Thorpe Marsh CCGT Power Station ENVIRONMENTAL STATEMENT SUPPLEMENTARY INFORMATION

Transcription

1 Thorpe Marsh CCGT Power Station ENVIRONMENTAL STATEMENT SUPPLEMENTARY INFORMATION Final June 2011

2 Thorpe Marsh CCGT Power Station ENVIRONMENTAL STATEMENT SUPPLEMENTARY INFORMATION Final June 2011 SKM Enviros Victoria House Southampton Row London WC1B 4EA Tel: Fax: Web: COPYRIGHT: The concepts and information contained in this document are the property of Sinclair Knight Merz (Europe) Ltd. Use or copying of this document in whole or in part without the written permission of Sinclair Knight Merz (Europe) Ltd constitutes an infringement of copyright. LIMITATION: This report has been prepared on behalf of and for the exclusive use of Sinclair Knight Merz (Europe) Ltd s Client, and is subject to and issued in connection with the provisions of the agreement between Sinclair Knight Merz (Europe) Ltd and its Client. Sinclair Knight Merz (Europe) Ltd accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this report by any third party. The SKM logo trade mark is a registered trade mark of Sinclair Knight Merz Pty Ltd.

3 Contents 1. Introduction 1 2. Change to Single Stack Design Introduction New Site Layout Landscape and Visual Photomontage Comparison Structural Mass Comparison Air Quality Noise Traffic and Transport Summary 5 3. Demolition of the Cooling Towers Potential Impacts and Cumulative impacts Summary 7 4. Amendment to Section 36 Boundary 8 5. Figures 9 SKM Enviros JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE i

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5 Document history and status Revision Date issued Reviewed by Approved by Date approved Revision type 1 03/06/2011 A Heatley JP Wale 07/06/2011 Distribution of copies Revision Copy no Quantity Issued to Printed: 15 June 2011 Last saved: File name: Author: Project manager: Name of organisation: Name of project: Name of document: Document version: Project number: 15 June :22 AM I:\JEIA\Projects\JE10440\EE10440\Deliverables\Reports\June DECC Request\JE10440-fin-rep-ThorpeMarshEIA-DECC J Bletcher and JP Wale JP Wale Thorpe Marsh Power Limited Thorpe Marsh CCGT Power Station Environmental Statement - Final JE10440 SKM Enviros JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE iii

6 1. Introduction Thorpe Marsh Power Ltd (TMPL) is seeking to develop a gas-fired Combined Cycle Gas Turbine (CCGT) electricity generating station ( the project ) on part of the site of the former coal-fired Thorpe Marsh Power Station Estate ( the former power station ), 1 km northwest of the village of Barnby Dun, South Yorkshire, within the Doncaster Metropolitan Borough Council (DMBC) area. The new power station is initially expected to have a generating capacity of around 960MW, with the potential for expansion to up to 1500 MW and will be known as Thorpe Marsh Power Station ( the Power Station ). An Environmental Statement (ES) presenting the findings of an Environmental Impact Assessment (EIA) was submitted to the Department for Energy and Climate Change (DECC) by Sinclair Knight Merz (SKM), on behalf of TMPL, to accompany the project s Section 36 Consent application in February The ES was subsequently amended in May 2010 and again in September Those documents should be referred to for relevant further detail as necessary. Following submission of the September 2010 amendment, DECC has requested submission of supplementary information to support the Section 36 determination process. This request relates to two issues, which are detailed in the following sections with associated supplementary information: Recent changes in the interpretation of demolition planning requirements and a need for EIA: demolition of the existing cooling towers at Thorpe Marsh is part of a separate planning application and the landowner Able UK Ltd is currently undertaking an EIA. Demolition of the cooling towers does not form part of the baseline for the Thorpe Marsh EIA, but DECC has requested supplementary information from TMPL regarding the potential for cumulative impacts from the demolition works with regard to relevant aspects of the Thorpe Marsh EIA, including air quality (dust), noise (use of explosives), transport and period of site works. Changes to the power station design as a result of the ongoing environmental permitting regulations (EPR) permit application process: the design has changed from a multi-stack multi-flue, to a multi-stack single-flue (i.e. a single stack as observed from the exterior of the plant). DECC have requested supplementary information on how the proposed design change relates to the landscape and visual, air quality, noise and transport findings of the ES. These issues were discussed in a meeting between representatives of the DECC, TMPL and SKM on 1 st June This supplementary information report has been produced in response to the requirements agreed in that meeting as summarised above. In addition to the above, Section 4 of this document presents an amended Section 36 boundary to accommodate National Grid requirements. This change does not affect the findings of the EIA. SKM Enviros JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 1

7 2. Change to Single Stack Design 2.1. Introduction The site layout used in the amended ES submitted to DECC in September 2010 assumed a worst case scenario of three CCGT trains, three air cooled condensers (ACCs) and three stacks (see Figure 1). As detailed in the ES, this scenario allows for the planned initial construction of two CCGT trains (and two stacks), with potential for a third to follow. The EPR permit application was therefore submitted in December 2010 on the basis of the initial two CCGT trains, two ACCs and two stack configuration. However, discussions with the Environment Agency have since resulted in a change to a single combined stack configuration. Additional air quality modelling has also been undertaken for the new layout to support the EPR application. The amendment of the site layout would not affect the findings of the majority of the technical chapters in the ES. Those technical chapters which could potentially be affected are: Landscape and Visual; Air Quality; Noise; and Transport Given that the change in design layout is highly unlikely to result in effects greater than those considered in the relevant technical assessments in the ES, DECC have not requested that the assessments are revisited and a further ES amendment issued. Instead, this section presents discussion intended to clarify the implications of the revised layout within the context of the findings of the ES New Site Layout The new layout is presented in Figure 2 and has resulted in the removal/repositioning of the following structures: The southern turbine train has been removed; The southern ACC has been removed; The southern stack and northern stack have been removed; and The central stack has been moved north so that is positioned halfway between the two remaining turbine trains. JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 2

8 Comparison with the original layout (Figure 1) clearly shows the reduction in the number of buildings on site and the new single stack location. This visual comparison is will arguably be the most noticeable aspect of the change and is discussed further in the following section Landscape and Visual The perceived landscape and visual impacts from the revised layout will not be greater than those identified in the technical chapter of the ES. It was considered that the following two assessments support this conclusion: A comparison from a single viewpoint (a perceived worst case view taken from the views presented in the ES chapter 1 ); and, A comparison of the structural mass of the development using oblique 3-D models of the new buildings and layouts (not previously used in the ES chapter). These two comparisons are discussed in the following sections Photomontage Comparison The viewpoint chosen for the photomontage comparison was considered to be the closest viable 2 viewpoint from the original assessment. This location offers the clearest view of the proposed power station and, therefore, the most striking depiction of the potential change in the visual impact due to the new site configuration. Figure 3 compares the original baseline view (containing the existing cooling towers) and three stack photomontage produced for the ES technical chapter, with a photomontage of the proposed revised site layout. It is considered that the comparison demonstrates that the potential landscape and visual impacts of the revised site layout are not greater than those of the existing assessment. The key changes are summarised as follows: 1 Viewpoint1atBarnbyDunCanalMooringsfromtheoriginalES.Thisisaperceived worstcase scenario. Itisnotedthattheremaybeviews,mostnotablyfromdirectlysouthornorthofthesite,whereno significantchangeisnoticeablebecausetheturbinetrains,stacksandaccsruninparallelonawesteast axisandwherebuildingsareremoved,identicalbuildingsfortheremainingturbinehallsetcarestillvisible. However,anypotentialimpactsfromtheseviewsareunlikelytobegreaterthanthoseintheESchapter. 2 Originallyviewpoint23fromBanksideCottageswaschosenforthecomparisonbutthepositionofthe vegetationcompletelyobscuredthestackonthenewlayoutphotomontage. JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 3

9 Removal of buildings: The removal of the southern turbine train removes the southern Turbine Hall and southern stack from the photomontage. The northern stack has been removed, leaving just one stack which has been slightly repositioned. Removal of structures: With the removal of the southern ACC, the remaining two ACCs are no longer visible, being screened by the vegetation in the middle ground. Changed point of focus: With the reduction in the number of buildings, the mass of the buildings has been reduced and the remaining stack becomes the most prominent point of focus. This compares to the broader-massed three-stack development in the original photomontage. The only viewpoints where there will not be a significant reduction in the impact on the landscape will be from the north and south of the site. The landscape will not be impacted from these viewpoints because the turbine trains, stacks and ACCs run in parallel on a west-east axis. This means that the removed buildings will be replaced in the landscape by the next series of buildings, which had previously been screened by/ were screening the removed buildings Structural Mass Comparison The change in the site layout has resulted in a reduction of the structural mass of the development compared with the baseline and three-stack scenario, as shown in Figure 4. The 3-D oblique viewpoint provides a unique visual conceptual tool, allowing the viewer to gain a feel for the differences in potential impacts. It is considered that this view also supports the conclusion that the potential effects of the revised layout are not greater than those determined in the ES technical chapter Air Quality The change in site layout was requested by the Environment Agency as part of the EPR permit application discussions. The revised layout required an associated Air Quality assessment as the combined flues in one stack could potentially change distribution of emissions to air and associated impacts of the proposed development on the surrounding air quality. The report presented to the Environment Agency concluded that effects of the amended site layout are not greater than outlined in the assessment presented in the ES. It also concludes that the amended layout will not have an increased impact on the SAC at Hatfield Moor. JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 4

10 2.4. Noise The amended site layout will result in six fewer buildings on the site. This means that there will be less material that needs to be delivered to the site and less operational buildings on the site with associated mechanical operational noise. It is therefore anticipated that the noise impacts, as outlined in the original ES, will not be increased due to the amended site layout Traffic and Transport As mentioned in section 2.4, the reduction in the number of buildings on site will result in an anticipated reduction of materials delivered to site. As less materials are expected to be delivered to site, it is not anticipated that the new layout will generate any additional movements to and from the development, beyond those outlined in the ES Summary As the amended site layout has resulted in a reduction of the number of buildings, operational and construction transport noise, and construction transport for the proposed development, it is considered that the potential impacts of the development will not be greater than those detailed within the latest ES. JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 5

11 3. Demolition of the Cooling Towers This chapter discusses the potential for cumulative impacts arising from the works associated with demolition of the existing cooling towers and restoration of the site to the condition agreed in the land lease between TMPL and landowner, Able UK Ltd. The demolition works will be undertaken by Able UK as part of separate planning application and will be subject to a separate EIA commissioned by Able UK. However, as the cooling towers are included as part of the baseline for the Thorpe Marsh EIA and ES, DECC have specifically requested that supplementary information is provided to consider the potential cumulative impacts of the demolition works in the following technical areas: Noise; Air Quality; and Traffic and Transportation. This chapter summarises the potential impacts and mitigation measures that may be included in the demolition and restoration EIA. This chapter can only discuss the potential impacts as the EIA has not been completed Potential Impacts and Cumulative impacts The proposed work that will be undertaken prior to the handover of ownership of the site to TMPL is likely to include: Demolition of the existing cooling towers; and Site clearance and remediation of identified contamination on the site to a standard previously agreed with regulatory authorities. The remediation is likely to include: Crushing of towers material for re-use as aggregate on site during construction of the power plant. Making good the ground to 3 metres below ground level (m bgl) (i.e. including grubbing out of all unwanted remnant foundations); Separation/treatment and removal of any fly tipped wastes; Excavation and removal or covering of any asbestos contaminated material; and Hotspots of contamination may require removal and/or treatment if encountered during the site works. The potential impacts associated with the works for the technical areas requested by DECC are summarised in the following table. JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 6

12 Topic Area Potential Issue/ cause Potential for Cumulative Impacts Air Quality Production of dust through site activities including: Demolition of the cooling towers: Explosives/Explosions Mechanical demolition of the structures e.g. wrecking ball, jack hammer, excavators. Processing /crushing of the material Redistributing of the material around site in order to level the site. The demolition works will be completed a minimum of 6 months prior to the beginning of works to construct the power station. Given this time period, there will be no cumulative impacts associated with the demolition and restoration works, and construction of the power station. Noise Demolition of the cooling towers: Explosives/ Explosions Mechanical demolition of the structures e.g. wrecking ball, jack hammer, excavators Processing /crushing of the material Redistributing of the material around site in order to level the site Traffic and Transportation Duration of works An increase in vehicle movements beyond those indicated in the ES associated with: Workers travelling to site; Demolition vehicles to site; and, Removal of materials (if any) offsite. The potential for elongation of the period of works for the power station construction 3.2. Summary The demolition and restoration works are not anticipated to result in impacts that would require consideration as cumulative impacts within the Thorpe Marsh EIA because the works will take place well before the construction work commences. In order to minimise any potential for cumulative impacts associated with the demolition activities, TMPL have confirmed that the power station construction works will commence only after a minimum period of 6 months has passed from the end of demolition and restoration works. This will ensure the there will be no overlap between the demolition/site restoration works and the construction works. JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 7

13 4. Amendment to Section 36 Boundary As a result of discussions with National Grid, the overall area covered by the Section 36 boundary has been reduced by approximately 2 acres (just under 1 ha) to allow Nation Grid sufficient space to install plant and equipment to enable them to accept the power generated from the Power Station, and for the installation of transformer oil refurbishment equipment. The approximate extent of the revised Section 36 boundary is illustrated on figure 5. This change does not affect the main plant area as defined in the ES, which is the focus of the EIA studies. Accordingly, the change does not affect the EIA findings as presented in the ES. JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 8

14 5. Figures JE10440-fin-rep-ThorpeMarshEIA-DECC Supplementary Report.docx PAGE 9

15 2 JE10440: Drawing Issue A1, June Thorpe Marsh CCGT Figure 1 Original Site Layout Key: Main Plant Areay 1) Turbine Halls 2) Gas Conditioning Building 3) HRSGs 4) CCGT Stacks 5) Generator Transformers 6) Air Cooled Condensers 7) Admin Building 8) Water Treatment Plant 9) Workshop & Store 10) Raw Water Storage Tank 11) Demin Water Storage Tank 12) Fire Water Storage Tank 13) OCGT 14) Auxiliary Boiler 15) Car Park Meters Crown copyright, All rights reserved License number Thorpe Marsh CCGT Power Station 5

16 2 JE10440: Drawing Issue A1, June Thorpe Marsh CCGT Figure 2 Revised Site Layout Key: Main Plant Areay 1) Turbine Halls 2) Gas Conditioning Building 3) HRSGs 4) CCGT Stacks 5) Generator Transformers 6) Air Cooled Condensers 7) Admin Building 8) Water Treatment Plant 9) Workshop & Store 10) Raw Water Storage Tank 11) Demin Water Storage Tank 12) Fire Water Storage Tank 13) OCGT 14) Auxiliary Boiler 15) Car Park Meters Crown copyright, All rights reserved License number Thorpe Marsh CCGT Power Station 5

17 Existing photograph 2010 Layout with 3 stacks 2011 Layout with single stack Drawing Issue A1, 27 May 2011 Photograph and Photomontage Notes G rid reference: Viewpoint elevation: 6 maod Bearing to centre of CCGT: 290 degrees Distance to stack: 800 metres Camera lens(35mm SLR): 50mm Horizontal angle of view: 90 degrees Height of camera above ground: 1.5 metres Recommended viewing distance: 30 cm (when printed on A2 size paper) Date of photography: 22 June 2009 Time of photography: 12.15pm Weather conditions: Overcast Thorpe Marsh CCGT 2010 & 2011 Layout Options Viewpoint 1 Canal Moorings, Barnby Dun

18 Existing layout with 6 cooling towers 2010 Layout with 3 stacks 2011 Layout with single stack Drawing Issue A1, 27 May 2011 Thorpe Marsh CCGT 2010 & 2011 Layout Options

19 E10440: Drawing Issue A1, June Metres 100 Main plant area CCS and Laydown area Section 36 Boundary Thorpe Marsh CCGT Power Station Crown copyright, All rights reserved License number Key: 300 Section 36 Boundary Figure 5 Thorpe Marsh CCGT