedure of a rapid response to fuel spillages will be maintained. Spillages are bunded

temporarily and then soaked- or vacuumed-up, to minimise exposure time to the atmosphere.

Residential

properties,

schools,

medical

facilities


vehicles on public highways

that may increase


and thereby have an effect on

human health (NO2 and PM)

Where construction freight is brought to site by road, it would be managed through adherence to

dedicated routes and specific arrival slots. Delivery management systems would allocate pre-booked

delivery slots to suppliers, allowing the time of each delivery to be controlled, thus managing the flow

of vehicles arriving at the site entrances. This would also allow for the spread of deliveries throughout

the day, and so minimise the impact of construction traffic on the road network especially during peak

times.

Residential

properties,

schools,

medical

facilities



that may increase




Heathrow will prepare and implement a Construction Traffic Management Plan (CTMP). The

Preliminary Outline CTMP (POCTMP) has been submitted as part of the Airport Expansion

Consultation (June 2019).

The CTMP will detail construction traffic management measures that will be implemented during the

construction of the DCO Project, and will include controls on construction vehicle types, hours of site

operation and delivery routes for goods vehicles.

The objective of the CTMP is to reduce potential construction traffic impacts on the highway network

and transport network users as a result of the scheme, as far as reasonably practicable. The CTMP

will include details of proposed temporary or permanent closures or diversions of roads, public rights

of way or accesses.

A draft CTMP will be submitted with the DCO application. The appointed lead contractor will be

responsible for the development, implementation and monitoring of the CTMP in consultation with the

highway and traffic authorities and relevant stakeholders.




Residential

properties,

schools,

medical

facilities



that may increase




Heathrow will prepare and implement a Construction Workforce Travel Plan (CWTP). The Preliminary

Outline CWTP (POCWTP) has been submitted as part of the Airport Expansion Consultation (June

2019).

The CWTP will detail measures to encourage the use of sustainable travel modes to reduce the

impact of workforce travel on local residents and transport network users.

A draft CWTP will be submitted with the DCO application. The appointed lead contractor will be

responsible for the development, implementation and monitoring of the CWTP in consultation with

relevant authorities and stakeholders.

Residential

properties,

schools,

medical

facilities,

commercial

sites,

businesses

Emission of dust causing loss

of amenity at sensitive

receptors near to work sites

and haul roads

The layout of construction sites will be planned to ensure that where reasonably practicable,

machinery, plant and dust-causing activities are situated away from sensitive receptors.

Residential

properties,

schools,

medical

facilities

Increased combustion

emissions that may increase




Measures will be implemented to reduce potential emissions from construction plant and vehicles,

including:

1. Consideration will be given to the use of low emission plant and machinery, including the use of

electric vehicles where reasonably practicable

2. All Non-Road Mobile Machinery (NRMM) will use Ultra-Low Sulphur Diesel (ULSD) and will be

required to meet Stage IIIB of EU Directive 97/68/EC and its subsequent amendments (giving

regard to the GLA exemptions and retrofit policy)

3. All construction vehicles will be required to meet minimum vehicle emission standard engines.

HGVs will be required to comply with Euro VI emission standards. Petrol LDVs will be required

to comply with Euro 4 emission standards and Diesel LDVs will be required to comply with Euro

6 emission standards.

Residential

properties,

schools,

Emission of dust from

material transportation and

storage causing loss of

Measures will be implemented to reduce dust emissions through the effective transportation and

storage of materials, including:

1. Construction vehicles delivering and/ or removing materials or loads from construction sites via




medical

facilities,

commercial

sites,

businesses

amenity at sensitive receptors

near to work sites and haul

roads

the highway will be required to be covered by a fixed cover or sheeting

2. Where reasonably practicable, stockpiles and mounds will be kept away from sensitive

receptors, water courses and surface drains and located to consider the predominant wind

direction

3. Appropriate dust suppression measures (e.g. covering, fencing, watering, seeding) will be

employed where material stockpiles have the potential to generate dust.

Residential

properties,

schools,

medical

facilities,

commercial

sites,

businesses


excavations and earthworks

causing loss of amenity at

sensitive receptors near to

work sites and haul roads

Measures will be implemented to reduce dust emissions from excavations and earthworks activities,

including, as appropriate:

1. Topsoil will be stripped as close as reasonably practicable to the period of excavation or other

earthworks activities

2. Drop heights from excavators to vehicles involved in the transport of excavated material will be

kept to the reasonably practicable minimum

3. Soil spreading, seeding, planting or sealing of completed earthworks will be undertaken as soon

as reasonably practicable following completion of the earthworks.

Residential

properties,

schools,

medical

facilities,

commercial

sites,

businesses

Emission of dust through

resuspension from on-site

construction traffic routes

causing loss of amenity at

sensitive receptors near to

work sites and haul roads

The management of on-site construction traffic routes will include the following measures, where

relevant:

1. Ongoing maintenance to limit dust emissions as far as reasonably practicable, considering the

intended level of traffic movements by the main contractors

2. The regular and timely inspection of on-site construction traffic routes, essential for monitoring the

need for repair and recovery, including maintenance of a smooth-running surface and timely

repair of potholes

3. The provision of areas of hard surfacing and hard standing at the approach to site access and

egress points for use by waiting construction vehicles;

4. The enforcement of speed limits on on-site construction traffic routes for safety reasons and to

suppress dust emissions

5. Methods to clean and supress dust on on-site construction traffic routes and in designated vehicle

waiting areas, such as watering.

Residential

properties,

schools,

medical

facilities



that may increase



In order to reduce the effects of construction traffic utilising the public highway, Construction Logistics

Plans (CLPs), will be prepared in consultation with the relevant highway authorities. Specific

measures in the CLPs will include, where reasonably practicable:

1. Priority given to transport of materials by rail

2. Selection of designated routes to consider areas of poor air quality




human health (NO2 and PM) 3. Selection of designated routes that, where possible, minimise the distance travelled on local

roads

4. Consolidation of freight to reduce the number of movements

5. Provision of HGV parking areas to reduce queuing or waiting on the public highway

6. Timing of deliveries and movements to avoid worsening congestion where practicable

7. Monitoring and enforcement to ensure that contractors use designated routes only.

Residential

properties,

schools,

medical

facilities,

commercial

sites,

businesses


demolition activities causing

loss of amenity at sensitive


and haul roads

Measures will be implemented to reduce dust emissions from demolition, including:

1. Enclosing or shielding rubble chutes and/or using water to suppress dust emissions from

equipment

2. Spraying buildings and/or structures to be demolished with water or screening as necessary, prior

to and during demolition

3. Programming activities that are close to schools or routes to school to avoid times where children

are likely to be nearby.

Residential

properties,

schools,

medical

facilities,

commercial

sites,

businesses

Fugitive emission of odour

during the relocation of

historic and authorised landfill

sites causing loss of amenity

at sensitive receptors near to

work sites

Odorous materials may be excavated during the DCO Project, containing volatiles that may give rise

to odour impacts. The following measures will be implemented:

1. Contaminated and non-contaminated materials will be stockpiled separately following

excavation

2. Early identification of contaminated material which could generate an odour issue

3. Taking measures to control the emission of any odours (e.g. covering up/tenting any potentially

odorous materials uncovered where appropriate)

4. Locating stockpiles of contaminated materials as far away from residential receptors as

practicable

5. Careful programming to limit the duration of work with potential to generate odour nuisance

6. Removing odour generating material sources in a timely fashion to limit the formation of odours

7. Where odour forming materials are encountered and cannot be removed or avoided, the

spraying with an approved oxidising agent will be undertaken if appropriate to control the

potential for release of odour

8. Use of an odour guard or masking agents will also be considered in situations where the risk of

odour release cannot be eliminated or controlled.

Residential

properties,

Emission of dust associated

with activities during the

Monitoring will be carried out in accordance with the Mayor of London’s Supplementary Planning

Guidance on the Control of Dust and Emissions from Construction and Demolition (2014) and in




schools,

medical

facilities,

commercial

sites,

businesses

construction phase causing



consultation with all relevant local authorities. At all sites, as a minimum, the following measures will

be carried out:

1. Site inspections covering the establishment of operation of the construction site

2. Visual assessment of any particulate matter and air pollution generated in areas adjacent to the

construction-site; - Inspection of the maintenance schedules for construction vehicles, plant and

machinery

3. Inspection processes relating to the level of traffic movements, use and condition of on-site

construction traffic routes

The monitoring programme will include continuous automatic monitoring of PM10. Trigger levels will

be set, above which investigation will be required. For automatic PM10 measurement, this trigger level

will be 250µg/m3 in accordance with the Mayor’s SPG. In the event that the trigger level is breached,

activities and any visible emissions will be investigated and measures put in place to limit effects.

Heathrow Expansion PRELIMINARY ENVIRONMENTAL INFORMATION Report: Chapter 7: Air quality and odour


7.6 Methodology for baseline data gathering

7.6.1 Baseline data collection has been undertaken to obtain information for the study

areas described in Section 7.4. Section 7.9 sets out baseline data currently

available from the study area/s.

Desk study

7.6.2 A summary of the organisations that have supplied data, together with the nature

of that data is outlined in Table 7.9.

Table 7.9: Data sources used to inform the air quality and odour assessment

Organisation Data provided Data time

period

Date received

Heathrow Airwatch website

(Heathrow Airwatch, 2018)

Data from automatic air quality

monitoring stations in the vicinity

2012-2017 2018-2019

LPAs (London Borough of Ealing,

London Borough of Hillingdon,

London Borough of Hounslow,

Slough Borough Council, South

Bucks District Council,

Spelthorne Borough Council,

Runnymede District Council, and

Royal Borough of Windsor and

Maidenhead)

NO2 diffusion tube data collected

as part of the LAQM regime

obtained from publicly available

reports from each LPA.

2012-2017 2018-2019

Defra Data from the assessment of

compliance with EU limit values

carried out by Defra. In association

with the UK plan for tackling

roadside nitrogen dioxide

concentrations (Defra, 2017a), NO2

concentrations were modelled

using the PCM model with a 2015

base-year for several different

future scenarios to consider the

measures required to achieve

compliance. The 2017 base-year

update has also been considered.

2015-2030 2019

Defra Estimates of background

concentrations for specific

pollutants. These enable

calculation of the contribution of

local sources to total pollutant

concentrations. They provide

information on how pollutant

concentrations change over time

and across a wide area; they also

2015-2030 2019



Organisation Data provided Data time

period

Date received

provide an estimated breakdown of

the relative sources of pollution

(Defra, 2017b).

Odour complaints data Complaints received and logged by

Heathrow in the ‘Aircraft

Emissions’, ‘Health/pollution

Levels’ and ‘Odour’ categories.

2014-2019 2018-2019

7.7 Assessment methodology for PEIR

Assessment methodology evolution

7.7.1 At this stage in the development of the EIA, the DCO Project is still under

development and is the subject of statutory consultation. The likely significant

environmental effects are presented at this preliminary stage. Further,

supplementary assessment work will be undertaken between PEIR and

preparation of the ES that will accompany the application for development consent

for the DCO Project.

7.7.2 The methodology for the ES may therefore develop further from that used for the

PEIR. Anticipated changes in the assessment methodology are summarised in

Table 7.10, with reasons for any likely amendments detailed.

Table 7.10: Assessment methodology for the PEIR and ES

Effect Assessment methodology used for

this PEIR

Assessment methodology to be

used for the ES

Impact of the DCO

Project in relation to

AQOs during

construction and

operation.

Model input data, including road traffic

data and aircraft schedules based on

preliminary information available for

this PEIR.

Geographical extent of Core AQO

Assessment Area focused on a

12x11km area centred on the Airport,

based on expected maximum extent

of potential significant effects.

Detailed dispersion modelling, with

Model input data, including road traffic

data and aircraft schedules will

continue to be refined, and the air

quality assessment will be based on

the final versions of these models,

inputs and assumptions.

Core AQO Assessment Area

expected to remain unchanged, but

additional areas may require

modelling depending on the final road

traffic datasets and the likely changes

in traffic flows on the road network

outside this Core AQO Assessment

Area.

Inclusion of baseline monitoring data



Effect Assessment methodology used for

this PEIR

Assessment methodology to be

used for the ES

verification against continuous

monitoring data from the baseline

years of 2015, 2016 and 2017

calendar years.

Years for quantitative assessment

focused on the first year of

construction activities and the first

year of capacity release of additional

ATMs (2022); the first full calendar

year of three runway operations

(2027); the year that the ANPS

surface access targets are to be met

and to the impact of the progressive

development the Airport infrastructure

(2030); the ANPS capacity year

where the annual number of ATMs is

assumed to reach 740k (2035).

Impacts in years other than 2022,

2027, 2030 and 2035 are assessed

qualitatively.

for 2018 and update of dispersion

model verification to include the 2018

calendar year.

Additional assessment years will be

considered, in order to ensure the full

range of potential impacts are

quantitatively considered, particularly

in the period from 2022 to 2030.

Impact of the DCO

Project in relation to EU

limit values during

construction and

operation.

Assessment of limit value compliance

has been considered through the

application of atmospheric dispersion

modelling within the Core AQO

Assessment Area, and by reference

to the surface access demand

modelling outside the Core AQO

Assessment Area. Future baseline

NO2 concentrations at PCM links are

based on Defra’s projections in the Air

Quality Plan (Defra, 2017a).

The air quality assessment will be

based on what will then be the latest

version of Defra’s projections at PCM

locations. Where demand modelling

does not show that there will be

reductions in traffic flows, and where

changes in traffic flows have the

potential to lead to non-negligible

changes in air quality, dispersion

modelling of discrete PCM road links

will be undertaken to assess the likely

impact on EU limit value compliance.

Impact of the DCO

Project in relation to dust

and odour risk during

construction.

Assessment of construction dust and

odour risk has been carried out

considering the progress of

construction activities through the

phases. The PEIR assessment is

based on the latest understanding of

the infrastructure phasing the

construction methodology.

The construction dust and odour risk

assessment will be updated to reflect

the final phasing of infrastructure and

construction methodology.



Construction assessment methodology

Demolition and construction dust

Overview

7.7.3 The GLA (2014) and the IAQM (2014) have developed guidance regarding the

assessment of the effects of construction on air quality and the determination of

their significance, which have been used to assess construction effects. The

significance of construction effects is assessed by considering the risk of

annoyance due to dust soiling as well as the risk of health effects due to any

significant increases to PM10 or PM2.5.

7.7.4 In the absence of suitable control measures, construction activities can result in

regular and persistent dust emissions, which may affect local amenity and quality

of life. The level of concern amongst local communities, and potential for

annoyance, is related to the existing baseline dust levels, the number and

proximity of residential areas to the site, and the exact nature of the activities

on-site. The degree of actual annoyance would also depend on factors such as the

rate of dust deposition, and the application of environmental measures on site.

7.7.5 Dust complaints are usually associated with periods of peak deposition, occurring

during particular weather conditions. There is a ‘normal’ level of dust deposition in

every community and it is only when the rate of deposition is high relative to the

norm that complaints tend to occur. The guidance sets out the factors influencing

annoyance, which includes the effects of dust on a community. The risk of

demolition and construction activities causing exceedance of PM10 AQOs is also

considered.

7.7.6 Site activities have been divided into four types to reflect their different potential

effects:

1. Demolition – an activity involved with the removal of an existing structure or

structures

2. Earthworks – the processes of soil-stripping, ground-levelling, excavation and

landscaping

3. Construction – an activity involved in the provision of a new structure

4. Vehicle movements – which can cause trackout (the transport of dust and dirt

from the site onto the public road network). This arises when lorries leave site

with dusty materials or transfer dust and dirt onto the road having travelled over

muddy ground on-site.



Dust emission magnitude

7.7.7 The potential dust emission magnitude of the demolition, earthworks and

construction activities were defined for each half year. In accordance with the

IAQM guidance (IAQM, 2014), dust emission magnitude is defined as small,

medium or large, based on the scale of the proposed works. Demolition activities

are defined as large when the total volume of buildings to be demolished is above

50,000 m3. Earthworks activities are defined as large when the total site area is

above 10,000 m2. Construction activities are defined as large when the total

volume of newly constructed buildings is above 100,000 m3. Trackout is defined as

large when there are more than 50 HGV outward movements in one day.

7.7.8 The construction dust assessment has been carried out for individual work areas.

The number of receptors within different distance bands of site boundaries (to

determine the sensitivity of the area) has been counted. The distance bands used

to determine the number of receptors are 20m, 50m, 100m and 350m.

Sensitivity of the area

7.7.9 The sensitivity of area to dust soiling effects on people and properties was defined

using Table 2 of the IAQM guidance on the assessment of dust from demolition

and construction, as represented in Table 7.11.

Table 7.11: Sensitivity of area to dust soiling effects on people and properties

Distance from the source (m)

Receptor sensitivity

Number of receptors

<20 <50 <100 <350

High

(residential

receptors)

>100 High High Medium Low

10-100 High Medium Low Low

1-10 Medium Low Low Low

Medium >1 Medium Low Low Low

Low >1 Low Low Low Low

Trackout may occur 500m from large site as measured from the site exit. The impact declines with distance

from the site and it is only necessary to consider trackout impacts up to 50m from the edge of the road.

7.7.10 The sensitivity of an area to human health effects was defined using Table 3 of the

IAQM guidance, as reproduced in Table 7.12.



Table 7.12: Sensitivity of area to human health impacts

Distance from the source (m)

Receptor sensitivity

Annual mean PM10 concentration

Number of receptors

<20 <50 <100 <200 <350

High

(residential

receptors)

<24 μg/m3 (the concentration band as taken from Defra background maps)

>100 Medium Low Low Low Low

1-100 Low Low Low Low Low

Medium <24 μg/m3 1-10+ Low Low Low Low Low

Low - ≥1 Low Low Low Low Low

7.7.11 Individual receptors have been classified according to the risk of effects (based

upon the scale and nature of the works, plus the proximity to work sites) in

accordance with Tables 6 to 9 of the IAQM guidance.

7.7.12 In accordance with the guidance, the significance of the dust effects has been

considered assuming application of the measures detailed in Section 7.5. The

overall significance of the effects arising from the entire construction phase is

based on professional judgement, taking into account the impacts of each of the

four activity types.

Odour

7.7.13 Unlike other forms of air pollution, odours are not generally additive. This reflects

the way in which the brain responds to odour. The human brain has a tendency to

‘screen out’ those odours which are always present or those that are in context to

their surroundings. For example, an individual is more likely to be tolerant of an

odour from a factory in an industrial area than in the countryside. The human brain

will also develop a form of acceptance to a constant background of local odours.

The exception to this may occur under the following individual or combined

circumstances, when:

1. An odour is particularly strong and/or offensive

2. The odour occurs frequently and for extended periods

3. The odour becomes linked to possible health effects.

7.7.14 Potential odour effects during the construction phase have been assessed using a

risk-based approach in accordance with guidance produced by the IAQM (2018)

regarding the assessment of odour for planning. The guidance includes a

summary of predictive and observational/empirical assessment tools and

assessment criteria.



7.7.15 The assessment uses the Source-Pathway-Receptor (S-P-R) concept.

Specifically, the significance of effects has been determined in relation to the likely

level of odour exposure experienced by receptors, and their sensitivity. The nature

of the source, the distance to receptors and the frequency of wind conditions that

could transport odour to the receptors have been considered.

7.7.16 This assessment is not a prediction of what will actually occur during the

operational life of the site but the potential for occurrences. Furthermore, an

occurrence does not mean that any of the receptors will experience an effect or

that this will give rise to a complaint.

7.7.17 The greatest potential for adverse odour effects to occur is during periods of stable

atmospheric conditions with calm or low wind speeds, generally when wind speeds

are less than 3 m s−1. This reduces dilution and mixing of odours with ambient air

and results in higher odour concentrations at receptor locations. The percentage of

time that a receptor is at risk is based on the following calculation:

Total number of operating hours as a fraction of number of hours when the

odour source operates in a year × fraction of hours when a wind of less than

3 m s−1 blows towards the receptor from the odour source.

7.7.18 The probability that the wind is blowing from the Airport towards the receptor, with

a speed of less than 3 m s−1, is calculated. A 45° range of wind directions centred

on the identified receptor is used to ensure that the spatial extent of the Airport is

captured, and also takes into account the uncertainty of the measured wind

directions and the plume width from the source.

7.7.19 This calculation uses long-term (5 years, 2013 – 2017) averaged weather data

from the Heathrow Airport synoptic meteorological station. From this calculation,

and the distance between the source and the nearest identified receptor in each

community area, the pathway is calculated and rated as described in Table 7.13.

Table 7.13: Matrix to determine pathway effectiveness

Distance from source

to receptor (m)

Frequency of low winds

<2% 2–5% >5%

>1,000 Ineffective Ineffective Ineffective

350-1,000 Ineffective Moderately effective Moderately effective

<350 Ineffective Moderately effective Highly effective

7.7.20 In accordance with IAQM (2018) guidance, dwellings medical facilities and

education sites are all considered to be highly sensitive receptors.



7.7.21 Table 7.14 and Table 7.15 present a matrices extracted from the IAQM guidance

for odour assessment, which show the interaction between the source potential,

odour pathway and sensitivity of receptors to derive the magnitude of the risk of

odour exposure. This has been used to determine the significance of any odour

effects at sensitive receptors in each community area.

Table 7.14: Risk of odour exposure at the specific receptor location

Pathway Effectiveness Source Odour Potential

Small Medium Large

Highly effective Low Medium High

Moderately effective Negligible Low Medium

Ineffective Negligible Negligible Low

Table 7.15: Descriptors of odour impact magnitude

Risk of odour exposure Receptor Sensitivity

Low Medium High

High Slight Moderate Substantial

Medium Negligible Slight Moderate

Low Negligible Negligible Slight

Negligible Negligible Negligible Negligible

Construction vehicle emissions

7.7.22 The impact of emissions from the additional road traffic vehicles during Phase 1 (c.

2022) has been assessed using the same dispersion modelling methodology as

described for the operational assessment. This enables the cumulative impacts of

construction and operational traffic to be considered.

Operational assessment methodology

The role of dispersion modelling

7.7.23 Whilst it is possible to measure concentrations of pollutants of concern, and

monitoring stations are operating in the area around Heathrow, air quality cannot

be measured at every location, and measurements do not allow future

concentrations to be estimated. Dispersion modelling is required to fill in the gaps

between monitoring sites and is the only way to predict likely significant effects in

future years. The assessment of operational effects has been carried out using the



Cambridge Environmental Research Consultants (CERC) ADMS-Airport (airport

sources), ADMS-Roads (road traffic emissions) and ADMS-5 (stationary

combustion sources) dispersion models. Dispersion modelling has the following

benefits:

1. It can fill in the spatial gaps between monitors, allowing air quality to be

assessed at all locations of interest

2. It makes it possible to see which sources are responsible for pollution and for

how much (‘source apportionment’)

3. It provides a basis for forecasting future air quality. Even for the future

baseline, there will be changes in the number and types of aircraft using the

Airport, for example. In addition, where there are proposals for changes to

airport infrastructure, such as a North West Runway, modelling is necessary to

understand the likely effects of such developments.

7.7.24 The assessment will largely follow the recommendations of PSDH (Department for

Transport, 2006), which is considered to be best practice in the assessment of air

quality around airports.

Detailed dispersion modelling

7.7.25 The detailed dispersion modelling process has included three key stages, which

are described further in Appendix 7.1.

1. For each modelled scenario, an emissions inventory has been developed to

calculate how much pollution is emitted from the different sources, based on

recorded activity levels and forecast future activity (including ATMs). In

addition, estimates have been included of the ‘background’ contribution in the

assessment year (i.e. the contribution from all sources not modelled explicitly).

Road traffic volume and speeds have been taken from the Heathrow Highway

Assignment and Surface Access Model (HHASAM). Road traffic emission

factors have been taken from the Defra EFT (version 8.0.1). NOX emissions

have also been calculated using the Calculator Using Realistic Emissions for

Diesels (CURED) sensitivity test which accounts for potential under-estimation

of emissions in the EFT from diesel vehicles from 2020

2. Detailed dispersion modelling has been used to calculate how the emissions

are carried through the air, due to meteorological conditions such as wind

speed and direction, to determine the concentrations of pollution in the air

3. These modelled concentrations have then been compared with the local

monitoring data in the model verification process as a check on the accuracy of

the model.



7.7.26 EFT version 9.0 (Defra, 2019a) was published in May 2019 during the production

of this chapter. It has not therefore been possible to incorporate the updated

emission factors in this assessment. The new version of the EFT utilises bespoke

vehicle fleet information and projections for London provided by TfL, taking

account of Ultra-Low Emission Zone (ULEZ) commencing in 2019. Average

pollutant emission rates in London therefore reduce more rapidly in the new

version of the EFT, and the results presented here are therefore considered to be

conservative. The latest available EFT will be used in the assessment reported in

the ES.

7.7.27 Annual mean concentrations of NOX, NO2, PM10, PM2.5 and SO2 have been

predicted. Shorter-period concentrations, which feature in some EU limit values

and AQOs, have been derived from annual mean values, using relationships that

have been recommended in technical guidance for LPA LAQM Review and

Assessment (Defra, 2016).

7.7.28 Concentrations have been calculated on a fine spatial grid throughout the Core

AQO Assessment Area. Concentrations have also been predicted at specific

receptor points within the Core AQO Assessment Area. This enables a more

detailed examination of concentration changes at particular sensitive receptor

locations. This set of receptors includes current monitoring sites close to the

Airport and other off-airport locations with relevant public exposure.

Tiered assessment of potential effects outside of the Core AQO Assessment Area

7.7.29 In order to determine potentially significant effects outside of the Core AQO

Assessment Area, which are related to the scale of changes in road traffic

associated with the DCO Project, a tiered approach to assessment has been used.

This approach has been used to determine discrete road links where changes in

road traffic could potentially lead to increases in pollution that cannot be

considered negligible / imperceptible, and that therefore require further

assessment using detailed dispersion modelling, in addition to that carried out for

the Core AQO Assessment Area. This assessment uses data from the HHASAM

Fully Modelled Area (FMA), defined as the geographic area of HHASAM in which

all trip movements are represented. The process of assessment is detailed in

Graphic 7.1.

7.7.30 Dispersion modelling has been used to determine an indicative relationship

between emissions and concentrations. NOX emission rates for each year have

been determined using the CURED tool (Air Quality Consultants, 2018). This has

been carried out using Outer London emission factors, and a speed of 20kph for

both LDVs and HDVs separately. The ADMS-Roads dispersion model has been

run with a unitary NOX emission rate (0.001g/s) to determine the resultant annual

mean NOX concentration at a receptor 4m from a 1km link (representative of a



roadside receptor). A southwest to northeast orientation has been used as, due to

wind patterns, the effect on concentrations is greatest. This has been carried out

with and without the street canyon module. This has been combined with the

average emission rates per vehicle in each assessment year.

Graphic 7.1: Tiered assessment of potential effects outside of the Core AQO Assessment Area

Effect significance in relation to Air Quality Objectives

7.7.31 The significance of effects on NO2 and PM concentrations at receptors on the

urban road network has been assessed in accordance with guidance developed

by the IAQM and Environmental Protection UK (EPUK) (2017). The impact

descriptors also take account of the incremental change in air quality at relevant

receptors and the absolute concentration in relation to AQOs.



7.7.32 The descriptors are shown in Table 7.16. These criteria are based on the change

in concentration of a pollutant at an existing receptor location due to a new

development, as a percentage of the Air Quality Assessment Level (AQAL) (i.e.

the AQO). The table is intended to be used by rounding the change in percentage

pollutant concentration to whole numbers, which then makes it clearer which cell

the impact falls within. Changes of less than 0.5% have been described as

negligible independent of the percentage of the AQAL.

Table 7.16: Impact descriptors for individual receptors – urban road network

Long term average

concentration at

receptor

in assessment year

% Change in concentration relative to Air Quality Assessment Level

(AQAL)

< 1

(<0.2μg/m³)

1 (0.2-

0.6μg/m³)

2-5 (0.6 –

2.2μg/m³)

6 – 10 (2.2 –

4.2μg/m³)

>10

(>4.2μg/m³)

75 % or less of AQAL

(30.2μg/m³)

Negligible Negligible Negligible Slight Moderate

76-94 % of AQAL (30.2 –

37.8μg/m³)

Negligible Negligible Slight Moderate Moderate

95 – 102% of AQAL

(37.8 – 41.0μg/m³)

Negligible Slight Moderate Moderate Substantial

103 – 109 % of AQAL

(41.0 – 43.8μg/m³)

Negligible Moderate Moderate Substantial Substantial

110% or more of AQAL

(>43.8μg/m³)

Negligible Moderate Substantial Substantial Substantial

Notes: Concentrations are shown for annual mean NO2 AQO. When defining the concentration as a percentage of the

AQAL, the ‘without scheme’ concentration is used where there is a decrease in pollutant concentration, and the ‘with

scheme;’ concentration for an increase. The total concentration categories reflect the degree of potential harm by

reference to the AQAL value. At exposure less than 75% of this value, i.e. well below, the degree of harm is likely to be

small. As the exposure approaches and exceeds the AQAL, the degree of harm increases. This change naturally

becomes more important when the result is an exposure that is approximately equal to, or greater than the AQAL. It is

unwise to ascribe too much accuracy to incremental changes or background concentrations, and this is especially

important when total concentrations are close to the AQAL. For a given year in the future, it is impossible to define the

new total concentration without recognising the inherent uncertainty, which is why there is a category that has a range

around the AQAL, rather than being exactly equal to it.

Overall assessment of significance

7.7.33 In accordance with both IAN 174/13 and EPUK/IAQM guidance, the overall

significance of the effect has been determined using professional judgement. This

is based upon consideration of the number of receptors predicted to experience a

worsening or improvement in air quality and the predicted concentrations relative

to the AQOs. The assessment of significance has been made on the basis of

following key criteria in relation to human health:

1. The risk that environmental standards will be breached



2. The probability of the effect occurring

3. Whether there will be a large change in environmental conditions

4. The duration of the effect

5. The number of people affected

6. The potential for avoiding or reducing or compensating for the effect

7.7.34 One of the relevant factors in the judgement of the overall significance of effect

may relate to the potential for cumulative impacts and, in such circumstances,

several impacts that are described as ‘slight’ individually could, taken together, be

regarded as having a significant effect for the purposes of air quality management

in an area, especially where it is proving difficult to reduce concentrations of a

pollutant. Conversely, a ‘moderate’ or ‘substantial’ impact may not have a

significant effect if it is confined to a very small area and where it is not obviously

the cause of harm to human health.

7.7.35 The consideration of the overall significance of effects on NO2 concentrations has

also been informed by the guidance contained in IAN 174/13. The magnitude of

change criteria for annual average NO2 and PM10 concentrations are shown in

Table 7.17. The assessment takes account of the total pollutant concentrations.

The higher above the air quality thresholds the changes are predicted to occur, the

greater the importance of the impact. Where the difference in concentrations is

less than 1% of the air quality threshold (e.g. less than 0.4μg/m³ for annual

average NO2) then the change at these receptors is considered to be negligible

and they can be scoped out of the judgement on significance.

Table 7.17: Impact descriptors for individual receptors – Strategic Road Network

Magnitude of change in concentration (μg/m3) Value of change in annual average NO2 and PM10

Large (>4) Greater than full Measure of Uncertainty (MoU) value of 10 % of the air quality objective (4μg/m³).

Medium (>2 to 4) Greater than half of the MoU (2μg/m³), but less than the full MoU (4μg/m³) of 10% of the air quality objective.

Small (>0.4 to 2) More than 1% of objective (0.4μg/m³) and less than half

of the MoU i.e. 5% (2μg/m³). The full MoU is 10% of the

air quality objective (4μg/m³).

Negligible (≤0.4) Less than or equal to 1% of objective (0.4μg/m³).



Odour emissions and potential annoyance

7.7.36 Odour perception and its potential to cause annoyance is subjective and is

strongly dependent on the nature of the odour and the sensitivity or tolerance of

those exposed. As such, a semi-quantitative odour assessment has been

undertaken and reported in accordance with IAQM guidance (IAQM, 2018), as

referenced in relation to odour emissions associated with construction activities.

7.7.37 This considers the number and location of odour complaints received at Heathrow

under the current layout and likely changes following expansion. The odour source

(e.g. aircraft movements), the pathway for odour flux to receptor (e.g. distance and

direction in relation to prevailing wind direction) and receptor sensitivity have been

considered.

Assessment of the effect of the DCO Project on compliance with EU limit values

7.7.38 The impact of the DCO Project has been considered at key PCM assessment

locations. These PCM locations are shown in Figure 7.2, Volume 2.

7.7.39 Concentrations within the Core AQO Assessment Area have been predicted using

dispersion modelling under the future baseline scenario and the scenario with the

DCO Project, for each assessment year at each assessment location. This

enables the increment in NO2 concentration predicted as a result of the

development to be calculated. The increment in NO2 concentration resulting from

the DCO Project has been added to the concentration predicted using the PCM

model to determine a total NO2 concentration which can be used to consider

compliance. The total NO2 concentration predicted in this way has been compared

to the highest concentration predicted in the Greater London agglomeration zone

for that assessment year. This is consistent with the approach detailed in IAN

175/13 (Highways Agency, 2013b).

7.7.40 Outside the Core AQO Assessment Area the impact of the DCO Project on

pollutant concentrations towards Central London has been considered by

reference to predictions of airport-related traffic demand coming from those areas.

Cumulative effects

7.7.41 Cumulative air quality and odour effects resulting from the combination of effects

from the DCO Project and other developments will be assessed in accordance

with the approach set out in Section 5.8: Cumulative effects assessment.

7.8 Assumptions and limitations of this PEIR

7.8.1 The modelling and prediction of air quality inevitably requires a large number of

assumptions to be made, and it is important to highlight the associated uncertainty

and limitations and how their effect has been reduced. Assumptions are



unavoidable in air quality assessments and, wherever appropriate, a realistic

worst-case approach has been applied to ensure that predicted air quality impacts

with the DCO Project are not under-stated.

7.8.2 This section summarises the assumptions applied. More detail is available in

Appendix 7.1.

7.8.3 There are many components that contribute to the uncertainty of modelling

predictions. The emissions dispersion models used are dependent upon the input

data, which will have inherent uncertainties associated with them. There are then

additional uncertainties, as models are required to simplify complex atmospheric

conditions and interactions into a series of algorithms.

7.8.4 Assumptions relating to airside emissions include: necessary simplification of the

aircraft fleet into categories for emissions purposes; assumptions on future fleet

mix; assumptions on times that aircraft engines and APUs are operational and

their thrust settings when operational; assumptions on pollutant emission rates;

and assumptions relating to emissions from other sources such as heating plant

and airside vehicles.

7.8.5 HHASAM has been developed to assess the future operation of the road network.

Outputs from several of the other models within the modelling suite feed into

HHASAM, allowing for as robust an analysis as possible. Full details of the

modelling suite are available in the Preliminary Transport Information Report

(PTIR). In keeping with other strategic highway models, HHASAM estimates the

likely route choice of vehicles and predicts the resulting average levels of demand

on and operation of the highway network. Comparing forecast traffic flows

between scenarios gives an indication of the likely direction and scale of change in

demand and network operation. The air quality assessment has used outputs from

HHASAM v2.0. This is calibrated to a 2015 base year as this is the year for which

most of the demand and traffic count data that is required for the model

development was collected.

7.8.6 The development of HHASAM v2.0 has followed guidance set out in the DfT’s

WebTAG Unit M3.1, adopting and enhanced with best practice as far as

practicable. HHASAM v2.0 is considered to be suitable for refining Future Baseline

forecasts and developing initial 'With DCO Project' forecasts to provide traffic

information for the PTIR and PEIR. It is envisaged that HHASAM v2.0 will undergo

further refinement prior to the Application submission for the DCO Project.

7.8.7 As with the use of all strategic highway assignment model outputs in air quality

assessments, assumptions have been made in the use of HHASAM outputs for

this assessment. These include the use of AADT flows rather than more detailed

period breakdowns, and the use of relatively long sections of road to represent

actual driving conditions that may change over small distances. HHASAM outputs



do not provide splits of buses / coaches, splits of rigid / articulated HGVs, splits of

taxi/Private Hire Vehicle flows and motorcycle flows, as such HHASAM outputs

have been supplemented by the fleet splits assumed in the Defra EFT to enable

robust predictions of pollutant emissions.

7.8.8 There are additional limitations associated with the traffic data used for the 2022

assessment, due to the way in which flows were derived, by overlay of

construction traffic rather than construction traffic being included in HHASAM. The

full impacts of the CTMP and CWTP have not been accounted for in this

approach. The road traffic flows used in this assessment are therefore considered

to be worst-case for this assessment year. Construction traffic will be modelled

using the refined version of HHASAM for the ES and the CTMP and CWTP will be

accounted for.

7.8.9 Further assumptions are required to process dispersion model outputs. Industry

standard tools, such as the Defra background maps and NOx to NO2 calculator

have been used. The background maps provide concentrations at a limited (1 km)

resolution (which have then been interpolated), are likely to over-estimate rail

emissions on the Great Western Mainline, and also have limitations in terms of

what emission sources can be removed from them, although a worst-case

approach with some limited double-counting of emissions has been adopted. The

NOx to NO2 calculator uses primary NO2 (fNO2) values for road traffic emissions

that are considered likely to be unrealistic, although these are largely accounted

for through secondary adjustment of the modelled NO2 concentrations. Inputs to

these tools necessarily have to be simplified when considering impacts over large

area such as the Core AQO Assessment Area to avoid step changes in modelled

concentrations (e.g. the selection of a LPA area when using the NOx to NO2

calculator), which introduces some limitation in the consideration of changes in

parameters between different areas.

7.8.10 An important stage in the process is model verification, which involves comparing

the model output with measured concentrations to provide confidence in base year

predictions and predictions of future air quality. It is recognised that all air quality

monitors have inherent measurement uncertainties, however, the number of

monitoring stations in the area is considered to enable a robust model verification

process to be carried out.

7.8.11 Overall, it is considered that, given the approach taken to make the required

assumptions in this assessment, the conclusions drawn are robust. These

assumptions will be revisited as necessary in the assessment carried out for the

ES.



7.9 Overall baseline

Current baseline

Ambient air quality

7.9.1 Air quality in the Heathrow area has been routinely assessed for the last two

decades, through both ambient air quality monitoring and modelling studies.

Previous dispersion modelling (Ricardo-AEA, 2015) has shown that in the area

outside of the Airport boundary, the main sources of pollution that influence air

quality are non-airport-related. Emissions source apportionment showed that, in

decreasing order of influence, pollutant concentrations beyond the Airport

boundary are affected by:

1. The ambient background (pollutants transported from elsewhere, including

London and northern Europe)

2. Non-airport-related road traffic (trips in the modelled area not starting or ending

at the Airport)

3. Airport-related road traffic (trips starting at or ending at the Airport)

4. Emissions from on-airport activities, including aircraft on the ground and in the

LTO cycle

Local air quality management

7.9.2 As explained in Table 7.1, each LPA is required to assess air quality within the

administrative area and declare an AQMA where an AQO is expected to be

exceeded. The AQOs that apply in the LAQM process are detailed in Table 7.18.

Table 7.18: UK air quality objectives and pollutants – LAQM in England

Pollutant Concentration Measured as

Benzene 16.25 µg/m3 Running annual mean

5.00 µg/m3 Annual mean

1,3-Butadiene 2.25 µg/m3 Running annual mean

Carbon monoxide 10.0mg/m3 Running 8-hour mean

Lead 0.25µg/m3 Annual mean

Nitrogen dioxide 200µg/m3 not to be exceeded more

than 18 times a year

1-hour mean

40µg/m3 Annual mean

Particulate Matter (PM10) 50µg/m3, not to be exceeded more 24-hour mean



Pollutant Concentration Measured as


40µg/m3 Annual mean

Particulate Matter (PM2.5) 25µg/m3 Annual mean

Sulphur dioxide 350µg/m3, not to be exceeded more


1-hour mean

125µg/m3, not to be exceeded more

than 3 times a year

24-hour mean

266µg/m3, not to be exceeded more


15-minute mean

7.9.3 As part of the LAQM Review and Assessment process, several AQMAs have been

declared in the area. These AQMAs were declared because annual average

concentrations of NO2 were found to be above the annual mean AQO of 40 µg/m3

at certain locations, including those close to busy roads and motorways. However,

the NO2 annual mean AQO is not exceeded everywhere in each AQMA.

7.9.4 The London Borough of Hillingdon declared an AQMA in 2001, which was then

extended in 2003 to cover all parts of the borough south of the Chiltern-

Marylebone railway line. Heathrow sits within the southern part of this AQMA. The

councils of London Borough of Hounslow, Spelthorne Borough Council, Slough

Borough Council, South Bucks District Council and Runnymede District Council

have declared AQMAs in their boroughs. London Borough of Hounslow

amalgamated four existing AQMAs into one AQMA to encompass the whole

Borough and Spelthorne Borough Council declared the whole Borough as an

AQMA. Slough Borough Council has declared four AQMAs; including AQMA No.2

which encompasses the A4 London Road east of junction 5 of the M4 motorway

as far as Sutton Lane, in Brands Hill, approximately 3km to the west of Heathrow.

South Bucks District Council has an AQMA covering the whole parish of Iver.

Runnymede District Council currently has two AQMAs, including the M25 AQMA

where the M25 crosses over Vicarage Road / High Street Egham, approximately

4km to the southwest of Heathrow. These AQMAs are shown in Figure 7.3,

Volume 2.

7.9.5 Concentrations of the other significant air pollutants that can affect public health,

including PM10 and PM2.5, already meet the AQOs and are forecast to continue to

do so into the future.



Air quality monitoring

Automatic monitoring

7.9.6 The Heathrow Air Quality Working Group (a partnership between Heathrow,

London Borough of Hillingdon, London Borough of Hounslow, Slough Borough

Council, Spelthorne Borough Council, the GLA, TfL and the Environment Agency)

works collaboratively to monitor, share and publish data from 22 continuous air

quality monitoring stations within approximately 20 kilometres (km) of Heathrow.

The data collected can be found on the Heathrow Airwatch (2019) website.

7.9.7 One of these monitoring stations is located within the Airport boundary (called

LHR2), and several of these are located immediately within the vicinity of

Heathrow (Heathrow Oaks Road, Heathrow Green Gates, Sipson, Oxford Avenue,

Cranford and Hatton Cross). Details of the monitoring stations in the area

surrounding Heathrow and within the Core AQO Assessment Area, along with

measured annual mean concentrations of NO2, PM10 and PM2.5 from 2014 – 2017,

are provided in Table 7.19 to Table 7.21. Monitoring station locations are provided

in Figure 7.4, Volume 2.

7.9.8 These data confirm that PM10 concentrations do not exceed the annual AQO. The

highest PM10 annual mean concentration recorded in the 2014 – 2017 period was

34µg/m3 at Hillingdon Hayes in 2014. The 24-hour AQO (50µg/m3 not to be

exceeded more than 35 times/year) was exceeded once in 2014 at Hillingdon

Hayes (46 exceedances of the 24-hour AQO).

7.9.9 NO2 concentrations exceed the annual mean AQO at two roadside monitoring

sites (London Hillingdon and Hillingdon Hayes), but the concentration is below

40µg/m3 at other roadside sites, and background locations. The highest NO2

annual mean concentration recorded in the 2014 – 2017 period was 58µg/m3 in

2014 at London Hillingdon. The NO2 1-hour mean objective (200µg/m3 not to be

exceeded more than 18 times / year) was not exceeded in this period as the

highest number of exceedances was 12, in 2017 at Hillingdon Hayes and LHR2.

7.9.10 Over the four years, several sites have shown a downward trend in NO2

concentrations, with a strong downward trend at the Feltham roadside monitoring

site. There have been downward trends at the Oaks Road, London Hillingdon and

Colnbrook suburban/urban background monitoring sites. Concentrations have

remained relatively constant at the other sites.

7.9.11 There have been downward trends in PM10 concentration at all stations with the

exception of Hillingdon Harmondsworth and Hillingdon Hayes, where

concentrations have remained relatively constant. There have been downward

trends in PM2.5 concentration at the majority of stations. The highest annual mean

recorded was 14µg/m3 in 2014 at London Harlington.



Nitrogen dioxide diffusion tubes

7.9.12 NO2 diffusion tube monitoring data is available at a much larger number of sites

than the continuous air quality monitoring stations. Data have been taken from the

2017 LAQM Annual Status Reports (ASRs) produced by each LPA. The data is

summarised in Figure 7.5, Volume 2.

7.9.13 The pattern seen at automatic monitoring stations is repeated. NO2 concentrations

exceed the annual mean AQO at some roadside monitoring sites, but the

concentration is below 40µg/m3 at other roadside sites, and background locations.

Other pollutants

7.9.14 Concentrations of CO, SO2 and benzene were previously monitored in the London

Borough of Hillingdon. Successive LAQM reports (London Borough of Hillingdon,

2007; London Borough of Hillingdon, 2008, London Borough of Hillingdon, 2009)

confirmed that all of the relevant AQOs for these pollutants had been achieved

and therefore there was no risk of the AQOs being exceeded.

7.9.15 In 2007, the maximum daily running 8-hour CO mean at all monitoring stations

was well below 1µg/m3 (0.3 to 0.5µg/m3), compared to the AQO of 10µg/m3. The

1-hour mean, 24-hour mean and 15-minute mean SO2 AQOs were all achieved

and the annual mean benzene concentrations at all diffusion tube monitoring sites

was around 2µg/m3 (1.9 to 2.2µg/m3), compared to the AQO of 5µg/m3.

7.9.16 As concentrations of these pollutants were so low in the area, monitoring was

discontinued and no recent data is available. Monitoring of CO was discontinued

at the AURN sites in London Borough of Hillingdon in 2007 and 2008. Benzene

monitoring was discontinued in 2010 (London Borough of Hillingdon, 2011).

Monitoring of SO2 concentrations at the London Hillingdon AURN monitoring

station was discontinued in 2007 (Defra, 2018h).



Table 7.19: Automatic air quality monitoring station details and measured annual mean NO2 concentrations (µg/m3)

Site name Type OS Coordinates Height (m) Distance to

kerb (m)

Road Annual mean NO2 concentrations (µg/m3)

X (m) Y (m) 2014 2015 2016 2017

London

Hillingdon

Suburban 506943 178608 3 35 M4 58 (0) 52 (0) 52 (2) 53 (0)

LHR2 Airport 508392 176743 3 12.5 Northern

Perimeter Road

46 (0) 44 (2) 48 (8) 48 (12)

Heathrow Oaks

Road

Urban

Background

505737 174496 3 4 Oaks Road

(minor road)

33 (0) 27 (0) 31 (0) 26 (0)

Heathrow

Green Gates

Airport 505184 176922 3 13 Bath Road 35 (0) 32 (0) 34 (0) 32 (0)

Hillingdon

Oxford Avenue

Roadside 509554 176977 1.7 21 Bath Road (A4) No data

(0)

35 (2) 39 (0) 35 (1)

HS2 - Cranford Background 510375 177199 2.5 73 High Street

(minor road)

31 (0) 30 (0) 31 (2) 30 (10)

London

Harlington

Airport/

Roadside

508295 177799 3 6.9 Sipson Lane

(relatively minor)

36 (0) 32 (0) 34 (0) 32 (0)

Hillingdon

Sipson

Urban

Background

507328 177289 1.7 87 Sipson Way

(Minor)

37 (0) 34 (3) 36 (0) 34 (0)

HS7 - Hatton

Cross

Urban

Background

509336 174999 2.5 87 Great South West

Road (A30)

31 (0) 30 (0) 32 (0) 33 (0)

Hillingdon

Harmondsworth

Roadside 505563 177660 1.7 1 Moor Lane (very

minor)

29 (0) 28 (1) 27 (0) 27 (0)

Hillingdon

Hayes

Roadside 510305 178887 1.7 1.1 North Hyde Road 53 (2) 46 (2) 47 (1) 47 (12)



Site name Type OS Coordinates Height (m) Distance to

kerb (m)

Road Annual mean NO2 concentrations (µg/m3)

X (m) Y (m) 2014 2015 2016 2017

Slough

Colnbrook

Urban

Background

503536 176825 2.9 155 Bath Road 31 (0) 29 (0) 29 (0) 25 (0)

Spelthorne

Sunbury Cross

Urban

Background

510063 170212 3.0 17.0 The Haven No data No data No data 33 (0)

Slough Brand

Hill London

Road

Roadside 501644 177752 9.0 London Road No data No data No data 38 (0)

Hounslow

Feltham

Roadside 510683 173259 2.0 4.0 Hanworth Road 43 (0) 40 (0) 38 (0) 34 (0)

Notes:

Exceedances of the NO2 annual mean AQO of 40µg/m3 are shown in bold.

Exceedances of the NO2 1-hour mean concentration of 200µg/m3 (not to be exceeded more than 18 times/year) are shown in brackets.



Table 7.20: Automatic air quality monitoring station details and measured annual mean PM10 concentrations (µg/m3)

Site name Type OS Coordinates Height

(m)

Distance to kerb (m)

Road

Annual mean PM10 concentrations (µg/m3)

X (m) Y (m) 2014 2015 2016 2017

LHR2 Airport 508392 176743 3 12.5 Northern Perimeter Road

18 (6) 13 (3) 15 (3) 15 (7)

Heathrow Oaks Road

Urban Background

505737 174496 3 4 Oaks Road (minor road)

18 (6) 14 (5) 15 (2) 14 (4)

Heathrow Green Gates

Airport 505184 176922 3 13 Bath Road 17 (5) 14 (3) 14 (3) 14 (3)

Hillingdon Oxford Avenue

Roadside 509554 176977 1.7 21 Bath Road (A4) 21 (4) 19 (3) 21 (11) 19 (4)

HS2 - Cranford Background 510375 177199 2.5 73 High Street (minor road)

19 (2) 17 (4) 18 (8) 18 (5)

London Harlington Airport/ Roadside

508295 177799 3 6.9 Sipson Lane (relatively minor)

20 (5) 16 (3) 15 (5) 15 (3)

HS7 - Hatton Cross

Urban Background

509336 174999 2.5 87 Great South West Road (A30)

20 (4) 18 (4) 19 (6) 18 (3)

Hillingdon Harmondsworth

Roadside 505563 177660 1.7 1 Moor Lane (very minor)

21 (6) 22 (4) 23 (3) 23 (6)

Hillingdon Hayes Roadside 510305 178887 1.7 1.1 North Hyde Road 34 (45) 28 (14) 28 (32) 27 (26)

Slough Colnbrook Urban Background

503536 176825 2.9 155 Bath Road 19 (0) 17 (3) 18 (5) 17 (4)

Hounslow Feltham Roadside 510683 173259 2.0 4.0 Hanworth Road 21 (3) 19 (4) 19 (7) 19 (4)

Spelthorne Sunbury Cross

Urban Background

510063 170212 3.0 17.0 The Haven No data No data No data 13 (0)

Slough Brand Hill London Road

Roadside 501644 177752 9.0 London Road No data No data No data 24 (5)

Notes:

Exceedances of the PM10 24-hour mean of 50µg/m3 (not to be exceeded more than 35 times/year) are shown in brackets.



Table 7.21: Automatic air quality monitoring station details and measured annual mean PM2.5 concentrations (µg/m3)

Site name Type OS Coordinates Height

(m)

Distance to kerb (m)

Road

Annual mean PM2.5 concentrations (µg/m3)

X (m) Y (m) 2014 2015 2016 2017

LHR2 Airport 508392 176743 3 12.5 Northern Perimeter Road

9 9 9 9

Heathrow Oaks Road

Urban Background

505737 174496 3 4 Oaks Road (minor road)

10 9 9 9

Heathrow Green Gates

Airport 505184 176922 3 13 Bath Road 10 9 9 8

London Harlington Airport/ Roadside

508295 177799 3 6.9 Sipson Lane (relatively minor)

14 10 10 9

Spelthorne Sunbury Cross

Urban Background

510063 170212 3.0 17.0 The Haven No data No data No data 8



Dust deposition

7.9.17 Ambient dust deposition rates are not monitored extensively in the UK. Monitoring

that is undertaken is usually connected with specific activities such as mining and

mineral extraction operations or specific large-scale construction programmes.

Dust monitoring may also be undertaken to investigate specific complaints

received by LPAs, who are then required to investigate dust nuisance under the

Environmental Protection Act 1990.

7.9.18 Dust deposition rates are not currently monitored in the Heathrow area. Current

dust levels in the areas potentially affected by the DCO Project are expected to be

well below annoyance levels due to the nature of land uses in the area and lack of

likely emission sources. Monitoring of baseline PM and dust deposition levels will

be undertaken in advance of commencement of the construction programme.

Odour

7.9.19 Similar to dust deposition rates, odour levels are not routinely monitored in the UK.

Baseline odour surveys will be undertaken in advance of commencement of the

construction programme and the assessment will be informed by data on any

complaints received in relation to existing airport activities.

7.9.20 Heathrow operates a system to receive and record complaints from members of

the public. The majority of complaints received relate to aircraft noise, but

complaints related to other issues are also logged in categories including ‘Aircraft

Emissions’, ‘Health / pollution Levels’ and ‘Odour’.

7.9.21 Complaints from July 2014 to November 2018 have been considered. In the

52 months for which complaints data were available, 47 complaints from 42

different complainants / locations were received where the complainant clearly

believed that they could smell aviation fuel odours. This averages fewer than one

complaint per month. Figure 7.6, Volume 2 shows their locations. As seen on this

figure, some of the odour complaints received were located as far as 40 km away

from the Airport. Such complaints are most likely to be due to emission sources

not associated with the Airport, and could also potentially relate to activity at other

airports.

Dispersion modelling

7.9.22 Baseline pollutant concentrations for 2015, 2016 and 2017 have been calculated

using dispersion modelling. Pollutant concentrations have been predicted at the

locations of automatic air quality monitoring stations in order to evaluate modelling

performance in the model verification process. Dispersion modelling results have

been adjusted accordingly to ensure that baseline concentrations are

representative of the likely concentrations at receptors and that the model can be



used to predict future concentrations. Details of the model inputs, assumptions

and the verification are provided in Appendix 7.1.

Future baseline

7.9.23 Future baseline concentrations have been predicted using dispersion modelling.

Details of the model inputs, assumptions and the verification are provided in

Appendix 7.1, together with the method used to derive future year background

concentrations. Where assumptions have been made, a reasonable worst-case

approach has been adopted.

7.9.24 The likely evolution of the baseline conditions if the DCO Project did not come

forward has been considered in this assessment. The traffic modelling on which

the dispersion modelling to predict future pollutant concentrations is based takes

account of employment and housing projections, future infrastructure projects and

development in Development Plans and the planning process. Further detail on

the traffic modelling is available in the PTIR.

7.9.25 Furthermore, changes in baseline conditions as a result of other development

being pursued at Heathrow Airport have been taken into consideration, including

the Kilobox Apron Development and Runway Access Taxiway projects, described

in Table 5.1 of Chapter 5, which would be completed prior to the commencement

of construction of the DCO Project.

7.9.26 Additional Heathrow Airport supporting development may also come forward in the

future (with their construction and operation phases overlapping with the

construction and/or operation phases of the DCO Project). Such development is

considered within Section 7.11.

7.9.27 There will also be other changes in baseline conditions in the wider area as a

result of land use changes through development un-related to Heathrow Airport.

Such ‘other development’ could result in new receptors or result in other

cumulative effects with the DCO Project. Where these developments are built out

before the construction of the DCO Project commences, or where the construction

and operation phases of these developments overlap with the construction and/or

operation phases of the DCO Project, they are assessed in Section 7.11.

7.9.28 Air quality is generally expected to improve with time, due, for example, to more

stringent emissions standards for motor vehicles. The pollutant concentrations

presented for the 2035 future baseline (and 2035 with the DCO Project) are higher

than would be expected in reality as 2030 background maps and emission factors

have been used, as this is the latest date for which such projections are available.

Background pollutant concentrations and emission rates are expected to continue

to decline after 2030, in particular as a result of the wider uptake of ULEVs.



7.10 Assessment of air quality and odour effects

Introduction

7.10.1 The preliminary assessment of the effects of the DCO Project on air quality and

odour is described in this section.

Construction

Dust and PM

7.10.2 A detailed risk assessment of the potential for dust impacts has been carried out in

accordance with IAQM guidance (IAQM, 2014). Details of the construction

programme, construction activities and areas of construction activity are provided

in Section 6.4 of Chapter 6: DCO Project description. The risk assessment is

used to determine environmental measures designed to reduce emissions and

effects and, as such, does not reflect that good practice environmental measures

that will be employed during the construction process as detailed in the draft

CoCP and summarised in Section 7.5. The significance of effects is determined

giving full consideration to the measures which are to be adopted.

7.10.3 Table 7.22 shows that the dust emission magnitude is predicted to be large for all

activity types, except for demolition, which will not be carried out from 2026 and

thereafter, and major earthworks, which will not be required after the North West

Runway is operational. Phase 3 is not considered here as any remaining

construction activities, such as development of Terminal 2, will take place over

350m from sensitive receptors.

Table 7.22: Dust emission magnitude

Period Demolition Earthworks Construction Trackout

Phase 1 Large (N/A after 2025) Large Large Large

Phase 2 N/A N/A Large Large

7.10.4 Sensitivities of the areas to dust soiling and human health effects for Phase 1 and

Phase 2 are included in Table 7.23.

7.10.5 Hayes, Heston, Hounslow (Central and South), Hounslow (West and Heath),

Longford, Cranford and Cranford Cross are not considered to be sensitive to any

activities in all Phases as there are no receptors within 350m of the activities.



7.10.6 No areas are considered to be sensitive to trackout impacts in all Phases, as there

are no receptors within 50m of construction routes on public highways within 500m

of the anticipated site entrances.

Table 7.23: Sensitivity of areas to dust soiling effects and human health effects

Community Activities Dust soiling effects Human health effects

Phase 1 Phase 2 Phase 1 Phase 2

Harmondsworth Demolition Medium Negligible Low Negligible

Earthworks Low Negligible Low Negligible

Construction Medium Low Low Negligible

Trackout Negligible Negligible Negligible Negligible

West Drayton Demolition Negligible Negligible Negligible Negligible


Construction Low Negligible Low Negligible


Sipson Demolition Low Negligible Low Negligible

Earthworks High Negligible Low Negligible

Construction High Negligible Low Negligible


Harlington Demolition Negligible Negligible Negligible Negligible


Construction Medium Negligible Low Negligible


Feltham North Demolition Negligible Negligible Negligible Negligible

Earthworks Negligible Negligible Negligible Negligible

Construction Negligible Negligible Low Negligible


Bedfont Demolition Negligible Negligible Negligible Negligible




Stanwell Demolition Negligible Negligible Negligible Negligible

Earthworks Medium Negligible Low Negligible

Construction High Low Low Low


Stanwell Moor Demolition Low Negligible Low Negligible






Construction Low Low Low Negligible


Poyle Demolition Medium Negligible Low Negligible




Colnbrook Demolition Negligible Negligible Low Negligible




Brands Hill Demolition Negligible Negligible Negligible Negligible




Iver and Richings

Park

Demolition Negligible Negligible Low Negligible




7.10.7 The sensitivities to dust soiling effects and human health effects are combined

with the dust emission magnitudes, to determine the risk of impacts, presented in

Table 7.24. Risks for Hayes, Heston, Hounslow (Central and South), Hounslow

(West and Heath), Longford, Cranford and Cranford Cross are negligible for both

phases and for all activities as the sensitivities of these areas are negligible due to

the distance from construction activities. Trackout risks are negligible for all areas

and for both phases as there are no receptors within 500m of anticipated site

entrances.

Table 7.24: Risks of dust soiling impacts and human health impacts



Harmondsworth Demolition High Negligible Medium Negligible






Construction Medium Low Low Negligible


West Drayton Demolition Negligible Negligible Negligible Negligible




Sipson Demolition Medium Negligible Medium Negligible

Earthworks High Negligible Low Negligible



Harlington Demolition Negligible Negligible Negligible Negligible




Feltham North Demolition Negligible Negligible Negligible Negligible




Bedfont Demolition Negligible Negligible Negligible Negligible




Stanwell Demolition Negligible Negligible Negligible Negligible


Construction High Low Low Low


Stanwell Moor Demolition Medium Negligible Medium Negligible


Construction Low Low Low Negligible


Poyle Demolition High Negligible Medium Negligible








Colnbrook Demolition Negligible Negligible Medium Negligible




Brands Hill Demolition Negligible Negligible Negligible Negligible




Iver and

Richings Park

Demolition Negligible Negligible Medium Negligible




7.10.8 As discussed in the IAQM guidance (IAQM, 2014), for almost all construction

activity, the aim should be to prevent significant effects on receptors through the

use of effective environmental measures. Experience shows that this is normally

possible. It is therefore assumed that the good practice environmental measures

highlighted in Section 7.5 and contained in the draft CoCP will ensure that a

potential significant adverse effect will not occur, so the residual effect will

normally be not significant.

7.10.9 It is acknowledged that drawing this conclusion assumes that the environmental

measures are successfully implemented. The draft CoCP details the protocols

that will be established to ensure the effective implementation of measures and

the monitoring of these measures and any emissions.

7.10.10 Furthermore, it is recognised that, even with rigorous implementation of these

environmental measures to control dust emissions, it is not possible to guarantee

that they will be effective all of the time. For example, the local community may

experience occasional, short-term dust annoyance under adverse weather

conditions, or when a specific, short-term activity is carried out. The likely scale of

such short-term effects is not considered to be sufficient to change the conclusion

that with the good practice environmental measures implemented, effects will be

not significant. Should incidences of high dust emissions occur, these may be

identified through the monitoring programme and activities will be amended where

practicable to reduce emissions. A procedure for raising complaints, and



subsequent investigation will also be established. Further detail is available in the

draft CoCP.

Odour

7.10.11 Table 7.25 summarises the results from the risk-based assessment of odour

relating to construction activities. This assumes that there are odorous emissions

during earthworks. Contaminated materials may be excavated during the DCO

Project, the excavated materials could contain volatile compounds that may give

rise to odour impacts in early phases of the construction period. All community

areas contain high sensitivity receptors.

7.10.12 As with construction dust, for almost all construction activity, the aim should be to

prevent significant effects on receptors due to odour through the use of effective

environmental measures. Experience shows that this is normally possible. For this

reason, although the nature of potentially odorous emissions is not fully

understood at this stage and the hedonic tone could potentially be offensive, the

source is considered to have a medium odour potential. This is in accordance with

IAQM (2018) guidance in which one consideration for classifying sources as

having a medium odour potential refers there being ‘some mitigation measures in

place, but significant residual odour remains’.

7.10.13 It is important to note that the risk-based assessment is not a prediction of what

will actually occur during the construction of the DCO Project but the potential for

occurrences, based on the meteorological data available from Heathrow Airport.

Furthermore, emission of an odour does not mean that any of the receptors will

experience an effect on amenity or be caused to raise a complaint.

7.10.14 Areas towards the south and south-east of the Airport are less likely to have odour

emissions dispersed towards them. This is because prevailing winds at Heathrow

are predominantly from the west, south-west and, to a lesser extent, the

north-east, and because the main earthworks activities are to the north-west of the

site. The wind rose is shown in Graphic 7.2.



Graphic 7.2: Wind rose for Heathrow Airport meteorological data 2013 – 2017



Table 7.25: Construction odour risk-based assessment

Community Area Source Odour Potential

Percentage winds at low speeds (< 3m/s)

Distance of extraction of historic landfill to nearest receptor in community area (m)

Pathway Effectiveness

Risk of Odour Exposure

Receptor Sensitivity

Odour impact

Harmondsworth Medium 5.1% 184 High Medium High Moderate Adverse

West Drayton Medium 5.1% 760 Moderate Low High Slight Adverse

Sipson Medium 5.1% 0 High Medium High Moderate Adverse

Harlington Medium 4.9% 130 Moderate Low High Slight Adverse

Hayes Medium 4.9% 1674 Ineffective Negligible High Negligible

Cranford Cross Medium 4.9% 1930 Ineffective Negligible High Negligible

Cranford Medium 4.1% 3055 Ineffective Negligible High Negligible

Heston Medium 4.1% 3890 Ineffective Negligible High Negligible

Hounslow (Central and South)

Medium 1.8% 6510 Ineffective Negligible High Negligible

Hounslow (West and Heath)


Feltham North Medium 2.1% 3654 Ineffective Negligible High Negligible

Bedfont Medium 2.1% 3372 Ineffective Negligible High Negligible

Stanwell Medium 2.6% 1974 Ineffective Negligible High Negligible

Stanwell Moor Medium 2.6% 882 Moderate Low High Slight Adverse

Poyle Medium 4.1% 325 Moderate Low High Slight Adverse

Colnbrook Medium 5.7% 168 High Medium High Moderate Adverse

Brands Hill Medium 5.7% 744 Moderate Low High Slight Adverse

Iver and Richings Park

Medium 5.1% 752 Moderate Low High Slight Adverse



7.10.15 It is assumed that the good practice environmental measures highlighted in

Section 7.5 and contained in the draft CoCP will ensure that significant adverse

effects resulting from odour emissions associated with earthworks will not occur,

so the residual effect will normally be not significant.

7.10.16 It is possible that local communities may experience occasional, short-term odour

annoyance under specific weather conditions, or when a specific, short-term

activity is carried out. The likely scale of such short-term effects is not considered

to be sufficient to change the conclusion that with the good practice environmental

measures implemented, effects will be not significant. Should incidences of high

odour emissions occur, these may be identified through the monitoring programme

and activities will be amended where practicable to reduce emissions, including

application of further mitigation measures where appropriate. A procedure for

raising complaints, and subsequent investigation will also be established. Further

detail is available in the draft CoCP.

Pollutant concentrations during construction and operation

Overview

7.10.17 Concentrations of NO2, PM10, PM2.5 and SO2 have been modelled both without the

DCO Project and with the DCO Project in 2022, 2027, 2030 and 2035. Contours of

predicted NO2 concentration with the DCO Project in 2022, 2027, 2030 and 2035

are shown in Figure 7.7 to Figure 7.10, Volume 2.

7.10.18 The results for each community area are discussed individually to highlight the

likely changes in local air quality within each of them. The magnitude of impacts in

each community area are described using the EPUK/IAQM (2017) matrix in Table

7.16 which takes account of predicted concentrations, and the magnitude of

change. NO2 concentrations produced using the CURED sensitivity test are shown

in Appendix 7.1.

7.10.19 The overall conclusion on significance in relation to NO2 is then drawn on the

basis of predicted concentrations and changes in concentrations as a result of the

DCO Project at receptors across the Core AQO Assessment Area.

7.10.20 It should be noted that the road traffic data used to assess impacts in 2022 is

preliminary. It does not take full account of the proposed measures to manage

construction traffic. The CTMP and CWTP discussed in Section 7.5 will be

developed further in advance of the DCO application. The magnitude of impacts

presented here is therefore likely to be greater than when these mitigation

measures are taken into account. Results of the assessment using refined

construction phase modelling will be presented in the ES.



7.10.21 It is recognised that due to the natural upgrade of the national road vehicle fleet to

cleaner models over time, average emissions within each vehicle category, and -

also background pollutant concentrations, will decrease (Defra, 2017a). For this

reason, despite emissions associated with the North West Runway and increased

activity associated with the DCO Project (including airfield and LTO activities), air

quality is predicted to improve in future years at locations of relevant exposure.

Pollutant concentrations are predicted to be lower in 2027 than in the current

baseline years and even lower in 2035 and 2050 despite increases in airport

activity associated with the DCO Project.

7.10.22 It is important to note that the pollutant concentrations presented for 2035 are

higher than would be expected in reality as 2030 background maps and emission

factors have been used, as this is the latest date for which such projections are

available from Defra.

7.10.23 In addition, emissions per aircraft will decrease further. Through its Committee on

Aviation Environmental Protection (CAEP), the International Civil Aviation

Organization (ICAO) sets new emission standards for aircraft engines, including

for NOX. Engine models which were certified on or after 1 January 2014 must meet

CAEP8, the latest standard for NOX. The number of aircraft movements at

Heathrow made by CAEP8 aircraft increased to 28.6% at the end of 2018 and the

percentage continues to rise (Heathrow, 2019).

Short-term AQOs

7.10.24 Annual mean NO2 concentrations with the DCO Project are predicted to be below

60μg/m3 at all of the receptor locations in all modelled years and it is, therefore,

unlikely that the 1-hour mean NO2 AQO (200 µg/m3 not to be exceeded more than

18 times a year) will be exceeded. Results are not discussed further in relation to

this AQO.

7.10.25 Annual mean PM10 concentrations with the DCO Project are predicted to be below

32μg/m3 and it is, therefore, unlikely that the 24-hour mean PM10 AQO (50 µg/m3

not to be exceeded more than 35 times a year) will be exceeded at any of the

receptors. Results are not discussed further in relation to this AQO. There are no

short-term AQOs for PM2.5.

7.10.26 SO2 emissions from aircraft have been modelled, in order to allow assessment

against the SO2 objectives, all of which are short-term AQOs. These are the 15-

minute mean (266µg/m3 not to be exceeded more than 35 times a year), 1-hour

mean (350µg/m3 not to be exceeded more than 24 times a year) and 24-hour

mean (125µg/m3 not to be exceeded more than 3 times a year) AQOs. A common

way of assessing the risk of an exceedance of a short-term objective is to add the

concentration for the relevant percentile to two times the annual mean

concentration, and to compare the total to the AQO level (Environment Agency,



2016). There is no background monitor measuring SO2 close to Heathrow Airport,

with the nearest AURN site being in North Kensington. The annual mean SO2

concentration measured here in 2018 was 1.4µg/m3. Taking this value as a

representative background concentration, in order for any objective to be

exceeded the contribution of aircraft emissions would need to exceed the following

levels at locations of relevant exposure:

1. the 99.9th percentile of 15-minute mean SO2 concentrations would need to

exceed 263µg/m3;

2. the 99.73th percentile of 1-hour mean SO2 concentrations would need to

exceed 347µg/m3; and

3. the 99.18th percentile of 24-hour mean SO2 concentrations would need to

exceed 122µg/m3.

7.10.27 Model results at receptors outside of the DCO Project boundary have been

interrogated to determine the maximum contribution of aircraft emissions to short-

term SO2 concentrations. The 2035 scenario with the DCO Project has been used

as it is the modelled scenario with the highest number of aircraft movements, and

thus the highest SO2 emissions.

7.10.28 The maximum contribution to the 99.9th percentile of 15-minute mean SO2

concentrations outside of the DCO Project boundary is 92.4µg/m3. The maximum

contribution to the 99.73th percentile of 1-hour mean SO2 concentrations outside of

the DCO Project boundary is 65.6µg/m3. The maximum contribution to the 99.18th

percentile of 24-hour mean SO2 concentrations outside of the DCO Project

boundary is 23.3µg/m3. The process contribution of the aircraft emissions will not

exceed the given levels outside of the Airport boundary, with all of the process

contributions being less than half of the calculated thresholds. As such, there is

considered to be no risk of exceedance of the SO2 objectives as a result of the

DCO Project.

Community area results

Harmondsworth

7.10.29 Table 7.26 shows dispersion modelling results at 35 selected representative

receptor locations, including those which are likely to be worst-case in terms of

likely air quality impacts and total concentrations, within Harmondsworth. NO2

concentrations with the DCO Project and impacts are shown in Figure 7.11 and

Figure 7.12 (CURED sensitivity test), Volume 2.



Table 7.26: Dispersion modelling results for Harmondsworth

Year Maximum Concentration (µg/m3) Magnitude (µg/m3) Impact Descriptors at Selected Representative Receptors

Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 44.3 - - - - - - - - - - -

2022 - 34.1 35.2 0.0 1.2 0 0 0 28 7 0 0

2027 - 25.8 25.8 -2.4 5.5 0 0 1 25 5 4 0

2030 - 22.9 22.6 -0.9 6.0 0 0 0 24 6 5 0

2035 - 22.9 23.1 -2.3 6.6 0 0 1 21 7 6 0

PM10

2017 15.3 - - - - - - - - - - -

2022 - 14.8 14.9 0.0 0.2 0 0 0 35 0 0 0

2027 - 14.7 14.5 -0.2 0.6 0 0 0 35 0 0 0

2030 - 14.6 15.3 0.0 1.5 0 0 0 35 0 0 0

2035 - 14.6 15.6 -0.2 1.8 0 0 0 34 1 0 0

PM2.5

2017 10.0 - - - - - - - - - - -

2022 - 9.5 9.5 0.0 0.1 0 0 0 35 0 0 0

2027 - 9.3 9.3 -0.1 0.4 0 0 0 35 0 0 0

2030 - 9.2 9.7 0.1 1.0 0 0 0 35 0 0 0

2035 - 9.2 9.9 -0.1 1.1 0 0 0 35 0 0 0

Notes: Impacts described as beneficial or adverse and substantial, moderate, slight or negligible.

The maximum pollutant concentrations show the maximum at a receptor in a community area for a particular scenario. The maximum concentration

does not necessarily occur at the same receptor in the Future Baseline and With DCO Project scenario in each year.



7.10.30 In 2022, the maximum predicted increases in annual mean NO2 concentrations is

1.2μg/m3 (3% of the 40μg/m3 AQO) at a receptor close to the A4 Bath Road. The

maximum total concentration within Harmondsworth with the DCO Project is

35.2μg/m3, which is below the AQO. Of the 35 receptors modelled in

Harmondsworth, 28 are predicted to experience negligible impacts, with seven

predicted to experience slight adverse impacts. These conclusions remain

unchanged with the CURED sensitivity test.

7.10.31 In 2027, the maximum predicted increase in annual mean NO2 concentration is

5.5μg/m3 (14% of the 40μg/m3 AQO) at a receptor on Hatch Lane closest to the

North West Runway. The maximum total concentration within Harmondsworth with

the DCO Project is 25.8μg/m3, which is below the AQO. The maximum decrease

in annual mean concentration is 2.4μg/m3 at a receptor on Holloway Lane, where

traffic flows will be reduced due to the new A3044 configuration. Of the 35

receptors modelled in Harmondsworth, 25 are predicted to experience negligible

impacts, with one slight beneficial, five slight adverse and four moderate adverse

impacts. One of the moderate adverse impacts is reduced to slight adverse under

the CURED sensitivity test and one of the negligible impacts becomes slight

beneficial as the impact of reduced traffic flows is enhanced in the sensitivity test,

but the impact of increased ATMs remains.


6μg/m3 (15% of the 40μg/m3 AQO) at a receptor on Hatch Lane closest to the



in annual mean concentration is 0.9μg/m3 at a receptor on Holloway Lane. Of the

35 receptors modelled in Harmondsworth, 24 are predicted to experience

negligible impacts, with six slight adverse and five moderate adverse impacts. One

of the moderate adverse impacts is reduced to slight adverse under the CURED

sensitivity test and there are two receptors with slight beneficial impacts.

7.10.33 In 2035, the maximum predicted increase in annual mean NO2 concentrations is

6.6μg/m3 (17% of the 40μg/m3 AQO) at a receptor on Hatch Lane closest to the



in annual mean concentration is 2.3μg/m3 at a receptor on Holloway Lane. Of the

35 receptors modelled in Harmondsworth, 21 are predicted to experience

negligible impacts, with one slight beneficial, seven slight adverse and six

moderate adverse impacts. One of the moderate adverse impacts is reduced to

slight adverse, and eight of the negligible changes become slight beneficial under

the CURED sensitivity test. Under this test a moderate beneficial impact is

predicted at one receptor.



7.10.34 The maximum predicted annual mean PM concentrations occur at receptors close

to the A4 Bath Road. Annual mean PM10 and PM2.5 concentrations are predicted to

be well below the annual mean AQOs at all receptors in Harmondsworth in all

modelled years both without and with the DCO Project.

7.10.35 The maximum predicted increases in annual mean PM concentrations range from

around 0.2μg/m3 and 0.1μg/m3 for PM10 and PM2.5 respectively in 2022 at

receptors close to the A4 Bath Road, to 1.8μg/m3 and 1.1μg/m3 respectively in

2035 at receptors close to the A3044 Hatch Lane. All 35 receptors modelled in

Harmondsworth are predicted to experience negligible impacts from 2022 to 2030.

In 2035 one receptor close to the A3044 Hatch Lane is predicted to experience a

slight adverse impact, and all other receptors are predicted to experience

negligible impacts.

West Drayton



likely air quality impacts and total concentrations, within West Drayton. NO2





Table 7.27: Dispersion modelling results for West Drayton


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 56.6 - - - - - - - - - - -

2022 - 43.6 44.0 0.0 1.6 0 0 0 22 2 2 0

2027 - 32.3 33.7 0.3 2.1 0 0 0 23 3 0 0

2030 - 28.4 29.4 0.4 1.7 0 0 0 26 0 0 0

2035 - 28.7 29.8 0.4 2.3 0 0 0 23 3 0 0

PM10

2017 17.0 - - - - - - - - - - -

2022 - 16.5 16.5 0.0 0.1 0 0 0 26 0 0 0

2027 - 16.3 16.6 0.0 0.3 0 0 0 26 0 0 0

2030 - 16.2 16.5 0.0 0.3 0 0 0 26 0 0 0

2035 - 16.3 16.6 0.0 0.3 0 0 0 26 0 0 0

PM2.5

2017 10.8 - - - - - - - - - - -

2022 - 10.3 10.3 0.0 0.1 0 0 0 26 0 0 0

2027 - 10.1 10.2 0.0 0.2 0 0 0 26 0 0 0

2030 - 10.0 10.1 0.0 0.2 0 0 0 26 0 0 0

2035 - 10.1 10.2 0.0 0.2 0 0 0 26 0 0 0







1.6μg/m3 (4% of the 40μg/m3 AQO) at a receptor close to the M4. The maximum

total concentration within West Drayton with the DCO Project is 44.0μg/m3, which

is above the AQO. The AQO is also predicted to be exceeded in the future

baseline. Of the 26 receptors modelled in West Drayton, 22 are predicted to

experience negligible impacts, with two predicted to experience slight adverse

impacts, and two predicted to experience moderate adverse impacts. With the

CURED sensitivity test, 15 are predicted to experience negligible impacts, six are

predicted to experience slight adverse impacts and five are predicted to

experience moderate adverse impacts.




is below the AQO. Of the 26 receptors modelled in West Drayton, 23 are predicted

to experience negligible impacts, with three predicted to experience slight adverse

impacts. With the CURED sensitivity test, 10 are predicted to experience negligible

impacts, 14 are predicted to experience slight adverse impacts and two are

predicted to experience moderate adverse impacts.




is below the AQO. All 26 receptors modelled in West Drayton in 2030 are

predicted to experience negligible impacts. With the CURED sensitivity test, 16 are

predicted to experience negligible impacts, nine are predicted to experience slight

adverse impacts and one is predicted to experience a moderate adverse impact.




is below the AQO. Of the 26 receptors modelled in West Drayton in 2035, 23 are

predicted to experience negligible impacts, with three predicted to experience

slight adverse impacts. With the CURED sensitivity test, 15 are predicted to

experience negligible impacts, five are predicted to experience slight adverse

impacts and six are predicted to experience moderate adverse impacts.


to the M4. Annual mean PM10 and PM2.5 concentrations are predicted to be well

below the annual mean AQOs at all receptors in West Drayton in all modelled

years both without and with the DCO Project.


0.1μg/m3 for PM10 and PM2.5 in 2022 at receptors close to the M4, to 0.3μg/m3 and



0.2μg/m3 for PM10 and PM2.5 respectively in 2035. All 26 receptors modelled in

West Drayton are predicted to experience negligible impacts in all years.

Sipson



likely air quality impacts and total concentrations, within Sipson. NO2





Table 7.28: Dispersion modelling results for Sipson


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 35.5 - - - - - - - - - - -

2022 - 27.9 28.3 0.1 0.6 0 0 0 31 0 0 0

2027 - 21.1 22.8 1.5 5.1 0 0 0 7 20 4 0

2030 - 18.8 20.6 1.5 4.9 0 0 0 6 19 6 0

2035 - 19.1 21.0 1.9 5.2 0 0 0 3 11 17 0

PM10

2017 15.7 - - - - - - - - - - -

2022 - 15.2 15.3 0.0 0.1 0 0 0 31 0 0 0

2027 - 15.1 15.2 0.0 0.2 0 0 0 31 0 0 0

2030 - 15.0 15.2 0.0 0.2 0 0 0 31 0 0 0

2035 - 15.1 15.2 0.0 0.2 0 0 0 31 0 0 0

PM2.5

2017 10.0 - - - - - - - - - - -

2022 - 9.6 9.7 0.0 0.0 0 0 0 31 0 0 0

2027 - 9.4 9.5 0.0 0.1 0 0 0 31 0 0 0

2030 - 9.4 9.5 0.0 0.2 0 0 0 31 0 0 0

2035 - 9.4 9.5 0.0 0.2 0 0 0 31 0 0 0







0.6μg/m3 (2% of the 40μg/m3 AQO) at a receptor close to Sipson Way. The

maximum total concentration within Sipson with the DCO Project is 28.3μg/m3,

which is below the AQO. All 31 receptors modelled in Sipson are predicted to

experience negligible impacts in 2022. This remains the case with the CURED

sensitivity test.


5.1μg/m3 (13% of the 40μg/m3 AQO) at a receptor close to Harmondsworth Lane.

The maximum total concentration within Sipson with the DCO Project is

22.8μg/m3, which is below the AQO. Of the 31 receptors modelled in Sipson in

2027, seven are predicted to experience negligible impacts, with 20 predicted to

experience slight adverse impacts and four, moderate adverse impacts. With the

CURED sensitivity test, one slight adverse impact is reduced to negligible.


4.9μg/m3 (12% of the 40μg/m3 AQO). The maximum total concentration within

Sipson with the DCO Project is 20.6μg/m3, which is below the AQO. Of the 31

receptors modelled in Sipson in 2030, six are predicted to experience negligible

impacts, with 19 predicted to experience slight adverse impacts and six, moderate

adverse impacts. With the CURED sensitivity test, eight are predicted to

experience negligible impacts, with 20 predicted to experience slight adverse

impacts and three predicted to experience moderate adverse impacts.



Sipson with the DCO Project is 21.0μg/m3, which is below the AQO. Of the 31

receptors modelled in Sipson in 2035, three are predicted to experience negligible

impacts, with 11 predicted to experience slight adverse impacts and 17 predicted

to experience moderate adverse impacts. With the CURED sensitivity test, seven

are predicted to experience negligible impacts, 19 are predicted to experience

slight adverse impacts and five are predicted to experience moderate adverse

impacts.

7.10.48 Annual mean PM10 and PM2.5 concentrations are predicted to be well below the

annual mean AQOs at all receptors in Sipson in all modelled years both without

and with the DCO Project.

7.10.49 The maximum predicted increases in annual mean concentrations range from

0.1μg/m3 for PM10 and below 0.0μg/m3 for PM2.5 in 2022, to 0.2μg/m3 for both

PM10 and PM2.5 in 2035. All 31 receptors modelled in Sipson are predicted to

experience negligible impacts in all years.



Harlington



likely air quality impacts and total concentrations, within Harlington. NO2





Table 7.29: Dispersion modelling results for Harlington


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 52.0 - - - - - - - - - - -

2022 - 42.1 42.7 0.2 1.0 0 0 0 18 1 0 1

2027 - 30.8 30.8 -0.4 4.3 0 0 0 17 2 1 0

2030 - 26.7 27.0 0.3 3.7 0 0 0 17 3 0 0

2035 - 26.9 27.1 0.2 3.6 0 0 0 15 5 0 0

PM10

2017 17.4 - - - - - - - - - - -

2022 - 16.9 17.0 0.0 0.2 0 0 0 20 0 0 0

2027 - 16.7 16.7 -0.1 0.5 0 0 0 20 0 0 0

2030 - 16.6 16.7 0.0 0.4 0 0 0 20 0 0 0

2035 - 16.7 16.6 -0.1 0.4 0 0 0 20 0 0 0

PM2.5

2017 11.1 - - - - - - - - - - -

2022 - 10.6 10.6 0.0 0.1 0 0 0 20 0 0 0

2027 - 10.3 10.3 0.0 0.3 0 0 0 20 0 0 0

2030 - 10.2 10.2 0.0 0.3 0 0 0 20 0 0 0

2035 - 10.2 10.2 0.0 0.2 0 0 0 20 0 0 0







1.0μg/m3 (3% of the 40μg/m3 AQO) at a receptor close to the A408 Sipson Road.

The maximum total concentration within Harlington with the DCO Project is

42.7μg/m3, which is above the AQO. Of the 20 receptors modelled in Harlington,

18 are predicted to experience negligible impacts in 2022, with one predicted to

experience a slight adverse impact and one predicted to experience a substantial

adverse impact. With the CURED sensitivity test, 14 are predicted to experience

negligible impacts, five are predicted to experience slight adverse impacts and one

is predicted to experience a substantial adverse impact.



Harlington with the DCO Project is 30.8μg/m3, which is below the AQO. Of the 20

receptors modelled in Harlington, 17 are predicted to experience negligible

impacts in 2027, with two predicted to experience slight adverse impacts and one

predicted to experience a moderate adverse impact. With the CURED sensitivity

test, one slight adverse impact is increased to moderate adverse.





impacts in 2030, with three predicted to experience slight adverse impacts. With

the CURED sensitivity test, one slight adverse impact is increased to moderate

adverse.





impacts in 2035, with five predicted to experience slight adverse impacts. With the

CURED sensitivity test, 14 are predicted to experience negligible impacts, and six

are predicted to experience slight adverse impacts.



below the annual mean AQOs at all receptors in Harlington in all modelled years

both without and with the DCO Project.


0.2μg/m3 and 0.1μg/m3 for PM10 and PM2.5 respectively in 2022, to 0.4μg/m3 and

0.2μg/m3 in 2035. All twenty receptors modelled in Harlington are predicted to

experience negligible impacts in all years.



Hayes



likely air quality impacts and total concentrations, within Hayes. NO2


Figure 7.20, Volume 2.



Table 7.30: Dispersion modelling results for Hayes


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 53.4 - - - - - - - - - - -

2022 - 42.0 42.5 0.2 0.6 0 0 0 12 3 0 0

2027 - 30.8 30.8 -0.1 0.5 0 0 0 15 0 0 0

2030 - 27.0 27.1 0.1 0.3 0 0 0 15 0 0 0

2035 - 27.3 27.5 0.1 0.5 0 0 0 15 0 0 0

PM10

2017 15.3 - - - - - - - - - - -

2022 - 14.8 14.9 0.0 0.2 0 0 0 15 0 0 0

2027 - 14.7 14.5 -0.2 0.6 0 0 0 15 0 0 0

2030 - 14.6 15.3 0.0 1.5 0 0 0 15 0 0 0

2035 - 14.6 15.6 -0.2 1.8 0 0 0 15 0 0 0

PM2.5

2017 10.0 - - - - - - - - - - -

2022 - 9.5 9.5 0.0 0.1 0 0 0 15 0 0 0

2027 - 9.3 9.3 -0.1 0.4 0 0 0 15 0 0 0

2030 - 9.2 9.7 0.1 1.0 0 0 0 15 0 0 0

2035 - 9.2 9.9 -0.1 1.1 0 0 0 15 0 0 0







0.6μg/m3 (2% of the 40μg/m3 AQO) at a receptor close to the M4 and the A437

High Street. The maximum total concentration within Hayes with the DCO Project

is 42.5μg/m3, which is above the AQO. Of the 15 receptors modelled in Hayes, 12

are predicted to experience negligible impacts in 2022, with three predicted to

experience slight adverse impacts. With the CURED sensitivity test, seven are

predicted to experience negligible impacts, three are predicted to experience slight

adverse impacts and five are predicted to experience substantial adverse impacts.

7.10.59 After 2022, the maximum predicted increase in annual mean NO2 concentration is

0.5μg/m3 (2027 and 2035). The maximum annual mean concentration predicted

with the DCO Project is 30.8μg/m3, 27.1μg/m3 and 27.5μg/m3 in 2027, 2030 and

2035 respectively. After 2022, all receptors modelled are predicted to experience

annual mean concentrations below the AQO of 40μg/m3 with and without the DCO

Project. All 15 modelled receptors are predicted to experience negligible impacts

after 2022. This remains unchanged with the CURED sensitivity test.


to the M4 and the A437 High Street. Annual mean PM10 and PM2.5 concentrations

are predicted to be well below the annual mean AQOs at all receptors in Hayes in

all modelled years both without and with the DCO Project.


0.1μg/m3 in 2022 to below 0.0μg/m3 in 2035 for PM10. Maximum predicted

increases in annual mean concentrations for PM2.5 are below 0.0μg/m3 for all years

modelled. All 15 receptors modelled in Hayes are predicted to experience

negligible impacts for all years.

Cranford Cross



likely air quality impacts and total concentrations, within Cranford Cross. NO2





Table 7.31: Dispersion modelling results for Cranford Cross


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 36.2 - - - - - - - - - - -

2022 - 28.0 28.3 0.2 0.4 0 0 0 13 0 0 0

2027 - 21.7 21.0 1.1 1.1 0 0 0 13 0 0 0

2030 - 19.6 19.7 1.3 1.3 0 0 0 13 0 0 0

2035 - 19.5 19.4 1.8 1.8 0 0 0 13 0 0 0

PM10

2017 14.5 - - - - - - - - - - -

2022 - 14.1 14.1 0.0 0.1 0 0 0 13 0 0 0

2027 - 13.9 13.9 0.1 0.1 0 0 0 13 0 0 0

2030 - 13.8 13.8 0.1 0.1 0 0 0 13 0 0 0

2035 - 13.8 13.9 0.2 0.2 0 0 0 13 0 0 0

PM2.5

2017 9.5 - - - - - - - - - - -

2022 - 9.1 9.1 0.0 0.1 0 0 0 13 0 0 0

2027 - 8.8 8.8 0.1 0.1 0 0 0 13 0 0 0

2030 - 8.8 8.8 0.1 0.1 0 0 0 13 0 0 0

2035 - 8.8 8.8 0.1 0.1 0 0 0 13 0 0 0






7.10.63 The maximum predicted annual mean NO2 concentrations occur at receptors close

to the A4 Bath Road. The maximum annual mean concentration predicted with the

DCO Project is 28.3μg/m3, 21.0μg/m3, 19.7μg/m3 and 19.4μg/m3 in 2022, 2027,

2030 and 2035 respectively and is therefore below the AQO of 40μg/m3 in all

modelled years.


0.4μg/m3 in 2022 to 2.2μg/m3 in 2035. All 13 receptors modelled in Cranford Cross

are predicted to experience negligible impacts for all years. This conclusion

remains the case with the CURED sensitivity scenario.


to the A4 Bath Road. Annual mean PM10 and PM2.5 concentrations are predicted to

be well below the annual mean AQOs at all receptors in Cranford Cross in all


7.10.66 The maximum predicted increases in annual mean concentrations are 0.1μg/m3

for PM10 and PM2.5 for all years. All 13 receptors modelled in Cranford Cross are

predicted to experience negligible impacts for all years.

Cranford



likely air quality impacts and total concentrations, within Cranford. NO2





Table 7.32: Dispersion modelling results for Cranford


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 49.0 - - - - - - - - - - -

2022 - 37.4 37.6 0.2 0.4 0 0 0 14 0 0 0

2027 - 27.9 28.6 0.2 0.7 0 0 0 14 0 0 0

2030 - 24.5 24.9 0.3 0.4 0 0 0 14 0 0 0

2035 - 24.6 25.1 0.4 0.5 0 0 0 14 0 0 0

PM10

2017 16.4 - - - - - - - - - - -

2022 - 15.9 15.9 0.0 0.0 0 0 0 14 0 0 0

2027 - 15.7 15.8 0.0 0.1 0 0 0 14 0 0 0

2030 - 15.7 15.7 0.0 0.0 0 0 0 14 0 0 0

2035 - 15.7 15.7 0.0 0.0 0 0 0 14 0 0 0

PM2.5

2017 10.6 - - - - - - - - - - -

2022 - 10.0 10.1 0.0 0.0 0 0 0 14 0 0 0

2027 - 9.8 9.8 0.0 0.0 0 0 0 14 0 0 0

2030 - 9.7 9.7 0.0 0.0 0 0 0 14 0 0 0

2035 - 9.7 9.8 0.0 0.0 0 0 0 14 0 0 0







0.4μg/m3 (1% of the 40μg/m3 AQO) at a receptor close to the A4 Bath Road and

the A312 The Parkway. The maximum total concentration within Cranford with the

DCO Project is 37.6μg/m3, which is below the AQO. All 14 receptors modelled in

Cranford are predicted to experience negligible impacts in 2022. With the CURED

sensitivity test, one receptor is predicted to experience a slight adverse impact.


0.7μg/m3 (2% of the 40μg/m3 AQO) at a receptor close to the A4 Bath Road and

the A312 The Parkway. The maximum total concentration within Cranford with the

DCO Project is 28.6μg/m3, which is below the AQO. All 14 receptors modelled in

Cranford are predicted to experience negligible impacts in 2027. With the CURED

sensitivity test, two receptors are predicted to experience a slight adverse impact.

7.10.70 In modelled scenarios after 2027, the maximum predicted increase in annual

mean concentration ranges from 0.4μg/m3 in 2030 to 0.5μg/m3 in 2035. All

fourteen modelled receptors are predicted to experience negligible impacts after

2027. This remains unchanged with the CURED sensitivity test.


to the A4 Bath Road and the A312 The Parkway. Annual mean PM10 and PM2.5

concentrations are predicted to be well below the annual mean AQOs at all

receptors in Cranford in all modelled years both without and with the DCO Project.

7.10.72 The maximum predicted increases in annual mean concentrations are below

0.0μg/m3 for PM10 and PM2.5 for all years modelled, except in 2027 when the

maximum predicted increases in annual mean concentration is 0.1μg/m3 for PM10.

All 14 receptors modelled in Cranford are predicted to experience negligible

impacts for all years.

Heston



likely air quality impacts and total concentrations, within Heston. NO2





Table 7.33: Dispersion modelling results for Heston


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 57.0 - - - - - - - - - - -

2022 - 43.7 44.0 0.1 0.5 0 0 0 13 3 1 0

2027 - 31.9 32.0 0.3 0.3 0 0 0 17 0 0 0

2030 - 27.7 27.9 0.3 0.3 0 0 0 17 0 0 0

2035 - 27.9 28.2 0.3 0.4 0 0 0 17 0 0 0

PM10

2017 17.4 - - - - - - - - - - -

2022 - 16.8 16.8 0.0 0.1 0 0 0 17 0 0 0

2027 - 16.6 16.6 0.0 0.0 0 0 0 17 0 0 0

2030 - 16.6 16.6 0.0 0.0 0 0 0 17 0 0 0

2035 - 16.6 16.6 0.0 0.0 0 0 0 17 0 0 0

PM2.5

2017 11.1 - - - - - - - - - - -

2022 - 10.5 10.5 0.0 0.0 0 0 0 17 0 0 0

2027 - 10.2 10.2 0.0 0.0 0 0 0 17 0 0 0

2030 - 10.2 10.2 0.0 0.0 0 0 0 17 0 0 0

2035 - 10.2 10.2 0.0 0.0 0 0 0 17 0 0 0








total concentration within Heston with the DCO Project is 44.0μg/m3, which is

above the AQO. Of the 17 receptors modelled in Heston, 13 are predicted to

experience negligible impacts in 2022, with three predicted to experience slight

adverse impacts and one predicted to experience a moderate adverse impact.

With the CURED sensitivity test, four negligible impacts are increased to slight

adverse, and one slight adverse impact is increased to moderate adverse.

7.10.75 In modelled scenarios after 2022, the maximum predicted increase in annual

mean concentration range from 0.3μg/m3 in 2027 to 0.4μg/m3 in 2035. The

maximum annual mean concentration predicted with the DCO Project is

32.0μg/m3, 27.9μg/m3 and 28.2μg/m3 in 2027, 2030 and 2035 respectively. In

modelled scenarios after 2022, all receptors are predicted to experience annual

mean concentrations below the AQO of 40μg/m3 with and without the DCO

Project. All 17 modelled receptors are predicted to experience negligible impacts

after 2022. This remains unchanged with the CURED sensitivity test.



below the annual mean AQOs at all receptors in Heston in all modelled years both

without and with the DCO Project.

7.10.77 The maximum predicted increases in annual mean PM concentrations are below

0.0μg/m3 for PM10 and PM2.5 for all years modelled, except in 2022 when the

maximum predicted increases in annual mean concentration is 0.1μg/m3 for PM10.

All seventeen receptors modelled in Heston are predicted to experience negligible

impacts for all years.




likely air quality impacts and total concentrations, within Hounslow (Central and

South). NO2 concentrations with the DCO Project and impacts are shown in

Figure 7.27 and Figure 7.28, Volume 2.



Table 7.34: Dispersion modelling results for Hounslow (Central and South)


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 43.1 - - - - - - - - - - -

2022 - 34.5 34.8 0.0 0.2 0 0 0 6 0 0 0

2027 - 25.4 26.2 0.0 0.9 0 0 0 6 0 0 0

2030 - 22.5 23.3 0.0 0.8 0 0 0 6 0 0 0

2035 - 22.8 23.2 0.0 0.4 0 0 0 6 0 0 0

PM10

2017 16.2 - - - - - - - - - - -

2022 - 15.7 15.7 0.0 0.0 0 0 0 6 0 0 0

2027 - 15.5 15.6 0.0 0.1 0 0 0 6 0 0 0

2030 - 15.5 15.6 0.0 0.1 0 0 0 6 0 0 0

2035 - 15.5 15.6 0.0 0.0 0 0 0 6 0 0 0

PM2.5

2017 10.4 - - - - - - - - - - -

2022 - 9.9 9.9 0.0 0.0 0 0 0 6 0 0 0

2027 - 9.6 9.7 0.0 0.0 0 0 0 6 0 0 0

2030 - 9.6 9.6 0.0 0.1 0 0 0 6 0 0 0

2035 - 9.6 9.6 0.0 0.0 0 0 0 6 0 0 0







to the A315 London Road. The maximum annual mean concentration predicted at

a modelled receptor with the DCO Project is 34.8μg/m3, 26.2μg/m3, 23.3μg/m3 and

23.2μg/m3 in 2022, 2027, 2030 and 2035 respectively and is therefore below the

AQO of 40μg/m3 in all modelled years.


0.2μg/m3 in 2022 to 0.9μg/m3 in 2027. All six receptors modelled in Hounslow

(Central and South) are predicted to experience negligible impacts for all years.

With the CURED sensitivity test, one receptor is predicted to experience a slight

adverse impact in 2027.

7.10.81 Annual mean PM10 and PM2.5 concentrations are predicted to be well below the

annual mean AQOs at all receptors in Hounslow (Central and South) in all



0.0μg/m3 for PM10 and PM2.5 for most years modelled. The maximum predicted

increases in annual mean concentrations are 0.1μg/m3 for PM10 in 2027 and 2030,

and for PM2.5 in 2030. All six receptors modelled in Hounslow (Central and South)

are predicted to experience negligible impacts for all years.

Hounslow (West and Heath)



likely air quality impacts and total concentrations, within Hounslow (West and

Heath). NO2 concentrations with the DCO Project and impacts are shown in

Figure 7.29 and Figure 7.30, Volume 2.



Table 7.35: Dispersion modelling results for Hounslow (West and Heath)


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 47.7 - - - - - - - - - - -

2022 - 36.6 36.7 0.0 0.6 0 0 0 24 0 0 0

2027 - 27.3 28.3 0.0 0.9 0 0 0 24 0 0 0

2030 - 24.2 24.8 0.0 0.6 0 0 0 24 0 0 0

2035 - 24.3 24.9 0.0 0.6 0 0 0 24 0 0 0

PM10

2017 16.6 - - - - - - - - - - -

2022 - 16.1 16.1 0.0 0.0 0 0 0 24 0 0 0

2027 - 15.9 16.0 0.0 0.1 0 0 0 24 0 0 0

2030 - 15.9 15.9 0.0 0.1 0 0 0 24 0 0 0

2035 - 15.9 15.9 0.0 0.1 0 0 0 24 0 0 0

PM2.5

2017 10.7 - - - - - - - - - - -

2022 - 10.1 10.2 0.0 0.0 0 0 0 24 0 0 0

2027 - 9.9 10.0 0.0 0.1 0 0 0 24 0 0 0

2030 - 9.8 9.9 0.0 0.0 0 0 0 24 0 0 0

2035 - 9.9 9.9 0.0 0.0 0 0 0 24 0 0 0







to the A4 Bath Road. The maximum annual mean concentration predicted at a

modelled receptor with the DCO Project is 36.7μg/m3, 28.3μg/m3, 24.8μg/m3 and

24.9μg/m3 in 2022, 2027, 2030 and 2035 respectively and is therefore below the

AQO of 40μg/m3 in all modelled years.

7.10.85 The maximum predicted increase in annual mean concentration is 0.6μg/m3 in all

years modelled, except in 2027 when it is predicted to be to 0.9μg/m3. All 24

receptors modelled in Hounslow (West and Heath) are predicted to experience

negligible impacts for all years. With the CURED sensitivity test, two receptors are

predicted to experience slight adverse impacts in 2022, three receptors are

predicted to experience slight adverse impacts in 2027, and one receptor is

predicted to experience a slight adverse impact in 2030 and 2035.


to the A3063 Wellington Road. Annual mean PM10 and PM2.5 concentrations are

predicted to be well below the annual mean AQOs at all receptors in Hounslow

(West and Heath) in all modelled years both without and with the DCO Project.



increases in annual mean concentrations are 0.1μg/m3 for PM10 in 2027, 2030 and

2035 and for PM2.5 in 2027. All twenty-four receptors modelled in Hounslow (West

and Heath) are predicted to experience negligible impacts for all years.

Feltham North



likely air quality impacts and total concentrations, within Feltham North. NO2





Table 7.36: Dispersion modelling results for Feltham North


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 47.2 - - - - - - - - - - -

2022 - 36.4 36.7 0.3 0.5 0 0 0 12 0 0 0

2027 - 27.7 28.0 -0.3 0.6 0 0 0 12 0 0 0

2030 - 24.5 24.8 -0.1 0.4 0 0 0 12 0 0 0

2035 - 24.6 25.4 0.7 0.7 0 0 0 12 0 0 0

PM10

2017 15.6 - - - - - - - - - - -

2022 - 15.0 15.0 0.0 0.0 0 0 0 12 0 0 0

2027 - 14.8 14.9 0.0 0.1 0 0 0 12 0 0 0

2030 - 14.8 14.8 0.0 0.0 0 0 0 12 0 0 0

2035 - 14.8 14.8 0.0 0.1 0 0 0 12 0 0 0

PM2.5

2017 10.1 - - - - - - - - - - -

2022 - 9.6 9.6 0.0 0.0 0 0 0 12 0 0 0

2027 - 9.4 9.4 0.0 0.0 0 0 0 12 0 0 0

2030 - 9.3 9.3 0.0 0.0 0 0 0 12 0 0 0

2035 - 9.3 9.3 0.0 0.0 0 0 0 12 0 0 0







to the A30 Great South-West Road. The maximum annual mean concentration

predicted with the DCO Project is 37.6μg/m3, 28.0μg/m3, 24.8μg/m3 and 25.4μg/m3

in 2022, 2027, 2030 and 2035 respectively and is therefore below the AQO of

40μg/m3 in all modelled years.


0.5μg/m3 in 2022 to 0.7μg/m3 in 2035. All twelve receptors modelled in Feltham

North are predicted to experience negligible impacts for all years. With the CURED

sensitivity test, one receptor is predicted to experience a slight adverse impact in

2022, 2027 and 2035.


to the A315 Staines Road. Annual mean PM10 and PM2.5 concentrations are

predicted to be well below the annual mean AQOs at all receptors in Feltham

North in all modelled years both without and with the DCO Project.

7.10.92 The maximum predicted increases in annual mean PM concentrations are below


increases in annual mean concentrations are 0.1μg/m3 for PM10 in 2027 and 2035.

All twelve receptors modelled in Feltham North are predicted to experience


Bedfont



likely air quality impacts and total concentrations, within Bedfont. NO2





Table 7.37: Dispersion modelling results for Bedfont


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 47.4 - - - - - - - - - - -

2022 - 35.4 35.7 0.2 0.4 0 0 0 12 0 0 0

2027 - 26.7 27.5 -0.8 1.1 0 0 0 12 0 0 0

2030 - 23.5 24.3 -0.5 1.1 0 0 0 12 0 0 0

2035 - 23.7 24.8 0.7 1.5 0 0 0 12 0 0 0

PM10

2017 15.1 - - - - - - - - - - -

2022 - 14.6 14.6 -0.2 0.0 0 0 0 12 0 0 0

2027 - 14.4 14.5 -0.1 0.2 0 0 0 12 0 0 0

2030 - 14.4 14.5 0.0 0.2 0 0 0 12 0 0 0

2035 - 14.4 14.5 0.0 0.2 0 0 0 12 0 0 0

PM2.5

2017 9.9 - - - - - - - - - - -

2022 - 9.4 9.4 -0.1 0.0 0 0 0 12 0 0 0

2027 - 9.2 9.3 0.0 0.1 0 0 0 12 0 0 0

2030 - 9.1 9.2 0.0 0.1 0 0 0 12 0 0 0

2035 - 9.1 9.2 0.0 0.1 0 0 0 12 0 0 0







to the A30 Great South-West Road and Stanwell Road. The maximum annual

mean concentration predicted with the DCO Project is 35.7μg/m3, 27.5μg/m3,

24.3μg/m3 and 24.8μg/m3 in 2022, 2027, 2030 and 2035 respectively and is

therefore below the AQO of 40μg/m3 in all modelled years.


0.4μg/m3 in 2022 to 1.5μg/m3 in 2035. All 12 receptors modelled in Bedfont are

predicted to experience negligible impacts for all years. With the CURED

sensitivity test, two receptors in 2027 and one in 2035 are predicted to experience

slight adverse impacts.


to the A30 Great South-West Road and Stanwell Road. Annual mean PM10 and

PM2.5 concentrations are predicted to be well below the annual mean AQOs at all

receptors in Bedfont in all modelled years both without and with the DCO Project.

7.10.97 The maximum predicted increases in annual mean PM concentrations are

0.2μg/m3 for PM10 and 0.1μg/m3 for PM2.5 in 2027, 2030 and 2035. All 12 receptors

modelled in Bedfont are predicted to experience negligible impacts for all years.

Stanwell



likely air quality impacts and total concentrations, within Stanwell. NO2





Table 7.38: Dispersion modelling results for Stanwell


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 44.0 - - - - - - - - - - -

2022 - 31.3 31.7 0.3 0.5 0 0 0 18 0 0 0

2027 - 23.2 24.1 0.1 0.9 0 0 0 18 0 0 0

2030 - 20.5 22.2 0.3 1.7 0 0 0 18 0 0 0

2035 - 20.5 22.3 1.0 1.9 0 0 0 18 0 0 0

PM10

2017 14.3 - - - - - - - - - - -

2022 - 13.8 13.8 -0.1 0.0 0 0 0 18 0 0 0

2027 - 13.6 13.7 0.0 0.1 0 0 0 18 0 0 0

2030 - 13.6 13.7 0.0 0.2 0 0 0 18 0 0 0

2035 - 13.6 13.7 0.1 0.2 0 0 0 18 0 0 0

PM2.5

2017 9.4 - - - - - - - - - - -

2022 - 9.0 9.0 0.0 0.0 0 0 0 18 0 0 0

2027 - 8.8 8.8 0.0 0.1 0 0 0 18 0 0 0

2030 - 8.7 8.8 0.0 0.1 0 0 0 18 0 0 0

2035 - 8.7 8.8 0.1 0.1 0 0 0 18 0 0 0







to the B37 Park Road. The maximum annual mean concentration predicted with

the DCO Project is 31.7μg/m3, 24.1μg/m3, 22.2μg/m3 and 22.3μg/m3 in 2022,

2027, 2030 and 2035 respectively and is therefore below the AQO of 40μg/m3 in

all modelled years.


0.5μg/m3 in 2022 to 1.9μg/m3 in 2035. All eighteen receptors modelled in Stanwell

are predicted to experience negligible impacts for all years. With the CURED


2035.


to the A30 London Road. Annual mean PM10 and PM2.5 concentrations are

predicted to be well below the annual mean AQOs at all receptors in Stanwell in all



below 0.0μg/m3 in 2022 and 0.2μg/m3 in 2035 for PM10, and from below 0.0μg/m3

in 2022 and 0.1μg/m3 in 2035 for PM2.5. All 18 receptors modelled in Stanwell are


Stanwell Moor



likely air quality impacts and total concentrations, within Stanwell Moor. NO2





Table 7.39: Dispersion modelling results for Stanwell Moor


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 40.4 - - - - - - - - - - -

2022 - 29.6 30.1 0.3 1.0 0 0 0 12 0 0 0

2027 - 22.4 22.3 -0.1 1.9 0 0 0 12 0 0 0

2030 - 19.8 20.7 -0.3 3.3 0 0 0 7 5 0 0

2035 - 19.9 21.0 0.1 3.5 0 0 0 7 5 0 0

PM10

2017 15.4 - - - - - - - - - - -

2022 - 14.9 15.0 0.0 0.1 0 0 0 12 0 0 0

2027 - 14.8 14.9 0.0 0.1 0 0 0 12 0 0 0

2030 - 14.8 15.0 -0.1 0.3 0 0 0 12 0 0 0

2035 - 14.9 15.1 -0.1 0.4 0 0 0 12 0 0 0

PM2.5

2017 9.8 - - - - - - - - - - -

2022 - 9.4 9.4 0.0 0.0 0 0 0 12 0 0 0

2027 - 9.2 9.3 0.0 0.1 0 0 0 12 0 0 0

2030 - 9.2 9.4 -0.1 0.2 0 0 0 12 0 0 0

2035 - 9.2 9.4 -0.1 0.2 0 0 0 12 0 0 0








Stanwell Moor with the DCO Project is 30.1μg/m3, which is below the AQO. All 12

receptors modelled in Stanwell Moor are predicted to experience negligible

impacts in 2022. This remains the case with the CURED sensitivity test.



Stanwell Moor with the DCO Project is 22.3μg/m3, which is below the AQO. All 12

receptors modelled in Stanwell Moor are predicted to experience negligible

impacts in 2027. This remains the case with the CURED sensitivity test.



Stanwell Moor with the DCO Project is 20.7μg/m3, which is below the AQO. Of the

12 receptors modelled in Stanwell Moor, seven are predicted to experience

negligible impacts, with five slight adverse impacts. One of the slight adverse

impact is increased to moderate adverse under the CURED sensitivity test.



Stanwell Moor with the DCO Project is 21.0μg/m3, which is below the AQO. Of the

12 receptors modelled in Stanwell Moor, seven are predicted to experience

negligible impacts, with five slight adverse impacts. Two of the slight adverse

impacts are increased to moderate adverse under the CURED sensitivity test.


to the A3044 Stanwell Moor Road. Annual mean PM10 and PM2.5 concentrations

are predicted to be well below the annual mean AQOs at all receptors in Stanwell

Moor in all modelled years both without and with the DCO Project.


0.1μg/m3 in 2022 and 0.4μg/m3 in 2035 for PM10, and from below 0.0μg/m3 in 2022

and 0.2μg/m3 in 2035 for PM2.5. All twelve receptors modelled in Stanwell Moor


Poyle



likely air quality impacts and total concentrations, within Poyle. NO2 concentrations

with the DCO Project and impacts are shown in Figure 7.39 and Figure 7.40,

Volume 2.



Table 7.40: Dispersion modelling results for Poyle


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 41.5 - - - - - - - - - - -

2022 - 29.0 29.3 0.2 0.3 0 0 0 12 0 0 0

2027 - 22.5 22.3 -0.2 2.1 0 0 0 12 0 0 0

2030 - 20.1 20.7 0.1 2.1 0 0 0 12 0 0 0

2035 - 20.2 21.1 0.3 2.1 0 0 0 12 0 0 0

PM10

2017 15.8 - - - - - - - - - - -

2022 - 15.3 15.3 0.0 0.0 0 0 0 12 0 0 0

2027 - 15.2 15.2 -0.1 0.1 0 0 0 12 0 0 0

2030 - 15.2 15.2 -0.1 0.2 0 0 0 12 0 0 0

2035 - 15.2 15.3 0.0 0.2 0 0 0 12 0 0 0

PM2.5

2017 10.3 - - - - - - - - - - -

2022 - 9.8 9.8 0.0 0.0 0 0 0 12 0 0 0

2027 - 9.7 9.7 0.0 0.1 0 0 0 12 0 0 0

2030 - 9.6 9.7 0.0 0.1 0 0 0 12 0 0 0

2035 - 9.6 9.7 0.0 0.1 0 0 0 12 0 0 0







to Park Street. The maximum annual mean concentration predicted with the DCO

Project is 29.3μg/m3, 22.3μg/m3, 20.7μg/m3 and 21.1μg/m3 in 2022, 2027, 2030

and 2035 respectively and is therefore below the AQO of 40μg/m3 in all modelled

years.

7.10.112 The maximum predicted increases in annual mean NO2 concentrations range from

0.3μg/m3 in 2022 to 2.1μg/m3 in 2035. All 12 receptors modelled in Poyle are

predicted to experience negligible impacts for all years. With the CURED


2027 and 2030, and two receptors in 2035.


to Bath Road. Annual mean PM10 and PM2.5 concentrations are predicted to be

well below the annual mean AQOs at all receptors in Poyle in all modelled years

both without and with the DCO Project.


less than 0.0μg/m3 in 2022 to 0.2μg/m3 in 2035 for PM10, and from less than

0.0μg/m3 in 2022 to 0.1μg/m3 in 2035 for PM2.5. All 12 receptors modelled in Poyle


Colnbrook



likely air quality impacts and total concentrations, within Colnbrook. NO2





Table 7.41: Dispersion modelling results for Colnbrook


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 46.0 - - - - - - - - - - -

2022 - 30.8 31.3 0.0 0.5 0 0 0 12 0 0 0

2027 - 23.0 23.0 0.4 1.3 0 0 0 12 0 0 0

2030 - 20.1 20.2 0.5 1.1 0 0 0 12 0 0 0

2035 - 20.2 20.5 0.5 1.2 0 0 0 12 0 0 0

PM10

2017 16.2 - - - - - - - - - - -

2022 - 15.6 15.6 0.0 0.0 0 0 0 12 0 0 0

2027 - 15.5 15.6 0.0 0.0 0 0 0 12 0 0 0

2030 - 15.5 15.5 0.0 0.0 0 0 0 12 0 0 0

2035 - 15.5 15.6 0.0 0.1 0 0 0 12 0 0 0

PM2.5

2017 10.3 - - - - - - - - - - -

2022 - 9.7 9.7 0.0 0.0 0 0 0 12 0 0 0

2027 - 9.5 9.6 0.0 0.0 0 0 0 12 0 0 0

2030 - 9.5 9.5 0.0 0.0 0 0 0 12 0 0 0

2035 - 9.5 9.5 0.0 0.0 0 0 0 12 0 0 0







to Bridge Street. The maximum annual mean concentration predicted with the

DCO Project is 31.3μg/m3, 23.0μg/m3, 20.2μg/m3 and 20.5μg/m3 in 2022, 2027,

2030 and 2035 respectively and is therefore below the AQO of 40μg/m3 in all

modelled years.


0.5μg/m3 in 2022 to 1.2μg/m3 in 2035. All 12 receptors modelled in Colnbrook are

predicted to experience negligible impacts for all years. This remains the case with

the CURED sensitivity test.


to the junction between the High Street and Horton Road. Annual mean PM10 and

PM2.5 concentrations are predicted to be well below the annual mean AQOs at all

receptors in Colnbrook in all modelled years both without and with the DCO

Project.

7.10.119 The maximum predicted increases in annual mean concentrations range from less

than 0.0μg/m3 in 2022 to 0.1μg/m3 in 2035 for PM10. Maximum predicted increases

in annual mean concentrations are less than 0.0μg/m3 in all years modelled for

PM2.5. All twelve receptors modelled in Colnbrook are predicted to experience


Brands Hill



likely air quality impacts and total concentrations, within Brands Hill. NO2





Table 7.42: Dispersion modelling results for Brands Hill


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 61.6 - - - - - - - - - - -

2022 - 43.5 45.1 0.3 3.0 0 0 0 3 1 10 2

2027 - 32.1 31.8 -1.0 0.5 0 0 2 14 0 0 0

2030 - 27.9 27.7 -1.1 0.5 0 0 0 16 0 0 0

2035 - 27.9 28.0 -1.2 0.7 0 0 0 15 0 0 0

PM10

2017 17.3 - - - - - - - - - - -

2022 - 16.7 16.8 0.0 0.2 0 0 0 16 0 0 0

2027 - 16.5 16.5 -0.1 0.0 0 0 0 16 0 0 0

2030 - 16.5 16.5 -0.2 0.0 0 0 0 16 0 0 0

2035 - 16.6 16.5 -0.2 0.1 0 0 0 16 0 0 0

PM2.5

2017 11.0 - - - - - - - - - - -

2022 - 10.4 10.5 0.0 0.1 0 0 0 16 0 0 0

2027 - 10.2 10.2 -0.1 0.0 0 0 0 16 0 0 0

2030 - 10.1 10.1 -0.1 0.0 0 0 0 16 0 0 0

2035 - 10.1 10.1 -0.1 0.0 0 0 0 16 0 0 0







3.0μg/m3 (8% of the 40μg/m3 AQO) at a receptor close to the A4 Colnbrook

Bypass. The maximum total concentration within Brands Hill with the DCO Project

is 45.1μg/m3, which is above the AQO. Of the 16 receptors modelled in Brands

Hill, three are predicted to experience negligible impacts in 2022, with one

predicted to experience a slight adverse impact, 10 predicted to experience

moderate adverse impacts and two predicted to experience substantial adverse

impacts. With the CURED sensitivity test, two receptors are predicted to

experience negligible impacts, with two predicted to experience slight adverse

impacts, four predicted to experience moderate adverse impacts and eight

predicted to experience substantial adverse impacts.


0.5μg/m3 (1% of the 40μg/m3 AQO) at a receptor close to London Road. The

maximum total concentration within Brands Hill with the DCO Project is 31.8μg/m3,

which is below the AQO. Of the 16 receptors modelled in Brands Hill, 14 are

predicted to experience negligible impacts in 2027, with two predicted to

experience slight beneficial impacts. With the CURED sensitivity test, nine are

predicted to experience negligible impacts in 2027, with two predicted to

experience slight adverse impacts, one predicted to experience a moderate

adverse impact, four predicted to experience slight beneficial impacts and one

predicted to experience a moderate beneficial impact.



Brands Hill with the DCO Project is 27.7μg/m3, which is below the AQO. All of the

16 receptors modelled in Brands Hill are predicted to experience negligible

impacts in 2030. With the CURED sensitivity test, 12 are predicted to experience

negligible impacts in 2030, with four predicted to experience slight beneficial

impacts.



Brands Hill with the DCO Project is 28.0μg/m3, which is below the AQO. All of the

16 receptors modelled in Brands Hill are predicted to experience negligible

impacts in 2035. With the CURED sensitivity test, 11 are predicted to experience

negligible impacts in 2035, with one predicted to experience a slight adverse

impact, and four predicted to experience slight beneficial impacts.


to the junction between the A4 Colnbrook Bypass and London Road. Annual mean

PM10 and PM2.5 concentrations are predicted to be well below the annual mean

AQOs at all receptors in Brands Hill in all modelled years both without and with the

DCO Project.




0.2μg/m3 and 0.1μg/m3 for PM10 and PM2.5 respectively in 2022, to 0.1μg/m3 and

below 0.0μg/m3 in 2035. All sixteen receptors modelled in Brands Hill are


Iver and Richings Park



likely air quality impacts and total concentrations, within Iver and Richings Park.

NO2 concentrations with the DCO Project and impacts are shown in Figure 7.45

and Figure 7.46, Volume 2.



Table 7.43: Dispersion modelling results for Iver and Richings Park


Baseline Future

Baseline

With

DCO

Project

Maximum decrease

or minimum increase

Maximum

Increase

Subs.

Ben.

Mod.

Ben.

Slight

Ben.

Neg. Slight

Adv.

Mod.

Adv.

Subs.

Adv.

NO2

2017 58.5 - - - - - - - - - - -

2022 - 48.2 48.9 0.3 0.6 0 0 0 12 0 2 0

2027 - 35.8 36.1 0.6 0.6 0 0 0 14 0 0 0

2030 - 31.1 31.3 0.6 0.6 0 0 0 14 0 0 0

2035 - 31.5 31.7 0.6 0.6 0 0 0 14 0 0 0

PM10

2017 17.4 - - - - - - - - - - -

2022 - 17.0 17.0 0.0 0.1 0 0 0 14 0 0 0

2027 - 16.8 16.9 0.1 0.1 0 0 0 14 0 0 0

2030 - 16.8 16.9 0.1 0.1 0 0 0 14 0 0 0

2035 - 16.9 16.9 0.1 0.1 0 0 0 14 0 0 0

PM2.5

2017 11.1 - - - - - - - - - - -

2022 - 10.6 10.7 0.0 0.0 0 0 0 14 0 0 0

2027 - 10.4 10.5 0.0 0.0 0 0 0 14 0 0 0

2030 - 10.4 10.4 0.0 0.0 0 0 0 14 0 0 0

2035 - 10.4 10.4 0.0 0.0 0 0 0 14 0 0 0








total concentration within Iver and Richings Park with the DCO Project is

48.9μg/m3, which is above the AQO. Of the 14 receptors modelled in Iver and

Richings Park, 12 are predicted to experience negligible impacts in 2022, with two

predicted to experience moderate adverse impacts. With the CURED sensitivity

test, the two moderate adverse impacts are increased to substantial adverse

impacts.

7.10.129 In 2027, 2030 and 2035, the maximum predicted increase in annual mean NO2

concentration is 0.6μg/m3 (2% of the 40μg/m3 AQO) at a receptor close to the M4.

The maximum total concentration within Iver and Richings Park with the DCO

Project is 36.1μg/m3, 31.3μg/m3 and 31.7μg/m3 in 2027, 2030 and 2035

respectively. These concentrations are below the AQO. All 14 receptors modelled

in Iver and Richings Park, are predicted to experience negligible impacts in 2027,

2030 and 2035. With the CURED sensitivity test, one negligible impact is

increased to a slight adverse impact in 2027.



below the annual mean AQOs at all receptors in Iver and Richings Park in all


7.10.131 The maximum predicted increases in annual mean PM concentrations are

0.1μg/m3 for PM10 and below 0.0μg/m3 for PM2.5 for all years modelled. All

fourteen receptors modelled in Iver and Richings Park are predicted to experience


Summary results across the core AQO assessment area

7.10.132 Results are only considered in relation to NO2 in this section as negligible impacts

are predicted in relation to PM, as described above in relation to each community

area. The results presented are calculated using the Defra EFT. Results produced

using the CURED sensitivity test are provided in Appendix 7.1.

7.10.133 Table 7.44 presents a count of the number of Ordnance Survey address points at

which each impact descriptor is predicted, for each scenario. In every case, the

outputs from models run using 2017 meteorological data have been used, as they

consistently produced more ‘moderate’ and ‘substantial’ impacts compared to

2015 and 2016.

7.10.134 Owing to the use of Ordnance Survey AddressBase data as opposed to the

manual identification of selected representative receptor locations, it should be

noted that the reported number of address points by impact descriptor in Table

7.44 may not align entirely with the numbers reported in relation to each



community area. For example, in some cases, AddressBase data may not include

new development that has become operational since the data were published in

2018-2019.

Table 7.44: Address points within Core AQO Assessment Area by impact descriptor

Impact Descriptor Scenario

2022 2027 2030 2035

Substantial Adverse 1 0 0 0

Moderate Adverse 106 14 27 70

Slight Adverse 315 327 378 371

Negligible 145,030 145,105 145,047 145,011

Slight Beneficial 0 6 0 0

Moderate Beneficial 0 0 0 0

Substantial Beneficial 0 0 0 0

7.10.135 Table 7.45 presents a count of the number of AddressBase address points at

which each class of change in concentration is predicted, for each scenario. The

changes used in producing the table were the maxima when using either 2016 or

2017 meteorological data.

Table 7.45: Address point count by magnitude of change in concentration

Magnitude of Change in Annual Mean NO2 (µg/m³)

Scenario

2022 2027 2030 2035

>4.0 0 29 51 93

2.0 – 4.0 3 404 512 759

0.4 – 2.0 1,701 11,033 18,157 43,330

0.0 – 0.4 135,638 132,264 126,318 100,847

-0.4 – 0.0 8,110 1,552 376 367

-2.0 – -0.4 0 170 38 56

-4.0 – -2.0 0 0 0 0

<-4.0 0 0 0 0

7.10.136 Table 7.46 presents a count of the number of properties within each category as

defined in Table 2.2 of IAN 174/13 (Highways Agency, 2013a). The preliminary

status of the 2022 modelling should be noted. Further work will be undertaken on

the CTMP and CWTP and the modelling of road traffic impacts during the



construction phase. Results of the assessment using this refined data will be

presented in the ES. The approach detailed in IAN 174/13 (Highways Agency,

2013a) is not generally considered to apply to the construction phase of a project,

which by its nature is temporary and therefore does not affect the long-term ability

to meet the AQO or limit value. However, the results have been considered using

this approach in 2022 for consistency and to enable comparison across Phases.

Following the approach in IAN 174/13 (Highways Agency, 2013a), the DCO

Project is predicted to cause a small change at 33 receptors where the AQO is

exceeded already, or a new exceedance is created in 2022. No exceedances are

predicted in all other years assessed.

Table 7.46: Local air quality receptors informing significance

Magnitude of Change in Annual Mean NO2 (µg/m³)

Total Number of Receptors

2022 2027 2030 2035

A1 B2 A B A B A B

Large (>4.0) 0 0 0 0 0 0 0 0

Medium (2.0 – 4.0) 0 0 0 0 0 0 0 0

Small (0.4 – 2.0) 333 0 0 0 0 0 0 0

Notes: 1 Increase in NO2 concentration where the AQO is exceeded already, or creation of a new exceedance 2 Reduction in NO2 concentration where the AQO is exceeded already, or removal of an existing exceedance 3 If the EPUK/IAQM definition of negligible (0.2µg/m³), was used instead of the Highways Agency definition of

imperceptible (0.4µg/m³), there would be 79 address points where there is predicted to be a small increase in

NO2 concentration where the AQO is exceeded already, or creation of a new exceedance

7.10.137 Overall, as shown in Table 7.47, following the ‘Approach to be Adopted to

Evaluate Significant Local Air Quality Effects’ in IAN 174/13 (Highways Agency,

2013a), the scheme is judged to be not significant.

Table 7.47: Overall evaluation of local air quality (NO2) significance

Key Criteria Questions Yes/No

Justification

Is there a risk that

environmental standards will be

breached?

Yes Some AQO exceedances are predicted in 2022, but not in any of

the years 2027, 2030 or 2035.

Will there be a large change in

environmental conditions?

No Only small changes are predicted at locations where exceedances

of the annual mean NO2 AQO are predicted.

Will the effect continue for a

long time?

No The DCO Project is predicted to cause a small change at 33

receptors where the AQO is exceeded already, or a new

exceedance is created in 2022. No exceedances are predicted in



Key Criteria Questions Yes/No

Justification

all other years assessed.

Will many people be affected? No Only 33 of the 145,452 address points are predicted to experience

small increases in NO2 concentrations alongside an exceedance

of the AQO in 2022. It should also be noted that not all of these 33

properties are located along the SRN, which is the focus of the

IAN; 14 are along the SRN (ten next to the M4 and four next to the

M25), but 17 are along the A4 in Brands Hill and two are along the

A437 Dawley Road in Hayes.

Is there a risk that designated

sites, areas, or features will be

affected?

N/A Impacts on designated sites have not been assessed at this stage

Will it be difficult to avoid, or

reduce or repair or compensate

for the effect?

No It is anticipated that CTMP and CWTP, which will be accounted for

in the assessment carried out for the ES will ‘avoid or reduce…the

effect’ during the construction phase.

On Balance is the Overall Effect Significant?

No

Areas outside of the Core AQO Assessment Area

7.10.138 The tiered assessment of potential effects outside of the Core AQO Assessment

Area, as described in Section 7.7, has been carried out for all modelled years.

The assessment indicated that, given the predicted changes in road traffic flows as

a result of the DCO Project and the relationship of receptors to road links,

negligible impacts are predicted in relation to the annual mean NO2 AQO across

the majority of the FMA for which traffic data were provided.

7.10.139 The one area identified outside of the Core AQO Assessment Area where there

could potentially be non-negligible adverse impacts as a result of road traffic

associated with the DCO Project was the A308 and A332 corridor through Old

Windsor and Windsor.

7.10.140 In order to determine the magnitude of impacts in this area, discrete dispersion

modelling has been carried out, again using the base years 2015, 2016 and 2017.

This modelling has utilised the Defra mapped background concentrations with no

sectors removed (with national adjustment applied for 2016 and 2017 – see

Appendix 7.1) and has been verified using measured concentrations from the

Royal Borough of Windsor and Maidenhead automatic monitoring site MM2 and

diffusion tube monitoring sites WM04 and WM11, all located adjacent to the A308

or A332. Concentrations were predicted at worst-case roadside locations. The

modelling has incorporated the change in concentrations as a result of airside

emissions as well as the changes as a result of traffic emissions.



7.10.141 NO2 concentrations with the DCO Project and impacts are shown in Figure 7.47

and Figure 7.48, Volume 2. This dispersion modelling has predicted no

exceedances of any AQO in the discrete modelled area in any of the assessment

years (2022, 2027, 2030 and 2035), using either the Defra EFT or CURED

emission factors. The impact magnitude is predicted to be negligible at every

receptor for NO2 and PM in 2022, 2030 and 2035. In 2027, impacts are predicted

to be negligible at every receptor for all pollutants when using the Defra EFT

emission factors. Impacts are also predicted to be negligible at every receptor

when using the CURED sensitivity test emissions factors alongside 2017

meteorological data.

7.10.142 The tiered assessment of road traffic impacts associated with the DCO Project will

be repeated using the refined HHASAM traffic data available at the ES stage.

EU limit value compliance

7.10.143 Compliance with the NO2 annual mean EU limit value has been considered in line

with the methodology set out in Section 7.7 and Appendix 7.1.

7.10.144 As detailed in Section 7.7, predicted changes in NO2 concentrations are derived

from projected changes in traffic flow as a result of the DCO Project in key

assessment years during construction and operational phases. This data is based

upon a number of conservative assumptions which are set out in Section 7.8 and

Appendix 7.1. This is particularly true of the projected changes in traffic flow in

2022, during the initial construction phase of the DCO Project.

EU limit value compliance within the core AQO assessment area

7.10.145 The maximum predicted total annual mean NO2 concentrations along the key PCM

links within the Core AQO Assessment Area, across which pollutant

concentrations have been modelled, are presented in Table 7.48 to Table 7.50.

Locations are shown in Figure 7.2, Volume 2. Results produced using the

CURED sensitivity test are shown in Appendix 7.1. The CURED sensitivity test

results do not alter the conclusions presented here.

7.10.146 No exceedances of the limit value are predicted anywhere within the Core AQO

Assessment Area in 2027 or 2030. This is expected to remain the case in 2035,

due to continuing improvements in local air quality and background

concentrations, driven primarily by the improving emission performance of the

vehicle fleet. However, Defra has not produced PCM concentrations for years after

2030. As such, the assessment focuses on 2027 and 2030 only.

7.10.147 It is predicted that the DCO Project will not affect whether or not the limit value is

achieved in 2022 on most of the links within the Core AQO Assessment Area.

When using the 2017-base PCM concentrations, however, the DCO Project is



predicted to lead to an annual mean NO2 concentration above 40µg/m3 along link

36309 (the A30 Great South-West Road as it passes Hatton Cross), where the

concentration would have been below 40µg/m3 without the DCO Project. The PCM

projections indicate that the baseline concentration without the DCO Project will

exceed the limit value on this link in 2021, and that the concentration will reduce

by 2.2µg/m3 between 2022 and 2023, thus the limit value will be achieved on the

link in 2023 with or without the DCO Project. As such, it is predicted that the DCO

Project will lead to the limit value not being achieved on this link in the year 2022

only.

7.10.148 There are six other links where the limit value is predicted to be exceeded in 2022,

with or without the DCO Project. These all represent sections of the M4 (link

26012) or A312 (links 18727, 26914, 48810, 49028 and 73636). The most recent

PCM modelling suggests that the limit value will be achieved on the M4 link in

2023 and on all of the A312 links in 2024 at the latest. Bearing in mind the

increase predicted as a result of the DCO Project in 2022 on M4 link 26012

(0.9-1.0µg/m3), and the total concentration predicted by Defra in 2023 (38.9µg/m3),

it is considered that the NO2 concentration on this link will be below 40µg/m3 with

or without the DCO Project in 2023, or by 2024 at the latest. On the A312 links, the

highest predicted baseline PCM concentration in 2024 from Defra’s most recent

modelling is 39.3µg/m3 on link 48810; the increase as a result of the DCO Project

on this link is just 0.5µg/m3, thus the NO2 concentration in 2024 on this link will be

below 40µg/m3, with or without the DCO Project. The same is true for all of the

other A312 PCM links; when the DCO Project increment is added to the 2024

PCM baseline concentration the total NO2 concentration is below 40µg/m3. As

such, the NO2 concentration on all sections of the A312 will be below 40µg/m3 with

or without the DCO Project in 2024.

7.10.149 As such, it is concluded that the DCO Project can be expected to have a minimal

effect on the achievement of the NO2 annual mean limit value on individual PCM

links in the Core AQO Assessment Area. The DCO Project will only lead to the

concentration being above 40µg/m3 for one additional year on one single PCM link

(36309), and this is not the link with the highest concentration in the Core AQO

Assessment Area in the PCM modelling. The link with the highest concentration

within the Core AQO Assessment Area is 16112 (A4 Bath Road), at which

concentrations are projected to decrease in both 2027 and 2030. Concentrations

in a wider range of individual years will be assessed in the ES.



Table 7.48: NO2 annual mean EU limit value compliance in 2022

Census ID Road Annual Mean NO2 Concentration (µg/m3)

PCM171 Change With DCO Project

6123 A4 Bath Road East of Waggoners Roundabout 32.4 0.3 32.7

16112 A4 Bath Road (Heathrow Boulevard to Nobel Drive) 37.8 0.9 38.7

18727 A312 between M4 and Hayes Road 44.5 0.7 45.2

26914 A312 between High Street and M4 41.0 0.2 41.2

36309 A30 past Hatton Cross 39.3 1.2 40.6

48810 A312 between Pump Lane and A4020 44.5 0.5 45.0

49028 A312 North of A4020 40.0 0.5 40.5

56686 A312 between A30 and High Street 39.7 0.2 39.9

59008 A4 near Henlys Roundabout 38.7 0.5 39.2

73633 A30 West of A312 36.4 0.0 36.4

73636 A312 between Hayes Road and Pump Lane 44.5 0.6 45.1

36013 M4 Spur 36.2 2.1 38.4

75071 A4 Great West Road East of Jersey Road 37.7 0.1 37.9

78344 A4 Brands Hill 30.4 2.4 32.8

18487 M4 Near J3 36.2 1.1 37.2

26012 M4 East of Heston Road 41.5 0.9 42.4

6013 M4 East of J4 35.5 1.2 36.7

73446 A4020 The Broadway 31.3 0.2 31.5

1 This is the predicted baseline concentration from Defra’s 2019 NO2 projections data (2017 reference year) (Defra, 2019b)


Census ID

Road Annual Mean NO2 Concentration (µg/m3)



16112 A4 Bath Road (Heathrow Boulevard to Nobel Drive) 35.2 -3.4 31.8





49028 A312 North of A4020 29.9 0.3 30.2



Census ID

Road Annual Mean NO2 Concentration (µg/m3)




73633 A30 West of A312 28.7 0.9 29.6


36013 M4 Spur 28.5 5.3 33.7


78344 A4 Brands Hill 23.9 -0.7 23.2

18487 M4 Near J3 27.7 -0.1 27.6

26012 M4 East of Heston Road 30.6 -0.3 30.3

6013 M4 East of J4 27.3 0.9 28.2

73446 A4020 The Broadway 24.4 0.4 24.9





16112 A4 Bath Road (Heathrow Boulevard to Nobel Drive) 34.0 -4.4 29.6





49028 A312 North of A4020 26.1 0.4 26.5



73633 A30 West of A312 25.8 0.6 26.4


36013 M4 Spur 25.3 3.5 28.9


78344 A4 Brands Hill 21.5 -0.8 20.7

18487 M4 Near J3 24.2 0.2 24.5

26012 M4 East of Heston Road 26.0 0.0 26.0





6013 M4 East of J4 23.9 1.1 25.0

73446 A4020 The Broadway 22.0 0.4 22.4

Compliance outside of the core AQO assessment area

7.10.150 Beyond the Core AQO Assessment Area, the impact of the DCO Project on NO2

concentrations on key PCM links has been assessed through consideration of the

predicted changes in traffic flows as a result of the DCO Project on these links.

This assessment has focussed on the key road corridors between Heathrow and

Central London, namely the A4 and A40, where the PCM links with the highest

concentrations in the Greater London agglomeration zone are located. Initial

assessment of the potential impact on achievement of the limit value concentration

along these key corridors has focussed on the traffic model links that represent

these roads at the edge of the FMA, which is the geographic area of HHASAM in

which all trip movements are represented.

7.10.151 The traffic modelling carried out for the DCO Project predicts a reduction in total

vehicle flows of at least 100 AADT along the A40 at the edge of the FMA (at the

boundary of London Borough of Hammersmith and Fulham and Royal Borough of

Kensington and Chelsea) in all future year scenarios assessed. As such, the DCO

Project is expected to reduce total emissions along this section of the A40 towards

Central London, and thus will contribute towards the limit value being achieved as

soon as possible.

7.10.152 The outputs of the traffic modelling are more complex on the A4 as it passes

between London Borough of Hammersmith and Fulham and Royal Borough of

Kensington and Chelsea. Total vehicle flows are projected to increase as a result

of the DCO Project in 2022, but decrease in the years 2027, 2030 and 2035.

However, HDV flows are predicted to increase in the years 2027, 2030 and 2035.

7.10.153 On the basis of the traffic data, it is predicted that emissions, and resultant

concentrations, will increase marginally in the year 2022 with the DCO Project.

However, Defra’s latest PCM modelling predicts that the limit value concentration

of 40µg/m3 will be exceeded along this stretch of the A4 in the year 2022 with or

without the DCO Project, and that the concentration will be above 40µg/m3 until

2028 along the A4 as it passes Hammersmith. As a result, any temporary

increases in vehicle flows arising from the DCO Project in years prior to 2028 will

not affect the ability to meet the NO2 limit value on this link.



7.10.154 To consider the change in emissions on the A4 as a result of the DCO Project in

2027, 2030 and 2035, Defra’s EFT has been used to predict the total change in

emissions in each year considering reductions in LDVs and increases in HDVs.

PCM modelling focusses on predicting concentrations adjacent to sections of road

that are representative of a 100 m stretch and not within 25 m of a junction. As

such, a realistic free-flow speed of 50kph has been used when predicting

emissions. In each year, the outputs of this assessment indicate that the reduction

in LDVs will more than offset the additional emissions from the increase in HDVs.

Noting that the CURED sensitivity test only uplifts LDV emissions factors, it can be

expected that the same conclusion would be drawn were this emissions model to

be used instead of the EFT, i.e. that the reduction in light vehicle emissions would

more than offset the increases in heavy vehicle emissions in the years 2027, 2030

and 2035. The DCO Project is therefore expected to reduce emissions, and

resultant concentrations, along this section of the A4 towards Central London, and

will not delay the achievement of the limit value on this link.

7.10.155 Further consideration of the impact of the DCO Project on PCM compliance in

Central London, beyond the extent of the FMA, has focussed on the outputs of the

traffic demand models. The SAP document (and the Heathrow vehicle access

charge in particular) demonstrates how the Assessment Case is effective at

reducing private vehicle trips to / from Central London as it is well served by public

transport, including schemes like the Elizabeth line and the Piccadilly line upgrade.

Proposals for reduced Heathrow Express fares are predicted to further reduce

demand for private vehicle trips to / from central London. The 2035 DCO Project

scenario modelled in London Airports Surface Access Model (LASAM - the air

passenger surface access mode choice model) achieves a public transport mode

share of 54%. The total number of air passengers forecast to travel to and from

central London increases by just over 33% in the DCO Project scenario compared

to the future baseline. However, the forecast increase in public transport mode

share in Central London means that the number of air passengers using private

vehicle modes is forecast to reduce by 18%.

Compliance risk assessment

7.10.156 Consideration has also been given to compliance in the context of Highways

England’s Interim Advice Note (IAN) 175/13 - Risk assessment of compliance with

the EU Directive on ambient air quality and production of Scheme Air Quality

Action Plans. Specifically, the results set out above have been considered in terms

of the flow chart presented in Annex A of that document.

7.10.157 It should be noted that the IAN 175/13 (Highways Agency, 2013b) risk assessment

is designed to be applied only to the operational impacts of a scheme, not to

impacts arising during the construction phase. It has been applied to the



construction impacts in this case for completeness and is considered a helpful way

of presenting the results.

7.10.158 The assessment results predict no exceedances of the limit value within the Core

AQO Assessment Area in the assessment years 2027 and 2030, with or without

the DCO Project. The assessment results predict that the DCO Project will reduce

concentrations on key links extending into Central London, including the A40. As

such, using the flow chart, it is concluded that the DCO Project is Low Risk.

7.10.159 In 2022, during the construction phase, exceedances of the limit values are

predicted within the Core AQO Assessment Area without the DCO Project. In

2022, projected changes in pollutant concentrations due to the Project are

principally driven by construction traffic.



7.10.161 Table 7.48 demonstrates that the DCO Project will lead to increases in

concentrations on those PCM links where the predicted concentration is above

40µg/m3, and that the increase will be greater than 0.4µg/m3 (1%). Therefore,

using the flow chart, based on a conservative assessment that has not yet

accounted for the final CTMP and CWTP, preliminary findings are that the scheme

is High Risk when considering the construction impacts in 2022, as modelled.

7.10.162 However, as has been stated in Section 7.8, there are limitations to the predicted

traffic flows used for the 2022 construction assessment, such that changes in

traffic flows are anticipated to reduce following application of the suite of measures

to be developed further for the ES which will constitute the Action Plan for the

construction phase. As such, these results should be considered preliminary, but

will inform development of measures to manage construction traffic flows in

advance of the production of the ES, in order to ensure that impacts during

construction are reduced as far as practicable. It must also be noted that the

scheme will not result in a compliant zone becoming non-compliant, or delay the

date predicted by Defra for achieving compliance in the Greater London

agglomeration zone.

Operational odour

7.10.163 In general, the risk-based assessment shows that community areas towards the

south and south-east of the Airport are less likely to have odour emissions

dispersed towards them (including Feltham North and Bedfont). This is because

prevailing winds at Heathrow are predominantly from the west, south-west and, to

a smaller extent, the north-east.

7.10.164 Generally, the level of odour impacts will decrease with increasing distance from

the source, i.e. those areas closest to the airfield activity introduced around the

North West Runway have the potential to experience higher odour impacts than

those at greater distance.

7.10.165 During Phase 1, it is likely that additional potential odour impacts from operational

activities will be negligible because, when compared with current airport

operations, there is a relatively small change in ATMs compared to the existing

baseline.

7.10.166 The DCO Project will have the effect of distributing potential odour impacts over a

wider area than at present due to increased airside activity. Members of

communities close to the existing Airport boundary may have developed a

tolerance to odour emissions arising from airport operations, but this may not be

the case for those which will be located closer to the new DCO Project boundary,

such as receptors in Harmondsworth, Sipson and West Drayton.



7.10.167 Table 7.51 below summarises the results from the risk-based assessment of

odour during Phase 2 and Phase 3. The assessment is not a prediction of what

will actually occur during Phase 2 and Phase 3, but the potential for occurrences.

For operational activities in Phase 3, it is likely that odour effects will be similar to

those occurring in Phase 2. This is because, although ATMs continue to increase,

it is considered that the observable odour effects will be negligible as the locations

of emissions will be broadly similar.



Table 7.51: Operational odour risk-based assessment

Community Area Source Odour Potential

Percentage winds at low speeds (< 3m/s)

Distance of North West Runway to nearest receptor in community area (m)

Pathway Effectiveness

Risk of Odour Exposure

Receptor Sensitivity

Odour risk-based assessment results

Harmondsworth Medium 5.1% 174 High Medium High Moderate Adverse

West Drayton Medium 5.1% 874 Moderate Low High Slight Adverse

Sipson Medium 5.1% 247 High Medium High Moderate Adverse

Harlington Medium 4.9% 404 Moderate Low High Slight Adverse

Hayes Medium 4.9% 1834 Ineffective Negligible High Negligible

Cranford Cross Medium 4.9% 2112 Ineffective Negligible High Negligible

Cranford Medium 4.1% 3261 Ineffective Negligible High Negligible

Heston Medium 4.1% 4176 Ineffective Negligible High Negligible



Hounslow (West and Heath) Medium 1.8% 4248 Ineffective Negligible High Negligible

Feltham North Medium 2.1% 3604 Ineffective Negligible High Negligible

Bedfont Medium 2.1% 2985 Ineffective Negligible High Negligible

Stanwell Medium 2.6% 861 Moderate Low High Slight Adverse

Stanwell Moor Medium 2.6% 377 Moderate Low High Slight Adverse

Poyle Medium 4.1% 280 Moderate Low High Slight Adverse

Colnbrook Medium 5.7% 484 Moderate Low High Slight Adverse

Brands Hill Medium 5.7% 1304 Ineffective Negligible High Negligible

Iver and Richings Park Medium 5.1% 909 Moderate Low High Slight Adverse



7.10.168 It is possible that some local communities may experience occasional, short-term

odour annoyance under specific weather conditions. At present, a limited number

of complaints in relation to aviation fuel odour are currently received from

receptors in the vicinity of Heathrow (fewer than one complaint per month). It is

anticipated that, given the increase in activity and size of Heathrow and

introduction of activities closer to different communities, there may be occasional,

short-term increases in the level of annoyance. As a result, the number of odour

complaints received may increase. However, this is considered likely to remain at

a limited level due to the low frequency of the necessary meteorological conditions

and medium odour source potential. This effect is therefore considered to be not

significant. The procedure for raising complaints, and subsequent investigation of

these complaints will continue.

7.11 Preliminary assessment of significance

7.11.1 The significance of effects remaining once all embedded environmental measures

have been taken into consideration is summarised in Table 7.52.



Table 7.52: Summary of significance of adverse and beneficial effects

Receptor and effect Sensitivity

importance

or value

Magnitude of

change

Significance Summary rationale

Construction activities

Emission of dust causing loss

of amenity at sensitive

receptors (residential

properties, schools, medical

facilities, commercial sites,

businesses) near to work sites

and haul roads

High Negligible Not

significant

The good practice measures included in the draft CoCP will be

used to reduce emissions from construction activities and control

them where necessary so that effects are not significant.

Emission of odour causing





businesses) near to work sites

and haul roads

High Negligible Not

significant

The good practice measures included in the draft CoCP will be

used to reduce emissions from construction activity and control

them where necessary so that effects are not significant.

Construction/operational activities

Increased emission from

aircraft, airfield activities and

road traffic that could increase

concentrations of NO2, at

receptors (residential, schools,

medical facilities) where AQOs

apply

High Substantial

adverse

impacts at

worst in 2022

only.

Moderate

adverse

impacts at

worst in other

assessment

Not

significant

Exceedances of the annual mean NO2 AQO and substantial

adverse impacts at a small number of receptors are predicted

during the construction phase (c. 2022), however impacts will be

negligible at the majority of receptors (including those outside of

the Core AQO Assessment Area). No exceedances of the of the

NO2 annual mean AQO are predicted are predicted in other

assessment years. There are predicted to be increases in NO2

concentration of moderate adverse magnitude at a number of

receptors in these years, but impacts will remain negligible at the

majority of receptors.




importance

or value

Magnitude of

change


years.

Negligible

impacts at the

majority of

receptors.




concentrations of PM, at



apply at all receptors

High Negligible Not

significant

Overall effects are considered to be not significant as no

exceedances of the relevant AQOs are predicted, the majority of

receptors will experience negligible impacts and no moderate or

substantial adverse impacts are predicted in any assessment

year.




concentrations of SO2, at



apply at all receptors

High Negligible Not

significant

Overall effects are considered to be not significant as

concentrations are predicted to be well below the levels at which

the relevant AQOs would be exceeded.




concentrations of pollutants of

NO2 at locations where UK

compliance with EU limit

values is assessed (PCM

locations)

High Increases in

NO2

concentration

of up to

2.4µg/m3 at

PCM locations

Not

significant

Overall effects on NO2 concentrations at PCM locations are

considered to be not significant as the DCO Project will not:

a. result in a zone or agglomeration which is reported as

being compliant with the Ambient Air Quality Directive

(2008/50/EC) ('the Air Quality Directive') becoming non-

compliant; or

b. affect the ability of a non-compliant zone or

agglomeration to achieve compliance within the most

recent timescales reported to the European Commission.

Operational activities




importance

or value

Magnitude of

change


Increased emission of odour

from airfield activities causing





businesses)

High Occasional,

short-term

moderate

adverse

Not

significant

A limited number of complaints in relation to aviation fuel odour

are currently received from receptors in the vicinity of the Airport.

It is possible that some different local communities may

experience annoyance under specific weather conditions.

However, this will be occasional and short-term. Therefore, this

effect is considered to be not significant.



7.12 Assessment of cumulative effects

Introduction

7.12.1 The cumulative effects assessment (CEA) presented in this section reflects

Stage 3 in the CEA process set out in Section 5.8 of Chapter 5.

7.12.2 The assessment of cumulative air quality and odour effects is based on

professional judgement, taking into account the levels of significance identified in

the primary or ‘stand-alone’ assessment, and identifying whether effects could be

different when ‘other development’ is considered.

7.12.3 A CEA is only undertaken for those receptors that are likely to experience effects

greater than negligible in the primary assessment. This is because such effects

are unlikely to result in any discernible positive or negative effects on a receptor. It

is considered that they are extremely unlikely to result in a significant cumulative

effect, even if multiple effects of a similar significance are considered.

7.12.4 The following sections present the assessment of the cumulative effects of the

DCO Project and ‘other developments’ on air quality and odour. Effects are

described for each phase of the DCO Project where relevant.

7.12.5 The ‘other developments’ to be considered in the CEA for the PEIR are those on

the ‘assessment list’ provided in Section 5.8 of Chapter 5.

7.12.6 The CEA has considered the spatial area within which ‘other development’ could

be located, which, together with the DCO Project, could result in likely significant

effects on receptors. This is defined as the Zone of Influence (ZOI). Only those

developments in the assessment list that fall within the Air Quality and Odour ZOI

(which matches the Core AQO Assessment Area), Dust ZOI and Air Quality 5km

Major Emitters ZOI have the potential to result in cumulative effects with the

Project. The ZOIs are shown in Figure 5.1, Volume 2 and Figure 5.3, Volume 2.

All developments on the assessment list falling outside the ZOIs are excluded from

this assessment and are indicated in Table 7.54.

Emissions from road traffic

7.12.7 The HHASAM on which the dispersion modelling to predict pollutant

concentrations is based is inherently cumulative as it uses modelled traffic data

that has been adjusted to account for growth in future traffic flows. The modelling

takes account of employment and housing projections, some future infrastructure

projects and development in Development Plans and the planning process. No

additional cumulative assessment associated with emissions from road traffic has

therefore been undertaken.



7.12.8 The SAP document and HHASAM traffic data used are based on an ‘Assessment

Case’, which represents a future year where only transport improvements that are

committed (those that are funded and have all necessary consents in place) are

brought forward. This means that several planned large infrastructure schemes

that are considered likely to come forward, such as the Western and Southern Rail

Links promoted by the Department for Transport and Network Rail, but which are

not yet sufficiently certain, are not taken into account.

7.12.9 In testing the SAP Heathrow has also considered an 'Expected Case', to

determine the revised level of interventions that would be necessary if these

planned large infrastructure schemes are brought forward as currently anticipated.

The preliminary modelling presented in the SAP document demonstrates that

there is forecast to be a similar public transport mode share of Heathrow travel in

the Expected Case (55%) to the Assessment Case (57%). While this appears

potentially counter-intuitive, given that the Expected Case includes the Western

and Southern Rail links, which would be expected to boost public transport use, it

reflects the fact that the focus in preparing the SAP document has been on

developing a package of interventions that achieve the ANPS targets in the

Assessment Case. The overall package of interventions for the Expected Case is

currently less developed but could be refined to achieve similar or better outcomes

to the Assessment Case.

7.12.10 As such, in scenarios that include planned infrastructure schemes, such as the

Western and Southern Rail links, the forecast levels of airport-related demand by

mode would not be expected to materially differ from those on which this

assessment is based. However, it is recognised that the introduction of these

schemes would be likely to change mode choice and the geographic distribution of

demand by mode in the areas served by these schemes. It is also recognised that

such schemes have potential to exert a cumulative effect as a result of

construction activities, which may run concurrently with those carried out for the

DCO Project, should they receive consent as well as the DCO Project. Such

effects will be considered in the development of the CTMP and CWTP and they

will be considered in the assessment carried out for the ES.

7.12.11 The Western Rail Link would provide direct rail access to the Airport from areas to

the west, including Slough, Maidenhead and Reading, while the Southern Rail Link

would provide direct rail access to the Airport from areas to the south, including

Staines, Chertsey and Virginia Water. As these are all areas from which many

Heathrow colleagues currently drive to the Airport, in the Expected Case there

would likely be fewer car trips to the Airport from these areas.

7.12.12 It is considered that the inclusion of major infrastructure schemes, such as the

Western and Southern Rail Links, would reduce the use of and improve the

operation of the strategic road network around Heathrow.



7.12.13 Consequently, the information presented in this assessment, based on the

expected use and operation of the highway network with the DCO Project in the

Assessment Case is considered to be robust and it is considered that long-term

adverse cumulative effects are unlikely.

Emissions from other sources

7.12.14 Additional criteria specific to this chapter have been employed to further screen

developments in the assessment list. This has ensured that only developments of

a scale and nature that could result in likely significant cumulative effects related to

air quality and odour are included in the assessment. The air quality and odour

screening criteria are set out in Table 7.53.

7.12.15 This screening stage will also be applied to the ES CEA, in order to screen the

shortlist of developments and identify those that have the potential to result in

likely significant cumulative effects and therefore require assessment in the air

quality and odour chapter.

Table 7.53: Air quality, odour and dust CEA screening

CEA Zone of

Influence (ZOI)

Screening criteria Rationale

Air Quality and

Odour ZOI

With respect to air quality

effects, include all

development with the

exception of retail, office

and food establishment

developments.

Retail, office and food establishment developments are

unlikely to result in emissions to air and affect

concentrations in the Core AQO Assessment Area.

Furthermore, in accordance with guidance from

LAQM.TG(16), exceedances of the health based AQOs

should be assessed at outdoor locations where

members of the general public are regularly present over

the averaging time of the objective. In accordance with

the guidance, workplaces are excluded.

All other types of developments could either be sources

of air emissions, or result in receptors that could

experience air quality effects as a result of the DCO

Project.

Air Quality and

Odour ZOI

With respect to odour

effects, include all

development types

All new developments could be either receptors or

sources of odour emissions.

Air Quality

Major Emitters

ZOI

Include all mineral,

industrial or energy

developments

All mineral, industrial and energy developments within

5km of the Core AQO Assessment Area could

potentially affect air quality within it if they include activity

with an elevated stack/chimney.

Dust ZOI Include all development

types

All new developments could be sensitive to dust arising

from the DCO Project.



1.1.1 Following application of the CEA screening criteria, the following core and optional

developments on the assessment list in Section 5.8 of Chapter 5 brought forward

for assessment in the CEA are shown in Table 7.54.

Table 7.54: Developments brought forward for CEA

‘Assessment list’ developments from

Chapter 5, Section 5.8

Air Quality Air Quality

Major

Emitters

Dust Odour

O109 Land at Harmondsworth, Holloway Close x1

O591 Rectory Lane, Cranford Lane x1

O595 Stanwell Recycling, Stanwell Quarry x1

O596 Stanwell Recycling, Stanwell Quarry x1

O601 Queen Mary Reservoir and Land West of

Queen Mary Reservoir x1 x1 x1

O608 Cemex Datchet Quarry, Land at Riding

Court Farm x1 x1 x1

O609 Land East of Horton Road x1

O615 Southall Gas Works x1 x1

O732 Queen Mary Reservoir and Land West of

Queen Mary Reservoir x1 x1 x1

O745 Land at Milton Park Farm x1 x1 x1

O750 Land at Watersplash Farm x1 x1 x1

O751 Slough Heat & Power Station x1 x1 x1 x1

O810 M4 Junctions 3 to 12 Smart Motorway x2

O811 High Speed 2 (London - West Midlands) x1 x2 x1 x1

O812 Western Rail Link to Heathrow x1

O813 Southampton to London Pipeline Project x2

A2 T5+ (T5A) x1

A3 T5+ (T5B) x1

A4 T5+ (T5C) x1

A5 Perry Oaks Fuel Farm x1

Notes: 1 Development screened out as falls outside of the Air Quality and Odour ZOI, Air Quality 5km Major Emitters

ZOI or the Dust ZOI. 2 Development screened out as although falling in the Air Quality and Odour ZOI, Air Quality 5km Major

Emitters ZOI or the Dust ZOI, development does not meet screening criteria.



Phase 1: c. 2022-2026

7.12.16 None of the developments taken forward for assessment are considered likely to

result in emissions that would alter the conclusions with regard to NO2 and PM

detailed in Table 7.52. Development O615 Southall Gas Works would introduce

sensitive receptors, but negligible effects on pollutant concentrations as a result of

the DCO Project are forecast in this area. Development O591 Rectory Lane,

Cranford Lane would be considered as a sensitive receptor in relation to short-

term AQOs, but negligible effects as a result of the DCO Project are forecast in

relation to these.

7.12.17 None of the developments taken forward for assessment within the Air Quality

5km Major Emitters ZOI have been identified that could give rise to emissions that

could affect pollutant concentrations within the Core AQO Assessment Area.

7.12.18 It is assumed that the DCO Project and other developments will adopt best

practice management techniques to reduce dust emissions such that all individual

development effects will be negligible, and the cumulative effect will be negligible.

7.12.19 None of the taken forward for assessment have been identified with the potential

for odorous emissions that could exert a cumulative effect with the DCO Project.

Development O615 Southall Gas Works would introduce sensitive receptors, but

negligible effects in relation to odour as a result of the DCO Project are forecast in

this area. Development O591 Rectory Lane, Cranford Lane would be considered

as a sensitive receptor in relation to odorous emissions, but negligible effects as a

result of the DCO Project are forecast in this area.

7.12.20 There are therefore considered to be no cumulative effects as a result of other

developments in Phase 1, and the magnitude of change and significance reported

in Table 7.52 remain unchanged; all effects are not significant.

Phase 2: c. late 2026-2035

7.12.21 For construction dust and odour, given the peak construction activities for the DCO

Project occur during Phase 1, the assessment of cumulative effects in Phase 1 is

considered to be most representative of the likely significant cumulative effects of

the DCO Project and other developments are therefore not repeated here for this

PEIR assessment.

7.12.22 For operational emissions, including odour, the conclusions with regard to Phase

1, remain valid for Phase 2.






Phase 3: c. 2036-2050

7.12.24 For construction dust and odour, given the peak construction activities for the DCO

Project occur during Phase 1, the assessment of cumulative effects in Phase 1 is

considered to be most representative of the likely significant cumulative effects of

the DCO Project and other developments are therefore not repeated here for this

PEIR assessment.

7.12.25 For operational emissions, including odour, the conclusions with regard to Phase

1, remain valid for Phase 3.




7.13 Consideration of additional environmental measures and compensation

7.13.1 No additional environmental measures are proposed to further reduce air quality

and odour effects that are identified in this PEIR at this stage. The measures

detailed in Section 7.5 are shown in the assessment to be effective at managing

the effects of the DCO Project. The implementation of the measures detailed in

Section 7.5 will be secured through the Application and other documents (e.g. the

Surface Access Strategy to be prepared on the basis of the SAP document).

7.14 Next steps

Introduction

7.14.1 Further work that will be undertaken to support the air quality and odour

assessment and presented within the ES is set out below.

Baseline

7.14.2 Baseline monitoring data for 2018 will be collated and included in the ES. The

dispersion model verification will be updated to include the 2018 calendar year.

Assessment

7.14.3 Model input data, including road traffic data from HHASAM and aircraft schedules

will be refined, and the air quality assessment will be based on the final versions of

these models, inputs and assumptions. Assumptions regarding operational airside

activity will be refined on the basis of surveys carried out in 2019. Modelling

carried out for assessment years during the construction phase will reflect the



CTMP and CWTP. The impact of the HULEZ on pollutant concentrations will be

considered in the assessment.

7.14.4 The Core AQO Assessment Area will remain unchanged, but dispersion modelling

may be carried out for additional areas depending on the final road traffic datasets

and the likely changes in traffic flows on the road network outside of this Core

AQO Assessment Area.

7.14.5 Additional assessment years will be considered, in order to ensure the full range of

potential impacts are quantitatively considered, particularly in the period from 2022

to 2030.

7.14.6 Dispersion modelling will use the latest version of Defra’s background maps

available at the time.

7.14.7 The assessment of compliance with EU limit values will be based on the latest

version of Defra’s projections at PCM locations available at the time. Where

demand modelling does not show that there will be reductions in traffic flows, and

where changes in traffic flows have the potential to lead to non-negligible changes

in air quality, dispersion modelling of discrete PCM road links will be undertaken to

assess the likely impact on limit value compliance.

7.14.8 The construction dust risk assessment will be updated to reflect the final phasing

of infrastructure and construction methodology proposed.

7.14.9 The cumulative effect of other schemes that would also be expected to affect air

quality, such as the Lakeside Waste Management Facility and the Western Rail

Link to Heathrow will be considered.

Engagement

7.14.10 Further technical engagement that will be undertaken to inform the air quality and

odour assessment presented within the ES. Ongoing engagement will be carried

out with the HSPG, TfL, Highways England and Natural England.

Date post:	24-Feb-2020
Category:	Documents
Upload:	others
View:	34 times
Download:	4 times

PRELIMINARY ENVIRONMENTAL INFORMATION REPORT · 7.5 Embedded environmental measures 7.29 7.6...

Documents