TRANSPORT AND WORKS ACT 1992 Transport and Works ...... · Procedure) (England and Wales) Rules 2006 THE NETWORK RAIL (EAST WEST RAIL WESTERN SECTION PHASE 2) ORDER DRAFT ENVIRONMENTAL

TRANSPORT AND WORKS ACT 1992

Transport and Works (Applications and Objections

Procedure) (England and Wales) Rules 2006

THE NETWORK RAIL

(EAST WEST RAIL WESTERN SECTION PHASE 2) ORDER

DRAFT ENVIRONMENTAL STATEMENT

CHAPTER 11: GEOLOGY, SOILS AND LAND CONTAMINATION

Document Reference 133735-PBR-REP-EEN-

000009

Author Network Rail

Date June 2017

Date of revision and revision

number

June 2017

2.0

The Network Rail (East West Rail Western Section Phase 2) Order

Draft Environmental Statement

CONTENTS

11. GEOLOGY, SOILS AND LAND CONTAMINATION ......................................... 1

11.1 Introduction ........................................................................................................ 1

11.2 Limitations and Assumptions ............................................................................. 2

11.3 Legislation, Policy and Guidance ....................................................................... 5

11.4 Approach and Methodology ............................................................................. 14

11.5 Baseline Conditions ......................................................................................... 25

11.6 Assessment of Effects ..................................................................................... 59

11.7 Mitigation ....................................................................................................... 136

11.8 Residual Effects ............................................................................................. 137

LIST OF TABLES

Table 11.1 Local Planning Policies and Mineral Plans ............................................... 9

Table 11.2 Scoping Report Responses .................................................................... 16

Table 11.3 Estimation of the level of risk by comparison of consequence and probability ................................................................................................................. 19

Table 11.4 Defining the Sensitivity of Receptors ...................................................... 20

Table 11.5 Classification of Effects: Geology as a Resource (a) .............................. 21

Table 11.6 Significance Criteria: Physical Effects of the Project (b) ......................... 22

Table 11.7 Significance Criteria: Land Contamination Risk and Part 2A Status (c) . 23

Table 11.8 Significance criteria: waste soils and material re-use (e) ........................ 24

Table 11.9 Summary of Encountered Ground Conditions: Claydon Junction to Jarvis Lane, Bicester .......................................................................................................... 26

Table 11.10 Summary of Encountered Ground Conditions: Claydon Junction to Bletchley ................................................................................................................... 28

Table 11.11 Summary of Encountered Ground Conditions: Claydon Junction to Aylesbury ................................................................................................................. 29



Table 11.12 Summary of Potential Mineral Resources from Mineral Safeguarding Plans ........................................................................................................................ 30

Table 11.13 Summary of Geological Hazards by Project Sub-section ..................... 32

Table 11.14 Summary of Controlled Waters Receptors by Sub-section .................. 34

Table 11.15 Summary of Designated Ecological Sites by Sub-section .................... 38

Table 11.16 Off-Site Human Health Receptors ........................................................ 41

Table 11.17 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Cherwell District Council sub-section ........................................ 44

Table 11.18 Baseline Phase Conceptual Site Model Findings: Potential Contaminant Linkages within the Aylesbury Vale: Claydon/Quainton sub-section ........................ 45

Table 11.19 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Aylesbury Vale: Winslow/Swanbourne sub-section. ................. 47

Table 11.20 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Aylesbury Vale: Aylesbury sub-section ..................................... 49

Table 11.21 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Wycombe District Council sub-section. ..................................... 51

Table 11.22 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Milton Keynes Council sub-section ........................................... 53

Table 11.23 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Central Bedfordshire Council sub-section. ................................ 55

Table 11.24 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Bedford Borough Council sub-section ....................................... 57

Table 11.25 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Cherwell District Council sub-section .................................................................................................. 61

Table 11.26 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Claydon/Quainton sub-section ................................................................................. 63

Table 11.27 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Winslow/Swanbourne sub-section............................................................................ 65

Table 11.28 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Aylesbury sub-section .............................................................................................. 67



Table 11.29 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Wycombe District Council sub-section .................................................................................................. 69

Table 11.30 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Milton Keynes Council sub-section ............................................................................................................... 71

Table 11.31 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Central Bedfordshire Council sub-section .................................................................................................. 73

Table 11.32 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Bedford Borough Council sub-section .................................................................................................. 75

Table 11.33 Construction Phase Land Contamination Impact Assessment for the Cherwell District Council sub-section ....................................................................... 78

Table 11.34 Construction Phase Impact Assessment for the Aylesbury Vale: Claydon/Quainton sub-section ................................................................................. 80

Table 11.35 Construction Phase Impact Assessment for the Aylesbury Vale: Winslow/Swanbourne sub-section............................................................................ 83

Table 11.36 Construction Phase Impact Assessment for the Aylesbury Vale: Aylesbury sub-section .............................................................................................. 86

Table 11.37 Construction Phase Impact Assessment for the Wycombe District Council sub-section .................................................................................................. 89

Table 11.38 Construction Phase Impact Assessment for the Milton Keynes Council sub-section ............................................................................................................... 92

Table 11.39 Construction Phase Impact Assessment for the Central Bedfordshire Council sub-section .................................................................................................. 95

Table 11.40 Construction Phase Impact Assessment for the Bedford Borough Council sub-section .................................................................................................. 98

Table 11.41 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Cherwell District Council sub-section ................................................................................................ 103

Table 11.42 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Claydon/Quainton sub-section ............................................................................... 105

Table 11.43 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Winslow/Swanbourne sub-section.......................................................................... 107



Table 11.44 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Aylesbury sub-section ............................................................................................ 109

Table 11.45 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Wycombe District Council sub-section ................................................................................................ 111

Table 11.46 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Milton Keynes Council sub-section ............................................................................................................. 113

Table 11.47 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Central Bedfordshire Council sub-section ................................................................................................ 115

Table 11.48 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Bedford Borough Council sub-section ................................................................................................ 117

Table 11.49 Operational Phase Impact Assessment for the Cherwell District Council sub-section ............................................................................................................. 121

Table 11.50 Operational Phase Impact Assessment for the Aylesbury Vale: Claydon/Quainton sub-section ............................................................................... 122

Table 11.51 Operational Phase Impact Assessment for the Aylesbury Vale: Winslow/Swanbourne sub-section.......................................................................... 124

Table 11.52 Operational Phase Impact Assessment for the Aylesbury Vale: Aylesbury sub-section ............................................................................................ 126

Table 11.53 Operational Phase Impact Assessment for the Wycombe District Council sub-section ................................................................................................ 128

Table 11.54 Operational Phase Impact Assessment for the Milton Keynes Council sub-section ............................................................................................................. 130

Table 11.55 Operational Phase Impact Assessment for the Central Bedfordshire Council sub-section ................................................................................................ 132

Table 11.56 Operational Phase Impact Assessment for the Bedford Borough Council sub-section ............................................................................................................. 134



Volume 2 Chapter 11 Page 1

11. GEOLOGY, SOILS AND LAND CONTAMINATION

Summary

Baseline

The Project Area is largely active railway surrounded by rural and residential land uses. A section of the Project is disused railway. There are a number of potential sources of contamination, including active and historic landfills within 500 m of the Project Area. Superficial Alluvial and River Terrace Deposits are localised Secondary A aquifers. A small portion of the Project overlies a Principal aquifer. Numerous surface water courses pass beneath the route. There are no significant areas of potential ground instability, and limited economic mineral resource potential.

Effects

The assessment found that with incorporated mitigation the ground conditions (including stability) and contamination effects are assessed as neutral and not significant.

Mitigation

No additional mitigation measures beyond those required under legislative and best practice have been identified.

Residual Effects

No residual effects are anticipated.

11.1 Introduction

11.1.1 This chapter of the Draft ES identifies and assesses the effect of the

Project on geology, soils and land contamination. The potential effects of

the Project on surface and groundwater, including flooding, are covered in

detail in Chapter 13 (Water Quality and Flood Risk).

11.1.2 The assessment of the geology, soil and land contamination effects of the

Project covers the shorter term effects during construction and the longer

term effects arising from the operation of the Project. The Department for

Communities and Local Government (DCLG) ‘Environmental Impact

Assessment: A guide to good practice and procedures’275 identifies the

following effects which may be relevant to the assessment of a

development on geology, soils and/or land contamination:

275

http://webarchive.nationalarchives.gov.uk/20120919132719/www.communities.gov.uk/documents/planningandbuilding/pdf/151087






(a) Effects of the Project on geology as a resource, e.g. loss of or damage to Local Geological Sites276, geological sites of special scientific interest (SSSIs) or mineral resource sterilisation;

(b) Physical effects of the Project, e.g. ground stability;

(c) The potential for existing ground contamination to be mobilised, the addition of pathways for migration and/or additional receptors, or effects associated with the potential for polluting substances used (during construction/operation) to cause new ground contamination issues on site, e.g. introducing/changing the source of contamination;

(d) Effects on land use/resources, e.g. quantity and quality of agricultural soils taken, effect on surrounding land uses, loss of greenfield land; and

(e) Impacts associated with re-use of soils and waste soils, e.g. re-use of site-sourced materials on-site or off-site, disposal of site-sourced materials or importation of materials to the site.

11.1.3 In order to assess the effects set out above, this chapter assesses the

effects of the Project on geology and mineral resources (a), physical

effects (b), the potential for contamination to be introduced to the

environment or mobilised as a result of the works (c), and effects

associated with the re-use of soils and waste soils (e). Some of these

effects may be managed through the incorporation of embedded

mitigation measures; this is discussed in Section 11.2.

11.1.4 The assessment of effects on soils in use for agricultural purposes (d) is

discussed within Chapter 6 (Land Use and Agriculture). The detail of

material importation/re-use is not covered in this chapter. Chapter 2

(Project Description) sets out more information about how the Project will

approach waste management.

11.2 Limitations and Assumptions

11.2.1 General limitations to assessments within the Draft ES are outlined in

Chapter 4 (EIA Methodology) Section 4.11. With regard to Geology, Soils

276 Government guidance uses the term Local Sites for non-statutory sites, as distinct from the Sites of Special Scientific Interest [SSSIs] which are protected by government statute. The term Regionally Important Geological/geomorphological Sites (RIGS) has been in usage now for many years and is still used to describe Local Geological and should be regarded as synonymous. (http://wiki.geoconservationuk.org.uk/index.php5?title=Main_Page).




and Land Contamination the following limitations were encountered during

the process of collating baseline information and undertaking the

subsequent assessment:

Intrusive investigation has been undertaken across the Project; however restrictions on third party land access have resulted incomplete coverage of the Project Area. The focus and design of the investigation was also geotechnical which has further limited the usefulness of the data gathered in relation to contamination; and

Groundwater gauging and sampling of the installed wells has yet to be undertaken.

11.2.2 In order to ensure a robust assessment, the following assumptions have

therefore been incorporated into the assessment of the Project:

Members of the public will have no direct access to the Project Area during construction works (thereby reducing the likelihood for human health exposure to potentially contaminated materials); and

Construction best practice will be adhered to at all times during the works.

11.2.3 It should be noted that the risk assessment and impact assessments have

been carried out predominantly using desk-based information, i.e. a

qualitative assessment. Though informative these assessments are

unavoidably high level. Risks such as the potential for ground gas

migration to impact the works and for groundwater receptors to be

impacted as a result of piling works proposed within the Project can only

be appropriately assessed by undertaking further targeted intrusive

ground investigation.

11.2.4 Groundwater gauging and sampling of the installed monitoring wells will

be undertaken in the vicinity of key areas of proposed earthworks.

Ground gas monitoring will also be carried out in key risk areas. Piling risk

assessments must also be undertaken in line with the requirements set

out within the desk study in order to fully characterise and mitigate the

risks to groundwater.

Embedded Mitigation

11.2.5 In relation to soils, geology and land contamination, measures considered

to be ‘construction best practice’ are integral to the Project’s construction.




The Code of Construction Practice (CoCP) for the Project will set out and

deliver the measures to be implemented during construction. A draft

CoCP is appended to this Draft ES. In relation to geology, soils and land

contamination, these measures will be:

Areas of contamination will be identified and remediated by specialist contractors prior to general construction access;

Construction workers will be provided with appropriate Personal Protective Equipment (PPE) and informed by risk assessment to limit their exposure to contamination;

Hand washing facilities will be made available to site operatives, site rules will be created insisting on hand washing prior to breaks and at the end of the working day, and eating and drinking will be limited to site welfare facilities during agreed break periods;

Provision of specific dust mitigation measures will be implemented;

The work area will be well delineated and kept secure to prevent trespass;

Silt mitigation measures will be implemented to limit runoff of exposed soil into watercourses. Bunds, cut-off ditches, settlement ponds and drainage covers will be utilised to limit runoff from entering watercourses;

Spill kits and plant nappies will be provided for all static plant and equipment;

Environmental awareness training will be provided and documented to all staff working on the Project, including daily site briefings (Toolbox Talks);

Re-fuelling will be via a mobile bowser (storage and supply tank)

equipped with a full spill kit and bunding. No refuelling will take place within 10 m of a water course or receptor;

A procedure will be included within the CoCP to manage previously-unidentified contaminated material that is encountered during the works;

Storage areas for materials will be identified, and surplus soil arisings from levelling or excavation works that demonstrate visual or olfactory evidence of contamination will be stored in covered skips, or on a sheeted stockpile placed on hardstanding or sheeting pending its removal or treatment; and

The intrusive investigation to characterise ground conditions will incorporate an assessment of the ground aggressivity which will inform the design of the Project. Further specific intrusive investigation will likely be required prior to the commencement of construction.




11.2.6 The assessment of likely significant effects during construction therefore

takes into account implementation of these mitigation measures. During

the operational phase further mitigation measures are embedded into the

design of the Project, such as an improvement of drainage infrastructure

and the removal/remediation of contaminated arisings encountered

following the construction phase.

11.3 Legislation, Policy and Guidance

11.3.1 National and local policy and guidance considered within this assessment

are detailed below. The list is not intended to be exhaustive, but includes

the main documents relating to the protection, preservation and, where

appropriate, enhancement of the geological environment.

Legislative Framework

11.3.2 The legislative framework applicable to this assessment is summarised as

follows:

Part 2A of the Environmental Protection Act 1990 (as amended)277;

the Environment Act 1995278;

The Control of Substances Hazardous to Human Health Regulations 2002 (as amended) (COSHH Regulations)279;

The Water Environment (Water Framework Directive) (England and Wales) Regulations 2003280;

Dangerous Substances Directive (Amendment) 2006281;

Environmental Damage and Liability (Prevention and Remediation) Regulations 2009282;

The Environmental Permitting (England and Wales) Regulations 2010283;

Environmental Permitting Regulations 2016284;

277 HMSO (1990) Part 2A of the Environmental Protection Act, 1990

278 HMSO (1995) Environment Act, 1995

279 SI 2002/2677 (as amended)

280 SI 2003/3242

281 SI 2006/3311

282 SI 2015/810

283 SI 2010/675 (as amended)

284 SI 2010/675 (as amended)




Waste Framework Directive 2008;

Waste (England and Wales) (Amendment) Regulations 2012;

Landfill Regulations285, which implement the requirements of the Landfill Directive (99/31/EC);

Hazardous Waste Regulations286;

Control of Asbestos Regulations 2012287;

Contaminated Land (England) (Amendment) Regulations 2012288; and

Construction (Design & Management) Regulations 2015 (CDM Regulations)289.

Land Quality and Contamination

11.3.3 Part 2A establishes a legal framework for dealing with land contamination

in the UK. It provides a means of dealing with unacceptable risks posed

by land contamination to human health and the environment. Government

objectives with respect to land contamination policy and the Part 2A

regime are set out in the Department for Environment Food and Rural

Affairs (Defra) Contaminated Land Statutory Guidance 2012290 as:

To identify and remove unacceptable risks to human health and the environment;

To seek to ensure that contaminated land is made suitable for its current use; and

To ensure that the burdens faced by individuals, companies and society as a whole are proportionate, manageable and compatible with the principles of sustainable development.

11.3.4 The Contaminated Land regime as set out in Part 2A of the Environmental

Protection Act 1990, secondary legislation291 and relevant guidance292,

does not address potential risks to construction or maintenance workers

or other occupations which may have direct exposure to contaminated

285 SI 2002/1559

286 SI 2005/894

287 SI 2012/632

288 SI 2012/263

289 SI 2015/51 290 Department for Environment Food and Rural Affairs. Environmental Protection Act 1990: Part 2A. Contaminated Land Statutory

Guidance. April 2012.

291 Contaminated Land (England) Regulations 2006 (SI 2006/1380) and Contaminated Land (Wales) Regulations 2006 (SI 2006/2989), which include details of grounds for appeal and when land should be designated as a special site, and Radioactive Contaminated Land (Modification of Enactments) (England) Regulations 2006 (SI 2006/1379).

292 Defra: Contaminated Land Statutory Guidance (April 2012).




land. The risks to these human receptors are managed through health

and safety legislation, such as the COSHH Regulations and the CDM

Regulations which require the employer to carry out an assessment of the

risks associated with exposure to hazardous substances and then to

prevent those risks, and, if this is not reasonably practicable, to

adequately control such exposures.

Waste Soils and Materials Re-use

11.3.5 The Waste Framework Directive 2008 (WFD 2008)293 establishes the

legislative framework for the management, recovery and disposal of

waste. It also provides a definition of waste as “any substance or object

which the holder discards or intends or is required to discard.”

11.3.6 The most recent revisions to the WFD 2008 are transposed in England

and Wales through the Waste (England and Wales) (Amendment)

Regulations 2012. Accordingly, where uncontaminated soils and other

natural materials (for example, rock) are excavated during earthworks and

it is proposed to re-use them in the construction of the Project, then these

materials would fall outside the definition of waste and so outside the

waste management regime.

11.3.7 The WFD 2008 specifically excludes from its scope “uncontaminated soil

and other naturally occurring material excavated in the course of

construction activities where it is certain that the material will be used for

the purposes of construction in its natural state on the site from which it

was excavated.”

11.3.8 Material that is surplus to requirements or needs to be discarded (e.g. due

to its engineering properties or contamination) is strictly classified as

waste and should be disposed of in accordance with waste duty of care

requirements, including the Landfill Regulations294, Hazardous Waste

Regulations295 and publication WM3296.

293 2008/98/EC

294 SI 2002/1559

295 SI 2005/894

296 Environment Agency (2015). Hazardous Waste Classification – Guidance on the classification and assessment of waste.




11.3.9 Re-use of materials on site can be managed through either the

Environmental Permitting Regulations 2016297 (EPR) or in accordance with

the guidance provided in the Contaminated Land: Applications in Real

Environments (CL:AIRE) Code of Practice Definition of Waste: Code of

Practice (CoP)298.

11.3.10 Inert excavated material can be re-used without consent, providing that

the works for which it is used are part of the development design and

approved under planning consents. Under the CL:AIRE CoP, materials

excavated on-site are not deemed to be waste if it can be demonstrated

that they are suitable for re-use within the development, subject to the

relevant assessment, the preparation of a Materials Management Plan

and a declaration by a CL:AIRE Qualified Person.

National Planning Policy

National Planning Policy Framework (2012)

11.3.11 The National Planning Policy Framework (NPPF)299 sets out the

Government’s interpretation of the planning system and identifies main

policy objectives and principles. With regard to development of land, the

NPPF states that Local Planning Authorities should take into account the

nature, scale and extent of contamination which may pose risks to health,

the natural environment and the potential sensitivity of the area or

proposed development. In order to achieve these objectives the

Government aims for every local authority in England to draft and adopt a

local plan. The plans set out local planning objectives, policies and identify

how land is currently utilised. These plans are developed in consultation

with local communities and provide a framework by which proposed

developments are assessed by planning officers with regard to the

requirements of local populations/infrastructure. Local plans are therefore

compiled to ensure that when assessing developments:

297 SI 2010/675 (as amended)

298 CL:AIRE (2011) The Definition of Waste: Development Industry Code of Practice.

299 Department for Communities and Local Government (2012) National Planning Policy Framework




The natural and local environment are protected and enhanced, including protection and enhancement of valued landscapes, geological interests and soils, remediating and mitigating despoiled, degraded, derelict, contaminated and unstable land (Paragraph 109);

To prevent unacceptable risks from pollution and land instability planning policies and decisions should ensure a development is appropriate for its location (Paragraph 120);

Sites are suitable for their proposed new use, taking account of ground conditions and land instability, including from natural hazards or former

activities. Once developed, the land should not be capable of being determined as Contaminated Land under Part 2A (Paragraph 121); and

11.3.12 Mineral resources should be protected from development through the

formulation of mineral safeguarding areas (Paragraphs 142 and 143).

Local Planning Policy

11.3.13 Local planning policies for the Project Area have been reviewed as part of

this assessment and are listed in Table 11.1. The local core mineral

strategies have also been reviewed identifying mineral safeguarding areas

adjacent to the Project Area.

Table 11.1 Local Planning Policies and Mineral Plans

Relevant Local Planning Policies/Mineral Strategies

Local Authority Sub-section

Adopted Cherwell Local Plan 2011 -

2031 (July 2015)

Cherwell District Council

The Oxford Minerals and Waste Core

Strategy (August 2015)

Adopted Aylesbury Vale District Local

Plan (January 2004)300 Aylesbury Vale: Claydon/ Quainton;

Winslow/Swanbourne and Aylesbury

Wycombe District Council (WDC) (subject

to Buckinghamshire Mineral strategy) The Buckinghamshire Minerals and

Waste Core Strategy (November 2012)

The Milton Keynes Local Plan (2005)301

The Milton Keynes Core Strategy

(2013)

Milton Keynes Council

300 The Vale of Aylesbury Local Plan is currently being reviewed following closure of the public consultation period in

September 2016.

301 The Milton Keynes Local Plan (referred to as Plan:MK) is under preparation at the time of writing following closure of the

consultation period in April 2016.




Relevant Local Planning Policies/Mineral Strategies

Local Authority Sub-section

Milton Keynes Minerals Local Plan

2001 – 2011 Adopted (April 2006)302 Milton Keynes Council

The Central Bedfordshire Core

Strategy (2009 – 2026) (2009)

Central Bedfordshire Council,

Bedfordshire Borough Council Bedford Borough, Central

Bedfordshire and Luton Borough

Council Minerals and Waste Local Plan

(2014)

The Wycombe District Local Plan

(2004)303

The Wycombe Core Strategy (2008 –

2026)

Wycombe District Council

Adopted Cherwell Local Plan 2011-2031 (July 2015)

11.3.14 The Cherwell Local Plan states that the Cherwell District Council (CDC)

has a number of key challenges to ensuring sustainable development

such as “a need to ensure that contamination is addressed effectively on

sites through re-development”. Policy ESD10 states that during

development “the reuse of soils will be sought”. Policy ENV12

encourages development to occur on brownfield land.

The Oxford Minerals and Waste Core Strategy (2015)

11.3.15 Policy M9 requires that “mineral infrastructure that supports the supply of

minerals in Oxfordshire is safeguarded against development that would

unnecessarily prevent the operation of the infrastructure or would

prejudice or jeopardise its continued use by creating incompatible land

uses nearby.”

Adopted Aylesbury Vale District Local Plan (AVDLP) (2004)

11.3.16 In 2007 the policies contained within this plan ceased to be in effect

unless saved by a Direction from the Secretary of State. The new Vale of

Aylesbury Local Plan (VALP) has yet to be adopted. No policies relevant

to this assessment were saved from the AVDLP.

302 The updated Milton Keynes Minerals Local Plan was submitted to the Secretary of State for review in March 2016.

303 An updated Wycombe District Local Plan to cover the period up to 2033 is currently in preparation.




The Buckinghamshire Minerals and Waste Core Strategy (2012)

11.3.17 Strategic Objective 03 of the Buckinghamshire Minerals and Waste Core

Strategy Development Plan is “to protect the county’s mineral resources

within the Thames Valley, where the richest deposits of sand and gravel

are to be found and potentially viable resources in north Buckinghamshire

from development which would prevent their future use.”

Adopted Milton Keynes Local Plan (2005)

11.3.18 Milton Keynes Council (MKC) is currently preparing a new local plan for

the Borough called Plan:MK, although it has yet to be finalised and

adopted. Only those policies saved from the Milton Keynes Local Plan are

currently adopted. The following policy relevant to this chapter has been

saved from the previous Local Plan; NE3 states that “all new development

should incorporate proposals to enhance geological features and where

possible compensate for impacts on the immediate area and site

characteristics.”

Milton Keynes Minerals Local Plan (April 2006)

11.3.19 Policy MLP4 states that the planning authority “will not permit

development proposals that would cause sterilisation of mineral deposits

on the proposed development site, or which prejudice the future working

of minerals on adjacent sites.”

11.3.20 There are three exceptions to this policy which are:

The mineral deposit is not currently commercially viable and is unlikely to be in future;

There is a case in favour for allowing the proposed development to proceed without prior extraction of the mineral; and

Extraction of the mineral would be subject to strong environmental or other objections making it highly unlikely to be permitted.

The Central Bedfordshire Core Strategy (2009)

11.3.21 Policy CS18 states that the council will:

“Support the designation, management, and protection of biodiversity and

geology including national designations (SSSIs), locally important County




Wildlife Sites (CWSs) and Regionally Important Geological and

Geomorphological Sites (RIGGS304); as well as those local priority habitats

and species identified in the Local Biodiversity Action Plan.”

Bedford Borough, Central Bedfordshire Minerals and Waste Local Plan (2014)

11.3.22 The Plan states that most development proposed within a mineral

safeguarding area will be subject to Mineral Strategic Policies (MSP) 11

and 12. MSP 11 requires that a Mineral Resource Assessment be

undertaken by a suitably qualified professional, which establishes through

site specific geological survey data, the existence or otherwise of a

mineral resource of economic importance. MSP 12 outlines the

circumstances under which mineral extraction will be permitted.

The Wycombe Local Plan (2004)

11.3.23 Saved policy RT19 includes the following guidance in paragraph 12.61

“Development proposals must also take particular regard of the ground

conditions and its stability due to mineral extraction and landfill activities in

the area.”

Building Control

11.3.24 Any construction work resulting in the creation of a structure is subject to

Building Control under the Building Regulations (2010)305. Requirement

C1. (2) states:

“Reasonable precautions shall be taken to avoid danger to health and

safety caused by contaminants on or in the ground covered, or to be

covered by the building and any land associated with the building”.

11.3.25 Contamination in the ground has the potential to attack and weaken

building materials which may consequently lead to a breach of Part A of

these Regulations which relate to structural safety. The following

approach is proscribed to address ground contamination:

304 Regionally Important Geological Sites (RIGS) and Regionally Important Geological and Geomorphological Sites (RIGGS)

are synonymous

305 HM Government (2010) The Building Regulations: Site preparation and resistance to contaminants and moisture C.




Site investigation should be carried out to determine the extent and nature of any contamination;

Any ground covered by a building must be free from any material that might damage the building or affect its stability;

Reasonable precautions must be taken to avoid danger to health and safety caused by contaminants on or in the ground covered by a building or any land associated with that building; and

Precautions must be taken against ground gases such as landfill gases, radon, vapours etc.

Additional Guidance

11.3.26 The following additional guidance documents relevant to geology and

soils, and contaminated land have been considered when undertaking this

chapter:

The Design Manual for Roads and Bridges (DMRB) was utilised, which is a guidance document produced by Highways England (Volume 11, Section 2, Part 5 Assessment and Management of Environmental Effects, August 2008);

DMRB Volume 11, Section 3, Part 11 Geology and Soils, June 1993;

Contaminated Land Report (CLR) 11: Model Procedures for the Management of Land Contamination, produced jointly by the Environment Agency and Defra 2004;

Department of the Environment (DoE) – Industry Profiles for previously developed land, Environment Agency, 1995;

Construction Industry Research and Information Association (CIRIA) C552 – Contaminated Land Risk Assessment – A Guide to Good Practice 2001;

CIRIA C665 – Assessing Risks Posed by Hazardous Ground Gases to Buildings,2007;

CIRIA C681 – Unexploded Ordnance (UXO) – A Guide for the Construction Industry, 2009;

CIRIA C733 - Asbestos in Soil and Made Ground: A Guide to Understanding and Managing Risks, 2014;

CIRIA C682 – The Volatile Organic Contaminants (VOCs) Handbook, 2009;

Environmental Impact Assessment: A guide to good practice and procedures, Department for Communities and Local Government, June 2006; and

British Standards (BS) 10175:2011 (A1:2013) – Code of Practice for Investigation of Potentially Contaminated Sites.




11.4 Approach and Methodology

11.4.1 The approach to the assessment comprises:

Establishing the baseline conditions for the area of study with respect of, but no limited to geology, mineral resources, regionally important geology sites (RIGs), ground stability, soils, hydrology, hydrogeology, contaminated land (including the potential for unexploded ordnance and ground gases) and historical uses supplemented in some areas by intrusive investigation;

Identification of potential impacts on identified resources and receptors, such as local geological sites, from the construction and operational phases;

Assessment of the significance of likely effects from the Project;

Identification of potential measures for mitigating any likely significant effects resulting from the Project; and

Identification of any residual effects.

Establishing the Baseline

11.4.2 The baseline has relied on existing data, reports, and historic records.

The following sources have been reviewed:

Environmental data from Landmark Envirocheck report (April 2015);

Historical mapping at scales of 1:10,000 and 1:2,500 from publically-available mapping sources to identify former industrial or similar land uses with the potential to cause residual land contamination or indicate possible ground stability issues, or areas of geological significance such as a mineral resources which could at some point be subject to extraction, or features which demonstrate an educational value;

Local Authority mineral plans, which set out the planning framework for future mineral extraction and associated development were used to identify ‘mineral safeguarding areas’ which could potentially be affected by the Project;

Local geology groups were contacted to identify regionally important geological sites (RIGs) also known as local geology sites which are sites designated for their importance in terms of geology or geomorphology. They are not afforded the statutory management protection enjoyed by SSSIs;

Existing risk assessment reports regarding the potential risk from unexploded ordnance;

Preliminary consultation advice from the Environment Agency, local authorities and other regulatory agencies from the Scoping Opinion responses in respect of potential impacts to ground conditions; and




A series of ground investigation reports have been consulted in order to obtain high-level ground conditions information such as geological succession and the presence/absence of significant thicknesses of Made Ground306.

11.4.3 During operation, HS2 is considered part of the Operational Baseline, so

has not been considered cumulatively.

Spatial Scope

11.4.4 The definition of the study area takes into account the transport and final

location of potential contaminants of concern in the environment, and the

connectivity of these contaminants via pathways of migration/exposure to

the receptors identified. A 500 m zone from the site boundary is

commonly used for the initial consideration of potential land contamination

and associated potential risks for schemes such as this, where

contamination is generally historic and likely to be of limited lateral

mobility307. If the presence of mobile contaminants and migration

pathways is confirmed, then the area subject of study may be extended to

identify additional receptors. Based on the land quality baseline

information compiled for the Scoping Report, the extension of the area

subject of study beyond 500 m from the Project Boundary was not

considered necessary. The Project drawings show a 250 m buffer zone

from the Project Boundary, which is the most critical area for identification

of potential sensitive receptors and sources of risk such as contamination

or areas of ground instability.

11.4.5 The only exception to this buffer zone was when considering ecological

receptors. A maximum 1 km lateral ‘buffer’ zone was selected from the

Project Boundary in this instance to incorporate the risks of ecological

receptors travelling beyond identified habitats.

306 Made Ground is described by the BGS as “artificial ground, often previously developed, associated with potentially

contaminated material, unpredictable engineering conditions and unstable ground”.

307 During the Scoping stage, baseline information was reviewed in order to confirm potential contamination sources and

sensitive receptors, and 500 m was judged to be sufficient to capture potential effects given the particular environment setting of the Project.




Temporal Scope

11.4.6 The assessment considered the potential impacts and associated

significance of effects at the following stages:

The construction phase (2019); and

The operational phase (2024).

Consultation

11.4.7 Following issue of the Scoping Report, feedback was received from

stakeholders with regard to the scope of the assessment. These are

detailed in Table 11.2, alongside a response to each comment. Where

respondents made duplicate comments these are included once in the

table.

Table 11.2 Scoping Report Responses

Consultee Consultee comment Technical team response

Department for

Transport (DfT)

Groundwater and surface water

monitoring of Project requested

– including hydrocarbon testing

Groundwater gauging and

sampling not yet undertaken for

Project – additional intrusive

ground investigation is planned,

and this will be included as part

of that scope, in line with the

Compliance Assurance Quality

requirements under the Landfill

Directive.

EWR

Consortium Local geological sites should be

included as sensitive receptors

Local Geology Groups were

contacted to determine if any

such sites were in the vicinity of

the Project

Environment

Agency

Requested a detailed

investigation of each historic

and active landfill

The ground investigation scope

was confined to the Project

Area.

Requested consultation and

input into proposed drilling

methods to avoid creation of

preferential pathways for

contaminant migration

This will be addressed in

subsequent phases of intrusive

investigation, to be undertaken

in consultation with regards to

the GI design.




Consultee Consultee comment Technical team response

Environment

Agency

Concern about impacts on

existing landfills at Stewartby

and Bletchley regarding

potential impacts to leachate

and gas management systems.

Letter drafted to landfill

operators and a meeting

undertaken with Environment

Agency - additional

consultation/risk assessment

required when works to be

undertaken on or in vicinity of

landfilled material and to define

the GI design.

11.4.8 To collect data relevant to the assessment, local authority members of the

EWR Consortium were consulted via email on 3 September 2015.

Responses were received from Wycombe District Council (WDC),

Aylesbury Vale District Council (AVDC) and Bedford Borough Council

(BBC). WDC and AVDC provided site investigation reports. BBC noted

that they held no relevant information.

11.4.9 Regular meetings with the Environment Agency have taken place to

discuss relevant issued posed by the Project. A meeting was held at the

Environment Agency Wallingford office on 8 December 2015 at which

they requested that their investigated site data was included in the

baseline. A shape file for mapping was provided which was reviewed,

however no detailed information was included. A factual summary of

Environment Agency investigated sites in the vicinity of the Project Area

has been included within the desk studies, which can be found in

Appendix (11.1).

11.4.10 The operators of landfills in the immediate vicinity of the Project were

consulted via letter in order to obtain background information on ground

conditions adjacent to the Project. No response was received from any of

these operators prior to the preparation of this Draft ES.




Methods

11.4.11 The method of assessing the potential impacts of the Project on geology,

soils and land contamination were carried out in two stages.

Stage 1: Risk Assessment

11.4.12 The approach for the risk assessment was based on Environment Agency

guidance document CLR11308 and the DCLG guidance on EIA. These

documents provide a technical framework for the application of a risk

management process through the following steps:

Preliminary Conceptual Site Model (PCSM): A desk study review of available information, including existing ground investigation data within the area of study, was undertaken to complete a PCSM, identifying potential hazards/sources, migration or exposure pathways and receptors relevant to the area subject of study, as well as potential geo-environmental hazards. A Conceptual Site Model (CSM) will be developed once further GI has been completed at the detailed design stage, when more site-specific information is available and the PCSM can be updated.

Risk assessment: A qualitative risk assessment has been carried out and is presented within this ES chapter using desk-based information only, on the basis of the PCSM. Where risks are identified, these will be appropriately mitigated through design and/or the development of a remediation strategy and its subsequent validation as necessary. The residual risks are determined and assessed based on the likelihood and consequence of their realisation. Once further GI data is available, generic quantitative risk assessments (GQRA) for human health and controlled water receptors will be undertaken.

11.4.13 The risk assessment used a methodology based on guidance provided in

CLR11308 and R&D66309 which provides direction on the development and

application of the consequence and probability matrix (see Table 11.3) for

contaminated land risk assessment.

308 Environment Agency. 2004. Model Procedures for the Management of Land Contamination. CLR11.

309 NHBC & Environment Agency. R&D 66




Table 11.3 Estimation of the level of risk by comparison of consequence and

probability

Consequence

Severe Medium Mild Minor P

rob

ab

ilit

y

(Lik

elih

oo

d)

High

Likelihood Very high risk High risk Moderate risk Moderate /

low risk

Likely High risk Moderate risk

Moderate /

low risk Low risk

Low

Likelihood Moderate risk Moderate /

low risk Low risk Very low risk

Unlikely Moderate /

low risk Low risk Very low risk Very low risk

11.4.14 Definitions of probability, consequence and the classified risks (as given in

R&D66) adopted for this assessment are provided in Appendix 11.2.

Stage 2: Impact Assessment

11.4.15 The impact assessment was completed by comparison of the baseline

condition to both the construction and operational phase risk assessments

of the Project to determine the change in risk profile. The impact

assessment included those mitigation measures considered to be

embedded. The changes in contamination status are described as

positive, neutral or negative, and consideration is made of whether they

are major, moderate or minor (on the basis of the area over which the

effect may occur), duration (short, medium or long term) and whether the

effect is permanent or temporary. Appendix 11.2 presents an explanation

of these criteria.

11.4.16 In addition to the above, a value has been assigned to each of the

receptors with respect to its value and/or sensitivity. The definition of

each of these is given in Table 11.4. The value of a receptor is

considered when determining consequence or an effect in the risk

assessment.




Table 11.4 Defining the Sensitivity of Receptors

Value Criteria Examples

Very high

Very high importance / rarity;

international significance and very

limited opportunity for replacement.

Principal aquifer providing

potable supply to a large

population, within a

groundwater Source

Protection Zone (SPZ) 1. SPZ

are buffer zones defined by

the Environment Agency to be

protective for identified

groundwater sources such as

wells or boreholes.

Water Framework Directive

(WFD) high status surface

water body providing potable

supply to a small population.

Sensitive human health

receptors, e.g. young children.

Sterilisation or loss of

strategically-important mineral

resources.

Creation of ground instability

(on- or off-site)

Loss of potential for materials

re-use

High High importance and rarity; limited

opportunity for substitution.

Principal aquifer beyond a

SPZ, or a Secondary aquifer.

WFD good status surface

water body which implies that

the water body possesses a

good biological quality (a

diverse composition of

invertebrates), a good

hydromorphological quality -

measured elements include

river continuity, channel

patterns, and a good physico-

chemical quality- measured

elements include pH,

oxygenation, temperature and

concentrations of specific

pollutants. Surface waters can

be classified as good,

moderate, poor and bad

based upon an assessment of

these characteristics.

Less sensitive human

receptors, e.g. construction

workers using PPE.




Value Criteria Examples

Loss of a significant proportion

of a regionally-important

mineral resource.


(on-site structures affected)

Reduced potential for

materials re-use.

Medium

High or medium importance and

rarity, regional scale, limited

opportunity for substitution.

Secondary aquifer providing

abstraction of water for

agricultural or industrial use.

WFD moderate status.

A moderately economically

viable mineral resource.


Minimal potential for materials

re-use.

Low Low or medium importance and

rarity, local scale.

Unproductive strata

(groundwater) are rock layers

of a low permeability which do

not contribute significantly to

river base flow or water

supplies.

WFD poor status.

No economically viable

minerals.

No changes to ground

stability.

No opportunity for material re-

use.

11.4.17 The classification of effects has been based on the criteria defined in

Table 11.7, and Table 11.5.

Table 11.5 Classification of Effects: Geology as a Resource (a)

Classification Effect

Major adverse

Loss of or major damage to a site designated due to its geological

attributes such as an SSSI including land take/ destruction of

distinctive geological features. Significant sterilisation of mineral

resources from an identified mineral safeguarding area such that it

is unavailable for development by future generations.





Moderate

adverse

Moderate damage to the amenity of a site designated due to its

geological attributes such as an SSSI. Moderate sterilisation of a

mineral resource from identified mineral safeguarding area.

Moderate damage to local geology sites and RIGs.

Minor adverse

Minor damage to the amenity of a site designated due to its

geological attributes such as an SSSI. Minor sterilisation of a

mineral resource from identified mineral safeguarding area. Minor

physical damage to Local Geological Sites.

Neutral No change to geological receptors identified during the baseline

as a result of the Project.

Minor beneficial

Slight improvement to a site designated due to its geological

attributes such as an improvement in access. An improvement of

access to a mineral safeguarding area (potentially facilitating

future mineral extraction) or a minor improvement in access to a

Local Geological site.

Moderate

beneficial

A moderate improvement to a site designated due to its geological

attributes such as an improvement in access. A moderate

improvement in access to Local Geological Sites as an education

resource and a moderate improvement in access to mineral

safeguarding areas (potentially facilitation future mineral

extraction).

Major beneficial

A major improvement to a site designated due to its geological

attributes such as SSSI; including improvements in access or

physical improvements to the site layout/surrounding

infrastructure. An improvement in access to identified mineral

safeguarding areas (potentially facilitating mineral extraction).

11.4.18 Table 11.6 presents an explanation of the significance criteria utilised in

terms of physical effects of the Project on soils and geology.

Table 11.6 Significance Criteria: Physical Effects of the Project (b)


Major adverse

An increase in the risk of ground stability/soil compaction/erosion

issues from the existing baseline conditions from land which is

structurally stable in the baseline becomes a high or very high

risk. Land that is structurally stable in the existing baseline

becomes capable of landslide, building structural collapse, severe

erosion or severe compaction.

Moderate

adverse

An increase in the risk of ground stability/soil compaction/erosion

issues from the existing baseline becomes a moderate or high

risk. Land that is currently stable / competent in the existing

baseline becomes capable of building subsidence, moderate

erosion or moderate compaction.





Minor adverse

An increase in ground stability risks from the existing baseline

conditions; land that has a low structural stability risk in the

baseline becomes moderate/low risk.

Neutral No change in land topography, soil compaction, soil erosion,

ground stability.

Minor beneficial

A minor improvement to the physical condition of the Project from

the existing baseline conditions, for example land that has a

moderate/low landslide risk in the baseline becomes a low risk.

Moderate

beneficial

A moderate improvement to the physical conditions of the Project

from the existing baseline conditions; for example land that

previously was unused as a result of its physical condition at

baseline is improved such that it comes back into use. For

example earthworks undertaken on railway embankments to

facilitate construction.

Major beneficial

An improvement to the physical condition of the Project from the

existing baseline conditions; for example land that has a very high

risk of landslide or significant erosion in the baseline becomes a

low or very low risk; such that the land is brought back into use.

11.4.19 Table 11.7 presents an explanation of the significance criteria utilised in

terms of ground contamination for the Project.

Table 11.7 Significance Criteria: Land Contamination Risk and Part 2A Status (c)


Major adverse

An increase in contamination risk from the existing baseline

conditions from land that has a very low contamination risk in the

baseline becomes a high or very high risk. Land that does not

meet the statutory definition of Contaminated Land in the existing

baseline becomes capable of being determined under Part 2A.

Moderate

adverse


conditions of land which has a low contamination risk in the

baseline becomes a moderate or high risk. Land that does not

meet the statutory definition of Contaminated Land in the existing

baseline becomes capable of being determined under Part 2A.

Minor adverse


conditions; land that has a low contamination risk in the baseline

becomes moderate/low risk.

Neutral No change in contaminated land risks.

Minor beneficial

A reduction in contamination risk from the existing baseline

conditions, for example land that has a moderate/low

contamination risk in the baseline becomes a low risk.





Moderate

beneficial


conditions; for example land that previously met the statutory

definition of Contaminated Land in the baseline is no longer

capable of being determined as Contaminated Land under Part

2A.

Major beneficial


conditions; for example land that has a very high contamination

risk in the baseline becomes a low or very low risk. Land that

previously met the statutory definition of Contaminated Land in the

baseline is no longer capable of being determined as

Contaminated Land under Part 2A.

11.4.20 Table 11.8 presents the significance criteria utilised during the waste soils

and materials re-use assessment.

Table 11.8 Significance criteria: waste soils and material re-use (e)


Major adverse The generation of significant volumes of hazardous waste

requiring off-site disposal to appropriate landfill.

Moderate

adverse

The generation of a moderate volume of waste requiring offsite

disposal.

Minor adverse The generation of a minor amount of waste.

Neutral No waste generation as part of the Project, materials used

sustainably.

Minor beneficial A minor amount of materials reuse as part of the Project limiting

the offsite disposal of waste.

Moderate

beneficial

A moderate amount of materials reuse as part of the Project

limiting the offsite disposal of waste.

Major beneficial Sustainable use of material including recycling/reusing on site

material. No offsite disposal of wastes to landfill.

11.4.21 An effect that is moderate or major is considered to be a significant effect

in EIA terms for the purposes of this Draft ES. Minor and neutral effects

are not considered to be significant, in accordance with standard EIA

practice.




11.5 Baseline Conditions

11.5.1 Data was collected to establish the baseline geological, hydrogeological,

hydrological and historical conditions through desk study review. The

following sections summarise the key environmental baseline conditions

for the Project, presented from west to east (and south to north for the

Aylesbury branch); additional information is given in the following figures:

Figures 11.1 to 11.8 – Superficial Geology

Figure 11.9 to 11.16 – Solid Geology

Figures 11.17 to 11.24 – Superficial Aquifer Designation

Figures 11.25 to 11.32 – Bedrock Aquifer Classification

Figures 11.73 to 11.80 – BGS Recorded Groundwater Wells

Figures 11.49 to 11.56 – BGS Recorded Mineral Sites

Figures 11.41 to 11.48 – Active Landfills

Figures 11.33 to 11.40 – Historic Landfills

Figures 13.1-13.8 - Water Constraints Maps

11.5.2 It is anticipated that Made Ground will be present along the length of the

Project, primarily associated with the original construction (and in places

removal) of the existing railway, as well as at specific locations where

landfilling or other earthworks have occurred. BGS geological mapping310

indicates that superficial deposits are likely to be present under discrete

sections of the railway, most notably along the eastern end and

associated with surface water courses. Localised superficial deposits

predominantly comprising till and alluvium are anticipated, as well as

windblown (Head) deposits of clay, silt, sand and gravel.

11.5.3 BGS mapping shows the Project to be underlain by the Oxford Clay

Formation, consisting of mudstones from the West Walton Formation,

Weymouth Member, Stewartby Member, and the Peterborough Member.

The Kellaways Formation is also anticipated. No structural features such

as fault lines are indicated to cross the Project Area. More detailed

geological information is provided in the Scoping Report (a copy of this

310 BGS website http://mapapps2.bgs.ac.uk/geoindex/home.html. Accessed September 2016.

http://mapapps2.bgs.ac.uk/geoindex/home.html




can be found in Appendix 1.1); site-specific information obtained from the

ground investigation is summarised below.

11.5.4 Where present, the superficial deposits are classified by the Environment

Agency as being either Secondary A or Secondary (undifferentiated)

aquifers. The mudstones of the Oxford Clay Formation are not water-

bearing strata and are therefore not classified as an aquifer. Where

present, the Kellaways Sand Member is classified, by the BGS mapping,

as a Secondary A aquifer.

11.5.5 The following tables summarise superficial deposits and bedrock

encountered during the intrusive ground investigation, as well as aquifer

classification (where applicable). It should be noted that the geographical

descriptors in this section do not currently correspond with the reporting

sub-sections used in the rest of this Draft ES. The final ES will address

this.

Table 11.9 Summary of Encountered Ground Conditions: Claydon Junction to

Jarvis Lane, Bicester

Superficial/Bedrock

Stratum and General Description

Maximum Reported Thickness

Aquifer Classification

Topsoil – Broadly

cohesive with sand

and gravel

components.

<0.50 m --

Made Ground – Re-

worked deposits of

cohesive and granular

material with varying

clay, sand and gravel

components.

Up to 5 m in railway

footprint of high

embankment,

generally 0.5-2 m

--

Superficial

Alluvium – Silt, Sand

and Gravel. Local

environment

previously dominated

by rivers.

4 m Secondary A

Glacial Deposits –

Cohesive. Soft to firm

bluish grey silty clays

with up to cobble

sized fragments of

chalk and rare bands

of sand.

2 m Secondary

(undifferentiated)




Superficial/Bedrock


Maximum Reported Thickness


Bedrock

Oxford Clay –

Weymouth Member –

Firm becoming very

stiff pale grey

calcareous

mudstone/clay.

20 m Unproductive Strata

Oxford Clay –

Stewartby Member –

Firm becoming very

stiff pale to medium

grey smooth silicate

mudstone/clay with

subordinate beds of

shell debris.

20 m

Oxford Clay –

Peterborough Member

– Firm to very stiff

organic-rich brownish-

grey silicate

mudstone/clay.

25 m

Kellaways Sand

Member – Grey,

calcareous very silty

fine sand / sandy silt.

2 m to 5 m Secondary A

Kellaways Clay

Member – Firm to stiff

grey clay.

1 m to 4 m Unproductive Strata

Cornbrash Limestone

- Limestone, medium-

to fine-grained,

predominantly

bioclastic wackestone;

characteristically

bioturbated and poorly

bedded. Bluish grey

when fresh, but

weathers to olive or

yellowish brown. Thin

argillaceous partings

or interbeds of

calcareous mudstone

may occur.

1 m to 4 m Principal

Forest Marble –

Sillicate- mudstone,

greenish grey,

variably calcareous.

2 m to 7 m Secondary A





Bletchley

Superficial/Bedrock


Maximum Thickness


Topsoil – Broadly cohesive with

sand and gravel components.

<0.5 m --

Made Ground – Re-worked

deposits of cohesive and granular

material with varying clay, sand

and gravel components.

Up to 8 m in

railway footprint

in areas of high

embankment.

Generally

between 0.5

and 2 m.

--

Relic Topsoil – Soft grey to black

organic clay. Organic material is

black amorphous peat.

<0.5 m --

Superficial

Alluvium – Silt, Sand and Gravel.

Local environment previously

dominated by rivers.

2 m Secondary A

River Terrace – Slightly sandy

medium to coarse gravel

deposits.

5 m

Head – Firm sandy gravelly

(stony) clays.

3 m Secondary

(undifferentiated)

Glacial Till – Firm becoming very

stiff sandy gravelly clay with

chalk, flint and mudstone gravel

and occasional cobbles.

30 m Unproductive

Strata

Glacial Deposits

(cohesive/granular) –

Undifferentiated Glacial Deposits

Broadly comprising interbedded

soft to firm occasionally silty,

sandy gravelly clay with

lenses/beds of sand and fine

gravel.

10 m Secondary

(undifferentiated)

Glaciofluvial Deposits – Generally

comprising sand and gravel

deposits of variable thickness

were also encountered.

10 m Secondary A

Bedrock

West Walton Formation – Firm

becoming very stiff dark grey silty

clay with interbedded pale grey

mudstone.

10-15 m Unproductive

Strata

Oxford Clay – Weymouth

Member – Firm becoming very

stiff pale grey calcareous

mudstone/clay.

15-20 m

Oxford Clay – Stewartby Member 20 m




Superficial/Bedrock


Maximum Thickness


– Firm becoming very stiff pale to

medium grey smooth silicate

mudstone/clay with subordinate

beds of shell debris.

Oxford Clay – Peterborough

Member – Firm to very stiff is an

organic rich brownish – grey

silicate mudstone/clay,

25 m


Aylesbury

Superficial/ Bedrock


Maximum Thickness


Topsoil – Broadly cohesive with

sand and gravel components.

<0.5 m --

Made ground – Re-worked

deposits of natural cohesive and

granular material with varying

clay, sand and gravel

components. Material also

contains varying quantities of

ballast, clinker and ash.

Up to 8 m in

areas of high

embankment.

Generally 0.5 –

2 m

--

Relic topsoil – Stiff dark brown

silty clay with black silty organic

partings.

--

Superficial

Alluvium – Silt, sand and gravel.

Local environment previously

dominated by rivers - soft to firm

light brown mottled grey clay with

orange/brown silt partings.

2 m Secondary A

River Terrace Deposits – Multi-

coloured clayey fine to coarse

sand and gravel.

2 m

Head Deposits – Firm grey

mottled orange slightly sandy

clay.

2 m Secondary

(undifferentiated)

Glacial Deposits – These

deposits are highly localised on

the Sub-section 2E route.

2 m

Bedrock

Kimmeridge Clay – Firm to very

stiff sandy silty clay.

35-40 m Unproductive

Strata

Ampthill Clay: Firm becoming

very stiff smooth or slightly silty

pale to medium grey firm to stiff

clay.

10-20 m




Superficial/ Bedrock


Maximum Thickness


West Walton Formation: Firm

becoming very stiff dark grey silty

clay interbedded pale grey

mudstone.

10-15 m

Oxford Clay – Weymouth

Member: Firm becoming very stiff

pale grey calcareous

mudstone/clay.

15-20 m

Oxford Clay – Stewartby Member:

Firm becoming very stiff pale to

medium grey smooth silicate

mudstone/clay with subordinate

beds of shell debris.

20 m

Oxford Clay – Peterborough

Member: Firm to very stiff: an

organic rich brownish grey silicate

mudstone/clay.

25 m

Kellaways Formation – Grey

calcareous very silty fine sand/

sandy silt (Kellaways Sand

Member) overlying a firm to stiff

grey clay (Kellaways Clay

Member).

Unknown Secondary A

11.5.6 The following table provides details of mineral safeguarding areas which

could potentially be affected by mobilisation of contamination during

construction/operation of the Project.

Table 11.12 Summary of Potential Mineral Resources from Mineral Safeguarding

Plans

Sub-section Mineral Safeguarding Areas and Geologically Designated Sites

Cherwell District

Council sub-

section

Superficial deposits – Sub-alluvial: Inferred resources a band of

alluvium crossing the Project Area to the east of Bicester.

Aylesbury Vale:

Claydon/Quainton

sub-section

Bedrock deposits – Brick Clay underlying much the East West

portion of the former Varsity line route from Marsh Gibbon to

Verney Junction


alluvium crossing the Project Area to the east of Verney Junction.

River terrace deposits adjacent to the eastern extent of the Sub-

section.

Aylesbury Vale:

Claydon/Quainton

sub-section




Sub-section Mineral Safeguarding Areas and Geologically Designated Sites

Aylesbury Vale:

Winslow /

Swanbourne sub-

section

Superficial deposits – Glaciofluvial sand and gravel deposits

intersect with the Project in multiple areas surrounding Winslow.


alluvium crossing the Project Area to the north of Winslow.

Aylesbury Vale:

Aylesbury sub-

section


alluvium crossing the Project Area to the north of Waddesdon and

Fleet Marston Farm.

Superficial deposits – River terrace deposits underlie the Project

Area within Aylesbury to the north west of Quarrendon

Wycombe District

Council sub-

section


alluvium adjacent to the Project Area at the northern extent of the

Sub-section.

River terrace deposits a narrow band adjacent to the northern

boundary of the Sub-section.

Milton Keynes

Council sub-

section

River terrace deposits a narrow band to the north of Bletchley

Brickworks (Newton Longville).

As the route branches to the north of Bletchley station it becomes

underlain by Bedrock deposits of Brick Clay with multiple historic

brickworks identified surrounding Milton Keynes.

As the route extends to the east of Bletchley it is underlain by River

terrace deposits and Brick Clay deposits surrounding Fenny

Stratford. Further to the east the former Station Brick and Tile

works and the Woburn sands Brickworks historic clay extraction

sites have been identified.

Central

Bedfordshire

Council sub-

section

Bedrock deposits - Outcrop area of Lower Oxford Clay surrounding

historic clay pits adjacent to Quest clay pit.

Bedrock deposits – Woburn Sands intersect with the Project Area

to the north of Aspley Guise.

Bedford Borough

Council sub-

section

Bedrock deposits - Outcrop area of Lower Oxford Clay surrounding

historic clay pits adjacent to Kempston Hardwick further to the

north of Elstow the route is underlain by River gravel resources.

11.5.7 No Local Geology Sites or RIGs have been identified within 500 m of the

Project Area Boundary.

Ground Stability and Soil Compaction

11.5.8 Geological hazard information has been collated and is summarised in the

following table:




Table 11.13 Summary of Geological Hazards by Project Sub-section

Geological Hazards Predominant classification

Exceptions and sub-section impacted

Collapsible Ground No hazard to very low hazard --

Compressible

Ground Predominantly no hazard

Alluvial deposits designated as

moderate hazard in Cherwell

District Council, Aylesbury

Vale: Winslow/Swanbourne,

Aylesbury Vale: Aylesbury,

Wycombe District Council,

Milton Keynes Council ,

Central Bedfordshire Council ,

Bedford Borough Council sub-

sections

Dissolution No hazard to low hazard --

Landslide Predominantly very low hazard

A band in the Aylesbury Vale:

Claydon/Quainton sub-section

designated moderate hazard

Running

Sand

Predominantly no hazard in

Cherwell District Council,

Aylesbury Vale:

Claydon/Quainton, Aylesbury

Vale: Aylesbury and Wycombe

District Council sub-sections.

Predominantly very low hazard

in Aylesbury Vale:

Winslow/Swanbourne, Milton

Keynes Council, Central

Bedfordshire Council and

Bedford Borough Council sub-

sections.

Variable - with multiple areas

of alluvium designated low

hazard and areas of river

terrace deposits and glacial till

designated very low hazard

across all sub-sections

Shrinking or Swelling

Clay

Predominantly designated

moderate hazard associated

with Oxford Clay within

Cherwell District Council,

Aylesbury Vale:

Winslow/Swanbourne,

Aylesbury Vale:

Claydon/Quainton sub-

sections becoming low to the

north west of Aylesbury within

Aylesbury Vale: Aylesbury

sub-section

Project within Wycombe

District Council sub-section

predominantly designated no

hazard with bands designated

very low hazard and moderate

hazard in the north of

Wycombe District Council sub-

section

Radon Hazards

The majority of the route is

designated as a lower

probability radon area, with

less than 1 % of homes

exceeding the action level.

There are however areas of

intermediate designation in the

Aylesbury, Wycombe District

Council and Milton Keynes

Council sub-sections.




Geological Hazards Predominant classification

Exceptions and sub-section impacted

Mining Hazards

According to Coal Authority

records, no part of the entire

Project Area including all sub-

sections lies within a zone of

likely physical influence at the

surface from any past or

present underground workings.

--

Hydrology

11.5.9 Numerous watercourses intersect with the Project Area within each of the

sub-sections. These watercourses include the following Environment

Agency designated main rivers, ordinary rivers and surface water features

such as lakes.




Table 11.14 Summary of Controlled Waters Receptors by Sub-section

Sub-section

Controlled water receptors including Environment Agency main rivers intersecting with Study Area

Discharge to Aquifer classification(s)

Cherwell

District

Council

sub-section

Langford Brook and Launton Brook both

Main Rivers

Langford Brook discharges to the River

Ray, Launton Brook discharges to

Cutters Brook

Superficial : Predominantly not classified

aside from Alluvium classified as Secondary

A Aquifer

Bedrock: Predominantly Unproductive Strata

Limited extent underlain by Secondary A

Aquifer

Aylesbury

Vale:

Claydon /

Quainton

sub-section

East West Alignment

Beaconhill Ditch Main River, Fleet Marston

Brook Main River

Grebe Lake

Calvert Jubilee Local Nature Reserve

Four tributaries of Padbury Brook

Claydon Brook

North South Alignment

Muxwell Brook Main River

Two ordinary watercourses

Greatmoor Ditch

The River Ray Main River

Doddershall Brook Main River

Beaconhill Ditch discharges to Cutters

Brook

Claydon Brook discharges to Padbury

Brook

The two ordinary watercourses

discharge to Muxwell Brook and the

River Ray

Greatmoor Ditch discharges to the River

Ray

Doddershall Brook confluences with

Tetchwick Brook

Superficial : Predominantly not classified

aside from Alluvium and River Terrace

Deposits classified as Secondary A Aquifers

Diamicton classified as Unproductive Strata

Bedrock: predominantly Unproductive Strata




Sub-section



Aylesbury

Vale:

Winslow /

Swanbourne

sub-section

None --

Superficial: Predominantly classified as

Unproductive Strata aside from Alluvium and

Glaciofluvial Deposits classified as

Secondary A Aquifer. Limited bands

designated as Secondary (undifferentiated)

Aquifers

Bedrock: Unproductive Strata

Aylesbury

Vale:

Aylesbury

sub-section

Fleet Marston Brook Main River

River Thame (mapping indicates this river

has been subject to historic diversion) Main

River

Bear Brook Main River

Coldharbour Way Ditch Main River

California Brook Main River

Southcourt Brook

Stoke Brook Main River

Fleet Marston Brook discharges to the

River Thame

Bear Brook discharges to the River

Thame

California Brook discharges to Bear

Brook

Southcourt Brook confluences with Bear

Brook

Stoke Brook confluences with Bear

Brook

Superficial: Alluvium and River Terrace

Deposits classified as Secondary A Aquifer.

Limited bands designated as Secondary

(undifferentiated) Aquifers


with bands of Secondary A and Secondary

(undifferentiated) Aquifers. A Principal

Aquifer is mapped within Aylesbury (though

outside the Project)

Wycombe

District

Council

sub-section

The Terrick Brook Main River

Scotsgrove Brook ordinary watercourse

Three ordinary watercourses

Scotsgrove Brook confluences with

Terrick Brook

The three ordinary watercourses

confluence with Horsenden Stream

Superficial: Alluvium and River Terrace

Deposits classified as Secondary A Aquifers.

Limited bands designated as Secondary

(undifferentiated) Aquifers

Bedrock: Unproductive Strata with the Chalk

in the south of the Sub-section identified as a

Principal Aquifer.




Sub-section



Milton

Keynes

Council

sub-section

The River Ouse Main River

Unnamed ordinary watercourse 80 m to the

south of the Project

Loughton Brook ordinary watercourse

Unnamed tributary of Loughton Brook

ordinary watercourse

The Grand Union Canal

The River Ouzel Main River

The River Great Ouse Main River

Caldecotte Lake

Five minor watercourses to the east of Fenny

Station

The unnamed watercourse discharges

to Water Easton Brook and River Ouzel

The five minor watercourses to the east

of Fenny Station discharge to the River

Ouzel

Superficial: Alluvium, Stoke Goldington

Member, Felmersham Member and River

Terrace Deposits classified as Secondary A

Aquifers. Limited bands of Head Deposits


Aquifers.

Oadby Member designated Unproductive

Strata


with bands of Secondary A Aquifers

associated with the Kellaways Formation

Central

Bedfordshir

e Council

sub-section

None --

Superficial: Alluvium and Stoke Goldington

Member classified as Secondary A Aquifers.

Head Deposits designated as Secondary

(undifferentiated) Aquifers.

Oadby Member designated Unproductive

Strata

Bedrock: Unproductive Strata




Sub-section



Bedford

Borough

Council

sub-section

Elstow Brook

The River Great Ouse

Minor ordinary watercourses

The majority of minor ordinary

watercourses discharge to Elstow Brook

Superficial: Alluvium, Stoke Goldington

Member and Felmersham Member classified

as Secondary A Aquifers. Head Deposits


Aquifers.


with Secondary A Aquifers associated with

the Kellaways Sand Member.

A Principal Aquifer of the Greater Oolite

Group within Bedford.




11.5.10 For the purposes of the assessment these surface water features will be

considered sensitive water quality receptors. The locations of these are

shown on Figures 13.1-13.8 (Water Constraints Map).

11.5.11 The following sensitive ecological receptors have been identified within 1

km of the Project Boundary:

Table 11.15 Summary of Designated Ecological Sites by Sub-section

Sub-section Off-site sensitive ecological receptors

Cherwell District

Council Upper Thames Tributaries

Aylesbury Vale:

Claydon/Quainton Sites of Special Scientific Interest (SSSI): Sheephouse Wood and

Finemere Wood

Wycombe District

Council

Special Area of Conservation (SAC): The Chilterns

Two SSSIs: Ellesborough and Kimble Warrens

Milton Keynes

Council Local Nature Reserve named the Blue Lagoon

11.5.12 On review of the characteristics of each of these sites and their proximity

to the Project, the potential for soils/geology-related impact upon these

receptors is not considered likely to be significant. No further

consideration of ecological receptors is made in this chapter; full

assessment and details are given in Chapter 9 (Ecology).

Potential for Re-use of Soils and Waste Soils

11.5.13 The efficient use of resources is stipulated in legislation, policy and best

practice guidance. Network Rail’s Sustainable Procurement Policy311

states that in terms of waste, the aim is for “zero waste to landfill and

increased use of sustainable and recycled materials”.

11.5.14 A combined Site Waste Management Plan (SWMP) and Materials

Management Plan (MMP) tool has been created for the Project to forecast

and confirm the ultimate destination of excess/unsuitable soil arisings

311 Network Rail, Sustainable Development Strategy (2013-2024), Version 0.71,

http://www.networkrail.co.uk/browse%20documents/strategicbusinessplan/cp5/supporting%20documents/transforming%20network%20rail/sustainable%20development%20strategy.pdf [Online, 13 November 2015]




generated during construction of the Project. All materials which are to be

sent to landfill will be accompanied by a justification.

11.5.15 Information on the nature of the soils within the Project will be collected

during detailed design to undertake a detailed assessment of the

suitability of existing materials for re-use and the appropriate destination

for waste soils. In the meantime, the general principle that will be adhered

to is that the material must be suitable for its proposed use or offsite

disposal destination, both geotechnically and in terms of contamination.

The stockpiling of potentially contaminated ballast, for example adjacent

to a watercourse, would be considered a risk to a sensitive receptor (the

surface water), and would therefore not be carried out.

11.5.16 Another risk for consideration is the potential for some of the existing

railway ballast/fill material to be contaminated. Frequently railway land can

be impacted by asbestos, metals, metalloids and their compounds and

ash, arising from historic construction. In addition, historic operation of the

railway can also lead to contamination. This contamination is most likely

to occur in areas where trains have been stationary (sidings and stations).

This contamination could result in the material being classified as

hazardous waste following earthworks. Network Rail follow a procedure

for handling used ballast (NR/L3/ENV/044) that requires the waste to be

correctly categorised and handled. The standard is to guard against

pollution and to fulfil statutory requirements, such as the duty of care to

the handling, transport and management of waste, and has been agreed

with the Environment Agency

Ground Contamination

11.5.17 For the Project, key potential contamination sources are considered to be:

Contamination associated with the existing railway, as works proposed require modernisation of existing railway much of which predates the earliest available historical maps (c1880s);

Areas of historic clay extraction and brick manufacturing have been identified surrounding Calvert, Stewartby, Kempston Hardwick and Bletchley. Some of these former brick fields have subsequently been put to use as landfills, both historically and up to the present day; and




Historical potentially contaminative industries such as gas works sites and sewage farms adjacent to the Project where it passes urban areas such as Bicester, Aylesbury and Bletchley.

11.5.18 Ground conditions data from the initial round of intrusive

investigation312,313,314,315 found:

No exceedances of the applied generic assessment criteria were recorded as part of the soils testing undertaken;

No soil leachabilty or groundwater analytical testing was undertaken; and

Asbestos was not detected by the analytical laboratory in any of the soil samples recovered during any phases of investigation.

Environmental Receptors

11.5.19 The following sensitive receptors have been identified as relevant to the

assessment of contamination in respect of the Project.

Human Receptors

11.5.20 Public access to the parts of the Project Area where exposure is likely to

occur (such as earthworks during construction or operational railway

infrastructure during operation) during construction and operation will be

limited. The Project will provide fencing to prevent unauthorised access or

trespassing to these parts of the Project Area during construction and

operation. The only human health receptors with direct access to the soils

underlying the Project are considered to be construction and maintenance

workers, potentially undertaking excavation. Exposure is unlikely to occur

in the parts of the Project Area that members of the public (e.g. footpath

users, farmers, station users, road users) will have access to during

construction or operation.

312 WSP | Parsons Brinckerhoff, (2015). East West Rail - Phase 2, Ground Investigation Report, Phase 2A, Claydon Junction

to Jarvis Lane. Bicester.

313 WSP | Parsons Brinckerhoff, (2015). East West Rail - Phase 2, Ground Investigation Report, Phase 2B, Part Single Bi-

Directional Freight & Part Disused Line.

314 WSP | Parsons Brinckerhoff, (2015). East West Rail - Phase 2, Ground Investigation Report, Phase 2E, Aylesbury Central

to Calvert Junction.

315 WSP | Parsons Brinckerhoff, (2015). East West Rail - Phase 2, Ground Investigation Report, Phase 2F, Aylesbury to

Princes Risborough.




11.5.21 Off-site human health receptors including residential housing in both

estates and individual properties have been identified adjacent to the

Project Area at the following locations:

Table 11.16 Off-Site Human Health Receptors

Sub-section Off-Site Residential Areas

Cherwell District

Council Bicester, Launton

Aylesbury Vale:

Claydon /

Quainton Charndon, Twyford, Steeple Claydon, Verney Junction

Aylesbury Vale:

Winslow /

Swanbourne Winslow, Newton Longville

Aylesbury Vale:

Aylesbury Waddeson, Aylesbury

Wycombe

District Council Marsh

Milton Keynes

Council Bletchley, Woburn Sands

Central

Bedfordshire

Council

Woburn Sands, Aspley Guise, Husborne Crawley, Brogborough,

Lidlington

Bedford

Borough Council Stewartby, Kempston

11.5.22 The following human health receptors have therefore been considered:

On-site:

o Construction workers; and

o Future maintenance workers.

Off-site:

o Residents in adjacent properties during construction and operation; and

o Recreational users of adjacent land, e.g. footpaths, during construction and operation.

11.5.23 The principal contaminant exposure pathways to on-site (within the

Project Area) human receptors are:




Dermal contact with, inhalation of and / or ingestion of contaminants in soil and water; and

Inhalation of ground gases or asbestos fibres.

11.5.24 The principal contaminant exposure pathways to off-site (beyond the

Project Boundary but within 500 m of it ) human receptors are:

Dermal contact with and / or ingestion of contaminants in windblown soil-derived dusts and water which may have migrated off-site;

Inhalation of contaminants in windblown dust; and

Inhalation of vapours or asbestos fibres which may have migrated off-site.

Controlled Water Receptors

11.5.25 The following potential controlled water receptors have been identified:

Main Rivers which cross the line of the railway – Launton Brook, Langford Brook, Beaconhill Ditch, Fleet Marston Brook, Muxwell Brook, the River Ray, Doddershall Brook, Fleet Marston Brook, the River Thame, Bear Brook, Coldharbour Way Ditch, Southcourt Brook, Stoke Brook, the Terrick Brook, the River Ouse, the River Ouzel, the River Great Ouse, Elstow Brook;

Ordinary water courses which cross the line of the railway – Scotsgrove Brook, Loughton Brook, multiple unnamed tributaries;

Surface water bodies adjacent to the Project – Grebe Lake, the Grand Union Canal and several smaller ponds identified during ecology surveys (further information can be found in Chapter 9 (Ecology));and

Sensitive superficial and bedrock aquifers underlying the Project.

11.5.26 Principal contaminant migration pathways for controlled waters receptors

comprise:

Surface runoff;

Infiltration and lateral migration; and

Infiltration and vertical migration.

Property Receptors

11.5.27 Property receptors located within the Project Area may have the potential

to be affected by contamination during both the construction and

operational phases of the Project. The following on-site property

receptors have been identified:




Station buildings including below ground utility services – Winslow Station; and

Railway platforms – Aylesbury Vale Parkway, Woburn Sands, Ridgmont, and Princes Risborough stations.

11.5.28 The following off-site property receptors have been identified:

Buildings including residential homes and commercial properties within 500 m of the Project Boundary.

11.5.29 Potential pathways comprise:

Direct contact with aggressive ground conditions; and

Migration through permeable ground/via utility corridors/cracks in floor slab/service entry points – accumulation of gases and vapours in confined spaces generating potentially explosive atmosphere.

Preliminary Conceptual Site Model

11.5.30 A Conceptual Site Model (CSM) identifies the potential or known sources

of contamination, receptors and migration or exposure pathways. Where

all three are present or considered likely to be present, i.e. source –

pathway – receptor, this is termed a Potential Contaminant Linkage

(PCL). Three preliminary CSMs (baseline, construction and operation)

were developed for the Project using the baseline information summarised

above. The baseline Conceptual Site Models (CSM) for ground

contamination, subdivided by reporting sub-section, are presented in the

following section. All potential contaminant linkages identified have been

displayed within the relevant baseline CSM tables. Pathways relevant to

human health receptors including the risk of direct ingestion of soils, direct

contact with groundwater, and inhalation of vapours have largely been

assessed as low risk. Pathways relevant to controlled waters receptors

such as infiltration and leaching have also been assessed as Low

depending on the underlying geology of the Project in the sub-section.

11.5.31 A summary of the PCLs is given in the following sections and in Table

11.17 to Table 11.24.




Table 11.17 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Cherwell District Council sub-section

Source of risk Pathway / action Receptor Consequence Probability Risk

Existing

contamination within

Made Ground of

unknown provenance

associated with the

historical uses of the

land surrounding the

Project Area.

Dermal contact/ ingestion/

inhalation of contaminated dust

or soil.

Inhalation of windblown dust,

fibres or vapours.

Off-site residents of adjacent

properties. Medium Low likelihood

Moderate / low

risk

Recreational users of adjacent

land Medium Low likelihood

Moderate / low

risk

Maintenance workers on existing

line Minor Low likelihood Very low risk

Surface run-off

Migration of contaminants

through granular or fractured

materials

Leaching / migration of

contaminants through Made

Ground and along preferential

pathways

Superficial Secondary A aquifer

(Alluvial deposits)

Launton Brook, Langford Brook

Minor Low likelihood Very low risk

Geological hazards

(ground stability)

Collapsible ground Existing on- and off-site structures Medium Unlikely Low risk

Compressible ground Existing on- and off-site structures Medium Low likelihood Moderate / low

risk

Ground dissolution Existing on- and off-site structures Medium Unlikely Low risk

Landslide Existing on- and off-site structures Medium Unlikely Low risk

Geological hazards (ground stability)

Running sand Existing on- and off-site structures Medium Unlikely Low risk

Shrinking / swelling clay Existing on- and off-site structures Medium Unlikely Low risk




Table 11.18 Baseline Phase Conceptual Site Model Findings: Potential Contaminant Linkages within the Aylesbury Vale: Claydon/Quainton sub-section


Existing


Made Ground of

unknown provenance

associated with the



Project Area.



and soil.


fibres or vapours.


properties.

Medium Low likelihood Moderate/ Low

risk


land

Medium Low likelihood Moderate/ Low

risk


line


Surface run-off



materials




pathways

East-West Alignment:

Beaconhill Ditch Main River, Fleet Marston Brook Main River

Grebe Lake

Calvert Jubilee Local Nature Reserve

Four tributaries of Padbury Brook

Claydon Brook

North-South Alignment:

Muxwell Brook Main River

Two ordinary watercourses

Greatmoor Ditch

The River Ray Main River

Doddershall Brook Main River Beaconhill Ditch, Little Marsh Ditch, Tetchwick Brook and Fleet Marston Brook.







(Alluvium & River Terrace

Deposits)


Infill material

associated with the

former Calvert clay

pits/brick works

Migration of ground gas through

permeable ground/ utility

corridors/ cracks in floor slabs/

service entry points with

potential accumulation to

explosive atmospheres

Built environment receptors:

Buildings and, subsurface

structures including utilities

surrounding the Project Area.

Mild Low likelihood Low risk

Off-site human health receptors in

properties adjacent to the Project

Severe Low likelihood Moderate risk

Migration of landfill leachate into

the Project Area

Subsurface

infrastructure/foundations


Geological hazards

(ground stability)


Compressible ground Existing on- and off-site structures Medium Unlikely Low risk


Landslide Existing on- and off-site structures Medium Low likelihood Moderate / low

risk


Shrinking / swelling clay Existing on- and off-site structures Medium Low likelihood Moderate / low

risk




Table 11.19 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Aylesbury Vale: Winslow/Swanbourne sub-section.


Existing


Made Ground of

unknown provenance

associated with the



Project Area.



and soil.


fibres or vapours.


properties.



land



line


Surface run-off

Migration of contaminants through

granular or fractured materials




pathways

Horwood Brook

Unnamed minor watercourse to

the east of Whaddon Road.


Superficial Secondary A aquifer Minor Low likelihood Very low risk

Buried waste of

unknown provenance

at the active landfill at

Newton Longville

Project and the

surrounding historic

landfills.




service entry points with potential

accumulation to explosive

atmospheres


Buildings, subsurface structures

including utilities surrounding the

Project Area.






the Project Area

Subsurface infrastructure /

foundations






Geological hazards

(ground stability)


Geological hazards

(ground stability)

Compressible ground Existing on- and off-site structures Medium Low Moderate / low

risk




Shrinking / swelling clay Existing on- and off-site structures Medium Low Moderate / low

risk




Table 11.20 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Aylesbury Vale: Aylesbury sub-section


Existing contaminants

within Made Ground

of unknown

provenance

associated with the



Project Area.



and soil.


fibres or vapours.


properties.


Maintenance workers on

existing line


Surface run-off






pathways e.g. newly-created

service runs.

Fleet Marston Brook

The River Thame

Bear Brook

Coldharbour Way Ditch

California Brook

Stoke Brook



Bedrock Principal & Secondary

A aquifers

Medium Low likelihood Moderate / low

risk

Buried waste of

unknown provenance

adjacent to the Project

Area including

Channel Infill

associated with the

River Thame.






atmospheres




Project Area.


Off-site human health receptors

in properties adjacent to the

Project



the Project Area

Subsurface



Geological hazards Collapsible ground Existing on- and off-site Medium Unlikely Low risk





(ground stability) structures

Geological hazards

(ground stability)

Compressible ground Existing on- and off-site

structures


risk

Ground dissolution Existing on- and off-site

structures

Medium Unlikely Low risk

Landslide Existing on- and off-site

structures


Running sand Existing on- and off-site

structures


Shrinking / swelling clay Existing on- and off-site

structures


risk




Table 11.21 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Wycombe District Council sub-section.



within Made Ground

of unknown

provenance

associated with the



Project Area.



and soil.


fibres or vapours.


properties.



line


Surface run-off



materials





service runs.

Terrick Brook and Scotsgrove

Brook


Superficial Secondary A &

Principal Bedrock aquifers


risk

Buried waste of

unknown provenance


Area associated with

historic landfilling.










Project Area.






the Project Area

Subsurface infrastructure/

foundations


Geological hazards Collapsible ground Existing on- and off-site structures Medium Unlikely Low risk





(ground stability)

Geological hazards

(ground stability)


risk








Table 11.22 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Milton Keynes Council sub-section



within Made Ground

of unknown

provenance

associated with the



Project Area.



and soil.


fibres or vapours.


properties.



line


Surface run-off



materials





service runs.

The River Great Ouse, the Blue

Lagoon LNR, Caldecotte Lake

and the Grand Union Canal


Superficial & Bedrock Secondary

A aquifers


risk

Buried waste of

unknown provenance


Newton Longville site

and the surrounding

historic landfills.










Project Area.






the Project Area

Subsurface infrastructure/

foundations


Geological hazards

(ground stability)







risk


Geological hazards

(ground stability)







Table 11.23 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Central Bedfordshire Council sub-section.



within Made Ground

of unknown

provenance

associated with the



Project Area.



and soil.


fibres or vapours.

Members of the public within the

vicinity of the Project



line


Surface run-off



materials





service runs.

Controlled waters: The Broughton

Brook (ordinary watercourse)

Tertiary unnamed rivers in the

vicinity.

Natural Ponds


Superficial Secondary A aquifer Mild Low likelihood Low Risk

Buried waste of

unknown provenance

within the


landfills.










Project Area.






the Project Area

Subsurface



Geological hazards Collapsible ground Existing on- and off-site structures Medium Unlikely Low risk





(ground stability)

Geological hazards

(ground stability)


risk








Table 11.24 Baseline Conceptual Site Model Findings: Potential Contaminant Linkages within the Bedford Borough Council sub-section



within Made Ground

of unknown

provenance

associated with the



Project Area.



and soil.


fibres or vapours.


properties.



line


Surface run-off



materials





service runs.

Groundwater (SPZ): Superficial

Secondary A and bedrock

Principal aquifers

Numerous water bodies within the

sub-section which cross the

Project Area.

The River Ouse and an unnamed

river.


risk

Buried waste of

unknown provenance

within and

surrounding the

historic landfills.








Buildings and subsurface

structures including utilities

surrounding the Project Area.






the Project Area

Subsurface



Geological hazards

(ground stability)







risk


Geological hazards

(ground stability)







11.6 Assessment of Effects

Construction

11.6.1 This section considers the assessment of the construction phase of the

Project. The following potential sources of contamination, receptors and

exposure/migration pathways have been identified:

The disturbance of existing contamination associated with historic/current landfilling/other land uses and the introduction of new pathways for migration;

Excavation, storage and removal of potentially contaminated materials;

The introduction of potentially polluting substances through storage of chemicals, solvent and the use of fuels/oils;

The potential for off-site migration of contaminants and increased suspended solid loading in surface water run-off;

The introduction of human health receptors (construction/future maintenance workers); and

The potential for migration of contaminants to groundwater (Project Area underlain by Principal aquifer within Wycombe District Council and Bedford Borough Council sub-sections, with a groundwater SPZ identified within Bedford), taking into account the minor works currently proposed in these sub-sections.

11.6.2 Temporary structures will be established within construction compounds

of varying sizes including welfare facilities, offices and storage buildings.

These structures are assumed to be modular shipping container type units

which are unlikely to possess below ground foundations. These structures

have therefore been excluded as ‘built environment’ receptors. The new

station at Winslow and the identified platform extensions have been

included. Further information on the proposed works during construction

can be found in Chapter 2 (Project Description).

11.6.3 In addition to the mitigation measures set out in Section 11.2 (Limitations

and Assumptions) the following assumptions have been incorporated into

the assessment of the construction phase of works:

Appropriate best practice techniques and guidance such as CLR11 and the Environment Agency guidance on Piling into Contaminated




Sites316 will be adhered to in order to minimise and prevent pollution being introduced or mobilised as a result of the Project;

Appropriate working practices will be adopted such as the use of dust suppression during dry site conditions to limit off-site dust dispersal;

Contamination was not encountered during the various phases of intrusive ground investigation, though it may be present associated with historic land uses in the vicinity of the Project. It has been assumed that during the construction phase, potentially contaminated soils encountered will be appropriately managed.

Where material is removed due to its chemical unsuitability for retention at the site, full records should be maintained and a verification report prepared following Environment Agency guidance;

A combined SWMP and MMP tool will be used for the Project to forecast and confirm the ultimate destination of arisings generated during construction phase of the Project;

There is the potential for groundwater flow to be impacted by deep excavation and the use of piling/drilling during the construction phase. This is particularly likely during the construction of the new station at Winslow, the platform extensions and the construction of new bridges;

Piling risk assessments will be prepared where piling is proposed within a groundwater source protection zone, within 8 m of an Environment Agency main river or close to potential sources of contamination such as landfills or chemical works;

The majority of the Project Area in which excavation/construction is proposed is underlain by unproductive strata and much of the work to be undertaken requires only limited shallow excavation with the construction of near surface structures (tracking/ signalling); and

Aside from the discussed localised areas of construction no changes to the ground surface composition and thus water infiltration rates are anticipated to be required within the Project Area.

11.6.4 There is the potential for off-site contamination in the form of

contaminated soils, leachate and ground gas to impact receptors

(construction/maintenance workers) within the Project Area associated

with historic/contemporary landfilling in the vicinity of the Project and other

historic sources.

11.6.5 The following Tables 11.25 to 11.32 present the CSM findings for the

construction phase.

316 Environment Agency. 2002. Piling into Contaminated Sites.




Table 11.25 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Cherwell District Council sub-section


Existing


Made Ground of

unknown provenance

associated with the



Project Area.

Contaminants

introduced to the

Project, e.g. fuel and

oils for construction

plant and equipment.


inhalation of contaminated

dust and soil.


fibres or vapours.


properties.


land

Mild Likely Moderate / Low risk



dust and soil.


fibres or vapours..

Construction workers Mild Low likelihood Low risk

Contaminants

introduced to the




Increase in

suspended silts into

surface run-off

Surface run-off



materials



Ground and along

preferential pathways e.g.

newly-created service runs.


(Alluvial deposits)

Launton Brook and Langford

Brook

Minor Likely Low risk

Geological hazards Collapsible ground Existing and new, on- and off-site

structures






(ground stability) Compressible ground Existing and new, on- and off-site

structures

Medium Low likelihood Moderate / low risk

Ground dissolution Existing and new, on- and off-site

structures


Landslide Existing and new, on- and off-site

structures


Running sand Existing and new, on- and off-site

structures


Shrinking / swelling clay Existing and new, on- and off-site

structures





Table 11.26 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Claydon/Quainton sub-section


Existing


Made Ground of

unknown provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.


fibres or vapours.


properties.


land




dust and soil.


fibres or vapours.


Contaminants

introduced to the




Increase in suspended

silts into surface run-

off

Surface run-off



materials



Ground and along



Multiple surface water courses as

listed in Table 11.14.

Minor Low likelihood Low risk


(Alluvium & River Terrace

Deposits)






Infill material

associated with the

former Calvert clay

pits/brick works

Migration of ground gas

through permeable ground/

utility corridors/ cracks in

floor slabs/ service entry

points with potential


atmospheres




Project Area.





Construction workers Severe Low likelihood Moderate risk

Migration of landfill leachate

into the Project Area

Subsurface



Geological hazards

(ground stability)

Collapsible ground Existing and new, on- and off-site

structures


Compressible ground Existing and new, on- and off-site

structures



structures



structures



structures



structures





Table 11.27 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Winslow/Swanbourne sub-section


Existing


Made Ground of

unknown provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.


fibres or vapours.


properties.


land

Mild Likely Moderate/ Low risk



dust and soil.


fibres or vapours.


Contaminants

introduced to the






off

Surface run-off



materials



Ground and along




Horwood Brook

An unnamed minor watercourse

to the east of Whaddon Road.






Buried waste of

unknown provenance


Newton Longville

Project and the


landfills.







atmospheres




Project Area.








Subsurface



Geological hazards

(ground stability)


structures



structures

Medium Low Moderate / low risk


structures



structures



structures



structures

Medium Low Moderate / low risk




Table 11.28 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Aylesbury sub-section



within Made Ground

of unknown

provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.


fibres or vapours.


properties.




dust and soil.


fibres or vapours.


Contaminants

introduced to the






off

Surface run-off



materials



Ground and along



Fleet Marston Brook

The River Thame

Bear Brook

Coldharbour Way Ditch,

California Brook

Stoke Brook



Bedrock Principal & Secondary A

aquifers

Medium Likely Moderate risk





Buried waste of

unknown provenance


Area including

Channel Infill

associated with the

River Thame.







atmospheres




Project Area.








Subsurface



Geological hazards

(ground stability)


structures



structures



structures



structures



structures



structures





Table 11.29 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Wycombe District Council sub-section



within Made Ground

of unknown

provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.


fibres or vapours.


properties.

Mild Likely Moderate/ Low risk



dust and soil.


fibres or vapours.


Contaminants

introduced to the






off

Surface run-off



materials



Ground and along




Brook


Superficial Secondary A &

Principal Bedrock aquifers

Medium Low likelihood Moderate risk





Buried waste of

unknown provenance










atmospheres




Project Area.








Subsurface



Geological hazards

(ground stability)


structures



structures



structures



structures



structures



structures





Table 11.30 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Milton Keynes Council sub-section



within Made Ground

of unknown

provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.


fibres or vapours.


properties.




dust and soil.


fibres or vapours.

Construction / Maintenance

workers

Minor Low likelihood Low risk

Contaminants

introduced to the






off

Surface run-off



materials. Leaching /

migration of contaminants

through Made Ground and

along preferential pathways

e.g. newly-created service

runs.


Lagoon LNR, Caldecotte Lake

and the Grand Union Canal


Superficial & Bedrock Secondary

A aquifers






Buried waste of

unknown provenance


Newton Longville site

and the surrounding

historic landfills.







atmospheres




Project Area.









foundations


Geological hazards

(ground stability)


structures



structures



structures



structures



structures



structures





Table 11.31 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Central Bedfordshire Council sub-section



within Made Ground of

unknown provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.


fibres or vapours.


properties.




dust and soil.


fibres or vapours.


Contaminants

introduced to the






off

Surface run-off



materials



Ground and along



Broughton Brook (ordinary

watercourse)


Superficial Secondary A aquifer Mild Likely Moderate / low risk

Buried waste of

unknown provenance

within the surrounding












historic landfills. floor slabs/ service entry



atmospheres

Project Area.







Subsurface



Geological hazards

(ground stability)


structures



structures



structures



structures



structures



structures





Table 11.32 Construction Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Bedford Borough Council sub-section



within Made Ground

of unknown

provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.


fibres or vapours.


properties. Mild Likely Moderate / Low risk



dust and soil.


fibres or vapours.


Contaminants

introduced to the






off

Surface run-off



materials



Ground and along




Secondary A and bedrock

Principal aquifers

Medium Likely Moderate risk


sub-section which cross the

Project Area.


river.

Mild Likely Moderate / low risk





Buried waste of

unknown provenance

within and

surrounding the

historic landfills.







atmospheres




Project Area.




properties adjacent to the Project Severe Low likelihood Moderate risk




foundations Mild Low likelihood Low risk

Geological hazards

(ground stability)


structures Medium Unlikely Low risk


structures Medium Low likelihood Moderate / low risk












Construction Phase Impact Assessment

11.6.6 The soils and geology impact assessment has been undertaken by

comparing the potential land contamination risks at the baseline stage to

those predicted during construction; these are summarised by sub-section

in Table 11.33 to Table 11.40. There is likely to be increased windblown

dust as a result of the stripping of topsoil, vegetation clearance,

earthworks and the movement of heavy plant. There is also the potential

for increased runoff with a high sediment load to impact surface water

receptors. The previously discussed mitigation measures are again

considered to ameliorate these impacts to an extent. A summary of the

impacts of the Project upon geology both as a resource and the physical

effects (ground stability) of the development subdivided by sub-section is

also discussed below each table.




Table 11.33 Construction Phase Land Contamination Impact Assessment for the Cherwell District Council sub-section

Potential linkage Baseline (current) risk assessment

Construction stage risk assessment

Comment Significance of effect

Exposure of off-site residents

to construction related

contaminated windblown

dust.

- Moderate / Low risk

Construction related contaminants

may have the potential to impact

off-site residents; dust control

measures assumed.

Minor adverse


to existing contaminants via

windblown dust.

Moderate/ Low risk Moderate / Low risk

Existing contamination could

potentially be mobilised during

earthworks. Dust control measures

assumed

Neutral

Exposure of construction

workers to construction

related contaminants

- Low risk

Construction workers are assumed

to be equipped with PPE and

adhering to safe systems of work.

Minor adverse


workers to existing

contamination disturbed

during earthworks

- Low risk

Construction workers are assumed

to be equipped with PPE and

adhering to safe systems of work.

Minor adverse

Pollution of surface water

courses Very low risk Low risk

It is assumed that best practice

working methods will be adhered

to.

Minor adverse

Pollution of groundwater Moderate/ Low Risk Low risk It is assumed that best practice

working methods will be adhered to Minor beneficial

Overall Assessment Minor adverse

effect




11.6.7 The construction phase impact assessment within the Cherwell District

Council sub-section has been undertaken by comparing the land

contamination risks at the baseline stage to those predicted during

construction informed by the specific conditions within this sub-section.

Overall there is predicted to be a minor adverse effect as a result of the

construction phase of works. The assumptions outlined at the beginning of

the chapter are likely to reduce the risks of potential contamination to the

identified receptors to a neutral level. The potential for the

removal/remediation of any encountered contamination sources is

considered a minor beneficial effect.

11.6.8 In terms of the risks to geology as a resource within this sub-section no

local geology sites or RIGs are located within 500 m of the Project

Boundary. A band of sub-alluvial inferred sand and gravel resource is

indicated to underlie the Project to the east of Bicester to the west of

Manor Farm, underlying approximately 300 m of the Project within this

sub-section. The widening of the railway as a result of the construction

phase is considered therefore to result in a minor sterilisation of a mineral

safeguarding area. There is the potential that existing contamination

encountered during the construction phase could also be mobilised and

impact the viability of identified mineral resources; this would be

considered a minor adverse effect owing to the limited extent of mineral

resources impacted.

11.6.9 The principal ground stability issues are related to the moderate hazard

posed by shrinking or swelling clays within the Cherwell District Council

sub-section. There are also areas of compressible ground identified

associated with mapped bands of superficial Alluvium. The earthworks

design for the Project will take adequate account of these risks therefore

the impact is considered to be Neutral.




Table 11.34 Construction Phase Impact Assessment for the Aylesbury Vale: Claydon/Quainton sub-section






contaminated windblown

dust.

- Moderate/ Low risk




measures assumed.

Minor adverse



windblown dust.

Moderate/ Low risk Moderate/ Low risk Dust control measures assumed Neutral




- Low risk

Construction workers are

assumed to be equipped with

PPE and adhering to safe

systems of work.

Minor adverse


workers to existing


during earthworks

- Low risk




systems of work.

Minor adverse


to landfill gas via the creation

of preferential pathways for

migration during works

Moderate risk Moderate risk

Any works undertaken in the

vicinity of the active landfill will be

coordinated with the landfill

operator. Should landfill waste be

encountered during the works

further advice must be sought.

Neutral


workers to landfill gas during

works

- Moderate risk

Where contractors are working in

areas with limited ventilation, in

close proximity to known landfills,

precautions such as the use of

LEL gas meters will be adopted.

Moderate adverse







The risks to built environment

receptors posed by the

creation of preferential

pathways for landfill gas

migration (explosion)

Low risk Low risk

There is the potential for the

creation of preferential pathways

for landfill gas migration during

the works.

Neutral




pathways for landfill leachate

migration

Low risk Low risk



for landfill leachate migration

during the works. Should leachate

be encountered further advice

should be sought.

Neutral





to in terms of fuel

storage/stockpiling of soils.

Minor adverse

Pollution of groundwater Moderate risk Moderate risk



to

Neutral

Overall Assessment Minor adverse effect




11.6.10 The construction phase impact assessment within the Aylesbury Vale:

Claydon/Quainton sub-section has been undertaken by comparing the

land contamination risks at the baseline stage to those predicted during


Owing to the close proximity of contemporary and historic landfills within

this sub-section the risks of construction workers encountering landfill gas

has been given a significance of moderate adverse; appropriate

consideration of this risk will be incorporated into the planning of work.

Overall there is predicted to be a minor adverse effect during the



identified receptors to neutral.



Boundary. Multiple bands of sub-alluvial inferred sand and gravel

resource are indicated beneath the Project to the east of Verney Junction,

underlying approximately 830 m of the sub-section. A band of River

Terrace deposits is indicated to the eastern extent of the sub-section and

underlying approximately 230 m of the Project. Brick clay is identified on

mineral safeguarding plans to underlie approximately 7 km of the eastern

extent of the sub-section. The widening of the railway as a result of the

construction phase, both in terms of the variety of resources impacted and

the total area underlain by identified mineral resources, is considered to

result in a moderate sterilisation of mineral resources, resulting in a

moderate adverse effect.

11.6.12 The principal ground stability issues identified within this sub-section are

related to the moderate hazard posed by shrinking or swelling clays. Two

areas along the route from Claydon Junction to Aylesbury have also been

designated a moderate risk of landslide; this appears related to the steep

topography of embankments in this area. The design of earthworks for the

Project will take adequate account of these risks, therefore the impact is

considered to be neutral.




Table 11.35 Construction Phase Impact Assessment for the Aylesbury Vale: Winslow/Swanbourne sub-section




Exposure of off-site

residents to construction

related contaminated

windblown dust.





measures assumed.

Minor adverse


residents to existing

contaminants via

windblown dust.

Low risk Moderate / Low risk Dust control measures assumed Minor adverse




- Low risk




systems of work.

Minor adverse


workers to existing


during earthworks

- Low risk






Minor adverse


residents to landfill gas via

the creation of preferential

pathways for migration

during works








Neutral








workers to landfill gas

during works

- Moderate risk






Moderate adverse

The risks to built

environment receptors

posed by the creation of


landfill gas migration

(explosion)

Low risk Low risk




the works.

Neutral

The risks to built




landfill leachate migration

Low risk Low risk






should be sought.

Neutral





to in terms of fuel


Minor adverse

Pollution of groundwater Moderate/ Low Risk Low risk



to

Minor beneficial






Winslow/Swanbourne sub-section has been undertaken by comparing the



Overall there is predicted to be a minor adverse effect during the

construction phase of works. The effects of construction workers

encountering landfill gas as a result of works in the vicinity of historic and

contemporary landfilling have been categorised as moderate adverse;

appropriate controls for this risk will be incorporated into the planning of

work. The assumptions outlined at the beginning of the chapter are likely

to reduce the risks of potential contamination to the identified receptors to

neutral.



Boundary. Multiple bands of glaciofluvial sand and gravel resource are

indicated to underlie approximately 1.8 km the Project in multiple areas

surrounding Winslow. A band of sub-alluvial sand and gravel is indicated

to the north of Winslow underlying approximately 1 km of the Project. The

widening of the railway as a result of the construction phase is considered

therefore to result in a minor sterilisation of mineral safeguarding areas,

resulting in a minor adverse effect.


related to the moderate hazard posed by shrinking or swelling clays.

Bands of alluvium have also been associated with a moderate risk of

compressible ground. The design of earthworks for the Project will take

adequate account of these risks therefore the impact is considered to be

neutral.




Table 11.36 Construction Phase Impact Assessment for the Aylesbury Vale: Aylesbury sub-section






related contaminants via

windblown dust.





measures assumed.

Minor adverse



contaminants via

windblown dust.

Low risk Moderate/ Low risk Dust control measures assumed Minor adverse




- Low risk




systems of work.

Minor Adverse


workers to existing


during earthworks

- Low risk




systems of work.

Minor Adverse





during works

Moderate Moderate







Neutral



during works

- Moderate risk





Minor adverse








The risks to built





(explosion)

Low risk Low risk




the works.

Neutral

The risks to built





Low risk Low risk






should be sought.

Neutral





to in terms of fuel


Minor adverse

Pollution of groundwater Moderate

risk Low risk



to

Minor beneficial






Aylesbury sub-section has been undertaken by comparing the land


construction, informed by the specific conditions within this sub-section.

No significant effects have been identified within this sub-section. Overall

there is predicted to be a minor adverse effect during the construction

phase of works. The assumptions outlined at the beginning of the chapter

are likely to reduce the risks of potential contamination to the identified

receptors to neutral.




indicated to underlie approximately 4.9 km of the Project north of

Waddesdon and Fleet Marston Farm. River terrace deposits underlie the

approximately 370 m of the Project to the north west of Quarrendon. The

widening of the railway as a result of the construction phase is considered

therefore to result in a minor sterilisation of a mineral safeguarding area,

resulting in a minor adverse effect.






neutral.




Table 11.37 Construction Phase Impact Assessment for the Wycombe District Council sub-section




Exposure of off-site residents to

construction related

contaminants via windblown

dust.

- Moderate/ Low risk Construction related contaminants

may have the potential to impact off-

site residents; dust control measures

assumed.

Minor adverse


existing contaminants via

windblown dust.



workers to construction related

contaminants

- Low risk Construction workers are assumed to

be equipped with PPE and adhering

to safe systems of work.

Minor adverse


workers to existing

contamination disturbed during

earthworks

- Low risk Construction workers are assumed to

be equipped with PPE and adhering

to safe systems of work.

Minor adverse


landfill gas via the creation of



Moderate risk Moderate risk Any works undertaken in the vicinity

of the active landfill will be

coordinated with the landfill operator.

Should landfill waste be encountered

during the works further advice must

be sought.

Neutral



works

- Moderate risk Where contractors are working in

areas with limited ventilation, in close

proximity to known landfills,

precautions such as the use of LEL

gas meters will be adopted.

Moderate adverse








receptors posed by the creation


landfill gas migration (explosion)

Low risk Low risk There is the potential for the creation

of preferential pathways for landfill

gas migration during the works.

Neutral





Low risk Low risk There is the potential for the creation

of preferential pathways for landfill

leachate migration during the works.

Should leachate be encountered

further advice should be sought.

Neutral


courses

Very low risk Low risk It is assumed that best practice

working methods will be adhered to

in terms of fuel storage/stockpiling of

soils.

Minor adverse

Pollution of groundwater Moderate risk Moderate risk It is assumed that best practice

working methods will be adhered to

Neutral

Overall Assessment Minor adverse

effect




11.6.19 The construction phase impact assessment within the Wycombe District




The risks of landfill gas to construction workers has been rated as

moderate owing to an identified landfill in close proximity to the Project

within Princes Risborough; however no work is proposed to take place in

this location therefore this risk is likely to be neutral. Overall there is

predicted to be a minor adverse effect during the construction phase of

works. The assumptions outlined at the beginning of the chapter are likely

to reduce the risks of potential contamination to the identified receptors to

neutral.




indicated to underlie the Project to the northern extent of the sub-section,

underlying approximately 150 m of the Project within this sub-section. A

narrow band of River Terrace deposits is indicated to intersect with the

Project adjacent to the northern boundary of the sub-section. An area of

low purity Chalk 93-98% is indicated to underlie approximately 3.9 km of

the Project surrounding Princes Risborough. The limited works currently

proposed within this sub-section during the construction phase is

considered therefore to result in a minor sterilisation of a mineral

resource, resulting in a minor adverse effect.


related to bands of alluvium which have been associated with a moderate

risk of compressible ground. The design of earthworks for the Project will

take adequate account of these risks therefore the impact is considered to

be neutral.




Table 11.38 Construction Phase Impact Assessment for the Milton Keynes Council sub-section







dust.

- Moderate / Low risk Construction related

contaminants may have the

potential to impact off-site

residents; dust control measures

assumed.

Minor adverse



windblown dust.




contaminants

- Low risk Construction workers are



systems of work.

Minor adverse


workers to existing


earthworks

- Low risk Construction workers are



systems of work.

Minor adverse





Moderate risk Moderate risk Any works undertaken in the

vicinity of the active landfill will

be coordinated with the landfill

operator. Should landfill waste

be encountered during the

works further advice must be

sought.

Neutral









works

- Moderate risk Where contractors are working

in areas with limited ventilation,

in close proximity to known

landfills, precautions such as the

use of LEL gas meters will be

adopted.

Moderate adverse





(explosion)

Moderate risk Low risk There is the potential for the



the works.

Minor beneficial





Moderate risk Low risk There is the potential for the



during the works. Should

leachate be encountered further

advice should be sought.

Neutral


courses

Very low risk Low risk It is assumed that best practice

working methods will be

adhered to in terms of fuel


Minor adverse

Pollution of groundwater Moderate risk Moderate risk It is assumed that best practice


adhered to

Neutral





11.6.22 The construction phase impact assessment within the Milton Keynes




Due to the long history of mineral extraction and subsequent landfilling

within this sub-section the risks of landfill gas to construction workers

have been classified as moderate adverse. Any work undertaken in the

vicinity of known landfills should incorporate control measures for the

possibility of encountering landfill gas into the risk assessment. Overall

there is predicted to be a minor adverse effect during the construction

phase of works. The assumptions outlined at the beginning of the chapter

are likely to reduce the risks of potential contamination to the identified

receptors to neutral.

11.6.23 In terms of the risks to geology as a resource within this Sub-section no


Boundary. A narrow band of River Terrace sand and gravel resource is

indicated to underlie the Project to the north of the former Bletchley

Brickworks site in Newton Longville. As the route branches to the north of

Bletchley station it becomes underlain by bedrock deposits of Brick Clay

with multiple historic brickworks surrounding Milton Keynes. As the route

extends to the east of Bletchley it is underlain by River terrace deposits

and Brick Clay surrounding Fenny Stratford. Further to the east the former

Station Brick and tile works and the Woburn Sands brickworks historic

clay extraction sites have been identified. There is the potential for

extraction of further mineral reserves in this study area in the future,

however given the narrow Project Area and existing railway infrastructure,

it is unlikely that significant mineral resource sterilisation will occur.





account of these risks and therefore the impact is considered to be

neutral.




Table 11.39 Construction Phase Impact Assessment for the Central Bedfordshire Council sub-section







dust.

- Low risk

Construction related

contaminants may have the

potential to impact off-site

residents; dust control measures

assumed.

Minor adverse



windblown dust.

Low risk Low risk Dust control measures assumed Neutral




- Low risk




systems of work.

Minor adverse


workers to existing


during earthworks

- Low risk




systems of work.

Minor adverse







vicinity of the active landfill will

be coordinated with the landfill

operator. Should landfill waste

be encountered during the

works further advice must be

sought.

Neutral









works

- Moderate risk

Where contractors are working

in areas with limited ventilation,

in close proximity to known

landfills, precautions such as the

use of LEL gas meters will be

adopted.

Moderate adverse




pathways for landfill gas

migration (explosion)

Low risk Low risk




the works.

Neutral




pathways for landfill leachate

migration

Low risk Low risk




during the works. Should

leachate be encountered further

advice should be sought.

Neutral





adhered to in terms of fuel


Minor adverse

Pollution of groundwater Low risk Moderate risk



adhered to

Minor adverse





11.6.25 The construction phase impact assessment within the Central

Bedfordshire Council sub-section has been undertaken by comparing the



Owing to the history of mineral extraction and subsequent landfilling in the

vicinity of the Project the effects of exposure to landfill gases on

construction workers has been classified as moderate adverse. Any works

in the vicinity of the Project must incorporate considerations and controls

appropriate to the encounter of landfilled waste. Overall there is predicted

to be a minor adverse effect during the construction phase of works. The

assumptions outlined at the beginning of the chapter are likely to reduce

the risks of potential contamination to the identified receptors to neutral.



Boundary. An outcrop of the Lower Oxford Clay surrounding historic clay

pits adjacent to the Quest clay pit have been identified adjacent to the

Project. The Woburn Sands formation intersects with the Project Area to

the north of Aspley Guise. The limited proposed work within this sub-

section in the construction phase is considered to result in a neutral effect

on geology as a resource.




compressible ground. An area centrally has been designated as a

moderate landslide risk; this appears to be associated with an area of

unmapped superficial deposits and regional topography. The design of

earthworks for the Project will take adequate account of these risks

therefore the impact is considered to be neutral.




Table 11.40 Construction Phase Impact Assessment for the Bedford Borough Council sub-section






related contaminants via

windblown dust.


Construction related

contaminants may have

the potential to impact

off-site residents; dust

control measures

assumed.

Minor adverse



contaminants via

windblown dust.

Low risk Low risk Dust control measures

assumed Neutral




- Low risk

Construction workers

are assumed to be

equipped with PPE and

adhering to safe

systems of work.

Minor adverse


workers to existing


during earthworks

- Low risk

Construction workers

are assumed to be

equipped with PPE and

adhering to safe

systems of work.

Minor adverse





during works


Any works undertaken in

the vicinity of the active

landfill will be

coordinated with the

landfill operator. Should

landfill waste be

encountered during the

Neutral







works further advice

must be sought.



during works

- Moderate risk

Where contractors are

working in areas with

limited ventilation, in

close proximity to known

landfills, precautions

such as the use of LEL

gas meters will be

adopted.

Moderate adverse

The risks to built





(explosion)

- Low risk

There is the potential for

the creation of



during the works.

Minor adverse

The risks to built





Low risk Low risk

There is the potential for

the creation of


landfill leachate

migration during the

works. Should leachate

be encountered further

advice should be

sought.

Neutral

Pollution of surface water Very low risk Low risk It is assumed that best Minor adverse







courses practice working

methods will be adhered

to in terms of fuel

storage/stockpiling of

soils.

Pollution of groundwater Low/ Moderate Risk Low risk

It is assumed that best

practice working

methods will be adhered

to

Minor beneficial





11.6.28 The construction phase impact assessment within the Bedford Borough




The risks of landfill gas encounter to construction workers has been

assessed as a moderate adverse effect. The limited works proposed

currently within this sub-section would likely mitigate this potential effect to

neutral. Overall there is predicted to be a minor adverse effect during the



identified receptors to neutral.



Boundary. An outcrop area of Lower Oxford Clay surrounding historic clay

pits adjacent to Kempston Hardwick further to the north of Elstow the

route is underlain by river gravel resources. Owing to the limited works

currently proposed within this sub-section the effect on minerals as a

resource is considered to be neutral.






neutral.

Construction Phase Conclusions

11.6.31 The construction phase of works across the sub-sections is considered to

result in neutral to minor adverse effects to controlled waters, off-site

human health and built environment receptors. The exception to this are

the potential moderate adverse effects identified associated with

construction workers being impacted by exposure to landfill gas.

Insufficient information currently exists to adequately assess and mitigate

these risks; additional intrusive ground investigation will be undertaken in




order to characterise the risk and identify appropriate worker protection

measures (if required).

11.6.32 No RIGs or locally important geology sites have been identified within 500

m of the Project Boundary. There are instances of potential mineral

sterilisation as a result of land take required by the Project, particularly

surrounding Milton Keynes. However, the extent of additional land take

when compared to the baseline is considered minor owing to the

presence of the existing railway overlying much of these mineral

resources.

11.6.33 The principal ground stability issues identified across the Project is related

to the moderate hazard posed by shrinking or swelling clays associated

with the various members of the Oxford Clay formation. The earthworks

design for the Project will take this risk into consideration.

Operation

11.6.34 The following tables present the CSM findings for the operation phase.




Table 11.41 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Cherwell District Council sub-section


Residual

contaminants within

Made Ground of

unknown provenance

associated with the



Project Area.

Contaminants

introduced to the


oils for maintenance




and soil.

Inhalation of windblown dust.


properties.

Recreational users of land within

and adjacent to the Project Area

Mild Unlikely Very low risk



and soil.

Inhalation of vapours.

Maintenance workers Minor Unlikely Very low risk

Contaminants

introduced to the


oils for maintenance




off

Surface run-off



materials





service runs.


(Alluvial deposits)

Launton Brook and Langford

Brook

Minor Unlikely Very low risk

Geological hazards Collapsible ground Existing and new, on- and off-site

structures






(ground stability) Compressible ground Existing and new, on- and off-site

structures


risk


structures



structures



structures



structures





Table 11.42 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Claydon/Quainton sub-section


Residual

contaminants within

Made Ground of

unknown provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.

Inhalation of windblown dust.


properties.






dust and soil.



Contaminants

introduced to the






off

Surface run-off



materials



Ground and along



Multiple surface water courses as

listed in Table 11.14.



(Alluvium & River Terrace Deposits)


Infill material

associated with the










former Calvert clay

pits/brick works





atmospheres


Project Area.

Maintenance Workers Severe Low likelihood Moderate risk






Subsurface



Geological hazards

(ground stability)


structures



structures



structures



structures


risk


structures



structures


risk




Table 11.43 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Winslow/Swanbourne sub-section


Residual contaminants


unknown provenance

associated with the



Project Area.

Contaminants introduced

to the Project, e.g. fuel

and oils for construction


Dermal contact/

ingestion/ inhalation of

contaminated dust and

soil.

Inhalation of windblown

dust.


properties.




Dermal contact/

ingestion/ inhalation of

contaminated dust and

soil.








silts into surface run-off

Surface run-off

Migration of

contaminants through

granular or fractured

materials



Made Ground and along

preferential pathways

e.g. newly-created

service runs.

Horwood Brook

Unnamed minor watercourse to the

east of Whaddon Road.



Buried waste of unknown Migration of ground gas Built environment receptors: Mild Low likelihood Low risk





provenance at the active

landfill at Newton

Longville Project and the


landfills.

through permeable

ground/ utility corridors/

cracks in floor slabs/


potential accumulation

to explosive

atmospheres



Project Area.

Maintenance workers Severe Low likelihood Moderate risk




Migration of landfill

leachate into the Project

Area

Subsurface



Geological hazards

(ground stability)


structures



structures

Medium Low Moderate / low

risk


structures



structures



structures



structures

Medium Low Moderate / low

risk




Table 11.44 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Aylesbury Vale: Aylesbury sub-section

Source of risk Pathway / action Receptor Consequence

Probability Risk

Residual

contaminants within

Made Ground of

unknown provenance

associated with the



Project Area.

Contaminants

introduced to the






and soil.


properties.




and soil.


Construction/Maintenance

workers


Contaminants

introduced to the






off

Surface run-off







service runs.

Fleet Marston Brook

the River Thame

Bear Brook

Coldharbour Way Ditch,

California Brook

Stoke Brook



Bedrock Principal & Secondary A

aquifers


risk

Buried waste of

unknown provenance













Probability Risk

Area including

Channel Infill

associated with the

River Thame.



atmospheres

Project Area.

Maintenance workers Severe Low likelihood Moderate risk





the Project Area

Subsurface



Geological hazards

(ground stability)


structures



structures


risk


structures



structures



structures



structures


risk




Table 11.45 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Wycombe District Council sub-section


Residual

contaminants within

Made Ground of

unknown provenance

associated with the



Project Area.

Contaminants

introduced to the






dust and soil.


properties.

Mild Low likelihood Very low risk



dust and soil.


Maintenance workers Minor Low likelihood Very low risk

Contaminants

introduced to the






off

Surface run-off



materials





service runs.


Brook


Superficial Secondary A & Principal

Bedrock aquifers


risk





Buried waste of

unknown provenance






utility corridors/ cracks in floor

slabs/ service entry points with






Project Area.


Maintenance workers Severe Unlikely Moderate/low

risk



Area

Severe Unlikely Moderate/low

risk



Subsurface



Geological hazards

(ground stability)


structures



structures


risk


structures



structures



structures



structures





Table 11.46 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Milton Keynes Council sub-section


Probability Risk



unknown provenance

associated with the



Project Area.







dust and soil.


properties.




dust and soil.









Surface run-off


through granular or

fractured materials







Lagoon LNR, Caldecotte Lake and

the Grand Union Canal


Superficial & Bedrock Secondary A

aquifers


risk

Buried waste of unknown

provenance at the active

landfill at Newton

Longville Project and








Project Area.






Probability Risk


landfills.



atmospheres


risk



Area


risk



Area

Subsurface infrastructure/foundations Mild Low likelihood Low risk

Geological hazards

(ground stability)


structures



structures


risk


structures



structures



structures



structures





Table 11.47 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Central Bedfordshire Council sub-section


Probability Risk



unknown provenance

associated with the



Project Area.







dust and soil.


properties.




dust and soil.


Maintenance workers Mild Unlikely Very low risk







Surface run-off



materials



Ground and along



Controlled waters: The Broughton

Brook (ordinary watercourse)


Superficial Secondary A aquifer Mild Low likelihood Low Risk


provenance within the


landfills.








Project Area.






Probability Risk



atmospheres

Exposure of maintenance workers

to landfill gas.


risk



Area

Severe Unlikely Moderate risk



Subsurface



Geological hazards

(ground stability)


structures



structures


risk


structures



structures



structures



structures





Table 11.48 Operational Phase Conceptual Site Model Findings: Potential Contaminant Linkages Associated with the Project within the Bedford Borough Council sub-section



Made Ground of unknown

provenance associated

with the historical uses of

the land surrounding the

Project Area.


to the Project, e.g. fuel and

oils for construction plant

and equipment.



dust and soil.


properties.




dust and soil.




to the Project, e.g. fuel and

oils for construction plant

and equipment.



Surface run-off


through granular or

fractured materials





newly-created service

runs.


Secondary A and bedrock Principal

aquifers


sub-section which cross the Project

Area.


river.

Medium Low likelihood Moderate/low

risk






provenance within and

surrounding the historic

landfills.


through permeable

ground/ utility corridors/

cracks in floor slabs/







Project Area.

Severe Unlikely Moderate/Low

risk


risk



Area


risk



Area

Subsurface infrastructure/foundations Mild Low likelihood Low risk

Geological hazards

(ground stability)


structures



structures


risk


structures



structures



structures



structures





Operation Phase Impact Assessment

11.6.35 The operational phase impact assessment has been undertaken by

comparing the land contamination risks at the baseline stage to those

predicted during operation for each sub-section. This is summarised by

sub-section within Table 11.49 to Table 11.56. As during the construction

phase several assumptions have been incorporated regarding the finished

condition of the Project:

Contaminated arisings from construction will be appropriately managed and removed from the Project Area following construction;

All potentially contaminative construction-related materials (fuels / chemicals / paints / stockpiled soils) would be removed from the Project Area;

Bare soils will be re-vegetated as part of the Project completion; any contamination encountered will be bunded and sealed / sheeted prior to removal from site

Detailed control measures will be included in risk assessments. Primary control will be to prevent exposure by careful selection of materials, safety / COSHH briefing will form part of task briefings and suitable PPE provided;

Bunds, cut-off ditches, settlement lagoons, segregation of refuelling etc. will be employed to protect surface and groundwater receptors from e.g. spillages and silt;

Material will be subject to contamination identification and treatment prior to commencement; site workers will be briefed on visual signs of contamination; and

Construction work areas within the Project Area will be fenced preventing access.




Table 11.49 Operational Phase Impact Assessment for the Cherwell District Council sub-section


Operational stage risk assessment





dust.

- Very low risk See above assumptions. Neutral


to residual contaminants via

windblown dust.

Moderate / Low risk Very low risk See above assumptions. Neutral



contaminants

- Very low risk See above assumptions. Neutral


workers to residual


earthworks

- Very low risk See above assumptions Neutral


courses

Very low risk Very low risk See above assumptions. Neutral

Pollution of groundwater Moderate Very low risk See above assumptions Minor beneficial

Overall Assessment Neutral effect




Table 11.50 Operational Phase Impact Assessment for the Aylesbury Vale: Claydon/Quainton sub-section







dust.




windblown dust.

Moderate / Low Very low risk See above assumptions Minor beneficial



contaminants






Moderate risk Moderate risk See above assumptions Neutral

Exposure of construction /

maintenance workers to landfill

gas during works

- Moderate risk See above assumptions Neutral





(explosion)

Low risk Low risk See above assumptions Neutral













workers to residual


earthworks



courses

Very low risk Very low risk See above assumptions Neutral






Table 11.51 Operational Phase Impact Assessment for the Aylesbury Vale: Winslow/Swanbourne sub-section







dust.




windblown dust.

Low risk Very low risk See above assumptions Minor beneficial



contaminants









works






(explosion)














workers to residual


earthworks



courses


Pollution of groundwater Low Very low risk See above assumptions Minor beneficial





Table 11.52 Operational Phase Impact Assessment for the Aylesbury Vale: Aylesbury sub-section







dust.




windblown dust.




contaminants









works






(explosion)












Low risk Low risk See above assumptions. Neutral


workers to residual


earthworks



courses


Pollution of groundwater Moderate Very low risk See above assumptions Neutral





Table 11.53 Operational Phase Impact Assessment for the Wycombe District Council sub-section







dust.




windblown dust.

Low risk Very low risk See above assumptions Neutral



contaminants









works






(explosion)














workers to residual


earthworks



courses







Table 11.54 Operational Phase Impact Assessment for the Milton Keynes Council sub-section







dust.




windblown dust.




contaminants









works






(explosion)












Moderate risk Low risk See above assumptions Neutral


workers to residual


earthworks



courses







Table 11.55 Operational Phase Impact Assessment for the Central Bedfordshire Council sub-section







dust.




windblown dust.




contaminants









works






(explosion)














workers to residual


earthworks



courses


Pollution of groundwater Low risk Very low risk See above assumptions Minor beneficial





Table 11.56 Operational Phase Impact Assessment for the Bedford Borough Council sub-section







dust.




windblown dust.




contaminants









works






(explosion)














workers to residual


earthworks



courses


Pollution of groundwater Very low risk Very low risk See above assumptions Neutral





Operational Phase Conclusion

Mineral Resources (a)

11.6.36 The operational phase impact assessment has not identified any potential

significant loss of mineral resource on completion.

Physical Effects (Stability) (b)

11.6.37 Design of the Project engineering will take in to account the particular

ground stability conditions, therefore resulting in no anticipated impact at

operation stage.

Potential for Contamination introduction / mobilisation (c)

11.6.38 The operational phase impact assessment has been undertaken by

comparing the land contamination risks at the baseline stage to those

predicted during the operation of the Project. It is anticipated that there

will be no change to the baseline condition as a result of the development

as a result of embedded mitigation measures incorporated into the

Project. The mitigation measures in isolation may not however be

sufficient to lower the risk levels in every instance as (assuming the worst

case) contamination will remain and some pathways will still exist.

11.6.39 With mitigation incorporated into the design of the Project, a minor

beneficial effect is anticipated associated with the removal/remediation of

encountered on-site contamination as well as improvements to the Project

drainage systems. The anticipated minor beneficial and neutral effects

are considered to be not significant.

Waste soils and material re-use (e)

11.6.40 The conclusions for this part of the assessment will be presented in the

final ES.

11.7 Mitigation

11.7.1 Given the incorporated mitigation outlined in Section 11.3 and that the

ground conditions and contamination effects are assessed as neutral and

not significant, no further mitigation is required.




11.8 Residual Effects

11.8.1 With no further mitigation considered to be required the residual effects for

construction and operation of the Project are as reported above.

Documents

TRANSPORT AND WORKS ACT 1992 Transport and Works ...... · Procedure) (England and Wales) Rules 2006 THE NETWORK RAIL (EAST WEST RAIL WESTERN SECTION PHASE 2) ORDER DRAFT ENVIRONMENTAL