Mayor Support

8/2/2019 Mayor Support

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Appendix 1Thames Tunnel Phase 2 Consultation ResponseMayor of London

1 This appendix contains the Mayors and TfLs detailed comments on the followingaspects of the Thames Tunnel proposals:

General issues in relation to tunnelling and construction sites Site specific comments on the 24 preferred construction sites Route of the main tunnel and connecting tunnels under TfL assetsOverview of Changes since Phase 1

Consultation2 Thames Water has worked up the phase 1 consultation proposals for the Tunnelinto more detailed proposals. This has resulted in changes to all sites. In some casesthe changes are minor in terms of strategic impacts, in other cases there are moresignificant changes including a number of sites which have been moved altogether. Thepreferred Tunnel route has remained broadly the same, although there are importantchanges to the tunnelling methodology and direction from some sites.

3 The overall proposal is for a tunnel, broadly underneath the Thames betweenActon Storm Tanks and the Lee Tunnel at Abbey Mills (which is currently under

construction). The tunnel will have a number of connection points along its route toenable the combined sewer overflows to discharge into the tunnel. The tunnel will be6.5m diameter between Acton and Carnwath Road, Fulham and 7.2m diameter betweenCarnwath Road and the Lee Tunnel. The tunnel will transfer captured flows to BecktonSewage Treatment Works. This is broadly the route as proposed by the ThamesTideway Strategic Study in 2005.

4 There are also connecting tunnels from other parts of the sewer network into themain tunnel. Whilst these are all smaller and shorter than the main tunnel, some ofthem are major engineering projects in themselves, notably:

Frogmore Connection Tunnel between King Georges Park and the Main tunnelvia Bell Lane Creek - this is approximately 2.6m diameter and 1.1km long

Greenwich Connection Tunnel between Greenwich to Chambers Wharf, viaDeptford Church Street and Earl Pumping Station this is approximately 5mdiameter and 4.6km long

There are a number of other short connecting tunnels also required at individualCSO connection sites

5 The tunnel is proposed to be constructed at depths in excess of 35m belowground level and up to 75m below ground level. This takes the tunnel beneath all tube,rail, road and foot tunnels and beneath all known other utility services. Connecting

shafts are required at 17 sites to connect the existing overflow points along the river tothe tunnel. The connection shafts are significant engineering projects in themselves,

Appendix 1Mayors Response to Thames Tunnel Consultation Phase 2

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6 The main tunnel drive sites are situated at locations close to changes in geology,and are influenced by land availability and safe tunnelling distances.

7 The tunnelling drive programmes are set out below: (tunnelling not set outchronologically, some drives will be going on at the same time)

Proposed Tunnelling Drive sites

Carnwath Road to Acton Storm Tanks Kirtling Street to Carnwath Road Kirtling Street to Chambers Wharf Chambers Wharf to Abbey Mills Greenwich to Chambers Wharf Bell Lane Creek to King Georges Park Bell Lane Creek to Main tunnel8 In response to the Phase 1 consultation the Mayor stated a preference for theAbbey Mills Tunnelling route. This was, and remains Thames Waters preferred route.The Mayor continues to support this route because it offers the shortest option thatcaptures the relevant sewer overflows. It therefore entails the least disruption andlowest cost.

9 Suggestions of alternative tunnel routes and strategies have been made duringthe consultation period. The Mayor encourages both Thames Water and others to

continue to consider alternatives, especially if they have the potential to reduce costsand disruption. However, of the alternatives that the Mayor has been made aware ofthus far, the Mayor sees little merit in them. In particular the proposal from the ThamesTunnel Commission that a shorter tunnel between Acton and Kirtling Street should beimplemented on its own, the Mayor finds unsatisfactory. Not only would this proposalfail to address the CSOs in central and east London, but it would suffer from aconsiderable problem in disposing or treating the captured combined sewage due to alack of capacity in sewers running through central London to the main sewagetreatment works in east London. The Mayor would be concerned that if such a proposalwere to be implemented it would be a relatively short period of time, say 10-20 yearsbefore the tunnel would need to be extended to connect to the Lee Tunnel. In such

circumstances the increased disruption and further lack of suitable sites can be expectedto increase costs even further.


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General issues in relation to tunnelling andCSO connection construction sites

General

16 It is clear that any construction project of this scale is going to lead to disruptionand impacts. These effects are exacerbated as the project necessarily needs to beundertaken in the densely developed and populated core of London with its complexarrangement of infrastructure, buildings, congested roads, open spaces andhistoric/cultural assets. It is imperative that Thames Water minimise the constructionrelated impacts at all available stages. This is particularly important given that this is aproject specifically to improve the environment. The changes to the proposal havegenerally moved to reduce impacts. However, it is clear that there are a significantnumber of issues that are yet to be clarified or resolved.

17 The Phase 2 consultation material gives further information on the nature ofconstruction impacts, however this still falls short of giving a complete picture. Inparticular the Mayor has concerns in relation to work that is on-going and not availablefor the Phase 2 consultation.

Transport

18 The Mayor recognises that the Thames Tunnel project presents a logisticalchallenge to the promoter but he must ensure it is delivered in an acceptable way inTransport terms. There is one site, Greenwich, where there is a fundamental problemwith the position of the shaft and there are several sites where there are significanttransport related concerns that cannot be fully assessed with the material available atpresent.

19 London Plan policy 7.26 and Mayors Transport Strategy both support the use ofthe river for freight movement and in particular the movement of bulk materialsassociated with construction sites located near to the Blue Ribbon Network. Rivertransport can play a significant role in mitigating the impact associated withconstruction activity and in particular the reduction of lorry trips on the road network.

20 The cost effective maximisation of the use of the river and/or rail is key to this.This will be an important factor in reducing the impact of the scheme overall by

reducing the number and frequency of HGV movements on congested and sensitiveparts of both the strategic and local road network of London. In the Phase 2documentation the use of the river is limited to part removal of tunnel arisings,cofferdam infill import and removal and limited deliveries by barge. This will beparticularly important at the three principal proposed tunnel drive sites (Carnwath Road,Kirtling Street and Chambers Wharf). It is also important at sites where access isconstrained (Putney Bridge for example) or where sites are immediately adjacent to verysensitive corridors such as Victoria and Chelsea Embankments. Furthermore theGreenwich PS site will be the excavation point for the Greenwich connection tunnelwhich at 5m diameter and 4.6km long will be a major excavation in the vicinity of acongested area of the road network. It is disappointing that the proposals are not more

positive about the use of barges here.


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21 Furthermore a nominal figure of 70m increase in project costs has beenidentified to account for the use of barges. TfL has not seen the evidence orbreakdown of this cost and therefore cannot comment on whether it is a reasonableestimate or to what extent other impact costs (such as air quality, congestion andsafety) can be averted. Furthermore it is highlighted that many permanent facilities

such as transhipment points and new rail heads are being put in place by the currentCrossrail major project and that if Thames Water were to install further facilities, thesemay themselves have a value for other uses after completion of the Tunnel. Theidentification and appraisal of these facilities should be explicitly considered andopportunities for use explored and identified within expected social cost benefitanalyses.

22 There are also some suggestions of potential rail opportunities but these do notappear to be worked through at this stage. Therefore it is evident that modes otherthan the road (both water and rail) are not maximised within an acceptable cost marginat present and it follows that the current proposed transportation logistics isunacceptable.

23 One element which is of paramount importance to any major scheme such as this,is the Construction Logistics Plan (CLP) which has yet to be developed by the schemepromoter, although given 20 or so pages of text within Volume 2 of the PEIRdocumentation.

24 Thames Water recently (Jan 2012) confirmed to TfL/GLA that the TransportStrategy Study is being developed outside the Phase 2 consultation. This limits thedetail into which these comments can go at this stage. TfL would encourage that sucha study fully addresses the comments contained within this response. We would urgeTW to engage with all stakeholders during the undertaking of this task, consulting with

affected London Boroughs at the earliest opportunity. TfL have consistently andcontinually placed such a study as the priority piece of work required and it is regretfulthat such a study was not undertaken earlier so that the collective findings could havebeen incorporated into Phase 2 consultation and used to inform the wider community.

25 The following comments are therefore based only upon published Thames TunnelPhase 2 consultation material. We would take the opportunity to highlight that fromTfLs perspective we would wish to promote a logistics plan that:

Maximises the use of river and rail transportation Minimises impact on the strategic and local highway network Minimises overall and local environmental impacts Is cost effective considering all direct and indirect costs and benefits consistent

with established Government guidance on transport investment

26 In TfLs comments contained within the Mayors Phase 1 response, TW as thescheme promoter was expected to address handling issues cited as being the reason fortunnel and shaft linings not being proposed to be delivered via the river and recognisethat barges also offer storage facilities which can reduce work site areas. Issues andfactors such as these have still not been addressed and we would expect these to beexplained fully within such a Construction Logistics Plan.

27 The scheme provides the opportunity to enhance pedestrian, cycle and vehicleinfrastructure and general public realm within the environs of each of the work sites.Appendix 1Mayors Response to Thames Tunnel Consultation Phase 2

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Impact on Highway Network & All Users during Construction

28 Given the scale of this proposed scheme the Mayor remains concerned about thepotential impacts of the scheme during construction on the Transport for London RoadNetwork (TLRN) and all its users. To ensure that safe and efficient transport operationsand infrastructure can be maintained during construction it is essential that theseimpacts are identified and minimised through appropriate mitigation measures.Therefore, some key issues yet to be resolved with TfL are:

29 Assessing Impact on Highway Network & Users: It is important thatappropriate strategic and local traffic modelling is undertaken to inform the overallTransport and Environmental Assessments being undertaken by the scheme promoter.This work has still not yet been completed by the scheme promoter and will help ensurethat the scheme impacts are mitigated against and adequately managed. It is importantthat TfL agrees the scope and methodology of the traffic modelling and transportassessment process. At present full agreement on these processes has not yet beenreached. TfL anticipates making further comments on the scheme once the TransportAssessment has been completed.

30 We note that the phase 2 consultation documentation presents daily average HGVflows at each site (derived from monthly average HGV flows). TfL remains concernedthat use of these average flows in these assessments will under-represent both the localand strategic impacts of the scheme. The forecast vehicle demand flows to be used in

any traffic modelling and transport assessment must be discussed and agreed with TfLto ensure it is appropriate.

31 It is noted that a secondary tunnel lining, comprising an additional layer ofreinforced concrete may be required and that this shall be clarified in future designwork. The scheme promoter is requested to prioritise this piece of work and confirm towhat degree such a requirement is included within Traffic modelling figures and foreach site duration programme. It is noted that if required the necessary works would beundertaken 24 hours /day with site batching of concrete being necessary. This raisesfurther questions on other areas, noise levels for example, which may be impacted uponand similar confirmation is sought as to works effects at the earliest opportunity.

32 Construction Logistics Strategy: Fundamental to minimising the degree ofimpact on the TLRN will be the preferred approach of the scheme promoter toConstruction and Logistics Management (both scheme-wide and at each specific site).This will determine the strategic and local mode share between highway and river basedconstruction traffic, and in turn the scale of scheme impacts on the highway networkand various TfL operations and assets.

33 As the Construction and Logistics Strategy is not yet available it is not clear fromthe Phase 2 material what alternative approaches to Construction Logistics have beendeveloped and considered (including greater use of river transport), how they havebeen assessed (their costs and benefits) and why the currently preferred approach wasselected.


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34 Implementing the Construction Logistics Strategy: It is not clear from thePhase 2 consultation materials, or from discussions with the scheme promoter, how theywill ensure that the contractors appointed to construct the scheme will deliver materialsin accordance with this strategy. Within the Phase 2 consultation literature there isreference to contractor flexibility, TfL is not aware how the scheme promoter will

ensure that Consented Project Requirements are delivered. TfL is concerned as to theguarantee that such mechanisms are put in place and, if they are, prove effectiveenough to ensure that commitments made by the scheme promoter to a strategy thatutilises river transport are monitored and met.

35 Day to Day Management of Construction Logistics (HGV Routing, SiteOperating Hours, Abnormal Loads, Traffic Management Arrangements): Whilstthe phase 2 consultation material proposes routes for HGVs during the constructionperiod it will be vital that the scheme promoter establishes a resource or team tocentrally coordinate and manage all construction logistics activity across the scheme.One of its remits will be the need to provide the adequate enforcement of agreed routesby any construction traffic to the satisfaction of TfL. Close liaison between this functionand TfL/other local highway authorities will help ensure that the most appropriate HGVroutes, delivery hours etc are selected for each site based on the latest networkconditions and other works taking place at that time. It will also be essential to help TfLand the various highway authorities in their network management duties.

36 Road Safety: Minimising the risk of collisions arising from the proposed schemeworks is essential. The proposed scheme will generate significant HGV movements onthe network, which will increase the risk of accidents, particularly for vulnerable roadusers such as cyclists and pedestrians. It is notable that a number of the lorry routes arealong roads containing existing or proposed Cycle Superhighway routes. All proposedsite accesses, traffic management arrangements, diversionary routes (for vehicles,

pedestrians and cyclists) etc must all be designed and appropriately assessed (safetyaudit) so as to minimise the risk of accidents. TfL would encourage the use of blindspotsafety mirrors (trixis) at each of the construction sites. A final version of the TfLsCyclists at Roadworks document should be available shortly and should be referred towhen finalising traffic management designs.

37 Maintaining Operating Capacity and Journey Time Reliability for Users:Works at a number of proposed sites (eg. Blackfriars, Victoria Embankment, ChelseaEmbankment, Deptford Church Street) will significantly impact on highway capacity forextended periods of time. This would have significant impacts on journey times andreliability for users of the network, including bus services. TfL is very concerned that

every effort is made to look at ways to minimise the need for any works that require theloss of any lane capacity. If works must take place then they should be for as short aperiod as possible and appropriate mitigation measures put in place.

38 Site Design Workshops with TfL/Transport Assessment: TfL has alreadyraised a series of detailed comments regarding the scheme and the proposed work sitesat a series of workshops. Many of these comments are covered below but some are not.We recognise that these comments have been captured by the scheme promoter andwould highlight that these comments are still relevant. Many have not yet beenaddressed by the scheme promoter and require further work. TfL is also anticipatingmaking further comments once a draft Transport Assessment and other documents have

been submitted by the scheme promoter.(see comments on individual sites)


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39 Tree Removal and Replacement on Embankment: Further discussions withTfL are required regarding proposed tree removal and replacements at sites on Victoriaand Chelsea Embankment. At locations where tree removal proves unavoidablesubstantial replacements will be required (TfL will provide more detail on exact treespecifications). The viability of replanting will need to be determined prior to any

removal. To help mitigate the loss of mature trees along the Embankment TfL alsosuggests there are opportunities as part of this scheme for some succession plantingand would welcome the opportunity to discuss this further with the scheme promoter.Note that tree planting near to flood defences may require flood defence consent fromthe Environment Agency (EA). The scheme promoter will need to consult further withthe EA regarding any proposed tree planting plans (following approval of the plans fromTfL).

40 Mitigation Measure costs: The cost of any identified mitigation measure to TfLhighway network (eg. Required junction improvements), assets (eg. Piers) or services(eg. Bus operation costs for service diversions and changes to facilities) would need tobe met by the scheme promoter.

Impact on existing assets owned by TfL

41 Ordinarily for 3rd party projects such as this, as previously advised, TfL wouldexpect a 3rd party interface agreement and set of protective provisions that fully assureTfL in respect of all of its concerns and otherwise regulates the acquisition, temporaryoccupation or granting of rights in respect of any of TfLs land relative to any CPOpowers TWUL may secure, whereby either:

(i) Rights or interests are granted consensually for which purpose anyagreement would include a prohibition on TWUL exercising any CPO powers

against TfL; or,

(ii) TWUL exercising any CPO powers in an agreed way, for which purpose anyagreement would include obligations regulating TWULs exercise of CPOpowers.

(a)Depending how any wider agreement with TfL develops, any TfL subsidiary maywell require its own bespoke agreement with TWUL to cover the above pointsand the scheme promoter interfaces specific to any TfL subsidiary consistentwith the MOU and any successor agreements, any TfL subsidiary must reserveits position.

(b)It is considered that with respect to LU infrastructure, all issues are beingmanaged effectively through the formal approval process which shall continuewith the scheme promoter. It is confirmed by LU that within Phase 2 alignmentproposals all crossings are being picked up through the recent ongoingPreliminary Impact Assessments from The Thames Tunnel team. One crossingof the Jubilee Line Tunnels from the long connection tunnel from ChambersWharf Shaft under St Jamess Road had not been covered in our recentinspections but it has been agreed with the scheme promoter to be covered inan Impact Assessment in due course. None of the above to be assumed asagreement to the proposed DCO wholly or in any part.


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(c)Further assessment work, discussions and approval processes will be required forworks to existing Piers and embankments owned by TfL.

(d)The Mayor will expect such agreements to be binding and secured in anyDevelopment Consent Order.

Transport Environmental Issues

42 When considering the EIA, NSIP and the IPC it would be useful for the schemepromoter to explain the level of detail that will be assessed and the potential need toprovide for some flexibility on detailed design and how this will be assessed. The IPChas a useful guidance note on this entitled Using the Rochdale Envelope albeit this hasbeen drafted with wind farms in mind. We would also request that the inter-relationshipwith the requirements of other consents and licenses (eg. From the EA/MMO/PLA etc.)are explained.

(a)Within Volume 1 of the PEIR Section 4, the Marine Works (EIA) Regulations2007 should be referenced.

(b)Throughout the various volumes of the PEIR there are many references toother future developments. The scheme promoter is reminded that TfL willrequire further reassurance that all of the transport schemes in the MayorsTransport Strategy (MTS)/London Plan either as safeguarded or developed eg.Chelsea/Hackney/river crossings and the developments in the Opportunity AreaPlanning Frameworks (OAPFs) have been fully taken into account.

(c)Within Volume 5 of the PEIR we would advise that there should be reference tothe Mayors Air Quality Strategy (December 2010)

(d)Within future EIA work, future phases of both cycle hire and cyclesuperhighways will need to be accounted for with details provided throughliaison with TfL.

(e)As a more detailed comment, Table 11.4.1 within Chapter 5 of the PEIR hassignificance criteria for hazardous loads which seem subjective the originationor basis of these criteria needs to be defined.

(f)TfL will expect the DCO to set limitations on the power to deviate to the extentthat it might adversely affect a TfL Asset.

Construction Impacts43 Alongside Transport Impacts, construction impacts are the source of the greatestlevel of concern from people living and working close to the proposed work sites. Thisis understandable, particularly when it is not yet clear as to the full extent of thoseimpacts. Even when the impacts are more fully modelled and reported, there willremain a local concern as to the real nature of the construction works. Thames Watershould therefore undertake to establish open Fora for each work site to enable localissues to be discussed and resolved during construction.

44 In order to minimise impacts, it will be important for Thames Water to work withthe relevant public authorities, notably the London boroughs and Transport for Londonfor which bi-lateral discussions are essential. There is also an inter-Boroughs group that


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Air quality Noise & vibration Waste management Land quality Transport (both land and river transport)NoiseSite Selection45 The documentation provided identifies 24 sites that would be necessary tofacilitate the construction of the tunnel. It appears as though noise monitoring at thesesites is ongoing, but broad-brush statements relating to the likely mitigation measuresthat would be required to reduce the construction site noise have been made. These

statements seem sensible, but more information, particularly from the site surveys,would be helpful in considering the noise impacts of the sites more thoroughly. It isnoted that at main tunnelling sites it is proposed to cover the construction shaft with atemporary warehouse style building.

Code of Construction Practice46 At this stage of the project it seems sensible for some common rules to be appliedacross the whole project. With this in mind, a Code of Construction practice (CoCP) hasbeen prepared that looks to provide rules on how the environmental impacts ofconstruction site activity. To date, only Part A: General Requirements is available, butit is stated that Part B of the CoCP will be geared more to the local circumstances at

each of the construction sites. This, undoubtedly, is a response to the fact that a onesize fits all approach will not be appropriate across the 14 Local Authorities that thetunnel is proposed to go through. With this in mind, it could be argued that a one sizefits all approach may also not be appropriate for Part A of the CoCP. In particular,Appendix B of Part A provides guidance on how to apply for a s61 agreement under theControl of Pollution Act 1974. Table B.1 provides an indication of the hours that wouldneed to be used when predicting the noise levels from construction activity. This tableassumes that the standard hours of work for the purposes of the Control of PollutionAct are 08:00 18:00 Monday to Friday, and 08:00 13:00 Saturday. This assumptiondoes not allow for local authority discretion in these work hours.

47

The Mayor will wish to give further consideration to the noise impacts of theproposed sites, once more information is available.

48 Thames Water should make clear the local nature of s61 Agreements under theCode of Construction Practice.

Air Quality49 The GLA's and London Council's Best Practice Guidance (BPG) The control ofdust and emissions from construction and demolitionhttp://legacy.london.gov.uk/mayor/environment/air_quality/docs/construction-dust-bpg.pdf shouldbe implemented across the proposed sites. By the time construction is underway, it is

likely that the BPG will have full statutory status as Supplementary Planning Guidanceto the London Plan and so will be formally required as minimum. This will ensure that


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the construction and demolition activities are managed and thus minimise any nuisancefor existing sensitive receptors.

Odour Impacts

50 The Air Management Plan focuses on the 22 locations that air can enter andexhaust from the sewer tunnel system. As the tunnel system controls combined seweroverflows, it would receive flow intermittently, depending on rainfall. It is estimatedthat in a typical year of rainfall, the tunnel would be empty for about 7075% of thetime, with no air emissions from the majority of sites during this time. When the tunnelis filling, a limited amount of air would be exhausted at sites, depending on how full thetunnel becomes. Air exhausted would be treated to ensure acceptable air quality. In atypical year, most sites would have emissions for five to 50 hours in total, spread overone to 15 events.

51 The odour control is split between active and passive control sites:Active Sites - Active odour control would be undertaken at six of the locations, withexhaust air being treated by carbon filters. These sites would operate continuously at alow rate during times when the tunnel is empty to ensure airflow through the tunnel:

Acton Storm Tanks, Carnwath Road Riverside, Abbey Mills Pumping Station, Greenwich Pumping Station, Beckton Connection Shaft Beckton

52 These sites have ventilation columns generally set 15m above ground level. Eachhas multiple vents from the Odour Control Unit, along with a bypass vent for whentreatment capacity is exceeded. This is intended to be once in every fifteen years. Airintake would primarily be at Blackfriars Bridge Foreshore and Greenwich PumpingStation.

53 Passive Sites - The remaining sites would be passive plants that would treat airbeing discharged whenever the tunnel fills with exhausted air being passed throughpassive carbon filters. The passive sites have ventilation columns set at a height of 4 m(complying with hazardous zoning requirements under Thames Water standards).

54 When the tunnel starts to fill with wastewater, shafts gradually fill and displace theair inside them. This starts at the eastern end of the tunnel first. This means easternsites would vent/be drowned out more frequently with 25-50 hours each year,compared to 5-15 hours in a typical year at the western end. This venting would all gothrough charcoal filters (at both active and passive sites).

55 Under extreme events, estimated to occur once every 15 years, the capacity of thetreatment units would be exceeded and air from the sewer would be vented directly viathe bypass vent. This is predicted to occur for a period of less than 10 minutes. Whenthe system is full and the Combined Sewer Outfalls revert to entering the river there is

an additional risk of uncontrolled venting (estimated to be on average 10 hours peryear).


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56 The report states that The quality of the air released would be similar to the airquality that is associated with the current CSO discharges and would not cause odournuisance or problems.

57 Details of the odour modelling is cited as being spread across 22 volumes of thePreliminary Environmental Information Report and has not been compiled as a technicalannex for the Air Management Report. The report outlines minimum maintenance andinspection routines:

Active sites would be visited once a week, whilst passive sites would receive aquarterly inspection and maintenance check, covering:

a. monthly check of duty/standby fan and motorsb. annual checks on residual lifetime of Odour Control Unit (OCU) mediac. retention of critical spares for each OCU

58 There is a commitment to rectify normal and abnormal faults within 48 hours.No indication has been given of any monitoring programme other than H2S to beundertaken as part of the inspections.

59 The report outlines a preliminary complaints procedure, through reporting toThames Water Customer Services Central Customer Centre followed by a checking andvalidation procedure. No indication is given with regard to the speed of the complaintvalidation, or any reporting of problems to relevant local authorities or the GLA.

60 In paragraph 2.3.4 of the Air management Report, the relationship between thebypass vent and the separate vent structure with weighted dampers is unclear,particularly in respect of the expectation of operation once every 15 years. Para 2.3.5

does not clearly detail the relationship between normal conditions and when theweighted pressure relief dampers are open.

61 The report states that The odour concentrations at ground level and at elevationbeyond the site boundary at each site have been modelled in relation to the 98thpercentile of hourly odour concentrations in a year and also the concentrations atbuildings where people could be exposed. However no clear details are provided in thedocument. Preliminary modelling results are cited as being presented in volumes 7-28of the Preliminary environmental information report (PEIR). These volumes do notappear to be in the Document Library and therefore the absence of any detail on thesehas meant that it has not been possible to assess these.

62 In any case, the Mayor does not consider it reasonable to reference technicaldetails across 22 separate volumes without producing a more detailed summary of thefindings beyond the statement The modelling results presented in the PEIRdemonstrate that with the air management system developed, there would be nosignificant risk of nuisance odours associated with the Thames Tunnel project. All of thesites would achieve the 98th percentile odour criterion.

63 Paragraph 3.4.4 suggests that active OCU sites would be visited once a week but provides no indication of the inspection or maintenance.

64 Whilst having a monitoring programme for H2S can identify some elements ofodour, it is not the only odorous compound associated with wastewater treatment. TheAppendix 1Mayors Response to Thames Tunnel Consultation Phase 2

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65 Paragraph 3.5.1 mentions motorised dampers, however these have not beenclearly described elsewhere in the report (presuming they are different to the weighted

dampers described in section2).

66 There is no process set out for keeping public or regulatory bodies informed ofcomplaints, or problems with the operation of the system.

Odour Conclusions

67 The information provided thus far does not enable a full assessment of the odourimplications. The information has not been provided coherently, rather this has beenloosely referenced simply as being presented in 22 separate volumes of generalpreliminary environmental information which do not appear to be on the documentwebsite. In the presentation of an Air Management Plan such as this it would beexpected that these details would be assembled in a single Technical Annex that wouldbe simple to access.

68 However, under normal operating conditions it is not expected that there will beany significant increases to untreated odour emissions, assuming that the equipment isoperating correctly.

69 Extreme events requiring the untreated venting of air are anticipated to occur onlyonce in every 15 years. Whilst undesirable, this is felt to be reasonable.

70 The proposed mitigation and control methods appear to be satisfactory under thecircumstances set out in the Air Management Plan, and are therefore consideredunlikely to pose a significant risk of causing undue odour problems. However,insufficient evidence was available to check the robustness of the scenario outlined inthe main Air Management Plan report.

71 Whilst rudimentary details of inspection, maintenance, and complaints proceduresare given and generally appear to be acceptable, there is no clear indication of howoverall operations will be recorded and, where necessary reported on to relevantpublic/regulatory bodies.

72 Suitable arrangements should be ensured to control, manage and address anyunforeseen problems should they arise once in operation.

Waste

73 The project will result in the excavation of a large amount of tunnel spoil. Earliercomments have already indicated an imperative to ensure that the vast majority of thisis transported using water transport. In parallel with this, further consideration isrequired to identify the most beneficial use for the spoil and whether it is suitable for apositive use as aggregate material. In particular it would be beneficial to examinewhether any of the early shaft excavation material or excavation material from otherprojects, notably Crossrail or National Grid Tunnelling, could be used as infill material

for the cofferdam sites in the River.


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74 The landfill diversion target of 90% is considered appropriate to begin with,however it is suggested that a reuse and recycling target of 95% should beimplemented by 2020 at the latest for the project as a whole. This will bring the projecttarget in line with the London Plan target which is important given that this project willgenerate a significant percentage of London's annual Construction, Demolition and

Excavation (CDE) waste.

75 The Mayor welcomes the use of the Waste Hierarchy as a guide for this strategy. Hewould however like to see more emphasis on waste reduction and over the course of theproject, would like to see ambitious targets set for limiting the amount of wastegenerated in the first place. Further detail on how the Waste Hierarchy will inform thepre-construction stages of the overall project and the individual site projects - e.g. theplanning and design, through to material specification and procurement stages.

76 The use of reused and recycled materials in construction should be an integralconsideration right from the design stage onwards through specification, contract and

construction. It is suggested that a target for the use of reused and recycled materials isset from the outset in order to drive the work of the various contractors. The Site WasteManagement Plan monitoring process could be used to understand if this target wasbeing planned for and met by the individual site contractors.

77 In respect of demolition waste, surveys of existing buildings or infrastructure, toidentify potentially reusable and recyclable materials, are carried out well in advance ofdemolition. Further, arrangements should be put in place to allow for such materials tobe recovered prior to demolition.

78 Detailed Waste points: Para 5.4.12 of the Waste Strategy says that '[C]ontractors would be encouraged to

improve segregation of different waste types on site". This should be strengthenedto become a requirement unless demonstrably impossible due to site constraints.

Para 5.4.16 of the Waste Strategy states that contractors would be encouraged tomake use of local permitted and exempt facilities that accept, process and recycleconstruction materials. This should be a firm requirement.

Special consideration should be given to the potential for recycled material contentin concrete used for the project, given that concrete is the most significant materialbeing used. The potential for use of cement and aggregate substitutes, such asChina Clay sand and incinerator ash, should be looked at well in advance and shouldbe built into specifications and contracts with the principal contractor, whereappropriate.

On-site treatment of excavated material, for use as fill material, should be exploredin sites where there may be space available.

A target of 70% recycling is suggested for welfare waste, with appropriate facilitiesand monitoring procedures put in place.

Energy

79 This project will create a considerable demand for energy in many aspects.Initially, the construction of the tunnel and all the CSO connection sites will involve

large amounts of energy in transporting large volumes of materials, estimated at 8


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80 The operation of the tunnel will represent a large and on-going commitment toenergy use, both directly in pumping the captured sewage overflows and less obviously

in the increased flows through Beckton Sewage treatment Works. The Mayor is awarethat calorific value from sewage is captured at the sludge powered incinerator atBeckton, but also that the calorific value from the sewer overflows is relatively lowbecause there is a high proportion of rainwater.

81 Thames Water need to ensure that energy demand, and the carbon emissionsrelated to this, are considered and minimised in all elements of the project from theenergy used in tunnel construction and spoil transportation to embodied energy intunnel materials.

82 Thames Water also needs to examine opportunities for on-site low or zero carbonenergy generation. The Mayor is not yet convinced that all opportunities to achieve this

have been taken. Through discussions Thames Water has indicated that capturingenergy from the sewer overflows entering the tunnel and flowing along it is notpractical. While understanding the difficulties, the Mayor urges Thames Water to keepan open mind to opportunities to capture some of that energy. The project should alsoconsider possible links to support wider energy generating and distributioninfrastructure, especially in key development areas such as Nine Elms or near theSELCHP plant in Lewisham, where viable opportunities for decentralised energy andspecifically district heating networks have been identified.

River Impacts

83 The construction works and permanent works will result in direct impacts on theriver and its foreshore in many locations. These impacts will need to be investigatedand assessed in more detail. Of particular concern are the hydraulic impacts that morestructures in the river may have on river flows. In many locations the introduction ofsuch structures may lead to either increased erosion or increased sedimentation. Theseeffects may prove damaging to other river structures and to navigation, and, if notdesigned out may need on-going management, for example by dredging. Changes toriver flows will also impact on navigation and could lead to difficulties for riverpassenger, freight or leisure/tourist services. The Mayor is aware that further work onthese issues has been undertaken since the Phase 1 consultation. However, this workhas not yet reached a full conclusion and further detail is required. The Mayor will seek

advice from the Port of London Authority and Environment Agency on these aspects.

Design and Heritage

84 Whilst it is appreciated that designs are not finalised, Thames Water will have topresent improved design options for the sites in the Development Consent Order (DCO)submission. This will apply both to the screening, fencing etc of construction sites andto any permanent structures visible at surface level. Many of the sites are in sensitivelocations with Listed Buildings and Structures and Conservation Areas adjacent ornearby, some of these structures are amongst the most high profile heritage assets inthe country. In addition some of the structures are close to or within viewing corridors

of important buildings within London. The original sewer scheme by Bazalgette has set


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85 Since Phase 1 Thames Water has presented proposals for each site to the DesignCouncil/CABE. This has generated a good deal of useful advice to the design team in

continuing to develop the proposals.

Legacy/Re-instatement

86 The re-instatement works following the construction should achieve a positivelegacy. This will require a clearly thought through approach to the sites individually andas a series. Thames Water should work with the Mayor, boroughs and local interests todesign and deliver these improvements in line with local priorities, the principles of theMayor's manifesto for improving public spaces, London's Great Outdoors and the AllLondon Green grid. This should include the introduction of the Legible Londonwayfinding scheme and consultation with TfL. The re-instatement works shouldincorporate cycling infrastructure for example secure parking, Barclays Cycle Hiredocking stations wherever possible and appropriate within the public realm strategy forthe legacy.

87 Of particular concern is the fact that many of the sites will not be re-instated forseveral years, some in excess of 10 years. During this time we can expect many changesto local circumstances and new opportunities, for example through new development,that could not be anticipated at present. Therefore it will be important for ThamesWater to retain a degree of flexibility in respect of legacy/re-instatement proposals.

88 Many of the construction sites will retain overflow points to the Thames for timesof excessive rainfall. Consideration should be given at this stage to fitting monitoring

equipment to check the performance of the Tunnel during operation.

Property

89 GLA /TfL will expect any occupation of its property by Thames Water to be on thebasis of agreement as opposed to by exercise of powers. There are issues that TfLGroup Property would wish to see addressed in agreements prior to Thames Waterentering onto TfL sites. References to such issues need to be consistent with mattersthat need to be covered in subsequent legal agreements.

Integration with other major construction projects

90 The project is of such a scale that it should be integrated with other large projects,which may offer the opportunity for integration and the possibility of sharingconstruction and logistics sites and equipment. Crossrail is an obvious example and theshift of timescale of the Thames Tunnel means that the main construction activities willnow follow on from those of Crossrail rather than partially overlapping. This shouldincrease the scope for sharing infrastructure/assets. There may also be otherinfrastructure/utilities projects, such as the proposed Northern line extension, andredevelopment schemes at or close to Thames Tunnel construction sites, not least ofwhich will be development of the Vauxhall Nine Elms Battersea Opportunity Area. The

shared use of barge transport facilities and sites should be explicitly considered.


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Conclusion on general impacts

91 There are a range of potentially serious impacts, mainly in relation to transport,that will have to be addressed by the project. Phase 2 consultation contains lessinformation than was anticipated, especially in relation to transport. The failure to more

fully embrace the river for transport purposes is a serious shortcoming that the Mayorremains to be convinced is justified. Furthermore, due to the lack of information theremay be other aspects of impact on transport modes or structures that may not beacceptable.


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Preferred Construction SitesThe tables below set out the Mayors issues and views on each of the 24 sitesidentified as the preferred sites to deliver the tunnel. For completeness a shorttable is also included for those sites which were in the Phase 1 consultation but areno longer required.

The Mayor objects to the Greenwich Pumping station site as currently designed.

The Mayor has significant concerns about the following sites, although it isanticipated that with appropriate further work these concerns are capable of beingaddressed: Kirtling Street, Chelsea Embankment, Victoria Embankment, BlackfriarsEmbankment and Chambers Wharf.

The Mayor has identified a range of other concerns at the remaining sites.

Site NameBoroughPurposeConstructionPeriod

1 Acton Storm TanksEalingCSO Connection and main tunnel reception siteApproximately 3 years

Key Issues 1. Construction close to residential properties.2. Construction traffic impacts will be all via road requiring new access to

Canham Road. The impacts of this on the surrounding highway network, inparticular The Vale (A4020) have not been fully explored,

3. Ventilation plant is close to industrial properties in Canham Road.4. There are occasional exiting odour problems at this site at present.

Alternatives The alternatives suggested would require the relocation of existing business

premises.Changes sincePhase 1

The Tunnel construction site has been moved to the northern end of the site andaccess has changed from the residential roads to the south and east to the industrialestate to the north. Some of the construction spoil material will be used to fill 2 ofthe existing storm tanks on site. Ventilation plant is further from residentialproperties. There is more scope for bring forward development once construction iscomplete.

Conclusion The Mayor accepts that the preferred option is the best option as it has the fewestimpacts. It has also reduced impacts since the Phase 1 consultation by movingconstruction works and site access to the less sensitive northern end of the site.

However Thames Water need to:

Ensure that construction impacts are minimised to an acceptable level Undertake traffic modelling to ensure that traffic impacts on the road network,

especially the A4020 are acceptable. Opportunities to reduce road distances,potentially by using consolidation centres at nearby barge/rail served sites shouldbe investigated. Examining options for further use of spoil to infill the last 4storage tanks.

Ensure that the location and design of the ventilation plant minimises anynoise/odour impacts on nearby residents.

Options for using the storm tanks to store surface water should be consideredprior to confirming that they will be infilled given the wider issues of surfacewater management in west London.

Legacy

Examine how the site could be brought forward for development upon completion ofthe works.


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2 Hammersmith Pumping StationHammersmith & FulhamCSO Connection3 Years

Impacts 1. Construction close to residential and commercial premises and to PublicOpen Space.

2. Site/adjacent land is also subject to planning permission for a residentialdevelopment

3. Traffic on SRN Fulham Palace Road (A219) and impacts on HammersmithGyratory Phases

Alternatives The alternatives suggested would have higher impacts on Greenfield sites or sitescloser to residential properties as opposed to the brownfield site preferred.

Changes sincePhase 1

The scale of operations has been reduced at this site due to a change in tunnellingmethodology so that this site is no longer required to act as a main tunnel receptionsite and the drive site for a connection tunnel to Acton Storm Tanks.Thames Water has been in negotiation with residential developer to ensure that theTunnel and development can be phased together.

Conclusion The Mayor accepts that the preferred option is the best option as it has the fewestimpacts.However, Thames Water need to:

Properly examine the options of using the river for transport. The local roadnetwork is particularly congested and the residential development should also beable to make use of a river delivery facility. It is disappointing that a more pro-active approach to using barges has not been taken. The proposed quantity ofHGVs, especially in an area where the local road network is so busy, warrantsfurther examination of the use of barges, especially as there should beopportunities to combine such a facility with the importation of materials for theadjacent residential development

Ensure that arrangements are in place to minimise impacts on the re-development of Hammersmith Embankment/Fulham Riverside development -this may include the shared use of any river transport facilities.

Ensure that construction impacts are minimised to an acceptable level. It is likelythat 2.4m acoustic screens be recommended for site boundaries close toresidential properties

Ensure that a good quality Thames Path diversion is put in place. Ensure that the location and design of the ventilation plant minimises any

noise/odour impacts on nearby residentsLegacy:

The design and location of any facilities to support river transport should bedesigned in such a way that they have a purpose following construction such asriver transport or river sports/recreation.

An improved Thames Path and public realm should be re-instated This site will continue to have a sewer overflow to the Thames for occasions

when the Thames Tunnel capacity is reached. Equipment should be installed tomonitor the performance of the system once operational.

The design of finished Pumping Station and boundary wall appears bland andneeds to be improved.


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3 Barn ElmsRichmondCSO Connection2 Years

Impacts 1. Loss of open space/playing fields2. Construction close to residential properties to the south of the site3. Disruption to Thames Path4. Construction impacts on Thames Foreshore5. Limited vehicle access TW are proposing a temporary access road around

the edge of the playing fields, approx 1km long6. Relocation of Scout Hut

Alternatives There are no proposed alternatives to this site as it needs to intercept the existingsewer.


In phase 1 Barn Elms was proposed as a main tunnelling site and a CSO connectionsite. Carnwath Road, Fulham has replaced Barn Elms as a main tunnelling site,therefore the scale and length of works is significantly reduced. The proposal to usethe river for barge transport has been dropped for this site due to the much smallervolumes of material.

Conclusion The switch from Barn Elms to Carnwath Road for main tunnelling purposes issupported as this relocates major tunnelling activities from a Greenfield to a partiallyderelict Brownfield site and increases the viability of barge transport by using acurrently vacant safeguarded wharf.

The remaining works at Barn Elms to connect the CSO to the tunnel are unavoidableand the Mayor accepts that these can be implemented acceptably. However, ThamesWater need to:

Re-examine the access route, it seems disruptive to construct such a long haulroad, although it is also undesirable to have the embankment/Thames path usedfor any intensive lorry movements.

Ensure that the Thames Path remains open with minimal disruption. Options for using the river need to be further explored. Provide suitable replacement premises for the Scout Hut. Agree the proposed relocation of the bus stop on Rocks Lane with TfL. Design of the permanent structures need to be sympathetic to their setting.Legacy:

The design and location of any river jetty should be designed in such a way it hasa purpose following construction such as river transport or river

sports/recreation. This should be determined through liaison with river boatoperators and sports clubs

Thames Water should liaise with school playing field users to identify the re-instatement requirements should be of the site.

An improved Thames Path and public realm should be re-instated This site will continue to have a sewer overflow to the Thames for occasions



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4 Putney Bridge ForeshoreWandsworthCSO Connection3 years

Impacts 1. Construction close to residential properties2. Disruption to river users3. Disruption to Thames Path4. Limited vehicle access5. Nearby passenger pier6. Possible disruption to highway7. Possible relocation of bus stop

Alternatives No alternatives are proposed. The alternatives put forward in phase 1 were lessacceptable than this site.


The duration of construction is now expected to take 1 years longer and atemporary slipway will be constructed 300m to the west of Putney Bridge.

Conclusion The preferred option is acceptable.However, Thames Water need to:

Re-examine the quantity of materials being transport by barge. The use ofbarges to transport cofferdam fill material in phases 1 and 5 is welcomed, but thelack of any barges during phases 2-4 requires further consideration, especially asHGVs will need to be manoeuvred in relatively constrained local roads. It will bevital that appropriate measures are put in place to ensure the safety of all localroad users.


Disruption to the highway and bus operation is minimised and any relocation ofbus stops will require agreement with TfL

Ensure that disruption to the Thames Path is minimised and that pedestriancrossings, diversionary signage are carefully designed and agreed with TfL.

The location and design of the ventilation plant should ensure that anynoise/odour impacts on nearby residents are minimised.

It is welcomed that a temporary slipway will be installed given the prominence ofriver sports at this location.

Legacy

An improved Thames Path and public realm should be re-instated with suitablere-instatement of the river access facilities/slipway should be provided followingliaison with river users. It is a concern that the design of the permanent structureappears somewhat unsympathetic to the alignment and character of the

river/embankment at this point. This site will continue to have a sewer overflow to the Thames for occasions



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5 King Georges ParkWandsworthCSO Connection2 Years

Impacts 1. Loss of open space, including some large trees2. Impact on Metropolitan Open Land3. Construction close to residential properties4. traffic impact on the TLRN.

Alternatives No alternative is given in the consultation material and no site is thought to bereadily available that would cause fewer impacts.


The proposed construction period is 6 months longer. Changes to the layout havebeen made to protect an existing mature tree and memorial bench.

Conclusion The preferred option is acceptable. The site forms a relatively small proportion of alarge park.However, Thames Water need to:

Ensure that disruption to the park is minimised Assess the impact of construction vehicles using the adjacent TLRN Wandsworth

one way system any necessary adjustments be agreed with TfL.

Investigate opportunities to reduce road distances, potentially by usingconsolidation centres at nearby barge/rail served sites should be investigated.

Ensure that construction impacts are minimised to an acceptable level. It is likelythat 2.4m acoustic screens be recommended for site boundaries close toresidential properties and to protect park users

Ensure that the location and design of the ventilation plant minimises anynoise/odour impacts on nearby residents. There appears to be 2 ventilationcolumns, it would be less obtrusive if these were combined into a singlestructure.

Legacy

Thames Water should liaise with LB Wandsworth and park users to determine agood quality re-instatement of the park and public realm.

This site will continue to have a sewer overflow to the River Wandle for occasionswhen the Thames Tunnel capacity is reached. Equipment should be installed tomonitor the performance of the system once operational.


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6 Dormay StreetWandsworthCSO Connection and Frogmore Connection Tunnel Drives3 Years

Impacts 1. Disruption to businesses including LB Wandsworth Depot2. HGV Movements on nearby A217 (TLRN)

Alternatives This site is a new site and is proposed as an alternative to the previous adjacent BellLane Creek site which would have required the relocation of a local business,Panorama Antennas. The alternative shown appears to have similar impacts to thepreferred site.


New siteThe Mayor raised concern at the impact on the local business affect by the Phase 1proposal, therefore this change is generally supported.

Conclusion The proposed site is supported provided that suitable arrangements are in place withLB Wandsworth to manage the impacts on the LB W Depot. However Thames Waterwill need to:

Agree modifications to the design of the Dormay Street/Armoury Way junctionwith TfL. Dormay Street Figure 2E should be left turn out not right turn out.

Examine opportunities to reduce road distances, potentially by usingconsolidation centres at nearby barge/rail served sites should be investigated.

Legacy

Ensure that the site is available for productive uses, which are likely to beindustrial/storage/distribution, once construction works are complete.

This site will continue to have a sewer overflow to the River Wandle for occasionswhen the Thames Tunnel capacity is reached. Equipment should be installed tomonitor the performance of the system once operational.


Bell Lane CreekWandsworthNo longer required formerly a CSO ConnectionNone

Impacts n/a

Alternatives Dormay Street is now proposed as the replacement to this site.

Conclusion The Mayor welcomes the change of preferred site in this location, subject

to agreement with LB Wandsworth, as it removes an impact on anexisting local business.


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7 Carnwath RoadHammersmith & FulhamMain Tunnelling Site to Acton Storm tanks and reception site from Kirtling Street6 Years

Impacts 1. Construction close to residential properties to the north, east and west ofthe site

2. Loss of light industrial businesses3. Loss of vacant safeguarded Hurlingham Wharf4. Loss of potential development site at Whiffen Wharf5. Additional vehicle movements on Carnwath Road and on surrounding routes6. Use of 2 barges/day

Alternatives This site is the alternative to Barn Elms as a main tunnel construction site.


New site in Phase 2.

Conclusion The switch to Carnwath Road from Barn Elms for main tunnelling purposes issupported as this relocates major tunnelling activities from a Greenfield to a partiallyderelict Brownfield site which benefits from good navigational characteristics andbetter access to the Strategic Road Network. However Thames Water will need to:

Ensure that existing businesses on site are relocated to suitable alternativepremises with minimal disruption

Ensure that existing residents are protected from noise and dust. The proposal toenclose the shaft and crane within a building is welcomed, subject to ensuringthat it meets the noise, dust etc requirements.

Re-examine the extent to which river barges are being used at this site. The 2barges per week during phases 2 and 3 are welcomed however, this still leaves asignificant number of HGVs visiting the site over a six year period. The Mayorremains un-convinced that more of these cannot be switched to barge deliveriesas the site is particularly well suited to barges.

Undertake traffic modelling to ensure that traffic impacts on the road networkare acceptable, especially on Carnwath Road, Wandsworth Bridge Road and the

junction. Any proposed modifications, will need to be assessed and agreed withTfL.

Potential impact on bus services and stops in the vicinity of this site will alsoneed to be agreed with TfL.

There are schools within a relatively close proximity to the site. Due to theheightened usage and vulnerability of pedestrians connected with these schools,safety of construction traffic will be of paramount importance and to reduce theimpacts (congestion, air quality etc.) of these vehicles.

Legacy:

On completion of construction works, the Hurlingham Wharf site must bereturned to a viable working wharf and that surrounding land can be broughtback into use in line with development plans currently being developed by H&FCouncil.

The design and location of the permanent structures should be agreed with LBH&F but should act as a buffer between residential development to the west ofthe site and the Safeguarded Wharf.

An improved Thames Path and public realm should be re-instated with a suitablediversion inland to Carnwath Road around the Safeguarded Wharf.


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Jews RowWandsworthNo longer required formerly a CSO ConnectionNone

Impacts n/a

Alternatives n/a


The site is no longer required as changes to the sewer system mean thatthe impact of the 2 CSOs at this site will no longer need to beintercepted.

Conclusion The removal of this site is supported as the site currently contains anoperational safeguarded wharf which imports construction materials andwould have required re-provision elsewhere.Legacy

Thames Water should confirm whether any CSOs would still occur atthis site once the Tunnel is complete.


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8 Falconbrook Pumping StationWandsworthCSO Connection3 Years

Impacts 1. Loss of part of open space2. Access onto TLRN3. Relocation of bus stop

Alternatives This site is an alternative to Bridges Court Car Park site contained in Phase 1consultation.


New site which is an alternative to Bridges Court Car Park

Conclusion The preferred option appears to be the best option as it has the fewer impacts thanthe Phase 1 proposal and enables redevelopment of the Bridges Court Car park toproceed.However, Thames Water need to:


Agree final site access junction design with TfL, including provision for theinstalled Cycle Superhighway 8, therefore cyclist safety will need to be aconsideration in the design and assessment.

Agree final arrangements for proposed relocation of the bus stop on A3205 YorkRoad with TfL.

TheshortconnectiontunneltraversesYorkRoadandthere isadropshaft incloseproximity.ItishighlightedthatproceduresfortheTechnicalApprovalforHighwayStructuresoutlinedwithintheDesignManualforRoadsandBridges(DMRB)willberequired

Legacy Discussions with LB Wandsworth should ensure that the re-instatement works

deliver an improved park and public realm.

This site will continue to have a sewer overflow to the River Thames for occasionswhen the Thames Tunnel capacity is reached. Equipment should be installed tomonitor the performance of the system once operational.


Bridges Court Car ParkWandsworthNo longer required formerly a CSO ConnectionNone

Impacts n/a

Alternatives The Falconbrook Pumping Station site is now proposed as an alternativeto this site.

Conclusion The Mayor welcomes the replacement of this site with FalconbrookPumping Station as this will free up a development site and should resultin the improvement of a local park.


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9 Cremorne Wharf ForeshoreKensington & ChelseaCSO Connection3 Years

Impacts 1. Disruption to nearby residential properties2. Disruption to waste transfer station/wharf3. Potential traffic impact on Lots Road and nearby TLRN (A3220/A3212)

Alternatives No alternatives are suggested.


The site has been moved from construction in the Thames Foreshore to on land.This should be a net reduction in cost. The proposed access through the adjacentpark has also been removed.

Conclusion The changes to the site and access arrangements of the site are supported andshould reduce costs and remove the need to access the foreshore via the nearbypark. The use of the safeguarded wharf is considered London Plan policy compliantas long as the majority of construction materials are transported by barge. However,Thames Water need to:

Ensure that the construction minimises disturbance to nearby residentialproperties, in particular those that overlook the Thames and for whom screeningmay be difficult.

Ensure the maximum reasonable use is made of river transportation in order to becompliant with the safeguarded wharf status of Cremorne Wharf and to reducetraffic impacts on Lots Road and the wider network. The Mayor is not convincedthat this has currently been achieved, especially as there may be opportunities toshare facilities with the development of the adjacent Lots Road site.

Undertake traffic modelling to ensure that traffic impacts on the road network,especially the TLRN A3220 are acceptable. The detailed design of the junctionof Lots Road/A3220 will need to be agreed with TfL.

Ensure that there are suitable alternative operating arrangements for the wastetransfer station.

Ensure that the location and design of the ventilation plant should minimise anynoise/odour impacts on nearby residents.

Ensure that the construction of the Tunnel is integrated with construction of theadjacent Lots Road development and that any opportunities to share freightlogistics are taken.

Legacy

On completion of construction works, Cremorne Wharf must be returned to aviable working wharf Ensure that the re-instatement makes provision forcompleting the Thames path in this location.



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10 Chelsea Embankment ForeshoreKensington & ChelseaCSO Connection4Years

Impacts 1. Construction impacts on the Thames Foreshore2. Disruption to Thames Path3. Traffic impact and construction into highway (Chelsea Embankment (A

3212) is part of the TLRN and narrow lane two way working is proposed)4. Impact on Listed Buildings and structures and Conservation Areas

Alternatives Consideration has been given to a site within Ranelagh Gardens. This alternative hasdrawbacks of being closer to residents and occupying an area of open space,however it does have the advantages of reducing the works in the Thames Foreshoreand on the A3213 Chelsea Embankment.


The period of construction is now expected to be 4 years, more detail is available inrespect to impacts on the TLRN and a more sympathetic treatment of the new riverwall is proposed.

Conclusion The choice between the preferred site and Ranelagh Gardens appears finelybalanced, particularly as the currently proposed use of the river for transport is notfelt to be comprehensive (only in connection with the construction of the cofferdamarea). This is not acceptable given that the site is particularly sensitive in trafficterms and that TfL have not yet seen suitable traffic modelling.

The Mayor is not yet convinced that the preferred site is the optimal one. ThamesWater need to consider the following points:

This site is located immediately adjacent to and within the A3212 ChelseaEmbankment, a critical east-west route through central London, whichexperiences significant volumes of traffic throughout the day. Accommodating

the site works and site access proposals would require use of the existinghighway space and a narrowing of existing lanes. This will impact on capacity forroad users and raises safety concerns.

TfL has not yet seen detailed traffic modelling identifying the likely impacts onthe highway network.

Existing highway capacity on A3212 Chelsea Embankment should be maintainedat all times. Where any lane or parking/loading capacity is required this shouldbe a temporary arrangement and for as short a period as possible to minimisedisruption to road users. The impact of these arrangements will need to beassessed (considering the impact of any pedestrian diversions requiring additionalcrossing movements) with appropriate traffic modelling tools and discussed withTfL. Any traffic management arrangements will need to be discussed and agreed

with TfL. The works proposed at Chelsea Embankment, Victoria Embankment and

Blackfriars will all impact on a critical east-west corridor through central London.As a result their impact will need to be assessed together as part of theconstruction logistics strategy and ongoing TA/EIA work being undertaken, anddepending on the outcome of that assessment, careful consideration given to thephasing of works so as to minimise disruption to users.

The works phase 1 site drawings show both the sites on either side of ChelseaEmbankment in operation. TfL had understood that works phase 1 would onlyshow a single site in operation.

It is noted that there is an underground structure planned below the A3212 and alarge drop shaft planned to abut this road. It is highlighted that procedures for

the Technical Approval for Highway Structures outlined within the DMRB will berequired.


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Until these issues have been considered by TfL, the Mayor cannot come to a positionas to whether this proposal is acceptable.

Once a position has been reached, the following issues will remain concerns thatThames Water will need to address:

Any requirement to narrow carriageway widths on the Embankment raises safetyissues, particularly for cyclists. Clearly this will need to be a key consideration inthe design and assessment of proposals in this area. Mitigation measures toaddress this may be required.

The impact of the proposed diversion of the Thames Path will need assessing andappropriate mitigation put forward, including pedestrian crossings, diversionarysignage etc which will need to be discussed further with TfL.

As part of the permanent scheme arrangement changes are proposed to thehighway design on Chelsea Embankment, including changes to pedestriancrossing arrangements. The impacts of these changes on highway capacity,safety etc need assessing and further discussion is required with TfL.

The design of the site access/cross-over to the permanent foreshore appearsover engineered considering the low level of proposed use.

Tree Removal and Planting. The scheme proposes the removal of a number ofmature trees within the highway. This needs further discussion with TfL toexplore options for retaining the trees, to discuss proposed replacement treeplanting at this location and other potential mitigation measures and to ensureadequate measures are put forward to protect other existing highway trees in thevicinity of the site.

Arrangements to allow buses to turn right from A3212 Chelsea Embankment intothe bus turning circle will need to be maintained.

Determine the details regarding how the works will affect the highway, it can beexpected that there will be tight constraints on these works given the congestedand strategic nature of the TLRN.

To reduce the impacts (congestion, air quality etc.) of HGVs accessing the sitefurther consideration should be given to greater use of the river for transportingmaterials to and from this site during construction.

Ensure that the temporary diversion of the Thames Path is of good quality.Legacy

Further work on the completed scheme needs to be undertaken to ensure thatthe re-instatement provides an improved Thames Path and public realmappropriate for this a high profile location.

Discussion are required with river users, TfL, PLA and the LPA regarding thepotential future use of the site for river uses including as a freight wharf or

recreational jetty. This site will continue to have a sewer overflow to the River Thames for occasions



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11 Kirtling StreetWandsworthMain Tunnel Driving site east to Chambers Wharf & west to Carnwath Road,6 Years

Impacts 1. Delays to development of the Vauxhall Nine Elms Battersea (VNEB)Opportunity Area including delivering homes and jobs, subject to currentplanning application

2. Impact on or relocation of riverboat dwellings3. Impact on or relocation of local businesses4. Disruption to Thames Path5. Impacts on Safeguarded Wharves notably Kirtling Wharf6. Potential impact on proposed Northern Line extension7. Impact on the TLRN (A3205 Nine Elms Lane)

Alternatives A number of alternative sites have been examined. Sites south of Nine Elms Lane donot appear to be practical given their remote location from the river and theemerging new development in this area. Site 1 with Battersea Park is unlikely to be

acceptable given that there are brownfield sites available and site 4 is clearly toosmall.Sites 2 and 3 comprise parcels of land in and around Battersea Power Station. Giventhe considerable uncertainties and long term timescale surrounding theredevelopment of the Power Station, these sites are worthy of further, more detailedconsideration. The reasons cited as potential difficulties with these sites, theredevelopment of Battersea Power Station, could in fact be advantages allowing useof a derelict site with good access to the river and the potential to re-use and/orshare river jetty facilities and logistics.


The site has changed due to the grant of planning permission for a residentialdevelopment on part of the previous preferred site. One consequence of the changeis that the local CSO connection is now proposed to take place on a separate site

(Heathwall Pumping Station), whereas these sites were previously joined.The site is now proposed to be a double drive site ie from Kirtling St to CarnwathRoad and from Kirtling St to Chambers Wharf.

Conclusion The Mayor is not yet convinced that this site is the best site to be used and a furtherexploration of the potential of using land in and around Battersea Power Stationshould be undertaken.

If the Battersea Power Station area is not feasible or not preferred following moredetailed examination, the, Kirtling Street site may be acceptable subject to resolvingthe following concerns:

The Mayor remains unconvinced that the full use is being proposed of the riverfor transport. As a double drive site, this will be the site with the greatestamount of construction activity. There should also be opportunities to integratethe use of river facilities with the redevelopment of the surrounding VNEBOpportunity Area and potentially the construction of the Northern Line extensionto Battersea.

Opportunities for utilising rail access to this site should also be explored furthergiven the proximity of the Stewarts Lane sidings and other potential majordevelopments in the area.

The impact on the Nine Elms Lanes junctions (Cringle Street, Kirtling Street),including any proposed modifications, during construction will need to beassessed and discussed further with TfL.

The impact of the proposed diversion of the Thames Path along Nine Elms Lanewill need assessing and appropriate mitigation put forward, including pedestriancrossings, diversionary signage etc which will need to be discussed further with


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There are a number of other major development proposals impacting on this area.To minimise the impact of the proposed scheme it will be important to consideropportunities to work closely with other scheme promoters and coordinate/shareconstruction logistics plans.

It is noted that the site abuts the A3205 and that there is a large drop shaftplanned within the site. It is highlighted that procedures for the TechnicalApproval for Highway Structures outlined within the DMRB may be required.

Details of the interaction between the logistics plan and strategy for this site andHeathwall Pumping Station, needs to be fully examined, discussed andunderstood with careful monitoring during the construction phase.

Thames Water will also need to:

Ensure that the safeguarded wharves of Cringle Dock and particularly theaggregates depot at Kirtling Wharf can continue to operate as freight wharves

Examine opportunities to share construction/waste facilities with thedevelopments within the surrounding VNEB Opportunity Area.

Ensure the suitable relocation of any affected businesses. Ensure suitable relocation of any affected boats. Ensure that the location and design of the ventilation plant should minimise any

noise/odour impacts on nearby residents including future redevelopments

Ensure that the design of both the permanent and temporary works into the riverdoes not cause unacceptable siltation, erosion or other hydrological impacts

Ensure that there is no conflict with the Northern Line extension constructionrequirements

Legacy

Ensure that re-instatement works minimise their impact on the regeneration ofthe area including the development potential of the site.

On completion of construction works, Kirtling Wharf site must be returned to aviable working wharf.

Further work on the completed scheme needs to be undertaken to ensure thatthe re-instatement provides an improved Thames Path and public realmappropriate for this changing location.


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12 Heathwall Pumping StationWandsworthCSO Connection3 Years

Impacts 1. Delays to development of the Vauxhall Nine Elms Battersea Opportunity Areaincluding delivering homes and jobs, subject to current planning application

2. Impact on or relocation of riverboat dwellings3. Impact on or relocation of local businesses4. Disruption to Thames Path5. Impact on Safeguarded Middle Wharf

Alternatives The only alternative presented is to construct the CSO connection in the foreshore.This would have a similar level of impact and be likely to be more expensive.


The site has changed due to the grant of planning permission for a residentialdevelopment on part of the previous site. This CSO connection was previously on asingle site along with the Tunnel Construction activities that are now proposed atKirtling Street, a short distance west.

Conclusion The current site is broadly acceptable.However, Thames Water need to:

Re-examine the use of barges for this site, particularly given the sitessafeguarded wharf designation. The safeguarded wharf is not currently in use,therefore there is no need to re-provide a wharf during construction

Ensure a good quality signposting of the Thames Path, during constructionworks.

Ensure suitable relocation of any affected boats. Ensure that the location and design of the ventilation plant should minimise any

noise/odour impacts on nearby residents including future redevelopments

Ensure that the design of both the permanent and temporary works into the riverdoes not cause unacceptable siltation, erosion or other hydrological impacts

The site abuts the A3205 and that there is a large drop shaft planned within thesite. It is highlighted that procedures for the Technical Approval for HighwayStructures outlined within the DMRB may be required.

Details of the interaction between the logistics plan and strategy for this site andKirtling Street needs to be fully examined, discussed and understood with carefulmonitoring during the construction phase.

Final site access junction design from Nine Elms Lane will need agreeing with TfL. It is noted that there is a large drop shaft planned which abuts the A3205. It is

highlighted that procedures for the Technical Approval for Highway Structuresoutlined within the DMRB will be required.

Legacy

Ensure that re-instatement works minimise their impact on the regeneration ofthe area including the development potential of the site. On completion of construction works, Middle Wharf must be returned to a viable

working wharf. Thames Water has indicated that the design of the permanentstructures is fully compatible with this, and as such this is welcomed.

Thames Water has indicated that a new Thames Path will be created along theriver front, with a gate for times when the wharf is un/loading. This wouldrepresent an improvement on the existing situation where the Thames Path isrouted along Nine Elms Lane.



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13 Albert Embankment ForeshoreLambethCSO Connection3 Years

Impacts 1. Construction in Thames Foreshore2. Access off the TLRN3. Construction close to Victoria Line Tunnels4. Construction risks to TLRN (A202 Vauxhall Bridge) and highway impacts on

TLRN (A3036 Albert Embankment)5. Historic embankment structure6. Construction close to commercial properties7. Disruption to river slipway (Lacks Dock)

Alternatives No alternative locations are proposed for this site.


The proposals now envisage using the Lacks Dock slipway entrance to access thesite.

Conclusion The preferred option is acceptable and the change in access arrangements issupported as it means that an additional access onto the TLRN is not created.However, Thames Water need to:

Further investigate the use of barges to this site. This is particularly importantgiven the location within central London.

Demonstrate suitable arrangements for holding/inspecting vehicles arriving atsite, without disrupting the operation of the TLRN (A3036)

Ensure that constructio

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