Heathrow Expansion PRELIMINARY ENVIRONMENTAL …...Jun 05, 2019 · Heathrow Airport, which is the Government’s preferred scheme”; “ The policies in the Airports NPS will have

Heathrow Expansion PRELIMINARY ENVIRONMENTAL INFORMATION REPORT: Chapter 3: DCO Project alternatives

© Heathrow Airport Limited 2019

Volume 1, Chapter 3

DCO Project alternatives



CONTENTS

3. DCO Project Alternatives 3.1

3.1 Introduction 3.1

3.2 Strategic alternatives 3.2

3.3 Component alternatives 3.3 Aviation 3.4 Roads 3.4 Displacements and Land Use 3.4

3.4 Aviation 3.9 Overview 3.9 Runway 3.10 Taxiways 3.12 Terminals, satellites and aprons 3.14 Aviation fuel supply, storage and distribution 3.16 Cargo 3.19 Maintenance, repair and overhaul facilities 3.21 Car parking facilities 3.22

3.5 Roads 3.26 M25 alignment 3.26 M25 junctions 3.29 A4 diversion 3.32 A3044 diversion 3.35

3.6 Displacements and land use 3.38 River diversions and flood storage 3.38 Drainage and pollution control 3.44 Utility diversions 3.48 Wastewater treatment 3.51 Home office immigration removals centre 3.53 Airport supporting development 3.55 Landscape Design and Green Infrastructure 3.58 Earthworks 3.59 Construction Support Sites 3.61

TABLE OF GRAPHICS

Graphic 3.1 Masterplan Assembly Process 3.6 Graphic 3.2: Indicative locations of runway options 3.11 Graphic 3.3: Indicative locations of taxiway options 3.13 Graphic 3.4: Indicative locations for terminal and apron growth 3.15 Graphic 3.5: Indicative locations of fuel storage facility options 3.17 Graphic 3.6: Indicative locations of truck park options 3.20 Graphic 3.7: Example of the consolidated car parking strategy 3.23 Graphic 3.8: Example of the semi-dispersed car parking strategy 3.24 Graphic 3.9: Example of the dispersed car parking strategy 3.25 Graphic 3.10: Indicative locations of M25 alignment options 3.28 Graphic 3.11: Indicative locations of M25 junction options 3.31 Graphic 3.12: Indicative locations of A4 diversion options 3.34 Graphic 3.13: Indicative locations of A3044 diversion options 3.37 Graphic 3.14: Indicative locations of flood storage site options 3.42



Graphic 3.15: Indicative locations of treatment facility options 3.46 Graphic 3.16: Indicative locations of substation relocation options 3.50 Graphic 3.17: Indicative locations of IRC replacement options 3.54 Graphic 3.18: Indicative locations of ASD opportunity sites 3.57 Graphic 3.19: Indicative locations of borrow pit site options 3.60 Graphic 3.20: Indicative locations of construction support site options 3.64


3.1 © Heathrow Airport Limited 2019

3. DCO PROJECT ALTERNATIVES

3.1 Introduction

This chapter considers the reasonable alternatives to the DCO Project. It sets out

why the preferred design has been selected over alternative options and explains

the environmental and other considerations which have been taken into account.

By way of context, it is a requirement of The Infrastructure Planning

(Environmental Impact Assessment) Regulations 2017 (the ‘EIA Regulations’) that

the Environmental Statement (ES) submitted with the application for development

consent should include:

“a description of the reasonable alternatives studied by the applicant, which are relevant to

the proposed development and its specific characteristics, and an indication of the main

reasons for the option chosen, taking into account the effects of the development on the

environment” (regulation 14(2)(d)).

This requirement is reiterated in the Airports National Policy Statement (ANPS)

(paragraph 4.28). However, with regard to the Preliminary Environmental

Information Report (PEIR), PINS Advice Note Seven explains that:

“There is no prescribed format as to what PEI[R] should comprise and it is not expected to

replicate or be a draft of the ES … the level of detail and type of PEI[R] may vary” (para.

7.4-7.5).

The information provided in this chapter will be updated for inclusion in the ES in

accordance with the EIA Regulations as the design of the DCO Project evolves

and other alternatives are considered.

Due to the scale of the DCO Project and extensive evaluation of alternatives

undertaken, this chapter focuses on the key alternatives that have been assessed

and the justification for their selection in relation to environmental effects. Context

for the components included in this chapter is set out in the Updated Scheme

Development Report (Updated SDR), which also forms part of the Airport

Expansion Consultation (June 2019). The Updated SDR explains in detail the

progress made to date in developing key components of the expanded Airport and

its supporting facilities in accordance with the scheme development process set

out in the Masterplan Scheme Development Manual (the Manual).

The level of detail provided for each alternative option in this chapter reflects the

extent of the relevant environmental consequences. It is clearly noted where all

options would have a similar environmental effect and thus the information

provided in that section is more limited. In such cases, feedback provided by other



evaluation disciplines was typically the determining factor in identifying the

preferred options.

This chapter also sign posts to where further information is available. It should be

noted that the labelling of options in this chapter does not necessarily reflect the

names used in the Updated SDR and Component Option Reports as, where

relevant, options have been grouped to explain similar environmental

consequences.

It should be noted that this chapter does not seek to repeat detail set out in the

Manual and Updated SDR but is focused on those alternative options that have

environmental consequences.

3.2 Strategic alternatives

In order to address long term airport capacity problems in London and the South-

East, the Government set up the Airports Commission in 2012, its purpose being

to determine how the UK could maintain its position as Europe’s most important

aviation hub and to examine the scale and timing of any requirement for additional

capacity.

The Airports Commission initially considered 52 proposals, with three options

developed by the Airports Commission itself.

Three schemes were shortlisted by the Airports Commission in its Interim report

(December 2013):

1. A new north-west runway at Heathrow Airport (the DCO Project)

2. A westerly extension of the northern runway at Heathrow Airport

3. A new runway at Gatwick Airport.

Studies of the proposal for a new hub airport in the inner Thames Estuary were

also continued beyond this date, but the Airports Commission concluded in

September 2014 that there were substantial disadvantages that collectively

outweighed its potential benefits and that it therefore did not represent a credible

option for shortlisting.

The Airports Commission’s Final Report was informed by a robust, integrated and

transparent process to assess the three shortlisted options, considering a range of

economic, social and environmental factors.

In light of this assessment, the Commission unanimously concluded in its final

report (July 2015) that of the three strategic alternatives, the proposal for a new

north-west runway at Heathrow Airport, in combination with a significant package



of measures to address its environmental and community impacts, presented the

strongest case.

Following a period of review and further analysis, the Government announced a

new north-west runway at Heathrow as its preferred scheme and location for

expanding airport capacity in the South-East. The ANPS was subsequently

designated in June 2018 confirming that there is a need for a third runway at

Heathrow Airport. Paragraphs 2.32-2.33 of the ANPS states that:

“Having reviewed the work of the Airports Commission and considered the evidence put

forward on the issue of airport capacity, the Government believes that there is clear and

strong evidence that there is a need to increase capacity in the South East of England by

2030 by constructing one new runway …

… the Government has identified the most effective and appropriate way to address the

overall need for increased airport capacity, and maintain the UK’s hub status, while

meeting air quality and carbon obligations and identifies that the Northwest Runway at

Heathrow is the Government’s preferred scheme”.

Paragraph 1.15 of the ANPS further confirms that:

“The Secretary of State will use the Airports NPS as the primary basis for making

decisions on any development consent application for a new Northwest Runway at

Heathrow Airport, which is the Government’s preferred scheme”;

“The policies in the Airports NPS will have effect in relation to the Government’s preferred

scheme, having a runway length of at least 3,500m and enabling at least 260,000

additional air transport movements per annum”;

“It will also have effect in relation to terminal infrastructure associated with the Heathrow

Northwest Runway scheme and the reconfiguration of terminal facilities in the area

between the two existing runways at Heathrow Airport”.

At a strategic level, the principle of the delivery of a new north-west runway at

Heathrow Airport (rather than elsewhere) is therefore firmly established within

national planning policy.

3.3 Component alternatives

Whilst the ANPS has established the need for the DCO Project, it does not fix the

design of the scheme. Rather it states that:

“While the Government has decided that a Northwest Runway at Heathrow Airport is its

preferred scheme to deliver additional airport capacity (an illustrative masterplan is at

Annex B of the Airports NPS), this does not limit variations resulting in the final scheme for

which development consent is sought” (paragraph 4.11).



In 2016, Heathrow Airport commenced a Scheme Development Process to inform

the selection of the preferred design for the DCO Project. For each component a

series of potentially feasible design alternatives were subject to a detailed

evaluation in combination with engagement with external stakeholders. Design

options were considered for the following key components of the DCO Project.

Aviation

1. Runway

2. Taxiway System

3. Terminals, satellites and aprons

4. Aviation fuel

5. Cargo

6. Maintenance

7. Car parking

Roads

1. M25 and junctions

2. Local roads.

Displacements and land use

1. River diversions and flood storage

2. Drainage and pollution control

3. Utility diversions

4. Wastewater treatment

5. Immigration Removals Centre

6. Airport supporting development

7. Landscape mitigation

8. Earthworks

9. Construction site options.

A long list of component option alternatives was considered and was reported in

the SDR which formed part of the suite of material consulted on as part of Airport

Expansion Consultation One (please refer to Chapter 1: Introduction for an

overview of Consultation One). The Consultation 1 feedback on options for each of



the components has informed further design development and the SDR has been

updated accordingly and published as part of the Airport Expansion Consultation

(June 2019).

An overview of the process and methodology that has been followed for identifying

and evaluating design options and selecting the preferred design for the DCO

Project for presentation in the Airport Expansion Consultation (June 2019), is

described below and illustrated in Graphic 3.1.



Graphic 3.1 Masterplan assembly process



The four main stages of the evaluation process undertaken further to the

requirements of the Manual are summarised as follows:

1. Stage 1 – Strategic definition: the purpose of this stage was to set the

objectives for the DCO Project and define the key inputs in the process.

Examples of these inputs include: The Strategic Brief, which sets the strategic

vision of an expanded airport and formed part of the background material for

Airport Expansion Consultation One; the Evaluation Criteria Handbook, which

outlines the criteria used for evaluating the evolving component and preferred

masterplan options; and the Requirements Register, which captures the

requirements for an expanded airport from Heathrow and stakeholders

2. Stage 2 – Component options development: The components, some of which

are key to defining the shape of the design and the associated land required for

the DCO Project, have gone through a design development process. This

involved creating a longlist of all options to be considered, reducing the number

of options under consideration through the application of discontinuation rules

where there was a high degree of confidence that a component would not meet

the requirements, and evaluating the remaining options against the evaluation

criteria which were defined in Stage 1. Full details of the evaluation criteria can

be found in the Manual. The component options that were developed in this

stage were consulted upon in Airport Expansion Consultation One. The

preferred options for each component were taken forward to Stage 3 and the

feedback from the consultation was used to improve the options

3. Stage 3 – Masterplan options development: In this stage, preferred options

from the key components were combined to create assembly options.

Feedback received during Airport Expansion Consultation One, together with

the ongoing technical engagement with stakeholders, was used to review,

improve and endorse, or change the preferred component options for inclusion

in preferred masterplan assembly. The resulting masterplan options went

through a similar process to that outlined at the Component Options

Development stage, in that the list of options was reduced by applying

discontinuation rules and the remaining options were evaluated. This stage has

recently concluded with the selection of the Preferred Masterplan which we are

now consulting on as part of the Airport Expansion Consultation (June 2019)

4. Stage 4 – Masterplan Finalisation: in this stage, the Preferred Masterplan

selected in Stage 3 will be developed further, supported by further stakeholder

engagement and the feedback from this Airport Expansion Consultation (June

2019), which consults on the Preferred Masterplan along with the alternatives

which were considered and rejected. The Preferred Masterplan will be refined

in light of on-going environmental assessment, including definition of

appropriate environmental measures to avoid or reduce the likely significant



effects of the DCO Project on communities and the environment. This stage

will conclude with the submission of the DCO application in Summer 2020.

The selected and alternative options were evaluated based upon criteria set out in

the Manual. The seven evaluation disciplines comprise:

1. Operations and Service, which includes: airfield performance, airspace

performance, passenger experience, security, hub connectivity, baggage

performance, surface access, cargo and logistics, aviation fuel infrastructure

and implications for those working at the Airport

2. Delivery, which includes: construction complexity and programme implications

3. Sustainability which includes: carbon and climate change, landscape, historic

environment, biodiversity, water, air quality, land quality, socio-economics,

noise and waste

4. Community, which includes: in-combination effects and impacts on community

facilities

5. Planning, which includes policy fit

6. Property, which includes land requirements

7. Business Case, which includes: cost, viability, commercial income, capacity

and affordability of infrastructure and viability and financeability of the case.

The evaluation process has included input provided by Delivery and Operations

disciplines, enabling each component to be assessed against criteria relevant to

the construction of the DCO Project and its future operation. As the scheme

developed, it was also necessary to evaluate aspects of construction as

components. This includes consideration of Construction Support Sites (to

facilitate delivery of the DCO Project) and potential sites at which borrow pits could

be established to source the fill material.

This preliminary DCO Project Alternatives chapter presents the reasonable

alternatives with respect to the key physical components of the Preferred

Masterplan and elements of construction which directly influence the land which

may be required to deliver the DCO Project. However, the options for how we

operate three runways in the future have also been considered and have been

subject of a process of detailed evaluation. This has included options for: runway

alternation, to manage noise and provide regular breaks from planes flying directly

over local communities (respite); directional preference, which relates to how we

choose which direction the aircraft approach and depart Heathrow; and night flight

management, the options for introducing the 6.5hr ban on scheduled night flights.

Details of the ongoing process to determine our preferred package of operational

respite measures are set out within Document 5 of the Updated SDR, as is our



initial preferred package. Furthermore, other proposed operational noise mitigation

measures are described in Chapter 18 of this PEIR and in the Future Runway

Operations document also published as part of the AEC.

While this chapter is focused on the environmental effects of each component,

other considerations are also set out where relevant to explain how the selected

component option has been selected in a balanced way considering all the criteria.

Where appropriate, the requirements that relate to an individual component are

referred to below, in particular where a requirement has negated the need to

consider alternatives that would not be acceptable. A more comprehensive

description of requirements for each component can be found in the Updated

SDR.

3.4 Aviation

Overview

The DCO Project encompasses development that will lie within the expanded

Airport’s operational boundary, as well as development beyond this boundary

which is associated with the Airport’s expansion.

The critical infrastructure necessary to operate at least an additional 260,000 Air

Transport Movements (ATMs) at Heathrow Airport will comprise:

1. North West Runway and supporting taxiway network to link with the rest of the

Airport

2. Works to the existing northern runway (the future central runway)

3. New terminal and apron capacity to enable processing of the additional

passengers and aircraft, including new passenger and baggage connectivity to

link the terminals

4. Ancillary infrastructure – for example aircraft maintenance facilities, aviation

fuel infrastructure, and cargo facilities – to enable the expanded Airport to

operate

5. Car parking facilities to enable access to Heathrow Airport, both for passengers

and colleagues.

The requirements associated with these components primarily relate to those

which are essential to operate an airport. Relative to other components, there is

limited flexibility in how these components can be arranged and consequently the

number of alternative options is less than for other components and the extent of

the difference between the environmental effects of alternative options is generally

reduced.



Runway

Introduction

The North West runway design developed by Heathrow for the Airports

Commission process sat between the communities of Colnbrook and Brands Hill

to the west, Sipson to the east and Harmondsworth to the north. Other

communities are also located nearby. It is recognised that the precise positioning

of the runway is important to Heathrow’s neighbours and the options evaluation

therefore included consideration of the potential local effects and environmental

effects associated with the runway, to understand the consequences of locational

choices.

As part of the Scheme Development Process, the length and precise location of

the runway was considered. At Stage 2, options were included for a shorter

runway than the selected option (as short as 2,295m). However, upon the

designation of the ANPS, in particular paragraph 4.3 which established a

requirement for the North West Runway to be at least 3,500m in length, it was

necessary to remove the shorter alternative options from consideration.

To permit independent parallel approaches and full runway alternation, there is a

requirement to have a minimum separation distance of 1,035m between the North

West Runway and the existing northern runway. More detail can be found in

Document 2, Chapter 1 of the Updated SDR.

Options

The following 3,500m runway options were considered (see Graphic 3.2):

1. The eastern end of the runway is fixed at a point to the west of the village of

Sipson (Family A)

2. The western end of the runway is fixed at a point to the east of the M25, with

the runway extending eastwards. This runway option does not cross the M25

(Family B)

3. The eastern end of the runway is fixed at a point to the west of the village of

Harlington, with the runway extending westwards. This option is similar to

Option 2 and explored the effects of moving the runway further eastwards

(Family C)

4. The eastern end of the runway is fixed at a point immediately to the west of the

M4 Spur motorway, with the runway extending westwards. This option explored

the effects of moving the runway approximately 300m further to the east than

Option 1, but not as far east as the Option 2 and 3, both of which extend

beyond the M4 spur (Family D).



Graphic 3.2: Indicative locations of runway options

Evaluation summary

Family A (Option 1) is the selected option. This meets the requirements of the

ANPS. It is consistent with the runway position included in the Airports

Commission scheme.

The selected option will facilitate the provision of respite from noise for local

communities, through full alternation of runway modes. It is the most preferable in

terms of the wider effects of air noise. Specifically, its location further west of the

London than other options will reduce noise effects associated with aircraft

movement across the Capital, relative to the alternatives. Unlike those alternative

options which would align the runway further to the east, the selected option would

not result in the demolition of further properties in Sipson. The selected option

does however extend to the west of the existing M25 motorway, demanding

realignment and lowering of the existing motorway. This introduces greater

complexity from a delivery perspective and is discussed further in Section 3.5:

Roads.

Option 2 and Option 3 would reduce interaction between the runway and the

existing M25 alignment and therefore have some benefits from a cost and delivery

perspective. However, these options were discontinued on environmental,

community, planning and property grounds. These options extend further east



than the selected option, would result in the additional property loss and

exacerbate noise and air quality effects at retained properties. This includes

properties in Harlington, given the proximity of these runway options to this

community.

Option 4 would cross the existing M25 alignment and introduce similar delivery

and delivery complexities as the selected option. However, as with Option 2 and

Option 3, it would also require additional demolitions of property in Sipson, whilst

not delivering any material benefits from a noise, air quality and community

perspective.

Taxiways

Introduction

Taxiways will be required to serve the new north-west runway and connect it with

the existing Airport. The system must provide efficient and safe links that deliver

predictable journey times for passengers and lower operating costs for airlines.

The taxiway system must ensure capacity and resilience can be optimised.

Some parts of the taxiway system are dependent on the terminal and apron layout.

Other sections of the taxiway network have been designed as separate

components and are therefore discussed in this section. These include:

1. The section of the taxiway system which allows aircraft to travel around the

west side of the western apron

2. The section of the taxiway system which allows aircraft entry and exit to what

will become the central runway, from north and south

3. The section of the taxiway system which allows aircraft to travel between the

new north-west runway and the existing airfield.

Based upon the need to optimise capacity, around the end taxiways (ATET) were

considered, which involve separate taxiways routed around either or both ends of

the runway, enabling aircraft to move without constraining runway operations.

Options

The following taxiway options were considered during component evaluation (see

Graphic 3.3):

1. Provision of ATETs at the eastern end of the central runway, 3 sub-options

were considered to accommodate either Code C, E or F aircraft

2. Provision of ATETs at the western end of the central runway, again 3 sub-

options were considered to accommodate either Code C, E or F aircraft



3. Provision of a Western Bypass Taxiway to the west of the Terminal 5 campus.

Following consideration of these taxiway options, an additional taxiway layout was

also identified during masterplan assembly (Stage 3):

4. Provision of a north-east taxiway to the north and east end of the central

runway.

Graphic 3.3: Indicative locations of taxiway options

Evaluation summary

As described in further detail in Document 2, Chapter 2 of the Updated SDR, a

combination of taxiway options has been selected.

Twin ‘Code F’ ATETs at the western end of the central runway have been

selected, which will enable independent operation of the central runway while

aircrafts are taxiing. This will maximise the runway throughput, avoiding taxiway

and runway congestion. Alternative Code options that are closer to the existing

runway could only accommodate smaller aircraft and would not operate as

efficiently, counter to the aim of providing an efficient airfield layout which reduces

potential fuel burn and associated emissions.

Locating the ATETs at the western end would position the taxiways nearer to the

NWR. It would also reduce the risk of associated air quality and noise effects by

virtue of locating the taxiways further away from existing communities. Specifically,

the alternative eastern ATET options would locate taxiway infrastructure

significantly closer to receptors north of the A4 Bath Road.

A Western Bypass Taxiway is also included in the preferred Masterplan. Taxiway

modelling confirmed that its removal would increase ground interactions by 25%

and average taxi delay by up to 18%, both of which are beyond an acceptable



level for operations. The inclusion of the western bypass taxiway supports efficient

operations, reducing potential fuel burn and associated emissions.

The preferred Masterplan does not include a north-east taxiway. Airfield modelling

has indicated that it is not essential and would not outweigh property and

environmental effects. As with the eastern ATETs options, a north-east taxiway

would exacerbate noise and air quality effects at receptors to the north of the A4

Bath Road.

Terminals, satellites and aprons

Introduction

Growth in passenger throughput up to and beyond 130 million passengers per

annum (mppa) will be met by a combination of physical extension and

intensification of existing terminals and satellites and development of new

terminals and satellites. More detail can be found in Document 2, Chapter 3 of the

Updated SDR.

Options

The following alternative options for the terminals (see Graphic 3.4) were

considered:

1. North: a new northern apron would be necessary to serve the expanded Airport

but there are choices for the size of that apron and location of the associated

terminal capacity, which must be on the public transport spine. A large northern

apron could result in less apron infrastructure west of Terminal 5 and retain use

of junction 14a of the M25, as well as providing an opportunity to locate airport

supporting development in this space

2. West: An enlarged western apron between Terminal 5 and the M25 motorway

could result in a smaller northern apron

3. East: Expansion of the eastern apron would require relocation of airfield

taxiway and aircraft maintenance infrastructure, which benefits from using the

existing Airport efficiently but requires significant time to build

4. Centre: The centre apron will be considered for modification to achieve higher

land use efficiency.



Graphic 3.4: Indicative locations for terminal and apron growth

Evaluation summary

Environmental considerations were not the primary determining factor in

identifying the preferred option but were considered in combination with the

performance of options against the criteria of the other evaluation disciplines,

including phasing and cost-effective delivery, airfield performance and efficiency,

passenger experience, security and baggage handling. From an environmental

perspective, the combination of expansion to the centre, north and west is

preferable over the alternative of a significantly enlarged western apron with

reduced capacity in the north, which would have more extensive effects on road



and river infrastructure to the west of Terminal 5 outside the existing Airport

boundary.

An alternative option relying on significant expansion to the east was not preferred

on the basis that it would not be on the public transport spine and would require

the relocation of the existing maintenance infrastructure, including the loss of the

Grade II Listed Technical Block A.

The combination of the three areas (north, west and centre) would also result in

less development of terminal and airfield infrastructure to the south west of Sipson,

in close proximity to existing communities.

Aviation fuel supply, storage and distribution

Introduction

An expanded Heathrow will require additional facilities for receiving, distributing

and storing fuel. The storage facilities need to hold adequate volumes of fuel to

feed the Airport in case of supply disruption. Alternative locations for fuel storage

in and around the Airport were considered.

The existing fuel railhead at Bath Road, Poyle, cannot remain in its current

location, because the proposed runway bisects the existing rail spur to the fuel

railhead. To maximise rail freight, increase fuel supply resilience and optimise the

Colnbrook branch line in the future, a fuel railhead will be required. The railhead

replacement will be provided on a like for like basis. The Colnbrook Branch Line

was considered the only suitable active railway line for the fuel railhead relocation.

More detail can be found in Document 2, Chapter 4 of the Updated SDR.

Options

The following alternative options for the fuel storage facilities (shown in Graphic

3.5) were considered:

1. Expanded Perry Oaks site: land within the existing Airport boundary which

already has connections to the existing supply pipelines and the Airport

hydrant, it is secure, and by locating the new facility immediately adjacent to

the existing site, most of the current facilities can be utilised

2. Grass Area 17a: land within the existing Airport boundary

3. Northern Apron sites: land within the expanded Airport boundary

4. Esso West London: land outside, to the south, of the Airport boundary currently

in use and adjacent to a current fuel storage facility

5. Gypsum site: land outside, to the north, of the existing Airport boundary



6. South of Esso West London: land outside, to the south, of the Airport boundary

currently in use and adjacent to a current fuel storage facility

The following alternative options for the fuel railhead replacement facility on the

Colnbrook Branch Line were considered:

1. Goodman’s Site (Colnbrook)

2. Gypsum Site at Thorney Mill Lane

Graphic 3.5: Indicative locations of fuel storage facility options



Evaluation summary

The selected option is to provide supplementary fuel storage on the northern

apron site and the expanded Perry Oaks site (Option 1 and Option 3). These sites

are within the boundary of the expanded Airport, which limits the risk of adverse

effects on landscape and townscape and views. The land would already form part

of the DCO Project and therefore the loss of agricultural land (northern apron)

would occur irrespective of this particular component. Environmental

considerations were not, however, the only determining factor in the selection of

these two sites, with other evaluation disciplines strongly supporting the case for

airside locations for reasons including, security and resilience, reduced operational

complexity, ease of delivery, and compliance with local plan designations.

Similar environmental benefits could be secured through the use of Grass Area

17a due to its location within the expanded Airport boundary. However, the use of

this site for fuel storage would displace or constrain the provision of other key

Airport infrastructure and so it was discontinued.

Outside of the Airport boundary, the alternative sites are generally more sensitive

with regards to landscape and townscape aspects due to the juxtaposition with

surrounding uses. The exception to this is the Esso West London site, where the

proposed use would be compatible with the existing site. This site has not been

progressed, however, due to the flood risk and ground instability.

At the Gypsum Site the fuel storage facilities would be surrounded by surface

water features, increasing the risk of pollution incidents and would also have the

potential for socio-economic and community effects. The site would also require

additional security features.

The selected location for the railhead replacement facility is the Goodman’s site

(Option 1). The alternative site (Option 2) was discontinued, primarily due to its

designation as a strategic freight site, however, its distance to the Airport would

also have resulted in a significant increase to local traffic on local roads and

consequently risks were identified regarding the likely air quality and noise effects

of the additional traffic.

The fuel distribution system from the storage location to the Airport hydrant system

will be developed during the next stages of the Preferred Masterplan design. Any

new distribution pipework, as with the existing pipework, will be below ground,

limiting the risk of adverse environmental effects.



Cargo

Introduction

To enable a doubling in freight handling capacity at the Airport it will be necessary

to overhaul the existing facilities and make improvements to transit facilities and

transhipment zones.

New truck park facilities have also been considered to address existing issues on

the route network and in the cargo area. The provision of a purpose-built truck

park forms part of the Heathrow cargo strategy to reduce congestion within the

cargo area, the local road system and prevent the nuisance to the local

community. More detail can be found in Document 2, Chapter 5 of the Updated

SDR.

Options

The following opportunities to enhance the cargo facilities were considered:

1. Intensification or redevelopment of existing shed facilities within the Airport

boundary

2. Provision of additional shed capacity on and adjacent to the Airport

3. Intensification or provision of dedicated transhipment facilities closer to the

aprons in order to reduce journey times and maximise utilization of cargo

facilities.

The following locations for new cargo facilities were considered:

1. Grass Area 17a, within the airport boundary

2. Gate Gourmet site, within the airport boundary

3. Terminal 4, within the airport boundary assuming demolition of Terminal 4

4. Cargo Gateway, adjacent to the airport boundary.

The following opportunities for new truck park facilities are all outside of the Airport

boundary (shown in Graphic 3.6):

1. North of new north-west runway

2. West of the M25 junction 14

3. West of the existing cargo centre

4. South of Beacon Roundabout.



Graphic 3.6: Indicative locations of truck park options

Evaluation summary

To support future cargo needs, a combination of all solutions will be required in

addition to the provision of a new truck park.

The intensification of existing cargo facilities is supported on the basis that it will

reduce the pressure on other sites within the Airport, including those in close

proximity to more sensitive receptors, and it will release land for alternative uses.

The consideration of high mechanised and low mechanised options did not raise

materially different environmental consequences.

Additional cargo provision will be located on Airport at Grass Area 17 (Option 1), in

close proximity to the existing cargo area. This site being within the Airport

boundary, reduces the potential for effects on visual receptors, as characteristics

of the view are unlikely to materially change when compared with the existing

appearance of the airfield. In comparison, an alternative site off-airport (Option 4),

would have a greater effect on visual receptors. The use of land outside of the

Airport boundary would also increase the risk of freight movements near sensitive

receptors and the loss of land used for community uses.



Although important to the selection of the preferred option, environmental reasons

were not the primary reason for choosing between cargo sites within the Airport

boundary. Other considerations included other competing uses for land and the

phasing of development while seeking to maintain existing cargo capacity.

The development of new transhipment facilities within the Airport boundary has

been selected to manage freight movements on the surrounding road network.

The alternative of intensifying existing facilities could result in a significant uplift in

the volume of vehicle movements on the road network as the quantum of cargo

passing through the control posts increases.

The selected truck park option is a variation of Option 3, located to the west of the

cargo centre on the Southern Perimeter Road close to the cargo centre, enabling

efficient access to the cargo facilities and reducing potential congestion. This

location utilises existing routes on the road network, but is in close proximity to

sensitive receptors, including the Stanwell Conservation Area and will have a

greater effect on visual receptors than other sites which are further from such

receptors.

The alternative site to the north of the runway (Option 1) is remote from the cargo

area and would be likely to introduce additional freight movements on local roads,

in turn increasing the risk of noise and air quality effects at adjacent receptors. The

distance from the cargo area would also have significant implications for efficiency.

It was not selected for this combination of reasons.

To the west of the cargo centre, Option 2 would utilise land already used as a

truck park and so freight movements may not increase significantly from today.

The site also benefits from good access to the motorway network. However, it is

also in close proximity to the Wraysbury Reservoir and vehicles movements would

not be as efficient as the selected option, given the need to traverse Junction 14

multiple times when accessing cargo facilities. Option 4, which is further from the

motorway network, would also be less efficient than the selected option requiring

vehicle movements past the cargo centre in order to access the truck park.

For the reasons set out above, the sites to the north of the runway, to the west of

the cargo centre and to the south of the Airport cargo centre, were not selected for

cargo (truck park) use.

Maintenance, repair and overhaul facilities

Introduction

Today, the Maintenance, Repair and Overhaul (MRO) facilities are located on the

eastern side of the Airport, with the sites split into an East Base and a West Base.



Discussions with airlines have highlighted the opportunity to intensify the use of

the existing facilities but also increase their flexibility by increasing hangar size

rather than the number of hangar bays. More detail can be found in Document 2,

Chapter 6 of the Updated SDR.

Options

The following alternative approaches to MRO have been considered, all of which

are located within the Airport boundary:

1. Family A: all MRO at Heathrow is consolidated in a single zone at the eastern

end of the airfield

2. Family B: MRO is dispersed across the aprons to be closer to terminal

operations

3. Family C: MRO is centralised in one location, but with a degree of

decentralisation, such as a Forward Maintenance Unit (FMU) near the apron of

a home-based operator. This option family safeguards facilities for a new

home-based entrant.

Evaluation summary

Due to the nature of the works undertaken in an MRO facility, which can potentially

be very disruptive, a requirement to ensure that options do not create

unacceptable environmental effects, such as ground noise due to the location of

ground run pens, traffic generation and air quality was agreed prior to evaluating

the component options. As a consequence, the alternative options do not result in

materially different environmental effects.

The selected option (Family C) would make provision for the growth and

redevelopment of existing MRO facilities in the existing location on the eastern

side of the Airport. Some hangars will be retained, with new facilities delivered

alongside. A site on the northern apron would provide a new FMU nearer to the

aprons. The primary determining factors in selecting this option related to

efficiency of operations and delivery.

Car parking facilities

Introduction

There are several key requirements that have been identified that will influence the

provision of car parking at Heathrow in association with the DCO Project.

The precise parking numbers in the expanded Airport are still subject to change as

they are directly related to the development of the Surface Access Strategy (SAS),



modelling and forecast parameters which are still subject to refinement and

development. More detail can be found in Document 2, Chapter 7 of the Updated

SDR.

Options

Three strategies for car parking have been considered (examples shown in

Graphic 3.7, Graphic 3.8, and Graphic 3.9):

1. Consolidated – existing car parking is consolidated into a single parking site to

serve each of the terminal complexes.

2. Semi-dispersed – The merging of Heathrow’s existing dispersed parking into a

maximum of two parking sites to serve each of the terminal complexes

3. Dispersed – The scattered distribution of parking across the Airport.

The option to utilise underground levels to reduce massing has been considered

with all options.

Graphic 3.7: Example of the consolidated car parking strategy



Graphic 3.8: Example of the semi-dispersed car parking strategy



Graphic 3.9: Example of the dispersed car parking strategy

Evaluation summary

The selected option comprises two consolidated car parks referred to as the

Northern and Southern Parkways, as well as additional car parking spaces at

Terminal 4 and within the Central Terminal Area and the retention of car parking in

the western campus. There will also be additional coach and lorry parking areas.

The proposed parkway concept enables consolidation of parking spaces in a small

number of highly accessible locations. The efficiencies in the scale of development

reduces land take in sensitive locations – this includes reducing the loss of Green

Belt. It is also considered to reduce the potential for circulating vehicle movements

on the road network around the airport perimeter. However, the Parkways require

massing of such a scale that there is a significant risk of adverse effects on the

surrounding landscape and neighbouring visual receptors. Environmental effects,

outweighed by the opportunity to provide convenient and cost-effective access to

the terminals, were not the primary reason for selecting the consolidated

Parkways.

The alternative approaches (dispersed and semi-dispersed) assume reduced

density in the Parkways. However, this would increase the requirement for



additional land, including within the Green Belt. Alternatively, land within the

expanded Airport boundary could be used, but it would subsequently displace

other uses to land outside of the Airport boundary (likely to be within the Green

Belt and other sensitive landscapes).

The opportunity to reduce the massing of multi-storey car parks by providing levels

below ground was considered. This option was preferred, on balance, by the

environmental discipline for the reduced visual effects, notwithstanding the

requirement for major earthworks. It was not progressed due to the high cost of

construction and maintenance and potential delays to the delivery programme.

The selected Parkway locations – close to major transport routes – will reduce the

potential for congestion on local roads and associated air quality effects. In

contrast, the alternative locations for dispersed car parking further away from the

Airport would need to be accessed using local roads, which would risk additional

congestion and the associated air quality effects.

Two options for the Northern Parkway were considered, one either side of the M4

Spur. The selected site, to the east of the M4 spur and west of Harlington, was

considered, on balance, to be a more appropriate location within the Green Belt

(both sites were in the Green Belt but this site was considered less damaging to it)

for a Parkway. The selected site will result in the partial loss of community

facilities, which will need to be replaced. The alternative, to the west of the M4

Spur, would have resulted in the Parkway being in closer proximity to designated

heritage assets in Harmondsworth and compromise habitat connectivity between

the Colne and Crane valleys.

Two options for the Southern Parkway were also considered, one with the diverted

rivers to the north of the Parkway and one with the rivers to the south. The rivers

passing to the south was selected on the basis that it would create a wider buffer

between the local community and the Parkway, reducing the effect on sensitive

receptors and providing greater opportunities for appropriate landscaping

measures.

3.5 Roads

M25 alignment

Introduction

As set out in Section 3.4, the selected runway is 3500m in length and is positioned

immediately to the west of the village of Sipson, extending beyond the existing

alignment of the M25. The runway would therefore necessitate either a crossing of

the motorway infrastructure, or diversion of the motorway alignment to avoid this



interface. More detail can be found in Document 3, Chapter 1 of the Updated

SDR.

Options

The following options (shown in Graphic 3.10) were considered:

1. Retention of the existing horizontal alignment. Two sub-options were

considered: either retaining both the current horizontal and vertical alignment

(minimising works to the carriageway); or retaining the current horizontal

alignment but lowering the carriageway to reduce the height of the runway.

2. Localised realignment of the horizontal alignment approximately 150m to the

west of the existing route and lowering of the carriageway, retaining Junction

15 in its current configuration. Two sub-options were considered: either with or

without the provision for dedicated collector-distributor roads.

3. A more extensive realignment of the M25 to the west, such that the

carriageway would be moved far enough to avoid conflicts with a 3,500m

runway, tying into the existing alignment north of Junction 15.



Graphic 3.10: Indicative locations of M25 alignment options



Evaluation summary

Option 2 is the selected option. The Preferred Masterplan also includes collector-

distributor roads to run alongside the main through carriageways of the M25 to

serve turning traffic (such as that using the M25 to travel to / from the Airport,

communities to the west or the M4), with through traffic travelling on the central

carriageways. This is considered to support improvements in overall journey times,

increased resilience of the motorway and optimise safety and wayfinding for road

users.

Option 2 would allow the new section of carriageway and tunnel under the

proposed runway to be constructed largely offline from the existing alignment. This

significantly reduces the risk of traffic disruption and associated environmental

effects during the construction phase, such as those on local air quality. It also

provides greater opportunity to lower the vertical alignment of the carriageway

than Option 1. This facilitates the optimal balance between highway geometry and

runway height, the latter of which influences both the amount of earthworks fill

required and the potential landscape and visual impacts of the runway.

Option 1 would require temporary diversion of the motorway to undertake the

works necessary to bridge over the existing carriageway. Online construction

would therefore increase complexity, due to the need to maintain traffic flows on

this section of the motorway. This is likely to result in greater disruption than the

selected option. Retaining the vertical alignment of the carriageway would result in

the elevation of the runway being approximately 4-5m greater than the selected

option, increasing the volume of earthworks and risk of adverse effects on the

surrounding landscape and neighbouring visual receptors. The gradient is also

unlikely to be achievable for operational reasons.

Option 3 would require the motorway alignment to be diverted sufficiently far to the

west to avoid interaction with the runway. To facilitate such an alignment,

additional properties demolitions within the Poyle, Colnbrook and Richings Park

would be required. Retained properties would be subject to adverse traffic noise,

air quality and visual effects. Other likely effects include loss of additional habitat,

greater interaction with landfill sites and additional water course crossings. Due to

the likely environmental effects, associated costs, construction complexity and

planning risks, this Option 3 was discontinued.

M25 junctions

Introduction

The western expansion of the airfield interacts directly with the existing layout of

Junction 14A (J14A) of the M25, and, to a lesser extent, Junction 14 (J14). There

is also a relationship with the M25 alignment options discussed in the previous



section and these junctions. Specifically, in the absence of collector-distributor

roads (which segregate turning traffic), to reduce risks associated with weaving

traffic, the removal of J14A was considered. This would in effect move the merge

point on the northbound carriageway south to J14. As such, it would provide a

greater distance for turning traffic utilising J14 or J15, and through traffic

continuing north/south, to orientate themselves in the correct carriageways.

The other key factor influencing the M25 junction arrangements is the projected

distribution of additional passengers across the expanded Airport. This is likely to

result in re-distribution of Airport-related traffic, which could result in changes in

traffic flow through both J14 and J14A. More detail can be found in Document 3,

Chapter 1 of the Updated SDR.

Options

The following key options (shown in Graphic 3.11) were considered:

1. Removal of J14A and substantial upgrade to J14 in its existing location. Were

J14A removed, upgrading of J14 would be required to improve junction

performance and enhance capacity, necessitating construction of additional

grade separated flyover structures. These flyover carriageways would provide

access to the western campus and proposed southern parkway, extending east

of J14, running parallel to the existing alignment of the A3113

2. Removal of J14A and re-configuration of J14 to the south of the existing

junction location. A number of sub-options were considered, all of which

involved shifting J14 approximately 500m further south and utilising land to the

east and west of the existing M25 alignment. Reconfiguration of the junction to

the south would require multiple grade separated carriageways. The A3113

would also require realignment to the south of the existing route to tie into the

relocated junction.

3. Retention of the two existing M25 junctions with minimal alteration and without

lane segregation (collector-distributor roads). This option would involve minimal

alteration to the existing motorway junction layout.

4. Retention of the two M25 junctions, supplemented by a collector-distributor

system between J14 and J15. The existing J14 layout is largely retained, with

extension of the existing roundabout to the west to accommodate a junction

with the realigned A3044. Given the interface with the expanded Airport

boundary, western terminal area and re-aligned Twin Rivers, amendments

would be required to J14A.



Graphic 3.11: Indicative locations of M25 junction options

Evaluation summary

Option 4 is the selected option. As discussed in relation to the M25 alignment, the

preferred masterplan includes collector-distributor roads to segregate turning

traffic utilising the M25 junctions from through traffic, optimising capacity,

resilience, safety and wayfinding. Option 4 would retain much of the existing

Junction 14 and 14A infrastructure and therefore reduces the extent of upgrade

works to these junctions. This reduces the risk of adverse environmental effects



during both construction and operation, including those associated with additional

watercourse crossings and the introduction of elevated structures within views.

There are also programme and cost benefits of retaining a significant proportion of

the existing junction infrastructure.

Option 1 is likely to result in adverse visual effects due to the need for multiple

grade separated carriageways. A number of these additional carriageways would

be constructed to the south of the existing A3113 alignment, reducing separation

between the village of Stanwell Moor and highway infrastructure. This would

increase the risk of adverse environmental effects, including those relating to air

quality and traffic noise. The extent and complexity of the junction layout in this

option would also requires additional watercourse crossings when compared to the

selected option and demolition of further premises to the north west of J14.

Option 2 was discounted relatively early in the evaluation process. Moving the J14

to the south would significantly increase effects on the village of Stanwell Moor,

given the extent to which infrastructure encroaches towards the village. Additional

demolition of properties within the village would be required with retained

properties likely to be subject to severance and greater air quality, traffic noise and

visual effects. This option also increases interaction with the Staines Moor Site of

Special Scientific Interest (SSSI). Beyond environmental and planning issues,

construction complexity was also a key consideration when discounting this option.

Option 3 was not considered to sufficiently reduce the risk of traffic weaving.

Whilst these options were considered favourable from an environmental

perspective, due to minimal works being required, operational considerations were

the primary consideration during evaluation, including those relating to potential

congestion, delay and accident risk.

A4 diversion

Introduction

The provision of the new north-west runway and expansion of the airfield would

directly affect roads other than the M25. As a result of the DCO Project, the

existing alignment of the A4 Bath Road / Colnbrook Bypass would be severed,

between Colnbrook and the M4 Spur. This is specifically due to the location of the

new runway, provision of a northern satellite terminal and supporting apron

infrastructure and the airfield taxiway system.

The importance of re-providing the local road functions is recognised, including

public transport and walking and cycling provision. The options set out below are

there based upon providing connectivity to and from the Airport, to and from local

communities and connectivity for through traffic. The A4 may also need to



accommodate increased traffic from the closure of the Northern Perimeter Road.

More detail can be found in Document 3, Chapter 2 of the Updated SDR.

Options

The following main alternative options for the diversion of the A4 (shown in

Graphic 3.12) were considered (described west to east):

1. Diversion of a section of the A4 to the north of the expanded Airport. The

diversion would be routed immediately north of and parallel to the boundary of

the new runway and associated airfield, crossing the M25 and the diverted

Wraysbury River and River Colne, before running parallel to and north of the

diverted Duke of Northumberland’s River. At a point approximately 700m to the

east of the M25, the diversion would deviate from the northern boundary of the

expanded airfield to run immediately adjacent to the Saxon Way Industrial

Estate. It would then follow the existing alignment of Holloway Lane, crossing

the M4 spur and turning south once east of this infrastructure before merging

with the existing A4 Bath Road

2. Diversion of a section of the A4 to the north of the new third runway,

comparable to Option 1 to the west of junction between Holloway Lane and

Harmondsworth Road. However, at this point the alignment would turn south

and includes a section of tunnel under the third runway, in order to merge with

the existing A4 Bath Road alignment to the west of the Emirates Roundabout

3. Diversion of a section of the A4 to the north of the new third runway, similar to

Option 2 described above, but rather than inclusion of a short tunnel under the

runway, the diversion would be routed around the eastern end of the runway. It

would therefore run between the airfield and the western edge of Sipson and

tie into the existing A4 Bath Road west of the Emirates Roundabout. To

facilitate diversion of the A4 around the eastern end of the runway, slight

shifting of the runway to the west would be required, as would the inclusion of a

starter extension. This is an additional runway length, made available for take-

off, prior the normal runway end and commencement of the take-off run


Option 1, but connecting with the M4 Spur. This option was introduced to

explore whether existing infrastructure (i.e. the M4 spur) could be re-purposed

to reduce the works necessary to re-provide A4 connectivity

5. Diversion of a section of the A4 to the south of the new runway, which broadly

maintains the horizontal alignment of the existing A4 Bath Road/Colnbrook

Bypass. This route would again connect with the existing A4 alignment at a

point approximately 900m east of the existing A4 Colnbrook Bypass/London

Road junction. However, from this point it would be routed immediately south of



and parallel to the boundary of the new runway and associated airfield,

crossing the M25 and entering a tunnel underneath the proposed airfield

infrastructure, merging with the existing A4 alignment approximately west of

the Emirates Roundabout


Option 1, until the point at which it crosses the M4 spur. Beyond this point the

diversion extends further to the east before turning south and tying into the

existing alignment of the A4 Bath Road. A number of sub-options were

considered that would tie into the A4 Bath Road between approximately 1.9km

to 3.4km east of the Emirates Roundabout.

Graphic 3.12: Indicative locations of A4 diversion options

Evaluation summary

Option 1 is the selected route. Given this option does not require construction of a

tunnelled section, delivery complexity and associated programme risk is

significantly reduced when compared to several alternatives. Option 1 would route

the A4 within approximately 160m of properties within Harmondsworth and could

therefore exacerbate effects on views and setting, including at the listed Great

Barn and St Marys Church. However, the routing included in the Preferred

masterplan is considered to balance these considerations against the effects

associated with aligning the route further north. Specifically, increasing separation

with the village further would either result in demolition of the Saxon Way Industrial

Estate, or additional environmental effects. These would include loss and

severance of habitat within the Lower Colne SINC, which provides connectivity

between the Colne and Crane Valleys, and further displacement of flood storage.



To the east of the M4 Spur, the selected option turns south to reduce

encroachment into the greenbelt and ensure that the existing alignment of the

A408 can be utilised to tie into the A4 Bath Road.

Option 2 is comparable to the selected option west of the Holloway

Lane/Harmondsworth Road junction, however the construction of a tunnelled

section under the runway increases complexity from a delivery perspective and

has significant cost implications, whilst offering limited environmental benefits.

Option 3 was discounted, primarily based upon the likely air noise effects

associated with shifting the runway to the west, necessary to facilitate diversion of

the A4 around the eastern end of the runway.

Due to risks associated with a new junction to the M4 spur, including reduced

safety and operational efficiency, Option 4 was also discounted. This option would

also compromise resilience, in that it creates a single point of failure in the event of

disruption to the M4 spur.

The provision of a tunneled A4 route through the airfield as with Option 5 would

reduce the risk of adverse environmental effects to the north of the Airport,

including effects on setting and views in Harmondsworth and Sipson. However,

given the significant cost and delivery implications of providing a tunnel greater

than 2km in length within the airfield boundary, along with safety and security

considerations, this option was not progressed for inclusion in the preferred

masterplan.

Option 6 was discounted due to the effects diverting the A4 further to the east of

the M4 spur would have on receptors in Harlington, including potential loss of

properties and likely noise, air quality and visual effects associated with routing

traffic directly through the village.

A3044 diversion

Introduction

3.5.24 North of the Southern Perimeter Road, the existing A3044 alignment runs adjacent

to the current western boundary of the airfield and meets the A4 Colnbrook

Bypass approximately 500m to the east of the M25. The construction of the new

northern runway and extension of the western boundary of the airfield to

accommodate expansion of the Western Terminal Area, would entirely sever the

section of the A3044 between the Southern Perimeter Road and the A4 Colnbrook

Bypass.

3.5.25 As with the A4 diversion, the options for diversion of the A3044 discussed below

are based upon a number of key requirements, including the provision of

connectivity to and from the Airport, to and from local communities and



connectivity for through traffic. More detail can be found in Document 3, Chapter 2

of the Updated SDR.

Options

3.5.26 The following main options for the re-provision of the A3044 (shown in Graphic

3.13) were considered (described south to north):

1. Diversion of the A3044 approximately 200m to the west of the existing M25

alignment. This route connects with the M25 Junction 14 roundabout, running

north in parallel to the M25 and diverted Wraysbury River channel, to the point

at which it interfaces with the proposed northern runway. Here, it turns west to

follow the boundary of the expanded airfield, connecting with the existing

alignment of the A4 via a new junction approximately 900m east of the existing

A4 Colnbrook Bypass/London Road junction

2. A route comparable to Option 1 from Junction 14 of the M25 to the point at

which it interfaces with the new northern runway. However, rather than turn

west and follow the expanded Airport boundary, this alternative route continues

on a south-north bearing and includes a tunnelled section underneath the

runway, connecting with the diverted A4 to the north of the Airport and west of

the M25

3. Diversion of the A3044 east of the M25. This route connects with the A3113 at

Junction 14 and runs north in parallel to the M25 to the point at which it

interfaces with the new northern runway. At this point is routed through a

tunnelled section underneath the runway, connecting with the diverted A4 to

the north of the Airport and east of the M25

4. Diversion of the A3044 west of the M25 beyond the western edge of Poyle,

including construction of new highway infrastructure through Poyle and

Colnbrook. Several sub-options were considered, all of which would connect

with Stanwell Road immediately north of Wraysbury Reservoir and continue

north before connecting with the A4 at various points north of Colnbrook

between 0-900m east of the existing A4 Colnbrook Bypass/London Road

junction

5. An option which would utilise the existing route of Horton Road and Stanwell

Road, but upgrade the carriageway to provide sufficient capacity.



Graphic 3.13: Indicative locations of A3044 diversion options

Evaluation summary

Option 1 is the selected option. The route largely by-passes Poyle and Colnbrook

and is immediately adjacent to the M25 transport corridor. This reduces the risk of

effects on air quality and due to traffic noise, relative to the majority of the

alternatives considered. This route will necessitate demolition of a small number of

properties on the eastern edge of Poyle, though direct impacts are significantly

reduced relative to options further to the west. No designated biodiversity sites will

be crossed by the alignment, however given it is within existing flood zone and

historic landfill boundaries, appropriate environmental measures will be required.

Option 2 is comparable to Option 1 to the south of the new third runway. The

inclusion of a tunnelled section under the runway would provide localised benefits

for properties on the northern boundary of Colnbrook, given the selected option is

located in relatively close proximity to these receptors. However, due to the

significant complexity of constructing an additional tunnel under the runway,

associated costs and conflicts with the preferred M25 alignment, it was

discounted.



Option 3, as with Option 2, was discounted due to the cost and delivery

implications of providing an additional tunnel under the runway. Diversion of the

A3044 to the east of the M25 would also introduce conflicts with the river

diversions parallel to the M25, presenting a high risk for the quality of the water

environment.

Option 4 would result in the demolition of residential properties within Colnbrook

and Poyle. The evaluation concluded that adverse environmental effects at

retained properties would be likely due to the proximity of the highway, including

air quality, noise and visual effects. The Colnbrook Conservation Area and Listed

assets within would also be affected. Due to the extent of the likely environmental

effects associated with this option, in addition to planning, cost and delivery risks,

it was discounted.

The evaluation of Option 5 concluded that the associated increase in traffic flows

utilising the Horton Road and Stanwell Road corridor would result in adverse noise

and air quality impacts at receptors adjacent to the highway. Upgrading of the

existing carriageway would also be likely to affect the Horton Brook and priority

habitats. This route was also the longest diversion option considered. Due to travel

times and the more remote nature of the route, is was discounted by the

operations and service discipline.

3.6 Displacements and land use

River diversions and flood storage

Introduction

Heathrow is situated within a complex water environment, close to a number of

rivers, lakes and reservoirs. The project would extend the Airport footprint over the

Colne Valley, with the potential to affect the alignment of five rivers and

intersecting areas of floodplain storage within the valley. The ANPS sets a number

of requirements with respect to the water environment, river diversions and flood

risk management, including:

1. That the scheme follows the approach and requirements set out in the National

Planning Policy Framework in respect of flood risk

2. That the scheme takes into account the requirements of the Water Framework

Directive (WFD).

The development of options for River Diversions and Flood Storage was heavily

driven by these requirements with respect to flood risk management and the WFD.

It was important that all proposed options were able to effectively convey river

flows, both high flows and low flows, whilst ensuring that there is no increase in



flood risk to people or properties. Alongside this, a set of specific criteria were

established to consider the relevant hydro-ecological and hydro-morphological

parameters against which different potential approaches could be judged. More

detail can be found in Document 4, Chapter 1 of the Updated SDR.

Options – river diversions

An initial long list of options was developed to consider the full range of potential

approaches that could facilitate the required river diversions. This long list was

screened against a series of discontinuation rules focused on the headline

feasibility of the options. This process narrowed the options to five approaches,

grouped into two categories:

1. Rivers conveyed mainly under the new runway:

a. All rivers conveyed under the new runway, as close to their original

alignment as possible

b. All rivers conveyed under the new runway, with the exception of diverting the

Duke of Northumberland’s River to the River Crane in a new channel to the

north of the Airport

c. All rivers conveyed under the new runway, but the Colne Brook diverted

around the north-west end of the new runway

2. Rivers mainly diverted to the west of the new runway:

a. Diverting the River Colne and Wraysbury River westwards into the Colne

Brook, with flows then returned to the original Colne and Wraysbury

channels to the south of the Airport. The Duke of Northumberland’s River

and the Longford River would be conveyed under the runway

b. Diverting the River Colne and Wraysbury River westwards around the

runway but kept separate from the additional westwards diversion of the

Colne Brook. The Duke of Northumberland’s River and the Longford River

would be conveyed under the runway.

Evaluation summary

The preferred option is a composite of the two categories presented above,

comprising:

1. Diversion of the Colne Brook to the north and west of the railhead zone and

around the western end of the new runway – this option delivers a better-

functioning river environment and more valuable aquatic habitat compared to

the existing channel, whilst also enabling a larger construction logistics centre

which will aid delivery



2. Conveyance of the diverted River Colne and Wraysbury River, and the Duke of

Northumberland’s River and Longford River, under the runway in a Covered

River Corridor. The Covered River Corridor will be optimised to support

ecological connectivity as far as practicable. Further details of the Covered

River Corridor are provided in Appendix 21.3A

3. Continuation of the diverted river channels, south of the runway, around the

western perimeter of the airfield. An open river corridor between the Airport

perimeter and the M25 will provide riparian habitat and capacity for

conveyance of flood flows

4. Alignment of the Duke of Northumberland’s River and the Longford River to the

south of the A3113 and southern parkway, removing the existing inverted

siphon underneath the A3044 and replacing a section of existing trapezoidal

channel and hard bank reinforcement with a more natural watercourse and

softer banks.

All options were evaluated to determine whether the diversion of channels to the

west of the Airport would have the ability to provide ecological connectivity through

the Colne Valley for aquatic species. Evaluation of the proposed dimensions,

gradient and flow rates for the diversion channels of the River Colne, Wraysbury

River, Longford River and Duke of Northumberland’s River concluded that these

options would not provide valuable riverine habitat or ecological connectivity.

Additionally, it was determined that the diversion of flow away from the main

channel of the River Colne could have a detrimental impact on the aquatic

environment for this water body. Substantial diversion of rivers to the west of the

runway would also add significant construction logistics and sequencing

complexity, as well as conflicting with the demands from other uses for the land

parcels that would be required. As such, approaches that maintained existing

watercourses as much as possible, conveying rivers mainly under the runway,

provided the best outcome for the water environment.

Where the Colne Brook is diverted in the north west section, the diversion reduces

the number of river crossings. The alternative of bringing the channel closer to the

Airport boundary increased the number of crossings (under the A4, as well as

access bridges to the logistics area and railhead). The environmental

consequences of additional crossings, such as shadowing and biodiversity effects,

supported the selection of a route further out. Diverting the Colne Brook around

the runway was also seen as preferable from the perspective of cost.

Options – flood storage

The expansion of the Airport will encroach on the existing floodplain of the Colne

Valley, requiring additional flood storage to ensure that the scheme does not

increase flood risk to people and property. The final layout of the DCO Project will



affect the volume of compensatory flood storage required, hence the target volume

of floodplain storage to be provided would not be known until later in the Scheme

Design Process; however, this PEIR sets out the compensatory flood storage

areas required based on the work undertaken to date.

The development was therefore guided by an understanding of the scale of

compensatory flood storage required in the Preferred Masterplan, with the focus

on identifying land parcels that could appropriately be utilised to provide flood

storage. As the details of the layout are refined through the scheme development

process the arrangement of compensatory flood storage will continue to be

refined.

The following options for flood storage (as shown in Graphic 3.14) were

considered:

1. New storage within the airfield expansion area

2. New storage to the west of the airfield

3. Catchment-wide storage

4. New upstream storage

5. New storage downstream of the airfield

6. New storage on the River Crane.



Graphic 3.14: Indicative locations of flood storage site options



Evaluation summary

There are two distinct river systems which require compensatory flood storage: the

Colne Brook (to the west of the M25) and the River Colne (to the east of the M25).

There are nine locations that remain in consideration: three that provide

compensation for the western Colne Brook system; and six that provide

compensation for the eastern River Colne system. These are summarised below:

Colne Brook Flood Storage Options (West):

1. Increased conveyance through Colnbrook

2. Colne Brook at Poynings

3. Thorney Mill Road

River Colne Flood Storage Options (East):

1. Existing M25 corridor south of the Covered River Corridor

2. South of Saxon Lake

3. East of Saxon Lake

4. Long Mead

5. Thorney Park Golf Course

6. Huntsmoor Park

The flood storage options would all adopt a similar conceptual design including: a

gated river offtake structure to control the timing of the filling of the flood storage

areas; an inlet weir; an outfall structure to allow for passive draining of the flood

storage area at the end of a flood event; and an appropriate lining solution where

the flood storage area is located on landfill.

Not all sites will be required, and various site combinations continue to be tested to

match the floodplain storage lost on the Colne Brook and River Colne systems,

reflecting the wider development of the scheme.

Through option development it was recognised that parcels of land should be

multifunctional, combining flood storage, habitat creation, green infrastructure and

community or commercial uses. Flood storage options which are in close proximity

to the Airport were preferred as they are closer to proposed and existing river

alignments. These options also provide opportunities for habitat creation and

green infrastructure enhancements close to the Airport. Flood storage provides

decreasing attenuation benefits the further upstream it is. Sites upstream of the

M40 were discontinued on this basis. Further south (closer to the Airport), the

attenuation benefit of the sites improves, but also encounter potential conflicts with

construction activities and high value land.



An alternative option of flood storage located in the east involves diverting water

from the Colne Valley catchment into the Crane River catchment. This is highly

unlikely to be required or feasible to use in the context of the retained river flow

conveyance options which divert river flows further to the west, away from the

Crane Valley. As a result, the option to divert flood water to the River Crane is no

longer being considered.

The alternative of catchment wide flood management is complex to implement and

manage due to diverse and diffuse locations and the large size of the catchment.

While there are a number of environmental benefits that could be achieved, this

concept was discontinued as a primary solution for non-environmental reasons.

The provision of additional flood storage downstream, rather than upstream, of the

point at which floodplain is lost is complex as the flood water needs to be

conveyed to the storage without increasing the flood risk in other locations. This

presents a hydraulic challenge as it would be necessary to ensure that flood water

could be safely conveyed through a number of ‘pinch points’ along the river

corridors in order to access the downstream flood storage. The capital investment

required is significant. It could also affect the Staines Moor SSSI, since the

creation of additional flood storage would likely require excavation to create the

required storage volume, leading to potentially adverse habitat impacts. For these

reasons, this alternative option was discontinued.

Drainage and pollution control

Introduction

The DCO Project will result in an increase in the amount of surface water runoff to

be managed. Without the implementation of appropriate measures, this has the

potential to affect the drainage and water quality of the watercourses around the

Airport.

The existing drainage system at Heathrow comprises four catchment areas (north-

western, western, southern and eastern), which operate different treatment

methods and discharge (release) to different locations. Further detail is provided in

Document 4 Chapter 2 of the Updated SDR.

Options

The drainage and pollution control has been considered by breaking down the

options into two processes: capture and attenuate; and treat and release solutions.

The following solutions for capture and attenuate were considered:

1. Underground Airside Storage Tanks



2. Tunnel Storage, Landside Pump Station and Attenuation basin

3. Open attenuation basin to the north-west and south-west of the Airport.

The following options were considered for treatment solutions to manage glycol

contamination, based on the range of treatment technologies and approaches to

discharge available and in accordance with the requirements for drainage and

pollution control:

1. Engineered reed beds

2. Combined treatment

3. Discharge to sewer.

The development of options also needed to consider the specific location for the

provision of treatment, focusing on land around the immediate perimeter of the

airfield. Given the potential demands for land around the Airport, consideration

was also given to land parcels further afield. The sites Graphic 3.15 were

considered for treatment locations.

The following options were identified as possible systems to which water could be

released:

1. River Colne

2. Colne Brook

3. River Crane / Frog Ditch

4. Clockhouse Lane Pits

5. Stanwell Ditch

6. Duke of Northumberland River

7. Bath Road Sewer.



Graphic 3.15: Indicative locations of treatment facility options

Evaluation summary

The preferred airfield drainage and pollution control approach proposes to drain

the Expansion predominantly under gravity conditions to shallow, offsite,

co-located attenuation and treatment areas to the northwest and southwest of the

airfield (Option 3 of Capture and Attenuate).

The selected sites for open attenuation to the southwest and northwest of the

airfield (SW_NEW and NW_NEW), are close enough to the airfield that they are

able to predominantly rely on gravitational flows which is more sustainable and

more resilient. Sites further from the airfield will be more challenging to deliver due

to the length of connecting infrastructure needed. The environmental

consequences of alternative solutions that rely upon a greater use of mechanical

pumping would be only marginally worse (greater energy requirement) but would

not provide robust resilience in the event of failures or exceedance storms, and

require greater capital expenditure. It is this combination of reasons that resulted

in the selection of a predominantly gravitational solution.



The selected land parcels, although in close proximity to sensitive receptors, avoid

the loss of land for recreation that would result in socio-economic effects and land

parcels that include Sites of Importance to Nature Conservation.

The use of land containing two Scheduled Monuments at Mayfield Farm (land

parcel S-01) was considered to be possible if suitable construction methods were

employed to enable engineered reed beds to be delivered and to preserve the

archaeological remains in situ, however it is likely that this would require an

archaeological evaluation.

The alternative approach to capturing and attenuating using underground storage

tanks (Option 1) would minimise the risk of onsite flooding as it does not rely on

mechanical plant to drain the airfield and it would minimise the effects on local

habitats and communities by locating the majority of infrastructure below ground

and on airfield. However, the construction of the tanks would require significant

earthworks increasing the potential adverse noise and air quality effects on local

sensitive receptors. The approach would also necessitate the need for pumping to

the treatment location, which is less sustainable. Operational concerns, including

the complexity of maintaining the tanks, the resilience of the pumping, and the

greater capital expenditure required, were also reasons why this option was

discounted.

Option 2 for capture and attenuation, requiring the use of tunnel storage, would

also rely heavily upon the use of pumping to pump contaminated water to the

treatment area which is less sustainable. Operational concerns, including the

resilience of pumping, and the greater capital expenditure required, were also

reasons why this option was discounted.

The receiving watercourse was not deemed to be a differentiator between options,

since appropriate discharge limits will need to be agreed and met for all

watercourses. There are also requirements to ensure that all options would be

adequately sized to meet the requirements of the ANPS, including an allowance

for climate change, and that lakes or ponds would not be compromised by the

quantity and quality of discharges. Consequently, the alterative options for

watercourses to release into do not present materially different environmental

consequences.

In the assessment of treatment solutions, engineered reed beds (Option 1) were

selected as the preferred treatment approach, primarily due to non-environmental

reasons, namely that they are proven to be effective, of lower complexity and

lower cost than alternative options. The alternative treatment using a combined

foul water and surface runoff treatment plant (Option 2), would add complexity and

cost of operating a treatment works would reduce Heathrow’s operational

resilience. Option 3, a connection to the Thames Water foul sewer system, will also



be required alongside Option 1 to provide operational resilience in the event that

flows cannot be treated on site.

Utility diversions

Introduction

There is a substation and several major utility services and aviation fuel supply

pipelines that will need to be diverted, relocated or protected as a result of the

DCO Project and some services will need to be expanded to meet the increased

demands of the expanded Airport.

Heathrow has been working closely with the affected statutory undertakers and

asset owners to develop strategies for diverting or relocating assets where

required. This is being looked at in conjunction with any requirements for future

increases in capacity.

The diversion of two utilities, the National Grid Overhead Power Line and the

Scottish and Southern Electricity Network Overhead Line, are two of the most

significant diversions and have been considered in conjunction with the utility

organisations who own and operate those assets. The options for diverting these

two assets and relocating the Longford substation include options above ground

which could have environmental consequences for local receptors. Further detail

is provided in Document 4 Chapter 3 of the Updated SDR.

Options

Five options have been considered for the National Grid Overhead Line Diversion:

1. Re-route the overhead lines above ground further to the west, this would

involve installing new pylons along the M4 corridor and around the Queen

Mother Reservoir (approximately 9 km)

2. Bury the 275kV lines following a similar route to the current pylons

(approximately 2 km). Land use restrictions would be in place over the cable

route. An approximate 30mwide easement would be required along the entire

buried cable route within which no development would be permitted. Terminal

towers and sealing end compounds would be required at each end of the cable

3. Construct a deep bore tunnel between each terminal tower / sealing end

compound and head house to accommodate the relocated 275kV lines

(approximately 2km). There would be fewer land use restrictions with this

option

4. Construct a long deep bored tunnel from North of the M4 to a point near Poyle

(approximately 3.5km)



5. Construct a combined tunnel for NG and SSE from North of the M4 to a point

south of Poyle.

Five options have been considered for the Scottish and Southern Electricity

Networks Overhead Line Diversion:

1. Provide an interim diversion along the existing Network Rail railway track. A

permanent solution would be installed in the future

2. Provide an interim diversion adjacent to the M25 carriageway and a permanent

diversion along the new M25 alignment

3. Provide an interim diversion along Lakeside Road. A permanent solution would

be installed in the future

4. Provide a permanent diversion westward around the Airport commission

boundary, through agricultural land and community spaces

5. Option 5: Provide a tunnel below the proposed third runway utilising the

shortest distance possible.

Four options have been considered for the relocation of the Longford Substation

(shown in Graphic 3.16):

1. North of existing Longford substation

2. Adjacent existing Longford substation

3. West of existing Longford substation

4. South of existing Longford substation.



Graphic 3.16: Indicative locations of substation relocation options

Evaluation summary

National Grid Overhead Line Diversion

A final solution for replacement of the National Grid Overhead Power Lines has

not yet been agreed with National Grid. Options 2, 3 and 4 remain under

consideration. These options, as well as option 5, would all have similar

environmental consequences as a result of the tunnel being underground. The

sealing end compounds would need to avoid sites with sensitive environmental

receptors unless appropriate mitigation can be provided. All options would avoid

ancient woodland. Option 5 is not being pursued due to operational and phasing

reasons.



Option 1 would have more significant environmental effects, namely visual and

landscape effects. In order to move the overhead lines to a point where they no

longer clashed with the Obstacle Limitation Surfaces (OLS), it would be necessary

to have pylons in a residential area. To avoid that effect, it would be necessary to

route the overhead lines round the Queen Mother Reservoir and add

approximately 6.5km to the network length, potentially harming a greater extent of

land and affecting more receptors. National Grid has, however, confirmed that they

would not pursue this option as it would not be viable or cost effective and

therefore will pursue an underground alternative.

SSE Networks Overhead Line Diversion

For SSE, the preferred option is to temporarily divert the 132kV OHL along the

Lakeside Road in a buried trench to enable M25 works to commence (Option 3).

SSE has approved this option and the design is currently being progressed.

Feasibility work on the final solution is being progressed. The underground

solutions all present relatively few environmental effects, with the exception of

Option 4, which takes a longer route around the airfield, passing through a bat

corridor and landfill and in closer proximity to communities, increasing the risk of

adverse noise and air quality effects during the construction period.

Longford Substation

The replacement Longford substation is proposed as a variation of Option 1. The

preferred site is a vacant area, west of the existing railway and is not a registered

landfill site and therefore avoids the potential pollution constraints. Options 3 and 4

are further from the existing substation and would require more extensive

infrastructure works, causing disruption to neighbouring uses. Environmental

reasons were not the primary reason for discounting Option 2, which would require

the displacement of existing industrial tenants.

Wastewater treatment

Introduction

Heathrow currently discharges wastewater to the local Thames Water trunk sewer

network, which then conveys it to Mogden Wastewater Treatment Works (WWTW)

for treatment. The current network and treatment facilities do not have sufficient

capacity to meet the additional demands of an expanded Airport. New and

upgraded infrastructure must be provided to transfer and treat the wastewater

produced by increased numbers of passengers.

Heathrow is working closely with Thames Water and the Environment Agency to

develop a sustainable solution for the disposal of wastewater which not only



considers the requirements of Heathrow and the surrounding communities, but

also the wider environment and population in West London. Further detail is

provided in Document 4 Chapter 4 of the Updated SDR.

Options

Any increase in capacity will involve investment in new treatment and network

infrastructure and the upgrade of existing facilities. Following engagement with

Thames Water and development of other components, four options for providing

the additional wastewater treatment capacity required for the expanded Airport

have been considered:

1. Upgrade the existing treatment facilities at Mogden WWTW in west London

2. Upgrade the existing treatment facilities local to the Airport and divert some or

all flows to this treatment location

3. Construct a new WWTW local to the Airport to treat some, or all the flows from

the expanded Airport and surrounding communities

4. Discharge to local Thames Water sewers (the offset strategy).

The final solution could also involve a combination of these options.

Evaluation summary

The preferred option is to discharge to the existing sewer network (Option 4),

which avoids the requirement for land-take from around the Airport for a new

treatment facility, avoiding environmentally sensitive sites or the use of sites which

may displace other uses to more sensitive sites. By using the existing network, this

option is also a resource efficient solution (low energy and material use). Pumping

will, however, be required due to the scale of the Airport and its topography, which

make gravitational methods unfeasible. Other non-environmental reasons for

selection include the lower capital expenditure and operational and maintenance

costs. The preferred option relies upon a reduction in existing foul water flows

resulting from the displacement of residential and commercial buildings by the

airport expansion, however, should the results not support this option then it would

be necessary to progress with an alternative solution.

The alternative options which utilise a new or enhanced WWTW (Options 2 and 3)

would, however, provide other environmental benefits, namely the ability to use

the treated water for non-potable uses within the Airport, reducing water

consumption. This option has not been selected as the preferred option, however,

as the environmental benefits are considered to be outweighed by the need to

acquire additional land for the provision of a new facility and/or the expansion of

the existing, as well as the expenditure and operational issues associated with



running a treatment facility. Alternatively, the treated water from the WWTW could

be discharged into local watercourses which would also provide benefits to the

flows of local watercourses, for example the River Crane which is known to have a

low flow issues. These alternative solutions are being kept under review.

Home office immigration removals centre

Introduction

The expansion of Heathrow will result in the displacement of a number of existing

land uses, including the Harmondsworth and Colnbrook Home Office Immigration

Removal Centres (IRC).

A specific site selection process has commenced to investigate potentially suitable

locations for the replacement IRC, which has included engagement with the Home

Office. Further detail is provided in Document 4 Chapter 5 of the Updated SDR.

Options

The following locations for the IRC (shown in Graphic 3.17) were considered:

1. Site E1: Mayfield Farm

2. Site B1: Land east of M4 Spur

3. Site A4: Land at Holloway Lane

4. Site F1: Land to the south west of existing Airport boundary

5. Site D1: Airport Business Park.



Graphic 3.17: Indicative locations of IRC replacement options

Evaluation summary

All of the sites considered for the relocation of the IRC are constrained by

environmental designations and sensitive receptors. Airport Business Park (Option

5) was selected as the are there is considered to be greater opportunities to

mitigate potential effects and the site benefits from significantly greater support

from the Local Planning Authority than other sites.

The selected site is within the Green Belt and is constrained by two areas of Sites

of Importance for Nature Conservation and a graveyard that runs through the

middle of the site. Screening from adjacent uses would be required. The specific

location of the buildings will need to respond to these constraints and be located

sufficiently far south to minimise noise impacts on the facility as far as practicable.



The most preferred alternative, Option 1, also has a number of environmental

constraints. It is located within the Green Belt and an Archaeological Priority Zone

and is constrained by two areas of Scheduled Monument located at the eastern

and north-western corners of the site. However, it has good access to public

transport, is in close proximity to Airport gate, is available for early construction

and is further away from residential uses. The Local Planning Authority does not,

however, support the use of the site for the replacement IRC due to the potential

conflict with the aspirations of the draft Local Plan.

The other alternative sites considered are all within the Green Belt. Option 4 is

partially located within the Public Safety Zone and is in close proximity to Stanwell

Moor, a sensitive visual receptor. Options 2 and 3 are located to the north of the

airport further from public transport interchanges. Option 2 is partially covered by a

Site of Importance for Nature Conservation and the land is proposed for alternative

uses.

Airport supporting development

Introduction

Airport supporting development (ASD) is a term which is used to describe a range

of development that is related to the Airport’s operation, such as hotels, offices,

and warehousing. Those ASD facilities that represent the largest land take and are

likely to have the most significant environmental effects (car parking, cargo, MRO)

are set out separately in this chapter having been through the Scheme

Development Process separately.

In developing the preferred masterplan for land required beyond the expanded

operational Airport boundary the approach has been to consider three inter-related

land use components, namely:

1. Scale of land uses - what is the type and scale of ASD that may be generated

as a result of the Airport expansion and of this what should be brought forward

by Heathrow and what should be left for the market to deliver.

2. Location of land uses - what land parcels or sites may be appropriate to be

utilised to accommodate the identified scale of land use demand.

3. Zoning of land uses - what design and development principles should be set for

areas around the Airport to inform land use distribution principles and

subsequently the evolution of development zones.

Further detail is provided in Document 4 Chapter 7 of the Updated SDR.



Options

To facilitate the preferred masterplan development and determine the scale of

provision allowed for ASD, the Stage 2 and 3 process resulted in two alternative

land use scenarios:

1. Option 1: ‘Lean’ or low land use scenario – a strategy that minimises the scale

of ASD included in the DCO and leaves a larger quantum to be delivered by

the market, guided by the Heathrow Strategic Planning Group (HSPG) land

use policies in future local plans

2. Option 2: ‘Striving to Meet Demand’ or high land use scenario – inclusion of a

land use quantum and / or development sites that increases the quantum of

ASD delivered in the application for consent for development, leaving a lower

quantum to be delivered by the market. This would increase Heathrow’s control

over delivery and offers potential commercial benefits but might increase

planning risks on some additional quantum sites.

Graphic 3.18 shows the range of sites considered for ASD that met the initial

requirements and so were considered in the early stages of the process. Note that,

at this stage, all site boundaries were approximate and were based on the best

information available at the time. These would be subject to further work and

possible amendment.



Graphic 3.18: Indicative locations of ASD opportunity sites

Evaluation summary

Option 1, the ‘Lean’ land use strategy, has been selected as the preferred

strategy. This approach limits the number of sites that are required for

development when compared with the Option 2 and consequently reduces the

pressure on the use of sensitive sites, including those with formal environmental

designations and in close proximity to sensitive receptors.

The long list of sites proposed includes highly sustainable locations in close

proximity to sustainable transport routes. There are positive environmental

consequences associated with their use in comparison to alternative sites that are

not so well connected.

The proposed approach to ASD has been to locate hotels and offices along the

public transport spine and in areas with good connectivity to them such as Hatton

Cross or the Parkways to promote sustainable modes of transport.



The key alternative options would be to concentrate hotels within the Central

Terminal Area (CTA) and Western Landside Terminal Zone (WLTZ). This option

would reduce the need to occupy sensitive sites outside of the existing Airport

boundary, however phasing and physical constraints do not allow appropriate sites

to be readily available.

Industrial type uses were preferred in locations to the south of the Airport, in an

arch between Poyle Industrial Estate and Feltham Trading Estate, in close

proximity or adjacent to on and off airport cargo functions to create efficiencies by

clustering uses of similar nature. Alternative sites to the north and north east of the

airport are not preferred as these locations are more sensitive for trip generating

uses and are not favoured within the Surface Access Strategy.

Landscape Design and Green Infrastructure

Introduction

The landscape design and green infrastructure elements of the Preferred

Masterplan can be defined as a proposed network of new and enhanced hard and

soft landscape that mitigates the impact of the DCO Project on the natural and

historic environment, including landscape and visual amenity, and which forms an

integral part to health and quality of life of local communities.

Landscape design forms part of the Updated SDR (Document 4, Chapter 9), but

the evaluation of this component has followed a different path to the others. The

design response (quantum and distribution of Landscape Measures) has been

directly shaped by the requirements set out in the ANPS and this has not

fundamentally changed during the subsequent evolution of the Preferred

Masterplan but has been refined by, and has influenced the development of, other

components.

Refinements to the proposals should not result in materially different

environmental consequences on the basis that the purpose of the strategy

remains constant: to provide necessary mitigation for lost Public Open Space and

for effects on legally protected and notable species and biodiversity more

generally.

The constrained nature of the landscape surrounding the airport and the fact that

mitigation for effects on public open space or biodiversity designations must

typically be provided as close as practicable to the site of impact, also reduces

potential optionality.

The approach to landscape and green infrastructure design is also being informed

by historic environment principles which are detailed further within the Preferred

Masterplan document. Design refinement leading up to submission of the ES will



therefore be informed by the Heritage Design Strategy, which aims to provide a

positive contribution to the historic environment, which might benefit the

sustainable use of heritage assets. This is anticipated to include, for example, the

promotion of positive opportunities to sustain heritage assets through

diversification in use and the provision of pedestrian and cycling access that better

connects heritage assets to Public Open Space and other green spaces.

Earthworks

Introduction

Earthworks generally respond to and enable the construction of other components

(e.g. the runway, roads etc.) rather than comprising a component their own right.

As such, component level option evaluation was undertaken only for certain

aspects of the earthworks strategy, namely the identification of viable sources of

earthworks material to use in the DCO Project.

At a strategic level, the use of fill materials sourced from external projects (e.g.

Western Rail Link to Heathrow, HS2 etc.) was considered. However, due to

programme uncertainties, the required volume of materials and the likely effects of

haulage, borrow pits were identified as the preferred option.

Options have been considered for on-site and off-site borrow pits, which could

provide fill materials (e.g. sand and gravel) and prevent the need to acquire and

transport large volumes of material via the public highway. These sites must be

capable of transitioning from being a source of fill, to becoming new landfill once

excavation is complete. To avoid excessive haulage, options within 6-7km of

Heathrow, accessible via dedicated haul routes off the public highway, were

considered.

Options

The following sites for establishing borrow pits / landfill (shown in Graphic 3.19)

were considered:

1. Land within the order limits boundary to the immediate south of

Harmondsworth

2. Land to the immediate west of Sipson, partially within the order limits boundary

3. Land to the south of the M4 and west of the A312

4. Land to the east of Junction 13 of the M25, immediately adjacent the Staines-

Windsor rail line

5. Land to the south of Datchet, immediately west of the Staines-Windsor line



6. Land to the south of Brands Hill and Colnbrook, east of The Queen Mother

Reservoir

7. Land in-between Langley and Richings Park

8. Land south west of Iver, extending to the Great Western Main Line

9. Old Slade Lake (landfill only).

Graphic 3.19: Indicative locations of borrow pit site options

Evaluation summary

The selected option is a combination of Option 1 and Option 9, with an additional

land parcel to the west of Sipson kept under review (Option 2). Use of Old Slade

Lake would facilitate disposal of waste generated west of the M25, without the

need to cross the motorway. It would however result in adverse effects on surface

water. Option 1 has potential to adversely affect adjacent receptors in

Harmondsworth, due to the associated risk of noise, air quality and odour and

visual impacts. However, given proximity to the development boundary, it would



avoid the need to establish significant haul roads, falls within the proposed airport

boundary and is favourable from a cost perspective.

Option 3 was discounted due to the associated impacts on public open space at

Cranford Park and historic assets to the north. Borrow pits in this locality would

also rely on establishing a haul route close to residential receptors, including those

in Harlington, Sipson and Harmondsworth. The haul route would also need to

cross the M4 spur which would increase construction complexity, and costs.

Option 4 would result in the loss of habitat within the Staines Moor Site of Special

Scientific Importance (SSSI) and was subsequently discontinued. It would also rely

on haul routes crossing local roads near Stanwell Moor.

Given the location of Option 5 to the west of The Queen Mother Reservoir, it would

result in long haulage distances compared to the select option and demand routing

of construction traffic through residential areas, including Brands Hill and

Colnbrook. Associated haul routes would also need to cross the Windsor-Staines

rail line, increasing construction complexity and costs. This option was therefore

discontinued.

Option 6, as with Option 5, would route large volumes of construction traffic

through the Brands Hill and Colnbrook area and was similarly discontinued due to

the potential effects of establishing borrow pits in this area on local air quality.

Options 7 and 8 would result in adverse effects for a range of receptors, including

loss of agricultural land and habitat north of the M4. The associated haul routes

would also be required to cross the M4 and in the case of Option 8, the GWML

and Grand Union Canal. Option 7 would also potentially extinguishment the sports

and recreation facilities north of the M4. These options were therefore less

favoured than the selected option.

Construction Support Sites

Introduction

The DCO Project will require multiple Construction Support Sites (CSS) located on

or near to the periphery of the development boundary.

Heathrow has sought to keep construction activities within those areas identified

for permanent development as much as reasonably practicable. However,

construction activities need to be kept away from the active airfield and space is

tightly constrained in the main works areas themselves. There is subsequently a

requirement for temporary use of land during construction outside the permanent

boundary. Key requirements for CSS are set out below:

1. Provide sufficient land and space for necessary construction support functions



2. Located in close proximity to the main works sites

3. Provide access to the existing road and rail network (specifically the Rail

Freight area) and existing services and utilities infrastructure

4. Controlled access to the Airport boundary which will not impact existing airport

operations

5. Seek to avoid negative impacts on local communities and the environment

where reasonably practicable.

Rail Freight

In developing our construction proposals, the option of transporting materials and

delivering goods by water via the River Thames and / or the Grand Union Canal

has been considered. This is suggested as a possible mitigation measure by

ANPS paragraph 5.40. However, due to lack of water connectivity to the site and

the distance between the site and the nearest river / canal, this option is not

considered feasible.

The construction strategy is therefore based upon use of rail to transport materials

and goods to the construction site and in doing so this reduces potential vehicle

trips on the road network.

Options

The below sites were considered for the provision of a railhead facility to support

construction of the DCO Project:

1. Provision of a new railhead facility to the north-west of the third runway, parallel

to the northern boundary of the airfield, accessed by the existing spur

connecting with the Colnbrook railhead with the Great Western Main Line

(RF1)

2. Provision of a new railhead facility immediately east of and parallel to the M25,

approximately 1km south of Junction 14, accessed via a new spur off the

Staines-Windsor Line (RF2).

Evaluation summary

The selected option is to construct a new railhead facility to the north-west of the

third runway. This proposed site benefits from the existing connection to the

GWML, minimising the need for construction of additional rail infrastructure. The

site is located in close proximity to the Airport boundary and therefore facilitates

efficient transfer of materials from rail to within the main works area. Construction

of a railhead in this location will result in interaction with biodiversity receptors and

therefore appropriate mitigation will be required. Given the presence of historic



and authorised landfill in this locality appropriate management measures will be

implemented.

The site east of the M25 would locate the railhead facility itself immediately

adjacent to the Staines Moor Site of Scientific Interest, however the access spur

would result in the loss of habitat within this designation. As with the selected

option, this site would also result in interaction with historic and authorised landfill.

The southern part of the site extends into Flood Zone 2.

Other construction support sites

Beyond rail freight, other construction support site uses include load consolidation,

pre-fabrication and pre-assembly of structural elements, temporary parking for

staff and construction vehicles and contractor compounds, providing office space

and laydown areas. Further detail on the different activities which will be

conducted within CSS is provided in Document 4 Chapter 11 of the Updated SDR.

At the PEIR stage, these different uses have not been assigned to specific sites.

Instead, site options have been considered at a higher level based on their

suitability for one or preferably more of the activities set out above and within the

Updated SDR.

Options

The following options for provision of CSS (shown in Graphic 3.20) were

considered:

1. Land to the north and south of the existing A4 Bath Road and west of the M25

a. CS1 – between Brands Hill and Colnbook and south of the A4

b. CS2 – directly north of Poyle and south of the A4

c. CS13 – directly east of Brands Hill and north of the A4

2. Land north of the A4 Bath Road between the existing airport boundary and the

new third runway

a. CS4 – west of Polar Park

b. CS5 – east of Polar Park

c. CS6 – immediately west of Sipson Community Centre

d. CS7 – immediately west of Sipson

3. Land adjacent to the eastern boundary of the airport

a. CS8 – adjacent the existing Terminal 2 and 3 Long stay car park



b. CS9 – opposite the existing car park west of Hatton Cross station

4. Land south of the southern perimeter road/Horton Road

a. CS10 – north of Stanwell

b. CS11 – east of Stanwell Moor

c. CS12 – south of Poyle Industrial Estate

5. Land to the north of the proposed third runway

a. CS14 – north of Harmondsworth immediately south of the M4

b. CS15 – north east of Harmondsworth immediately south of the M4

c. CS16 – north west of Sipson

d. CS18 – north west of Sipson (between CS16 and CS16)

Graphic 3.20: Indicative locations of construction support site options

Evaluation summary

The evaluation of Options was primarily led by the delivery discipline, given the

criticality of CSS to the construction of the DCO Project. Given the complexity of

the construction programme, multiple CSS will be required to facilitate the wide

range of activities necessary to deliver the DCO Project. As such it was concluded



that the majority of the CSS considered are likely to be required, to ensure the

DCO Project can be delivered as efficiently and effectively as possible. The scale

and scope of works required prevents a single site being established to support all

construction activities. Instead, the requirement is for an even distribution of sites

around the periphery of the airport, to provide convenient access to multiple work

sites.

Of the land parcels north of A4 Bath Road (Option 2), CS6 was discounted on

environmental and community grounds. This site constitutes the Sipson

Recreational Ground. In addition to displacing this community facility, the risk of

adverse effects during construction would be increased given the site boundary is

adjacent to receptors within the village. This includes the effects of noise and

visual impacts, for example.

Whilst a combination of all options has been selected, the size of sites has been

reduced to manage risk of adverse environmental effects on adjacent receptors.

For example, this includes the land parcels under Option 1, where a buffer has

been included between the site boundary and receptors to the south within

Colnbrook. This approach has been adopted to increase separation between

construction activities and receptors and provide additional opportunities for

appropriate environmental measures. These include the use of noise barriers and

landscape screening as appropriate, to reduce potential noise and visual effects.

The risk of adverse air quality effects associated with construction traffic

movements and workforce travel was identified during the evaluation. The

construction strategy will be further refined between the PEIR and ES to identify

the most appropriate activities to be undertaken at each CSS. This will include

consideration of the measures contained within the Construction Traffic

Management Plan and Construction Workforce Management Plans to manage the

risk of adverse effects on transport users and local air quality during construction.

Documents

Heathrow Expansion PRELIMINARY ENVIRONMENTAL …...Jun 05, 2019 · Heathrow Airport, which is the Government’s preferred scheme”; “ The policies in the Airports NPS will have