crossrail environmental statement…seven kings station 162 3.6 route window ne6: goodmayes station...

Crossrail Environmental Statement

Volume 6aAppendicesB1: Construction mitigation measuresB2: Listed buildings and settlementB3: Noise and vibrationB4: Air qualityB5: Local planning policies

6a

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Crossrail Environmental Statement

Volume 6a

Prepared for The Department for Transport by Environmental Resources Management

Contents

Appendix B1

Construction mitigation measures 1

1 General Site Operations 2

1.1 Working Hours 2

1.2 Electromagnetic Interference 3

1.3 Site Lighting 3

1.4 Unexploded Ordnance 3

2 Public Access and Highway 4

2.1 Traffic Management Plan 4

2.2 Works Affecting Highways andPublic Rights of Way 4

2.3 Road Cleanliness 4

2.4 Lorry Controls 5

3 Noise and Vibration 6

3.1 Specific Provisions 6

General 6

Selection and Use of Equipment 6

Approach to the Selection of Mitigation 7

Provision of Noise Insulation orTemporary Rehousing 8

Vibration 9

4 Air Quality 10

4.1 Vehicle and Plant Emissions 10

4.2 Dust 10

Overview 10

Standard Dust Control Procedures on Sites with a Low Risk of DustEmissions (Tier 1) 11

Enhanced Dust Control Procedures on Sites with an Medium or High Risk of Dust Emissions (Tier 2) 13

Advanced Dust Control Procedures on Sites with a High Risk of DustEmissions (Tier 3) 13

4.3 Asbestos 14

5 Water Resources 15

5.1 Procedures 15

Assessment and Planning 15

Site Drainage 15

5.2 Protection of Watercourses 15

5.3 Control of Pollution of Surface Water 16

5.4 Control of Pollution of Groundwater 17

5.5 Mitigation of Impacts at Abstraction Boreholes 17

5.6 Dewatering 17

5.7 Monitoring and Mitigation of Water Levels in the Shallow Aquifer 18

5.8 Dredging 18

6 Contaminated Land 19

6.1 Site Assessment and RemedialPractice 19

6.2 Remedial Techniques 20

7 Waste Management and Recycling 26

7.1 General 26


Site Waste Management Plan 26

Duty of Care 26

Specific Provisions/Measures Available 27

8 Ecology and Nature Conservation 28

8.1 General Provisions 28

8.2 Mitigation Specific to Bats 29

Introduction 29

General Procedures for All Works 30

Specific Procedures 30

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8.3 Mitigation Specific to Reptiles 32

Overview 32

General Procedures 33

8.4 Mitigation Specific to Great Crested Newts 34

8.5 Mitigation Specific to Water Voles 34

Overview 34

Off-site Relocation 35

Long Term Holding 35

Exclusion from Habitat Creation Areas 35

8.6 Protection of Trees 36

9 Archaeology and Heritage 37

9.1 Procedures 37


10 Settlement 39


General 39

Provisions in Relation to Listed Buildings 40

Appendix B2

Listed buildings and settlement 41

Appendix B3

Noise and vibration 57

Preface 59

Appendix B4

Air quality 85

1 Air quality: Central Route Section 86

1.1 Route Window C1: Royal Oak Portal 86

1.2 Route Window C2: Paddington Station 87

1.3 Route Window C3: Hyde ParkVentilation Shaft & Park LaneVentilation Shaft 90

1.4 Route window C4: Bond Street Station 92

1.5 Route Window C5: Tottenham Court Road Station and FisherStreet Ventilation Shaft 95

1.6 Route Window C6: Farringdon Station 100

1.7 Route Window C7: Liverpool Street Station 103

1.8 Route Window C8: Whitechapel Station 106

1.9 Route Window C8A: Mile EndConveyor Corridor 110

1.10 Route Window C9: Stepney Green Ventilation Shaft 111

1.11 Route Window C10: Lowell Street Shaft 113

1.12 Route Window C11: Isle of Dogs Station 114

1.13 Route Window C12: Mile End Park and Eleanor Street Shaft 116

1.14 Route Window C13: Pudding Mill Lane Portal 117

1.15 Route Window C13A: Abbey Mills 120

2 Air Quality: Western Route Section 122

2.1 Route Window W25: Maidenhead Station 122

2.2 Route Window W24: Maidenhead Railway Bridge 123

2.3 Route Window W23: Taplow Station 123

2.4 Route Window W22: Lent Rise 123

Crossrail Environmental Statement Volume 6a iii

2.5 Route Window W21: Burnham Station 124

2.6 Route Window W20: Dover Road and Leigh Road Bridges 125

2.7 Route Window W19: Stoke Poges Lane Bridge 128

2.8 Route Window W18: Slough Station 129

2.9 Route Window W17: Downs, St.Mary's Road and Trenches Bridges 131

2.10 Route Window W16: Langley Station 133

2.11 Route Window W15: Dog Kennel Bridge 135

2.12 Route Window W14: Iver Station 136

2.13 Route Window W13: West Drayton Stabling and Sidings 137

2.14 Route Window W12: Horton Road and Old Stockley Road Bridges 138

2.15 Route Window W11: Stockley Flyover 140

2.16 Route Window W10: Hayes and Harlington Station 141

2.17 Route Window W9: Southall West Sidings 142

2.18 Route Window W8: Southall Station 143

2.19 Route Window W7: Hanwell Station 145

2.20 Route Window W6: West Ealing Station 146

2.21 Route Window W5: Ealing Broadway Station 147

2.22 Route Window W4: Acton Mainline and Yard 149

2.23 Route Window W3: Old Oak Common Depot 151

2.24 Route Window W2: Canel Way 152

2.25 Route Window W1: Ladbroke Grove 153

3 Air Quality: Northeastern Route Section 154

3.1 Route Window NE1: Stratford Station 154

3.2 Route Window NE2: Forest Gate Station 156

3.3 Route Window NE3: Manor Park Station 158

3.4 Route Window NE4: Ilford Station 160

3.5 Route Window NE5: Seven Kings Station 162

3.6 Route Window NE6: Goodmayes Station 163

3.7 Route Window NE7: Chadwell Heath Station 164

3.8 Route Window NE8: Romford Depot (West) 165

3.9 Route Window NE9: RomfordStation and Depot (East) 167

3.10 Route Window NE10: Gidea Park Station 169

3.11 Route Window NE11: Gidea Park Stabling 171

3.12 Route Window NE12: Harold Wood Station 172

3.13 Route Window NE13: LB Havering/Brentwood DCBoundary 173

3.14 Route Window NE14: Brook Street 173

3.15 Route Window NE15: Brentwood Station 173

3.16 Route Window NE16: Thrift Wood 174

3.17 Route Window NE17: Shenfield Station 174

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4 Air Quality: Southeastern Route Section 177

4.1 Route SE1: Blackwall Way & Limmo Peninsula Shafts 177

4.2 Route Window SE2: Custom House Station 178

4.3 Route Window SE3: Connaught Tunnel 180

4.4 Route Window SE4: North Woolwich Portal and Thames Tunnel 181

4.5 Route Window SE5: Arsenal Way Shaft 182

4.6 Route Window SE6: Plumstead Portal 183

4.7 Route Window SE6A: Manor Wharf 184

4.8 Route Window SE7: Church Manorway Bridge 185

4.9 Route Window SE8:Abbey Wood Station 186

Appendix B5

Local planning policies 189

Crossrail Environmental Statement:Planning Sources 190

Glossary of terms 193

Crossrail Environmental Statement Volume 6a v

Appendix B1

Construction mitigationmeasures

1 General Site Operations

1.1 Working Hours

1.1.1 Assumed working hours are assessed to be from 0700 to 1900 on weekdays and0700 to 1400 on Saturday. Only non-disruptive preparatory work, repairs ormaintenance will be carried out on Saturday afternoons (up to 1900) or Sundaysbetween 0800 and 1700. There are certain general exceptions to these hours, whichare described below. In addition, it may be necessary in exceptional cases of urgencyto depart from these hours.

1.1.2 Tunnelling works together with directly associated activities (such as installation andmaintenance of tunnelling equipment, construction of cross passages, installation oftunnel linings and transportation, storage and removal of excavated material) willnormally be carried out on a 24 hour per day, seven days per week basis. Track layingand internal fit-out works within the stations and tunnels may also be carried out on a24 hour per day, seven days per week basis.

1.1.3 In order to safeguard the works it may be necessary for certain items of plant andequipment to be kept running 24 hours per day, which would include pumps andgenerators. Any such equipment will be shielded, where required, in order to provideappropriate noise attenuation. Staff may be required to collect data and samplesoutside assumed working hours at times.

1.1.4 Certain works requiring temporary possession of roads and railways for safety oroperational requirements, to limit disruption to the travelling public, and works inconnection with utilities when demand is low will need to be undertaken outsideassumed working hours. This will include Saturday afternoon, night-time, Sundayand/or bank holiday working from time to time. Longer-term possessions (in excess ofone week) will be required for more major works.

1.1.5 In the case of work required in response to an emergency or which if not completedwould be unsafe or harmful to the permanent works or other infrastructure, the relevantlocal authority will be informed as soon as reasonably practicable of the reasons for,and likely duration of, the works. The local authority will provide a telephone numberand nominate an office to receive such notification, which will be reviewed regularly.Examples of the type of work envisaged would include where pouring concrete takeslonger than planned due to equipment failure or where unexpected poor groundconditions, encountered whist excavating, require immediate stabilisation.

1.1.6 Where work has to be rescheduled for reasons not envisaged and is expected toextend beyond the agreed or assumed working hours or exceed the agreed limitsunder the Section 61 consent of the Control of Pollution Act 1974, the nominatedundertaker or any contractor will apply for a variation to the Section 61 consent to therelevant local authority at least 14 days in advance of the start of those works.

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1.1.7 Where rescheduling relates to work of a critical nature (such as key activities likely todelay other key activities) applications will be made where practicable at least 48 hoursin advance and at least 7 days in advance if the work is expected to last for a period of5 days or more. The variation will be sought by means of an application setting out therevised construction programme or method and the relevant noise calculations.

1.1.8 Where such working outside assumed working hours has been discussed andaccepted (as in paragraph 1.1.7 above) nearby occupiers who are likely to be affectedby the works will be informed as soon as reasonably practicable about the nature andlikely duration of the works.

1.1.9 Deliveries will be arranged to minimise impacts on the road system as far as reasonablypracticable. Abnormal loads may be delivered or removed outside assumed workinghours subject to the requirements and approval of the relevant authorities.

1.2 Electromagnetic Interference

1.2.1 The effects of electromagnetic interference on wireless telecommunication systems willbe considered during the design and construction of Crossrail, which will include sitespecific effects from the demolition of buildings and the installation of tower cranes.

1.3 Site Lighting

1.3.1 Site lighting and signage will be provided to ensure the safety and security of theconstruction sites and will be at the minimum luminosity necessary. Where appropriate,lighting to site boundaries will be provided and illumination will be sufficient to provide asafe route for the passing public. In particular, precautions will be taken to avoidshadows cast by the site hoarding on surrounding footpaths, roads and amenity areas.

1.3.2 Appropriate industry standard procedures will be implemented at all construction sitesfor site lighting. This will include lighting being positioned and directed so as not tounnecessarily intrude on adjacent buildings and land uses and so as to preventunnecessary interference with local residents, railway operations, passing motorists, orthe navigation lights for air or water traffic. This provision will apply particularly to siteswhere night working will be required. In addition, at construction sites where potentiallysignificant impacts are identified, a lighting management plan will be prepared andimplemented.

1.4 Unexploded Ordnance

1.4.1 A risk assessment will be completed for the possibility of unexploded ordnance beingfound on the various sites and a response process will be included in the emergencyprocedures. An emergency response procedure will be prepared and implemented torespond to unexploded ordnance.

Crossrail Environmental Statement Volume 6a 3

2 Public Access and Highway

2.1 Traffic Management Plan

2.1.1 A Traffic Management Plan (TMP), or plans, will be produced and implemented. Theplan will be prepared in consultation with highway and traffic authorities and theemergency services.

2.1.2 The TMP will include, as appropriate:

• site boundaries and the main access/egress points for the worksites;

• temporary and permanent closures and diversions of highways and public rights of way;

• the strategy for traffic management; and

• local routes to be used by traffic generated by construction activity, including lorryholding areas, means of monitoring lorry use and any routes prohibited from use.

2.2 Works Affecting Highways and Public Rights of Way

2.2.1 The nominated undertaker or any contractor will consult with the relevant local authoritybefore commencing works that will involve interference with a highway or public right ofway. All necessary consents and licences will be obtained in advance.

2.2.2 All temporary closures of highways and public rights of way will be for as short a timeas reasonably practicable. Pedestrian access to premises will be maintained.

2.2.3 As far as reasonably practicable, diverted rights of way will be provided prior to the commencement of the relevant parts of the works and will be maintained to acomparable standard of those that they replace. Suitable signage and barriers will be provided.

2.2.4 Local residents and businesses will be informed in advance of the dates and durationsof closures and will be provided with details of diversion routes.

2.3 Road Cleanliness

2.3.1 All reasonably practicable measures will be put in place to mitigate the deposition ofmud and other debris on the highway. These measures will have regard to the natureand the use of the site and could include:

• hardstanding at the access and egress points which will be cleaned at appropriate intervals;

• vehicle wash down points to clean vehicle wheels at each exit point on to the highway;

• the correct loading of vehicles and sheeting of loads where necessary to avoid spillage during their journeys; and

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• the use of mechanical road sweepers combined with water sprays for thesuppression of dust to clean site hardstandings and roads and footpaths in thevicinity of the site.

2.3.2 After completion of any works affecting a highway, all surplus materials arising from theworks will be cleared from the highway, leaving it in a clean and tidy condition inaccordance with the reasonable requirements of the highway authority.

2.4 Lorry Controls

2.4.1 Construction access/egress routes will be designated in accordance with proceduresset down in any Act resulting from the Bill.

2.4.2 As far as reasonably practicable, there will be no parking of lorries on the highway in thevicinity of any worksite except in specified holding areas for lorries waiting to deliver orremove materials from the site.

2.4.3 An appropriate control system will be implemented for the dispatch of all vehiclescontaining excavated material, demolition materials or other waste material. Waste willbe controlled and deposited in accordance with relevant legislation.

2.4.4 Signs will be displayed in a prominent position on vehicles on public roads which are dedicated to the Crossrail project. The signs will uniquely identify the vehicle to Crossrail.


3 Noise and Vibration

3.1 Specific Provisions

General

3.1.1 The noise and vibration impacts associated with the construction of Crossrail have beenassessed assuming that particular mitigation measures and controls are applied to allplant and activities at each worksite individually. For this reason the mitigation measuresand controls applied differ from worksite to worksite. The mitigation measures andcontrols, which have been assumed for the assessment and which will be adopted onthe various work sites, have been drawn from the range of controls described below.

Selection and Use of Equipment

3.1.2 The nominated undertaker or any contractor will require that that each item of plantused on the project complies with the noise limits quoted in the relevant EuropeanCommission Directive 2000/14/EC and United Kingdom Statutory Instrument (SI)2001/1701, The Noise Emission in the Environment by Equipment for use OutdoorsRegulations 2001.

3.1.3 The nominated undertaker or any contractor will adopt the recommendations set out inAnnex B of Part 1 of BS 5228 and Sections 7.3 and 9.2 of Part 4 of BS 5228 withregard to noise and vibration mitigation options.

3.1.4 Plant and equipment liable to create noise and/or vibration whilst in operation will, as faras reasonably practicable, be located away from sensitive receptors. The use of barriersto absorb and/or deflect noise away from noise sensitive areas will be employed whererequired and reasonably practicable.

3.1.5 All plant, equipment and noise control measures applied to plant and equipment shall bemaintained in good and efficient working order and operated such that noise emissionsare minimised as far as reasonably practicable. Any plant, equipment or items fitted withnoise control equipment found to be defective will not be operated until repaired.

3.1.6 Where reasonably practicable, fixed items of construction plant should be electricallypowered in preference to diesel or petrol driven.

3.1.7 Machines in intermittent use should be shut down or throttled down to a minimumduring periods between work. Static noise-emitting equipment operating continuouslywill be housed within suitable acoustic enclosure, where appropriate.

3.1.8 For underground activities, measures to be considered for limiting noise will include one ormore of the following, where reasonably practicable and appropriate, as set out below:

Conveyor

• The mounting for conveyors used to remove excavated material from the tunnel facewill be designed and installed so as to mitigate the transmission of groundbornenoise and vibration to buildings above the tunnel;

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• A maintenance programme will be implemented to ensure that the noise generationof the conveyor does not deteriorate over time; and

• The surface conveyor systems will be of a similar standard to underground conveyorsand will be acoustically enclosed where it they run through or adjacent to noisesensitive areas. They too will be the subject of a maintenance programme.

Temporary Construction Railway

• New rail (smooth track without corrugations or discrete irregularities) will be installedat the start of the works with joints achieving variations in rail height of not more than2mm. The rail will be relocated as the location of temporary railway is altered duringthe construction of the works. The rail will be fastened to sleepers using resilient railpads, or adequate elasticity to the support of the track system, between the rail footand the sleeper, or tunnel invert, in order to reduce the transmission of vibration andgroundborne noise from the passage of rail vehicles, where appropriate.

• A speed limit on construction trains of 15 km per hour will be imposed.

• All diesel locomotives used are fitted with efficient exhaust silencers.

• A maintenance programme will be operated to ensure that the condition of the trackdoes not deteriorate over time thereby causing noise. The maintenance programmewill also help to reduce the occurrence of wheel squeal or flattening of wheels thatmight otherwise develop over time.

Temporary Tunnel Ventilation

• All tunnel ventilation plant with connections to the atmosphere in any noise-sensitivelocation will be subject to mitigation measures appropriate to its local environment.

Approach to the Selection of Mitigation

3.1.9 The modelling and assessment of construction noise has been based upon theprovision of three tiers of on-site mitigation. These have been designed to applyincreasing levels of control to each worksite allowing the reduction of the numbers ofproperties subject to significant impact and also the numbers of buildings that may beeligible for noise insulation (NI) or temporary re-housing (TRH). The tiers are as follows:

• Tier 1 – The provision of conventional on-site mitigation consisting of: 2.4 m highhoardings; use of low noise, well maintained plant, plant to be in compliance with thelatest EC Directive and amendments (eg Directive 2000/14/EC of the EuropeanParliament and of the Council of 8 May 2000 on the approximation of the laws of theMember States relating to the noise emission in the environment by equipment foruse outdoors); and the use of local noise screens, barriers and enclosures, includingthe sheeting of buildings during the demolition phase, as practicable.

• Tier 2 – The provision of all of the above plus the raising of hoarding heights to 3.6 m,or in some cases 5.0 m, and the enclosure of major, noisy items of plant (groutpumps, ventilation fans, concrete lorry unloading areas, etc).

• Tier 3 – The provision of all the above plus total enclosure of all or parts of sites for allor part of the construction programme, as practicable.


3.1.10 The transition through the above tiers is dependent upon the severity of impactforecast, including the duration, associated with works at each site. Where significantimpacts have been predicted and/or significant numbers of buildings were likely to beeligible for NI or TRH, then the next tier of mitigation was adopted.

Provision of Noise Insulation or Temporary Rehousing

3.1.11 Where, in spite of the measures set out above and any Section 61 consents, noiselevels at some properties are expected to exceed the trigger levels for the periodsdefined below, a scheme for the installation of noise insulation or the reasonable coststhereof, or a scheme to facilitate temporary rehousing of occupants, as appropriate, willbe implemented. The scheme will include provision for the notification of affected parties.

3.1.12 Noise insulation or the reasonable costs thereof will be offered to owners, where appliedfor by owners or occupiers, subject to meeting the other requirements of the proposedscheme, if either of the following apply to a property lawfully occupied as a permanentdwelling:

• the Predicted Noise Level exceeds the Noise Insulation Trigger Level, as presented inTable 3.1; or

• where the total noise (pre-existing ambient plus airborne construction noise) is 5 dBabove the existing airborne noise level for the corresponding times of day, whicheveris the higher; and

• for a period of 10 or more days of working in any 15 consecutive days or for a totalof days exceeding 40 in any six-month period.

Table 3.1 Airborne Noise Trigger Levels for Sound Insulation

Note 1: All noise levels are predicted or measured at a point one metre in front of the most exposed ofany windows and doors in any facade of an eligible dwelling.

Time Relevant Time Period

Averaging Time T

Noise Insulation Trigger Level

dB LAeq, T (1)

Monday to Friday 07:00 – 08:0008:00 – 18:0018:00 – 19:0019:00 – 22:0022:00 – 07:00

1 hr10 hr1 hr3 hr1 hr

7075706555

Saturday 07:00 – 08:0008:00 – 13:0013:00 – 14:0014:00 – 22:0022:00 – 07:00

1 hr5 hr1 hr3 hr1 hr

7075706555

Sunday and PublicHolidays

07:00 – 21:0021:00 – 07:00

1 hr1 hr

6555

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3.1.13 Temporary rehousing, or the reasonable costs thereof, will be provided, where appliedfor by legal occupiers, subject to meeting the other requirements of the proposedscheme, where the construction of the railway causes, or is expected to cause,construction noise levels to exceed whichever is the higher of either:

• 10 dB above any of the noise levels in Table 3.1; or

• 10 dB above the existing airborne noise level for the corresponding time of day,whichever is the higher; and

• for a period of 10 or more days of working in any 15 consecutive days or for a totalof days exceeding 40 in any six-month period.

3.1.14 Buildings which may be particularly sensitive to noise (these include commercial andeducational establishments, hospitals and clinics) will be subject to individualconsideration by the nominated undertaker, upon application by the affected party.

Vibration

3.1.15 With respect to vibration, where there are buildings that are attached or contiguous to buildings that are proposed for demolition, the attached or contiguous buildings willbe unattached, as far as possible, using non-vibratory techniques, such as diamondsawing. These techniques will be undertaken before demolition commences and as it progresses.

3.1.16 Prior to the commencement of works, appropriate plant and working methods will beidentified based on predicted vibration levels. An appropriate continuous vibration-monitoring regime will be adopted during the works to allow monitoring of levels andcessation of activity if levels potentially exceed the limits.


4 Air Quality

4.1 Vehicle and Plant Emissions

4.1.1 There are a number of measures that may be utilised to reduce vehicle and plantemissions arising from the project. Set out below are the measures that have beenassumed for the purposes of the assessment:

• using low emission vehicles and plant fitted with catalysts, diesel particulate filters orsimilar devices;

• requiring that plant will be well maintained, with routine servicing of plant and vehiclesto be completed in accordance with the manufacturer’s recommendations andrecords maintained for the work undertaken;

• requiring that all project vehicles, including off-road vehicles, hold current MOTcertificates, where required due to the age of the vehicle, (or to be tested to anequivalent standard) and that they will comply with exhaust emission regulations fortheir class;

• avoiding the use of diesel or petrol powered generators and using mains electricity orbattery powered equipment; and

• maximising energy efficiency (this may include using alternative modes of transport,maximising vehicle utilisation by ensuring full loading and efficient routing).

4.1.2 In addition, the following measures could also be utilised if necessary and reasonablypracticable (these have not been taken into account in the assessment):

• ensuring that the engines of all vehicles and plant on-site are not left runningunnecessarily;

• using ultra low sulphur fuels in plant and vehicles; and

• siting haul routes and operating plant away from potential receptors such as houses,schools and hospitals.

4.2 Dust

Overview

4.2.1 Dust management plans will be prepared and implemented for each worksite, includingcontrols to limit dust emissions. Three levels of control for dust effects are planned, withthe standard level, Tier 1, as the minimum that will be implemented on any site. A risk-based approach will be used to identify construction sites with potential to generatesignificant quantities of dust near sensitive receptors and which require additional levelsof control, Tier 2 or 3. The nominated undertaker or any contractor will employtechniques detailed in the following paragraphs. The techniques are cumulative, whichmeans that for Tier 3 control, all of the techniques from Tiers 1 to 3 will be required.These techniques are in line with the Building Research Establishments publication‘Controlling particles, vapour and noise pollution from construction sites’ (2003), whichwill be used as a reference for dust control on site.

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Standard Dust Control Procedures on Sites with a Low Risk of Dust Emissions(Tier 1)

4.2.2 The standard dust control procedures, Tier 1, will include, as appropriate, site controls to:

• ensure no burning of waste materials takes place on site;

• ensure an adequate water supply on the site;

• ensure disposal of run-off water from dust suppression activities, in accordance with the appropriate legal requirements;

• maintain all dust control equipment in good condition and record maintenance activities;

• keep site fencing, barriers and scaffolding clean using only wet methods;

• provide easily cleaned hardstanding for vehicles, where reasonably practicable;

• ensure regular cleaning of hardstandings using wet sweeping methods;

• not allow dry sweeping of large areas;

• provide and ensure the use of wheel-wash facilities near the site exit wherever thereis a potential for carrying dust or mud off the site;

• fit wheel-washes with rumble grids to dislodge accumulated dust and mud prior toleaving the site wherever there is a potential for carrying dust or mud off the site andwhere reasonably practicable;

• ensure there is an area of hard surfaced road between the wheel wash facility andthe site exit, wherever site size and layout permits;

• install hard surfaced long term haul routes, which are regularly damped down withfixed or mobile sprinkler systems and regularly cleaned;

• inspect haul routes for integrity and instigate necessary repairs to the surface as soonas reasonably practicable;

• record all inspections of haul routes and any subsequent action in a site log bookwhich may be in hard or electronic format;

• ensure that un-surfaced haul routes and work areas are regularly damped down indry conditions;

• routinely clean public roads and access routes using wet sweeping methods;

• ensure vehicles working on-site have exhausts positioned such that the risk of re-suspension of ground dust is minimised (exhausts should preferably point upwards),where reasonably practicable;

• impose and signpost maximum speed limits of 8 kph on un-surfaced haul routes andwork areas and 16 kph on surfaced haul routes and work areas (if long haul routesare required these speeds may be increased with suitable additional controlmeasures provided);

• ensure all vehicles carrying loose or potentially dusty material to or from the site arefully sheeted;


• ensure bulk cement and other fine powder materials are delivered in enclosedtankers and stored in silos with suitable emission control systems to prevent escapeof material and overfilling during delivery;

• mix large quantities of cement, bentonite, grouts and other similar materials indesignated areas which will be enclosed or shielded, as far as reasonably practicable;

• store materials with the potential to produce dust away from site boundaries wherepossible;

• ensure sand and other aggregates are stored in bunded areas and are not allowed to dry out;

• minimise the amount of excavated material held on-site;

• sheet, seal or damp down unavoidable stockpiles of excavated material held on-site,where required;

• avoid double handling of material wherever reasonably practicable;

• ensure water suppression is used during demolition operations;

• ensure that any crushing or grinding plant used on the site, which falls within thedefinition in Section 3.5 Chapter 3 of the Pollution Prevention and Control (Englandand Wales) Regulations SI 2000/1973, has an appropriate permit issued and ismaintained according to the procedures set out in the Pollution, Prevention andControl Act 1999;

• ensure that any plant, identified above, is operated in accordance with the conditionsset out in the permit and a copy of the permit is held on-site;

• use enclosed rubble chutes and conveyors where reasonably practicable or usewater to suppress dust emissions from such equipment;

• always use enclosed conveyors where crossing roads, other public areas andproperty which is not in the ownership or control of the nominated undertaker;

• sheet or otherwise enclose loaded bins and skips;

• minimise drop heights from conveyors, loading shovels, hoppers and other loading orhandling equipment and use fine water sprays on such equipment whereverappropriate;

• seal or re-vegetate completed earthworks as soon as reasonably practicable aftercompletion;

• use design/prefabrication to reduce the need for grinding, sawing and cutting on sitewherever reasonably practicable;

• only use cutting, grinding or sawing equipment fitted or in conjunction with suitabledust suppression techniques such as water sprays or local extraction;

• carry out site inspections regularly to monitor compliance with dust controlprocedures set out above and record the results of the inspections, including nil returns, in the log book detailed;

• increase the frequency of site inspections when activities with a high potential to produce dust are being carried out and during prolonged dry or windy conditions; and

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• record any exceptional incidents causing dust episodes on or off the site and theaction taken to resolve the situation in the log book detailed in above.

Enhanced Dust Control Procedures on Sites with an Medium or High Risk of Dust Emissions (Tier 2)

4.2.3 Where a site has been identified as having a medium or high risk of emissions of dust due to the proximity of receptors, the type of activity on-site or the duration ofoperations, a higher standard of dust control will be required. In these cases, theminimum dust control procedures set out above will be used and the additionalmeasures detailed below will also be adopted as appropriate. Alternatives may beproposed to suit specific circumstance providing the resulting control is at least aseffective as that arrived at using the specified measures.

4.2.4 The enhanced dust control procedures, Tier 2, will include, as appropriate, site controls to:

• strip insides of buildings, as far as reasonably practicable, before demolition;

• bag and remove biological debris (such as birdnests and droppings) or damp downsuch material prior to demolition;

• wherever reasonably practicable, retain walls and windows while the rest of thebuilding is demolished to provide a screen against dust;

• screen buildings, where dust producing activities are taking place, with debrisscreens or sheeting;

• avoid carrying out earthworks during dry weather if possible or provide and ensureappropriate use of water sprays to control dust;

• seed or seal medium or long term excavated material and soil stockpiles;

• ensure slopes on stockpiles are no steeper than the natural angle of repose of thematerial and maintain a smooth profile;

• ensure equipment is readily available on-site to clean any spillages and clean upspillages as soon as possible after the event using wet cleaning methods;

• ensure mixing of cement, bentonite, grout and other similar materials takes place inenclosed areas remote from site boundaries and potential receptors;

• where appropriate use increased hoarding height to protect receptors; and

• consider full enclosure of sites or specific operations where there is a high potentialfor dust production and the site is active for an extensive period.

Advanced Dust Control Procedures on Sites with a High Risk of Dust Emissions(Tier 3)

4.2.5 Where a site has been identified as having a high risk of dust emissions due to theproximity of receptors, the type of activity on site or the duration of operations, thehighest standard of dust control reasonably achievable will be adopted. In these casesall the techniques set out above will be employed and will include additional measuresto control the high risk. This may include having personnel on-site to monitor and


manage dust emissions or techniques such as total enclosure of certain operations toprotect vulnerable receptors. The measures will be proportionate to the risk and will be site specific.

4.3 Asbestos

4.3.1 A management system will be established to ensure that no person at work or memberof the public is exposed to risk to their health from release of asbestos during alterationand demolition works and excavation work. This system will ensure compliance with theControl of Asbestos at Work Regulations 2002 (SI/2002/2675) and associatedApproved Codes of Practice, and will provide for inspection, survey sampling andanalysis in accordance with HSE guidance MDHS100 ‘Surveying, sampling andassessment of asbestos-containing materials’.

4.3.2 Measures for managing asbestos in alteration, demolition and excavation works will include:

• employing competent contractors to carry out alteration and demolition works;

• contractors implementing a procedure for dealing with potentially suspect materialsexposed requiring sampling and analysis by an independent specialist consultant;

• formal exchange of information before start of work, including relevant informationfrom the Asbestos Register to clearly identify the location of asbestos-containingmaterials; and

• method statements for any works in the vicinity of asbestos-containing materials toavoid any disturbance to such materials.

4.3.3 Measures for managing work involving asbestos-containing materials encountered inconstruction will include:

• appointment of a specialist consultant independent of the asbestos treatmentcontractor;

• ensuring any work with asbestos-containing materials is notified to the Health &Safety Executive;

• ensuring any work with asbestos-containing materials is carried out by licensedspecialist asbestos treatment contractors in accordance with Asbestos ( Licensing )Regulations 1983 ( SI 1983/1649 ) as amended in 1998 ( SI 1998/3233);

• requiring method statement defining detailed control measures to be produced bythe specialist asbestos treatment contractor and approved by the independentspecialist consultant;

• air sample monitoring by the independent specialist consultant of work to ensurerequired air quality standards are achieved; and

• disposal of asbestos-containing materials to licensed waste sites in accordance withSpecial Wastes Regulations 1996 (SI 1976/972).

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5 Water Resources

5.1 Procedures

Assessment and Planning

5.1.1 The nominated undertaker or any contractor will undertake the works and implementworking methods which will be developed to protect surface and groundwater frompollution and other adverse impacts including change to flow volume, water levels andquality. This will be completed in accordance with relevant legislative requirements andaccepted industry practice. The nominated undertaker will prepare a strategy forhandling water resources issues which will be agreed with the Environment Agency (EA)as part of the construction planning process.

5.1.2 Water Management Plans will be produced for each of the construction sites and willtake account of the guidance contained within the relevant Pollution Prevention Guides(PPG) issued by the EA and other Construction Industry Research and InformationAssociation (CIRIA) documents. Specific receptors in the water environment will belisted in the plans. Where appropriate, integrated aquatic ecology and water qualityplans will be developed.

Site Drainage

5.1.3 Site drainage, including surface runoff and dewatering effluents, will be discharged tosewers where possible, after any required treatment, and relevant permissions will beobtained from the statutory undertaker. Discharge to watercourses will only bepermitted where discharge consent or other relevant approval has been obtained.

5.1.4 Site drainage will meet the effluent standards required by the sewerage undertaker orEnvironment Agency (EA) as appropriate, and holding or settling tanks, separators andother measures will be provided as may be required.

5.1.5 The relevant sections of BS6031: Code of Practice for Earthworks for the generalcontrol of site drainage will be followed.

5.2 Protection of Watercourses

5.2.1 Approval will be obtained in advance for all crossings of, diversions to, and work withinstatutory buffer zones for watercourses from the EA or other appropriate body.

5.2.2 Protection measures for works in or adjacent to watercourses will be provided inaccordance with appropriate requirements.

5.2.3 Watercourses, including land and/or road drainage, within the construction sites will bemaintained to provide effective working conditions at all times.


5.2.4 All reasonably practicable measures will be taken to prevent the deposition of silt orother material in, and the pollution by sediment of, any existing watercourse, canal,lake, reservoir, borehole, aquifer or catchment area, arising from work operations. The measures will accord with the principles set out in industry guidelines including theEA’s note ‘PPG05: Works in near or liable to affect water courses’ and CIRIA’s report‘C532: Control of water pollution from construction sites’. Measures may include useand maintenance of temporary lagoons, tanks, bunds and silt fences or silt screens as well as consideration of the type of plant used and the time of the year for working in watercourses.

5.2.5 Other than in the tidal Thames, sediment plumes from dredging in inland waterways,including those under control of British Waterways, will be controlled by measures inaccordance with the principles set out in industry guidelines such as the CIRIA’s Report169 ‘Inland Dredging – guidance on good practice’ and Section 6 of CIRIA’s ReportC547 ‘Scoping the assessment of sediment plumes from dredging’. Contaminateddredged material will be managed as described for other contaminated land materials.

5.3 Control of Pollution of Surface Water

5.3.1 Protection measures to control the risk of pollution to surface water will be adopted andwill include, where appropriate and reasonably practicable:

• Any containers of contaminating substances on site will be leakproof and kept in asafe and secure building or compound from which they cannot leak, spill or be opento vandalism. The containers will be protected by temporary impermeable bunds witha capacity of 110% of the maximum stored volume. Areas for transfer ofcontaminating substances will be similarly protected.

• All refuelling, oiling and greasing will take place above drip trays or on animpermeable surface which provides protection to underground strata andwatercourses and away from drains and watercourses as far as reasonablypracticable. Vehicles will not be left unattended during refuelling.

• Only construction equipment and vehicles free of all oil/fuel leaks will be permitted onsite. Drip trays will be placed below static mechanical plant.

• All wash down of vehicles and equipment will take place in designated areas andwashwater will be prevented from passing untreated into watercourses and willcomply with EA’s PPG13.

• EA note PPG 23 will be followed when carrying out maintenance of structures overwater. As far as reasonably practicable, only biodegradable hydraulic oils will be usedin equipment working in or over watercourses.

• Appropriate measures to be taken to protect erodable earthwork surfaces.

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5.4 Control of Pollution of Groundwater

5.4.1 Protection measures to control the risk of pollution to groundwater will be includedwithin the overall strategy.

5.4.2 Where reasonably practicable and appropriate, the nominated undertaker or anycontractor will avoid using materials in the permanent or temporary works that couldpollute groundwater. This will include special consideration for any use of substancescontained within List I and II of the Groundwater Regulations SI 1998/2746(Groundwater Directive: 80/68/EEC). Materials likely to be in contact with the aquiferduring tunnelling operations will be selected in accordance with appropriate industrypractice.

5.5 Mitigation of Impacts at Abstraction Boreholes

5.5.1 The previous section describes the measures used to minimise the risk of groundwaterpollution. However, at any particular abstraction, there will be a residual risk that thewater quality may become unusable by an abstractor. The following precautionaryactions will be applied, where applicable, to limit and manage the residual risks:

• Routine water quality monitoring will be undertaken at abstraction sources. Theperiod of monitoring and the parameters monitored will be appropriate to the timingand type of work undertaken. The need for intermediate monitoring holes andprocedures for water and contaminant testing during construction and operation willbe discussed with the owners.

• The nominated undertaker or any contractor will arrange any necessary monitoring of water levels in areas where dewatering of the deep aquifer is planned. The rights of existing abstractors will be recognised and consultation will be undertaken on measures to avoid loss or interruption of supply or theprovision of alternative supplies.

5.6 Dewatering

5.6.1 The foregoing provisions will also apply to dewatering, in addition to the following:

• Relevant licenses and consents will be obtained for dewatering wells.

• Records of water pumped will be kept at all major dewatering sites where wells areconstructed in the deep aquifer or where required under the terms of a dischargeconsent.

• Water quality at all major dewatering sites will be monitored weekly for the first fourweeks of pumping and monthly thereafter. Monitoring will comprise a laboratory testof major ions and a field test of temperature and electrical conductivity as well asother parameters required under the conditions of an abstraction or discharge licenceconsent or permit.


5.7 Monitoring and Mitigation of Water Levels in the Shallow Aquifer

5.7.1 Additional site investigation (SI) will take place and some SI boreholes will be convertedto standpipes where significant changes in water levels in the shallow aquifer areexpected as a result of temporary dewatering or construction of major structures whichcut off the shallow aquifer and could cause water levels to rise. Selected water levelswill be monitored for a maximum of 12 months after dewatering or construction of thecut off is completed. The monitoring data will be analysed in relation to data onelevations of nearby basements and existing drains. Additional drainage will be providedas mitigation where necessary.

5.8 Dredging

5.8.1 Dredging in the tidal River Thames will be carried out in accordance with therequirements set out by the Port of London Authority.

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6 Contaminated Land

6.1 Site Assessment and Remedial Practice

6.1.1 The nominated undertaker or any contractor will carry out site assessments,investigations and/or risk assessments wherever construction work is planned in orderto determine the potential for contamination in both soil and groundwater. Thenecessary measures will be agreed with the Environment Agency and Local Authoritiesas part of the construction planning process.

6.1.2 A set of criteria for site investigation will be developed prior to the commencement ofany intrusive works. Where site investigation reveals the presence of contaminated landan appropriate remedial strategy will be developed to identify the most appropriateoption for dealing with the presence of contaminated land. This strategy would includethe following:

• Liaison with the local authority, the Environment Agency and other relevant statutorybodies with a view to addressing their requirements and agreeing control orprotection measures necessary to provide appropriate mitigation. This may involvethe sealing, excavation and disposal of soil or on-site remedial works. The treatmentproposed would be in accordance with the waste hierarchy as set out in Section 7and on-site remedial measures would be the preferred method of treatment.

• An assessment of the composition of the waste soil using appropriate techniques,which could include sampling and laboratory analysis, to determine if the waste isclassifiable as hazardous. The Consolidated European Waste Catalogue (EWC) liststhose wastes that are ‘absolute entries’ (hazardous waste regardless of theirconcentration) and ‘mirror entries’ (hazardous waste only if ‘dangerous substances’are present above threshold concentrations). Contaminated soils are ‘mirror entries’in the EWC. This means that contaminated soils may be classified as eitherhazardous or non-hazardous depending on the concentrations of ‘dangeroussubstances’ in the soil.

• Considering alternatives to landfill disposal as the solution to treating contaminatedsoil. This may include the use of remedial technologies (in-situ and ex-situ) to reducethe quantity of soil requiring disposal, and/or treatment of soils to a standard suchthat they can be re-used at a site or be disposed of as non-hazardous waste. On-siteremedial works will be carried out under the Waste Management LicensingRegulations 1994 (SI 1994/1056).

• Monitoring of excavation works to check for unexpected or unusual materials with acontaminative potential. This material could consist of buried drums, tanks orcontainers, soil, groundwater or liquids with an unusual colour or odour, or otherevidence of contamination. If this type of material is encountered work will bestopped until the material has been properly identified and suitable precautions taken.

• Specific precautions if materials containing asbestos are present or encounteredduring works, as detailed in Section 4.3 and Table 6.2.


• Designation of areas on-site where contaminated materials can be separated fromclean ones and stored in an appropriate environment. Storage of contaminatedmaterials may require specific facilities to prevent contaminants from leaching into theground, nearby watercourses or neighbouring properties.

• Adherence to guidance provided in the EA’s Pollution Prevention Guidance Notes(PPGs) in respect of water pollution in particular PPG01, PPG02, PPG05, PPG06,PPG21 and PPG23 as far as reasonably practicable.

• On completion of any remedial works, recording of the works undertaken to complywith the remedial strategy.

6.2 Remedial Techniques

6.2.1 Potential mitigation measures to deal with contaminated land are set out below in Table6.1 and Table 6.2. An assessment was undertaken and consequently the likelycontaminants which may be encountered are grouped (as set out below) and thecontaminant groupings are linked to remediation measures which are typically used andeffective in mitigating the relevant contaminant.

• Inorganic compounds:

• Metals (eg cadmium, lead, arsenic, mercury, copper, nickel and zinc);

• Cyanides and sulphates; and

• Minerals (eg asbestos).

• Organic Compounds:

• Solid hydrocarbons (eg coke and coal);

• Polychlorinated biphenyls;

• Liquid hydrocarbons (eg solvents, oils and tars, phenols and polyaromatichydrocarbons); and

• Pesticides and herbicides.

• Biological:

• Pathogens eg bacteria, viruses (eg anthrax).

6.2.2 Table 6.1 and Table 6.2 demonstrate that a wide range of remedial techniques areavailable which can mitigate the potential impacts resulting from the abovecontaminants. Given the variety of former uses at significant sites along the Crossrailroute, it is likely that a combination of the techniques listed may be implemented toensure that the potential impacts identified are resolved. With the application of thetypes of mitigation measure set out in Table 6.1 and Table 6.2, the construction ofCrossrail is not expected to give rise to any significant impacts in relation tocontaminated land.

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Table 6.1 Potential Remedial Techniques for the Treatment of Contaminated Land

Key: S: Soil GW: Groundwater OC: Organic Compounds PCBs: Polychlorinated BiphenylsPH: Pesticides Herbicides M: Metals A: Asbestos

Remedial Technique

Description S GW OC PCBs PH M A

PersonalProtectionEquipment (PPE)

Personnel working with contaminatedmaterials should have clothing andequipment appropriate to the tasksinvolved. This may include dust andvapour masks, breathing equipment,overalls, gloves and footwear.

• • • • • • •

EngineeringTechniquesDisposal of soil(1)

Contaminated materials aremechanically excavated and disposedat a suitable licensed landfill. Generallysuitable for all contaminants.

• • • • • •

Cover systems An engineered layer of uncontaminatedmaterial which covers contaminatedground. The layer should preventcontact between contaminants andhumans, animals and plants; controlthe upward migration of contaminantsin water and minimise percolation ofsurface water through the capping layerwhich would facilitate migration.

• • • • •

Vertical barriers A physical wall is constructed aroundthe source of the contamination, whichdisrupts the groundwater flow aroundthe source.

• • • • • • •


1 The Landfill (England and Wales) Regulations 2002 implement the Landfill Directive (Council Directive 1999/31/EC), which aims to prevent, or to

reduce as far as possible, the negative environmental effects of landfill. The implementation of the next phase of these regulations in July 2004

has resulted in over 200 landfill sites around the UK no longer accepting hazardous waste. As a consequence of the closure of landfill sites to

hazardous waste and achieving the overall aims of sustainable development encouraged by the regulators, process-based remedial technologies

for land and groundwater treatment will become more common place in contaminated land projects and time frames for undertaking this type of

remedial work will need to be factored into any advanced works where necessary.


Remedial Technique

Description S GW OC PCB’s PH M A

In situ TreatmentsSoil vapourextraction and bioventing

Air is moved via wells in the unsaturatedzone to volatilise contaminants orbiodegrade contaminants. Thevolatilisation removes the contaminantsfrom the soil and contaminants undergosecondary treatment (usually throughcarbon vessels) prior to discharge.

Bioventing supplies oxygen andsometimes nutrients into theunsaturated zone which stimulates thebiodegradation of contaminants in situ.

• •

Air Spargingand bio-sparging

This technology, which is also knownas ‘in situ air stripping’ and ‘in situvolatilisation,’ involves the injection ofcontaminant-free air into thesubsurface saturated zone enablingorganic contaminants to transfer froma dissolved state to a vapour phase.The air is then vented through theunsaturated zone.

Bio-sparging technology usesindigenous micro-organisms todegrade organic contaminants. Bio-sparging uses similar techniques to airsparging, but with much reduced airinjection volumes and flow rates. Theintroduced air enhancesbiodegradation in and above the watertable. Nutrients can also be injectedinto the system to enhance microbialactivity. Suitable for organiccontaminants.

• • • • • •

In situ flushing A flushing solution is injected into soilsabove the water table via wells tomobilise contaminants into the liquidphase (an aqueous solution). This isthen pumped to the surface viaextraction wells and treated prior tobeing returned to the aquifer, reusedin the flushing solution or beingdischarged.

• •

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Remedial Technique


In situ Treatments

Pump and treat

Pump and Treat is an establishedand proven technology wherebycontaminated groundwater ispumped to the surface and treatedex situ, before it is either returned tothe aquifer or discharged under alicence to a surface water body orsewer. Once the groundwater is atthe surface, the concentration ofcontaminants can be readilyreduced to a low level usingestablished technologies (eg airstripping, chemical oxidation orbiodegradation).

• • • •

Permeablereactivebarriers

A permeable reactive barrier acts asan in situ treatment wall which treatsgroundwater as it passes through.The most commonly used reactormaterials are granular iron andactivated carbon.

• •

Monitorednaturalattenuation

Natural attenuation describes arange of physical and biologicalprocesses which unaided bydeliberate human intervention,reduce the concentration, toxicity, ormobility of contaminants. Long-termmonitoring is generally required toassess the effectiveness of thescheme.

• • • •

Ex situ Treatments

Ex situbioremediation

Ex Situ bio-remediation usesmicrobiological processes todegrade contaminants.Contaminated soils are excavated,screened and placed into treatmentbeds where nutrients and otheradditives, (eg certain types of fungior bacteria), are blended into the soilto produce a uniform mixture. Thetemperature and moisture contentof the soils controlled. The aim is forsoils to be degraded to carbondioxide, water and inorganic salts.

• •



Notes:•Indicates which technique is potentially suitable for a particular type of contaminant.the suitability of the various techniques for a particular contaminant is dependent upon a variety of factors such as soil type, groundwater conditions, chemical parameters of the contaminant and temperature.Some techniques are suitable for soil, others for groundwater and some for both. Please checkthe appropriate column.

Remedial Technique


Ex situ Treatments

Soil Washing Soil washing is a mechanicalprocess that uses liquids, usuallywater, to remove contaminants fromsoils. These contaminants usuallyadhere to the surfaces of the silt orclay particles rather than to thecoarser sand or gravel particles.Therefore, the purpose of soilwashing is to first separate the finesilt and clay particles from thecoarser sand and gravel particlesbefore passing the remainingmaterial through aqueousseparation processes whichseparate contaminated materialfrom uncontaminated material.

• • • • • •

Solidification/Stabilisation

Solidification/stabilisation usesmixes contaminated soil withchemical agents to enhance thestructure of the matrix and reduceits permeability. This reduces thepotential for contaminants tomigrate through groundwater.

• • • •

Thermaltreatment

Thermal treatment uses heat toremove or destroy contaminants.Excavated soil is fed after pre-treatment (eg shifting of oversizedmaterials) to a thermal processor.Gases which are generated passthrough a cleaning plant prior to emission.

• • • •

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Table 6.2 Potential Remedial Techniques for the Treatment of Additional Contamination Sources

Potential Sources of Contamination Description of Remedial Treatment Method

Underground and above-ground fuelstorage tanks

Fuel storage tanks and associated features (eg dispensingpumps, underground fuel links and interceptors) will beemptied and removed. Surrounding soils or groundwaterwhich have been impacted by the tank contents will beappropriately treated by methods described above.

Asbestos containing materials Where asbestos is identified in soil, appropriate handlingand disposal will be required. Asbestos contaminated soilhas resulted from mixing soil with demolition rubble, poorhousekeeping at industrial sites and poor waste disposalpractices in the past. Any materials containing asbestosthat could become airborne should, where possible, bekept damp.

Any material containing asbestos should be disposed of incovered skips or should be double bagged. In either case,the material must be clearly labelled. Soil that containsmore than 0.1% asbestos is considered Special Waste.

(Also see Section 4.3 of this Appendix)

Elevated concentrations of landfill gas (eg methane, carbon dioxide, hydrogen sulphide)

Appropriate capping and gas management systems.


7 Waste Management and Recycling

7.1 General

7.1.1 The management of excavated materials and waste will be in accordance with thewaste hierarchy:

• minimise generation of excavated materials and wastes;

• re-use and recycle excavated materials and waste within the Crossrail project;

• re-use and recycle excavated materials and waste through environmentally beneficialuse at registered exempt sites; and

• dispose of surplus excavated materials and waste at licensed landfill sites.

7.1.2 The requirements of the waste hierarchy will be enforced and the duty of care will beplaced on all parties to take responsibility for protecting the interests and safety ofothers from the potential effects of handling, storing, transporting and depositing ofexcavated materials and wastes.


Site Waste Management Plan

7.2.1 Site Waste Management Plans (SWMPs) will be produced in accordance withappropriate industry practice.

7.2.2 SWMPs will be produced in accordance with the Site Waste Management Plans –Guidance for Construction Contractors and Clients - Voluntary Code of Practice(Department of Trade & Industry, July 2004), which details a process which will befollowed.

Duty of Care

7.2.3 The nominated undertaker and any contractor will comply with the duty of care toprotect the interests and safety of others from the potential effects of handling, storing,transporting and depositing of excavated materials and demolition/construction wastesarising under the project.

7.2.4 The guidance set out in Waste Management – The Duty of Care, Code of Practice(HMSO, March 1996) will be followed in addition to the obligations under the duty ofcare regulations.

7.2.5 The SWMPs will include detailed procedures for compliance with the requirements forwaste transfer notes in accordance with the Environmental Protection (Duty of Care)Regulations 1991 (SI 1991/2839) and arrangements for auditing the actions of otherparties in the waste handling chain. A sample waste transfer note document, togetherwith details of the administrative arrangements for record keeping, will be included inthe SWMPs.

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7.2.6 The arrangements for handling hazardous wastes will be followed in the context of dutyof care and the specific consignment note procedures applicable under the SpecialWaste Regulations 1996 (SI 1996/972) or any succeeding relevant legislation.

Specific Provisions/Measures Available

7.2.7 Specific provisions/measures available for the handling of excavated materials anddemolition/construction wastes will be reflected in the SWMPs and in the contractualrequirements.


8 Ecology and Nature Conservation

8.1 General Provisions

8.1.1 Mitigation measures set out in this section will be applied to sites individually inaccordance with the following principles:

• prior to work commencing, sites will be checked for protected species by qualifiedpersons, through site inspection or survey as appropriate;

• where protected species are identified (prior to or during works) the acceptability of mitigation measures set out in this section will be reconfirmed with English Nature to ensure compliance with potentially changing future legislation and views on best practice;

• construction activities will be confined to the minimum areas reasonably required forthe construction of the works, having regard to the demands of the project;

• within temporary work area boundaries, operations will use existing hard standing or amenity grassland of low conservation value wherever possible (including site access);

• control measures will be adopted in the event that invasive alien species are found toensure that they will not be inadvertently dispersed by works;

• procedures will be implemented to ensure that species specified on Schedule 9 ofthe Wildlife and Countryside Act 1981, as amended, are not knowingly introduced orcaused to grow in the wild;

• removal of woodland, isolated trees, scrub and other vegetation suitable for nestingbirds will preferentially take place outside the breeding bird season (approximately 1st

March to 31st July); or else vegetation will be checked for nesting birds by qualifiedpersons immediately prior to removal; and if nests in use are found, works will bepostponed or modified to avoid disturbing nests, nesting birds or their young (sincethese are offences under The Wildlife and Countryside 1981, as amended);

• after construction, habitats or ecological features will be reinstated, or for preferenceallowed to recolonise naturally, so that they recover to their pre-construction condition(so far as possible);

• landscape planting (other than ornamental and specimen tree planting) will forpreference be undertaken using native species typical of the area, where possibleobtained from local sources;

• in wetland habitats and watercourses adjacent to the works, impacts will be avoidedby appropriate design of site drainage and by use of construction techniques tomaintain existing drainage patterns along sensitive sections of the route;

• topsoil and subsoil will be stripped and stored separately and reinstated accordingly;this will be done as soon as reasonably practicable to minimise adverse impacts tothe soil structure;

• the reinstatement potential of seed banks in stripped topsoil will be optimised byreplacing soil in areas of works as close as reasonably practicable to its location oforigin (particularly important for areas of nature conservation interest);

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• appropriate construction management practices will be adopted on-site to minimisethe risk of indirect impacts to adjacent habitat (for example, direct incursions,pollution, draining of adjacent wet habitats); and

• where appropriate, construction activities will be screened to protect the wildlifeinterest and the amenity value of nature conservation sites that are adjacent to works.

8.2 Mitigation Specific to Bats

Introduction

8.2.1 Prior to construction, all buildings, structures and trees with any appreciable degree ofbat-roost potential will be re-appraised, and pre-construction surveys will be carried outwherever necessary.

8.2.2 Crossrail surveys have not found roosting bats in any location with bat-roost potential.Mitigation set out below therefore provides detail of the precautionary procedures to beadopted in the demolition of buildings and structures, and the felling of trees, where theinitial suggestion of bat-roost potential has been discounted by appraisal or survey, butas a matter of principal (in this or any other project) a slight risk must remain.

8.2.3 If a bat roost were to be found, then works could only proceed under Defra licence. Themitigation measures that would be adopted – and these would be set out in the licenceapplication for approval (as a requirement for Defra licensing) – are specified in detail inthe English Nature document Bat Mitigation Guidelines dated January 2004. They maybe summarised for the least unlikely scenarios as follows:

• night roosts in trees – exclusion, felling as specified below, provision of bat boxesaccording to species and summer/non-breeding specifications in Table 8.3 in BatMitigation Guidelines;

• small maternity roosts of common species in trees – mitigation works within seasonalconstraints set out in Table 8.1 in Bat Mitigation Guidelines, felling as specified below,provision of bat boxes according to species and summer/maternity specifications inTable 8.3 in Bat Mitigation Guidelines;

• feeding perches and night roosts in structures and buildings – exclusion, demolitionas specified below, provision of bat boxes as above or incorporation of new roosts(as specified in Sections 8.5 and 8.6 in Bat Mitigation Guidelines) into replacementbuildings or structures that are part of the scheme (eg vent shafts);

• small maternity roosts of common species in structures and buildings – mitigationworks within seasonal constraints set out in Table 8.1 in Bat Mitigation Guidelines,demolition as specified below, provision of bat boxes as above, or incorporation ofnew roosts (as specified in Sections 8.5 and 8.6 in Bat Mitigation Guidelines) intoreplacement buildings or structures that are part of the scheme;

• hibernation sites – mitigation works within seasonal constraints set out in Table 8.1 inBat Mitigation Guidelines, demolition or felling as specified below, incorporation ofnew roosts (as specified in Sections 8.5 and 8.6 in Bat Mitigation Guidelines) intoreplacement buildings or structures that are part of the scheme.


General Procedures for All Works

8.2.4 The following procedure will be applied to all locations having some appreciable bat-roost potential where bats are not believed to be present and Defra licensing is not required.

• All site workers will be made aware of the possibilities of finding bats and theprocedure to follow should they be found.

• If at any point during the works a bat or bats are discovered:

• contractors will stop work immediately and telephone a bat worker or anominated ecological professional qualified to deal with bats. Telephone numbersof such will be held on site.

• further action will only be taken following advice given by English Nature. This mayinclude removal of bats, but only where direct written or verbal permission isgained from English Nature and Defra if English Nature advise that a licence isnecessary.

• only when English Nature, and Defra (if the work is licensable), is satisfied that therisk to bats is acceptably controlled should works recommence.

• Where appropriate, works will be ceased until a Defra licence has been obtained.

• If a bat(s) is found in any crack or crevice that is being demolished, works will stopimmediately. If the bat(s) does not voluntarily fly out, then the aperture will be carefullycovered over to protect the bat(s) from the elements and leaving a small gap for thebat to escape voluntarily. Further advice should then be sought from a nominatedecological professional or English Nature. Any covering will be free from grease orother contaminants, and will not be a fibreglass-based material.

• If any bats fall out of structures or are injured, they will be gently placed in a secureventilated box, (eg a cardboard box), by the contractor and left in a cool dark place.The licence holder or an ecological professional qualified to deal with bats will becontacted immediately and their advice sought.

Specific Procedures

Overview

8.2.5 In addition to those general procedures detailed above, the following procedures will befollowed where appropriate.

Mitigation Particular to Buildings

8.2.6 The following measures will be applied:

• Where buildings have soffit boxes, these will be removed carefully by hand prior todemolition. If at any point during the works bat(s) are discovered, contractors will stopwork immediately and the licence holder or an ecological professional qualified todeal with bats will be contacted for advice. If bats are found a Defra licenceapplication will be required.

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• Where buildings have barge boards, these will be removed carefully by hand prior to demolition. If at any point during the works bats are discovered, contractors will stop work immediately and contact the licence holder or an ecologicalprofessional qualified to deal with bats. If bats are found a Defra licence applicationwill be required.

Removal of Ridge Tiles and Roof Tiles

8.2.7 In some cases it will be necessary to remove the ridge and roof tiles by hand this willneed to be carried out prior to demolition.

• All ridge tiles and the entire top three rows of tiles on either side of the roof will needto be removed carefully and the building will be left over a frost-free night to allow any bats present in the structure to leave.

• Where dormer windows are present all tiles will be carefully hand removed around the structure.

• Removal will not commence if a frost is anticipated.

Removal of Roof Tops

8.2.8 Where it has been identified as necessary to remove the roof by hand this will need tobe carried out prior to demolition.

• All roof cladding layers and any window structures will need to be removedseparately and carefully, taking care to ensure that damage does not occur to roofand wall load-bearing joints as bats may be roosting in or behind these features.

• The building will then be left over a frost-free night to allow any bats present in thestructure to leave.

• Removal will not commence if a frost is anticipated.

Mitigation Particular to Trees

8.2.9 The following measures will be applied:

• Where it has not been possible to discount the presence of bats in a tree, specificfelling procedures are required to ensure bats or their roosts are not disturbed ordamaged. A qualified and experienced arboriculturist will be present on site tosupervise felling of all trees requiring specific procedures.

• Where possible and appropriate for the tree, works will be undertaken duringSeptember and October or March and April, ensuring that nesting birds are notdisturbed by the operations.

• Works will be carried out during frost-free periods to prevent potential disturbance tohibernating bats.

• Site workers will be made aware of and follow the advice given in Bats and Trees – AGuide to the Management of Trees published by the Bat Conservation Trust. A keypart of this advice describes appropriate working practice for felling trees with bat-roost potential.


• Trees identified as having bat-roost potential will be felled in sections and each partlowered to the ground gently, ensuring that they do not fall. All cut material will be lefton site for 72 hours before disposal to allow any bats present to leave.

• Where specific holes or cracks have been identified as suitable for bats, cuts will bemade no closer than 1 m to these holes. If recesses extend further than 0.9 m, thearboriculturist will decide on the height of the cut to be made to prevent potentialdamage or destruction of a bat roost.

• When carrying out the works ensure that the following contact numbers are availableon site:

• the licence holder or an ecological professional qualified to deal with bats; and

• the local office of English Nature.

• Holes, cracks and hollows, which may not have been identified from ladders, will bechecked. If any holes, cracks and hollows are identified work will stop and the licenceholder or an ecological professional qualified to deal with bats will be contacted.

• A search will be made for bats in cracks and splits that may be held open by theweight of the branch before removing large limbs. If any bats are found, works will bestopped and a licence holder or an ecological professional qualified to deal with batscontacted immediately.

• Where Ivy is present, this will be cleared first and then trunk and branches assessedfor holes prior to undertaking any work. Ivy will be left on site for 72 hours prior todisposal to allow any concealed bats to disperse. If any holes, cracks and hollows inthe tree are identified behind the Ivy, work will stop and the licence holder or anecological professional qualified to deal with bats will be contacted.

• Dead and dying wood is extremely important to bats; it will be retained where thiscan be done safely, preferably standing, otherwise it will be left on site for 72 hoursbefore disposal to allow any bats to disperse.

8.3 Mitigation Specific to Reptiles

Overview

8.3.1 Where populations of reptiles have been identified, full mitigation will involvetranslocation of individuals to a suitable habitat in a receptor site. Criteria for selection ofreceptor sites are as follows:

• a suitable existing, enhanced or created site, offering basking, foraging andhibernation habitat suitable for the species involved;

• a site preferably at least as large that to be lost;

• a site preferably without an existing reptile population; and

• a site with capacity to support the translocated population without harm to anyexisting population that might be present.

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8.3.2 Where works will affect a large proportion of an area of habitat used by reptiles,translocation will be to a remote site. Where work areas represent a small fraction of anarea of habitat, ie less than 10%, in situ relocation will be the preferred, whereverpossible to retained areas of similar habitat close by.

8.3.3 In either case, work areas will be isolated with reptile-proof fencing, refugia will be laidout inside the fences (usually pieces of tin or roofing-felt under which reptiles shelter) atdensities recommended in English Nature guidelines, reptiles will be captured by hand(from beneath the refugia), and captured individuals will be translocated. Additionalsafety precautions are necessary for adders, but the procedure is the same. For largetranslocations, including all those to remote sites, the capture process will be deemedcomplete when no reptiles are captured on seven suitable successive days after at least30 suitable-weather-days of trapping have been undertaken.

General Procedures

8.3.4 In cases where habitat suitable for reptiles has been identified but risks to reptiles areconsidered sufficiently limited that translocation is not necessary, the followingprocedures will be followed. Operations will be done in such a way as to ensure that noindividuals are injured or killed to reduce the chances of committing an offence underthe Wildlife and Countryside Act 1981 (as amended).

8.3.5 The timing of these works will coincide with periods when reptiles are not in hibernation.The individuals then spend several hours of the day basking to increase their bodytemperature and so may be visible to the human eye. They will use edges of scrub orlog piles generally in the morning.

8.3.6 Before work commences a walkover of the site by a qualified person will be undertakento check there are no reptiles. The following are actions which will be undertaken whenworks commence:

• Whilst working in areas of rough grassland, and scrub, all site workers will be madeaware of the possibility that some reptiles may be present.

• Contractors will be briefed to watch for reptiles, and to remove them to safetywhenever they are encountered.

• If more than 10 individuals are seen at any one location, works will be stopped untilsuitable advice has been sought.

• Any plant and machinery will be restricted to the reasonably practicable minimumworking area.

• If topsoil is to be removed then the machine operator and/or standing lookout willwatch for reptiles which are beneath the surface or in disturbed earth, and removethem to safety.

• Where possible works will avoid suitable basking or foraging habitat, (eg log piles,rubble piles, tall vegetation and scrub). If this cannot be avoided then the habitat willbe carefully searched and taken apart by hand where appropriate, (eg rubble piles),and any reptiles moved to safety.


8.4 Mitigation Specific to Great Crested Newts

8.4.1 Where ponds supporting great crested newts have been identified within 500 m of aworksite or work area, mitigation will be designed and licences will be obtained asappropriate. Where appropriate mitigation is likely to include:

• fencing of works areas with herptile proof fencing;

• removal of all great crested newts from the affected areas, prior to workscommencing. This would be undertaken using standard techniques, (eg drift fencing,pit fall trapping, use of refugia and hand searching). It is not considered likely that anyponds that support great crested newts will be directly affected. However if this is thecase the use of bottle trapping and hand netting will be used;

• release of captured individuals at the breeding pond, where possible, or where this isnot possible, release in appropriate existing, enhanced or created terrestrial habitatwithin range of the breeding pond; and

• consideration of the potential impacts of habitat loss and implementation ofappropriate compensation requirements such as habitat creation or enhancement.

8.4.2 Where all available survey methods have not proved conclusively whether a pond with500 m of a work area supports great crested newts, the following methodology will beemployed. It will only be used as a last resort when all survey methods have failed:

• all vegetation will be cut to 0.15 m above ground level;

• all potential refugia (stones, rubble and other detritus) will be removed by hand, with operatives searching for great crested newts at all times; and

• topsoil or surface layer stripping will be carried out a banksman or other operativewatching for great crested newts; and

• if at any time during this process great crested newts are discovered, works willimmediately stop until advice had been sought and where appropriate a Defra licence obtained.

8.4.3 These measures do not need to address mitigation for ponds within work areas thatsupport great crested newts, as no such ponds will be lost as a result of the scheme.

8.5 Mitigation Specific to Water Voles

Overview

8.5.1 Mitigation will apply the principles detailed below, taking into account changes in legalrequirements and best practice at the time of construction. The mitigation strategy willdepend on the exact nature of the impact, taking into account:

• whether the proposals involve temporary or permanent impacts; and

• the length of habitat affected and what proportion of the available habitat this represents.

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8.5.2 In cases where there will be short-term temporary impacts to a small proportion of available habitat, it may be appropriate to temporarily exclude or discourage animals from affected areas, re-instating habitat and allowing them to return after works are complete.

8.5.3 In cases where there will be permanent loss of a small proportion of available habitat,habitat will be enhanced or created to compensate for that which is lost. Water volesmay either be taken into captivity until works are completed or translocated directly into the treated areas.

8.5.4 In cases where there will be permanent destruction of a large proportion of an area ofhabitat, extensive habitat creation will be required at an appropriate location as close aspossible to the existing population.

Off-site Relocation

8.5.5 Where it is necessary to transfer water voles to alternative receptor habitat, sites willonly be chosen which can fulfil the following criteria:

• the site contains at least as much suitable habitat as the affected site;

• the site does not have a current Water Vole population; and

• the site is will be able to support the population for the foreseeable future.

8.5.6 The following desirable criteria will be met where possible:

• the receptor site is as close as possible to the affected site;

• the reasons why the receptor site does not support water voles can be explained,and if possible alleviated, ie the site can be made suitable for water voles.

Long Term Holding

8.5.7 Holding water voles will be carried out according to the following principles:

• where possible trapping of water voles will be carried out in late summer or earlyautumn, but will not continue after 1st November;

• where possible re-release will be carried out in spring (1st April to 1st June);

• within these seasonal constraints water voles will be held for as short a period aspossible; and

• individuals will either be bred or held in isolation depending on the season and lengthof time they will be held.

Exclusion from Habitat Creation Areas

8.5.8 Exterior grade plywood fencing, extending 1 m above ground and 0.2 m below ground,will be used where it is necessary to exclude water voles from particular areas.


8.6 Protection of Trees

8.6.1 Any essential remedial or protective work to trees adjacent to construction activity willbe carried out by suitably trained or qualified personnel using recognised methods inaccordance with BS 5837 ‘Guide for Trees in Relation to Construction’.

8.6.2 Appropriate protection measures for tree protection will be implemented as specified inBS 5837: 1991. This will include protective fencing and prohibition of storing ordumping materials within the protected area.

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9 Archaeology and Heritage

9.1 Procedures

9.1.1 It is expected that the following documents and procedures will be approved to controlarchaeological and heritage issues:

• a generic project-wide Archaeological Written Scheme of Investigation (WSI); and

• procedures to control alteration to or demolition of listed buildings.

9.1.2 Archaeological and heritage procedures will be produced for each site. The moredetailed site-specific Written Scheme of Investigation will be based on the principles andmethodologies laid down in the generic Written Scheme of Investigation.


9.2.1 Mitigation measures that address archaeology and heritage issues will be considered ona site by site basis, incorporating the requirements of the WSI and agreements onheritage issues and following these general principles, as appropriate:

• An agreed mitigation programme for cultural heritage related work will beimplemented prior to the commencement of construction works with additionalmonitoring during construction where appropriate.

• Suitable precautions will be taken to avoid any unplanned impacts on identifiedcultural heritage resources.

• Demolition and alteration of listing buildings will be undertaken in line with the agreed procedures.

• The design of replacement buildings within conservation areas will be undertaken,taking the existing building as a baseline.

• Procedures will be established and agreed for the dismantling and re-erection ofcertain listed buildings and other historical structures.

• Procedures will be established and agreed for the removal and storage for potentiallater re-use of fittings from certain listed buildings and other historical structures.

• Where necessary, suitable screening and other protective measures will be erectedaround archaeological mitigation works and around historic buildings within andadjacent to works areas.

• Where archaeological remains are encountered unexpectedly during works, anappropriate programme of mitigation will be agreed with stakeholders andimplemented.

• Procedures will be established and agreed for the management and maintenance of historic buildings that may left empty during construction, until such times as thesebuildings are subsequently occupied or disposed of.

• Procedures will be established and agreed for the emergency repair of damage to historic buildings.


• All temporary work areas including site accesses will be constructed with regard to minimising ground reduction. Where possible such work areas will be establishedthrough the raising of ground levels.

• Security procedures will be established and agreed to prevent unauthorised accessto archaeological sites and historic buildings and the damage or theft of culturalheritage resources, including the use of metal detectors.

• Procedures will be established and agreed to be followed in the event of thediscovery of human remains.

• Procedures will be established and followed in the event of the discovery of artefactsthat fall within the criteria identified in the Treasure Act 1996. These procedures will be in line with the Treasure Act Code of Conduct 1997.

• An appropriate level of analysis and publication of the results of archaeologicalinvestigations will be agreed and implemented in a format suitable for publicdissemination.

• A clear policy will be agreed and implemented regarding the deposition at appropriatepublic archives of artefacts, records, and data recovered from archaeologicalinvestigations.

• Condition surveys will be undertaken to define appropriate vibration limits for cultural heritage resources that may be potentially affected by vibration fromconstruction works.

• Where cultural heritage resources are very close to worksites, or attached tobuildings or structures that form parts of worksites, detailed assessment will beundertaken prior to commencement of works to inform the selection of specific items of plant and working methods.

• For cultural heritage resources that are attached or contiguous to buildings that areproposed for demolition, the attached buildings will be unattached, wherepracticable, using non-vibratory techniques, such as diamond sawing, beforedemolition commences.

• Where necessary, appropriate vibration monitoring regimes will be adopted duringdemolition or other major activities. This would, to provide full safeguarding, in theworst case, allow cessation of works should vibration levels exceed relevant limits.

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10 Settlement


General

10.1.1 The nominated undertaker will undertake settlement assessments for buildings withinthe zone potentially affected by settlement and will use established methods to assessthe risk of damage to buildings and the need for mitigation.

10.1.2 All sub-surface excavations including boxes, shafts and tunnelling give rise to groundmovement. These movements manifest themselves, in particular, as settlement. Thissettlement has the potential to give rise to damage to buildings and other infrastructureincluding utilities. This can range from small internal cracks in plaster through to effectson the structure, although in most cases there is no discernible effect. The applicationof the appropriate measures to control and mitigate settlement can reduce this impactto acceptable levels.

10.1.3 The potential implications of settlement have been considered as part of the designprocess. Mitigation measures will be taken during construction to protect buildings fromsettlement that might otherwise affect their structural integrity. The mitigation measurescan be categorised as follows:

• At-source measures. These include all actions taken from within the tunnel, shaft orbox excavation during its construction to reduce the magnitude of groundmovements generated at source (for example, the tunnelling method).

• Ground treatment measures. These comprise methods of reducing or modifying theground movements generated by tunnelling/box excavation by improving or changingthe engineering response of the ground. The categories of ground treatment are:compensation grouting, which involves injecting grout into the ground above thetunnel to compensate for the ground loss at the tunnel face; installing an isolating wall(e.g. of reinforced concrete) in the ground between the tunnel/box excavation and apotentially affected building or structure; permeation or jet grouting which involves thecreation of stiffer ground to reduce settlement; and control of ground water to avoidchanges which could potentially cause ground movement.

• Structural measures. These methods reduce the impact of ground movements byincreasing the capacity of a building or structure to resist, modify or accommodatethose movements. Typical measures would include underpinning or jacking.Underpinning involves the introduction of a new strengthened foundation system to abuilding or structure potentially affected by settlement. Jacking is a techniquewhereby a system is introduced between the structure and its existing foundations tocompensate for the settlement.

10.1.4 The above mitigation measures are tried and tested and have proved effective inmitigating potential settlement effects on other major projects involving a similar scaleand complexity of tunnelling and excavation.


10.1.5 The nominated undertaker and his contractors will take a number of factors intoaccount in selecting the most appropriate method of protecting an individual structure.These factors include effectiveness, environmental performance, cost and programmeimplications, interaction with adjacent structures and compatibility with other mitigationmeasures.

10.1.6 The nominated undertaker will carry out defect surveys of all structures within the zoneof significant settlement before construction starts in the area. This is a written andphotographic record of any existing cracking and deterioration of finishes and structurescarried out by a chartered building surveyor commissioned by the nominatedundertaker.

10.1.7 The need for monitoring will be determined on a case-by-case basis. For significantexcavations monitoring will generally commence six months prior to commencement ofthe works and continue for six months after significant ground movement has ceased.In general, it will consist of surveying of studs or targets installed on the outside ofbuildings or inside subsurface structures but other techniques may be used such asautomatic monitoring devices linked to a monitoring centre.

Provisions in Relation to Listed Buildings

10.1.8 Buildings, which are listed as being of national architectural or historic interest, will besubject to particular consideration. A settlement assessment has already beenundertaken for these buildings in order to inform the assessment. This has consideredthe impacts from settlement on sensitive features and the heritage value of the building.Protective measures will be undertaken where necessary to protect the building or itsimportant or valuable heritage features. Where protective measures are necessary, theselection of the appropriate method will be undertaken in consideration of the potentialimpacts of the works on the heritage value.

10.1.9 The specific mitigation measures to be used for each building will be determined duringthe detailed design and construction planning phases. Once the details of theconstruction and the techniques and equipment to be used have been fully determined(but prior to the commencement of construction), the potential settlement of eachbuilding will be reviewed. Where protective works are deemed to be necessary, these willbe designed accordingly. The selection of the measure will be informed by the settlementassessments, internal inspections of buildings, including data on particular sensitivitieswithin buildings, and on the robustness and stiffness of building foundations.

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