Appendix D

VARIATIONS CONSIDERED: AOS FOR AIRPORTS NPS

June 2018

TABLE OF CONTENTS

1 VARIATIONS TO SCHEMES ...... 3

1.1 BACKGROUND ...... 3

1.2 SCREENING ASSESSMENT METHODOLOGY ...... 4

2 STATEMENT OF PRINCIPLES VARIATIONS ...... 5

2.1 LGW-2R VARIATIONS ...... 5

2.2 LHR-ENR VARIATIONS ...... 6

2.3 LHR-NWR VARIATIONS ...... 15

3 VARIATION SCREENING AND ASSESSMENT RESULTS ...... 16

3.1 LGW-2R VARIATION: PHASING ARRANGEMENTS ...... 16

3.2 LHR- ENR VARIATION: ITERATION 3 ...... 16

3.3 LHR- ENR VARIATION: ITERATION 4 ...... 22

3.4 LHR-NWR VARIATION: M4 ...... 27

4 VARIATIONS SCREENING ASSESSMENT TABLES ...... 28

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TABLES

TABLE 1 LHR-ENR SURFACE ACCESS STRATEGY ASSESSED BY THE AIRPORTS COMMISSION ...... 6 TABLE 2 LHR-ENR RELATED SURFACE ACCESS STRATEGY ...... 7 TABLE 3 LHR-NWR SOP SURFACE ACCESS STRATEGY...... 15 TABLE 4 SOP VARIATION ELEMENTS ...... 28 TABLE 5 LGW-2R VARIATION SCREENING ASSESSMENT: PHASING ...... 29 TABLE 6 LHR-ENR VARIATION SCREENING ASSESSMENT: ITERATION 3 ...... 42 TABLE 7 LHR-ENR VARIATION SCREENING ASSESSMENT: ITERATION 4 ...... 56 TABLE 8 LHR-NWR VARIATION SCREENING ASSESSMENT: M4 WIDENING ...... 67

FIGURES

FIGURE 1 LHR-ENR ASSESSED BY THE AIRPORTS COMMISSION ...... 12 FIGURE 2 LHR-ENR ITERATION 3 ...... 13 FIGURE 3 LHR-ENR ITERATION 4 ...... 14

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1 VARIATIONS TO SCHEMES

1.1 BACKGROUND

1.1.1 The three schemes which are considered within this Appraisal of Sustainability (AoS) are those assessed by the Airport Commission. The shortlisted scheme promoters continued to refine their schemes following the formal submission of scheme designs in May 2014 to the Airports Commission (AC).

1.1.2 The three schemes remain fundamentally the same as those assessed by the AC in most respects. However, further variations to the scheme designs were captured by Government and the scheme promoters in the form of a Statement of Principles (SoP) for each scheme1. These SoP set out the scheme proposed by the promoters including the variations to the scheme design originally assessed by the AC which are presented within the AoS. The SoPs set out the proposed schemes which have been considered prior to the publication of the National Policy Statement.

1.1.3 The variations set out within the SoPs have been subject to a high-level screening as part of the AoS. This screening has been undertaken to determine whether the variations result in differences to the original AC schemes which could give rise to a change in the significance of environmental or sustainability effects which are reported in the AoS. The principal changes to scheme design as described in the SoPs comprise:

 London Gatwick Second Runway (LGW-2R): Change in phasing of construction; the first phase of the new terminal would open at the same time as the new runway in 2025;  London Heathrow Extended Northern Runway (LHR-ENR): The M4 would not require widening to cope with the increased demand resulting from expansion; surface access proposals

1 The Secretary of State for Transport and Gatwick Airport Limited, 2016. Statement of Principles 1 The Secretary of State for Transport and Heathrow Hub Limited and Runway Innovations Limited, 2016. Statement of Principles 1 The Secretary of State for Transport and Heathrow Airport Limited, 2016. Statement of Principles

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comprising M25 works and tunnelling on a like for like replacement basis (J14 to the south and J15 to the north); local road diversions and improvements including for the A4 and A3044; and  London Heathrow North West Runway (LHR-NWR): The M4 would not require widening to cope with the increased demand resulting from expansion.

1.1.4 The variations to the scheme are described in Section 2 below.

1.2 SCREENING ASSESSMENT METHODOLOGY

1.2.1 A screening process was used to determine whether, based on the existing evidence, there is likely to be a change for each AoS topic. This uses the Appraisal Framework comprising objectives and appraisal questions as presented in Section 4 of the AoS Report. It considers the following:

 the assessment of the proposal as submitted to the AC;  the likely change to the assessment;  whether the change is likely to change the assessment of significance;  where the assessment of significance is likely to change, where further assessment is required; and  any uncertainties, assumptions or limitations of the existing information on the variation.

1.2.2 The screening assessment was undertaken using publically available sources of mapping, such as MAGIC2, to identify environmental constraints.

1.2.3 The results of the Screening Assessment are reported in Tables 4 to 7.

1.2.4 Subsequent to the screening assessment, this assessment considers AoS objectives and questions where potential changes in the significance of effects were identified. The results of this assessment are reported in Section 3. In addition, the assessment provides a more detailed review of the screening assessment conclusions, where additional impacts are anticipated, but these do not result in a change to significance.

2 Department for Farming and Rural Affairs, 2016. Magic. [online] Accessed 10/10/2016

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2 STATEMENT OF PRINCIPLES VARIATIONS 2.1 LGW-2R VARIATIONS

2.1.1 The LGW-2R SoP describes the proposed phasing arrangements for construction of airport expansion at Gatwick. The phasing arrangements described are summarised below. The SoP sets out when passenger capacity will be delivered, and when airport facilities and surface access systems will be constructed to deliver the necessary increase capacity at each phase.

PHASE 1 (OPEN IN 2025)  Second runway which will be built to its full paved length of 3,400m;  Capacity of the two-runway Airport initially to 63mppa (millions of passengers per annum), which is expected to be reached by 2029;  First phase of the new terminal would open;  A23 re-routed along the southern boundary of the extended Airport and then parallel with the railway where it will connect (temporarily) back into the existing roadway which passes beneath South Terminal;  Balcombe Road will be diverted maintaining a through-route for local traffic passing around the eastern boundary of the Airport;  A short section of Ifield Road will be diverted around the southwest corner of the Airport;  New dual carriageway road access connecting the M23 (Junction 9) and the new terminal;  Further capacity improvements will be made to the junctions serving North and South Terminals as well as Longbridge Roundabout (the junction of the A23 and A217) located to the north of the Airport; and  The first phase will also include land outside the Airport boundary required for landscape and habitat management which will form part of the mitigation measures designed to off-set the environmental impacts of expansion.

PHASE 2 (OPEN IN 2030)  Capacity to 73mppa;  Further improvements to airport terminals and facilities within the airport site; and  Completion of full A23 diversion to east of railway.

PHASE 3 (OPEN IN 2035)  Capacity to 82mppa; and  Further improvements to airport terminals and facilities within the airport site.

PHASE 4 (OPEN IN 2040)  Capacity to 95mppa; and  Further improvements to airport terminals and facilities within the airport site.

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2.1.2 The phasing arrangements for LGW-2R do not change the completed facilities or surface access systems which would be provided in support of airport expansion, only the timing of at which these are delivered.

2.2 LHR-ENR VARIATIONS

2.2.1 The AC carried out its assessment of LHR-ENR on the basis of the same ‘on-site’ Surface Access Strategy as LHR-NWR (Table 1 below). For the rail network, an identical surface access strategy is proposed to that for LHR-NWR. The road interventions vary slightly between the two schemes, as the footprint of LHR-ENR requires a different strategy for improvements to the local road network, as although similar roads are affected, they are in a different location.

Table 1 LHR-ENR Surface Access Strategy Assessed by the Airports Commission3

Category Location Description of Surface Access Arrangements

Strategic Road M4 J3 to J4 Road widening

M4 Airport Spur Road widening

M4 J2 to J3 Road widening

M4 J4 and J4B Road widening

M4 Large M4 Junction 4b replacement

M4 Higher capacity at M4 Junction 4a

M4 Capacity improvements to existing main airport tunnel

M25 M25 tunnelling (south of Junction 15)

Local Road M25 J13 (A13) D2 Grade-separated junction and flyover/bridge structures Network Tunnel From A4 to T5

A4 Access Tunnel running parallel to M25 – expected to have light traffic

New roundabouts on access Southern Road Tunnel/Southern Perimeter Road roads Interchange

Airport Roads New link from Junction 13

Heathrow Road Tunnel Providing new spur access

Airport One Way One way system for western campus

Rail Southern Rail Access to Staines

3 Airports Commission, 2015. Final report, p. 159. [online] Accessed 05/01/2016.

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2.2.2 The LHR-ENR Surface Access Strategy which was assessed by the AC has undergone further review by the promoter to address potential air quality impacts. Variations proposed to the Department for Transport (DfT) and described within the SoP include iterations (see Figures 1 and 2) which are considered by the promoter to be deliverable, and could provide reductions in adverse air quality impacts relative to the surface access proposals assessed by the AC and described in Table 1 above.

2.2.3 Table 2 describes the LHR-ENR surface access arrangements considered by the AC assessment, and also Iterations proposed by the promoter.

Table 2 LHR-ENR Related Surface Access Strategy4 Category Location Description of Surface Access Strategy AC’s LHR-ENR SoP Variation Iteration 3 SoP Variation Iteration 4 Strategic M4 J3 to J4 Road widening Road M4 Airport Spur Road widening M4 J2 to J3 Road widening M4 J4 and J4B Road widening M4 Large M4 Junction 4b replacement M4 Higher capacity at M4 Junction 4a M4 Capacity improvements to existing main airport tunnel M25 M25 tunnelling (south of Junction 15) M25 N/A M25 Junction 14 connection to Terminal 5/6 Access Local A4 Diversion to N/A Diversion of the A4 north N/A Road M4 Spur west of Harmondsworth Network Diversion of the A4 east Sipson Existing A4 downgraded to single carriageway west of M4 Spur and stopped up at BA Waterside Traffic N/A N/A Traffic management Management on along line of existing A4, Existing A4 between A3044 and M4 Spur junction at Terminal 2 A4 to Southern A3044 diverted through A4/ A3044 access to Southern Perimeter Road Perimeter Road tunnel running parallel to reconfigured to accommodate M25 Junction 14 link connection via M25 – expected to have A3044 Diversion light traffic New Southern Road Tunnel/ Southern Perimeter Road Interchange junction roundabouts on Southern Perimeter Road configuration altered to accommodate M25 Junction access roads Interchange junction at 14 link Terminal 5/6 Southern Road Tunnel under southern runway unaffected. Airport Roads A3044 diverted to link New M25 Junction 14 connection to Terminal 5/6 Terminal 5/6 with M25 J13

4 Airports Commission, 2015. Final report, p. 159. [online] Accessed 05/01/2016.

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M25 J13 D2 Grade-separated junction New M25 Junction 14 connection to Terminal 5/6 and flyover/bridge structures Heathrow Road Providing new spur access Tunnel Airport One Way One way system for western campus Rail Southern Rail Access to Staines

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2.2.4 The primary differences between the surface access arrangements are set out below:

 AC’s Extended Northern Runway Surface Access strategy (see Figure 1):

 Terminal 5/6 connected to M25 Junction 13 via diversion of the A3044;

 No improvements on the A4 west of Stanwell Moor Road;

 Traffic congestion disbenefits of these arrangements; and

 Congestion on the A4 and connecting roads.  Iteration 3 (see Figure 2):

 M25 Junction 14, providing connection between M25 and Terminal 5/6 via A3044 south west of the airport;

 A4 diverted north and west of Harmondsworth and north and east of Sipson. The diversion will be partly online, and partly offline and will provide a direct connection between the A4 at A3044 Stanwell Moor Road and the M4 at Junction 4;

 Existing A4 downgraded to single carriageway west of M4 Spur and stopped up at BA Waterside; and

 Potential traffic congestion benefits of Iteration 3 Surface Access relative to the AC’s surface access arrangements: . Traffic moving east via the A4 would be directed north via the A4 diversion, the existing A4 would be stopped up at BA waterside. This would reduce congestion caused by both airport users and through traffic using the A4; . Traffic accessing Terminal 5 and A3044 Stanwell Moor Road from the east via the M4 Junction 4 would travel via the A4 diversion, instead of using the M4 Spur and the current A4 alignment. This would reduce congestion caused by airport users on the A4; . Reduced congestion on the A4 would reduce congestion on connecting roads; and . Traffic accessing Terminal 5/6 via travelling north or south via the M25 will travel via improved M25 Junction 14, and A3044 diversion. This will reduce congestion on the M25 at Junction 13.  Iteration 4 (see Figure 3):

 M25 Junction 14 connection M25 and Terminal 5/6 south west of the airport;

 Traffic management on the A4 west of Stanwell Road connecting to M4 Spur;

 Potential traffic congestion benefits of Iteration 3 Surface Access relative to the AC’s surface access arrangements: . Traffic moving between the A3044 Stanwell Road Junction and the M4 Spur would be subject to traffic management. This would reduce congestion caused by airport users and through traffic using the A4; . Reduced congestion on the A4 would reduce congestion on connecting roads; and . Traffic accessing Terminal 5/6 via travelling north or south via the M25 will travel via improved M25 J14, and A3044 diversion. This will reduce congestion on the M25 at J13.

2.2.5 Iteration 3 and Iteration 4 would both reduce congestion on the A4 when compared to the AC’s Extended Northern Runway Surface Access proposals.

AIR QUALITY AND ENR VARIATIONS

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2.2.6 Under the EU Ambient Air Quality Directive, the UK Government has a legal obligation to achieve air quality limit values. A key aspect of the AC’s air quality assessment, and subsequently the AoS, was consideration of the likely impact of the schemes on the UK’s compliance with the EU limit values.

2.2.7 The UK Government assesses compliance with EU limit values using a combination of monitoring and modelling with the Pollution Climate Mapping (PCM) model. The UK is divided into 43 zones and agglomerations for reporting purposes. A zone or agglomeration is defined as being compliant when the maximum monitored or modelled concentration within that zone or agglomeration is less than or equal to the limit value.

2.2.8 The PCM model is used to estimate pollutant concentrations at background and roadside locations throughout the UK. Background concentrations are modelled on a 1km grid covering the entire UK; roadside concentrations are modelled for locations adjacent to approximately 9000 roads (A-roads and motorways) across the UK.

2.2.9 In December 2015, the Government published an Air Quality Plan (the 2015 Plan) and associated evidence base; this was updated in July 2017 (the 2017 Plan). Alongside the AoS, WSP | Parsons Brinckerhoff was requested to undertake a re-analysis of the AC’s modelling and EU limit value compliance assessment taking into account the publication of the 2015 Plan. Additional work has been undertaken by WSP to assess the implications of the 2017 Plan and PCM modelling, on the conclusions of the AC’s air quality assessment in relation to EU Directive limit value compliance5,6,7. A principal conclusion of the WSP | Parsons Brinckerhoff re-analysis study was that LHR-ENR, as assessed by the AC (without surface access variations), was likely to delay the compliance of the Greater London Urban Area Agglomeration with EU limit values.

2.2.10 This was due in part to the combined impact of on-airport emission sources and road traffic on the A4 to the west of the M4 spur (Bath Road) on annual mean nitrogen dioxide concentrations, but also to impacts on major arterial roads into central London from the west (A40). The impact of on- airport emission sources near Bath Road is inherent to the particular design of LHR-ENR, with an increase in activity relatively close to the existing northern boundary of the airport. In addition, road traffic on the A4, which runs parallel to the northern runway under the AC’s surface access strategy for LHR-ENR is subject to long term growth in non-airport related traffic but also increases with the option since it is the primary route through which traffic arriving from London via the M4 would access Terminal 5 and 6. However, in this area, it is the impact of airside emissions rather than road transport that dominates and the risk of exceedance of EU limit values with LHR-ENR is, therefore, strongly influenced by the localised impact of on-airport sources.

2.2.11 The WSP Updated Re-analysis Study and the AC’s report also identified that whilst the modelled increases on arterial roads into central London with the airport are small in magnitude, they have the potential to affect the compliance with EU limit values. On these roads, the impact of airside emissions was imperceptible, and the impact of the schemes was solely related to road traffic.

2.2.12 The significant risk of an impact on compliance with EU limit values was a key constraint to the surface access strategy for LHR-ENR as assessed by the AC, and a reason why LHR-ENR performed relatively poorly compared to the LHR-NWR scheme on air quality.

2.2.13 With LHR-NWR, the majority of the traffic on the existing A4 is rerouted to the north (closer to the M4 and along the existing A3044) and the existing A4 (on a section of Bath Road) is used only for access to local businesses. As such, the potential for the coincidence of significant impacts from airport sources (due to proximity to airside activity) and busy roads (the A4) is reduced in comparison to LHR-ENR.

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2.2.14 Iterations 3 and 4 of the Surface Access Strategy for LHR-ENR seek to replicate the performance of the LHR-NWR surface access arrangements for air quality effects. They are considered qualitatively in this Appendix.

5 WSP | Parsons Brinckerhoff, 2016, Air Quality Re-analysis, impact of new pollution climate mapping projection and national air quality plan. [online] Accessed 01/12/2016 6 WSP | Parsons Brinckerhoff, February 2017, Updated Air Quality Re-Analysis, published as part of the draft Airports NPS Consultation documentation) 7 WSP, October 2017, 2017 Plan Update to Air Quality Re-Analysis

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Figure 1 LHR-ENR Assessed by the Airports Commission

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Figure 2 LHR-ENR Iteration 3

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Figure 3 LHR-ENR Iteration 4

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2.3 LHR-NWR VARIATIONS

2.3.1 The SoP for LHR-NWR sets out the Surface Access Strategy for airport expansion. For example, the road and rail improvements which were included in the surface access strategy for the LHR- NWR included tunnelling a section of the M25 to the west of the airport.

2.3.2 The specific proposed improvements to the M4 which were assessed by the AC are not considered to be a necessary improvement solely to support airport expansion within the SoP. Future improvements to the M4 will be considered as part of the Government’s future investment planning process and would be developed and delivered independently of airport expansion.

2.3.3 The revised road and rail options, which are considered necessary specifically to support airport expansion, are set out in Table 2.4 below.

Table 3 LHR-NWR SoP Surface Access Strategy

CATEGORY LOCATION DESCRIPTION OF AC’S DESCRIPTION OF LHR-NWR SOP SURFACE ACCESS STRATEGY SURFACE ACCESS STRATEGY

Strategic M4 J3 to J4 Road widening Not considered to be a necessary Road improvement within the SoP solely to M4 Airport Spur Road widening support airport expansion. M4 J2 to J3 Road widening M4 J4 and J4B Road widening M4 Large M4 Junction 4b replacement M4 Higher capacity at M4 Junction 4a M4 Capacity improvements to existing main airport tunnel M25 M25 tunnelling (south of No Change Junction 15) Local A4 Diversion of A4 road No Change Road alignment, dual carriageway Network A3044 Diversion of A3044 road No Change alignment, dual carriageway Airport Roads Airport Way/Southern No Change Perimeter Road Interchange, grade-separated junction and flyover/bridge structures Heathrow Road Southern Road No Change Tunnel Tunnel/Southern Perimeter Road Interchange Airport One Way One way system for western No Change campus Rail Southern Rail [ No Change Access to Staines

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3 VARIATION SCREENING AND ASSESSMENT RESULTS 3.1 LGW-2R VARIATION: PHASING ARRANGEMENTS

3.1.1 The LGW-2R SoP sets out variations to airport expansion relating to the timing of construction, and provides additional detail to the diversion and arrangements for different phases.

3.1.2 The results of the Screening Assessment are reported in Table 4.

3.1.3 The Screening Assessment determined that the SoP Variation will not result in an increase or decrease in impacts which would change the significance of impacts reported within the AoS as assessed against the Appraisal Questions or Objectives.

3.1.4 No further assessment subsequent to screening was required for this scheme.

3.2 LHR- ENR VARIATION: ITERATION 3

3.2.1 The summary of the screening and assessment results for each Appraisal Objective and Appraisal Question are presented below. This follows and supports the screening assessment which is presented in Table 5.

3.2.2 The Screening Assessment concluded that the Iteration 3 variation may result in a change in the significance of effects for the AoS Appraisal Objectives and Questions relating to air quality. Further information relating to this change is presented below.

3.2.3 The Screening Assessment identified potential increases and decreases in impacts associated with development in or near areas which are sensitive for environmental or sustainability reasons (for example designated sites or residential properties). In addition to potential benefits for the air quality objectives, increases or decreases in sustainability impacts are presented for other questions and objectives. However, for other topics this was not sufficient for the overall significance of impacts assessed in the AoS to change. This is because due to the scale of the infrastructure proposed, smaller changes to the magnitude or other impact characteristics are not sufficient to change whether the impact has been assessed as significant or not. The results of the screening process and assessment are presented below.

Objective 1: To avoid or minimise negative effects on community viability, including housing, facilities and indirect effects

3.2.4 The A4 diversion could increase loss of community facilities including Heathrow Special Needs Centre and potential loss of land at the Little Brook Nursery. Housing in Harmondsworth and Sipson would be within 100m of the A4 diversion, but would not be affected by land take.

3.2.5 No increase in demand for housing and community facilities is anticipated.

3.2.6 The A4 diversion would result in mixed positive and negative impacts on community viability:  Improved traffic movements, and reduced journey times;  The A4 diversion has the potential to increase severance and lead to a reduction in the quality of amenity, particularly around Harmondsworth;  Reduced congestion, and a shorter delay to compliance with Air Quality Directive Limit Values in the Greater London Urban Area; and

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 The diversion of the A4 will create a new source of noise for residents in Harmondsworth and Sipson; overall noise effects associated with the A4 diversion are not expected to result in a material increase.

3.2.7 No changes to the overall significance of impacts reported within the AoS are expected.

Objective 2: To avoid or minimise disproportionate impacts on any social group.

3.2.8 Iteration 3 would result in mixed effects on social groups:

 Improved traffic movements, and reduced journey times;  Reduced congestion, and a shorter delay to compliance with Air Quality Directive Limit Values in the Greater London Urban Area;  Causes loss of community facilities including Heathrow Special Needs Centre and potential loss of land at the Little Brook Nursery, this would potentially increase effects on disabled people and children;  The A4 diversion has the potential to increase severance and lead to a reduction in the quality of amenity, particularly around Harmondsworth; and  The diversion of the A4 will create a new source of noise for communities residing in Harmondsworth and Sipson. Overall noise associated with the A4 diversion and alterations to the M25 at Junction 14 and A3044 connection to Terminal 5/6 are not expected to result in an increase in noise impacts.

3.2.9 No changes to the significance of impacts reported within the AoS are expected.

Objective 3: To maintain and where possible improve the Quality of Life (QoL) for local residents and the wider population

3.2.10 Iteration 3 would result in mixed effects on quality of life:

 The variation has the potential to improve the resilience of the surface access systems, improving quality of life;  The A4 diversion would lead to an increase in severance during operation and disruption for road users during construction;  The A4 diversion would potentially cause loss of community facilities including Heathrow Special Needs Centre and potential loss of land at the Little Brook Nursery. Additional housing in Harmondsworth and Sipson would be within 100m of the A4 diversion, but would not be affected by land take;  The variation would not result in any change to operational employment. The diversion of the A4 to a small increase in overall construction employment compared to the AC’s surface access arrangements;  Would not increase noise effects assessed, as aviation would be the main source of noise;  Has the potential to reduce congestion, particularly where a delay in compliance with EU Limit Values has been identified to the north of Heathrow in the AC’s surface access arrangements;  The diversion of the A4 north of Harmondsworth would cross areas which are designated as being sensitive for nature conservation and cultural heritage reasons, including the Colne Valley Park west of Harmondsworth, and the site of Harmondsworth Priory Cell. This would increase the detrimental effects on nature and conservation, and reduce quality of life; and  Although there are changes to some of the flood zones affected, the variation is not expected to result in a change to flood risk which would affect quality of life.

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3.2.11 No changes to the significance of impacts reported within the AoS are expected.

Objective 4: To maximise economic benefits and to support the competitiveness of the UK economy

3.2.12 No changes to the significance of impacts reported within the AoS are expected.

Objective 5: To promote employment and economic growth in the local area and surrounding region

3.2.13 The diversion of the A4, alterations to the M25 at Junction 14 and A3044 connection to Terminal 5/6 would improve the functioning of the surface access arrangements in the short term. However, similarly to the AC’s surface access arrangements the benefits to accessibility are expected to be negated by long term increases in transport demand for surface transport systems, including the road network. Further enhancements to the surface network may be required to ensure accessibility benefits are maintained in the long term.

3.2.14 There is potential for the diversion of the A4 to contribute to the growth of the local economy in the surrounding area, including potential for a small increase in overall construction employment compared the AC’s surface access arrangements for LHR-ENR.

Objective 6: To minimise and where possible reduce Noise impacts on human receptors

3.2.15 While variations to surface access transportation have the potential to change road traffic noise, any such effects would be localised and limited in spatial extent. Although the AoS considers noise from surface access, it is acknowledged that aviation noise is the predominant source of impact and therefore no changes to the significance of impacts reported within the AoS are expected.

Objective 7: To protect and enhance designated sites for nature conservation

3.2.16 The following potential impacts on internationally, nationally and locally designated sites are anticipated:

 The alterations to the M25 at Junction 14 is expected to increase direct effects, primarily due to land lost from the Staines Moor Site Special Scientific Interest (and therefore the South West (London Waterbodies Special Protection Area (SWLW SPA)) when compared to the AC’s surface access arrangements for LHR-ENR; and  The A4 diversion is likely to result in increased direct effects on a locally designated site, as it involves the loss of part of the Harmondsworth Moor (Hillingdon) Site Importance Nature Conservation.

3.2.17 No changes to the significance of impacts reported within the AoS are expected.

Objective 8: To conserve and enhance undesignated habitats8, species, valuable ecological networks and ecosystem functionality

3.2.18 The following potential impacts on undesignated habitats, internationally and nationally protect species and valuable ecological networks are anticipated:

 The A4 diversion likely to cause increased loss of priority deciduous woodland and traditional orchards habitat to the west of Harmondsworth;

8 Undesignated habitats are not covered by a nature conservation designation listed in Objective 7.

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 The A4 diversion would require a new crossing above the Colne River; and  A shorter diversion of the A3044 to connect the M25 Junction 14 would be required, and would reduce the requirement for new crossings or culverting of the Wraysbury River.

3.2.19 The variation has the potential to increase the effects on priority habitats from these sources, but would not change the outcome of the assessment.

3.2.20 No changes to the significance of impacts reported within the AoS are expected.

Objective 9: To protect sites designated for geodiversity

3.2.21 No changes to the significance of impacts reported within the AoS are expected.

Objective 10: To minimise loss of undeveloped soils and of Best and Most Versatile agricultural land, and protect soil against erosion, contamination and degradation

3.2.22 There would be an increase in land take around M25 Junction 14, and associated with the diversion of the A4. There would also be a decrease in land take associated with the A3044 diversion to Junction 13 (which would not be required under this variation). Overall there would be an increase in land take and loss of agricultural land. The areas affected by increased land take may include areas of Best and Most Versatile agricultural land.

3.2.23 No changes to the significance of impacts reported within the AoS are expected.

Objective 11: To protect the quality of surface and groundwaters, and use water resources sustainably

3.2.24 Iteration 3 would potentially result in changes to the quantity of watercourses to be culverted, effecting hydromorphology and the quality of surface watercourses. These effects include:

 The A4 diversion would increase the requirement for culverting of watercourses connecting the Colne River west of Harmondsworth; and  The alterations to the M25 at Junction 14 and A3044 connection to Terminal 5/6 would remove the need for the diversion of the A3044 to run parallel with the M25 south west of the Airport, as considered with the AC's surface access arrangements for LHR-ENR. This would decrease the requirement for culverting in the area adjacent to the Wraysbury River.

3.2.25 No changes to the significance of impacts reported within the AoS are expected.

Objective 12: To minimise flood risk and ensure resilience to climate change

3.2.26 The variation involves diversion of the A4 across the Colne River, and would require new development within Flood Zone 2 and 3. Overall there will be a reduction in development within Flood Zone 2 and 3, as the A3044 diversion to connect with the M25 Junction 13, which travels through the Wraysbury River floodplain would not be required.

3.2.27 No changes to the significance of impacts reported within the AoS are expected.

Objective 13: To improve air quality and reduce emissions consistent with EU, national and local standards and requirements.

3.2.28 Compliance with EU directives is assessed by UK Government alongside roads included in the PCM model.

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3.2.29 Flows on the existing A4 will be significantly reduced whilst flows on the route of the A4 diversion will increase. Indeed, with the A4 stopped up at BA Waterside, the PCM link from the M4 spur to the Colnbrook By-pass will no longer exist in its current form or will at least have significantly reduced flows such that it is unlikely to be considered to be ‘at risk’ of exceeding the EU limit value.

3.2.30 It is not possible to determine whether the A4 diversion would be included in future PCM modelling at all, but in any case, it is likely that total flows on the diversion will be lower than those modelled in the AC’s assessment for the A4 without restriction. Some traffic will still need to access the existing premises along the A4 but this will be lower than modelled by the AC. Furthermore, the route of the diverted A4 is further from the airport emission sources than the existing A4 and, therefore, the maximum impact alongside the diverted A4 is likely to be lower than that modelled by the AC which occurred at a location in proximity to high airside emissions and a busy road. As such, the scheme is likely to significantly reduce the risk of LHR-ENR impacting on compliance with limit values in the vicinity of the airport. In 2030, with the Government’s 2017 Plan, LHR-ENR with the scheme does not impact on compliance with EU limit values. The scheme will not, however, remove all risk of impacts on compliance with limit values alongside individual links since the risk of impacts on links in Central London will be unaffected by the changes in the vicinity of the airport.

3.2.31 The existing A3113, running eastwards from Junction 14 of the M25 to the airport Southern Perimeter Road, is currently included within the PCM model. The PCM modelling shows existing exceedances of the EU limit value on this link, although the PCM projections from the 2017 Plan (both baseline and with measures scenarios)9 showed a rapid decrease in concentrations over time. Notwithstanding this, Iteration 3 reintroduces access to the airport from Junction 14 of the M25 and flows on this route are likely to increase with airport expansion, albeit along a revised alignment. If the realigned A3113 from the M25 to the airport is included in future PCM modelling, then there is a risk that LHR-ENR could impact on compliance with EU limit values alongside the link. This risk did not exist in the AC’s assessment since Junction 14 of the M25 was removed.

3.2.32 Therefore, whilst the risk of impacts to compliance with EU limit values would be reduced in the vicinity of the airport by Iteration 3, LHR-ENR would remain at risk of worsening exceedances alongside individual roads in Central London even with this surface access strategy. As such, the significance of the effect is unlikely to change.

3.2.33 Iteration 3 would not affect UK Air Quality Objective Compliance. In addition, it is not likely to introduce exceedances of the UK’s air quality objectives for the protection of human health. Indeed, since maximum impacts with the scheme occurred to the north of the runway under the AC’s surface access strategy, maximum impacts might decrease slightly since the traffic component of the impact at this location would be reduced with Iteration 3.

Objective 14: To minimise carbon emissions in airport construction and operation

3.2.34 The variation is not expected to change the significance of carbon emissions from the AC’s surface access arrangements.

9 In the reanalysis the PCM datasets comprise:  2017 Plan PCM Baseline – PCM data, generated from a 2015 base year, based on COPERT v5 emissions factors and the measures identified in the UK’s 2015 Air Quality Plan  2017 Plan PCM With Clean Air Zones –2017 Plan PCM data, based on COPERT v5 emissions factors and taking into account the CAZ identified in the UK’s 2017 Plan WSP, October 2017, 2017 Plan Update to Air Quality Re-analysis, published as part of the revised draft Airports NPS Consultation documentation.

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Objective 15: To minimise consumption of natural, particularly virgin non-renewable, resources.

3.2.35 The diversion of the A4 would increase the volumetric consumption of construction materials required.

3.2.36 No changes to the significance of impacts reported within the AoS are expected.

Objective 16: To minimise the generation of waste in accordance with the principles of the Resource Efficiency Hierarchy.

3.2.37 The variation would not increase the volume of waste generated.

3.2.38 No changes to the significance of impacts reported within the AoS are expected.

Objective 17: Conserve and where appropriate enhance heritage assets and the wider historic environment including buildings, structures, landscapes, townscapes and archaeological remains

3.2.39 The following potential effects on designated and non-designated heritage assets are anticipated:

 The diversion of the A4 could affect the setting of Grade I, II* and a number of Grade II listed buildings. In particular, these include a Grade I Listed Tithe Barn north west of Harmondsworth (The Great Barn), and a Grade II* Listed Church (The Church of St. Mary);  East of Sipson, an offline section of the diversion of the A4 re-joins the current A408 adjacent to Sipson House, a Grade II Listed Building;  The setting of Harmondsworth Conservation Area has the potential to be affected by the diversion of the A4 to travel 200m north of the Conservation Area;  Two Archaeological Priority Areas are located north and west of Harmondsworth and also surrounding Sipson, and would be crossed by the A4 diversion. The Archaeological Priority Area west of Harmondsworth includes the site of a former Benedictine Priory;  There are Listed Buildings on the periphery of Stanwell Moor which may have views of the current A3113 and M25. The arrangement of the M25 Junction 14 and A3044 connection to Terminal 5/6 are not expected to generate an increase in effects relative to the AC’s surface access arrangements;  Data collection for non-designated heritage assets has not been undertaken, but there are likely to be increased effects on non-designated assets;  The A4 diversion is expected to generate an increase in noise, pollution and visual intrusion on heritage assets relative to the AC’s surface access arrangements;  The alterations to the M25 at Junction 14 and A3044 connection to Terminal 5/6 are unlikely to change noise, pollution and visual intrusion on heritage assets relative to the AC’s surface access arrangements; and  The variation would increase the number of heritage assets affected, including an additional effect on below ground archaeological remains associated with Harmondsworth Priory, but will not affect the assessment outcome.

3.2.40 The variation would increase effects on heritage assets, however changes to the significance of impacts reported within the AoS are not expected.

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Objective 18: To promote the protection and improvement of landscapes, townscapes, waterscapes and the visual resource including areas of tranquillity and dark skies.

3.2.41 The following effects on landscapes and sensitive views are anticipated:

 The diversion of the A4 north of Harmondsworth and Sipson would result in adverse impacts on landscape features including the Hillingdon Lower Colne Floodplain, Harmondsworth, and Sipson;  The A3044 would no longer be required to connect to the M25 at Junction 13. This would reduce the adverse impact on the Colne River Floodplain landscape character area between Wraysbury and King George Reservoir;  The variation would increase the impacts on the Colne Valley Regional Park, as the A4 diversion would travel through the Park west of Harmondsworth;  The variation would increase the impacts on views from properties in Harmondsworth and Sipson, as the A4 diversion would be located in close proximity. This would decrease the sense of openness in these villages. Impacts would also increase on views from the Colne Valley Way and Harmondsworth Moor; and  The variation would decrease the impacts on views from properties in Stanwell Moor and Stanwell, as the footprint of the surface access arrangements in this area would be reduced.

3.2.42 No changes to in the significance of impacts reported within the AoS are expected.

3.3 LHR- ENR VARIATION: ITERATION 4

3.3.1 The summary of the screening and assessment results for each Appraisal Objective and Appraisal Question are presented below. This follows and supports the initial screening assessment which is presented in Table 6.

3.3.2 The Screening Assessment concluded that the Appraisal Objectives and Questions relating to air quality may be subject to a potential change in the significance of effects. Further commentary on the potential change is presented below.

3.3.3 The Screening Assessment identified potential increases and decreases in impacts associated with development in or near areas which are sensitive for environmental or sustainability reasons. In addition to potential benefits for the air quality objectives, increases or decreases in environmental impacts are presented for other questions and objectives. The results of the screening process and assessment are presented below.

Objective 1: To avoid or minimise negative effects on community viability, including housing, facilities and indirect effects

3.3.4 No additional loss of housing or community facilities or increase in demand for housing and community facilities are anticipated.

3.3.5 There would be beneficial impacts on community viability:

 Improved traffic movements, and reduce journey times.

3.3.6 No changes to the significance of impacts reported within the AoS are expected.

Objective 2: To avoid or minimise disproportionate impacts on any social group.

3.3.7 The Iteration 4 variation would beneficial impacts on social groups:

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 The variation would improve traffic movements, and reduce journey times.

3.3.8 No changes to the significance of impacts reported within the AoS are expected.

Objective 3: To maintain and where possible improve the QoL for local residents and the wider population

3.3.9 The Iteration 4 variation would result in mixed effects on quality of life:

 Has the potential to improve the resilience of the surface access systems, improving quality of life;  Traffic management on the A4 and alterations to the M25 at Junction 14 and A3044 connection to Terminal 5/6 has potential to reduce the disruption to road users and severance during operation;  No additional loss of housing or community facilities are anticipated;  No change to operational employment;  No increase in noise effects, as aviation would be the main source of noise; and  Not expected to result in a change to flood risk which would affect quality of life.

3.3.10 No changes to the significance of impacts reported within the AoS are expected.

Objective 4: To maximise economic benefits and to support the competitiveness of the UK economy

3.3.11 No changes to the significance of impacts reported within the AoS are expected.

Objective 5: To promote employment and economic growth in the local area and surrounding region

3.3.12 The alterations to the M25 at Junction 14 and A3044 connection to Terminal 5/6 would improve the functioning of the surface access arrangements in the short term. However, similar to the AC’s surface access arrangements, the benefits to accessibility are expected to be negated by long term increases in transport demand for surface transport systems, including the road network. Further enhancements to the surface network may be required to ensure accessibility benefits are maintained in the long term.

3.3.13 There is potential for the traffic management on the A4 to contribute to the growth of the local economy in the surround area, including potential for a small increase in overall construction employment compared the AC’s surface access arrangements.

3.3.14 No changes to the significance of impacts reported within the AoS are expected.

Objective 6: To minimise and where possible reduce Noise impacts on human receptors

3.3.15 While variations to surface access transportation have the potential to change road traffic noise, any such effects would be localised and limited in spatial extent. Although the AoS considers noise from surface access, it is acknowledged that aviation noise is the predominant source of impact and therefore no changes to the significance of impacts reported in the AoS are expected.

Objective 7: To protect and enhance designated sites for nature conservation

3.3.16 The following potential impacts on internationally, nationally and locally designated sites are anticipated:

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 The alterations to the M25 at Junction 14 are expected to increase direct effects, primarily due to land lost from the Staines Moor Site of Special Scientific Interest (SSSI) (and therefore the SWLW SPA) when compared to the AC’s surface access arrangements.

3.3.17 No changes to the significance of impacts reported within the AoS are expected.

Objective 8: To conserve and enhance undesignated habitats10, species, valuable ecological networks and ecosystem functionality

3.3.18 The following potential impacts on undesignated habitats, internationally and nationally protected species and valuable ecological networks are anticipated:

 The variation would require a shorter diversion of the A3044 to connect the M25 Junction 14, and would reduce the requirement for new crossings or culverting of the Wraysbury River.

3.3.19 The variation would decrease the effects on priority habitats, but would not change the outcome of the assessment.

3.3.20 No changes to the significance of impacts reported within the AoS are expected.

Objective 9: To protect sites designated for geodiversity

3.3.21 No additional impacts on geodiversity are expected.

Objective 10: To minimise loss of undeveloped soils and of Best and Most Versatile agricultural land, and protect soil against erosion, contamination and degradation

3.3.22 There would be an increase in land take around M25 Junction 14. There would be a larger decrease in land take as the A3044 diversion to Junction 13 would not be required under this variation. The areas affected by land take may include areas of Best and Most Versatile agricultural land.

3.3.23 No changes to the significance of impacts reported within the AoS are expected.

Objective 11: To protect the quality of surface and groundwaters, and use water resources sustainably

3.3.24 The variation would involve changes to the quantity of watercourses to be culverted, effecting hydromorphology and the quality of surface watercourses. These effects include:

 The alterations to the M25 at Junction 14 and A3044 connection to Terminal 5/6 would remove the need for the diversion of the A3044 to run parallel with the M25 south west of the airport, as considered with the AC's surface access arrangements for LHR-ENR. This would decrease the requirement for culverting in the area adjacent to the Wraysbury River.

3.3.25 No changes to the significance of impacts reported within the AoS are expected.

Objective 12: To minimise flood risk and ensure resilience to climate change

10 Undesignated habitats are not covered by a nature conservation designation listed in Objective 7.

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3.3.26 The variation is expected to lead to a reduction in development within Flood Zone 2 and 3, as the A3044 diversion to connect with the M25 Junction 13, which travels through the Wraysbury River floodplain would not be required.

3.3.27 No changes to the significance of impacts reported within the AoS are expected.

Objective 13: To improve air quality and reduce emissions consistent with EU, national and local standards and requirements.

3.3.28 Traffic management measures on the A4 may reduce congestion somewhat but significant reductions in traffic flow are unlikely to occur. As such, it is unlikely that significant reductions in emissions from road traffic will occur and the scheme will have little impact on compliance with EU limit values. That is to say, LHR-ENR would remain at risk of impacts on compliance with limit values alongside some roads within the Greater London Urban Area Zone, both in the vicinity of the airport and in central London. The risk to compliance with EU limit values on the A4 relates primarily to the combined effects of road and airside emissions in proximity to the PCM link. This combined effect is unlikely to reduce significantly with congestion relief.

3.3.29 The existing A3113, running eastwards from Junction 14 of the M25 to the airport Southern Perimeter Road, is currently included within the PCM model. The PCM modelling shows existing exceedances of the EU limit value on this link, although the PCM projections from the 2017 Plan (both baseline and with measures scenarios) showed a rapid decrease in concentrations over time. Notwithstanding this, Iteration 4 re-introduces access to the airport from Junction 14 of the M25 and flows on this route are likely to increase with airport expansion, albeit along a revised alignment. If the realigned A3113 from the M25 to the airport is included in future PCM modelling, then there is a risk that LHR-ENR could impact on compliance with EU limit values alongside the link. This risk did not exist in the AC’s assessment since Junction 14 of the M25 was removed.

3.3.30 Iteration 4 would not affect UK Air Quality Objective Compliance. In addition, it is not likely to introduce exceedances of the UK’s air quality objectives for the protection of human health. Any benefits due to congestion relief are likely to be marginal and not significant.

3.3.31 No changes to the significance of impacts reported within the AoS are expected. Compliance with EU limit values would not be supported by the Iteration 4 Surface Access Strategy. LHR-ENR would remain at risk of worsening exceedances alongside individual roads in Central London even with this surface access strategy and likely to impact on the EU Directive zone compliance for Greater London.

Objective 14: To minimise carbon emissions in airport construction and operation

3.3.32 Iteration 4 is not expected to change the significance of carbon emissions from the AC’s surface access arrangements.

Objective 15: To minimise consumption of natural, particularly virgin non-renewable, resources.

3.3.33 The A3044 diversion to connect to M25 Junction 13 would no longer be required. This would decrease the volumetric consumption of construction materials required.

3.3.34 No changes to the significance of impacts reported within the AoS are expected.

Objective 16: To minimise the generation of waste in accordance with the principles of the Resource Efficiency Hierarchy.

3.3.35 The variation would not increase the volume of waste generated.

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3.3.36 No changes to the significance of impacts reported within the AoS are expected.

Objective 17: Conserve and where appropriate enhance heritage assets and the wider historic environment including buildings, structures, landscapes, townscapes and archaeological remains

3.3.37 The following potential effects on designated and non-designated heritage assets are anticipated:

 The A4 traffic management is expected to consist entirely of online improvements, and therefore is unlikely to harm heritage assets; and  There are Listed Buildings on the periphery of Stanwell Moor which may have views of the current A3113 and M25. The arrangement of the M25 Junction 14 and A3044 connection to

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Terminal 5/6 is not expected to generate an increase in effects relative to the AC’s surface access arrangements.

3.3.38 No changes to the significance of impacts reported within the AoS are expected.

Objective 18: To promote the protection and improvement of landscapes, townscapes, waterscapes and the visual resource including areas of tranquillity and dark skies.

3.3.39 The following effects on landscapes and sensitive views are anticipated:

 The A3044 would no longer be required to connect to the M25 at Junction 13. This would reduce the adverse impact on the Colne River Floodplain landscape character area between Wraysbury and King George Reservoir; and  There would be decreased impacts on views from properties in Stanwell Moor and Stanwell, as the footprint of the surface access arrangements in this area would be reduced.

3.3.40 No changes to the significance of impacts reported within the AoS are expected.

3.4 LHR-NWR VARIATION: M4

3.4.1 The LHR-NWR SoP sets out variations to the surface access arrangements, in particular that the primarily online improvements to the M4 were no longer considered to be a necessary improvement (Section 2) solely as a result of airport expansion. Under the SoP, HAL would undertake to reduce traffic demand to the airport and increase the number of airport users travelling on public transport. Any improvements to the M4 would be undertaken independently of airport expansion, and would subsequently be considered as part of the Government’s road investment planning process.

3.4.2 The Screening Assessment results are set out in Table 7. A shorter summary of environmental effects is provided within the Screening Table.

3.4.3 Unlike the screening assessment for LHR-ENR variations, the SoP would involve a reduction in development, as the M4 improvement works are no longer considered a necessary element of airport expansion.

3.4.4 The M4 improvements were primarily to the existing road network, and do not involve development in areas which are sensitive for environmental or sustainability reasons, so discounting these impacts from the AoS would not result in a corresponding decrease in impact.

3.4.5 Although any improvements to the M4 would take place independently of airport expansion, the noise and air quality impacts associated with traffic on the road network will not be negated by progressing these improvements independently of airport expansion. As a consequence, it would not be appropriate to discount these impacts from the AoS.

3.4.6 The Screening Assessment determined that the SoP Variation would not result in an increase or decrease in impacts which would change the significance of impacts reported within the AoS as assessed against the Appraisal Questions or Objectives.

3.4.7 No further assessment subsequent to screening was required for this scheme.

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4 VARIATIONS SCREENING ASSESSMENT TABLES

4.1.1 The results of the Screening Assessment are presented within the summary tables within this section.

Table 4 SOP Variation Elements Sop Sop Variation Elements Screening Table LGW-2R Construction Phasing Arrangements Table 5 LHR-ENR Iteration 3 Surface Access Arrangements Table 6 LHR-ENR Iteration 4 Surface Access Arrangements Table 7 LHR-NWR Surface Access Arrangements Table 8

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Table 5 LGW-2R Variation Screening Assessment: Phasing

Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

Community 1. To avoid or 1. Will it lead to a Significant Negative effect (--) minimise loss of housing 11 negative effects and community The loss of the following housing and community facilities : on community facilities?  168 residential properties likely to be demolished for airport expansion; viability, including  up to 37 residential properties could be demolished for surface access, since they fall within the housing, buffer zone for construction works; facilities and indirect effects.  potential secondary impacts of relocated households on existing communities;  Trent House care home;

 loss of industrial/employment land; The phasing of construction for The land take No further airport facilities, and surface effects of the assessment is  two places of worship (a church used by Seventh Day Adventists, and a Hindu temple); The significance of access systems would not surface access proposed, because effects is not  one charity facility - Outreach 3 Way, which helps people with learning difficulties; result in a change in the arrangements are no change to the expected to change. number of houses or expected to be in overall significance  five pre-schools/ nurseries; community facilities lost. the same location. is expected.  Crawley Rugby club, with its sporting and social facilities;  The northern part of Rowley Wood;  other formal and informal recreation sites;  public rights of way;  cycle routes; and  Impacts on local journey times, either from severance or increased traffic. Mitigation has been recommended.

2. Will it lead to Minor Negative effect (-) increasing High demand scenarios indicate 9,300-18,400 homes would be required up to 2030. The phasing of construction for No further The demand demand for airport facilities, and surface assessment is The significance of scenarios would housing and Additional housing expected to be required is 136 additional housing units per local authority per year. access systems would not proposed, because effects is not not be affected by community result in a change in demand no change to the Additional spaces in local schools are likely to be required and two additional GPs per local authority to expected to change. construction facilities? for housing and community overall significance 203012. phasing. facilities. is expected. There is also likely to be a need for additional parks or open spaces.

3. Will there be The phasing of airport The significance Minor Negative effect (-) No further indirect effects elements would not lead to any of the air quality Traffic movements - may lead to more traffic and increased journey times. This may lead to issues of assessment is on community additional indirect effects on The significance of and noise effects severance, loss of sense of place, breakdown in community cohesion, and a reduction in the quality of proposed, because viability? community viability, although effects is not which impact upon amenity within the community. no change to the the timing of impacts expected to change. community overall significance Air Quality - 51,328 people will experience a rise in annual mean NO2 levels. No exceedances of UK associated with construction viability will not is expected. air quality objectives are anticipated13. may change. change.

11 Airports Commission, 2014. Community: Impact Assessment, pp. 9-10. [online] Accessed 24/12/2015. 12 Airports Commission, 2014. Local Economy Impacts: Assessment, p. 109 [online] Accessed 24/12/2015. 13 Airports Commission, 2015. Quality of Life: Equalities Impacts Report. [online] Accessed 24/12/2015.

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Table 5 LGW-2R Variation Screening Assessment: Phasing

Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

Noise - There is a predicted increase of 16,200 people exposed to airspace noise exceeding 54dB 14 LAeq16 hr by 2030, which increases further to 21,300 by 2050 . Increases in exposure to levels of noise >63 dB LAeq,16hr are expected to be 400 in 2030, 200 in 2040 and 400 in 2050.

Strategic development- No allocated housing sites will be lost as a result of airport expansion. However, housing allocations close to the edge of the airport site in Crawley and on the northern edge of Horsham may be subject to noise effects.

2. To avoid or 4. Will it minimise Minor negative effect (-) minimise disproportionate With the loss and relocation of housing and of some community facilities such as day-care and disproportionate negative effects The phasing of airport nurseries, Trent House Care Home, the Outreach 3 Way facility, a Hindu temple and a church used by No further impacts on any on particular elements would not lead to any The community Seventh Day Adventists, recreational ground and transport links, disproportionate effects may be assessment is social group. regions, users additional effects on particular The significance of facilities affected experienced by vulnerable social groups within the area. Furthermore, indirect effects due to increased proposed, because or vulnerable regions, users or vulnerable effects is not will be the same traffic, reduced air quality and increased noise effects may be experienced disproportionately by such no change to the social groups? social groups, although the expected to change. as originally groups. overall significance timing of impacts associated assessed. is expected. The population around Crawley is predominantly white but there is also a significant Black, Asian, and with construction may change. minority ethnic (BAME) community across local wards, particularly at Langley Green. There is potential for BAME groups to therefore experience disproportionate effects.

Quality of 3. To maintain and 5. Will it help to Traffic Volume Life where possible maintain and improve the improve quality Significant disruption to road users and severance of small local communities will be experienced quality of life for of life? during the construction phase of the scheme, causing distress and anxiety to residents. local residents During the operational period of the scheme, improved infrastructure and access to public transport and the wider may provide improvements to QoL in the short term, however these are expected to be negated by long population. term increasing demand for infrastructure. Housing and Communities Loss of housing/ forced moves will cause distress and have significant adverse impacts upon wellbeing. Social isolation likely to increase during construction from loss of community facilities, resulting in a The phasing of airport The significance No further reduction in the QoL of those directly affected by relocation or disruption during the construction period. elements would not lead to any of the air quality assessment is The significance of additional effects on quality of and noise effects proposed, because New housing and community facilities will provide greater opportunities for leisure. effects is not life, although the timing of which impact upon no change to the expected to change. Employment and the Economy impacts associated with quality of life overall significance construction may change. would not change. is expected. New employment and business from an expanded airport will be of significant benefit to QoL locally and nationally from enhanced local and national economic growth. Noise Local exposure to construction noise and vibration can cause annoyance, for the duration of works. Increases in significant community annoyance due to aircraft noise exposure. Increases in effects which would lead to negative health outcomes, including due to sleep disturbance. Loss of sleep can increase anxiety and hypertension. Mixed impacts on QoL of school children: some schools could be at risk of increased exposure to excessive aircraft noise levels (potentially leading to impaired learning). Some schools may be subject

14 All noise figures are predicted changes in population exposures in the do something, relative to the do minimum for central scenario assumptions.

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Table 5 LGW-2R Variation Screening Assessment: Phasing

Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

to noise reductions, which could reduce negative effects on cognitive development. Increased noise levels in primary schools can delay reading development. Air Quality Poor air quality has a direct impact upon sensitive receptors, exacerbates symptoms surrounding cardiovascular and impaired lung functions and has strong dose-response relations with increased morbidity and mortality. Access to nature and cultural heritage Indirect potential negative impact upon wellbeing during construction as a consequence of a reduction in recreational amenity of the Crawley public rights of way and the Tandridge Border Path. Indirect temporary loss of high amenity during the construction phase could result in potentially negative impacts on wellbeing during construction. Indirect negative impact on wellbeing due to permanent loss of Ancient Woodland during construction and operational phases. Indirect potential negative impact upon wellbeing as a consequence a reduction in recreational amenity for users of the Ifieldwood and the Tandridge Border Path during operation. Onsite mitigation and offsite enhancement measures of high amenity areas could potentially indirectly off-set any negative impacts on wellbeing during operational phase of the airport. Flooding Direct potential negative impact upon wellbeing during construction and operation as a consequence of potential and perceived increase in flood risk. It is acknowledged that detailed design at the next stage will identify opportunities to mitigate flood risk.

Economy 4. To maximise 6. Will it enhance Significant Positive effect (++) economic economic Direct impacts: benefits and to growth? support the The total passenger benefits are valued at £48.5bn and include: competitiveness of the UK  Lower fares: £64.5bn; economy.  Frequency benefits: £4.0bn;  Reduced delays: £0.8bn; No further The phasing of airport assessment is  Other direct benefits are as follows: The significance of elements would not lead to any proposed, because effects is not  Total producer impact: £-65.1bn; and additional effects on economic no change to the expected to change. growth. overall significance  Government revenue: £4.6bn. is expected. Wider economic impacts:

 Business output benefits: £1.2bn; and  Tax wedge: £-1.1bn to £0.1bn The trade benefits have been estimated at either £10.9bn, £20.0bn, or £59.5.0bn depending on the approach taken. However, it should be noted that these are not additive to the other wider economic impacts. Total benefits (excluding trade and producer impacts): £74.1 – 75.3bn

7. Will it contribute Significant Positive effect (++) The phasing of airport The significance of No further to sustainable elements would not lead to any assessment is Although there will be local impacts, the extent of employment impacts at a national level remains effects is not additional effects on proposed, because unclear (due to displacement). expected to change. employment, although the no change to the

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Table 5 LGW-2R Variation Screening Assessment: Phasing

Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

growth in It is also anticipated that many jobs will be created during the construction phase, although these may timing of employment overall significance employment? again be displaced from other potential construction activities. associated with construction is expected. activities would change.

8. Will it support Significant Positive effect (++) the Three types of wider productivity-related impacts are estimated: No further competitiveness The phasing of airport assessment is The significance of of the UK  enhanced productivity through increased trade and associated spin-off benefits; elements would not lead to any proposed, because effects is not economy? additional effects on no change to the expected to change.  change in tax revenue due to relocation of employment to areas with different levels of competitiveness. overall significance productivity;; and is expected.  increased business output.

5. To promote 9. Will it Neutral (0) employment incorporate and economic accessibility Long term increases in surface passengers associated with the airport are anticipated. In addition, The surface growth in the improvements, there are also expected to be increases in the use of surface access systems by additional users not The timing of any disruption to access systems No further local area and particularly with associated with the airport. accessibility caused by affected by the assessment is surrounding key local The significance of The improvements to surface access planned under the do minimum scenario are expected to construction activities would phasing proposed, because region. employment effects is not accommodate the additional passengers associated with airport expansion. However, long term change, however this would arrangements no change to the centres and expected to change. increases in airport and non-airport related transport demand are expected to negate any network not result in an additional would be the overall significance areas of high benefits to journey times for other users of surface transport systems around the airport. As a impact. same as originally is expected. unemployment? consequence no accessibility benefits to key local employment centres (such as Crawley) are assessed. anticipated15. Further enhancements to the surface transport network may be required to ensure accessibility benefits are maintained in the long term.

10. Will it contribute Significant Positive effect (++) to growth in the local economy? The DfT developed a range of local employment estimates following from the AC’s original estimates. These indicated that between 9,000 and 21,000 additional local jobs would be generated by 2030 with between 25,000 and 60,000 generated by 205016. The timing of any disruption to No further The quantity and distribution of high skilled jobs has not been determined at this stage of the accessibility caused by assessment is assessment. construction activities would The significance of proposed, because change, however this would effects is not It is considered likely that airport expansion will serve as a catalyst to business investment in the no change to the not result in an additional expected to change. surrounding area, continuing to attract high value firms. overall significance impact on growth in the local is expected. Employment and business which develops, or is maintained by the expansion of the airport will benefit economy. the local economy and enhance local economic growth.

Noise 6. To minimise 11. Will it avoid or Predominant Significant Negative effects (--) No further and where reduce the The timing of any noise The significance of assessment is possible reduce harmful effects associated with construction effects is not proposed, because noise impacts due to exposure Construction phase impacts are likely to be negative, with potential for significance at sensitive activities will change, however expected to change. no change to the of people and

15 Jacobs, 2014. Local Economy Impacts: Assessment, p. 96. [online] Accessed 24/12/2015. 16 Department for Transport, 2017. Airport Capacity in the South East: Updated Appraisal Report.

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Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

on human sensitive receptors near to the new runway or along construction routes. The effects cannot yet be assessed in this would not result in overall significance receptors. buildings to detail but as a worst case estimate can be considered as potentially Significant Negative (--). additional noise effects. is expected. noise? The effects of changes in airspace noise exposure on the local population from the LGW-2R scheme (assessment of need carbon traded scenario) are considered to be predominantly Significant Negative (--). The effects of changes in airspace noise exposure on local NSBs from the LGW-2R scheme (assessment of need carbon capped scenario) are considered to be mixed Positive (+) / Negative (-). The local effects of ground noise from the LGW-2R scheme are considered to be Positive (+). The overall effects of the LGW-2R scheme on the health outcomes assessed are considered to be Significant Negative (--), since it would result in increases in disability-adjusted life year (DALYs) lost compared with the Do minimum. The local effects of airspace noise from the LGW-2R scheme on children’s cognitive development are considered to be mixed Significant Positive/Negative (++/-). The national effects of the LGW-2R scheme are considered to be Positive (+).

Biodiversity 7. To protect and 12. Will it affect Significant Negative effect (--) enhance internationally, designated nationally and International Sites: sites for nature locally Mole Gap to Reigate Escarpment Special Area of Conservation (SAC) conservation. designated biodiversity Ashdown Forest SAC and Special Protection Area (SPA) sites? Significant adverse effects have been identified with regard to air quality impacts associated with increased traffic flow, and direct and indirect impacts upon supporting habitat as a result of the surface access strategy National Sites Glover’s Wood SSSI Leith Hill SSSI

Vann Lake and Ockley Woods SSSI The phasing of airport The sites affected No further elements would not lead to any by the phasing assessment is Reigate Heath SSSI The significance of additional effects on arrangements proposed, because effects is not Mole Gap to Reigate Escarpment SSSI biodiversity sites, although the would be the no change to the expected to change. timing of impacts associated same as originally overall significance Hedgecourt SSSI with construction may change. assessed. is expected. Weir Wood Reservoir SSSI Wakehurst and Chiddingly Woods SSSI Cow Wood and Harrys Wood SSSI St Leonards Wood SSSI Potential impacts principally associated with air and water quality changes that could result in adverse effects to the habitats and species interest features of these sites. Local Sites Willoughby Fields Site of Nature Conservation Interest (SNCI) / local nature reserve (LNR), Rowley Wood SNCI Horleyland Wood SNCI

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Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

Bridges Wood proposed Site of Nature Conservation Interest (pSNCI) Bridges Fields pSNCI The Roughs SNCI Potential impacts including, loss, disturbance, air and water quality changes.

8. To conserve 13. Will it conserve Significant Negative effect (--) and enhance and enhance undesignated undesignated Habitats habitats, habitats, lowland mixed deciduous woodland, including ancient woodland; species, internationally valuable and nationally hedgerow including ancient hedgerow; Limited additional The phasing of airport The sites affected ecological protected assessment is rivers and brooks including canalised or conduited channel; and elements would not lead to any by the phasing networks and species and The significance of recommended in additional effects on ecological arrangements ecosystem valuable effects is not order to establish ponds networks, although the timing would be the functionality. ecological expected to change. that the likely change of impacts associated with same as originally networks, such Species does not result in a construction may change. assessed. as priority significant change. habitats and A range of species protected under UK (and EU) wildlife legislation including but not limited to bat priority species (inc Bechsteins), dormice, and great crested newts. In addition it is likely the area will support species? species of principal importance as identified under Section 41 of the NERC Act 2006 Potential impacts including, loss, disturbance, habitat severence/ fragmentation, air and water quality changes, mortality.

14. Will it increase Assessment significance: Significant Negative effect (--) the exposure of wildlife to International Sites: transport noise, Mole Gap to Reigate Escarpment SAC air pollution, and water Ashdown Forest SAC and SPA pollution? Significant adverse effects have been identified with regard to air quality impacts associated with increased traffic flowas a result of the surface access strategy. National Sites Glover’s Wood SSSI The phasing of airport The sites affected No further Leith Hill SSSI elements would not lead to any by the phasing assessment is The significance of additional effects on wildlife arrangements proposed, because Vann Lake and Ockley Woods SSSI effects is not due to pollution, although the would be the no change to the expected to change. Reigate Heath SSSI timing of impacts associated same as originally overall significance with construction may change. assessed. is expected. Mole Gap to Reigate Escarpment SSSI Hedgecourt SSSI Weir Wood Reservoir SSSI Wakehurst and Chiddingly Woods SSSI Cow Wood and Harrys Wood SSSI St Leonards Wood SSSI Potential impacts principally associated with air and water quality changes that could result in adverse effects to the habitats and species interest features of these sites.

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Table 5 LGW-2R Variation Screening Assessment: Phasing

Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information Local Sites Willoughby Fields SNCI/LNR Rowley Wood SNCI Horleyland Wood SNCI Bridges Wood pSNCI Bridges Fields pSNCI The Roughs SNCI Potential impacts including, disturbance, air and water quality changes. Habitats lowland mixed deciduous woodland, including ancient woodland; hedgerow including ancient hedgerow; rivers and brooks including canalised or conduited channel; and ponds Species A range of species protected under UK (and EU) wildlife legislation including but not limited to bat species (inc Bechsteins), dormice, and great crested newts. In addition it is likely the area will support species of principal importance as identified under Section 41 of the NERC Act 2006 Potential impacts including disturbance, habitat severance/fragmentation, air and water quality changes, mortality.

Soil 9. To protect sites 15. Will it preserve, Neutral effect The sites affected No further designated for protect and The phasing of airport by the phasing assessment is A review of sites which are designated for geodiversity reasons, including geological SSSIs and The significance of geodiversity. improve elements would not lead to any arrangements proposed, because regionally important geological sites (RIGS) has been undertaken. Newdigate (North) RIGS is situated effects is not geodiversity? additional effects on would be the no change to the 5 km to the northwest of London Gatwick Airport. No impacts on the RIGS in relation to loss of expected to change. tranquillity from noise, direct land take, air quality effects on exposed geology, and contamination are geodiversity. same as originally overall significance anticipated. assessed. is expected.

10. To minimise loss 16. Will it maximise Significant Negative effect (--) of undeveloped construction on The land take soils and of previously This option scheme entails land take of 624 ha, with up to further 78 ha potentially affected by surface No further 17 The phasing of airport required for the Best and Most developed land, access. assessment is elements would not lead to any The significance of phasing Versatile minimise use of proposed, because The site area of the airport incorporates approximately 421 ha of agricultural land, a proportion of which additional effects on previously effects is not arrangements agricultural greenfield land? no change to the is likely to be BMV agricultural land. Agricultural land is a finite and irreplaceable resource, and developed land, or greenfield expected to change. would be the land, and overall significance although compensation will be provided to land owners, the loss of the land cannot be mitigated. land. same as originally protect soil is expected. assessed. against erosion, As a consequence of the site location, a high proportion of the land take required is from agricultural contamination land, the quantity of land PDL should be considered a correspondingly small proportion.

17 Jacobs, 2014. 10. Place: Assessment, pp. 16-18. [online] Accessed 24/12/2015.

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Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

and 17. Will it lead to the Negative effect (-) degradation. The land take disturbing, The phasing of airport No further Development may result in soil loss or burial, physical damage including compaction, sealing, and required for the harm, elements would not lead to any assessment is structural damage, changes to soil water regime, effects on organic matter and soil stripping and The significance of phasing contamination additional effects due to proposed, because storage. In addition, development has the potential to result in contamination of soil, resulting in risks to effects is not arrangements or loss of soil contamination, the timing of no change to the human health or the environment. expected to change. would be the resources? the construction effects may overall significance same as originally change. is expected. The use of large areas of previously undeveloped land will affect the quality of soil and land resources assessed. meaning these areas of land will no longer be suitable for other uses, including farming.

Water 11. To protect the 18. Will proposals Negative effect (-) quality of have adverse surface and effects on the Physical impacts are considered in question 19 below. Water quality impacts arising from polluted ground waters, achievement of runoff during construction and operation. The scheme could lead to a decrease in pesticides and and use water the herbicides applied to the land. resources environmental A further risk during construction is posed by the historic landfill within the proposed development The watercourses sustainably. objectives The phasing of airport No further footprint, posing a risk if contaminants are mobilised. affected by the established elements would not lead to any assessment is The significance of phasing under the Water A number of measures would be considered to improve water quality. additional effects on the proposed, because effects is not arrangements Framework environmental objectives no change to the expected to change. would be the Directive? Waste water will continue to be sent to an expanded Crawley Sewage Treatment Works (STW) for established under the Water overall significance same as originally treatment. Alternatively a local treatment plan would be installed to allow contaminated runoff to be Framework Directive. is expected. treated on site. Additional sewage and waste water wetland treatment system would be built. assessed. To ensure that water resources are used efficiently rainwater harvesting will be installed along with other water saving design. Discharges could affect Glovers Wood SSSI which is hydrologically connected via minor watercourses to Gatwick although it is unlikely given its location upstream of the airport.

19. Will it result in Negative effect (--) the modification of Estimated that approximately 7km of existing watercourse would be replaced with diverted/realigned watercourses? channels. Of particular note is: the diversion of approximately 1km of the River Mole to the west of the airport; and The watercourses The phasing of airport No further the diversion of the Crawter’s Brook and the addition of a weir to compensate for a 2m reduction in bed affected by the elements would not lead to any assessment is level at the Crawter’s Brook/River Mole confluence. The diversion with appropriate mitigation will The significance of phasing additional effects due to proposed, because enhance the existing engineered channel as the River Mole would be removed from approximately effects is not arrangements modification of watercourses, no change to the 600m of existing culvert and engineered channel. Whilst the weir has the potential to have impacts in expected to change. would be the the timing of the construction overall significance terms of creating a barrier to flow and sediment processes as well as fish migration and can act as a same as originally effects may change is expected. segregating factor for the river corridor habitats. assessed. Changes to the sedimentation processes can lead to deterioration in water quality and could impact the waterbody status should the sediment contain contaminants. No new culverting is proposed.

20. Will it result in Negative effect (-) The phasing of airport The watercourses No further the loss in elements would not lead to any affected by the assessment is productivity of Replacement of 7km of the existing watercourse with diverted/realigned channels and diversions of additional effects due to The significance of phasing proposed, because fisheries? River Mole and Crawters Brook may cause a deterioration of the ecological status, which could affect modification of the productivity effects is not arrangements no change to the the productivity of fisheries. In addition the creation of a weir may prevent the passage of fish. of fisheries, the timing of the expected to change. would be the overall significance construction effects may same as originally is expected. change assessed.

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Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

21. Will it lead to an Significant Negative effect (--) increase in the consumption of Total annual potable water demands for 2025 and 2050 are 0.77 Mm³/year (million cubic metres per available water year) and 1.33 Mm³/year, respective increases of 0.05 Mm³/year and 0.61 Mm³/year from 2012 demands. The phasing of airport resources? No further elements would not lead to any A doubling of 2012 passenger numbers has been forecast after the completion of the second runway at assessment is additional effects on the The significance of Gatwick to 69.4 million per year by 2050, which despite water efficiency measures reducing demand proposed, because consumption of water effects is not per passenger by 10% to 0.0192 m3 pp, a reduction on 0.0310m3 in 2010 would result in an increase no change to the resources, although the timing expected to change. in demand for water at the airport to 1.33 Mm3pa by 2050. No figures are available for 2085 due to overall significance of construction effects would limitations in the forecast figures and information within the WRMP. is expected. change. Sutton and East Surrey Water state they currently have a surplus in the water resource zone and are completing resilience measures to supply Gatwick Airport from alternative water treatment works. Construction of the scheme will lead to short term increases in water demand.

12. To minimise 22. Will it increase Negative effect (-) flood risk and flood risk ensure through Increase in impermeable areas, without suitable mitigation, could lead to runoff rates greater than the resilience to increased run greenfield rate resulting in increased risks of flooding elsewhere. There are methods of reducing flood risk. climate change. off? The impermeable The phasing of airport No further area required for Conservative greenfield runoff rates have been used to estimate the required attenuation volumes. Two elements would not lead to any assessment is The significance of the phasing schemes have been put forward for the storage a ‘Business as Usual’ and an ‘Exemplar scheme’. additional effects on flood risk, proposed, because effects is not arrangements although the timing of no change to the Business as Usual scheme involves collector drains, tanks and culverts prior to pumping to an expected to change. would be the construction effects would overall significance attenuation pond and discharge to the River Mole at greenfield rates. same as originally change. is expected. assessed. Discharge route for entire site is not known, meaning additional attenuation volumes are required. This may mean that this is an increase in flood risk. Exemplar Scheme may provide a volume of storage near the Jacobs estimates, however, refinement of the types of SuDs incorporated will need to be reviewed to ensure contamination is prevented.

23. Will it increase Negative effect (-) area of development Approximately half of the area proposed for development is located in Flood Zones 2 and 3 and at risk within areas at from fluvial flooding. Flooding from the River Mole and Gatwick Stream are recognised problems in the risk of flooding? area, with two flood risk alleviation schemes currently being implemented. The Upper Mole Flood Alleviation Scheme is anticipated to provide protection up to a 2% annual exceedance probability (AEP) flood event, whilst the Gatwick Stream Flood Alleviation Scheme is designed to provide protection up to The phasing of airport The areas required No further a 1% event. This situation should represent the baseline in 2025, however may not be sufficient to elements would not increase for the phasing assessment is The significance of cover the predicted increases in peak river flows of between 35% and 70% by 2085. This in turn may development within areas at arrangements proposed, because effects is not impact on increased developed areas at risk outside the airport development. risk of flooding, although the would be the same no change to the expected to change. timing of the construction as originally overall significance Proposed area for the runway and terminal buildings cover areas of medium surface water flood risk, effects would change. assessed. is expected. with areas to the west of the site at high surface water risk. Risks of groundwater flooding or flooding from reservoirs at the proposed site are considered negligible. Peak flow and rainfall is expected in increase from the baseline to 2086, meaning that developments on the floodplain and zones susceptible to groundwater flooding could be at risk from increases in rainfall intensity.

24. Will it be able to Negative effect (-) The areas The phasing of airport No further adapt to climate The significance of required for the Without appropriate mitigation the scheme could result in increased risks to itself and sites elsewhere elements would not increase assessment is change? effects is not phasing as a result of increased peak river/overland flows, runoff rates from across the scheme and altered development within areas at proposed, because expected to change. arrangements volumes available for abstraction for water use. risk of flooding, although the no change to the would be the

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Table 5 LGW-2R Variation Screening Assessment: Phasing

Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

Scheme promoter has applied a 20% increase in peak flows and rainfall, a 40% allowance will need to timing of construction effects same as originally overall significance be assessed to be compliant with current guidance. would change. assessed. is expected. The WRMP demonstrates that sufficient water is available to meet potable and non- potable requirements.

Air Quality 13. To improve air 25. Will it support Negative effect (-) quality and compliance with 18 reduce local, national A reassessment of compliance with the EU Air Quality Directive taking account the Government’s The magnitude of No further emissions and European 2017 Air Quality Plan indicates that LGW-2R will not impact on compliance with EU limit values. This The phasing of airport the impact may be assessment is consistent with air quality conclusion has low vulnerability to uncertainties since sensitivity testing demonstrated that the scheme elements would not affect reduced but the proposed, because EU, national requirements or is at low risk of impacting on compliance with limit values. compliance with air quality significance of the no change to the and local legislation? NOx and PM2.5 emissions are currently projected to exceed the NECD target for 2030 – but the requirements or legislation. effect is not overall significance standards and increase with the scheme is a very small fraction of the target. expected to change is expected. requirements. The maximum predicted annual mean NO2 concentration with the scheme in place at any receptor in Principal Study Area is 38.6µg/m3 in 2030.19

26. Will it reduce the Significant Negative effect (- -) exposure to air There are no predicted exceedances of the air quality objective at any receptor location with quality issues The phasing of airport LGW-2R. The scheme will increase exposure to pollution at 20,985 properties, of which 62 The magnitude of No further for local elements would not affect communities There is a risk that with opening earlier than 2030 that the impact may be assessment is are considered ‘at risk’ (>32μg/m3). exposure to air quality issues and sites reduced but the proposed, because exceedances of air quality objectives could occur. for local communities or nature significance of the no change to the designated for conservation, although the The scheme results in worsened exceedances of critical levels and critical loads over sites effect is not overall significance nature timing of construction effects conservation? designated for nature conservation at 9 out of 10 sites assessed (including Mole Gap to expected to change is expected. may change. Reigate Escarpment SAC), with one site showing a reduction in exposure to air pollution.

Increase in national emissions of NOx and PM2.5.

Carbon 14. To minimise 27. Will the Significant Negative effect (--) carbon approach to the emissions in development be Over the 60-year Appraisal Period (2025 to 2085), under the Carbon-Capped scenario, it is airport consistent with forecast that the development of a second runway at Gatwick Airport will result in the No further 20 construction overall carbon emission of a further 192.1 MtCO2 over the baseline case . The phasing of airport assessment is

and operation. requirements? elements would not affect proposed, because The significance of Over the same Appraisal Period under the Carbon-Traded scenario, it is forecast that the compliance with carbon no change to the effects is not development of a second runway at Gatwick Airport will result in the emission of a further emissions requirements. overall significance 21 expected to change. 200.5 MtCO2 over the baseline case . is expected.

In both cases, construction emissions will contribute a further 3.9 MtCO2e to UKemissions, however, this is a one-off impact at the beginning of the Appraisal Period22.

28. Will the The phasing of airport The significance of No further approach Significant Negative effect (--) elements would not affect effects is not assessment is minimise carbon emissions, but may expected to change. proposed, because carbon affect the timing of emissions no change to the

18WSP, October 2017, 2017 Plan Update to Air Quality Re-analysis. 19 Jacobs, 2015. Module 6: Air Quality Local Assessment - Detailed Emissions Inventory and Dispersion Modelling, p. 64. [online] Accessed 06/01/2016 20 Jacobs, 2014. Module 8. Carbon: Assessment, Table 3.17. [online] Accessed 04/01/2016. 21 Jacobs, 2015. Module 8. Carbon: Further Assessment, Table 1.12 [online] Accessed 04/01/2016. 22 Jacobs, 2014. Module 8. Carbon: Assessment, Table 3.17. [online] Accessed 04/01/2016.

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Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

emissions Over the 60-year Appraisal Period (2025 to 2085), under the carbon-traded scenario, it is associated with construction overall significance associated with forecast that the development of a second runway at Gatwick Airport will result in the emission of an effects. is expected. 23 surface additional 9.7 MtCO2 due to Passenger and Staff Surface Access over the baseline case . transportation? In the DfTs revised carbon-capped scenario, demand is unaffected by the abatement measures implemented, so the surface access CO2 estimates are the same as in the carbon-traded Case Emissions from freight transport movements are also likely to rise, but these were not quantified in the DfT’s assessment. It is recommended that they be assessed by the Scheme Promotor during the Detailed Design stage.

Resources 15. To minimise 29. Will it be Significant Negative effect (--) No further and Waste consumption of possible to The phasing of airport assessment is natural, minimise the Consumption of large volumes of construction material. Operational consumption reduced by comparison with construction phase. elements would not affect The significance of proposed, because particularly consumption of overall consumption of natural effects is not no change to the virgin non- natural resources but would affect the expected to change. overall significance renewable, resources? timing of consumption. of impact is resources. expected.

16. To minimise the 30. Will it be Significant Negative effect (--) generation of possible to Generation of large volumes of construction waste that could be sent to landfill. No further waste in minimise waste The phasing of airport assessment is accordance generated Volumes of waste to be generated during operation are likely to be greatly reduced by comparison with elements would not affect The significance of proposed, because with the during construction. generation of waste but would effects is not no change to the principals of the construction affect the timing of waste expected to change. overall significance resource and operation? Forecasts for waste generation in operation are the lowest of all three schemes, across all operational generated during construction. of impact is efficiency scenarios. expected. hierarchy.

Historic 17. Conserve and 31. Will it affect the Significant Negative effect (--) Environment where significance of appropriate internationally Land take study area (including surface access corridors) enhance and nationally Construction activities including the demolition or partial demolition of structures will impact on 22 heritage assets designated Listed Buildings (Grade II* and II) resulting in their total or partial loss. Total loss is substantial harm. and the wider heritage assets Partial loss could result in assets being put at risk. Partial loss can also result in substantial harm. The phasing of airport The assets No further historic and their elements would not generate affected by the environment settings? assessment is The significance of assets lying outside of the land take but associated with those within it will be at risk additional effects on The significance of phasing including proposed, because of harm. designated heritage assets, effects is not arrangements no change to the buildings, although the timing of impacts expected to change. would be the Intermediate Study Area overall significance structures, associated with construction same as originally landscapes, is expected. Construction and operation will impact on the setting of 2 scheduled monuments, 6 Listed Buildings may change. assessed. townscapes (Grade II) and 2 conservation areas. This will result in harm to the significance of the assets. and archaeological Outer study area remains. Operation of the scheme will impact on the setting of 2 Scheduled Monuments, 153 Listed Buildings (all Grades) and 5 Conservation Areas. This will result in harm to the significance of the assets.

23 Jacobs, 2014. Module 8. Carbon: Assessment, Table 3.17. [online] Accessed 04/01/2016.

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Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

32. Will it affect the Significant Negative effect (--) significance of non-designated Land take Study Area (including surface access corridors) heritage assets 35 assets are present and 12 archaeological notification areas. and their settings? Total removal of any archaeological remains during construction activities and earth-moving activities in particular. The phasing of airport The assets No further elements would not generate affected by the The significance of non-designated remains will be subject to substantial harm or total loss. assessment is additional effects on non- The significance of phasing proposed, because Intermediate Study Area designated heritage assets, effects is not arrangements no change to the although the timing of expected to change. would be the 20 assets are present and one archaeological notification area. overall significance construction effects may same as originally is expected. Any impact within the intermediate area will be to the significance of the setting of the assets. This has change. assessed. the potential to result in harm to the significance of the assets. Outer Study Area None identified. HER search does not extend into outer Study Area. Any impact within the outer area will be to the significance of the setting of the assets. This has the potential to result in harm to the significance of the assets.

33. Will it conserve Significant Negative effect (--) or enhance heritage assets No beneficial impacts have been identified. However, it is possible that following mitigation positive The phasing of airport and the wider outcomes could be realised through some enhancement to Conservation Areas and community elements would not conserve The assets No further historic engagement and by addressing Heritage at Risk (including those that become at risk as a result of the or enhance heritage assets affected by the assessment is environment scheme), improving the setting of heritage assets, together with opportunities for community and the wider historic The significance of phasing proposed, because including engagement including improving access to and/or interpretation, understanding and appreciation of environment, or result in effects is not arrangements no change to the landscapes, heritage assets. additional effect on these expected to change. would be the overall significance townscapes, assets, although the timing of same as originally is expected. buildings, construction effects may assessed. structures, and change. archaeological remains?

34. Will it harm Significant Negative effect (--) significance of heritage assets, There is likely to be increased light and noise levels from construction and operation in addition to any for example lights and noise from aircraft whilst on the ground and in flight. from the The phasing of airport The assets The setting of ten designated heritage assets could be affected within 300m of the scheme area (six No further generation of elements would not lead to affected by the Grade II Listed Buildings, two Scheduled Monuments and two Conservation Areas) and from 300m to assessment is noise, additional harm to the The significance of phasing 2km the setting of a further 160 designated assets could potentially be affected (five Grade I, four proposed, because pollutants and significance of heritage assets effects is not arrangements Grade II*, 144 Grade II Listed Buildings, two Scheduled Monuments and five Conservation Areas. no change to the visual intrusion? although the timing of impacts expected to change. would be the overall significance The setting of twenty non-designated assets could be affected. associated with construction same as originally is expected. may change. assessed. Historic landscape and townscape character will be affected. There is unlikely to be an impact on below-ground archaeological remains. Data was only available for the intermediate study area i.e. 300m of the scheme area.

Landscape 18. To promote the 35. Will it protect The phasing of airport The areas No further protection and and enhance elements would not lead to The significance of affected by the assessment is improvement of nationally and Negative effect (-) additional impacts on effects is not phasing proposed, because landscapes locally landscape, townscape and expected to change. arrangements no change to the townscapes, designated waterscape although the would be the

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Table 5 LGW-2R Variation Screening Assessment: Phasing

Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Question Potential Change To Effects Limitations Likely Change To Further (Increase Impact/ Decrease Based On Significance Assessment To Be Impact/ Unknown) Existing Taken (Or N/A) Information

waterscapes landscape, National Landscape Designations: Potential indirect impacts from new lighting and the direction / height timing of impacts associated same as originally overall significance and the visual townscape and / number of flights: Surrey Hills Area of Outstanding Natural Beauty (AONB), High Weald AONB, Kent with construction may change. assessed. is expected. resource, waterscape? Downs AONB. including areas of tranquillity Local Landscape Designations: Long distance views from the Surrey Area of Great Landscape Value and dark skies. which adjoins the Surrey Hills AONB. Potential indirect impacts from new lighting and the direction / height / number of flights. Local Townscape Designations: Effects on tranquillity of Ifield and Langley Townscape Character Areas (TCAs) Other areas with landscape character value: Loss of Ancient Woodland on Bonnetts Lane. The LW8 Northern Vales character area would experience the greatest impact.

36. Will it lead to Significant Negative effect (- -) The areas The phasing of airport No further impact on affected by the Potential for deterioration in valued views and vistas from Surrey Hills AONB, Kent Downs AONB and elements would not lead to assessment is sensitive views The significance of phasing High Weald AONB due to new lighting and the direction / height / number of flights over the AONBs. additional impacts on sensitive proposed, because and their effects is not arrangements views although the timing of no change to the settings? expected to change. would be the The most significant views towards the proposed scheme would be from B2036 and Radford Road impacts associated with overall significance same as originally properties, Crawley, public rights of way and the Tandridge Border Path during construction; and would construction may change. is expected. continue into operation for Ifieldwood and the Tandridge Border Path. assessed.

37. Will it lead to a Negative effect (-) The areas The phasing of airport No further loss of affected by the Potential for increased numbers of aircraft over-flying areas of higher tranquillity, including AONBs and elements would not lead to assessment is tranquillity and The significance of phasing to the east and west of the airport. Potential for increased aircraft noise and views of aircraft in flight. additional effects on tranquillity proposed, because increase in light effects is not arrangements or light pollution although the no change to the pollution? expected to change. would be the There is likely to be increased light levels from construction and operational lighting, in addition to any timing of impacts associated overall significance same as originally lights from aircraft whilst on the ground and in flight. Lighting from the airport will particularly affect open with construction may change. is expected. views to the west around Ifieldwood. assessed.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) Community 1. To avoid or 1. Will it lead to a Significant Negative effect (--) minimise loss of housing The loss of the following housing and community facilities24 : negative effects and community on community facilities?  242 residential properties likely to be required for airport expansion; The assessment is viability,  up to 165 residential properties could be required for surface access, based on a schematic including since they fall within the potential buffer zone for construction works; layout for Iteration 3 - Figure 2, publically housing,  potential secondary impacts of relocated households on existing The A4 diversion causes loss of community available mapping and facilities and communities; indirect effects. facilities including Heathrow Special Needs There is an increase sources of information  loss of industrial/employment land; Centre and potential loss of land at the Little in the community regarding the location  loss of three pubs during construction; Brook Nursery. facilities and of community facilities. No further assessment  noise implications for Pippins Primary School; industrial/ is proposed, because The A4 diversion and alterations to the M25 at employment land lost. There is a potential that no change to the  part of the Colne Valley Regional Park; Junction 14 and A3044 connection to Terminal all facilities affected by overall significance is  other formal and informal recreation sites; 5/6 are not expected to result in any additional The significance of Iteration 3 have not expected.  public rights of way; loss of housing beyond those affected by the effects is not been identified within a AC’s surface access arrangements for LHR- expected to change. desk-study. However,  cycle routes; ENR. given the scale of the  severance of section of the Colne Valley Way running from Colnbrook to overall impacts Horton; expected this is unlikely  severance of Poyle Road, which currently links Poyle and Colnbrook with to affect the outcome of Wraysbury and Horton; and the assessment.  severance of route to Poyle from the west along Bath Road. Mitigation has been recommended. 2. Will it lead to Minor Negative effect (-) The effects of Iteration increasing High demand scenarios indicate up to 60,600 new homes may be required up 3 on overall demand for to 2030. employment, housing and particularly during the community Up to 450 homes would be required per local authority per year. construction phase, and facilities? Additional spaces in local schools are likely to be required and two additional consequently on No further assessment GPs and two primary care centres per local authority to 203025. No increase in demand for housing and housing demand and The significance of is proposed, because community facilities are anticipated, as the community facilities There is also likely to be a need for additional parks or open spaces. effects is not no change to the surface access proposals are not considered to have not been expected to change. overall significance is be the main source of demand. quantified. However, it expected. is reasonable to assume that these are a small proportion of the workers required to construct the airport as a whole.

3. Will there be Significant Negative effect (--) Traffic Management: The A4 diversion and Iteration 3 would have The assessment is indirect effects Traffic movements- may lead to more traffic and increased journey times. alterations to the M25 at Junction 14 and A3044 mixed effects on based on the on community This may lead to issues of severance, loss of sense of place, breakdown in connection to Terminal 5/6 have the potential to community viability. conclusions presented No further assessment viability? community cohesion, and a reduction in the quality of amenity within the improve traffic movements, and reduce journey There may be in other topics is proposed, because community times. The A4 diversion has the potential to reductions in adverse considered within this increase severance, and load to a reduction in no change to the Air Quality- 100,392 people will experience a rise in annual mean NO2 air quality effects, assessment. The the quality of amenity during operation. overall significance is 26 although the overall conclusions presented levels. No exceedances of UK air quality objectives are anticipated . expected. Air Quality: has the potential to reduce significance of effects within these other Noise – There is a predicted increase of 27,200 people exposed to airspace congestion, particularly where a delay in is not expected to topics are based on noise exceeding 54dB LAeq16hr by 2030, which reduces steadily over time until compliance with EU Limit Values has been change. their own assumptions. an overall (beneficial) reduction in population exposure to levels >54 dB identified to the north of Heathrow in the AC’s

24 Airports Commission, 2014. Community: Impact Assessment, pp. 9-10. [online] Accessed 24/12/2015. 25 Airports Commission, 2014. Local Economy Impacts: Assessment. [online] Accessed 24/12/2015. 26 Airports Commission, 2015. Quality of Life: Equalities Impacts Report. [online] Accessed 24/12/2015.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A)

LAeq,16hr of 18,200 people is expected by 2050. Exposure to noise >63 dB surface access arrangements. LAeq,16hr is expected to increase by 41,600 in 2030, reducing to 22,400 by Noise: The diversion of the A4 would create a 2050.Strategic Development- No allocated housing sites will be lost as a new source of noise for residents in result of airport expansion, however housing allocations to the east and west Harmondsworth and Sipson. Overall noise of Heathrow will be subject to noise effects, particularly around Windsor. effects associated with the A4 diversion and Undeveloped land in the areas surrounding Heathrow is highly constrained by alterations to the M25 at Junction 14 and A3044 the London Green Belt and other designations. Increases in noise effects connection to Terminal 5/6 are not expected to may act as an additional constraint to current housing allocations or to future increase relative to the noise effects generated housing proposals, restricting the ability of the affected local authorities to by the AC’s surface access arrangements for meet housing delivery targets. LHR-ENR. Strategic Development: No additional allocated housing or employment sites would be lost, beyond those lost in the AC’s surface access arrangements for LHR-ENR. 2. To avoid or 4. Will it minimise Minor negative effect (-) The A4 diversion would lead to a potential The diversion of the minimise disproportionate With the loss and relocation of housing and community facilities such as increase in the loss of community facilities, A4 may have a disproportionate negative effects primary schools, community centres, nurseries, recreational ground and including the Heathrow Special Needs Centre disproportionate effect impacts on any on particular transport links, disproportionate effects may be experienced by vulnerable and potential loss of land at the Little Brook on particular regions, social group. regions, users social groups within the area. Furthermore, indirect effects due to increased Nursery. users or vulnerable or vulnerable traffic, reduced air quality and increased noise effects may be experienced The diversion of the A4 would create a new social groups. There social groups? source of noise for residents in Harmondsworth would be an increase disproportionately by such groups. The assessment is and Sipson. Overall noise effects associated the loss of community No further assessment based on a schematic There are higher than average BAME communities around the airport, with a with the A4 diversion and alterations to the M25 facilities, in particular is proposed, because layout for Iteration 3 - particularly high proportion of BAME populations in the local authority areas at Junction 14 and A3044 connection to for disabled people no change to the Figure 2, and on surrounding Heathrow. There is potential for BAME groups to therefore Terminal 5/6 are not expected to increase and children. overall significance is publically available experience disproportionate effects. relative to the noise effects generated by the expected. sources of information. AC’s surface access arrangements for LHR- There would be ENR. reduced adverse air Has the potential to reduce congestion, quality effects. particularly where a delay in compliance with EU Limit Values has been identified to the north of The significance of Heathrow in the AC’s surface access effects is not arrangements; expected to change. Quality of 3. To maintain and 5. Will it help to Traffic Volume Traffic Volume: The A4 diversion would lead to Life where possible maintain and Significant disruption to road users and severance of small local communities an increase in severance during operation and improve the improve quality will be experienced during the construction phase of the scheme, causing disruption for road users during construction. quality of life for of life? distress and anxiety to residents. The alterations to the M25 at Junction 14 and local residents A3044 connection to Terminal 5/6 would not The diversion of the During the operational period of the scheme, improved infrastructure and and the wider increase disruption to road users or severance. A4 and the access to public transport may provide improvements to QoL in the short population. Housing and Communities: The A4 diversion, arrangement of the term, however these are expected to be negated by long term increasing alterations to the M25 at Junction 14, and A3044 M25 junction are demand for infrastructure. expected to increase connection to Terminal 5/6 are not expected to The assessment is Housing and Communities the construction and result in any additional loss of housing. based on the operational impacts. Loss of housing/ forced moves will cause distress and have significant Employment: beneficial employment effects are conclusions presented However, these are No further assessment adverse impacts upon wellbeing. Social isolation likely to increase during anticipated during construction of the A4 in other topics not expected to is proposed, because construction from loss of community facilities, resulting in a reduction in the diversion. considered within this generate a significant no change to the QoL of those directly affected by relocation or disruption during the Noise: The A4 diversion would create a new assessment. The change in the overall significance is construction period. source of noise for residents in Harmondsworth conclusions presented environmental effects expected. New housing and community facilities will provide greater opportunities for and Sipson. However, aviation would be the within these other which would reduce leisure. main source of noise from LHR-ENR. topics are based on or improve Quality of Air quality: has the potential to reduce their own assumptions. Employment and the Economy congestion, particularly where a delay in Life. New employment and business from an expanded airport will be of significant compliance with EU Limit Values has been benefit to QoL locally and nationally from enhanced local and national identified to the north of Heathrow in the AC’s The significance of economic growth. surface access arrangements; effects is not Noise Access to Nature and Cultural Heritage: The expected to change. diversion of the A4 would cross areas which are Local exposure to construction noise and vibration can cause annoyance, for designated as being sensitive for nature the duration of works. conservation reasons, particularly in the Colne Increases in significant community annoyance due to aircraft noise exposure. Valley west of Harmondsworth.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) Increases in effects which would lead to negative health outcomes. Flooding: The changes to the surface access Reductions in night-time noise-related sleep disturbance. Reduced loss of arrangements are not expected to result in a sleep could lower anxiety and hypertension. change to flood risk which would affect quality of General increases in noise exposure of schools, which can delay reading life. development. Air Quality Poor air quality has a direct impact upon sensitive receptors, exacerbates symptoms surrounding cardiovascular and impaired lung functions and has strong dose-response relations with increased morbidity and mortality. Access to nature and cultural heritage Negative impact on the wellbeing of users of high value recreational areas including the Colne Valley Regional Park, and local residents who value the presence of such amenity areas. Indirect overall benefit to wellbeing through improving access to nature and the living environment, through mitigation and improvement measures, involving compensation of habitat and displacement of recreational areas. Flooding Direct potential negative impact upon wellbeing during construction and operation as a consequence of potential and perceived increase in flood risk. It is acknowledged that detailed design at the next stage will identify opportunities to mitigate flood risk. Economy 4. To maximise 6. Will it enhance Significant Positive effect (++) economic economic Direct impacts: The impacts which are benefits and to growth? considered within this support the The total benefits (excluding trade and producer impacts) are valued at topic are considered at competitiveness £ 57.2bn and include: a national scale, rather of the UK  Lower fares: £54.4bn; than a local scape. In addition, the sources of economy.  Frequency benefits: £2.6bn; and economic benefits are The diversion of the A4, alterations to the M25 at  Reduced delays: £0.1bn. business and airport No further assessment Junction 14 and A3044 connection to Terminal Other direct benefits are as follows: The significance of service provision is proposed, because 5/6 are not expected to result in change to effects is not based, rather than no change to the  Total producer impact: £ -46.4bn; and economic benefits to growth in addition to those expected to change. relating to local overall significance is in the AC’s surface access arrangements for  Government revenue: £2.9bn. accessibility expected. LHR-ENR. Wider economic impacts: enhancements. As a  Business output benefits: £1.1bn; and consequence, it is assumed that there is  Tax wedge: £0.5bn to 1.7bn. no change to economic The trade benefits have been estimated at either £7.5bn, £14.3bn or growth as a result of £106.6bn depending on the approach taken. However, it should be noted that change to surface these are not additive to the other wider economic impacts. access. Total benefits (excluding trade and producer impacts): £61.7 – 62.8bn 7. Will it contribute Significant Positive effect (++) The number and to sustainable Although there will be local impacts, the extent of employment impacts at a phasing of jobs created growth in national level remains unclear (due to displacement). through construction of employment? individual surface It is also anticipated that many jobs will be created during the construction The construction of the A4 diversion, alterations access schemes has No further assessment phase, although these may again be displaced from other potential to the M25 at Junction 14 and A3044 connection The significance of not been quantified. It is is proposed, because to Terminal 5/6 may result in a small increase in construction activities. effects is not reasonable to assume no change to the employment associated with construction expected to change. these would be similar overall significance is activities to those in the AC’s surface access to other road schemes expected. arrangements for LHR-ENR. and are unlikely to significantly affect the outcome of the assessment.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) 8. Will it support Significant Positive effect (++) The impacts which are the Three types of wider productivity-related impacts are estimated: considered within this competitiveness topic are considered at of the UK  enhanced productivity through increased trade and associated spin-off a national scale, rather economy? benefits; than a local scape. In  Change in tax revenue due to relocation of employment to areas with addition, the sources of different levels of productivity; and economic benefits are business and airport No further assessment  Increased business output. The diversion of the A4, alterations to the M25 at The significance of service provision is proposed, because Junction 14 and A3044 connection to Terminal effects is not based, rather than no change to the 5/6 are not expected to change competitiveness expected to change. relating to local overall significance is of the UK economy. accessibility expected. enhancements. As a consequence, it is assumed that there is no change to competitiveness as a result of change to surface access. 5. To promote 9. Will it Neutral (0) The diversion of the A4, alterations to the M25 at employment incorporate Long term increases in surface passengers associated with the airport are Junction 14 and A3044 connection to Terminal and economic accessibility anticipated. In addition, there are also expected to be increases in the use of 5/6 would improve the functioning of the surface growth in the improvements, access arrangements in the short term. surface access systems by additional users not associated with the airport. No further assessment local area and particularly with However, similar to the AC’s surface access The significance of is proposed, because surrounding key local Under the do minimum scenario, the planned improvements to the local arrangements for LHR-ENR benefits to transport network, particularly rail, will improve connectivity for those who live effects is not no change to the region. employment accessibility are expected to be negated by long 27 expected to change. overall significance is centres and and work near these routes. However, long term increases in airport and term increases in demand for surface access expected. areas of high non-airport related transport demand are expected to negate any network transport systems, including the road network. benefits to journey times for other users of surface transport systems around unemployment? Further improvements would be required to the airport. Further enhancements to the surface transport network may be ensure accessibility benefits are sustained in the required to ensure accessibility benefits are maintained in the long term. long term. 10. Will it contribute Significant Positive effect (++) The number and to growth in the The DfT has developed a range of local employment estimates following from phasing of jobs created local economy? the AC’s original estimates. These indicate that between 48,000and 97,000 through construction of additional local jobs would be generated by 2030 with between 31,000 and individual surface 28 There is potential for the diversion of the A4 to access schemes has 63,000 generated by 2050 . No further assessment contribute to the growth of the local economy in not been calculated at The quantity and distribution of high skilled jobs has not been determined at The significance of is proposed, because the surround area, including potential for a small this stage of this stage of the assessment. effects is not no change to the increase in overall construction employment assessment. However, expected to change. overall significance is It is considered likely that airport expansion will serve as a catalyst to compared the AC’s surface access assuming these are expected. business investment in the surrounding area, continuing to attract high value arrangements for LHR-ENR. similar to other road firms29. schemes these are Employment and business which develops, or is maintained by the expansion unlikely to significantly of the airport will benefit the local economy and enhance local economic affect the outcome of growth. the assessment. Noise 6. To minimise 11. Will it avoid or Predominant Significant Negative effects (--) The diversion of the A4 has the potential to The predominant and where reduce the source of noise is No further assessment Construction phase impacts are likely to be negative, with potential for generate an increase in local traffic noise Aircraft and airport possible reduce harmful effects from aviation. is proposed, because significance at sensitive receptors near to the runway extension or along experienced by neighbouring communities, operational noise is the noise impacts due to exposure no change to the construction routes. The effects cannot yet be assessed in detail but as a including Harmondsworth and Sipson, although predominant sources of on human of people and The significance of overall significance is worst case estimate can be considered as potentially Significant Negative (-- the predominant source of noise would be from noise. receptors. sensitive ). aviation. effects is not expected. The alterations to the M25 at Junction 14 and expected to change.

27 Jacobs, 2014. Local Economy Impacts: Assessment, p. 96. [online] Accessed 24/12/2015. 28 Department for Transport, 2017. Airport Capacity in the South East: Updated Appraisal Report 29 Jacobs, 2014. Local Economy Impacts: Assessment, p. 54. [online] Accessed 24/12/2015.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) buildings to The effects of changes in airspace noise exposure on the local population A3044 connection to Terminal 5/6 remain similar noise? from the LHR-ENR scheme are considered to be predominantly Significant in location to the AC’s surface access Negative (--). arrangements for LHR-ENR, so are unlikely to The effects of changes in airspace noise exposure on local NSBs from the increase noise effects. LHR-ENR scheme are considered to be predominantly Significant Negative (- -). The local effects of ground noise from the LHR-ENR scheme are considered to be Positive (+). The overall effects of the LHR-ENR scheme on the health outcomes assessed are considered to be predominantly Significant Negative (--), since it would result in increases in DALYs lost compared with the Do minimum. The local effects of airspace noise from the LHR-ENR scheme on children’s cognitive development are considered to be predominantly Significant Negative (--). The national effects of the LHR-ENR scheme are considered to be Significant Negative (--). Biodiversity 7. To protect and 12. Will it affect Significant Negative effect (--) enhance internationally, International Sites: designated nationally and sites for nature locally SWLW SPA / Ramsar conservation. designated Significant adverse effects have been identified with regard to; land take; biodiversity construction disturbance; operation disturbance including flights; hydrological sites? impacts; air quality changes; disturbance through increased levels of bird scaring/control as part of birdstrike risk management measures. Windsor Forest and Great Park SAC Burnham Beeches SAC Thursley, Ash, Pirbright and Chobham SAC Thames Basin Heaths SPA A4 diversion likely to cause the loss of priority Richmond Park SAC deciduous woodland and traditional orchards Wimbledon Common SAC habitat to the west of Harmondsworth. A4 diversion likely to cause the loss of part of the Significant adverse effects have been identified with regard to air quality The assessment has Colne Valley which is identified within the impacts associated with increased traffic flow, and direct and indirect impacts been completed Hillingdon Local Plan Policies map as a Nature upon supporting habitat as a result of the surface access strategy. through the Conservation Sites of Metropolitan or Borough No further assessment National Sites identification of Grade I Importance. The significance of is proposed, because designated biodiversity Staines Moor SSSI, A4 diversion and M25 junction arrangement effects is not no change to the sites via publically Wraysbury Reservoir SSSI would cross the Colne River, Wraysbury River expected to change. overall significance is available mapping and other watercourses. expected. Wraysbury No.1 Gravel Pit SSSI sources and a The alterations to the M25 at Junction 14 may schematic layout for Wraysbury and Hythe End Gravel Pits SSSI increase the area of land lost from the Staines Iteration 3 - Figure 2. Kempton Park Reservoirs SSSI Moor SSSI when compared to the AC’s surface Potential impacts principally associated with air and water quality changes access arrangements for LHR-ENR. that could result in adverse effects to the habitats and species interest No effects on any other sites designated for features of these sites. nature conservation. Local Sites Arthur Jacob LNR, East Poyle Meadows SNCI, Greenham's Fishing Pond SINC, Lower Colne Sites of Metropolitan Importance for Nature Conservation (SMINC), River Colne. Potential impacts from direct land take due to surface access requirements.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) 8. To conserve 13. Will it conserve Significant Negative effect (--) and enhance and enhance Habitats undesignated undesignated habitats, habitats, deciduous woodland, species, internationally traditional orchard, The assessment has valuable and nationally rivers and brooks, been completed ecological protected reedbeds and through the networks and species and A4 diversion likely to cause the loss of priority identification of habitats ecosystem valuable lowland meadows. deciduous woodland and traditional orchards via publically available functionality. ecological Species habitat to the west of Harmondsworth. mapping sources and a networks, such There are birdstrike management issues for LHR-ENR associated with the A4 diversion likely to cause the loss of part of the schematic layout for as priority Colne Valley which is identified within the Iteration 3 - Figure 2. nearby complex of open water bodies. The closer proximity of the runway and No further assessment habitats and Hillingdon Local Plan Policies map as a Nature Site visits or surveys increased air traffic is likely to result in an increased strike risk, and a The significance of is proposed, because priority species. Conservation Sites of Metropolitan or Borough have not been corresponding requirement for an increase in bird management and control effects is not no change to the Grade I Importance. undertaken in the area, activities is anticipated. expected to change. overall significance is A4 diversion and alterations to the M25 at so the actual presence Methods of deterring/scaring and controlling bird species potentially expected. Junction 14 would cross the Colne River, or absence of certain hazardous to aviation operations could potentially have an adverse effect on Wraysbury River and other watercourses. species is unknown. non-target species and biodiversity including those not listed on the It is considered likely that the area would support designation interest features. a range of species protected under UK (and EU) Given the scale of the A range of protected species including, bats, otter, water vole, reptiles wildlife legislation. overall impacts (including grass snake and slow worm), and various species of birds within expected this is unlikely 2km of the scheme boundary have been identified. It is considered feasible to affect the outcome of that the area would support a range of other species protected under UK (and the assessment. EU) wildlife legislation including but not limited to dormice, and great crested newts. Potential impacts including, loss, disturbance, habitat severance/fragmentation, air and water quality changes, mortality. 14. Will it increase Assessment significance: Significant Negative effect (--) the exposure of International Sites: wildlife to transport noise, SWLW SPA/Ramsar air pollution, Windsor Forest and Great Park SAC and water Burnham Beeches SAC pollution? Thursley, Ash, Pirbright and Chobham SAC Thames Basin Heaths SPA Richmond Park SAC Wimbledon Common SAC The assessment has Significant adverse effects have been identified with regard to disturbance, air Impacts due to exposure of wildlife include been completed using quality impacts associated with increased traffic flow, and direct and indirect disturbance, habitat severance/fragmentation, air publically available impacts upon supporting habitat as a result of the surface access strategy. and water quality changes and mortality these mapping sources and a No further assessment National Sites may arise due to the alterations to the M25 at The significance of schematic layout for is proposed, because Junction 14 and to the diversion of the A4. effects is not Iteration 3 - Figure 2. no change to the Staines Moor SSSI, The alterations to the M25 at Junction 14 may expected to change. Given the scale of the overall significance is Wraysbury Reservoir SSSI, increase the area of land lost from the Staines overall impacts expected. Wraysbury No.1 Gravel Pit SSSI, Moor SSSI when compared to the AC’s surface expected this is unlikely access arrangements for LHR-ENR. to affect the outcome of Wraysbury and Hythe End Gravel Pits SSSI, the assessment. Kempton Park Reservoirs SSSI Potential impacts principally associated with air and water quality changes that could result in adverse effects to the habitats and species interest features of these sites. Local Sites Arthur Jacob LNR, East Poyle Meadows SNCI, Greenham's Fishing Pond SINC, Lower Colne SMINC,

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) River Colne. Potential impacts from direct land take due to surface access requirements Habitats deciduous woodland, traditional orchard, rivers and brooks, reedbeds and lowland meadows. Species A range of protected species including, bats, otter, water vole, reptiles (including grass snake and slow worm), and various species of birds within 2km of the scheme boundary have been identified. It is considered feasible that the area would support a range of other species protected under UK (and EU) wildlife legislation including but not limited to dormice, and great crested newts. Potential impacts including, disturbance, habitat severance/fragmentation, air and water quality changes, mortality. Soil 9. To protect sites 15. Will it preserve, Neutral effect The assessment has designated for protect and A review of sites which are designated for geodiversity reasons, including been completed geodiversity. improve geological SSSIs and RIGS has been undertaken. No Geological SSSIs or through the geodiversity? RIGS were identified within this radius. No impacts on geodiversity are identification via publically available anticipated. No further assessment mapping sources and a The significance of is proposed, because No effects on sites of Geological conservation schematic layout for effects is not no change to the interest (SSSI or RIGS) Iteration 3 - Figure 2. expected to change. overall significance is

expected. Given the scale of the overall impacts expected this is unlikely to affect the outcome of the assessment. 10. To minimise loss 16. Will it maximise Significant Negative effect (--) The assessment has of undeveloped construction on This scheme entails land take of 336 ha, with a further 330 ha potentially been completed soils and of previously affected by surface access and 57 ha identified for flood storage. through the Best and Most developed land, There would be an increase in land take around identification via Versatile minimise use of The site area of the airport incorporates approximately 371ha of agricultural M25 Junction 14, and due to the diversion of the publically available land, a significant proportion of which is likely to be BMV agricultural land. No further assessment agricultural greenfield land? A4, but also a decrease in land take as the mapping sources and a The significance of is proposed, because land, and Agricultural land is a finite and irreplaceable resource, and although A3044 diversion to Junction 13 considered as schematic layout for compensation will be provided to land owners, the loss of the land cannot be effects is not no change to the protect soil part of the AC's surface access arrangements Iteration 3 - Figure 2. expected to change. overall significance is against erosion, mitigated. would not be required. The land take areas expected. contamination As a consequence of the site location, a high proportion of the land take potentially include areas of Best and Most Given the scale of the and required is from agricultural land, the quantity of PDL should be considered a Versatile agricultural land. overall impacts degradation. correspondingly small proportion. expected this is unlikely to affect the outcome of the assessment. 17. Will it lead to the Negative effect (-) The diversion of the A4 takes place in an area The assessment has disturbing, which is currently undeveloped. The alterations Development may result in soil loss or burial, physical damage including been completed harm, to the M25 at Junction 14 and A3044 connection compaction, sealing, and structural damage, changes to soil water regime, through information via contamination to Terminal 5/6 at the roads affected remain effects on organic matter and soil stripping and storage. In addition, publically available No further assessment or loss of soil similar in land take area to the AC’s surface development has the potential to result in contamination of soil, resulting in The significance of mapping sources and is proposed, because resources? access arrangements for LHR-ENR. There risks to human health or the environment. effects is not schematic information no change to the would be a smaller increase in land take around expected to change. on Iteration 3. overall significance is The use of large areas of previously undeveloped land will affect the quality Junction 14, but a larger decrease in land take, expected. of soil and land resources meaning these areas of land will no longer be as the A3044 diversion to Junction 13 Given the scale of the suitable for other uses, including farming. considered as part of the AC's surface access overall impacts arrangements would not be required. These are expected this is unlikely not expected to result in a change to the impacts

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) on soil resources, including due to increased to affect the outcome of potential for contamination. the assessment.

Water 11. To protect the 18. Will proposals Negative effect (-) quality of have adverse Physical impacts are considered in question 19 below. Water quality impacts surface and effects on the arising from polluted runoff during construction and operation. ground waters, achievement of and use water the A further risk during construction is posed by the historic landfill within the resources environmental proposed development footprint, posing a risk if contaminants are mobilised. sustainably. objectives Two of the WFD water bodies in the study area are classified as having a established ‘Failing’ chemical status, so a potential increase in pollutants could have a under the Water more magnified impact on these water bodies. Framework A number of measures would be considered to improve water quality. The assessment has Directive? Surface water quality monitoring would be undertaken in key risk construction been completed areas in close proximity to surface watercourses and boreholes will be through the installed. identification of the areas surrounding A Sustainable Drainage Strategy will include dedicated areas for de-icing watercourses via No further assessment aircraft and a glycol recovery procedure to reduce the concentration of glycol publically available No changes to the effects assessed as being The significance of is proposed, because within surface water runoff and separate storage tanks for ‘clean’ and ‘first mapping sources and associated with the AC's Surface Access effects is not no change to the flush’ surface water. schematic layout of arrangements. expected to change. overall significance is Possible addition of a new STW with some of the treated water to be re-used Iteration 3. expected. for non-potable purposes within the airport. Re-use of surface water would be maximised, including rainwater harvesting, Given the scale of the which will be installed. overall impacts expected this is unlikely There is potential for hydrological conditions to be altered on Staines Moor to affect the outcome of SSSI from diversion of the River Colne and this would need to be addressed the assessment. during detailed design. There would also be works directly adjacent to King George VI Reservoir, which forms part of Staines Moor SSSI and South West London Waterbodies Special Protection Area (SWLW SPA) and nearby Wraysbury Reservoir (also part of the SWLW SPA). This could have negative effects, depending on design (also see Appendix A.5). There are a number of reservoirs and gravel pits which make up the SWLW SPA further downstream from the Airport, (see Appendix A.5 for effects on site integrity). 19. Will it result in Significant Negative effect (--) the modification Approximately 12km of existing watercourse would be replaced with The A4 diversion would increase the of requirement for culverting of watercourses diverted/realigned channels and culverts. The diversions of the Colne Brook The assessment has connecting the Colne River. watercourses? and Poyle Channel (approx. 5km) around the west end of an extended north been completed

runway would be technically difficult and are likely to have effects on the through the The M25 junction 14 would require culverting of hydromorphology/ geomorphology due to the changed gradients and other identification of watercourses including the Colne River and associated uncertainties. watercourses via Wraysbury River, however this would not be a publically available No further assessment An initial estimate suggests there could be in excess of 12km of additional material increase beyond the AC's surface The significance of mapping sources and is proposed, because culverts. The Longford River, the Duke of Northumberland’s River, River access arrangements for LHR-ENR . effects is not schematic layout of no change to the Colne and Wraysbury River would be culverted underneath the proposed expected to change. Iteration 3. overall significance is runway. The alterations to the M25 at Junction 14 and expected. Water bodies are sensitive and extensive diversions/culverting would A3044 connection to Terminal 5/6 will remove Given the scale of the counteract improvements to waterbodies, including environmentally friendly the need for the diversion of the A3044 to run overall impacts flood schemes (as part of the Lower Colne Catchment flood scheme) parallel with the M25 south west of the airport in expected this is unlikely maintaining open channels for Heathrow Terminal 5. The WFD strongly the AC's surface access arrangements for LHR- to affect the outcome of discourages culverting due to the detrimental impacts on the overall ENR. This would decrease the need for the assessment. environment both that of the waterbody and the surrounding area. There are culverting in the area adjacent to the Wraysbury also significant cumulative impacts from culverting on the biodiversity, soils River. and landscape.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) Changes to the sedimentation processes can lead to deterioration in water quality and could impact the waterbody status should the sediment contain contaminants.

20. Will it result in Significant Negative effect (--) The A4 diversion would increase the the loss in Diversion of Colne Brook and Poyle Channel and culverting of the Longford requirement for culverting of watercourses productivity of River, the Duke of Northumberland’s River, River Colne and Wraysbury River connecting the Colne River. The assessment has fisheries? may affect the hydromorphology/geomorphology which may cause a been completed deterioration of the ecological status, potentially affecting productivity of The M25 junction 14 would require culverting of through the fisheries. watercourses including the Colne River and identification of Wraysbury River, however this would not be a watercourses via Construction of approximately 12km of culvert as part of the scheme would material increase beyond the AC's surface publically available No further assessment have negative impacts on fisheries. access arrangements for LHR-ENR. The significance of mapping sources and is proposed, because Fisheries could also be negatively impacted by residual water quality impacts effects is not schematic layout of no change to the from polluted runoff. The alterations to the M25 at Junction 14 and expected to change. Iteration 3. overall significance is A3044 connection to Terminal 5/6 will remove expected. the need for the diversion of the A3044 to run Given the scale of the parallel with the M25 south west of the airport. overall impacts This would decrease the need for culverting in expected this is unlikely the area adjacent to the Wraysbury River. to affect the outcome of the assessment. The changes to culverting are not expected to result in a change to the productivity of fisheries. 21. Will it lead to an Significant Negative effect (--) increase in the Total annual potable water demands for 2026 and 2050 are 2.62Mm³/year consumption of and 3.76 Mm³/year, respective increases of 0.32Mm³/year and 1.46 Mm³/year available water from 2013 demands. resources? A 77% increase in passenger numbers relative to 2013 has been forecast after the completion of the extended northern runway to 134.9 million per year by 2050. Rainwater harvesting is expected to account for 9% of the No further assessment additional demand. Water efficiency measures are considered able to reduce Construction may alter water consumption The significance of is proposed, because the demand by 2 to 5%. Leakage reduction measures could also save up to although the change is not likely to result in a effects is not no change to the 0.115Mm3. No figures are available for 2085 due to limitations in the forecast change relative to the AC's surface access expected to change. overall significance is figures and information within the WRMP. arrangements for LHR-ENR. expected. The scheme promoter’ submission outlines that the water demands for the Shortlisted Scheme can be feasibly met by increased abstraction from surface and/or groundwater. The Affinity Water WRMP concluded that there is a deficit in the Water Resource Zone that supplies Heathrow, in 2013 only 46% of the licensed volume was abstracted. Construction of the scheme will lead to short term increases in water demand. 12. To minimise 22. Will it increase Negative effect (-) The construction of the A4 diversion would result The assessment has flood risk and flood risk Increase in impermeable areas, without suitable mitigation, could lead to in an increase in impermeable areas. Flood risk been completed ensure through runoff rates greater than the greenfield rate resulting in increased risks of may increase as a consequence of a higher through the resilience to increased run flooding elsewhere. There are methods of reducing flood risk. runoff rate in comparison to the areas greenfield identification of the climate change. off? rate. areas Flood Risk Zone No further assessment Scheme promoter may need to update method for estimating the attenuation The alternative M25 Junction 14 arrangement is via publically available The significance of is proposed, because requirements as more appropriate methodologies are available. Despite this not expected to materially increase the quantity mapping sources and effects is not no change to the the volume is similar to estimates by Jacobs. of impermeable area. There is likely to be a the schematic layout of expected to change. overall significance is Elevated groundwater may also contribute to the surface water runoff to the decrease in the impermeable area created due Iteration 3. expected. ponds during significant rainfall events or prolonged wet periods. This may to A3044 connection to Terminal 5/6 not being Given the scale of the further reduce the attenuation volumes available. required. The Iteration 3 arrangements are not overall impacts expected to result in a material increase in flood expected this is unlikely risk when compared to the AC’s surface access to affect the outcome of arrangements for LHR-ENR. the assessment.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) 23. Will it increase Significant Negative effect (--) area of Proposed runway will extend onto the floodplains of the River Colne, development Wraysbury River and the Colne Brook, resulting in occupying floodplain areas within areas at designated as Flood Risk Zones 2 and 3. The existing fluvial flood risk to risk of flooding? Heathrow Airport is low. The A4 diversion travels through Flood Zone 2 Development is expected to lead to a loss of up to 45 ha of undefended flood west of Harmondsworth. This would increase the plain with only a 33 ha being set aside for compensation purposes. area of development within areas at risk of The A4 diversion has Assessment method has potentially led to an underestimation of the loss of flooding when compared to the AC's surface the potential to increase flood plain storage. Consequences of this flood storage loss would be direct access arrangements. risk of flooding and No further assessment increase of flood areas downstream, with the likely impact of increased risk to The M25 junction 14 arrangement travels The significance of without further is proposed, because developed areas. through Flood Zone 2 west of the existing M25, effects is not information on design it no change to the There are isolated areas within the extended footprint that are at medium or this is not expected to result in a change to the expected to change. is not possible to be overall significance is high risk of surface water flooding. area of development at risk from flooding. certain that potential expected. Heathrow Airport and the proposed new runway are located on River Terrace There would be a decrease in the area of adverse effects can be Gravels, which is classified as Primary and Secondary Aquifers. There is the development within an area of flood risk due to mitigated. potential for elevated groundwater levels and/or groundwater flooding in the A3044 connection to Terminal 5/6 not being area. required. Risk of flooding from reservoirs is considered negligible. Peak flow and rainfall is expected in increase from the baseline to 2086, meaning that developments on the floodplain and zones susceptible to groundwater flooding could be at risk from increases in rainfall intensity. 24. Will it be able to Negative effect (-) adapt to climate Without appropriate mitigation the scheme could result in increased risks to change? itself and sites elsewhere as a result of increased peak river/overland flows, runoff rates from across the scheme and altered volumes available for abstraction for water use. No further assessment Scheme promoter has applied a 20% increase in peak flows and rainfall, a The significance of is proposed, because 40% allowance will need to be assessed to be compliant with current No information is available on design for climate effects is not no change to the guidance. change. expected to change. overall significance is No consideration appears to be given to the implications of climate change on expected. the River Terrace Gravels, other than the scheme will be raised above existing ground levels, no consideration is given to the implications of raised ground levels across the wider area. The WRMP demonstrates that sufficient water is available to meet potable and non- potable requirements. Air Quality 13. To improve air 25. Will it support Significant Negative effect (--) Further qualitative quality and compliance with A reassessment of compliance3031 with the EU Air Quality Directive taking assessment was reduce local, national account the government’s 2017 Air Quality Plan indicates that LHR-ENR The diversion of the A4, alterations to the M25 at undertaken to emissions and European impacts on compliance with EU limit values. Junction 14 and A3044 connection to Terminal determine whether the consistent with air quality 5/6 may prevent the scheme from impacting on significance of effect EU, national requirements or NOx and PM2.5 emissions are projected to exceed the NECD target for 2030 would change as a – but the increase with the scheme is a very small fraction of the target. compliance with EU limit values in the vicinity of The significance of and local legislation? the airport. However, given the uncertainties the effect may change result of the variation. The maximum predicted annual mean NO2 concentration with the scheme in standards and inherent in air quality modelling, there remains a with the variation and Assessment found that place at any receptor in Principal Study Area is 37.2µg/m3 in 2030. requirements. risk of worsening exceedances of limit values further analysis was with the updated alongside individual links, most notably in central undertaken. surface access London. strategy, the scheme does not impact on The magnitude of the impact to the north of the compliance with limit runway may decrease. values in 2030. There is, however, a risk that the option will delay

30 WSP | Parsons Brinckerhoff, February 2017, Updated Air Quality Re-Analysis, published as part of the draft Airports NPS Consultation documentation 31 WSP, October 2017, 2017 Plan Update to Air Quality Re-analysis.

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) compliance with limit values and the risk increases the earlier the assumed opening year for the option. The risk is high until 2029 with the updated access strategy; very high in all years without the updated access strategy. 26. Will it reduce the Significant Negative effect (--) exposure to air There are no predicted exceedances of the air quality objective at any quality issues receptor location, in either the Do-Minimum or LHR-ENR scenarios. for local The scheme will increase exposure to pollution at 38,656 properties, of which communities 3 and sites 113 are considered ‘at risk’ (>32μg/m ). There is a risk that with opening Further qualitative earlier than 2030 that exceedances of air quality objectives could occur. assessment is required designated for The magnitude of the maximum impact to the The significance of to determine whether nature The scheme results in increased exposure to pollution over sites north of the runway may decrease, but air quality the effect is unlikely to the significance of conservation? designated for nature conservation at all 10 sites assessed, including already meets the objectives be affected. effect would change as sites where the critical level is currently exceeded and South West a result of the variation. London Waterbodies Ramsar/SPA. No exceedances of critical loads are modelled with the scheme. Increase in national emissions of NOx and PM2.5. . Carbon 14. To minimise 27. Will the Significant Negative effect (--) carbon approach to the Over the 60-year Appraisal Period (2026 to 2086), under the Carbon-Capped emissions in development be scenario, it is forecast that the development of an extended Northern runway airport consistent with at Heathrow Airport will result in the emission of a further additional further No further assessment construction overall carbon 256.1 MtCO2 over the baseline case. and operation. requirements? is proposed, because Over the same Appraisal Period under the Carbon-Traded scenario, it is Not applicable - see Question 28 below. The significance of no change to the forecast that the development of an extended Northern runway at Heathrow 2 effects is not overall significance is Airport will result in the emission of a further 266.7 MtCO over the baseline expected to change. expected. case. In both cases, construction emissions will contribute a further 10.1 MtCO2e to UK emissions, however this is a one-off impact at the beginning of the Appraisal Period. 28. Will the Significant Negative effect (--) approach Over the 60-year Appraisal Period (2026 to 2086), under the carbon-traded minimise scenario, it is forecast that the development of an extended Northern runway carbon at Heathrow Airport will result in the emission of an additional 8.1 MtCO2 due No further assessment emissions to Passenger and Staff Surface Access over the baseline case. The iteration 3 arrangements are not expected to The significance of is proposed, because associated with In the DfTs revised carbon-capped scenario demand is unaffected by the materially alter carbon emissions from the AC’s effects is not no change to the surface abatement measures implemented, so the surface access CO2 estimates are surface access arrangements for LHR-ENR. expected to change. overall significance is transportation? the same as in the carbon-traded case expected. Emissions from freight transport movements are also likely to rise, but these were not quantified in the DfT’s assessment. It is recommended that they be assessed by an applicant at the time of detailed design. Resources 15. To minimise 29. Will it be Significant Negative effect (--) The volume of The consumption of natural, non-renewable and Waste consumption of possible to Consumption of large volumes of construction material. Operational construction materials resources would occur during construction and No further assessment natural, minimise the consumption reduced by comparison with construction phase. to be consumed for particularly consumption of operation of the surface access arrangements. The significance of individual surface is proposed, because virgin non- natural It is not anticipated that Iteration 3 or Iteration 4 effects is not access arrangements no change to the renewable, resources? would significantly augment the adverse impacts expected to change. has not yet been overall significance of impact is expected. resources. arising from the AC’s core surface access determined. However, arrangements for LHR-ENR. due to the scale of the resource consumption

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) required to deliver the airport expansion, the surface access arrangements are unlikely to change the overall significance of effect. 16. To minimise the 30. Will it be Significant Negative effect (--) The volume of waste generation of possible to Generation of large volumes of construction waste that could be sent to likely to be generated waste in minimise waste landfill. for individual surface accordance generated Volumes of waste to be generated during operation are likely to be greatly access arrangements with the during has not yet been reduced by comparison with construction. No further assessment principals of the construction It is not anticipated that waste generated would determined. Forecasts for waste generation in operation are marginally lower than the The significance of is proposed, because resource and operation? contribute significantly to the volume arising from highest forecasts (LHR-NWR), across all operational scenarios. effects is not Due to the scale of the no change to the efficiency the AC’s core surface access arrangements for expected to change. impacts associated with overall significance of hierarchy. LHR-ENR. the core airport impact is expected. expansion works, waste generated by Iteration 3 or Iteration 4, is unlikely to change the overall significance of effect. Historic 17. Conserve and 31. Will it affect the Significant Negative effect (--) The diversion of the A4 could affect the setting of Environment where significance of Land take study area (including surface access corridors) Grade I, II* and a number of Grade II listed appropriate internationally buildings. In particular, these include a Grade I enhance and nationally Construction activities including the demolition or partial demolition of Listed Tithe Barn north west of Harmondsworth heritage assets designated structures will impact on 7 Grade II Listed Buildings resulting in their total or (The Great Barn), and a Grade II* Listed Church partial loss. Total loss is substantial harm. Partial loss could result in assets and the wider heritage assets (The Church of St. Mary). East of Sipson, an historic and their being put at risk. Partial loss can also result in substantial harm. offline section of the diversion of the A4 re-joins environment settings? A Conservation Area will also be affected. The significance of assets lying the current A408 adjacent to Sipson House, a outside of the land take but associated with those within it will be at risk of including Grade II Listed Building. In addition, the setting buildings, harm. of Harmondsworth Conservation Area would be The assessment has structures, affected. Intermediate Study Area been completed No further assessment landscapes, Construction and operation will impact on the setting of 2 Scheduled The significance of through information via is proposed, because townscapes There are Listed Buildings on the periphery of Monuments, 23 listed buildings (Grades II* and II) and 5 Conservation Areas. effects is not publically available no change to the and Stanwell Moor which may have views of the This will result in harm to the significance of the assets. expected to change. mapping sources and overall significance is archaeological current A3113 and M25, the proposed schematic information expected. remains. Outer study area arrangement of the M25 Junction 14 and A3044 on Iteration 3. Operation of the scheme will impact on the setting of a Scheduled Monument, connection to Terminal 5/6 is unlikely to 160 Listed Buildings (all Grades), a Registered Park and Garden and 6 generate an increase in effects relative to the Conservation Areas. This will result in harm to the significance of the assets. AC’s surface access arrangements for LHR- ENR.

No change in the effects on designated heritage sites of either international or national importance (World Heritage Site, Scheduled Monuments and Registered Parks and Gardens) is anticipated.

32. Will it affect the Significant Negative effect (--) The diversion of the A4 travels close to Sipson significance of and Harmondsworth. Data collection for non- Land take Study Area (including surface access corridors) non-designated designated heritage assets for Iteration 3 has not The assessment has heritage assets 74 assets are present. been undertaken but there are likely to be been completed No further assessment and their Total removal of any archaeological remains during construction activities increased effects on non-designated assets. An The significance of through information via is proposed, because settings? and earth-moving activities in particular. area north of Harmondsworth and also effects is not publically available no change to the The significance of non-designated remains will be subject to substantial surrounding Sipson are identified as expected to change. mapping sources and overall significance is harm. Archaeological Priority Areas, so there is schematic information expected. Intermediate Study Area potential for effects on buried archaeology. on Iteration 3. These include the site of a former Benedictine 79 assets are present. Priory west of Harmondsworth. Any impact within the intermediate study area s will be to the significance of

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) the setting of the assets. This has the potential to result in harm to the The alterations to the M25 J14 take place in an significance of the assets. area which would be developed as part of the Outer Study Area assessed design so no change is predicted. None identified. HER search does not extend into outer Study Area. Any impact within the outer area will be to the significance of the setting of the assets. This has the potential to result in harm to the significance of the assets. 33. Will it conserve Significant Negative effect (--) or enhance No beneficial impacts are presented in the ACs report. All impacts listed are heritage assets adverse. However, it is possible that following mitigation positive outcomes and the wider could be realised through some enhancement to Conservation Areas and historic community engagement and by addressing Heritage at Risk (including those No further assessment environment that become at risk as a result of the scheme), improving the setting of The significance of is proposed, because including heritage assets, together with opportunities for community engagement No beneficial impacts are known. effects is not no change to the landscapes, including improving access to and/or interpretation, understanding and expected to change. overall significance is townscapes, appreciation of heritage assets’ expected. buildings, structures, and archaeological remains? 34. Will it harm the Significant negative effect (--) The diversion of the A4 could affect the significance of There is likely to be increased light levels from construction and operational significance of Grade I, II* and a number of heritage assets, lighting in addition to any lights from aircraft whilst on the ground and in flight. Grade II listed buildings. In particular, these for example The setting of 30 designated heritage assets could be affected within 300m of include a Grade I Listed Tithe Barn north west of from the the scheme area (1 Grade II* Listed buildings 22 Grade II, two Scheduled Harmondsworth (The Great Barn), and a Grade generation of Monuments and five Conservation Areas) and from 300m to 2km the setting II* Listed Church (The Church of St. Mary). East The assessment has noise, of a further 168 designated assets could potentially be affected (four Grade I, of Sipson, an offline section of the diversion of been completed No further assessment pollutants and five Grade II* and 151 Grade II Listed Buildings, one Scheduled Monuments the A4 re-joins the current A408 adjacent to The significance of through information via is proposed, because visual intrusion? and six Conservation Areas and 1 Registered Park and Garden. Sipson House, a Grade II Listed Building. In effects is not publically available no change to the The setting of seventy-nine non-designated assets could be affected. addition, the setting of Harmondsworth expected to change. mapping sources and overall significance is Historic landscape and townscape character will be affected. Conservation Area would be affected. schematic information expected. on Iteration 3. Historic landscape and townscape character will be affected. The alterations to the M25 at Junction 14 and There is unlikely to be an impact on below-ground archaeological remains. A3044 connection to Terminal 5/6 are unlikely to Data was only available for the intermediate study area i.e. 300m of the materially change noise, pollution and visual scheme area. intrusion on heritage assets relative to the AC’s surface access arrangements for LHR-ENR. Landscape 18. To promote the 35. Will it protect Negative effect (-)National Landscape Designations: Potential indirect No additional effects on designated sites of protection and and enhance impacts of new lighting and the direction / height / number of flights over the either international, national importance are improvement of nationally and Chilterns AONB. anticipated. landscapes locally Local Landscape Designations: Long distance views from Area of townscapes, designated Landscape Importance; impacts upon the Hillingdon Lower Colne Floodplain, The diversion of the A4 west of Harmondsworth waterscapes landscape, Hillingdon Open Gravel Terrace, Slough Road Infrastructure and Hillingdon is within an area which is locally classified by the and the visual townscape and Historic Core character areas. London Borough of Hillingdon as the Lower resource, waterscape? Colne Floodplain. It is also part of the Colne The assessment has Local Townscape Designations: The loss of landscape features would be been completed including areas Valley Park. The diversion of the A4 would No further assessment of tranquillity permanent within the Hillingdon Historic Core. increase the effects on these local designations. The significance of through information via is proposed, because and dark skies. Other areas with landscape character value: Loss of the Colne Valley effects is not publically available no change to the Regional Park and views from the park at Colnbrook and Poyle would be The alterations to the M25 at Junction 14 and expected to change. mapping sources and overall significance is impacted by the construction works. A3044 connection to Terminal 5/6 would avoid schematic information expected. the requirement for a diversion of the A3044 to on Iteration 3. run parallel with the M25. This would reduce the amount of land take required within the Colne River Floodplain landscape character area between Wraysbury and King George Reservoir. The amount of land required to accommodate a roundabout for Terminal 5/6 would also reduce landtake north west of Stanwell Moor, within the

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Table 6 LHR-ENR Variation Screening Assessment: Iteration 3 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) Colne River Valley Floor Landscape Character Area. 36. Will it lead to Significant negative effect (- -) Diversion of the A4 is likely to affect views and impact on Potential for deterioration in valued views and vistas on the Chilterns AONB visual amenity for locally sensitive receptors at sensitive views Sipson and Harmondsworth during construction from the direction / height / number of flights overhead. The assessment has and their and operation. Views from properties in Stanwell, Stanwell Moor, Harmondsworth and been completed No further assessment settings? The significance of through information via is proposed, because Sipson would be impacted during construction and operation. The impact on views from properties in Stanwell, effects is not publically available no change to the Views from the Public Rights of Way south of the M4 during construction and Stanwell Moor would decrease as the alignment expected to change. mapping sources and overall significance is operation. of the M25 J14 and connection to Terminal 5/6 schematic information expected. would occupy less land north east, north, north on Iteration 3. west and west of Stanwell Moor than the previously assessed diversion of the A3044 adjacent and to the east of the M25. Negative effect (-) 37. Will it lead to a Construction and operation of the A4 diversion is loss of Potential for increased numbers of aircraft over-flying the Chilterns AONB, likely to lead to an increase in light pollution, in The assessment has tranquillity and which may reduce tranquillity levels. Potential for increased aircraft noise and particular to the west of Harmondsworth and been completed No further assessment increase in light views of aircraft in flight. east of Sipson. through information via is proposed, because pollution? There is likely to be increased light levels from construction and operational The significance of publically available no change to the lighting, in addition to any lights from aircraft whilst on the ground and in The alterations to the M25 at Junction 14 and effects is not mapping sources and overall significance is flight. A3044 connection to Terminal 5/6 are not likely expected to change. schematic information expected. Impacts would be the greatest for those receptors to the west around to materially alter tranquillity or light pollution at on Iteration 3. Colnbrook, and to the north around Harmondsworth and Sipson. Stanwell Moor.

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Table 7 LHR-ENR Variation Screening Assessment: Iteration 4 Topic Objective Appraisal Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Further Potential Change To Effects (Increase Impact/ Likely Change To Question Limitations Based On Assessment To Be Decrease Impact/ Unknown) Significance Existing Information Taken (Or N/A) Community 1. To avoid or 1. Will it lead to a Significant Negative effect (--) Traffic management on the A4 and the alterations to minimise loss of housing The loss of the following housing and community facilities32 : the M25 at Junction 14 and A3044 connection to negative effects and community Terminal 5/6 and are not expected to increase land on community facilities?  242 residential properties likely to be required for airport expansion; take from housing or community facilities beyond viability,  up to 165 residential properties could be required for surface access, those affected by the AC’s surface access including since they fall within the potential buffer zone for construction works; arrangements for LHR-ENR. housing,  potential secondary impacts of relocated households on existing facilities and communities; The assessment is based indirect effects.  loss of industrial/employment land; on a schematic layout for No further  loss of threepubs during construction; Iteration 4 - Figure 3, assessment is The significance of  noise implications for Pippins Primary School; publically available proposed, because effects is not  part of the Colne Valley Regional Park; mapping and sources of no change to the expected to change.  other formal and informal recreation sites; information regarding the overall significance is  public rights of way; location of community expected.  cycle routes; facilities.  severance of section of the Colne Valley Way running from Colnbrook to Horton;  severance of Poyle Road, which currently links Poyle and Colnbrook with Wraysbury and Horton; and  severance of route to Poyle from the west along Bath Road. Mitigation has been recommended. 2. Will it lead to Minor Negative effect (-) No increase in demand for housing and community The effects of Iteration 4 increasing High demand scenarios indicate up to 60,600 new homes may be facilities are anticipated, as the surface access on overall employment, demand for required up to 2030. arrangements are not considered to be the main particularly during the housing and Up to 400 homes would be required per local authority per year. source of demand. construction phase, and No further community Additional spaces in local schools are likely to be required and two consequently on housing assessment is facilities? additional GPs and two primary care centres per local authority to 203033. The significance of demand and community proposed, because There is also likely to be a need for additional parks or open spaces. effects is not facilities have not been no change to the expected to change. quantified. However, it is overall significance is reasonable to assume expected. that these are a small proportion of the workers required to construct the airport as a whole. 3. Will there be Significant Negative effect (--) Traffic Management: Traffic management on the A4 indirect effects Traffic movements- may lead to more traffic and increased journey and alterations to the M25 at Junction 14 and A3044 on community times. This may lead to issues of severance, loss of sense of place, connection to Terminal 5/6 are designed to improve viability? breakdown in community cohesion, and a reduction in the quality of traffic movements, and reduce journey times. Iteration 4 would have amenity within the community Air Quality: Traffic management on the A4 and mixed effects on Air Quality- 100,392 people will experience a rise in annual mean NO2 alterations to the M25 at Junction 14 and A3044 community viability. The assessment is based levels. No exceedances of UK air quality objectives are anticipated34. connection to Terminal 5/6 would reduce It is anticipated that on the conclusions No further Noise – There is a predicted increase of 27,200 people exposed to congestion, and may result in a shorter delay to traffic management presented in other topics assessment is airspace noise exceeding 54dB LAeq 16hr by 2030, which reduces steadily compliance with Air Quality Directive Limit Values in alone is not likely to considered within this proposed, because over time until an overall (beneficial) reduction in population exposure to the Greater London Urban Area reduce the future assessment. The no change to the levels >54 dB LAeq,16hr of 18,200 people is expected by 2050. Exposure to Noise: Traffic management on the A4 and potential air quality conclusions presented overall significance is noise >63 dB LAeq,16hr is expected to increase by 41,600 in 2030, reducing alterations to the M25 at Junction 14 and A3044 exceedances. within these other topics expected. to 22,400 by 2050. connection to Terminal 5/6 are not expected to alter are based on their own Strategic Development- No allocated housing sites will be lost as a the significance of the noise effects, which would The significance of assumptions. result of airport expansion, however housing allocations to the east and primarily be generated by aircraft movements. effects is not west of Heathrow will be subject to noise effects, particularly around Strategic Development: No additional allocated expected to change. Windsor. Undeveloped land in the areas surrounding Heathrow is highly housing or employment sites would be lost, beyond constrained by the London Green Belt and other designations. Increases those lost in the AC’s surface access arrangements in noise effects may act as an additional constraint to current housing for LHR-ENR.

32 Airports Commission, 2014. Community: Impact Assessment, pp. 9-10. [online] Accessed 24/12/2015. 33 Airports Commission, 2014. Local Economy Impacts: Assessment. [online] Accessed 24/12/2015. 34 Airports Commission, 2015. Quality of Life: Equalities Impacts Report. [online] Accessed 24/12/2015.

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allocations or to future housing proposals, restricting the ability of the affected local authorities to meet housing delivery targets. 2. To avoid or 4. Will it minimise Minor negative effect (-) No increase in land take, loss of community facilities The diversion of the minimise disproportionate With the loss and relocation of housing and community facilities such as or housing is anticipated. A4 and alterations to disproportionate negative effects primary schools, community centres, nurseries, recreational ground and Noise effects associated with traffic management on the M25 at Junction impacts on any on particular transport links, disproportionate effects may be experienced by vulnerable the A4 and alterations to the M25 at Junction 14 and 14 and A3044 social group. regions, users social groups within the area. Furthermore, indirect effects due to A3044 connection to Terminal 5/6 are not expected connection to or vulnerable increased traffic, reduced air quality and increased noise effects may be to increase relative to the noise effects generated by Terminal 5/6 are not social groups? experienced disproportionately by such groups. the AC’s surface access arrangements for LHR- expected to have a The assessment is based No further There are higher than average BAME communities around the airport, ENR. disproportionate effect on the route options assessment is with a particularly high proportion of BAME populations in the local Traffic management on the A4 and alterations to the on particular regions, which have been proposed, because authority areas surrounding Heathrow. There is potential for BAME M25 at Junction 14 and A3044 connection to users or vulnerable proposed, and on no change to the groups to therefore experience disproportionate effects. Terminal 5/6 may improve traffic congestion and social groups. publically available overall significance is reduce potential air quality effects where future sources of information. expected. potential exceedances have been identified to the There would be north of Heathrow in the AC’s surface access reduced adverse air arrangements for LHR-ENR. quality effects.

The significance of effects is not expected to change. Quality of 3. To maintain and 5. Will it help to Traffic Volume Traffic Volume: Traffic management on the A4 and Life where possible maintain and Significant disruption to road users and severance of small local alterations to the M25 at Junction 14 and A3044 improve the improve quality communities will be experienced during the construction phase of the connection to Terminal 5/6 has potential to reduce quality of life for of life? scheme, causing distress and anxiety to residents. the disruption to road users or severance during local residents During the operational period of the scheme, improved infrastructure and operation. and the wider access to public transport may provide improvements to QoL in the short Housing and Communities: The A4 traffic population. term, however these are expected to be negated by long term increasing management and alterations to the M25 at Junction demand for infrastructure. 14 and A3044 connection to Terminal 5/6 would not Housing and Communities increase the loss of housing. Loss of housing/ forced moves will cause distress and have significant Employment: There are unlikely to any operational adverse impacts upon wellbeing. Social isolation likely to increase during changes to employment as a result of Traffic construction from loss of community facilities, resulting in a reduction in management on the A4 and alterations to the M25 the QoL of those directly affected by relocation or disruption during the at Junction 14 and A3044 connection to Terminal construction period. 5/6. Beneficial employment effects are anticipated New housing and community facilities will provide greater opportunities for during construction of the A4 traffic management. leisure. Noise: Traffic management on the A4 and Employment and the Economy alterations to the M25 at Junction 14 and A3044 New employment and business from an expanded airport will be of connection to Terminal 5/6 are not expected to significant benefit to QoL locally and nationally from enhanced local and increase noise effects, which will primarily be Iteration 4 would have The assessment is based national economic growth. generated by aircraft movements. mixed effects on on the conclusions Noise Air quality: Traffic management on A4 and community viability. No further presented in other topics Local exposure to construction noise and vibration can cause annoyance, alterations to the M25 at Junction 14 and A3044 There may be assessment is considered within this for the duration of works. connection to Terminal 5/6 would reduce reductions in adverse proposed, because assessment. The Increases in significant community annoyance due to aircraft noise congestion, and may result in a shorter delay to air quality effects, no change to the conclusions presented exposure. compliance with Air Quality Directive Limit Values in although the overall overall significance is within these other topics Increases in effects which would lead to negative health outcomes. the Greater London Urban Area significance of effects expected. are based on their own Reductions in night-time noise-related sleep disturbance. Reduced loss of Access to Nature and Cultural Heritage: Traffic is not expected to assumptions. sleep could lower anxiety and hypertension. management on A4 and alterations to the M25 at change. General increases in noise exposure of schools, which can delay reading Junction 14 and A3044 connection to Terminal 5/6 development. are not expected to decrease access to nature and Air Quality cultural heritage. Poor air quality has a direct impact upon sensitive receptors, exacerbates Flooding: The changes to the surface access symptoms surrounding cardiovascular and impaired lung functions and arrangements are not expected to result in a has strong dose-response relations with increased morbidity and significant change to flood risk which would affect mortality. quality of life. Access to nature and cultural heritage Negative impact on the wellbeing of users of high value recreational areas including the Colne Valley Regional Park, and local residents who value the presence of such amenity areas. Indirect overall benefit to wellbeing through improving access to nature and the living environment, through mitigation and improvement measures, involving compensation of habitat and displacement of recreational areas. Flooding Direct potential negative impact upon wellbeing during construction and operation as a consequence of potential and perceived increase in flood

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risk. It is acknowledged that detailed design at the next stage will identify opportunities to mitigate flood risk. Economy 4. To maximise 6. Will it enhance Significant Positive effect (++) Traffic management on the A4 and alterations to the economic economic Direct impacts: M25 at Junction 14 and A3044 connection to benefits and to growth? The total passenger benefits are valued at Terminal 5/6 are not expected to result in change to The impacts which are support the £46.9bn and include: economic benefits to growth in addition to those in considered within this competitiveness the AC’s surface access arrangements for LHR- topic are considered at a of the UK  Lower fares: £54.5bn; ENR. national scale, rather economy.  Frequency benefits: £2.6bn; and than a local scape. In  Reduced delays: £0.1bn. addition, the sources of No further economic benefits are Other direct benefits are as follows: assessment is The significance of business and airport proposed, because  Total producer impact: £-46.4bn; and effects is not service provision based, no change to the  Government revenue: £2.9bn. expected to change. rather than relating to overall significance is local accessibility expected. Wider economic impacts: enhancements. As a  Business output benefits: £1.1bn; and consequence, it is  Tax wedge: £0.5bn to 1.7bn assumed that there is no change to economic The trade benefits have been estimated at either £7.5bn, £14.3bn or growth as a result of £106.6bn depending on the approach taken. However, it should be noted surface access. that these are not additive to the other wider economic impacts. Total benefits (excluding trade and producer impacts): £61.7 – 62.8bn 7. Will it contribute Significant Positive effect (++) Construction of traffic management on the A4, The number and phasing to sustainable Although there will be local impacts, the extent of employment impacts at alterations to the M25 at Junction 14 and A3044 of jobs created through growth in a national level remains unclear (due to displacement). connection to Terminal 5/6 may result in a small construction of individual employment? It is also anticipated that many jobs will be created during the construction increase in employment associated with surface access schemes No further phase, although these may again be displaced from other potential construction activities to those in the AC’s surface has not been quantified. assessment is The significance of construction activities. access arrangements for LHR-ENR. It is reasonable to proposed, because effects is not assume these would be no change to the expected to change. similar to other road overall significance is schemes and are unlikely expected. to significantly affect the outcome of the assessment. 8. Will it support Significant Positive effect (++) The impacts which are the Two types of productivity-related impacts are expected to arise: Traffic management on the A4, alterations to the considered within this competitiveness M25 at Junction 14 and A3044 connection to topic are considered at a of the UK  enhanced productivity through increased trade and associated spin- Terminal 5/6 are not expected to change national scale, rather economy? off benefits; and competitiveness of the UK economy. than a local scape. In  Increased productivity through strengthening agglomerations and addition, the sources of clusters. economic benefits are No further business and airport assessment is The significance of service provision based, proposed, because effects is not rather than relating to no change to the expected to change. local accessibility overall significance is enhancements. As a expected. consequence, it is assumed that there is no change to competitiveness as a result of change to surface access. 5. To promote 9. Will it Neutral (0) Traffic management of A4, alterations to the M25 at employment incorporate Long term increases in surface passengers associated with the airport are Junction 14 and A3044 connection to Terminal 5/6 No further and economic accessibility anticipated. In addition, there are also expected to be increases in the use would improve the functioning of the surface access assessment is The significance of growth in the improvements, of surface access systems by additional users not associated with the arrangements in the short term. However, similar to proposed, because effects is not local area and particularly with airport. the AC’s surface access arrangements for LHR- no change to the expected to change. surrounding key local Under the do minimum scenario, the planned improvements to the local ENR benefits to accessibility are expected to be overall significance is region. employment transport network, particularly rail, will improve connectivity for those who negated by long term increases in demand for expected. centres and live and work near these routes. 35 However, long term increases in surface access transport systems, including the road

35 Jacobs, 2014. Local Economy Impacts: Assessment, p. 96. [online] Accessed 24/12/2015.

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areas of high airport and non-airport transport demand are expected to negate any network. Further improvements would be required to unemployment? network benefits to journey times for other users of surface access ensure accessibility benefits are sustained in the systems around the airport. Further enhancements to the surface long term. transport network may be required to ensure accessibility benefits are maintained in the long term. 10. Will it contribute Significant Positive effect (++) There is potential for traffic management on the A4 The number and phasing to growth in the The DfT developed a range of local employment estimates following from to contribute to the growth of the local economy, of jobs created through local economy? the AC’s original estimates. These indicated that between 48,000 and including potential for a small increase in overall construction of individual 97,000 additional local jobs would be generated by 2030 with between construction employment compared to the AC’s surface access schemes No further 31,000 and 63,000 generated by 2050. 36 surface access arrangements for LHR-ENR. has not been calculated assessment is The quantity and distribution of high skilled jobs has not been determined The significance of at this stage of proposed, because at this stage of the assessment. effects is not assessment. However, no change to the It is considered likely that airport expansion will serve as a catalyst to expected to change. assuming these are overall significance is business investment in the surrounding area, continuing to attract high similar to other road expected. value firms37. schemes these are Employment and business which develops, or is maintained by the unlikely to significantly expansion of the airport will benefit the local economy and enhance local affect the outcome of the economic growth. assessment. Noise 6. To minimise 11. Will it avoid or Predominant Significant Negative effects (--) Traffic management on the A4 is not expected to and where reduce the generate an increase in local traffic noise. possible reduce harmful effects Construction phase impacts are likely to be negative, with potential for The alterations to the M25 at Junction 14 and A3044 noise impacts due to exposure significance at sensitive receptors near to the runway extension or along connection to Terminal 5/6 at the roads affected on human of people and construction routes. The effects cannot yet be assessed in detail but as a remain similar in location to the AC’s surface access receptors. sensitive worst case estimate can be considered as potentially Significant Negative arrangements for LHR-ENR, so are unlikely to buildings to (--). increase noise effects. noise? The effects of changes in airspace noise exposure on the local population from the LHR-ENR scheme are considered to be predominantly The predominant Significant Negative (--). No further source of noise is The effects of changes in airspace noise exposure on local NSBs from the Aircraft and airport assessment is from aviation. LHR-ENR scheme are considered to be predominantly Significant operational noise is the proposed, because

Negative (--). predominant sources of no change to the The significance of The local effects of ground noise from the LHR-ENR scheme are noise. overall significance is effects is not considered to be Positive (+). expected. expected to change. The overall effects of the LHR-ENR scheme on the health outcomes assessed are considered to be predominantly Significant Negative (--), since it would result in increases in DALYs lost compared with the Do minimum. The local effects of airspace noise from the LHR-ENR scheme on children’s cognitive development are considered to be predominantly Significant Negative (--). The national effects of the LHR-ENR scheme are considered to be Significant Negative (--). Biodiversity 7. To protect and 12. Will it affect Significant Negative effect (--) enhance internationally, International Sites: designated nationally and SWLW SPA / Ramsar sites for nature locally Significant adverse effects have been identified with regard to; land take; conservation. designated construction disturbance; operation disturbance including flights; The assessment has biodiversity hydrological impacts; air quality changes; disturbance through increased been completed through sites? levels of bird scaring/control as part of birdstrike risk management The alterations to the M25 at Junction 14 may No further the identification of measures. increase the area of land lost from the Staines Moor assessment is The significance of designated biodiversity Windsor Forest and Great Park SAC SSSI when compared to the AC’s surface access proposed, because effects is not sites via publically Burnham Beeches SAC arrangements for LHR-ENR. no change to the expected to change. available mapping Thursley, Ash, Pirbright and Chobham SAC No effects on any other sites designated for nature overall significance is sources and a schematic Thames Basin Heaths SPA conservation. expected. layout for Iteration 4 - Richmond Park SAC Figure 3. Wimbledon Common SAC Significant adverse effects have been identified with regard to air quality impacts associated with increased traffic flow, and direct and indirect impacts upon supporting habitat as a result of the surface access strategy.

36 Department for Transport, 2017. Airport Capacity in the South East: Updated Appraisal Report 37 Jacobs, 2014. Local Economy Impacts: Assessment, p. 54. [online] Accessed 24/12/2015.

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National Sites Staines Moor SSSI Wraysbury Reservoir SSSI Wraysbury No.1 Gravel Pit SSSI Wraysbury and Hythe End Gravel Pits SSSI Kempton Park Reservoirs SSSI Potential impacts principally associated with air and water quality changes that could result in adverse effects to the habitats and species interest features of these sites. Local Sites Arthur Jacob LNR, East Poyle Meadows SNCI, Greenham's Fishing Pond SINC, Lower Colne Sites of Metropolitan Importance for Nature Conservation (SMINC), River Colne. Potential impacts from direct land take due to surface access requirements. 8. To conserve 13. Will it conserve Significant Negative effect (--) The alterations to the M25 at Junction 14 would and enhance and enhance Habitats cross the Colne River, Wraysbury River and undesignated undesignated deciduous woodland, numerous other watercourses. habitats, habitats, traditional orchard, It is considered feasible that the area would support species, internationally rivers and brooks, a range of species protected under UK (and EU) valuable and nationally reedbeds and wildlife legislation. ecological protected lowland meadows. networks and species and Species ecosystem valuable There are birdstrike management issues for LHR-ENR associated with functionality. ecological the nearby complex of open water bodies. The closer proximity of the networks, such runway and increased air traffic is likely to result in an increased strike The assessment has as priority risk, and a corresponding requirement for an increase in bird been completed through habitats and management and control activities is anticipated. No further the identification of priority species. Methods of deterring/scaring and controlling bird species potentially assessment is The significance of habitats via publically hazardous to aviation operations could potentially have an adverse effect proposed, because effects is not available mapping on non-target species and biodiversity including those not listed on the no change to the expected to change. sources and a schematic designation interest features. overall significance is layout for Iteration 3 - A range of protected species including, bats, otter, water vole, reptiles expected. Figure 2 (including grass snake and slow worm), and various species of birds

within 2km of the scheme boundary have been identified. It is considered feasible that the area would support a range of other species protected under UK (and EU) wildlife legislation including but not limited to dormice, and great crested newts. Potential impacts including, loss, disturbance, habitat severance/fragmentation, air and water quality changes, mortality.

14. Will it increase Assessment significance: Significant Negative effect (--) The alterations to the M25 at Junction 14 may The significance of The assessment has No further the exposure of International Sites: increase the area of land lost from the Staines Moor effects is not been completed using assessment is wildlife to SWLW SPA/Ramsar SSSI when compared to the AC’s surface access expected to change. publically available proposed, because transport noise, Windsor Forest and Great Park SAC arrangements for LHR-ENR. mapping sources and a no change to the air pollution, Burnham Beeches SAC Impacts due to exposure of wildlife include schematic layout for overall significance is and water Thursley, Ash, Pirbright and Chobham SAC disturbance, habitat severance/fragmentation, air Iteration 4 - Figure 3. expected. pollution? Thames Basin Heaths SPA and water quality changes and mortality Iteration 4 Given the scale of the Richmond Park SAC is unlikely to result in a material increase in overall impacts expected Wimbledon Common SAC exposure to these effects. this is unlikely to affect Significant adverse effects have been identified with regard to the outcome of the disturbance, air quality impacts associated with increased traffic flow, and assessment. direct and indirect impacts upon supporting habitat as a result of the surface access strategy.

National Sites Staines Moor SSSI, Wraysbury Reservoir SSSI, Wraysbury No.1 Gravel Pit SSSI, Wraysbury and Hythe End Gravel Pits SSSI,

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Kempton Park Reservoirs SSSI Potential impacts principally associated with air and water quality changes that could result in adverse effects to the habitats and species interest features of these sites.

Local Sites Arthur Jacob LNR, East Poyle Meadows SNCI, Greenham's Fishing Pond SINC, Lower Colne SMINC, River Colne. Potential impacts from direct land take due to surface access requirements

Habitats deciduous woodland, traditional orchard, rivers and brooks, reedbeds and lowland meadows.

Species A range of protected species including, bats, otter, water vole, reptiles (including grass snake and slow worm), and various species of birds within 2km of the scheme boundary have been identified. It is considered feasible that the area would support a range of other species protected under UK (and EU) wildlife legislation including but not limited to dormice, and great crested newts. Potential impacts including, disturbance, habitat severance/fragmentation, air and water quality changes, mortality. Soil 9. To protect sites 15. Will it preserve, Neutral effect No effects on sites of Geological conservation The assessment has been designated for protect and A review of sites which are designated for geodiversity reasons, including interest (SSSI or RIGS) completed through the geodiversity. improve geological SSSIs and RIGS has been undertaken. No Geological SSSIs identification via publically No further geodiversity? or RIGS were identified within this radius. No impacts on geodiversity are available mapping sources assessment is anticipated. The significance of and a schematic layout for proposed, because effects is not Iteration 4 - Figure 3. no change to the expected to change. Given the scale of the overall significance is overall impacts expected expected. this is unlikely to affect the outcome of the assessment. 10. To minimise loss 16. Will it maximise Significant Negative effect (--) The alterations to the M25 at Junction 14 and A3044 The assessment has of undeveloped construction on This scheme entails land take of 336 ha, with a further 330 ha potentially connection to Terminal 5/6 at the roads affected been completed through soils and of previously affected by surface access and 57 ha identified for flood storage. remain similar in land take area to the AC’s surface the identification via Best and Most developed land, The site area of the airport incorporates approximately 371ha of access arrangements for LHR-ENR. There would be publically available No further Versatile minimise use of agricultural land, a significant proportion of which is likely to be BMV a smaller increase in land take around Junction 14, mapping sources and a assessment is agricultural greenfield land? agricultural land. Agricultural land is a finite and irreplaceable resource, but a larger decrease in land take as the A3044 The significance of schematic layout for proposed, because land, and and although compensation will be provided to land owners, the loss of diversion to Junction 13 considered as part of the effects is not Iteration 3[SOURCE]. no change to the protect soil the land cannot be mitigated. AC's surface access arrangements for LHR-ENR expected to change. overall significance is against erosion, As a consequence of the site location, a high proportion of the land take would not be required. These are not expected to Given the scale of the expected. contamination required is from agricultural land, the quantity of PDL should be result in a change to the impacts on agricultural overall impacts expected and considered a correspondingly small proportion. land. this is unlikely to affect degradation. the outcome of the assessment. 17. Will it lead to the Negative effect (-) The alterations to the M25 at Junction 14 and A3044 The assessment has disturbing, Development may result in soil loss or burial, physical damage including connection to Terminal 5/6 at the roads affected been completed through harm, compaction, sealing, and structural damage, changes to soil water remain similar in land take area to the AC’s surface the identification of the contamination regime, effects on organic matter and soil stripping and storage. In access arrangements for LHR-ENR. There would be areas surrounding No further or loss of soil addition, development has the potential to result in contamination of soil, a smaller increase in land take around Junction 14, watercourses via assessment is The significance of resources? resulting in risks to human health or the environment. but a larger decrease in land take as the A3044 publically available proposed, because effects is not The use of large areas of previously undeveloped land will affect the diversion to Junction 13 considered as part of the mapping sources and the no change to the expected to change. quality of soil and land resources meaning these areas of land will no AC's surface access arrangements would not be route options proposed. overall significance is longer be suitable for other uses, including farming. required. These are not expected to result in a expected. change to the impacts on soil resources, including Given the scale of the due to increased potential for contamination. overall impacts expected this is unlikely to affect

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the outcome of the assessment. Water 11. To protect the 18. Will proposals Negative effect (-) No changes to the effects assessed as being quality of have adverse Physical impacts are considered in question 19 below. Water quality associated with the AC's Surface Access surface and effects on the impacts arising from polluted runoff during construction and operation. arrangements. ground waters, achievement of A further risk during construction is posed by the historic landfill within the and use water the proposed development footprint, posing a risk if contaminants are resources environmental mobilised. sustainably. objectives Two of the WFD water bodies in the study area are classified as having a established ‘Failing’ chemical status, so a potential increase in pollutants could have a under the Water more magnified impact on these water bodies. Framework A number of measures would be considered to improve water quality. The assessment has Directive? Surface water quality monitoring would be undertaken in key risk been completed through construction areas in close proximity to surface watercourses and the identification of the boreholes will be installed. areas surrounding A Sustainable Drainage Strategy will include dedicated areas for de-icing watercourses via No further aircraft and a glycol recovery procedure to reduce the concentration of publically available assessment is glycol within surface water runoff and separate storage tanks for ‘clean’ The significance of mapping sources and proposed, because and ‘first flush’ surface water. effects is not schematic layout of no change to the Possible addition of a new STW with some of the treated water to be re- expected to change. Iteration 4. overall significance is used for non-potable purposes within the airport. expected. Re-use of surface water would be maximised, including rainwater Given the scale of the harvesting, which will be installed. overall impacts expected There is potential for hydrological conditions to be altered on Staines this is unlikely to affect Moor SSSI from diversion of the River Colne and this would need to be the outcome of the addressed during detailed design. assessment. There would also be works directly adjacent to King George VI Reservoir, which forms part of Staines Moor SSSI and South West London Waterbodies Special Protection Area (SWLW SPA) and nearby Wraysbury Reservoir (also part of the SWLW SPA). This could have negative effects, depending on design (also see Appendix A.5). There are a number of reservoirs and gravel pits which make up the SWLW SPA further downstream from the Airport, (see Appendix A.5 for effects on site integrity).

19. Will it result in Significant Negative effect (--) The M25 junction 14 would require culverting of the modification Approximately 12km of existing watercourse would be replaced with watercourses including the Colne River and of diverted/realigned channels and culverts. The diversions of the Colne Wraysbury River, however this would not be a watercourses? Brook and Poyle Channel (approx. 5km) around the west end of an material increase beyond the AC's surface access extended north runway would be technically difficult and are likely to have arrangements for LHR-ENR. The assessment has effects on the hydromorphology/ geomorphology due to the changed been completed through gradients and other associated uncertainties. The alterations to the M25 at Junction 14 and A3044 the identification of An initial estimate suggests there could be in excess of 12km of additional connection to Terminal 5/6 would remove the need watercourses via culverts. The Longford River, the Duke of Northumberland’s River, River for the diversion of the A3044 to run parallel with the publically available No further Colne and Wraysbury River would be culverted underneath the proposed M25 south west of the airport in the AC's surface mapping sources and assessment is The significance of runway. access arrangements for LHR-ENR. This would schematic layout of proposed, because effects is not Water bodies are sensitive and extensive diversions/culverting would decrease the need for culverting in the area Iteration 4. no change to the expected to change. counteract improvements to waterbodies, including environmentally adjacent to the Wraysbury River. overall significance is friendly flood schemes (as part of the Lower Colne Catchment flood Given the scale of the expected. scheme) maintaining open channels for Heathrow Terminal 5. The WFD overall impacts expected strongly discourages culverting due to the detrimental impacts on the this is unlikely to affect overall environment both that of the waterbody and the surrounding area. the outcome of the There are also significant cumulative impacts from culverting on the assessment. biodiversity, soils and landscape. Changes to the sedimentation processes can lead to deterioration in water quality and could impact the waterbody status should the sediment contain contaminants. 20. Will it result in Significant Negative effect (--) The M25 junction 14 would require culverting of The assessment has the loss in Diversion of Colne Brook and Poyle Channel and culverting of the watercourses including the Colne River and been completed through productivity of Longford River, the Duke of Northumberland’s River, River Colne and Wraysbury River, however this would not be a the identification of No further fisheries? Wraysbury River may affect the hydromorphology/geomorphology which material increase beyond the AC's surface access watercourses via assessment is The significance of may cause a deterioration of the ecological status, potentially affecting arrangements for LHR-ENR. publically available proposed, because effects is not productivity of fisheries. mapping sources and no change to the expected to change. Construction of approximately 12km of culvert as part of the scheme The alterations to the M25 at Junction 14 and A3044 schematic layout of overall significance is would have negative impacts on fisheries. connection to Terminal 5/6 would remove the need Iteration 4. expected. Fisheries could also be negatively impacted by residual water quality for the diversion of the A3044 to run parallel with the impacts from polluted runoff. M25 south west of the airport in the AC's surface Given the scale of the

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access arrangements for LHR-ENR. This would overall impacts expected decrease the need for culverting in the area this is unlikely to affect adjacent to the Wraysbury River. the outcome of the assessment. The changes to culverting are not expected to result in a change to the productivity of fisheries. 21. Will it lead to an Significant Negative effect (--) The surface access modifications and traffic increase in the Total annual potable water demands for 2026 and 2050 are 2.62Mm³/year management are not anticipated to change water consumption of and 3.76 Mm³/year, respective increases of 0.32Mm³/year and 1.46 resources use during construction or operation. available water Mm³/year from 2013 demands. resources? A 77% increase in passenger numbers relative to 2013 has been forecast after the completion of the extended northern runway to 134.9 million per It is not possible to year by 2050. Rainwater harvesting is expected to account for 9% of the determine the amount of additional demand. Water efficiency measures are considered able to water resources required reduce the demand by 2 to 5%. Leakage reduction measures could also No further for construction and save up to 0.115Mm3. No figures are available for 2085 due to limitations assessment is The significance of operation at this stage of in the forecast figures and information within the WRMP. proposed, because effects is not design. Due to the scale The scheme promoter’ submission outlines that the water demands for no change to the expected to change. of the impacts associated the Shortlisted Scheme can be feasibly met by increased abstraction from overall significance is with airport expansion it surface and/or groundwater. The Affinity Water WRMP concluded that expected. is unlikely to change the there is a deficit in the Water Resource Zone that supplies Heathrow, in overall significant 2013 only 46% of the licensed volume was abstracted. presented in the AoS. Construction of the scheme will lead to short term increases in water demand.

12. To minimise 22. Will it increase Negative effect (-) The alternative M25 Junction 14 arrangements and The assessment has flood risk and flood risk Increase in impermeable areas, without suitable mitigation, could lead to traffic management on the A4 are not expected to been completed through ensure through runoff rates greater than the greenfield rate resulting in increased risks of materially increase the quantity of impermeable the identification of the resilience to increased run flooding elsewhere. There are methods of reducing flood risk. area. There is likely to be a decrease in the areas Flood Risk Zone climate change. off? Scheme promoter may need to update method for estimating the impermeable area created due to A3044 connection via publically available attenuation requirements as more appropriate methodologies are to Terminal 5/6 not being required. The Iteration 4 mapping sources and the available. Despite this the volume is similar to estimates by Jacobs. arrangements are not expected to result in a route options proposed. No further Elevated groundwater may also contribute to the surface water runoff to material increase in flood risk when compared to the assessment is the ponds during significant rainfall events or prolonged wet periods. This AC’s surface access arrangements for LHR-ENR. The significance of These could provide proposed, because may further reduce the attenuation volumes available. effects is not inaccuracies regarding no change to the expected to change. their proximity and the overall significance is extent of the Flood Risk expected. Zones in question.

Given the scale of the overall impacts expected this is unlikely to affect the outcome of the assessment. 23. Will it increase Significant Negative effect (--) The M25 junction 14 arrangement travels through area of Proposed runway will extend onto the floodplains of the River Colne, Flood Zone 2 west of the existing M25. This is not development Wraysbury River and the Colne Brook, resulting in occupying floodplain expected to result in a change to the area of within areas at areas designated as Flood Risk Zones 2 and 3. The existing fluvial flood development at risk from flooding. risk of flooding? risk to Heathrow Airport is low. There would be a decrease in the area of Development is expected to lead to a loss of up to 45 ha of undefended development within an area of flood risk due to flood plain with only a 33 ha being set aside for compensation purposes. A3044 connection to Terminal 5/6 not being No further Assessment method has potentially led to an underestimation of the loss required. assessment is The significance of of flood plain storage. Consequences of this flood storage loss would be proposed, because effects is not direct increase of flood areas downstream, with the likely impact of no change to the expected to change. increased risk to developed areas. overall significance is There are isolated areas within the extended footprint that are at medium expected. or high risk of surface water flooding. Heathrow Airport and the proposed new runway are located on River Terrace Gravels, which is classified as Primary and Secondary Aquifers. There is the potential for elevated groundwater levels and/or groundwater flooding in the area. Risk of flooding from reservoirs is considered negligible.

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Peak flow and rainfall is expected in increase from the baseline to 2086, meaning that developments on the floodplain and zones susceptible to groundwater flooding could be at risk from increases in rainfall intensity. 24. Will it be able to Negative effect (-) No information is available on design for climate adapt to climate Without appropriate mitigation the scheme could result in increased risks change. change? to itself and sites elsewhere as a result of increased peak river/overland flows, runoff rates from across the scheme and altered volumes available for abstraction for water use. No further Scheme promoter has applied a 20% increase in peak flows and rainfall, assessment is The significance of a 40% allowance will need to be assessed to be compliant with current proposed, because effects is not guidance. no change to the expected to change. No consideration appears to be given to the implications of climate overall significance is change on the River Terrace Gravels, other than the scheme will be expected. raised above existing ground levels, no consideration is given to the implications of raised ground levels across the wider area. The WRMP demonstrates that sufficient water is available to meet potable and non- potable requirements. Air Quality 13. To improve air 25. Will it support Significant Negative effect (--) Traffic management on the A4, alterations to the quality and compliance with A reassessment of compliance38 with the EU Air Quality Directive M25 at Junction 14 and A3044 connection to No further reduce local, national taking account the government’s 2017 Air Quality Plan indicates that Terminal 5/6 may reduce traffic impacts on the assessment is emissions and European existing A4, but the risk of impact on compliance is The significance of LHR-ENR impacts on compliance with EU limit values. proposed, because consistent with air quality related to airside emissions as well as traffic the effect is not NOx and PM2.5 emissions are currently projected to exceed the NECD no change to the EU, national requirements or target for 2030 – but the increase with the scheme is a very small fraction emissions and, as such, impacts are not expected to expected to change and local legislation? reduce significantly. overall significance is of the target. expected. standards and The maximum predicted annual mean NO2 concentration with the requirements. scheme in place at any receptor in Principal Study Area is 37.2µg/m3. 26. Will it reduce the Significant Negative effect (--) Traffic management on the A4, alterations to the exposure to air There are no predicted exceedances of the air quality objectives at any M25 at Junction 14 and A3044 connection to quality issues receptor location, in either the Do-Minimum or LHR-ENR scenarios. Terminal 5/6 may reduce traffic impacts on the for local existing A4, but impacts of the scheme are related to communities The scheme will increase exposure to pollution at 38,656 airside emissions as well as traffic emissions and, No further and sites 3 as such, impacts are not expected to reduce assessment is properties, of which 113 are considered ‘at risk’ (>32μg/m ). The significance of designated for significantly. proposed, because The scheme results in increased exposure to pollution over sites the effect is not nature no change to the designated for nature conservation at all 10 sites assessed, expected to change. conservation? overall significance is including sites where the critical level is currently exceeded and expected. South West London Waterbodies Ramsar/SPA. No exceedances of critical loads are modelled with the scheme. Increase in national emissions of NOx and PM2.5.

Carbon 14. To minimise 27. Will the Significant Negative effect (--) Not applicable - see Question 28 below. carbon approach to the Over the 60-year Appraisal Period (2026 to 2086), under the Carbon- emissions in development be Capped scenario, it is forecast that the development of an extended airport consistent with Northern runway at Heathrow Airport will result in the emission of a further No further construction overall carbon additional 256.1 MtCO2 over the baseline case. assessment is The significance of and operation. requirements? Over the same Appraisal Period under the Carbon-Traded scenario, it is proposed, because effects is not forecast that the development of an extended Northern runway at no change to the expected to change. Heathrow Airport will result in the emission of a further 266.7 MtCO2 over overall significance is the baseline case. expected. In both cases, construction emissions will contribute a further 10.1 MtCO2e to UK emissions, however this is a one-off impact at the beginning of the Appraisal Period. 28. Will the Significant Negative effect (--) The surface access arrangements are not expected approach Over the 60-year Appraisal Period (2026 to 2086), under the carbon- to materially alter carbon emissions from the AC’s No further minimise traded scenario, it is forecast that the development of an extended surface access arrangements for LHR-ENR. assessment is carbon Northern runway at Heathrow Airport will result in the emission of an The significance of proposed, because emissions additional 8.1 MtCO2 due to Passenger and Staff Surface Access over effects is not no change to the associated with the baseline case. expected to change. overall significance is surface In DfT’s revised carbon-capped scenario demand is unaffected by the expected. transportation? abatement measures implemented, so the surface access CO2 estimates are the same as in the carbon-traded case.

38 WSP, October 2017, 2017 Plan Update to Air Quality Re-analysis

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Emissions from staff surface access and freight transport movements are also likely to rise, but these were not quantified in the AC’s assessment. It is recommended that they be assessed by an applicant during the detailed design.

Resources 15. To minimise 29. Will it be Significant Negative effect (--) The consumption of natural, non-renewable It is not possible to and Waste consumption of possible to Consumption of large volumes of construction material. Operational resources would occur during construction and determine the amount of natural, minimise the consumption reduced by comparison with construction phase. operation. It is not anticipated that these would be waste that could be No further particularly consumption of materially different to the AC’s surface access minimised at this stage of assessment is The significance of virgin non- natural arrangements for LHR-ENR. design. Due to the scale proposed, because effects is not renewable, resources? of the impacts associated no change to the expected to change. resources. with airport expansion it overall significance is is unlikely to change the expected. overall significant presented in the AoS. 16. To minimise the 30. Will it be Significant Negative effect (--) It is not anticipated that waste generated would be It is not possible to generation of possible to Generation of large volumes of construction waste that could be sent to materially different to the AC’s surface access determine the amount of waste in minimise waste landfill. arrangements for LHR-ENR. waste that could be No further accordance generated Volumes of waste to be generated during operation are likely to be greatly minimised at this stage of assessment is The significance of with the during reduced by comparison with construction. design. Due to the scale proposed, because effects is not principals of the construction Forecasts for waste generation in operation are marginally lower than the of the impacts associated no change to the expected to change. resource and operation? highest forecasts (LHR-NWR), across all operational scenarios. with airport expansion it overall significance is efficiency is unlikely to change the expected. hierarchy. overall significant presented in the AoS. Historic 17. Conserve and 31. Will it affect the Significant Negative effect (--) Traffic management on the A4 is likely to be entirely Environment where significance of Land take study area (including surface access corridors) online, and is unlikely to increase effects on the appropriate internationally Construction activities including the demolition or partial demolition of setting of heritage assets. enhance and nationally structures will impact on 7 Grade II Listed Buildings resulting in their total heritage assets designated or partial loss. Total loss is substantial harm. Partial loss could result in There are Listed Buildings on the periphery of and the wider heritage assets assets being put at risk. Partial loss can also result in substantial harm. Stanwell Moor which may have views of the current historic and their A Conservation Area will also be affected. The significance of assets lying A3113 and M25, the proposed arrangement of the The assessment has No further environment settings? outside of the land take but associated with those within it will be at risk of M25 Junction 14 and A3044 connection to Terminal been completed through assessment is The significance of including harm. 5/6 is unlikely to generate an increase in effects information via publically proposed, because effects is not buildings, Intermediate Study Area relative to the AC’s surface access arrangements for available mapping no change to the expected to change. structures, Construction and operation will impact on the setting of 2 Scheduled LHR-ENR. sources and schematic overall significance is landscapes, Monuments, 23 listed buildings (Grades II* and II) and 5 Conservation information on Iteration 4. expected. townscapes Areas. This will result in harm to the significance of the assets. No change in the effects on designated heritage and Outer study area sites of either international or national importance archaeological Operation of the scheme will impact on the setting of a Scheduled (World Heritage Site, Scheduled Monuments and remains. Monument, 160 Listed Buildings (all Grades), a Registered Park and Registered Parks and Gardens) is anticipated. Garden and 6 Conservation Areas. This will result in harm to the significance of the assets. 32. Will it affect the Significant Negative effect (--) The A4 traffic management is likely to be entirely significance of Land take Study Area (including surface access corridors) online, and therefore is unlikely to affect non non-designated 74 assets are present. designated heritage assets. The alterations to the heritage assets Total removal of any archaeological remains during construction activities M25 J14 take place in an area which would be and their and earth-moving activities in particular. developed as part of the assessed design so no settings? The significance of non-designated remains will be subject to substantial change is predicted. harm. Intermediate Study Area The assessment has No further 79 assets are present. been completed through assessment is Any impact within the intermediate study area s will be to the significance The significance of information via publically proposed, because of the setting of the assets. This has the potential to result in harm to the effects is not available mapping no change to the significance of the assets. expected to change. sources and schematic overall significance is Outer Study Area information on Iteration 4. expected. None identified. HER search does not extend into outer Study Area. Any impact within the outer area will be to the significance of the setting of the assets. This has the potential to result in harm to the significance of the assets.

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33. Will it conserve Significant Negative effect (--) No beneficial impacts are known. or enhance No beneficial impacts are presented in the ACs report. All impacts listed heritage assets are adverse. However, it is possible that following mitigation positive and the wider outcomes could be realised through some enhancement to Conservation No further historic Areas and community engagement and by addressing Heritage at Risk assessment is environment (including those that become at risk as a result of the scheme), improving The significance of proposed, because including the setting of heritage assets, together with opportunities for community effects is not no change to the landscapes, engagement including improving access to and/or interpretation, expected to change. overall significance is townscapes, understanding and appreciation of heritage assets’ expected. buildings, structures, and archaeological remains? 34. Will it harm the Significant negative effect (--) The A4 traffic management is likely to be entirely significance of There is likely to be increased light and noise levels from construction and online, and therefore is unlikely to harm the heritage assets, operation. In addition to any lights and noise from aircraft whilst on the significance of heritage assets. for example ground and in flight. from the The setting of 30 designated heritage assets could be affected within The alterations to the M25 at Junction 14 and A3044 generation of 300m of the scheme area (1 Grade II* Listed buildings 22 Grade II, two connection to Terminal 5/6 are unlikely to materially noise, Scheduled Monuments and five Conservation Areas) and from 300m to change noise, pollution and visual intrusion on The assessment has No further pollutants and 2km the setting of a further 168 designated assets could potentially be heritage assets relative to the AC’s surface access been completed through assessment is The significance of visual intrusion? affected (four Grade I, five Grade II* and 151 Grade II Listed Buildings, arrangements for LHR-ENR. information via publically proposed, because effects is not one Scheduled Monuments and six Conservation Areas and 1 Registered available mapping no change to the expected to change. Park and Garden. sources and schematic overall significance is The setting of seventy-nine non-designated assets could be affected. information on Iteration 4. expected. Historic landscape and townscape character will be affected. Historic landscape and townscape character will be affected. There is unlikely to be an impact on below-ground archaeological remains. Data was only available for the intermediate study area i.e. 300m of the scheme area. Landscape 18. To promote the 35. Will it protect Negative effect (-) No additional effects on designated sites of either protection and and enhance National Landscape Designations: Potential indirect impacts of new international, national importance are anticipated. improvement of nationally and lighting and the direction / height / number of flights over the Chilterns landscapes locally AONB. The A4 Traffic Management would be entirely online townscapes, designated Local Landscape Designations: Long distance views from Area of to no changes to landscape character are waterscapes landscape, Landscape Importance; impacts upon the Hillingdon Lower Colne anticipated. and the visual townscape and Floodplain, Hillingdon Open Gravel Terrace, Slough Road Infrastructure The assessment has No further resource, waterscape? and Hillingdon Historic Core character areas. The alterations to the M25 at Junction 14 and A3044 been completed through assessment is The significance of including areas Local Townscape Designations: The loss of landscape features would connection to Terminal 5/6 would avoid the information via publically proposed, because effects is not of tranquillity be permanent within the Hillingdon Historic Core. requirement for a diversion of the A3044 to run available mapping no change to the expected to change. and dark skies. Other areas with landscape character value: Loss of the Colne Valley parallel with the M25. This would reduce the amount sources and schematic overall significance is Regional Park and views from the park at Colnbrook and Poyle would be of land take required within the Colne River information on Iteration 4. expected. impacted by the construction works. Floodplain landscape character area between Wraysbury and King George Reservoir. The amount of land required to accommodate a roundabout for Terminal 5/6 would also reduce landtake north west of Stanwell Moor, within the Colne River Valley Floor Landscape Character Area. 36. Will it lead to Significant negative effect (- -) The significance of effects is not expected to impact on Potential for deterioration in valued views and vistas on the Chilterns change. sensitive views AONB from the direction / height / number of flights overhead. The assessment has No further and their Views from properties in Stanwell, Stanwell Moor, Harmondsworth and been completed through assessment is The significance of settings? Sipson would be impacted during construction and operation. information via publically proposed, because effects is not Views from the Public Rights of Way south of the M4 during construction available mapping no change to the expected to change. and operation. sources and schematic overall significance is information on Iteration 4. expected.

37. Will it lead to a Negative effect (-) The assessment has No further loss of Potential for increased numbers of aircraft over-flying the Chilterns AONB, been completed through assessment is tranquillity and which may reduce tranquillity levels. Potential for increased aircraft noise The significance of effects is not expected to The significance of information via publically proposed, because increase in light and views of aircraft in flight. change. effects is not available mapping no change to the pollution? There is likely to be increased light levels from construction and expected to change. sources and schematic overall significance is operational lighting, in addition to any lights from aircraft whilst on the information on Iteration 4. expected. ground and in flight.

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Impacts would be the greatest for those receptors to the west around Colnbrook, and to the north around Harmondsworth and Sipson.

Table 8 LHR-NWR Variation Screening Assessment: M4 Widening

Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A)

Community 1. To avoid or 1. Will it lead to a loss Significant Negative effect (--) The M4 improvements would not be

minimise of housing and 39 included within the surface access negative effects community The loss of the following housing and community facilities : strategy as a necessary on community facilities?  783 residential properties likely to be required for airport expansion; improvement. The variation includes viability, improvements to the M4 as part of including  up to 289 residential properties could be required for surface access, since they fall within the the baseline of possible future housing, potential buffer zone for construction works; investment projects. The effects facilities and  potential secondary impacts of relocated households on existing communities; associated with this road are indirect effects. expected to be similar to the AC’s  loss of industrial/employment land; surface access strategy. The variation is not expected to affect a  Harmondsworth Primary School; change in the outcome of the No further  Harmondsworth Community hall (including the Wonderland day nursery); assessment. assessment is The proposed,  Sipson community centre; significance of because no effects is not  Heathrow special needs centre in Longford; change to the expected to overall change.  Nursery schools in Longford, Harmondsworth and Sipson; significance is  White Horse and Kings Arms pubs at Longford; expected.  Sipson recreation ground and facilities;  other formal and informal recreation sites;  part of the Colne Valley Regional Park; and  public rights of way;  cycle routes;  Impacts on local journey times and severance, particularly from A4/M25/Southern Rail Access works. Mitigation has been recommended.

2. Will it lead to Minor Negative effect (-) The M4 improvements would not be increasing demand included within the surface access for housing and High demand scenarios indicate up to 70,800 homes would be required. strategy as a necessary No further community improvement. The variation includes Between 300 and 500 additional homes would be required per local authority per year. assessment is facilities? improvements to the M4 as part of The proposed, Additional spaces in local schools are likely to be required and two additional GPs and two primary care the baseline of possible future significance of 40 because no centres per local authority to 2030 . investment projects. The effects effects is not change to the associated with this road are expected to There is also likely to be a need for additional parks or open spaces. overall expected to be similar to the AC’s change. significance is surface access strategy. The expected. variation is not expected to affect a change in the outcome of the assessment.

39 Airports Commission, 2014. Community: Impact Assessment, pp. 9-10. [online] Accessed 24/12/2015. 40 Airport Commission, 2014. Local Economy Impacts: Assessment, p. 109. [online] Accessed 24/12/2015.

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A)

3. Will there be indirect Significant Negative effect (--) effects on Traffic movements - may lead to more traffic and increased journey times. This may lead to issues of The M4 improvements would not be community viability? severance, loss of sense of place, breakdown in community cohesion, and a reduction in the quality of included within the surface access amenity within the community. strategy as a necessary Air Quality – 121,377 people will experience a rise in annual mean NO2 levels. No exceedances of UK improvement. The variation includes No further 41 improvements to the M4 as part of assessment is air quality objectives are anticipated. The the baseline of possible future proposed, significance of Noise – There is a predicted increase of 92,700 people exposed to airspace noise exceeding 54dB LAeq16 investment projects. The effects because no effects is not hr by 2030, reducing to 36,800 in 2050. Exposure to noise >63 dB LAeq,16hr is expected to increase by associated with this road are change to the expected to 21,700 in 2030, reducing to 2,600 by 2050. expected to be similar to the AC’s overall change. surface access strategy. The significance is Strategic Development - No allocated housing sites will be lost as a result of airport expansion, however variation is not expected to affect a expected. housing allocations to the east and west of Heathrow will be subject to noise effects, particularly around change in the outcome of the Windsor. Undeveloped land in the areas surrounding Heathrow is highly constrained by the London Green assessment. Belt and other designations. Increases in noise effects may act as an additional constraint to current housing allocations or to future housing proposals, restricting the ability of the affected local authorities to meet housing delivery targets.

2. To avoid or 4. Will it minimise Minor negative effect (-) The M4 improvements would not be minimise disproportionate included within the surface access With the loss and relocation of housing and community facilities such as the Punch Bowl Pub and primary disproportionate negative effects on strategy as a necessary No further impacts on any particular regions, school, recreational ground and transport links, disproportionate effects may be experienced by improvement. The variation includes assessment is social group. users or vulnerable vulnerable social groups within the area. Furthermore, indirect effects due to increased traffic, reduced air improvements to the M4 as part of The proposed, social groups? quality and increased noise effects may be experienced disproportionately by such groups. the baseline of possible future significance of because no investment projects. The effects effects is not There are higher than average BAME communities around the airport, with a particularly high proportion change to the associated with this road are expected to of BAME populations in the local authority areas surrounding Heathrow in Heathrow Villages, Slough and overall expected to be similar to the AC’s change. Hounslow. There is potential for BAME groups to therefore experience disproportionate effects. significance is surface access strategy. The expected. variation is not expected to affect a change in the outcome of the assessment. Traffic Volume Quality of 3. To maintain and 5. Will it help to The M4 improvements would not be Life where possible maintain and included within the surface access improve the improve quality of strategy as a necessary No further quality of life for life? improvement. The variation includes assessment is local residents improvements to the M4 as part of The proposed, and the wider the baseline of possible future significance of because no population. investment projects. The effects effects is not change to the associated with this road are expected to overall expected to be similar to the AC’s change. significance is surface access strategy. The expected. variation is not expected to affect a change in the outcome of the assessment.

41 Airports Commission, 2015. Quality of Life: Equalities Impacts Report. [online] Accessed 24/12/2015.

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) Significant disruption to road users and severance of small local communities will be experienced during the construction phase of the scheme, causing distress and anxiety to residents. During the operational period of the scheme, improved infrastructure and access to public transport may provide improvements to QoL in the short term, however these are expected to be negated by long term increasing demand for infrastructure. Housing and Communities Loss of housing/ forced moves will cause distress and have significant adverse impacts upon well-being. Social isolation likely to increase during construction from loss of community facilities, resulting in a reduction in the QoL for those directly affected by relocation or disruption during the construction period. Improvement to local infrastructure, new housing and community facilities as well as greater connectivity via improved public transport will provide greater opportunities for leisure and employment. Employment and the Economy New employment and business from an expanded airport will be of significant benefit to QoL locally and nationally from enhanced local and national economic growth. Noise Increases in significant community annoyance due to aircraft noise exposure, which can lead to stress- related changes in cardiovascular health. Loss of sleep significantly increases anxiety and hypertension.42 Noise increase in noise levels in primary schools can have a 2 month delay in reading age development. Increased road traffic growth may increase noise disturbance to nearby residents. Air Quality Effect unknown at this stage Poor air quality has a direct impact upon sensitive receptors, exacerbates symptoms surrounding cardiovascular and impaired lung functions and has strong dose-response relations with increased morbidity and mortality. Access to nature/ and cultural heritage Negative effect (-) Negative impact on the well-being of users of the recreational area and local residents who value the presence of these amenity areas. Indirect overall benefit to well-being through improving Access to Nature and the living environment, involving extensive mitigation and improvement measures. Flooding Negative effect (-) Direct potential negative impact upon well-being during construction and operation as a consequence of potential and perceived increase in flood risk. It is acknowledged that detailed design at the next stage will identify opportunities to mitigate flood risk.

Economy 4. To maximise 6. Will it enhance Significant Positive effect (++) The M4 improvements would not be economic economic growth? included within the surface access Direct impacts: No further benefits and to strategy as a necessary assessment is The support the  The total passenger benefits are valued at £67.6bn and include: improvement. The variation includes proposed, significance of competitiveness improvements to the M4 as part of because no  Lower fares: £64.3bn; effects is not of the UK the baseline of possible future change to the expected to economy. investment projects. The effects overall  Frequency benefits: £3.0bn; change. associated with this road are significance is  Reduced delays: £0.2bn; expected to be similar to the AC’s expected. surface access strategy. The Other direct benefits are as follows:; variation is not expected to affect a

42 Clark, C, 2015. Aircraft noise effects on health. [online] Accessed 30/03/2016.

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A)  Total producer impact: £-55.0bn; and change in the outcome of the assessment.  Government revenue: £3.5bn. Wider economic impacts:  Business output benefits: £1.2bn; and  Tax wedge: £0.5bn to £1.9bn. The trade benefits have been estimated at either £8.8bn, £16.7bn, or £130.9bn depending on the approach taken. However, it should be noted that these are not additive to the other wider economic impacts. Total benefits (excluding trade and producer impacts): £72.8 – 74.2bn

7. Will it contribute to Significant Positive effect (++) The M4 improvements would not be sustainable growth included within the surface access in employment? Although there will be local impacts, the extent of employment impacts at a national level remains unclear strategy as a necessary (due to displacement). improvement. The variation includes No further It is also anticipated that many jobs will be created during the construction phase. improvements to the M4 as part of assessment is The the baseline of possible future proposed, significance of investment projects. The effects because no effects is not associated with this road are change to the expected to expected to be similar to the AC’s overall change. surface access strategy. The significance is variation is not expected to affect a expected. change in the outcome of the assessment.

8. Will it support the Significant Positive effect (++) The M4 improvements would not be competitiveness of included within the surface access the UK economy? Three types of productivity-related impacts are estimated: strategy as a necessary No further improvement. The variation includes  enhanced productivity through increased trade and associated spin-off benefits; assessment is improvements to the M4 as part of The proposed,  change in tax revenue due to relocation of employment to areas with different levels of productivity; the baseline of possible future significance of because no and investment projects. The effects effects is not change to the associated with this road are expected to  increased business output. overall expected to be similar to the AC’s change. significance is surface access strategy. The expected. variation is not expected to affect a change in the outcome of the assessment.

5. To promote 9. Will it incorporate Neutral (0) The M4 improvements would not be No further employment accessibility included within the surface access assessment is Long term increases in surface passengers associated with the airport are anticipated. In addition, there The and economic improvements, strategy as a necessary proposed, are also expected to be increases in the use of surface access systems by additional users not associated significance of growth in the particularly with key improvement. The variation includes because no with the airport. effects is not local area and local employment improvements to the M4 as part of change to the surrounding centres and areas the baseline of possible future expected to Under the do minimum scenario, the planned improvements to the local transport network, particularly rail, overall region. of high investment projects. The effects change. will improve connectivity for those who live and work near these routes.43 However, long term increases in significance is unemployment? associated with this road are demand and traffic are expected to negate any benefits to journey times for other users of surface access expected. expected to be similar to the AC’s

43 Jacobs, 2014. Local Economy Impacts: Assessment, p. 96. [online] Accessed 24/12/2015.

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) systems around the airport. Further enhancements to the surface network would be required to ensure surface access strategy. The accessibility benefits are maintained in the long term variation is not expected to affect a change in the outcome of the assessment.

10. Will it contribute to Significant Positive effect (++) The M4 improvements would not be growth in the local included within the surface access economy? The DfT has developed a range of local employment estimates following from the AC’s original estimates. strategy as a necessary These indicated that between 57,000 and 114,000 additional local jobs would be generated by 2030 with improvement. The variation includes No further between 39,000 and 78,000 generated by 2050. 44 improvements to the M4 as part of assessment is The the baseline of possible future proposed, significance of The quantity and distribution of high skilled jobs has not been determined at this stage of the assessment. investment projects. The effects because no effects is not associated with this road are change to the expected to It is considered likely that airport expansion will serve as a catalyst to business investment in the expected to be similar to the AC’s overall change. surrounding area, continuing to attract high value firms45. surface access strategy. The significance is variation is not expected to affect a expected. Employment and business which develops, or is maintained by the expansion of the airport will benefit the change in the outcome of the local economy and enhance local economic growth. assessment.

Predominant Significant Negative effects (--) The M4 improvements would not be Noise 6. To minimise 11. Will it avoid or Construction phase impacts are likely to be negative, with potential for significance at sensitive receptors included within the surface access and where reduce the harmful near to the new runway or along construction routes. The effects cannot yet be assessed in detail but as a strategy as a necessary possible reduce effects due to worst case estimate can be considered as potentially Significant Negative (--). improvement. The variation includes noise impacts exposure of people improvements to the M4 as part of on human and sensitive The effects of changes in airspace noise exposure on the local population from the LHR-NWR scheme the baseline of possible future No further receptors. buildings to noise? (assessment of need carbon traded scenario) are considered to be predominantly Significant Negative (-- investment projects. The effects assessment is ). associated with this road are The proposed, expected to be similar to the AC’s significance of because no The effects of changes in airspace noise exposure on local NSBs from the LHR-NWR scheme (assessment of need carbon capped scenario) are considered to be Significant Negative (--). surface access strategy. The effects is not change to the The local effects of ground noise are considered to be Positive (+). variation is not expected to affect a expected to overall The overall effects of the LHR-NWR scheme on the health outcomes assessed are considered to be change in the outcome of the change. significance is predominantly Significant Negative (--), since it would result in increases in DALYs lost compared with the assessment. expected. Do minimum. The local effects of airspace noise from the LHR-NWR scheme on children’s cognitive development are considered to be predominantly Significant Negative (--). The national effects of the LHR-NWR scheme are considered to be mixed Positive/Significant Negative (+/--). Significant Negative effect (--) The M4 improvements would not be Biodiversity 7. To protect and 12. Will it affect included within the surface access enhance internationally, International Sites: strategy as a necessary designated nationally and SWLW SPA / Ramsar improvement. The variation includes No further sites for nature locally designated improvements to the M4 as part of assessment is Significant adverse effects have been identified with regard to; land take; construction disturbance; The conservation. biodiversity sites? the baseline of possible future proposed, operation disturbance including flights; hydrological impacts; air quality changes; disturbance through significance of investment projects. The effects because no increased levels of bird scaring/control as part of birdstrike risk management measures. effects is not associated with this road are change to the Windsor Forest and Great Park SAC expected to expected to be similar to the AC’s overall Burnham Beeches SAC change. Thursley, Ash, Pirbright and Chobham SAC surface access strategy. The significance is Thames Basin Heaths SPA variation is not expected to affect a expected. Richmond Park SAC change in the outcome of the Wimbledon Common SAC assessment.

44 Department for Transport, 2017. Airport Capacity in the South East: Updated Appraisal Report 45 Jacobs, 2014. Local Economy Impacts: Assessment, p 54. [online] Accessed 24/12/2015.

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) Significant adverse effects have been identified with regard to air quality impacts associated with increased traffic flow, and direct and indirect impacts upon supporting habitat as a result of the surface access strategy.

National Sites Staines Moor SSSI, Wraysbury Reservoir SSSI, Wraysbury No.1 Gravel Pit SSSI, Wraysbury and Hythe End Gravel Pits SSSI, Kempton Park Reservoirs SSSI Potential impacts principally associated with air and water quality changes that could result in adverse effects to the habitats and species interest features of these sites. Local Sites

Old Slade Lake Local Wildlife Sites (LWS), Lower Colne SMINC Stanwell II SNCI

Potential impacts from direct land take due to surface access requirements. Significant Negative effect (--) The M4 improvements would not be 8. To conserve 13. Will it conserve and included within the surface access and enhance enhance Habitats strategy as a necessary undesignated undesignated deciduous woodland; improvement. The variation includes habitats, habitats, traditional orchard; improvements to the M4 as part of species, internationally and rivers and brooks; the baseline of possible future valuable nationally protected reedbeds and investment projects. The effects ecological species and lowland meadows. associated with this road are networks and valuable ecological expected to be similar to the AC’s ecosystem networks, such as Species surface access strategy. The No further functionality. priority habitats and assessment is variation is not expected to affect a The priority species. There are birdstrike management issues for LHR-ENR associated with the nearby complex of open water proposed, change in the outcome of the significance of bodies. The closer proximity of the runway and increased air traffic is likely to result in an increased strike because no assessment. effects is not risk, and a corresponding requirement for an increase in bird management and control activities is change to the expected to anticipated. overall change. significance is Methods of deterring/scaring and controlling bird species potentially hazardous to aviation operations expected. could potentially have an adverse effect on non-target species and biodiversity including those not listed on the designation interest features.

A range of protected species including, bats, otter, water vole, reptiles (including grass snake and slow worm), and various species of birds within 2km of the scheme boundary have been identified. It is considered feasible that the area would support a range of other species protected under UK (and EU) wildlife legislation including but not limited to dormice, and great crested newts. Potential impacts including, loss, disturbance, habitat severance/fragmentation, air and water quality changes, mortality. Assessment significance: Significant Negative effect (--) 14. Will it increase the exposure of wildlife International Sites: to transport noise, SWLW SPA/Ramsar air pollution, and Windsor Forest and Great Park SAC No further water pollution? Burnham Beeches SAC assessment is The Thursley, Ash, Pirbright and Chobham SAC proposed, significance of Thames Basin Heaths SPA because no effects is not Richmond Park SAC change to the expected to Wimbledon Common SAC overall change. Significant adverse effects have been identified with regard to disturbance, air quality impacts associated significance is with increased traffic flow, and direct and indirect impacts upon supporting habitat as a result of the expected. surface access strategy.

National Sites Staines Moor SSSI

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) Wraysbury Reservoir SSSI Wraysbury No.1 Gravel Pit SSSI Wraysbury and Hythe End Gravel Pits SSSI Kempton Park Reservoirs SSSI Potential impacts principally associated with air and water quality changes that could result in adverse effects to the habitats and species interest features of these sites. Local Sites

Old Slade Lake LWS Lower Colne SMINC Stanwell II SNCI

Potential impacts from direct land take due to surface access requirements. Habitats deciduous woodland; traditional orchard; rivers and brooks; reedbeds and lowland meadows. Species A range of protected species including, bats, otter, water vole, reptiles (including grass snake and slow worm), and various species of birds within 2km of the scheme boundary have been identified. It is considered feasible that the area would support a range of other species protected under UK (and EU) wildlife legislation including but not limited to dormice, and great crested newts. Potential impacts including, disturbance, habitat severance/fragmentation, air and water quality changes, mortality. Neutral effect No further Soil 9. To protect sites 15. Will it preserve, A review of sites which are designated for geodiversity reasons, including geological SSSIs and RIGS has assessment is The designated for protect and improve been undertaken. No Geological SSSIs or RIGS were identified within this radius. No impacts on proposed, significance of geodiversity. geodiversity? geodiversity are anticipated. because no effects is not change to the expected to overall change. significance is expected. Significant Negative effect (--) No further 10. To minimise loss 16. Will it maximise This scheme entails land take of 569 ha, with up to further 294 ha potentially affected by surface access assessment is The of undeveloped construction on and 43 ha identified for flood storage. proposed, soils and of previously significance of The site area of the airport incorporates approximately 431ha of agricultural land, a proportion of which is because no effects is not Best and Most developed land, likely to be BMV agricultural land. Agricultural land is a finite and irreplaceable resource, and although change to the expected to Versatile minimise use of compensation will be provided to land owners, the loss of the land cannot be mitigated. overall change. agricultural greenfield land? As a consequence of the site location, a high proportion of the land take required is from agricultural land, significance is land, and the quantity of PDL should be considered a correspondingly small proportion. expected. protect soil Negative effect (-) The M4 improvements would not be against erosion, 17. Will it lead to the Development may result in soil loss or burial, physical damage including compaction, sealing, and included within the surface access contamination disturbing, harm, structural damage, changes to soil water regime, effects on organic matter and soil stripping and storage. strategy as a necessary and contamination or In addition, development has the potential to result in contamination of soil, resulting in risks to human improvement. The variation includes No further degradation. loss of soil health or the environment. improvements to the M4 as part of assessment is The resources? The use of large areas of previously undeveloped land will affect the quality of soil and land resources the baseline of possible future proposed, significance of meaning these areas of land will no longer be suitable for other uses, including farming. investment projects. The effects because no effects is not associated with this road are change to the expected to expected to be similar to the AC’s overall change. surface access strategy. The significance is variation is not expected to affect a expected. change in the outcome of the assessment.

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) Negative effect (-) Water 11. To protect the 4.1.2 18. Will proposals Physical impacts are considered in question 19 below. Water quality impacts arising from polluted runoff quality of during construction and operation. The scheme could lead to a decrease in pesticides and herbicides surface and have adverse effects on the achievement of applied to the land. ground waters, A further risk during construction is posed by the currently permitted and historic landfill within the The M4 improvements would not be and use water the environmental proposed development footprint, posing a risk if contaminants are mobilised. included within the surface access resources objectives established Long term storage would be provided to delay the additional surface water volume from being discharged strategy as a necessary sustainably. under the Water to watercourses, by infiltration, rainwater harvesting or by restricting the discharge rate to 2 litres per improvement. The variation includes No further Framework Directive? second per hectare (l/s/ha). improvements to the M4 as part of assessment is Surface runoff from paved areas (which is likely to be contaminated) would receive at least two levels of The the baseline of possible future proposed, treatment, including interception source control features. Clean water would be discharged and polluted significance of investment projects. The effects because no water treated. effects is not associated with this road are change to the The interceptor would also provide storage for any major spills. Polluted runoff would be attenuated within expected to expected to be similar to the AC’s overall a polluted water holding tank and released for treatment at a rate agreed with the treatment plant change. surface access strategy. The significance is operator; variation is not expected to affect a expected. To ensure that water resources are used efficiently rainwater harvesting will be installed along with other change in the outcome of the water saving design. assessment. There is the potential for a 10 - 15% saving on current potable water demand from the use of wastewater

recycling/reverse osmosis. There is potential for hydrological conditions to be altered on Staines Moor SSSI from diversion of the River Colne and this would need to be addressed during detailed design. There are a number of reservoirs and gravel pits which make up the SWLW SPA further downstream from the Airport, (see Appendix A.5 for effects on site integrity). Significant Negative effect (--) The M4 improvements would not be 19. Will it result in the Approximately 12km of existing watercourse would be replaced with diverted/realigned channels. included within the surface access modification of Diversion of approximately 1km of the Colne Brook around the western end of a new runway, diversions strategy as a necessary watercourses? of parts of the Duke of Northumberland’s River and River Colne to the south of the new runway and improvement. The variation includes creation of a new channel (the ‘River Colne Spur’) would be technically difficult and affect the improvements to the M4 as part of No further hydromorphology and geomorphology. the baseline of possible future assessment is Combining the River Colne and Wraysbury River into a single culvert and the Duke of Northumberland’s investment projects. The effects The proposed, and Longford Rivers into a single culvert would reduce total channel length and change the channel associated with this road are significance of because no morphology including sediment processes with concurrent ecological implications. expected to be similar to the AC’s effects is not change to the Approximately 3km of currently open channels would be culverted. The water bodies are sensitive and surface access strategy. The expected to overall extensive diversions/culverting would counteract improvements to waterbodies, including environmentally variation is not expected to affect a change. significance is friendly flood schemes (as part of the Lower Colne Catchment flood scheme) maintaining open channels change in the outcome of the expected. for Heathrow Terminal 5. The WFD strongly discourages culverting due to the detrimental impacts on the assessment. overall environment both that of the waterbody and the surrounding area. There are also significant cumulative impacts from culverting on the biodiversity, soils and landscape. Changes to the sedimentation processes can lead to deterioration in water quality and could impact the waterbody status should the sediment contain contaminants. Significant Negative effect (--) The M4 improvements would not be 20. Will it result in the Shortlisted Scheme will result in the combination of the River Colne and Wraysbury River, which would included within the surface access loss in productivity reduce total channel length significantly and could fundamentally alter the channel morphology including strategy as a necessary of fisheries? sediment processes with concurrent adverse changes to ecological status. improvement. The variation includes No further Construction of approximately 3km of culvert as part of the option Shortlisted Scheme would have improvements to the M4 as part of assessment is The adverse impacts on fisheries. the baseline of possible future proposed, significance of The fisheries could also be negatively impacted through changes in runoff rates that could mobilise investment projects. The effects because no effects is not contaminated sediments along and the residual water quality impacts from polluted runoff and impact the associated with this road are change to the expected to waterbody status. expected to be similar to the AC’s overall change. surface access strategy. The significance is variation is not expected to affect a expected. change in the outcome of the assessment.

Significant Negative effect (--) The M4 improvements would not be No further 21. Will it lead to an Total annual potable water demands for 2026 and 2050 are 2.64Mm³/year (million cubic metres per year) included within the surface access The assessment is increase in the and 3.94 Mm³/year, respective increases of 0.34Mm³/year and 1.64 Mm³/year from 2013 demands. strategy as a necessary significance of proposed, consumption of An 86% increase in passenger numbers relative to 2013 has been forecast after the completion of the improvement. The variation includes effects is not because no available water northwest runway to 150.7 million per year by 2050. Rainwater harvesting is expected to account for 2% improvements to the M4 as part of expected to change to the resources? of the additional demand. Water efficiency measures are considered able to reduce the demand by 2 to the baseline of possible future change. overall investment projects. The effects

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) 5%. Leakage reduction measures could also save up to 0.115Mm3. No figures are available for 2085 due associated with this road are significance is to limitations in the forecast figures and information within the WRMP. expected to be similar to the AC’s expected. Affinity Water has not been consulted, however the scheme promoter’s submission outlines a reduction in surface access strategy. The the reliance on potable water supply from Affinity Water both with and without the scheme. The Affinity variation is not expected to affect a Water WRMP concluded that there is a deficit in the Water Resource Zone that supplies Heathrow, in change in the outcome of the 2013 only 46% of the licensed volume was abstracted. assessment. Construction of the scheme will lead to short term increases in water demand. Negative effect (-) The M4 improvements would not be 12. To minimise 22. Will it increase flood Increase in impermeable areas, without suitable mitigation, could lead to runoff rates greater than the included within the surface access flood risk and risk through greenfield rate resulting in increased risks of flooding elsewhere. There are methods of reducing flood strategy as a necessary ensure increased run off? risk. improvement. The variation includes No further resilience to Scheme promoter appears to have underestimated the attenuation volume required based upon Jacobs improvements to the M4 as part of assessment is climate change. assessment and may need to revaluate findings as a design stage. In addition the runoff rate is greater the baseline of possible future The proposed, than the appropriate greenfield rate. As a consequence the attenuation volumes may be underestimates. investment projects. The effects significance of because no This is particularly a concern as non-paved areas draining to the ponds appears to have used a low value associated with this road are effects is not change to the for the percentage runoff from hard standing which also drains to these ponds. expected to be similar to the AC’s expected to overall Elevated groundwater may contribute to the surface water runoff to the ponds during significant rainfall surface access strategy. The change. significance is events or prolonged wet periods. This may further reduce the attenuation volumes available. variation is not expected to affect a expected. Scheme promoter has used a greenfield estimate of 4l/s/ha which is greater than that calculated for the change in the outcome of the expected rate in the AC baseline assessment of 1l/s/ha. assessment. Scheme promoter has assumed that there will be a SUDs scheme draining into attenuation tanks which will require pumping at greenfield rates. Neutral effect (0) The M4 improvements would not be 23. Will it increase area Proposed runway will extend onto the floodplains of the River Colne, Wraysbury River and the Colne included within the surface access of development Brook, resulting in development occupying floodplain areas designated as Flood Risk Zones 2 and 3. The strategy as a necessary within areas at risk existing fluvial flood risk to Heathrow Airport is low. improvement. The variation includes of flooding? Development is expected to lead to a loss of up to 40 ha of undefended flood plain with 47 ha being set improvements to the M4 as part of aside for compensation purposes. This is likely to lead to an increase in the overall flood storage for the the baseline of possible future No further catchment. The assessment of the mitigation solution does not detail how the mitigation will be achieved investment projects. The effects assessment is The or if it can be implemented without detrimental impact on the conveyance. associated with this road are proposed, significance of There are isolated areas within the extended footprint that are at medium or high risk of surface water expected to be similar to the AC’s because no effects is not flooding. surface access strategy. The change to the expected to Heathrow Airport and proposed new runway are located on River Terrace Gravels, which is classified as variation is not expected to affect a overall change. Primary and Secondary Aquifers. There is the potential for elevated groundwater levels and/or change in the outcome of the significance is groundwater flooding in the area. It is considered that groundwater flood risk is a concern across the assessment. expected. proposed site. Risk of flooding from reservoirs at the proposed site is considered negligible. Peak flow and rainfall is expected in increase from the baseline to 2086, meaning that developments on the floodplain and zones susceptible to groundwater flooding could be at risk from increases in rainfall intensity. Negative effect (-) The M4 improvements would not be 24. Will it be able to Without appropriate mitigation the scheme could result in increased risks to itself and sites elsewhere as a included within the surface access adapt to climate result of increased peak river/overland flows, runoff rates from across the scheme and altered volumes strategy as a necessary change? available for abstraction for water use. improvement. The variation includes No further Scheme promoter has applied a 20% increase in peak flows and rainfall, a 40% allowance will need to be improvements to the M4 as part of assessment is The assessed to be compliant with current guidance. The scheme promoter has also used the Environment the baseline of possible future proposed, significance of Agency’s Flood Zone 2 as a proxy for the impacts of climate change. investment projects. The effects because no effects is not No consideration appears to be given to the implications of climate change on the River Terrace Gravels. associated with this road are change to the expected to The WRMP demonstrates that sufficient water is available to meet potable and non- potable expected to be similar to the AC’s overall change. requirements. surface access strategy. The significance is variation is not expected to affect a expected. change in the outcome of the assessment.

Significant Negative effect (--) The M4 improvements would not be No further Air Quality 13. To improve air 25. Will it support included within the surface access The assessment is quality and compliance with strategy as a necessary significance of proposed, reduce local, national and improvement. The variation includes the effect will because no emissions European air quality improvements to the M4 as part of not change. change to the consistent with the baseline of possible future overall EU, national investment projects. The effects

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) and local requirements or A reassessment of compliance46 with the EU Air Quality Directive taking account the government’s 2017 associated with this road are significance is standards and legislation? Air Quality Plan indicates that LHR-NWR does not impact on compliance with EU limit values in 2030. expected to be similar to the AC’s expected. requirements. There is, however, a risk that the option will delay compliance with limit values. The risk is high until 2029. surface access strategy. The NOx and PM2.5 emissions are likely to exceed the NECD target for 2030 – but the increase with the variation is not expected to affect a scheme is a very small fraction of the target. change in the outcome of the The maximum predicted annual mean NO2 concentration with the scheme in place at any receptor in assessment. Principal Study Area is 34.7µg/m3.47 Significant Negative effect (--) The M4 improvements would not be 26. Will it reduce the included within the surface access exposure to air There are no predicted exceedances of the air quality objective at any receptor location, in either the Do strategy as a necessary quality issues for Minimum or LHR-NWR scenarios. The scheme will increase exposure to pollution at 47,063 properties, of improvement. The variation includes No further local communities which 14 are considered ‘at risk’ (>32μg/m3). There is a risk that with opening earlier than 2030 that improvements to the M4 as part of assessment is and sites exceedances of air quality objectives could occur. the baseline of possible future The proposed, designated for The scheme results in increased exposure to pollution over sites designated for nature conservation at all investment projects. The effects significance of because no

nature 7 sites assessed, including sites where the critical level is currently exceeded and South West London associated with this road are the effect will change to the conservation? Waterbodies Ramsar/SPA. No exceedances of critical loads are modelled with the scheme. expected to be similar to the AC’s not change. overall Increase in national emissions of NOx and PM2.5. surface access strategy. The significance is variation is not expected to affect a expected. change in the outcome of the assessment.

The M4 improvements would not be Carbon 14. To minimise 27. Will the approach to Significant Negative effect (--) included within the surface access carbon the development be Over the 60-year Appraisal Period (2026 to 2086), under the Carbon-Capped scenario, it is forecast that strategy as a necessary emissions in consistent with improvement. The variation includes No further the development of a third runway at Heathrow Airport will result in the emission of a further 308.5 MtCO2 airport overall carbon improvements to the M4 as part of assessment is over the baseline case48. construction requirements? the baseline of possible future proposed, Over the same Appraisal Period under the Carbon-Traded scenario, it is forecast that the development of The and operation. investment projects. The effects because no a third runway at Heathrow Airport will result in the emission of a further 327.1 MtCO2 over the baseline significance of associated with this road are change to the case49. effects is not expected to be similar to the AC’s overall In both cases, construction emissions will contribute a further 11.3 MtCO2e to UK emissions, however this expected to surface access strategy. The significance is is a one-off impact at the beginning of the Appraisal Period50. change. variation is not expected to affect a expected. change in the outcome of the assessment.

The M4 improvements would not be 28. Will the approach Significant Negative effect (--) included within the surface access minimise carbon strategy as a necessary emissions Over the 60-year Appraisal Period (2026 to 2086), under the carbon-traded scenario, it is forecast that the improvement. The variation includes No further associated with development of a third runway at Heathrow Airport will result in the emission of an additional 9.5 MtCO2 improvements to the M4 as part of assessment is The surface due to Passenger and Staff Surface Access over the baseline case51. the baseline of possible future proposed, significance of transportation? investment projects. The effects because no effects is not In the DfT’s revised carbon-capped scenario demand is unaffected by the abatement measures associated with this road are change to the expected to implemented, so the surface access CO2 estimates are the same as in the carbon-traded case expected to be similar to the AC’s overall change. surface access strategy. The significance is Emissions from freight transport movements are also likely to rise, but these were not quantified in the variation is not expected to affect a expected. DfT’s assessment. It is recommended that they be assessed by an applicant at the time of detailed change in the outcome of the design. assessment.

46 WSP, October 2017, 2017 Plan Update to Air Quality Re-analysis 47 Jacobs, 2015. Module 6: Air Quality Local Assessment - Detailed Emissions Inventory and Dispersion Modelling, p. 64. [online] Accessed 06/01/2016 48 Jacobs, 2014. Module 8. Carbon: Assessment, Table 4.18. [online] Accessed 04/01/2016. 49 Jacobs, 2015. Module 8. Carbon: Further Assessment, Table 2.12 [online] Accessed 04/01/2016. 50 Jacobs, 2014. Module 8. Carbon: Assessment, Table 4.18. [online] Accessed 04/01/2016. 51 Jacobs, 2014. Module 8. Carbon: Assessment, Table 4.18. [online] Accessed 04/01/2016.

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) Significant Negative effect (--) The M4 improvements would not be Resources 15. To minimise 29. Will it be possible to Consumption of large volumes of construction material. Operational consumption reduced by comparison included within the surface access and Waste consumption of minimise the with construction phase. strategy as a necessary No further natural, consumption of improvement. The variation includes assessment is particularly natural resources? improvements to the M4 as part of The proposed, virgin non- the baseline of possible future significance of because no renewable, investment projects. The effects effects is not change to the resources. associated with this road are expected to overall expected to be similar to the AC’s change. significance of surface access strategy. The impact is variation is not expected to affect a expected. change in the outcome of the assessment.

Significant Negative effect (--) The M4 improvements would not be 16. To minimise the 30. Will it be possible to Generation of large volumes of construction waste that could be sent to landfill. included within the surface access generation of minimise waste Volumes of waste to be generated during operation are likely to be greatly reduced by comparison with strategy as a necessary waste in generated during No further construction. improvement. The variation includes assessment is accordance construction and Forecasts for waste generation in operation are the highest of all three schemes, across all operational improvements to the M4 as part of The proposed, with the operation? scenarios the baseline of possible future significance of because no principals of the investment projects. The effects resource effects is not change to the associated with this road are expected to overall efficiency expected to be similar to the AC’s change. significance of hierarchy. surface access strategy. The impact is variation is not expected to affect a expected. change in the outcome of the assessment.

Historic 17. Conserve and 31. Will it affect the Significant Negative effect (--) Environment where significance of appropriate internationally and Land take study area (including surface access corridors) The M4 improvements would not be enhance nationally included within the surface access heritage assets designated heritage Construction activities including the demolition or partial demolition of structures will impact on 1 Grade 1 strategy as a necessary and wider assets and their listed building, 22 Grade II Listed Buildings, 2 Scheduled Monuments and 2 Conservation Areas resulting improvement. The variation includes No further historic settings? in their total or partial loss. Total loss is substantial harm. Partial loss could result in assets being put at improvements to the M4 as part of assessment is environment risk. Partial loss can also result in substantial harm. The significance of assets lying outside of the land The the baseline of possible future proposed, including take but associated with those within it will be at risk of harm. significance of investment projects. The effects because no buildings, effects is not associated with this road are change to the structures, expected to expected to be similar to the AC’s overall landscapes, change. Intermediate Study Area surface access strategy. The significance is townscapes variation is not expected to affect a expected. and Construction and operation will impact on the setting of a scheduled monument, 48 Listed Buildings (all change in the outcome of the archaeological Grades) and five Conservation Areas. This will result in harm to the significance of the assets. assessment. remains. Outer study area Operation of the scheme will impact on the setting of a Scheduled Monument, 160 Listed Buildings (all Grades) and 5 Conservation Areas. This will result in harm to the significance of the assets.

32. Will it affect the Significant Negative effect (--) The M4 improvements would not be significance of non- included within the surface access No further designated heritage Land take Study Area (including surface access corridors) strategy as a necessary assessment is The assets and their improvement. The variation includes proposed, 167 assets are present. significance of settings? improvements to the M4 as part of because no Total removal of any archaeological remains during construction activities and earth-moving activities in effects is not the baseline of possible future change to the particular. expected to investment projects. The effects overall The significance of non-designated remains will be subject to substantial harm. change. associated with this road are significance is Intermediate Study Area expected to be similar to the AC’s expected. surface access strategy. The 90 assets are present. variation is not expected to affect a

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) Any impact within the intermediate study area will be to the significance of the setting of the assets. This change in the outcome of the has the potential to result in harm to the significance of the assets. assessment.

Outer Study Area None identified. HER search does not extend into outer Study Area. Any impact within the outer area will be to the significance of the setting of the assets. This has the potential to result in harm to the significance of the assets. Significant Negative effect (--) The M4 improvements would not be 33. Will it conserve or No beneficial impacts are presented in the ACs report. All impacts listed are adverse. However, it is included within the surface access enhance heritage possible that following mitigation positive outcomes could be realised through some enhancement to strategy as a necessary assets and the Conservation Areas and community engagement and by addressing Heritage at Risk (including those improvement. The variation includes No further wider historic that become at risk as a result of the scheme), improving the setting of heritage assets, together with improvements to the M4 as part of assessment is The environment opportunities for community engagement including improving access to and/or interpretation, the baseline of possible future proposed, significance of including understanding and appreciation of heritage assets’ investment projects. The effects because no effects is not landscapes, associated with this road are change to the expected to townscapes, expected to be similar to the AC’s overall change. buildings, surface access strategy. The significance is structures, and variation is not expected to affect a expected. archaeological change in the outcome of the remains? assessment.

Significant negative effect (--) The M4 improvements would not be 34. Will it harm the There is likely to be increased light and noise levels from construction and operation in addition to any included within the surface access significance of lights and noise from aircraft whilst on the ground and in flight. strategy as a necessary heritage assets, for The setting of a further 54 designated heritage assets could be affected within 300m of the scheme area improvement. The variation includes No further example from the (1 Grade II Listed Buildings, three Grade II*, 44 Grade II, one Scheduled Monuments and five improvements to the M4 as part of assessment is generation of noise, The Conservation Areas) and from 300m to 2km the setting of a further 166 designated assets could the baseline of possible future proposed, significance of pollutants and visual potentially be affected (two Grade I, eleven Grade II* and 147 Grade II Listed Buildings, one Scheduled investment projects. The effects because no effects is not intrusion? Monuments and five Conservation Areas. associated with this road are change to the expected to The setting of ninety non-designated assets could be affected. expected to be similar to the AC’s overall change. Historic landscape and townscape character will be affected. surface access strategy. The significance is There is unlikely to be an impact on below-ground archaeological remains. variation is not expected to affect a expected. Data was only available for the intermediate study area i.e. 300m of the scheme area. change in the outcome of the assessment.

Negative effect (-) The M4 improvements would not be Landscape 18. To promote the 35. Will it protect and Nationally landscape Designation: Potential indirect impacts of new lighting and the direction / height / included within the surface access protection and enhance nationally number of flights over the Chilterns AONB. strategy as a necessary improvement of and locally Local Landscape Designations: Long distance views from Area of Landscape Importance; impacts improvement. The variation includes No further landscapes designated upon the Hillingdon Lower Colne Floodplain and the Maidenhead Settled Developed Floodplain improvements to the M4 as part of assessment is The townscapes, landscape, Local Townscape Designations: Effects on Hillingdon Historic Core character area the baseline of possible future proposed, significance of waterscapes townscape and Other areas with landscape character value: Loss of the Colne Valley Regional Park and views from investment projects. The effects because no effects is not and the visual waterscape? the park at Colnbrook and Poyle, would be impacted by the construction works. associated with this road are change to the expected to resource, expected to be similar to the AC’s overall change. including areas surface access strategy. The significance is of tranquillity variation is not expected to affect a expected. and dark skies. change in the outcome of the assessment.

Significant negative effect (- -) The M4 improvements would not be 36. Will it lead to impact Potential for deterioration through increased visual disturbance in areas of the Chilterns AONB, from included within the surface access No further on sensitive views increased number of flights overhead. strategy as a necessary assessment is and their settings? Views from properties in Stanwell, Stanwell Moor, Harmondsworth and Sipson would be impacted during improvement. The variation includes The proposed, construction and operation. improvements to the M4 as part of significance of because no Views from the Public Rights of Way south of the M4 during construction and operation. the baseline of possible future effects is not change to the investment projects. The effects expected to overall associated with this road are change. significance is expected to be similar to the AC’s expected. surface access strategy. The variation is not expected to affect a

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Topic Objective Appraisal Question Summary Of Existing Assessment (And Significance) Assumptions/ Summary Of Potential Change To Effects Likely Limitations Further (Increase Impact/ Decrease Change To Based On Assessment To Impact/ Unknown) Significance Existing Be Taken (Or Information N/A) change in the outcome of the assessment.

Negative effect (-) The M4 improvements would not be 37. Will it lead to a loss Potential for increased numbers of aircraft overflying the Chilterns AONB, which may reduce tranquillity included within the surface access of tranquillity and levels. Potential for increased aircraft noise and views of aircraft in flight. strategy as a necessary increase in light There is likely to be increased light levels from construction and operational lighting, in addition to any improvement. The variation includes No further

pollution? lights from aircraft whilst on the ground and in flight improvements to the M4 as part of assessment is

The effects would be most significant for those receptors to the west around Colnbrook and Horton and to the baseline of possible future proposed, The the north at Longford. investment projects. The effects because no significance of associated with this road are change to the effects is not expected to be similar to the AC’s overall expected to surface access strategy. The significance is change. variation is not expected to affect a expected. change in the outcome of the assessment.

Appraisal of Sustainability App D Page 79 of 79 WSP Airports Commission Project No 70030195