Environmental Statement Appendix 3.A (6.3.3.1) Options Summary Table
April 2016
Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
List of Tables Table 1 Options Comparison (Bored and Immersed Tube ‘Base’ options)...... 5 Table 2 Options Comparison (‘Base’ options vs ‘Shortened’ options) ...... 27
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Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Summary Tables extracted from Silvertown Tunnel Options Study, Transport for London (Dec 2013)
Table 1 Options Comparison (Bored and Immersed Tube ‘Base’ options)
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
Air Quality Receptors likely to be Construction Environmental risks and Same as bored The affected include dust can be associated mitigation ‘Base’ option. environmental commercial and mitigated in measures are risks will be the residential accordance with considered to be the same for bored developments located best practice similar to the bored ‘Base’ option and on the Greenwich with the ‘Base’ option as air immersed tube Peninsula and at the measures quality will be affected ‘Base’ option due western boundary of the documented in a by the same level of to similar design Royal Victoria Dock. Construction traffic flow with both and capacity of Environmental options. both tunnel During the construction Management options hence of the scheme works will Plan (CEMP). same level of include the removal and traffic flows storage of excavated There are limited during materials which has the mitigation construction and
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
potential lead to the measures to operation. generation of dust. In control addition dust can be emissions from The same liberated through the vehicles as a number of movement of material by result of the receptors will be vehicles and site plant. Scheme; affected with however the each option. During operation of the attractiveness of Scheme a new road the Scheme layout will be required at could be Greenwich Peninsula influenced by and Silvertown to allow tolling charges. access to the new Silvertown tunnel Ventilation of the crossing. Given that this tunnel can be is likely to result in designed in increases in road traffic order to mitigate there is the potential for any significant deterioration in local air impacts on quality within the receptors (for AQMAs designated by example
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
the London Borough of increased stack Newham and height would aid Greenwich. There are dispersion). likely to be both improvements in air quality and deterioration in air quality at receptors as a result of the change in traffic flows.
Community and At present the land uses No mitigation The immersed tunnel No mitigation Given that the Private Assets in the immediate vicinity measures option, when compared measures land uses in the of the proposed options required. with the bored tunnel, required. vicinity of the mainly comprise derelict requires a greater area proposed options land and industrial of land to be do not suggest premises. Permanent constructed (work sites, the demolition of land take related to the casting basin, etc.). any residential option will be minimal Although the properties or and confined to small environmental risks important areas of currently associated with community safeguarded land on landtake are anticipated facilities it is
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
both sides of the to be greater than the considered that Thames. Environmental bored tunnel, they will once operational risks associated with be of temporary the overall landtake and character. environmental subsequently land use risks will be the are not anticipated to be similar for both significant. ‘Base’ options.
Cultural The proposed bored No mitigation Given that the Consultation Given that the Heritage tunnelling works are measures immersed tunnel option, with English construction anticipated to be at required. when compared with Heritage and methodology of sufficient depths to the bored tunnel, further the immersed avoid impacting on requires a greater area archaeological tube tunnel is archaeological remains of land to be work will be likely to affect however the tunnel constructed, there is required to more heritage portals are likely to greater potential to assess the assets (including result in the removal of disturb archaeological potential in the River any archaeological remains within the impacts the Thames) it is remains situated within areas of archaeological option will have considered that the portal footprints. potential as designated on the by the London archaeological environmental
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
The archaeological Boroughs of Greenwich resources prior risks associated potential at this stage is and Newham. The to the with the unknown; therefore immersed tunnel will commencement Immersed Tube further archaeological also require a channel of construction. ‘Base’ option are assessment work may to be dredged in the Mitigation higher. be required at a later River Thames. This is measures such stage to confirm likely to remove any as impacts. archaeological archaeological resources located within watching briefs the Archaeological to be Priority Area designated undertaken by the London Borough during the of Newham which construction of extends to the centre of the scheme. the River Thames.
Ecology and Terrestrial Ecology Terrestrial Terrestrial Ecology Terrestrial Higher Nature Ecology Ecology environmental Conservation Whilst the tunnel portals The environmental risks risks are found will be constructed in Retain as much will be similar to the There would be with the areas of land that are as possible of bored ‘Base’ option, a greater immersed tube
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Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
largely urban and are the although there may be temporary loss ‘Base’ option due not particularly regarded scrub/woodland additional risks of habitat on the to dredging as ecologically sensitive, habitat within the associated with the foreshores and operations during the loss of the areas of Scheme. casting basin, the compensation construction and scrub/ grassland and location of which is measures (e.g. the vertical woodland habitat could In the case that unknown. creation of alignment of the be significant in a the habitat) may be immersed tube borough context given scrub/woodland Marine Ecology required. tunnel. In habitat cannot the shortage of such The construction of an addition, the habitat locally. be retained, Marine Ecology immersed tube consideration immersed tube tunnel will have an impact on Measures will ‘Base’ option will The area required for should be given require more the construction of the to incorporating the River Thames and need to be Tidal Tributaries SINC incorporated additional survey southern end of the similar habitat work and Scheme includes an types within the which supports some into the CEMP habitats of conservation to ensure that consultation with area of derelict land that design of the non-statutory appears to be heavily completed importance (e.g. there would be intertidal mudflats) and no significant consultees to overgrown with a Scheme. confirm the mixture of small trees ecological important impacts on biota (e.g. birds and aquatic habitats presence of and scrub. This is one of protected species the only patches of such fish). The potential associated with
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
habitat on the Marine Ecology environmental risks of sedimentation and identify Greenwich Peninsula, this will include: or pollution. appropriate and has been identified No mitigation mitigation. More on Natural England’s measures Temporary loss of The mitigation complex website as ‘deciduous required. intertidal mudflat habitat measures mitigation woodland’, a BAP and associated benthos associated with measures are habitat. All other areas from the construction of potential risks likely to be of green space within the immersed tunnel associated with required as more dredging are: this option appear to Temporary disturbance habitats are likely comprise landscape to intertidal mudflat and Spill control and to be affected by planting of limited nature associated benthos hence the immersed conservation value. resulting in temporary controlling tube tunnel. Marine Ecology disturbance to bird turbidity during The effect on the communities caused agitation river dynamics The bored ‘Base’ option through installation of dredging of due to the will involve tunnelling the cofferdams alluvium, bulk foreshore beneath the River dredging and cofferdams and Thames which is Temporary reduction in maintenance water quality as a result the dredged designated as the River dredging trench will require Thames & Tidal of an increase in suspended solids and Dredging during numerical
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
Tributaries SINC. Given release of contaminant winter season modelling to that the River Thames bound sediments to avoid fish accurately predict will not be directly causing temporary migrations the effect on affected by the effects in fish and other current flows and tunnelling, the Scheme biota during the Licensed determine the is likely only to result in dredging operations disposal of extent of erosion indirect effects on contaminated and deposition ecology within the River Temporary increase in materials and within the river. Thames from, for aquatic noise levels non- example, elevated noise during the installation of contaminated levels or the risk of the immersed tunnel materials. which could have accidental spillages Dredging work during construction. adverse effects on marine mammals and will need to be fish. licensed and comply with The construction of an criteria for immersed tunnel has turbidity and the potential to oxygen levels. significantly affect marine ecology from
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
dredging operations. Dredging may prevent adult fish from migrating upstream to possible spawning grounds and result in mortality in younger fish. In addition, mobilisation of contaminated sediments has the potential to cause some direct toxicological effects leading to impairment of physiological functions in fish. Combined effects of dredging, outfalls and development are likely to occur during the summer months of June
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
to August when dissolved oxygen levels are at their lowest.
The need to undertake construction works and dredging within the river to construct an immersed tunnel could result in the deterioration of water quality, elevated suspended sediments in the river and the loss of intertidal mudflats during construction and during operation if permanent structures are needed in the river.
Effects on All The key receptors will Mitigation The environmental risks In addition to On the whole the
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
Travellers be non-motorised users measures associated with the the mitigation environmental such as pedestrians and include: immersed tube ‘Base’ measures risks of the two cyclists and vehicle option are similar to proposed for tunnel options drivers for the view from The construction those identified with the the bored ‘Base’ are considered to the road and driver of a new bored ‘Base’ option. option, the be similar. More stress assessments. footbridge near immersion of receptors are The construction of the Boord Street The key receptors will the tunnel likely to be bored tunnel is likely to additionally include the elements will affected during Ensuring the river users. result in the followings Scheme design require the construction of environmental risks: makes Navigation issues are advanced the immersed appropriate anticipated on the River coordination tube tunnel Reduced amenity for the with Port of hence additional users of the cycle routes provision for Thames during pedestrian construction works. The London mitigation and footpaths in the Authority (PLA) measures may vicinity of the tunnel crossings when immersion of tunnel designing the elements will require to reduce the need to be portal Changes in the environmental implemented to pedestrian crossings new highway short term closure of arrangements at the river. risks associated reduce the that currently exist on with the environmental both sides of the river each of the tunnel portals Depending on the exact temporary risks with regards Increased severance on location of the closure of the to navigation. Minimising cofferdam basin, cycle
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
certain roads depending footpath and and pedestrian routes river. upon the traffic changes cycle route on the both sides of the diversions both river are likely to be Reduced drivers stress during affected. as a result of reduced construction and congestion and also those that enhanced road layout may be needed Improvements to public permanently transport connections during Scheme operation
Ensuring clear signage for non- motorised users
Ensuring the design of the Scheme reflects public transport needs.
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
Geology and Environmental risks Potential The immersed tube Same as for Although the Soils associated with the mitigation tunnel will be relatively bored ‘Base’ environmental bored ‘Base’ option measures will shallow and may option. risks and include: include: therefore pose a higher associated risk to disturb the mitigation Disturbance of Treatment of underlying measure are potentially contaminated contaminated contaminated soils. This considered to be land and areas of Made land based on could result in the essentially the Ground the information contamination of same for both obtained from Mobilising contaminants controlled waters such options, it is the site as groundwater within anticipated that in the soil that would investigation otherwise be immobile the Secondary aquifer the excavation Completion of and the River Thames. and disposal of Creation of new Risk Contamination could the shallow pollutant pathways for Assessments migrate horizontally and (potentially contamination to reach and a vertically along newly contaminated) groundwater and Remediation created preferential soil layers in surface water resources Strategy (if pathways such as close proximity to drainage runs, piles and the river Thames Creation of required) and site investigation with the contaminated run-off adherence to immersed tube
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
that could affect surface them throughout boreholes. ‘Base’ option will and groundwater the construction pose more risk of resources works The casting basin mobilising requirements of this contaminants Effects of the tunnel Adherence to option will result in a and creation of construction on ground the Construction greater amount of new pathways. stability Code of Practice excavation work near for the the River Thames The cut and cover Sustainable Use hence higher risk to sections are generally of Soils on create pollutant deeper for the bored Construction pathways. tunnel option than for Sites (Defra, the immersed tube 2009) option therefore the excavated material from Adherence to the deeper ground is Environment less likely to be Agency Pollution contaminated (apart Prevention from the ground break Guidelines point to place the TBM Use of a CEMP.
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
at Silvertown end).
Materials The following Optimise the The immersed tube Where re-use is The immersed environmental risks are design of the tunnel will generate not possible tube tunnel identified: Scheme to around 40% more there will be a generates reduce need for waste materials due to requirement to approximately Waste generated as a materials import earthworks excavations dispose of 40% more waste result of excavation and minimise of the casting basin and excavated material. The works waste (including excavation of the open material by earthworks Increased pressure on proactive cut and cover passages licensed excavations on waste management and engagement at the entrance and carriers to land for the disposal facilities with the design exits from the tunnel. licensed landfill immersed tube team to Waste material will also sites and ‘Base’ option Energy consumption encourage the arise from the dredged handled in include lengthy through plant use and selection of channel in which the accordance with cut and cover transportation of materials taking immersed tunnel will be the Waste tunnels at each materials and waste account of their constructed within the Management approach and the potential River Thames. For an Regulations. casting basin on- Release of environmental immersed tunnel there site will yield contaminants to air, land effects are large volumes of significant or water through the material arising and quantities of
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
sourcing, use, storage, A CEMP large volumes required River Terrace transportation and documenting for backfilling. The deposits and disposal of materials control dredged cohesive London Clay. and waste that could measures for the material will not be result in pollution use, storage and suitable for re-use as Limited mitigation transportation of backfill to the tunnel options are Flooding as a result of materials as well elements and will need available much of inappropriate materials as the storage to be disposed of. the waste and/or waste storage and Terrace gravels may be material may not transportation of re-usable but the be suitable to re- The excavated material use. from tunnelling activity wastes volumes are small and will predominately be the cost of storage on A Site Waste site and re-handling to removed from the site at Management which the TBM enters place the material as Plan that will backfill may be the ground and from the outline the types area of the cut and prohibitive. It is and quantities of therefore unlikely these cover and open cut wastes that portals located and the materials will be re- would be used. northern and southern generated and ends of the tunnel at how they would
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
Silvertown and the be reduced, re- Greenwich Peninsula used, managed respectively. and disposed of
Examine the potential re-use and disposal options for excavated material and in particular re-use options for London Clay.
Noise and The construction and Thin/low-noise Same as bored ‘Base’ Same as bored The Vibration operation of new tunnel surfacing can option. ‘Base’ option. environmental crossing has the reduce noise risks and potential to cause levels by up to mitigation increase in traffic noise 3.5dB (A) where measures on an existing road by the average associated with altering the traffic flow speed of the noise will be the
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
and composition. In the traffic is above same for both case of the bored tunnel 75 mph. Below options due to a completely new noise this speed there the same number source would be created is a reduced and location of which could have a benefit from a receptors and significant effect upon thin/low-noise same levels of the existing noise surface due to traffic flow. climate. vehicle engine noise The majority of contributing residential receptors more to the within the anticipated overall noise noise study area are level located on the northern side of the Scheme in The use of noise Canning Town. Road barriers can traffic noise on the reduce the noise southern side from the level at dwellings A102 and on the by reducing northern side from the sound A1011 and A13 would propagation. To
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
be the most likely be most sources of road traffic effective, noise. barriers are required to be either very close to the source (the road) or the receptor (the dwellings)
A reduction in the average speed of vehicles can result in a reduction in traffic noise.
Townscape and Given the surrounding Achieving This option has a Location of the The construction Visual townscape and that the finishes to potential for greater casting basin of the immersed majority of the crossing engineering visual impact during off-site. tube tunnel is
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
infrastructure would be structures that construction due to likely to result in below the ground, it is are appropriate larger construction area significant not anticipated any to townscape located on-site. temporary significant impacts to context and Receptors include users deterioration of occur outside the areas visual amenity of the Emirates Airline the existing of the portals. Cable Car and views. There will Appropriate residents on both sides be no significant landscaping of the river. difference between the Ensuring an appropriate ‘Base’ options lighting design. once the tunnel is operational.
Water Given the nature of the Where works are Construction of the In addition to When compared Environment works it less likely that undertaken in immersed tunnel will the mitigation with the bored the bored tunnel option close proximity require the localised measures ‘Base’ option, the will directly affect any to the flood demolition of the river proposed for proposed surface watercourses as defences along flood defence walls to the bored tunnel immersed tunnel no works are proposed the banks of allow the connection option and option has the within the River Thames either the River with the landside based on the potential to result Thames or the structures. Temporary experience on in significant
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
or the River Lea. River Lea cofferdams will need to the Emirates adverse effects consent from the be constructed to Airline Cable that require Potential environmental Environment maintain flood defences Car project, it is mitigation risks include increased Agency for during the works. In anticipated that measures and flood risk as a result of works affecting addition, there is also a scouring the approval of works in close proximity watercourses potential for detriment assessment will both the to, or the crossing of, and/or flood to the water quality of also be required Environment existing flood defences, defences will be groundwater and to assess the Agency and the the introduction of required prior to surface waterbodies impact of the Port of London impermeable surfaces undertaking the associated with heavily Scheme on Authority (PLA) and loss of floodplain works. silted, or otherwise water flow and prior to storage where the contaminated, runoff sediment commencing linking highway network Given the nature from construction sites. transport, works. The is constructed. In of the work and particularly hydrodynamic addition, there is also the size of the Given the need for around modelling is potential for detriment to site it is dredging and the Bugsby’s Reach important the water quality of anticipated that construction methods of which, because it will groundwater a formal flood the immersed tunnel according to the indicate whether waterbodies associated risk assessment within the River EA, is any additional with heavily silted, or will be Thames, it is susceptible to inter-tidal habitat otherwise contaminated, undertaken and anticipated that severe erosion loss is expected
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environmental Bored ‘Base’ option Immersed Tube ‘Base’ option Options topic Comparison Environmental Risks Mitigation Environmental Risks Mitigation Comments Measures Measures
runoff from construction approved by the environmental risks are (Mott as a result of sites. Existing river walls Environment likely to occur with MacDonald, erosion. The are primarily formed Agency. regards to changes to 2012). results of the from steel sheet piling water level, flow paths modelling should and there is a risk of and dynamics and the also confirm that encountering these movement of sediment erosion will not during bored tunnelling within the River. adversely affect works. the integrity of the flood defences if the bed level is reduced due to scouring. Where bed levels are lowered this can reduce the stability of the tidal defence retaining walls.
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Table 2 Options Comparison (‘Base’ options vs ‘Shortened’ options)
Environm ‘Base’ (long) options ‘Shortened’ options Options ental Comparison topic Environmental risks Mitigation Environmental risks Mitigation Comments measures measures
Air Quality The options have the The mitigation The environmental risks The mitigation There is no potential to result in measures will be are considered to be measures will be significant increase of traffic flows the same as similar as the ‘Base’ the same as difference between and hence change those listed in options as air quality will those listed in the two sets of emissions on the local Table 3.A-1. be affected by the same Table 3.A-1. options. The road network. There are levels of traffic flow with location of likely to be both all of the proposed sensitive receptors improvements in air options. with the quality and deterioration ‘shortened’ options in air quality at receptors As the location of the will be closer to the as a result of the change tunnel portals will be river Thames but it in traffic flows. moved closer to the is not considered River the concentration that this will affect of exhaust fumes in the more receptors areas immediately than those affected adjacent to the tunnel if the any of the portals is likely to affect ‘Base’ Options is users of the commercial taken forward. buildings located nearby.
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environm ‘Base’ (long) options ‘Shortened’ options Options ental Comparison topic Environmental risks Mitigation Environmental risks Mitigation Comments measures measures
Communit Permanent land take No mitigation More landtake will be No mitigation More receptors are y and related to the options will measures required with the measures likely to be Private be confined to areas of required. ‘Shortened’ options as required. affected by the Assets currently safeguarded the exit road on the open road section land on both sides of the south side of the River on the south side Thames. Impacts on land runs above ground rather of the river. take and subsequently than in a cut-and-cover Although it is land use are anticipated tunnel. unlikely that any to be with regards to compensation worksites and casting In addition, measures will be basin (for immersed tube environmental risks required with option) and temporary associated with noise regards to land-take for the cut and pollution are likely to landtake at this cover sections on both occur in the open road design stage of the sides of the River with section on the south side Scheme, both ‘Base’ options. of the River affecting consideration receptors in the should be given to residential development the fact that more immediately adjacent to permanent Millennium Way road. landtake will be
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environm ‘Base’ (long) options ‘Shortened’ options Options ental Comparison topic Environmental risks Mitigation Environmental risks Mitigation Comments measures measures
required with the ‘Shortened’ options.
Cultural The environmental risks and associated mitigation measures of options B and C No significant Heritage (‘Shortened’) are unlikely to be significantly different from those of the ‘Base ‘options difference. described in Table 3.A-1.
Ecology The environmental risks and associated mitigation measures of options B and C No significant and (‘Shortened’) are unlikely to be significantly different from those of the ‘Base’ options difference. Nature described in Table 3.A-1. Conservat ion
Effects on The construction of the The mitigation In addition to the Severance of Although the All long tunnel options is measures will be environmental risks east-west construction of Travellers likely to result in the the same as identified with the ‘Base’ movements on new pedestrian following environmental those listed in options, increased the south side of bridge at Edmund risks: Table 3.A-1. severance is likely to the river will be Halley Way will occur in the northern part slightly alleviate the Changes in the multiple of the Greenwich alleviated with a severance issues pedestrian crossings that Peninsula for west-east new pedestrian on the south side
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Silvertown Tunnel
Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environm ‘Base’ (long) options ‘Shortened’ options Options ental Comparison topic Environmental risks Mitigation Environmental risks Mitigation Comments measures measures
currently exist on both movements. bridge in the of the River, the sides of the river area of Edmund overall severance Halley Way (see in the area will be Increased severance on Options B and C will Drawing MMD- worse as the open certain roads depending 298348-C-DR- cut road will be a upon the traffic changes. allow more open views from the road as the cut 00-ZZ- barrier to Reduced drivers stress and cover section on the 1060_P1). movement for non- as a result of reduced south side of the river will motorised users in congestion and be reduced. the northern part of enhanced road layout the peninsula.
Reduced amenity for the users of the cycle routes and footpaths in the vicinity of the tunnel portal.
Geology The environmental risks and associated mitigation measures of options B and C No significant and Soils (‘Shortened’) are unlikely to be significantly different from those of the ‘Base’ options difference. described in Table 3.A-1.
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environm ‘Base’ (long) options ‘Shortened’ options Options ental Comparison topic Environmental risks Mitigation Environmental risks Mitigation Comments measures measures
Materials The environmental risks and associated mitigation measures of options B and C No significant (‘Shortened’) are unlikely to be significantly different from those of the ‘Base’ options difference. described in Table 3.A-1.
Noise and The ‘Base’ options have Measures to Environmental risks will Measures to More receptors are Vibration the potential to cause an minimise be associated with minimise likely to be increase in traffic noise environmental increased traffic noise environmental affected with the on an existing road by risks will be from the open road on risks will be ‘Shortened’ B and altering the traffic flow required (e.g. the approach to the required (e.g. C options including and composition. thin/low-noise tunnel in the south thin/low-noise some key sensitive surfacing, noise section of the Scheme. surfacing, noise receptors located barriers, The Greenwich barriers, to the east of the reduction in the Peninsula Masterplan reduction in the Scheme. Mitigation average speed envisages residential average speed measures will be of vehicles, etc.) development northeast of vehicles, etc.) essentially the of Millennium Way Road same, but noise which currently is barriers will be anticipated to comprises located in slightly of 18 residential different areas buildings (Class 2 and/or (closer to the key 3). In addition, key sensitive
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Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
Environm ‘Base’ (long) options ‘Shortened’ options Options ental Comparison topic Environmental risks Mitigation Environmental risks Mitigation Comments measures measures
sensitive receptors likely receptors). to be affected by the increased traffic noise levels are identified 0.5miles south of the proposed tunnel approach road at Millennium Primary School (see Drawing 6-2 – UA005651- UE31D)
Townscap The construction of the Potential The raised level of the Potential The ‘Shortened’ e and immersed tube tunnel is mitigation open road on the south mitigation options B and C Visual likely to result in measures during side of the River Thames measures are likely to significant temporary construction of has the potential to include: negatively affect a deterioration of the the immersed permanently deteriorate wider variety of existing views. There will tube tunnel will the existing views Achieving receptors be no significant visual be locating the affecting a number of finishes to particularly on the impact once the tunnel is casting basin receptors. The cut and engineering south side of the operational. off-site. cover section will be structures that River Thames. reduced and the are appropriate More complex
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Silvertown Tunnel Appendix 3.A Options Summary Table Document Reference: 6.3.3.1
Environm ‘Base’ (long) options ‘Shortened’ options Options ental Comparison topic Environmental risks Mitigation Environmental risks Mitigation Comments measures measures
approach road to the to townscape mitigation tunnel as well as context and measures will be associated infrastructure visual amenity required to will be visible to users of address some the Emirates Airline Appropriate permanent visual Cable Car, visitors of the landscaping impacts related to commercials buildings the ‘Shortened’ and leisure facilities and tunnel options. residents on both sides of the new road.
Water The environmental risks and associated mitigation measures of options B and C On the whole there Environm (‘Shortened’) are unlikely to be significantly different from those of the ‘Base’ options is no significant ent described in Table 3.A-1. Flood/drainage issues associated with reducing the level of difference between Millennium Way Road with the ‘Shortened’ and C options are anticipated, but these can be the two sets of mitigated through careful design. tunnel options.
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Appendix 3.A Options Summary Table
Document Reference: 6.3.3.1
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