Hinkley Point C Connection Project Requirement 5 (4) Construction Traffic Management Plan (CTMP) Addendum

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National Grid Unit 6 The Grange Business Park Wick Road Hewish Somerset BS24 6RR

25 May 2021

Table of Contents

1 INTRODUCTION ...... 5 1.1 This document ...... 5 1.2 Overview of the Project ...... 6 1.3 Consultation ...... 7 1.4 Response to pre-application comments ...... 7 2 PROPOSED UPDATES ...... 13 2.1 Overview of proposed updates ...... 13 2.2 Stage 7.2 and Stage 10.1: access required for dismantling works ...... 20 3 ASSESSMENT ...... 24 3.1 Overview ...... 24 3.2 Use of Whitehouse Lane for access to and from the B3128/Clevedon Road . 24 3.3 Use of additional access route to Seabank Substation ...... 26 3.4 Use of Cannington Bypass ...... 28 3.5 Use of existing access route to Portishead Substation ...... 29 3.6 Stage 10.1 additional access routes ...... 31 3.7 Access required for dismantling works ...... 36 3.8 Consideration of cumulative impacts ...... 40 APPENDIX A. PLANS ...... 43

Abbreviations and Glossary

Abbreviation Definition BCC Bristol City Council CTMP Construction Traffic Management Plan DCO National Grid (Hinkley Point C Connection Project) Development Consent Order – S.I. 2017 No 786 HGV Heavy Goods Vehicle HPC Hinkley Point C New Nuclear Power Station LGV Light Goods Vehicle LHA Local Highway Authority LPA Local Planning Authority NSC North Somerset Council SCC Somerset County Council SDC Sedgemoor District Council SGC South Gloucestershire Council SWTC Somerset West and Taunton Council WPD Western Power Distribution

Term Definition Construction “CEMP” means the Construction Environmental Management Plan Environmental (Document 5.26.1C) together with the Archaeological Written Management Plan Scheme of Investigation (Document 5.26.4C), the Biodiversity (CEMP) Mitigation Strategy (Document 5.26.3C) the Construction Traffic Management Plan (Document 5.26.5C), the Noise and Vibration Management Plan (Document 5.26.7B), the Public Rights of Way Management Plan (Document 5.26.6C) and the Waste Management Plan (Document 5.26.2C) which incorporates the findings and recommendations of the Environmental Statement, certified under article 44 (certification of plans etc.

Limits of Deviation “limits of deviation” means the limits of deviation referred to in article 5 (limits of deviation) of the DCO and shown on the Works Plans.

Relevant Local “relevant local authority” means, in any given provision of the DCO, Authority the local authority for the area to which the provision relates.

Relevant Local “relevant highway authority” means, in any given provision of the Highway Authority DCO, the local highway authority for the area to which the provision relates. Relevant Local “relevant planning authority” means, in any given provision of the Planning Authority DCO, the local planning authority for the area to which the provision relates.

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1 INTRODUCTION

1.1 This document 1.1.1 Following grant of The National Grid (Hinkley Point C Connection Project) Order 2016 (as amended) (‘the DCO’), the works on construction of the authorised development have commenced. Access routes for construction vehicles must comply with those specified within the Construction Traffic Management Plan (CTMP), which forms Appendix 4 of the Construction Environmental Management Plan (CEMP). 1.1.2 The CEMP is secured by Requirement 5 of the DCO: 5.—(1) All construction works for the authorised development and mitigation works to minimise the impacts of construction must be carried out in accordance with the CEMP, unless otherwise agreed with the relevant planning authority and the relevant highway authority as may be appropriate to the relevant plan, scheme or strategy concerned. (2) The CEMP, which specifies measures to be used to minimise the impacts of construction works, incorporates the following plans, scheme and strategy— ….. (d) Construction Traffic Management Plan; … (3) Any works carried out pursuant to the plans, scheme and strategy referred to sub-paragraph (2) must be carried out in accordance with the approved plan, scheme or strategy unless otherwise agreed with the relevant planning authority. (4) The plans, scheme and strategy referred to in sub-paragraph (2) must be implemented as approved unless otherwise agreed with the relevant planning authority and the relevant highway authority as may be appropriate to the relevant plan, scheme or strategy concerned. 1.1.3 Requirement 5(4) envisages and allows for updates to the CTMP to made, providing approval from the relevant planning authority is forthcoming, without a ‘change’ to the DCO being required. 1.1.4 This document proposes updates to the CTMP in the form of an addendum. The updates in relation to prescribed construction traffic routes specified within Appendix C of the CTMP. 1.1.5 The proposed updates to the construction traffic routes are detailed in Section 2.2 of the CTMP Addendum and are structured around the Stages of the project1. In summary, the proposed updates to construction traffic routes are: • Stage 3.1 and Stage 12: access to Seabank Substation; • Stage 4: access from Junction 20 of the M5; • Stage 4 and Stage 9: access to Portishead Substation; • Stage 4 and Stage 10: access through Whitehouse Lane;

1 Stages of the Project as defined in the Written scheme of stages document, approved by the relevant planning authorities pursuant to Requirement 4 of the DCO.

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• Stage 7.2 and Stage 10.1: access for dismantling of existing overhead lines; • Stage 10: access to 400kV overhead line pylons; • Stage 10: Royal Portbury Dock Road; • Stage 10: Gordano Way / Marsh Lane; • Stage 10: Kings Weston Lane; • Stage 10: Moorhouse Lane; • Stage 11: use of Cannington bypass; and, • Stage 11: access to Shurton Line Entries. 1.1.6 The information submitted within this CTMP Addendum document demonstrates that the updates sought can be achieved through an addendum to the CTMP, and there is nothing to trigger a further round of statutory consultation. An assessment of each update is included within the CTMP Addendum to demonstrate that no materially new or materially different environmental effects from those assessed in the Environmental Statement accompanying the DCO would arise as a result of the updates. 1.1.7 It should be noted that this document sits alongside the existing CTMP and does not replace it (with the exception of the construction route plans, which supersede those included within the original CTMP). All existing mitigation measures set out within the CTMP remain relevant. 1.1.8 This document has been submitted for approval to Bristol City Council, North Somerset Council, Sedgemoor District Council, Somerset West and Taunton Council and South Gloucestershire Council as the relevant planning authorities associated with the authorised development for the discharge of Schedule 3 Requirement 5 of the DCO. 1.1.9 Whilst not a determining body for the application, a pre-application version of the CTMP Addendum was provided to Somerset County Council (as relevant highway authority for Sedgemoor and Somerset West). Comments made by SCC as part of the pre-application consultation have been considered in preparing this submission.

1.2 Overview of the Project 1.2.1 National Grid gained development consent from the Secretary of State for Energy and Climate Change for the Project on 19th January 2016. The DCO provides powers to National Grid for the authorised development, and powers to Western Power Distribution (WPD) for the WPD works. The Project comprises a new 400,000 volt (400kV) electricity transmission connection between Bridgwater, Somerset and Seabank Substation, north of Avonmouth together with associated development. 1.2.2 The Project falls within the administrative boundaries of Bristol City Council, North Somerset Council, Sedgemoor District Council, Somerset County Council, Somerset West and Taunton Council and South Gloucestershire Council. 1.2.3 The Project comprises the following elements:

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• Construction of a 57km 400kV electricity transmission connection between Bridgwater in Somerset and Seabank, near Avonmouth, comprising: o Installation of a 400kV overhead line. o Installation of 400kV underground cables. • Modifications to existing overhead lines at Hinkley Point, Somerset. • Construction of three 400kV Cable Sealing End (CSE) compounds along the route of the connection. • Construction of a 400/132kV substation at Sandford, North Somerset. • Extension of the existing 400kV substation at Seabank. • The removal of existing 132kV overhead lines and the construction of replacement 132kV overhead lines and 132kV underground cables. • Extensions/modifications to existing 132kV substations at Churchill, Portishead, Avonmouth and Seabank. • Associated works, for example, temporary access roads, and highway works temporary construction compounds, scaffolds, work sites and ancillary works.

1.3 Consultation 1.3.1 This document proposes updates to the Construction Traffic Management Plan (Document 5.26.5C) in the form of an addendum. 1.3.2 At the National Grid and Joint Officers Group Meeting on 30th July 2020, it was agreed that National Grid would seek formal agreement for updates associated with construction traffic through a submission pursuant of Requirement 5 (4). It was agreed that these updates would be proposed in the form of a CTMP Addendum and the submission would be made to the relevant planning authorities for the project. 1.3.3 Prior to the formal submission of this document for approval under Requirement 5 (4), National Grid presented the proposed updates to the relevant highway authorities for the project at the Traffic Management Group (TMG) meeting on 16th September 2020. The general approach to the CTMP Addendum was considered to be appropriate by the TMG. 1.3.4 A draft version of the document (Doc SW 5D A) was also shared for pre- application consultation with the relevant planning authorities, who consulted with the relevant highway authorities in October 2020.

1.4 Response to pre-application comments 1.4.1 The comments raised through the pre-application consultation, and how these have been taken into account in the updated version of the document issued for submission (this document) are provided in Table 1-1. 1.4.2 The pre-application version of the document included a proposed update relating to the ‘This is Gravity’ development in Sedgemoor District Council (Somerset County Council as local highway authority). This update is no longer currently

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being considered by National Grid, and as such the proposed update has been removed from this version of the CTMP Addendum. Although comments were received on this proposed update as part of the pre-application consultation, these comments have been omitted from Table 1-1 as they are no longer relevant.

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Table 1-1 Pre-application Consultation Comments (on Doc SW 5D A)

Topic Consultee Comments received Response

General North Somerset A thorough and robust assessment of the proposed addendum must be More detailed evidence of the forecast Council and undertaken by the applicant and in turn by the Joint Councils. For this to usage of each of the proposed amended Sedgemoor be done, greater evidence and assessment of the addendums must be routes and an assessment of the District Council provided. impacts thereof is provided in Section 3.

General Bristol City No comments received at the time of writing this report. Noted. Council Highways

General South In looking at this pre-app for addendum to the CTMP I note that there is Noted. Gloucestershire little impact on South Gloucestershire Council in particular the local Council highway network. As such there would be no Transportation DC objection Highways to the amendments.

General Somerset County Para 1.1.5 sets out that “This document has been submitted for approval Noted. Paragraph updated accordingly. Council to Bristol City Council, North Somerset Council, Sedgemoor District Highways Council, Somerset West and Taunton Council and South Gloucestershire Council as the relevant planning authority and Somerset County Council as the highway authority for the authorised development and for the discharge of Schedule 3 Requirement 5 of the DCO.” Please note that we have not received the addendum as a determining authority but as a consultee. We would therefore advise that this paragraph is updated accordingly.

Stage 3.1 and Stage North Somerset This element of the addendum to the CTMP is therefore likely to be Noted and amendment made. 12: access to Council and acceptable. However, it is recommended that the applicant recast and Seabank Substation Sedgemoor represent this change as an ‘amendment’ rather than an ‘implicit change’. District Council

Stage 4 and Stage North Somerset ‘Whilst the route may be the only option, no information has been provided Further detail on the anticipated levels of 9: access to Council and to detail the nature or volume of traffic so that an assessment of potential construction traffic utilising the route and

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Topic Consultee Comments received Response

Portishead Sedgemoor impacts can be made. It is recommended that such information is provided an assessment thereof is provided in Substation District Council and that an assessment of this is made by the applicant so that in turn it Section 3.5. Please note, subsequent to can be reviewed by the Joint Councils. At this stage it would be premature the pre-application consultation, to confirm the addendum required is immaterial.’ National Grid have also identified a further need to access Portishead Substation as part of the Stage 10 works. This is also addressed within Section 3.5.

Stage 4 and Stage North Somerset The need for large vehicle/AIL access to the existing substation through Noted. 9: access to Council the Ashlands development site in Portishead was allowed for in the design Portishead Highways of the road layout along Phoenix Way, Stonechat Green and The Finches. Substation The route was considered and approved within the planning process for the site. It is the retained prescribed route to the Sub-Substation.

Stage 4: access North Somerset The high-level environmental review that has been undertaken provides Additional information has been through Whitehouse Council and no clarity on the duration for which the alternative route would be used, no provided within Section 3.2. Lane Sedgemoor detail on the nature of vehicles or quantum. For the purposes of this District Council assessment it has been assumed it is simply a diversion of traffic that would have otherwise used Cuckoo Lane only as set out in the DCO ES Transport Assessment. For any robust assessment and conclusion to be drawn on whether this element of the addendum is likely to give rise to any materially new or materially different environmental effects from those assessed in the Environmental Statement more detail must be provided by the applicant. Consideration should be given to factors such as, the actual number of properties potentially effected, duration of use, positive and negative effects, proximity of those properties to the route etc.

Stage 4: access North Somerset The proposal for construction traffic accessing and exiting from the Noted. through Whitehouse Council National Grid bellmouth on Whitehouse Lane directly to/from the B3128 Lane Highways Clevedon Road before re-joining the approved construction traffic route (so as not to use Cuckoo Lane) was reviewed early in 2020 and considered acceptable as it would avoid possible conflicts with construction traffic meeting up in Cuckoo Lane.

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Topic Consultee Comments received Response

The draft Doc SW 5A and associated plans have been reviewed by the Highway Authority and are considered to be acceptable.

Stage 7.2 and Stage North Somerset The dismantling of the existing 132kV lines where forming part of the DCO Additional information has been 10.1: access for Council and authorised works (as set out in Schedule 1 of the DCO) should utilise the provided within Section 2.2 and Section dismantling of Sedgemoor CTMP prescribed routes and haul roads. If there is an intention for this 3.7. existing overhead District Council element of the construction traffic to use alternative routes, then this needs lines to be presented more clearly and will need full assessment for the Joint Councils to consider. To simply say that the works associated with the dismantling will not exceed 10% of daily flows is not sufficient.

Stage 10: access to North Somerset This number of movements, spread across the 4 year period of the works Noted. 400kV overhead line Council and for Stage 10, albeit there will be peaks and troughs of movement is pylons Sedgemoor assessed to be immaterial given the commercial nature of the area and District Council lack of sensitive receptors. On the basis of the information provided, the update to the CTMP, to reflect the addition of Third Way to the prescribed routes, is assessed to be immaterial and unlikely to give rise to any materially new or materially different environmental effects from those assessed in the Environmental Statement. This element of the addendum to the CTMP is likely to be acceptable.

Stage 11: use of Somerset County I wouldn’t agree that commentary provided on this change within Table 2.1 The use of Cannington Bypass has been Cannington bypass Council clearly indicates that use of the Cannington Bypass was implicit within the recast as an amendment with Section 2. Highways DCO. Whilst I do agree that on face value routing via the bypass rather Further detail on the anticipated levels of than through the village of Cannington could have positive impacts, in construction traffic utilising the route and terms of the assessment, we need to understand firstly if it was assessed an assessment thereof is provided in in the DCO (and if it was, a clear reference should be provided); and Section 3.4. secondly, if it wasn’t assessed, we need to understand the impacts of using this route.

Stage 11: use of North Somerset Consideration must be given to the likely changes, both positive and Further detail on the anticipated levels of Cannington bypass Council and negative to assess whether use of the bypass is likely to give rise to any construction traffic utilising the route and Sedgemoor materially new or materially different environmental effects from those an assessment thereof is provided in District Council assessed in the Environmental Statement. These views are supported by Section 3.4. SCC Highways Officers. This element of the addendum to the CTMP

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Topic Consultee Comments received Response

requires further information and assessment before any conclusion can be drawn, if such an assessment was undertaken as part of the original environmental statement, evidence of this should be provided.

Stage 11: Access to North Somerset ‘The use of the very short lengths of public highway to access the Noted. the Shurton line Council and substation at Shurton is assessed to be immaterial and unlikely to give rise Entries for Stage 11 Sedgemoor to any materially new or materially different environmental effects from District Council those assessed in the Environmental Statement. This view is supported by SCC Highways Officers. This element of the addendum to the CTMP is likely to be acceptable.’

Stage 11: access to Somerset County Table 2.1 sets out updates which National Grid consider to be implicit Noted. Shurton Line Entries Council within the DCO. Shurton line entries is included, as this is only a small Highways section of road, which passes no residential properties, and no additional construction is required, we agree with the comments set out in the WYG draft report.

Consideration of North Somerset At this juncture it is considered that insufficient information and evidence Additional consideration has been given Cumulative Updates Council and has been provided by the applicant to the Joint Councils to be able to allow to the cumulative impacts of the Sedgemoor a robust assessment as to whether cumulatively the proposed changes to proposed updates in Section 3.8. District Council the CTMP are likely to give rise to any materially new or materially different environmental effects from those assessed in the Environmental Statement

Caswell Hill North Somerset The proposed amendment to remove the use of Caswell Hill for Noted. Council construction traffic between BM08 and BM09 is welcomed and has been Highways approved.

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2 PROPOSED UPDATES

2.1 Overview of proposed updates 2.1.1 Following the commencement of construction activity, instances have been found where access routes which have not been identified within the CTMP as a ‘prescribed’ route are required to facilitate construction of the authorised development. 2.1.2 A distinction has been made between those instances which are considered to be implicit in the approved DCO (see Table 3-1) and those instances which are proposed amendments to the CTMP (see Table 3-2). 2.1.3 Those entries in Table 2-1 have been scoped out from further assessment, as it is clear that their likely significant impacts are either minimal, or obviously within the previously assessed and approved parameters. 2.1.4 Entries in Table 2-2 are followed by further consideration demonstrating that the likely significant environmental effects arising from the updates are within those assessed by the original Environmental Statement. 2.1.5 Table 2-1 and Table 2-2 provide an overview of the proposed updates. Plans showing the proposed updates are provided within Appendix A. 2.1.6 Section 2.2 of the document provides details on the proposed updates for Stage 7.2 and Stage 10.1, relating to access for dismantling of existing overhead lines.

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Table 2-1 Proposed Updates to the Construction Traffic Management Plan

Stage Proposed update Reason for update Reason for scoping out Appendix of further assessment reference

Stage 4 Construction access to the following Prior to determination by the Secretary In light of the omission Appendix A bellmouths will be from Junction 20 of the M5 of State, as part of the application for within Table 7.1 of the Sheet 12 as opposed to Junction 19 of the M5 and the development consent National Grid Transport Assessment Portbury Hundred (as stated in the CTMP presented two line routeing options (Doc 5.22.1) (and by (Doc 5.25.5C)): (Option A and Option B). Proposed association Table 4.1 of construction routes providing access the CTMP (Doc • W-Route-BM07 to each option were assessed in the 5.26.5C)), it is considered • W-Route-BM08 Transport Assessment. The Secretary that accessing the • W-Route-BM09 of State subsequently approved bellmouths from Junction • C-LD92-BM01 Option B. By approving Option B, the 20 of the M5 would be • W-Route-BM10 opportunity to construct bellmouth C- compliant with the LDA95A-BM02 providing access from intended route within the Construction access to these bellmouths from the Portbury Hundred and an CTMP (Doc 5.26.5C) as Junction 20 of the M5 would make use of the associated section of haul road has required under haul road south of the M5 associated with the been removed and this land now lies Requirement 5 W-Route instead of Caswell Hill. As such, the outside the Order Limits. Thus the (Construction proposed construction route along Caswell ability to access bellmouths to the Environmental Hill from W-Route-BM09 to W-Route-BM08 south of C-LDA95A-BM02 no longer Management Plan). will no longer be required. This has been exists. reflected with an update to Appendix A Sheet Access from Junction 20 11. The Transport Assessment (Doc is also in accordance with 5.22.1) modelled trip distribution the CTMP plan The haul road associated with pylons LD95 – based on grouping the bellmouth “Construction Routes and LD98 is no longer required as ‘Option B’ for locations in association with proposed Bellmouth Location Plans the 400kV Overhead Line has been taken construction routes. To assess peak Sheet 11 of 12” (Doc forward which means that the pylons traffic impacts, the bellmouths listed 5.26.5C) which provides appropriate highway and associated with ‘Option A’ (LD95 – LD105) were grouped as ‘Group 15’ and haul road access to and are no longer proposed. The removal of this assessed as being accessed from the from the bellmouths. haul road has also been reflected with an M5 Junction 20 and the M5 Junction update to Appendix A Sheet 11. 19. The Environmental Statement Transport Assessment Sensitivity Test Appendices A to C (Doc 5.29.2.2.2) also assesses Group 15 as being

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Stage Proposed update Reason for update Reason for scoping out Appendix of further assessment reference

accessed from both M5 Junctions 19 and 20.

An omission arises in the Transport Assessment (Doc 5.22.1) Table 7.1 Breakdown of the proposed Routeing Strategy and the CTMP (Doc 5.25.5C) Table 4.1 Bellmouth Locations. The table in the CTMP is a direct copy of that in the Transport Assessment. The table notes that access to these bellmouths will be accessed from Junction 19 of the M5 and off the Portbury Hundred. This table misses off the option for Group 15 to also be accessed from Junction 20 of the M5 as was assessed which allowed for the scenario of Option A not being selected by the Secretary of State.

As described above, access off the Portbury Hundred and the associated haul road is no longer available to National Grid as this was not approved under Option B.

Stage 4 and Stage 9 Access to Portishead substation. While Portishead substation is marked Portishead substation is Appendix A in Annex C of the CTMP, no access existing infrastructure with Sheet 12 route is shown. The CTMP prescribes existing rights of access. routes to new bellmouths only and This access has been does not include access to existing maintained even with the infrastructure. construction of the adjacent housing estate, This distinction may have been with a route retained for intentional at the time of the drafting of large vehicles. As this is

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Stage Proposed update Reason for update Reason for scoping out Appendix of further assessment reference

the CTMP, but it permits confusion. the only route to the This update confirms access rights for substation, it is considered the avoidance of doubt. that this is implicit within the DCO. Portishead substation needs to be accessed for various stages of the It is considered that the Project. The access will be along the level of additional vehicle route already used to access the traffic requiring access to substation. access the substation for the project is not material. It is expected that there will be up to 15 HGV deliveries, and up to 15 people on site, each day when the substation works are at their peak.

Stage 10 Access to new 400 kV overhead line pylons Third Way is not identified in the Given the location of the Appendix A (LD 116 and LD117) via Third Way. Vehicles CTMP as a prescribed route. At the pylons, it is considered to Sheet 13 will access Third Way from either St Andrew’s time of submission, this road was not be implicit that this road Road or Avonmouth Way (both prescribed included as a new bellmouth was not would be required to routes) and will travel either east or west required, and it was considered to be access the tower location. along Third Way. implicit that this road would be used to access the tower location. Vehicles will use an Vehicles will use this route between Q2 2021 existing road which is and Q3 2025. Access to LD 116 will be via the The Road will be used by vehicles currently used by construction compound previously occupied accessing LD116 and LD117 during commercial/ industrial by Kings Heavy Haulage, and access to LD construction. HGVs. The road is of 117 will be accessed via a service road off minimal length with no Third Way. sensitive receptors along it. Receptors along Third Over the full duration of use, a total of Way are commercial and approximately 760 vehicles will enter the site, industrial in nature. and then exit the site using this road, resulting in approximately 1520 vehicle movements in total.

Stage 11 Access to Shurton Line Entries. The construction route as set out in The new substation at Appendix A Annex C of the CTMP does not Shurton is consented by Sheet 1 include a complete access route to the Hinkley Point C New

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Stage Proposed update Reason for update Reason for scoping out Appendix of further assessment reference

Shurton substation, only to the nearest Nuclear Power station bellmouth on Wick Moor Drove (JP1- DCO, which includes BM01). necessary access rights.

New roads associated with the Hinkley It should also be noted Point C development have since been that much of the additional built which form an access to Shurton routing is within the substation, and negate the need to Hinkley Point C Power construct the bellmouth JP1-BM01 on Station site, so the the west of Wick Moor Drove. Access distance of public highway through the Hinkley Point C site is affected is minimal. proposed using both of the new roundabouts on Wick Moor Drove, subject to agreement with EDF Energy. Additional temporary access from Wick Moor Drove to enable the erection/dismantling of scaffolding is to be taken through existing farm accesses on Wick Moor Drove (on the prescribed access route). Approvals for any works to these temporary accesses will be sought separately through the discharge of an application against Requirement 22 of the DCO.

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Table 2-2 Proposed Updates to the Construction Traffic Management Plan (New updates)

Stage Proposed update Reason for update Appendix reference

Stage 3.1 Use of additional access route to The additional access route is a separate, existing access route to the substation and Appendix A and Stage Seabank Substation. would enable construction traffic associated with Stages 3.1 and 12 of the authorised Sheet 13 12 development. The primary reason for this update is that the DCO-approved access route to the substation (which utilises the haul road through Crooks Marsh) would require significant ground works and would disturb the existing underlying contaminated material at Crooks Marsh.

The use of this access route is not prescribed in Annex C of the approved CTMP.

Stage 4 Use of Whitehouse Lane instead of Cuckoo Lane is subject to a 7.5T weight limit that commences at its junction with Appendix A and Stage Cuckoo Lane for construction traffic Clevedon Road/B3128. The restriction was introduced in June 2000 to prevent HGV Sheet 11-12 10 associated with the ‘W’ route for traffic travelling between the B3124 (Portishead) and the B3128 (Wraxall). The restriction access to and from the has an environmental purpose (not a structural purpose). Under the existing Weight Limit B3128/Clevedon Road. Order, National Grid has legal rights to access the bellmouths in Cuckoo Lane and Whitehouse Lane within the section covered under the weight limit.

Prior to the commencement of construction activity, Cuckoo Lane was deemed to be unsuitable for construction traffic due to its narrow width. Engagement with North Somerset Council took place between February and March 2020. It was informally agreed that construction traffic would use Whitehouse Lane rather than Cuckoo Lane.

The use of Whitehouse Lane is not prescribed in Annex C of the approved CTMP.

Please note, Cuckoo Lane will however be retained as a prescribed route for traffic associated with the dismantling of parts of the existing 132kV overhead line, as set out in Section 2.2. Two towers are situated in land directly adjacent to Cuckoo Lane which require access via Cuckoo Lane to enable their dismantling and that of the overhead line.

Stage 10.1 Royal Portbury Dock Road Royal Portbury Dock Road is a proposed extension to the prescribed route to gain access Appendix A through Bristol Port via its private service road network, as the alternative prescribed Sheet 12 route is unrepresentative of actual site conditions. Access has been agreed with Royal Portbury Docks and the Port Police to utilise the service road network of the port, which is well suited to HGVs and would not impact upon the general public.

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Stage Proposed update Reason for update Appendix reference

Stage 10.1 Gordano Way / Marsh Lane A minor extension to the prescribed route is required utilising Gordano Way / Marsh Lane, Appendix A as the alternative prescribed route is unrepresentative of actual site conditions. The route Sheet 13 is within an industrial / commercial area heavily trafficked by HGVs.

Stage 10.1 Kings Weston Lane An extension to the prescribed route along Kings Weston Lane is proposed to enable Appendix A access through the Wessex Water Sewage Treatment Works, as the prescribed route is Sheet 13 not deemed suitable following the identification of three large above ground sewer mains. The extension would utilise a short additional section of public highway before entering the private service roads within the Wessex Water site, which has been agreed with Wessex Water.

Stage 10.1 Moorhouse Lane Severn Road / Moorhouse Lane is required as a temporary access route to Henbury Loop Appendix A railway line, over which scaffold fall protection must be installed during construction of the Sheet 13 Stage 10.1 new build work, which will then be dismantled upon the completion of this section of the overhead line. No suitable alternative access to the railway is available.

Stage 11 Use of Cannington bypass for Cannington bypass was constructed after the DCO was granted for Hinkley Point C Appendix A construction traffic associated with Connection. This route would provide a more suitable access route as it would direct Sheet 2 Stage 11 rather than access through construction traffic around Cannington rather than through the town. Cannington. The use of the bypass is not prescribed in Annex C of the approved CTMP, which permits traffic through the town.

It is expected that there will be up to 28 HGV and 28 LGV two-way movements each day when the works are operative.

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2.2 Stage 7.2 and Stage 10.1: access required for dismantling works 2.2.1 In addition to the routes detailed within Table 2-1 and Table 2-2, there is a requirement to access existing 132kV overhead lines for dismantling through Stages 7.2 and 10.1. Stage 7.2 represents the dismantling of the F Route (south), whilst Stage 10.1 represents the dismantling of the F Route (north), W Route as well as short sections of the N Route, G Route and AT Route. 2.2.2 The removal of the existing 132kV overhead line will be carried out once the various sections of the overhead line has been disconnected from the WPD network. The conductors will be lowered to the ground, cut into smaller sections and gathered for recycling. The conductors will be placed on the ground exactly below where they currently sit on the towers. A reel-winder (large winch) will then be connected to the conductors and begin to recover the conductors, allowing for the wire to be wrapped onto a drum. This will be completed in multiple sections as the reel-winder is only capable of recovering approximately 1000m at a time, (which is approximately 3 to 4 spans). Where conductors pass over existing transport infrastructure (roads, railways, footpaths etc.), or existing properties, scaffold crash decks will be installed prior to the recovery of any conductors. 2.2.3 Where the conductors cannot be placed on the ground below and scaffolding is not feasible, the conductors will be supported by an additional Catenary Bond whilst in position on the towers. 2.2.4 There are two methods for pylon removal. The first method, which will be used on the majority of pylons, is felling. A winch bond will be applied to the tower top to hold it in place whilst the bottom of the tower legs are cut. This will leave a hinge section which enables the tower to fall in a planned direction. The second method involves the use of a crane to lift the tower out of position. The crane will lower the tower to the ground for dismantling a section at a time. 2.2.5 Unless a crane is required, vehicles used in the dismantling will be lightweight vehicles, such as tractor units. 2.2.6 Access to the existing 132kV overhead line will be via haul roads where possible. Dependant on ground conditions, where required, trackway panels may also be used to access the line. 2.2.7 As existing infrastructure, the towers already benefit from access rights for the relevant undertaker. These are supplemented by further land rights provided by the Hinkley Connection DCO. The majority of towers will be accessed from the prescribed routes, bellmouths and haul roads identified within the original CTMP. A number of towers are not accessible from haul roads and their associated bellmouths. Access rights were secured through the DCO with these off-road routes included within the redline boundary. For the avoidance of doubt, the construction traffic routes on the public highway to these access points, which are extensions / deviations from the prescribed new build routes, are included within this CTMP Addendum and the updated plans in Appendix A.

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2.2.8 Table 2-3 summarises the number of towers and access points separate to those specified in the original CTMP to enable the dismantling of the 132kV overhead lines for Stage 7.2 and Stage 10.1.

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Table 2-3 Summary of access requirements for dismantling works

Access requirements for dismantling works Stage 7.2 Stage 10.1

Length of overhead line to be dismantled as part of Stage 25.9 Km 37.2 Km

Total number of towers to be dismantled as part of Stage 99 133

Total number of access points from public highway required 54 49

Of which are via prescribed bellmouths 14 16

Of which are additional accesses 40 33

Total number of towers accessed from prescribed bellmouths 45 89

Total number of towers accessed from additional accesses 54 44

2.2.9 The additional access to be used are all existing accesses to the public highway, which are typically field gates or private service roads where access was secured through the DCO or is being/has been agreed with landowners. Due to the limited nature of the construction vehicles required for dismantling each individual tower, each of the identified accesses is suitable for the types of construction vehicles required without the need for additional works (i.e. widening etc.). 2.2.10 Table 2-4 sets out the additional dismantling routes for Stages 7.2 and 10.1, with number in brackets after each route indicating the number of towers to be accessed for dismantling from that route. Some routes may have multiple access points. The routes noted in the table are all extensions to the existing prescribed construction routes, and are shown in the updated plans in Appendix A. The assessment of the usage of these routes is provided in Section 3.7.

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Table 2-4 Summary of additional access routes required for dismantling works

Stage 7.2 Stage 10.1

A371 Banwell Road (2) Burtle Road (1) Royal Portbury Dock Road B3133 Kenn Road (1) (5) Max Mill Lane (2) B3141 Causeway (2) Lample Road (1) Gordano Way / Marsh Webbington Road (3) Woolavington Road (3) Wemberham Lane (1) Lane (5) Pill Road (2) Crancombe Lane (3) Drove Way (2) Puxton Lane (1) Vole Road (2) Bradney Lane (4) Portview Road / Sheepway (1) Catherine Street (2) Northwick Road (1) Chedzoy Lane (3) A369 Portbury Hundred B4054 Avonmouth Harp Road (1) Front Street (1) (2) Road / Atlantic Road B3139 Causeway (3) Portwall Drove (3) Casewell Lane / (1) Whitehouse Lane (4) Southwick Road (3) Park Wall Drove (1) Second Way (2) Silver Street / Fosse Way / Hack Mead Lane (2) A372 Westonzoyland Road Mead Lane (1) Fryth Way (2) (2) Merry Lane (2) Fieldfare Avenue (3) Rhyne View, Nailsea (1) Bridgwater Substation (2) B3128 Clevedon Road Hackness Road (1) Leighwood Drive, Nailsea (3) (3) Cuckoo Lane (2) West End Lane (1) Fir Leaze & North Lane, Nailsea Wall Road (1) Nailsea (1)

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3 ASSESSMENT

3.1 Overview 3.1.1 The following sections provide further context and background information regarding the proposed usage of individual routes, to enable an assessment to be undertaken for each proposed route. 3.1.2 The purpose of this assessment is to determine whether these updates would ‘give rise to any materially new or materially different environmental effects from those assessed in the Environmental Statement’, pursuant to Requirement 1 of the DCO. This also includes consideration of the cumulative impacts of the updates proposed. Of the environmental topics considered within the Environmental Statement, traffic and transport, air quality and noise are vibration are most relevant to the updates outlined here, with the remaining topics scoped out of this assessment for the majority of the proposed updates. 3.1.3 As per Table 2-1, and has been confirmed through the pre-application consultation comments from the relevant planning authorities, the following updates have been scoped out of further assessment: • Stage 4: access from Junction 20 of the M5; • Stage 10: access to 400kV overhead line pylons; and, • Stage 11: access to Shurton Line Entries. 3.1.4 The following sections consider the remaining updates in turn. All programme dates and construction traffic estimates are the best available at the time of writing (May 2021), and are subject to update as the construction methodologies are developed further for individual Stages. However, all figures provided are considered ‘reasonable worst case estimates’, to ensure that the conclusions of this CTMP Addendum would not fundamentally update should any of the underlying information need to be revised to account for updates to the construction programme or methodology.

3.2 Use of Whitehouse Lane for access to and from the B3128/Clevedon Road 3.2.1 Construction works for Stage 4 of the project commenced on 6 January 2020. 3.2.2 Cuckoo Lane, which is one of the prescribed routes for construction traffic for Stage 4, is subject to a 7.5T weight limit that commences at its junction with Clevedon Road/B3128. The restriction was introduced in June 2000 to prevent HGV traffic travelling between the B3124 (Portishead) and the B3128 (Wraxall). The restriction has an environmental purpose and not a structural purpose. Under the existing Weight Limit Order, National Grid has legal rights to access the bellmouths in Cuckoo Lane and Whitehouse Lane within the section covered under the weight limit. 3.2.3 Following pre-application consultation on the CTMP Addendum, National Grid have confirmed that limited access via Cuckoo Lane needs to be retained (independent of the ‘W’ route Stage 4 works) to enable the dismantling of parts of the existing 132kV overhead line, as part of Stage 10.1. 3.2.4 Prior to the commencement of construction activity for Stage 4, it became obvious that Cuckoo Lane was unsuitable for construction traffic due to its narrow

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width which could impose safety risks. Engagement with North Somerset Council (Local Highways Authority) took place between February and March 2020. It was informally agreed between National Grid and the local highway authority as required by the CTMP that the construction traffic associated with Stage 4 would use the full extent of Whitehouse Lane to access Clevedon Road rather than Cuckoo Lane. 3.2.5 The alternative route proposed is approximately 1km longer than the Cuckoo Lane route, of which c.400m is via B3128 Clevedon Road and c.600m via Whitehouse Lane. There are fewer properties located on Whitehouse Lane than Cuckoo Lane and no sensitive receptors. 3.2.6 The proposed route would be used between May 2021 and July 2025 for the Stage 10.1 works. On average, over this period there would be 37 vehicles per day associated with the new build works, distributed throughout the course of the day, resulting in an average of 3 additional vehicles per hour. It is expected that c.60% of these vehicles would be LGVs (22 vehicles per day), and the remainder would be HGVs (15 vehicles per day). 3.2.7 For a limited period additional construction traffic associated with the dismantling works would also use the route, with 11 pylons to be dismantled accessed from the W-Route-BM08 bellmouth. The pylons would be accessed in two phases between August 2021 - August 2022 and June 2023 - June 2024. For the duration of the dismantling works, an additional 8 vehicles per day, on average, would utilise the route (6 HGVs and 2 LGVs, on average). 3.2.8 The proposed update was considered by National Grid in terms of the DCO and the assessments carried out as part of the DCO, including those mitigation measures committed to in Section 6 of the CTMP. It was concluded that the temporary increase in construction traffic on Whitehouse Lane outweighs the use of designated Cuckoo Lane which could otherwise impose potential safety concerns due to its narrow width. 3.2.9 The proposed route was considered against the Transport Assessment and the conclusions of the Environmental Statement, concluding that the temporary use of Whitehouse Lane, even with the minimal increase of temporary construction traffic, would not create new or different environmental impacts to those already assessed as part of the DCO for this area. A summary of this review is provided in Table 3-3. 3.2.10 Within the Transport Assessment submitted as part of the DCO application, junctions were modelled to assess the impacts of the proposed development on their capacity. For vehicles accessing Cuckoo Lane, the junction at Clevedon Road/ B3128 Tickenham Hill was modelled. The number of vehicles utilising this junction would not update as a result of the use of Whitehouse Lane instead of Cuckoo Lane. Similarly, the number of vehicles accessing the site from the north would not update as a result of this amendment.

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Table 3-1 High-level environmental review of Whitehouse Lane proposed update

Environmental Conclusion Assessment topic

Traffic and transport The proposed utilisation of a more significant road and junction has the potential to bring beneficial effects relating to driver delay and accidents and safety compared to the baseline assessment. The magnitude and duration of the construction traffic that would utilise Whitehouse Lane (an average of 3-4 vehicles per hour) is insignificant in environmental terms and relative to the highway link and junction capacity. Therefore, in the overall context of the wider project this would not give rise to any materially new or materially different environmental effects from those assessed in the Environmental Statement with respect to traffic and transport.

Air quality The area considered through the original air quality assessment would not experience a change in traffic numbers. The magnitude and duration of the construction traffic that would utilise Whitehouse Lane would not result in any material changes to air quality on Whitehouse Lane. Therefore, the proposed update would not result in any materially different environmental effects to those found in the Environmental Statement with respect to air quality.

Noise and vibration There are fewer properties located on Whitehouse Lane than Cuckoo Lane (just one property, compared to c.4 on Cuckoo Lane). The impact associated with noise and vibration on the properties at Cuckoo Lane would be reduced by the proposed update which would divert construction traffic through Whitehouse Lane. While the impact on the property located at Whitehouse Lane would be slightly greater due to diversion of the construction traffic, it is considered that due to its minor and temporary nature, this would have negligible impact on the local properties. The proposed update would not result in any materially different environmental effects to those found in the Environmental Statement.

3.2.11 The impact of the use of Whitehouse Lane for additional construction traffic would be of a temporary and minor nature. It is considered that the proposed update would not alter the conclusions of the Environmental Assessment or the Transport Assessment nor impose new significant environmental effects to those assessed in the ES. The proposed update would take into account proposed mitigation measures as listed in Table 3.1 and Section 6.3.1 of the CTMP.

3.3 Use of additional access route to Seabank Substation 3.3.1 This update seeks to prescribe use of an existing access route to the substation through the Seabank power station complex. The primary reason for this update is that the DCO-approved access route to the substation (which utilises the haul road through Crooks Marsh) would require significant ground works and would disturb the existing underlying contaminated material at Crooks Marsh.

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3.3.2 As existing infrastructure, necessary consents and access arrangements are already in place for this access to the substation. This route has already been used in the past for installation and replacement of the super-grid transformers on the site. 3.3.3 The necessary additional length of public highway required for the access is short (c.1km) and runs through an industrial area. There are no residential receptors or community uses on this stretch of the A403 Severn Road 3.3.4 The fallback position of the CTMP approved route is the construction of a haul road through an area of scrub to the side of the power station. In common with much of the surrounding area, this land is expected to contain historic buried contaminants. 3.3.5 A high-level environmental review suggests that while there will be some beneficial effects to the proposed update, these would not be material in the context of the wider scheme.

Table 3-2 High-level environmental review of Seabank substation proposed update

Environmental Conclusion Assessment topic

Traffic and transport While there would be a greater distance travelled on the highway, the existing access to the power station has better visibility than the consented haul road access at a bend in the road. Regardless, this road has good design standards and light traffic. There is negligible effect which would not result in materially different effects to those found in the Environmental Statement.

Air quality The slightly longer road route could result in more pollution, but this may be balanced by the avoidance of a steep slope and narrow access on the consented route. Nonetheless, there are no receptors in the vicinity to be affected. There is negligible effect which would not result in materially different environmental effects to those found in the Environmental Statement.

Noise and vibration The slightly longer road route could result in more noise and vibration effects, but there are no receptors in the vicinity to be affected by this. There is negligible effect which would not result in materially different environmental effects to those found in the Environmental Statement.

Contaminated land There is significant potential for contamination on the Crooks Marsh site, which may be disturbed by the construction of a haul road access as per the approved CTMP. Using the existing substation access would eliminate the potential risk in this location, resulting in a beneficial effect. This beneficial effect is insignificant compared to the wider works on Crooks Marsh and across the project, so the proposed update would

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Environmental Conclusion Assessment topic

not result in any materially different environmental effects to those found in the Environmental Statement.

Biodiversity The use of an existing road rather than a new route cut through scrub and woodland would have a beneficial effect, as damage to plants and wildlife would be reduced. However, the scale of the proposed update would not result in any materially different environmental effects to those found in the Environmental Statement.

3.4 Use of Cannington Bypass 3.4.1 Cannington bypass was constructed after the DCO was made in 2016. This route would provide a more suitable access route as it would direct construction traffic around Cannington rather than through the town. 3.4.2 Whilst reference was made in the TA to Hinkley Point C construction utilising the bypass to access the nuclear power stations, the use of the bypass is not prescribed in Annex C of the approved CTMP, which instead permits traffic through the town. 3.4.3 Use of the bypass would clearly reduce the impact of construction traffic on sensitive receptors in Cannington. This route would have been used in the approved CTMP were it available at the time, as it is clearly beneficial. 3.4.4 It is expected that the peak daily construction traffic movements for Stage 11 would be up to 28 HGV and 28 LGV two-way movements. The total duration of the works is currently forecast to run from Q1 2021 to Q4 2024. 3.4.5 Construction traffic movements would be distributed throughout the course of the working day, based on the working hours of Monday to Friday 0700 to 1900 and weekends 0800 to 1700 (as per Schedule 3 Requirement 7 of the DCO). The peak hourly average would therefore be around 5 vehicles per hour. 3.4.6 The small number of project construction vehicles using the bypass instead of the town centre would not be material in the context of the overall traffic flows or the highway junction and link capacity. There are fewer than 10 residential receptors within 100m of the bypass, which passes largely through agricultural land. 3.4.7 The following high-level environmental review considers whether the proposed update would result in any materially new or materially different environmental effects from those assessed in the Environmental Statement.

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Table 3-3 High-level environmental review of Cannington Bypass proposed update

Environmental Conclusion Assessment topic

Traffic and transport The proposed utilisation of a more significant road and junction has the potential to bring beneficial effects relating to driver delay and accidents and safety compared to the baseline assessment. The magnitude of the construction traffic that would utilise the bypass (an average of 5 vehicles per hour) is insignificant relative to existing traffic flows. Therefore, in the overall context of the wider project this would give rise to any materially new or materially different environmental effects from those assessed in the Environmental Statement with respect to traffic and transport.

Air quality The area considered through the original air quality assessment would not experience a change in traffic numbers. The magnitude and duration of the construction traffic that would utilise the Cannington Bypass would not result in any material changes to air quality affecting those receptors adjacent to the bypass. Therefore, the proposed update would not result in any materially different environmental effects to those found in the Environmental Statement with respect to air quality.

Noise and vibration The additional noise exposure of the residential receptors adjacent to the bypass to construction traffic would be negligible. Therefore, the proposed update would not result in any materially different environmental effects to those found in the Environmental Statement.

3.5 Use of existing access route to Portishead Substation 3.5.1 While Portishead substation is marked in Annex C of the CTMP, no access route is shown. The CTMP prescribes routes to new bellmouths only and does not include access to existing infrastructure. 3.5.2 Consideration has been given to extending the haul road from the south, to avoid construction traffic utilising the local road network through Portishead. However, this is infeasible for a number of reasons, including ground conditions, the presence of watercourses and the impact on the secure perimeter fencing of the substation. 3.5.3 North Somerset Council have confirmed in their response to the pre-application consultation that access to the existing substation for large vehicles through the Ashlands development site in Portishead was allowed for in the design of the road layout along Phoenix Way, Stonechat Green and The Finches. 3.5.4 Nevertheless, usage of this route would constitute an intensification of traffic on this approved route. Table 3-4 summarises the access requirements for the route, including Stage 9 works relating to Portishead 132kV WPD Substation and BW Route undergrounding, and the dismantling of 3 towers of the 132kV overhead line as part of Stage 10.1

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Table 3-4 Summary of access requirements for Portishead substation

Stage 9 Stage 10.1

Duration of access required TBC within June 2023 – TBC within August 2021 - February 2024 August 2022

Total construction traffic movements 1,040 159

Of which LGVs 0 0% 144 90%

Of which HGVs 1,040 100% 15 10%

Average daily construction traffic 16 12 movements

Average hourly construction traffic 1-2 2 movements

3.5.5 The route is through a predominantly residential area of Portishead, and so there are a high number of residential receptors directly adjacent to the route. Additionally, there is sensitive receptor – Trinity Anglican Methodist Primary School – c.150m to the south of Phoenix Way, indicating the presence of school- aged children walking/cycling along the route is likely at certain times of the day. 3.5.6 The peak hourly construction traffic movements would only be 1-2 vehicles per hour during both Stage 9 and Stage 10.1. However, recognising the presence of the school, movements will be timed to avoid peak school pick-up/drop-off times where possible. 3.5.7 The following high-level environmental review considers whether the proposed update would result in any materially new or materially different environmental effects from those assessed in the Environmental Statement.

Table 3-5 High-level environmental review of Cannington Bypass proposed update

Environmental Conclusion Assessment topic

Traffic and transport The overall increase in traffic levels would be negligible relative to existing traffic flows. The presence of a primary school increases the number of vulnerable road users at certain times of the day, and so traffic movements will be timed to avoid peak school pick- up/drop-off times where possible to mitigate the low potential increase in risk to road safety. Overall, the proposed usage is not of sufficient magnitude or duration to result in any materially new or different environmental effects to those found in the Environmental Statement.

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Environmental Conclusion Assessment topic

Air quality The additional residential receptors would not experience a material change to air quality as a result of the negligible increase in traffic associated with the construction works.

3.6 Stage 10.1 additional access routes 3.6.1 Subsequent to the original pre-application submission, four additional updates to access routes have been identified as necessary amendments in order to facilitate the construction of the Stage 10.1 400kV overhead line in the Avonmouth area. These relates to: • Stage 10: Royal Portbury Dock Road; • Stage 10: Gordano Way / Marsh Lane; • Stage 10: Kings Weston Lane; and, • Stage 10: Moorhouse Lane. 3.6.2 Royal Portbury Dock Road is a proposed extension to the prescribed route to gain access through Bristol Port via its private service road network, as the alternative prescribed route is unrepresentative of actual site conditions. Access has been agreed with Royal Portbury Docks and the Port Police to utilise the service road network of the port, which is well suited to HGVs and would not impact upon the general public. 3.6.3 A minor extension to the prescribed route of c.500m is required utilising Gordano Way / Marsh Lane, as the alternative prescribed route is unrepresentative of actual site conditions. The route is within an industrial / commercial area heavily trafficked by HGVs, with five receptors adjacent to route proposed. 3.6.4 An extension to the prescribed route along Kings Weston Lane is proposed to enable access through the Wessex Water Sewage Treatment Works, as the prescribed route is not deemed suitable following the identification of three large above ground sewer mains. The extension is c.400m long before entering the private service roads within the Wessex Water site, usage of which has been agreed with Wessex Water. The route is suitable for construction traffic and has no sensitive receptors adjacent to it. 3.6.5 Severn Road / Moorhouse Lane is required as an access route to Henbury Loop railway line, over which scaffold fall protection must be installed during construction, which will then be dismantled upon the completion of this section of the overhead line. No suitable alternative access to the railway is available. The

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extension to the prescribed route is c.2.5km, passing through the village of Hallen, which contains a number of residential receptors. 3.6.6

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Table 3-6 sets out the estimated traffic generation and usage requirements for each of these four routes, based on the construction methodology being developed by the contractor appointed for delivering Stage 10.1 of the project.

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Table 3-6 Summary of access requirements for new build construction works

Royal Gordano Kings Moorhouse Portbury Way / Marsh Weston Lane Dock Road Lane Lane

Duration of new build May 2021 – July 2025 May 2025 – construction works July 2025

Total new build construction 6,576 14,368 7,074 560 traffic movements

Of which LGVs 4,728 (72%) 9,600 (67%) 4,282 (61%) 320 (57%)

Of which HGVs 1,848 (28%) 4,768 (33%) 2,792 (39%) 240 (43%)

Average daily construction traffic 6 14 7 14 movements

Average hourly construction 0.5 1.2 0.6 1.1 traffic movements

Notes: • Figures inclusive of two-way trips to and from worksites. • Daily forecasts assume weekday working only. However, some weekend working may be required. • Hourly forecasts assume 0700 to 1900 working day, as per Schedule 3 Requirement 7 of the DCO.

3.6.7 The following high-level environmental review considers whether the proposed update would result in any materially new or materially different environmental effects from those assessed in the Environmental Statement.

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Table 3-7 High-level environmental review of Stage 10.1 proposed update

Environmental Conclusion Assessment topic

Traffic and transport The overall increase in traffic levels would be negligible relative to existing traffic flows and are in largely industrial areas with high proportions of HGVs and limited pedestrian flows. Adjacent junctions on these routes were assessed within the Transport Assessment, and the subsequent TA Sensitivity Test and TA Addendum, including: • Royal Portbury Dock Road / Gordano Way / Portbury Way • A403 Chittening Road / Severn Road • A403 St Andrew’s Road / Kings Weston Lane For the Royal Portbury Dock Road / Gordano Way roundabout, the currently prescribed construction routes utilise this junction. The proposed amendment would necessitate the use of different arms to those assessed in the TA junction model. However, on the basis of the magnitude of the forecast hourly flows in Table 3-6, and the maximum Ratio of Flow to Capacity (RFC) of 0.29 at this junction reported in the TA, this change is not considered to result in a material change the operation of the junction. For the A403 St Andrew’s Road / Kings Weston Lane signalised T- junction, the proposed amendment to utilise the Wessex Water access would not result in any change to the previously assessed utilisation of this junction, as the route is a slight deviation from the currently prescribed route to bellmouth G-Route-BM03. It should also be noted that mitigation is currently secured at this location through the CTMP to restrict HGVs movements to outside of peak hours. For the A403 Chittening Road / Severn Road T-junction, the proposed amendment to enable scaffold access via Moorhouse Lane would not result in in any change to the previously assessed utilisation of this junction, as the route is an extension to the currently prescribed route to bellmouth C-LD121-BM01. There is potential for a slight increase in driver delay on Moorhouse Lane, as the western extent of the road is unsuitable for passing in some places. However, the existing road to the west of Hallen is very lightly trafficked, reducing the chance of conflicts and so any delays would be minimal. Construction traffic will be suitably managed by the appointed contractor, with any identified Temporary Traffic Management to be agreed with the LHA.

Air quality The additional residential receptors would not experience a material change to air quality as a result of the negligible increase in traffic associated with the construction works.

Noise and vibration The additional noise exposure of the residential receptors in Hallen to construction traffic would be negligible. Therefore, the proposed update would not result in any materially different environmental effects to those found in the Environmental Statement.

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3.7 Access required for dismantling works 3.7.1

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3.7.2 Table 3-8 provides a summary of total, daily and hourly forecast construction traffic movements associated with the additional dismantling routes specified in

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3.7.3 Table 2-4 and shown in the plans in Appendix A. All other dismantling traffic will utilise prescribed bellmouths and haul roads. 3.7.4 The forecasts are based on the construction methodology being developed by the contractor appointed for delivering these Stages of the project. The figures are considered a reasonable worst-case estimate, although further refinement of the construction methodology will seek to identify efficiencies where possible. 3.7.5 Dismantling of the overhead lines will take places sequentially, with discrete sections of (generally) three to four towers being taken down at any one time. Therefore, whilst the duration of the total works exceed one year for each of the stages, the impacts on individual routes will be limited by the new of towers accessed from that route. 3.7.6 The variation in the split between LGVs and HGVs for Stage 7.2 and Stage 10.1 is a result of the different types of areas in which the overhead lines and towers are situated. Stage 7.2 includes more rural locations with a reduced need for cranes to aid with the dismantling, and fewer locations over sailed by the lines necessitating the installation of scaffold crash deck fall protection.

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Table 3-8 Summary of access requirements for dismantling works

Stage 7.2 Stage 10.1

Total number of towers accessed from additional 54 44 accesses

Duration of dismantling works July 2021 – August 2021 – March 2022 August 2022 (8 towers) May 2023 – June 2024 (36 towers)

Average construction traffic movements per 80 205 tower

Of which LGVs 72 (90%) 3.7.7118 (58%)

Of which HGVs 8 (10%) 87 (42%)

Total dismantling works construction traffic 4,320 8,804 movements

Average daily dismantling works construction 22 29 traffic movements

Average hourly dismantling works construction 1-2 2-3 traffic movements

Notes: • Figures inclusive of two-way trips to and from worksites. • Stage 10.1 bounding forecasts based on 36 towers dismantled between May 2023 - June 2024. • Daily forecasts assume weekday working only. However, some weekend working may be required. • Hourly forecasts assume 0700 to 1900 working day, as per Schedule 3 Requirement 7 of the DCO. • Figures represent only those towers to be dismantled from ‘new’ routes secured through this CTMP Addendum. All remaining dismantling traffic will utilise prescribed bellmouths and haul roads.

No single route identified in

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3.7.8 Table 2-4 and shown in the plans in Appendix A is used to access more than five towers to be dismantled, and the vast majority (15 of 23 routes for Stage 7.2, 18 of 23 routes for Stage 10.1) are only required to access one or two towers. Therefore, as the forecasts are derived from dismantling of three to four towers concurrently, the maximum traffic on any individual route would only be an average of 2-3 additional vehicles per hour, and in majority of cases the traffic would be distributed across multiple routes, resulting in even lower daily and hourly totals. 3.7.9 The duration any individual route would be utilised would also be time-limited. The average duration for a typical four tower section of overline to be dismantled is three weeks for Stage 7.2 and seven weeks for Stage 10.1 (with the difference largely due to the amount of scaffolding to be installed, as stated previously). 3.7.10 This forecast level of construction traffic is judged to be insignificant in terms of highway link and junction capacity, including at peak hours, and so no further assessment is deemed necessary. 3.7.11 The following high-level environmental review considers whether the proposed update would result in any materially new or materially different environmental effects from those assessed in the Environmental Statement.

Table 3-9 High-level environmental review of dismantling routes proposed update

Environmental Conclusion Assessment topic

Traffic and transport The magnitude and duration of construction traffic on the additional routes would have a negligible impact on driver delay, pedestrian delay, severance and pedestrian amenity in the context of existing traffic flows. Highway safety is not judged to be materially affected as all routes and accesses are currently regularly trafficked and are suitable for the nature of the required construction traffic.

Noise and vibration The additional noise exposure of the residential receptors adjacent to the additional routes to construction traffic would be negligible in the context of existing traffic flows.

3.8 Consideration of cumulative impacts 3.8.1 Schedule 4, Part 1 of the Infrastructure Planning (Environmental Impact Assessment) Regulations 2009 (as amended); sets out that the ES must include ‘a description of the likely significant effects of the development on the environment, which should cover the direct effects and any indirect, secondary,

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cumulative, short, medium and long-term permanent and temporary, positive and negative effects of the development.’ 3.8.2 As part of the DCO application, Volume 5.17.1, Chapter 17 of the ES set out the assessment of the Cumulative Effects associated with the development. 3.8.3 The Institute of Environmental Management and Assessment (IEMA) report, ‘The State of Environmental Impact Assessment Practice in the UK’ recognises two major sources of cumulative effects; “Inter-project” and “Intra-project” effects, both of which were assessed within the ES: Inter-project Effects 3.8.4 Inter-project effects are those that occur “as a result of the likely impacts of the proposed development interacting with the impacts of other development in the vicinity”. For example, construction traffic effects of the Proposed Development combined with the construction traffic effects of another major development using the same access routes may result in cumulative effects on the surrounding highway network. Intra-project Effects 3.8.5 Intra-project effects are those that “occur between different environmental topics within the same proposal as a result of that development’s direct effects”. These effects are considered in each of the ES technical chapters where relevant. 3.8.6 Considering inter-project effects, the only significant proposed or authorised development that would interact with these proposed updates (separate to those effects already identified and reported in the ES) would be the Hinkley Point C Power Station. Construction programmes and construction routes overlap, particularly in the vicinity of the power station. 3.8.7 The proposed amendment to utilise the Cannington Bypass, which has been constructed specifically to enable construction traffic from the power station to bypass the village of Cannington, would increase the interaction between these two streams of construction traffic. However, as set out in Section 3.4, the volumes of traffic proposed to utilise the bypass are insignificant in the context of the existing traffic flows (including HPC construction traffic), and so would not result in any new or materially different intra-project effects. 3.8.8 The proposed amendment for the Shurton Line entries would also increase the interaction between these two streams of construction traffic. However, as set out in Section 2.1, the length of additional highway being utilised is minimal, and usage of private EDF roads within the power station has been agreed with EDF. Similarly, National Grid, EDF and the appointed contractors are working collaboratively to agree suitable traffic management arrangements were required to minimise the impacts on both projects. Therefore, this update would not result in any new or materially different intra-project effects. 3.8.9 Intra-project effects and the in-combination interactions between different environmental topics (where relevant) have been considered in the previous sections for each proposed amendment. This has concluded that the updates will not give rise to any materially new or materially different environmental effects for those environmental topics.

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3.8.10 Summarising the cumulative impact of updates relating to traffic and transport, it is accepted that the geographical scope of the area impacted by these updates is large. However, this is mitigated by the temporary nature of works undertaken – particularly the dismantling of the 132kV overhead lines – where works are to be undertaken sequentially, and so no individual route will be utilised for an extended duration. The broad geographical scope also reduces the interaction between any of the proposed updates (and the prescribed construction routes that are retained), and the majority of the updates are minor diversions or extensions to the previously assessed routes. The estimated traffic flows for the amendments are also negligible in the context of highway link and junction capacity, and utilisation of these proposed amended routes would remain subject to the committed mitigation measures in Section 6 of the CTMP. In giving consideration to all these factors, it is judged that these updates will not give rise to any materially new or materially different environmental effects

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Appendix A. Plans

Approval of this CTMP Addendum by the LPAs would authorise the use of the construction traffic routes set out within the following plans included as Appendix A of this document. The previously approved construction traffic routes hitherto defined by the plans within Annex C of the CTMP (document no. EN020001-004849-5.26.5C). which forms Appendix 4 of the CEMP and is secured through Requirement 5 of the DCO, would be superseded.

Plans to be Authorised Figure No. ANNEX C Drawing No. G1979.2504 Issue D Total Sheets 13

Plans to be Superseded Figure No. ANNEX C Drawing No. G1979.2504 Issue B Total Sheets 12