ENVIRONMENTAL INFORMATION REPORT SECTION 36 CONSENT VARIATION
DAMHEAD CREEK 2 POWER STATION
Name Job Title Signature Date
Environmental John Bacon / Consultant / February Prepared Associate Director, 2016 Andrew Hepworth Aecom
Technical Technical Director, February Kerry Whalley Review Aecom 2016
February Approved Richard Lowe Director, Aecom 2016
AMENDMENT RECORD
Issue Date Issued Date Effective Purpose of Issue and Description of Amendment
1.0 January 2016 January 2016 S36 Variation Draft EIR for review
2.0 February 2016 February 2016 S36 Variation Final for Issue
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TABLE OF CONTENTS
Page Executive Summary 5 1. Introduction 9 1.1 Purpose of this Document 10 1.2 Planning history of DHC2 10 1.3 Environmental Assessment 11 2. Description of the Development 15 2.1 Proposed Development 15 2.2 Site Location 16 2.3 Application Site Context 17 2.4 Main Buildings and Plant 18 2.5 Process Description 19 2.6 Operational Information 21 2.7 Environmental Permit 22 2.8 Combined Heat and Power (CHP) 23 3. Legislative Framework 26 4. Status of Pre Commencement Planning Conditions 27 4.1 Operational Noise 27 4.2 Contamination of Watercourses 27 4.3 Ecological Enhancement and Protected Species 27 4.4 Ground Contamination 28 4.5 Landscaping and Creative Conservation 28 4.6 Archaeology 29 4.7 Layout and Design 29 4.8 Green Travel Plan 29 4.9 Construction and Construction Traffic 30 4.8 Other Planning Conditions 30 4.8 Other Planning Consents 30 5. Stakeholder Consultation 31 6. Environmental Appraisal 33 6.1 Methodology 33 6.2 Air Quality 35 6.3 Noise and Vibration 42 6.4 Landscape and Visual Amenity 48 6.5 Ecology 61 6.6 Water Quality 75 6.7 Geology, Hydrology and Land Contamination 82 6.8 Traffic and Infrastructure 93 6.9 Cultural Heritage 98
6.10 Socio-Economics 104 7. Conclusions 109
Figures: Figure 1: Damhead Creek 2 CCGT Power Station Site Location Figure 2: Application Site Boundary and Areas 1 to 3 Figure 3: Application Site Boundary on Aerial Photograph Figure 4a: General Arrangement Plan 2015 Figure 4b: General Arrangement Plan 2016 Figure 5: Proposed 1,800 MW CCGT with peaking plant scheme option – Indicative Layout (no CCR) Figure 6: Proposed 1,800 MW CCGT with peaking plant scheme option – Indicative Layout (with CCR) Figure 7: Consented 1,800 MW CCGT-only scheme option – Visualisation Figure 8: Proposed 1,800 MW CCGT with peaking plant scheme option – Visualisation
Appendices: Appendix A: Proposed Section 36 Consent Variation and S90 Direction Consent Notice 2016 Appendix B: Carbon Capture Readiness (CCR) Footprint Report Appendix C: Imperial College, Assessment of the CCR Compliance of the Proposed Damhead Creek 2 1500 MW CCGT + 300 MW OCGT Scheme Appendix D: Air Quality Technical Note Appendix E: Combined Heat and Power Readiness (CHP-R) Report Appendix F: Noise Assessment Appendix G: Visualisations Appendix H: Habitats Regulations Assessment Review 2016 Appendix I: Flood Risk Assessment
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EXECUTIVE SUMMARY ScottishPower (DCL) Limited proposes to construct and operate a power station of up to 1,800 MW electrical output capacity, comprising a Combined Cycle Gas Turbine (CCGT) plant and potentially an Open Cycle Gas Turbine (OCGT) peaking plant, called Damhead Creek 2 (DHC2), on land immediately adjacent to their existing Damhead Creek CCGT power station on the Hoo Peninsula, Kent (see Figures 1 to 3). On 25 January 2011, ScottishPower secured consent under Section 36 of the Electricity Act 1989, for the development, construction and operation of a new 1,000 MW CCGT adjacent to the existing Damhead Creek Power Station. Further to this, on 28 July 2014 ScottishPower secured consent under Section 36(c) of the Electricity Act 1989 to increase the output of Damhead Creek 2 CCGT to 1,200 MW (12.04.09.04/265C) and subsequently in October 2015 this was further increased to 1,800 MW output CCGT (hereafter referred to as the 1,800 MW CCGT-only scheme option). ScottishPower now seek to further vary the existing consent to allow flexibility in the make-up of the plant to include up to 300 MW of OCGT peaking plant. The proposed development therefore now comprises a CCGT/OCGT power station with a total combined electrical capacity up to 1,800 MW, hereafter referred to as the ‘1,800 MW CCGT with peaking plant’ scheme option. This application to vary the consent retains the option of constructing the already consented 1,800 MW CCGT-only scheme option but also includes provision of up to 300 MW as part of that capacity as OCGT units, with the CCGT capacity correspondingly reduced such that the combined output remains at 1,800 MW. This Environmental Information Report therefore focuses on the new variant including the use of peaking plant, as the already consented 1,800MW CCGT-only option was fully assessed as part of the 2015 variation.
A variation to the current Section 36 Consent is therefore now being sought from the Department of Energy and Climate Change (DECC) pursuant to The Electricity Generating Stations (Variation of Consents) (England and Wales) Regulations 2013.
The original Section 36 application in 2009 was supported by an Environmental Statement (ES)1 and the applications to vary the Section 36 Consent in 2014 and 2015 were supported by Environmental Information Reports (EIRs)23. This EIR provides an environmental review of the proposed 1,800 MW CCGT with peaking plant scheme option in the context of the information and findings of the 2009 ES, the 2014 EIR and 2015 EIR and should be read in conjunction with these documents.
The assessments reported in the 2009 ES1, 2014 EIR2 and 2015 EIR3 considered a range of environmental topics: air quality; noise and vibration; landscape and visual amenity; ecology; water quality; geology, hydrology and land contamination; traffic and infrastructure; cultural heritage; and socio-economics. Supporting reports also included demonstration that the scheme met the Carbon Capture Readiness requirements.
The previous 1,800 MW CCGT-only scheme option assessed in the 2015 EIR comprised either a single shaft or a multi-shaft combined cycle arrangement with up to three gas turbines, each with a heat recovery steam generator (HRSG), and connected to either a dedicated steam turbine or a single steam turbine respectively, depending on plant configuration. Taking account of the implementation of the identified mitigation measures (which are required by the Section 90 Direction planning conditions), the 2015 EIR3 did not identify any significant adverse effects due to the construction or operation of the 1,800 MW CCGT-only scheme option, with the exception of moderate adverse effects on two nearby visual receptors. This conclusion was consistent with the findings of the 2009 ES1 and 2014 EIR2. The potential configuration considered for the proposed 1,800 MW CCGT with peaking plant scheme option (used in the plant visualisation (Figure 8), photomontages (Appendix G) and consideration of Carbon Capture and Storage Readiness (CCR) space requirements (Appendix B and Appendix C)) is a multi-shaft arrangement for the CCGT units, comprising two gas turbines, each with a HRSG, and
1 ScottishPower (2009) Damhead Creek 2 CCGT Power Station - Environmental Statement. 2 ScottishPower (2014) Damhead Creek 2 CCGT Power Station - Environmental Information Report. 3 ScottishPower (2015) Damhead Creek 2 CCGT Power Station - Environmental Information Report.
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connected to a single steam turbine. The peaking plant capacity will be generated through up to two OCGT units which will be natural gas fired with no diesel back-up.
The environmental appraisal has considered the General Arrangement Plan (2016) (Figure 4b) which is unchanged from the 1,800 MW CCGT-only scheme option (Figure 4a) considered in the 2015 EIR (whilst the detailed layout has changed to include the peaking plant, the development areas required remain unchanged).
Discusssions have taken place with DECC, Medway Council, the Environment Agency and Natural England on the proposed Section 36 Consent variation and their comments have been taken into account. Using available information, including additional environmental baseline data gathered since the 2009 ES was prepared; the predicted environmental effects of the proposed 1,800 MW CCGT with peaking plant scheme option have been compared to the environmental effects of the currently consented 1,800 MW CCGT-only scheme option. The findings are summarised below.
• Air Quality
o A dispersion modelling assessment has been undertaken for the proposed 1,800 MW CCGT with peaking plant scheme option to assess the potential effects on residential and ecological receptors in the vicinity of the Site. Agreement was reached with Natural England for the previous section 36 consent variation on the predicted level of impact on the designated ecological receptors – notably the Medway Estuary and Marshes SSSI, SPA and Ramsar site – that would not give rise to significant effects and the current proposed variation remains within those agreed levels.
o Through use of appropriate stack heights on the CCGT and OCGT units, no significant adverse air quality effects are predicted on human or ecological receptors as a result of the proposed variation, assuming emission levels remain within those to be specified within the Environmental Permit for the installation.
• Noise and Vibration
o A noise modelling assessment has been undertaken for the proposed 1,800 MW CCGT with peaking plant scheme option. The appraisal of noise and vibration effects has included consideration of residential and ecological receptors, including the Medway Estuary and Marshes SSSI, SPA and Ramsar site.
o No significant noise and vibration effects are anticipated with the mitigation proposed. Measures will include restrictions on construction working hours, daily as well as seasonal restrictions on impact piling, measures to reduce noise at source (including attenuation of key parts of the OCGT plant, incuding gas inlet) and noise monitoring in accordance with the previously agreed Noise Management and Monitoring Plan (NMMP) approved by the Council on 12 April 2013 under planning reference MC/13/0162 to demonstrate adherence to agreed noise limits at defined monitoring locations.
• Landscape and Visual Amenity
o The landscape and visual appraisal has been informed by revised photomontages for the eight representative viewpoints assessed previously.
o No changes to the conclusions of the previous assessment have been identified. The approved Landscape and Habitat Management Plan (ScottishPower, 2013b) will be reviewed and updated as necessary to accommodate the proposed 1,800 MW CCGT with peaking plant scheme option.
• Ecology
o The footprint of the proposed 1,800 MW CCGT with peaking plant scheme option will remain comparable to the CCGT-only scheme option. The appraisal of ecological effects therefore concludes that the 1,800 MW CCGT with peaking plant scheme option will not have any more significant effects on the designated site or any other ecological receptors to those predicted for the 1,800 MW CCGT-only scheme option, already approved.
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o Mitigation measures will be implemented during design, construction and operation, including use of stack heights sufficient to avoid significant adverse air quality effects on designated sites, and the implementation of the agreed Construction Environmental Management Plan (CEMP) approved by Medway Council on 23 December 2015 under planning reference MC/15/4047, use of appropriate noise mitigation and the agreed NMMP, and implementation of the approved Landscape and Habitat Management Plan (approved on 4 February 2014 pursuantto planning reference MC/13/3309) incorporating ecological enhancements.
• Water Quality
o No significant changes to the quality or quantity of liquid discharges are anticipated during construction and operation of the proposed 1,800 MW CCGT with peaking plant scheme option. The principles of drainage for DHC2 have previously been approved by Medway Council and will be adopted in the detailed design of this proposed option, in consultation with the Environment Agency.
o Mitigation measures will be implemented to minimise the risk of accidental pollution including use of the CEMP, appropriate bunding of any oil storage tanks and use of oil interceptors where necessary in the drainage system.
o In conclusion, no significant effects are predicted for the proposed 1,800 MW CCGT with peaking plant scheme option, as was the case for the currently consented 1,800 MW CCGT- only scheme option.
• Geology, Hydrology and Land Contamination
o The assessment concludes that there is no change to the previous 2015 EIR conclusions with regards geology, hydrology (including flood risk) and land contamination.
• Traffic and Infrastructure
o The proposed 1,800 MW CCGT with peaking plant scheme option will not require significant changes to the construction programme, number of construction staff and associated traffic, although the overall construction programme length may increase. The OCGT units are expected to be constructed in series with the CCGT units, rather than at the same time. Although the duration could therefore increase, the levels of workforce and traffic accessing the site each day or week are unlikely to increase. As a result, the conclusion of the construction phase assessment remains as for the 1,800 MW CCGT-only scheme option, with no significant adverse effects on the local road network predicted, with the exception of potential occasional short term disruption and delays caused by a small number of abnormal loads. To mitigate any such disruption, deliveries of such loads will be planned in consultation with the relevant authorities.
o During operation, the proposed 1,800 MW CCGT with peaking plant scheme option will not require any additional staff compared to the 1,800 MW CCGT-only scheme option, so no changes to the assessment of operational traffic impacts are anticipated.
• Cultural Heritage
o Archaeological surveys have been undertaken since the original Section 36 Consent was granted, demonstrating that the only areas of potentially significant archaeological interest are in localised northern and south-eastern parts of Area 1. ScottishPower are working to discharge of conditions 45 and 46 to the satisfaction of Kent County Council Archaeology and Medway Council by arranging for a suitable additional core sample to be taken from the northern area of interest, undertaking the appropriate reporting and updating the historical records sought by the regulators. Condition 47 was previously reworded to ensure that any potentially significant finds in this area during construction are notified to the Council, and an appropriate course of action is agreed.
o Overall the conclusions of the previous assessment and mitigation measures proposed remain unchanged from the previously consented scheme.
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• Socio-Economics
o The construction of the proposed 1,800 MW CCGT with peaking plant scheme option will require the same numbers staff as the 1,800 MW CCGT-only scheme option, although the duration of the construction programme may increase depending on the construction strategy to be adopted. The total investment in the proposed new option would be similar to that of the currently consented 1,800 MW CCGT (approximately £600 - £750 million) and still represents a substantial investment for the region. Therefore the conclusions of the previous assessment remain unchanged.
o There is no change to the socio-economic assessment of the operational phase as there is no anticipated change to the predicted number of operational and maintenance staff volumes.
In summary, the conclusions of the environmental assessment remain substantially unchanged and no additional significant effects have been identified associated with the proposed new scheme option.
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1. Introduction
ScottishPower (DCL) Limited (‘ScottishPower’) proposes to construct and operate a power station of up to 1,800 MW electrical output capacity, comprising a Combined Cycle Gas Turbine (CCGT) plant, and potentially also including Open Cycle Gas Turbine (OCGT) peaking plant, together called Damhead Creek 2 (DHC2) power station, on land immediately adjacent to their existing Damhead Creek CCGT power station on the Hoo Peninsula, Kent (National Grid Reference 581250, 172830). The location of the site is shown on Figure 1, the application site boundary is shown on Figure 2 and an aerial photograph of the site is provided on Figure 3. Figures are provided at the end of this report.
As part of the Iberdrola Group since April 2007, ScottishPower is one of the UK’s largest energy companies employing more than 8,000 people across generation, transmission, distribution and retail sectors.
ScottishPower generation business produces circa 16 TWh of electricity each year; the transmission and distribution business owns and operates a transmission and distribution network to around 3.3 million customers; whilst the retail business supplies gas and electricity to over 5 million customers. Today, as part of the Iberdrola group of companies, ScottishPower is also a world leader in renewable energy and the fifth largest electricity company in the world. The sister company ScottishPower Renewables, is the UK's largest developer of onshore wind farms with over 50 wind farms fully operational, under construction or in planning.
Consent under Section 36 of the Electricity Act 19894 and deemed planning permission was granted for DHC2 in January 2011 for the construction and operation of a 1,000 MW CCGT power station (“the 1,000 MW scheme”) adjacent to the existing Damhead Creek CCGT Power Station. Subsequently, ScottishPower has progressed with the discharge of planning conditions associated with that consent and with the detailed design of DHC2 and, as a result of changes made to the proposals during this process plus advancing turbine technologies, the Section 36 Consent has been varied to accommodate a larger capacity power station. The currently consented development comprises the construction and operation of a 1,800 MW CCGT power station (the ‘1,800 MW CCGT-only scheme option’).
Subsequent to obtaining consent for this 1,800 MW (ISO) scheme in October 2015, ScottishPower has identified the potential need to further develop the proposals and seek to vary the consent to allow for a combination of CCGT and OCGT generation at the Site. This is in order to respond to market demand for fast response electricity generation to grid to support renewables deployment in the UK (DECC, 2014)5. The proposed development therefore now comprises a CCGT plant and potentially an OCGT peaking plant located on the same Site; the peaking plant would have an electrical output capacity of up to 300 MW but the combined electrical output from the CCGT and OCGT will not exceed the 1,800 MW capacity (this option is hereafter referred to as the ‘proposed 1,800 MW CCGT with peaking plant scheme option’). A variation to the current Section 36 Consent is now being sought from the Department of Energy and Climate Change (DECC) pursuant to The Electricity Generating Stations (Variation of Consents) (England and Wales) Regulations 20136. This variation application retains the option of constructing the already consented 1,800 MW CCGT plant but also includes provision for up to 300 MW OCGT as part of that capacity, with the CCGT capacity correspondingly reduced such that the combined output remains at 1,800 MW (ISO). This Environmental Information Report therefore focuses on the new variant including the use of peaking plant, as the already consented CCGT-only option was fully assessed as part of the 2015 variation.
The planning history of DHC2 is described in more detail in Section 1.2.
4 UK Government, Electricity Act 1989 for Generating Stations in England and Wales. The Stationary Office (TSO), London 5 Department for Energy and Climate Change (DECC) (2014), Finalised Policy Positions for Implementation of Electricity Market Reform. The Stationary Office (TSO), London. 6 Department for Energy and Climate Change (DECC) (2013) Varying Consents Granted Under Section 36 of the Electricity Act 1989 for Generating Stations in England and Wales. The Stationary Office (TSO), London.
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1.1 Purpose of this Document The original Section 36 application was supported by an Environmental Statement (ES)7 (the ‘2009 ES’), and the applications to vary it were supported by Environmental Information Reports (EIRs) ( the ‘2014 EIR’8 and the ‘2015 EIR’9). This EIR provides an environmental review of the proposed 1,800 MW CCGT with peaking plant scheme option in the context of the information and findings of the 2009 ES, the 2014 EIR and the 2015 EIR and should be read in conjunction these documents.
Changes to the current consented scheme are detailed in Section 2 and appraised in Section 6. Appendix A sets out the proposed changes to the current Section 36 Consent. 1.2 Planning History of DHC2 The existing 793 MW Damhead Creek CCGT Power Station is owned and operated by ScottishPower, and has been successfully operating since it was commissioned in 2001.
Consent under Section 36 of the Electricity Act 19894 (the ‘1989 Act’) (the ‘Section 36 Consent’) and deemed planning permission (the ‘Section 90 Direction’) was granted for DHC2 on 25th January 2011 for the development, construction and operation of a new 1,000 MW CCGT power station. The Section 36 application was accompanied by the 2009 ES7.
Consent to increase the output to 1,098 MW was granted by DECC on 16th July 2012. A revised Carbon Capture Readiness report with regard to the 1,098 MW CCGT was accepted and approved by DECC in March 2013.
On 12th July 2013 ScottishPower secured planning permission from Medway Council under reference MC/12/2356 allowing the change of use of part of an existing wildlife creation area (WCA), which had been provided in accordance with a Section 106 obligation associated with the construction of the now operational Damhead Creek CCGT Power Station. The need for the change of use emerged through the detailed design process in order to accommodate the construction of the larger DHC2 footprint.
To compensate for the loss of part of the WCA, some land previously set aside to enable ScottishPower to meet its obligations for Carbon Capture and forming part of the area known as Area 3 (see Section 2.3) was designated as a new ecological mitigation area. This was designed to provide the replacement of all habitat types from the former WCA at a ratio no less than 1:1.2, and providing suitable enhancement where possible. The new ecological mitigation area was designed to maximise the quality and connectivity of the habitats throughout the entire ScottishPower landholding. The planning permission for change of use was secured, following detailed discussions with Natural England, the Environment Agency, Medway Council, and Kent County Council.
In late 2013, as the result of discussions with Original Equipment Manufacturers (OEMs), it became apparent that the output of DHC2 could be increased to around 1,200 MW of electrical output capacity at site rated conditions. A variation to the Section 36 Consent was sought from DECC, pursuant to the Electricity Generating Stations6 (Variation of Consents) (England and Wales) Regulations 2013, which came into force in July 2013. Consent to construct and operate the 1,200 MW (ISO) scheme was granted in July 2014 (reference 12.04.09.04/265C).
Following the first Capacity Market Auction under the Electricity Market Reform mechanism in December 2014 ScottishPower, through ongoing discussions with OEMs decided that the ongoing development of turbine technologies would enable development of a plant with a power generation capacity of up to 1,800 MW to be possible at the Site and would ‘future proof’ the DHC2 scheme. This is the optimum capacity that can be accommodated in the available space whilst still retaining sufficient land for future carbon capture and storage (CCS) obligations, and is the single maximum capacity event that National Grid Electricity Transmission (NGET) will permit on the grid network. A variation to the Section 36 Consent was sought from DECC, pursuant to the Electricity Generating Stations (Variation of Consents)
7 ScottishPower (2009) Damhead Creek 2 CCGT Power Station - Environmental Statement. 8 ScottishPower (2014) Damhead Creek 2 CCGT Power Station - Environmental Information Report. 9 ScottishPower (2015) Damhead Creek 2 CCGT Power Station - Environmental Information Report.
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(England and Wales) Regulations 20136. Consent to construct and operate the 1,800 MW CCGT-only scheme option was granted by DECC on 23rd October 2015.
Since the original Section 36 Consent and associated Section 90 Direction under the Town and Country Planning Act 199010 for DHC2 was granted in 2011, ScottishPower has been working to discharge the planning conditions in the Section 90 Direction. The discharged planning conditions are listed as follows and are referenced within the relevant environmental topics in Section 6:
• Planning condition 7 relating to layout and design;
• Planning condition 10 relating to the Green Travel Plan;
• Planning conditions 11 and 18 relating to Construction Environment Management Plan and Construction Traffic Management Plan;
• Planning conditions 20 and 21 relating to operational noise;
• Planning conditions 26 relating to the prevention of contamination of watercourses;
• Planning conditions 42, 43 and 44 relating to biodiversity enhancement measures and protection of water voles;
• Planning conditions 32, 33, 34 and 35 relating to contaminated waste;
• Planning conditions 38, 39, 40 and 41 relating to landscaping and creative conservation;
• Planning condition 48 relating to water efficiency measures; and
• Planning condition 55 relating to stack lighting.
In addition planning conditions 3, 4, 5 and 6 of the planning permission MC/12/2356 relating to the consent for the change of use of the former WCA have been discharged.
Further detail on the pre-commencement planning conditions is included within Section 4. 1.3 Environmental Assessment The findings of the 2009 ES, 2014 EIR and 2015 EIR are summarised below: 1.3.1 Air Quality No significant impacts on air quality were predicted during construction of the pproposed power station, nevertheless, condition 11 of the Section 90 Direction required the preparation and implementation of a Construction Environmental Management Plan (CEMP) including measures to control dust and other airborne pollutants. The CEMP has been submitted to and approved by Medway Council under reference MC/15/4047.
Operational emissions from DHC2 at the same time as emissions from the existing Damhead Creek power station were not predicted to have a significant effect on local air quality or lead to an exceedance of any of the UK Air Quality Strategy (AQS) objectives11. In addition, there were no predictions in excess of the thresholds of significance derived from Environment Agency Horizontal Guidance Note H112. No significant impacts on identified residential receptors were identified.
Additional consideration has been given to impacts on the adjacent Medway Estuary and Marshes SSSI, SPA and Ramsar site and consultation with both the Environment Agency and Natural England concluded that final stack heights were to be determined to ensure that emissions did not lead to exceedances of the annual Critical Levels for the Protection of Ecosystems, nor exceed the lower end of the critical load range for nitrogen deposition within the SSSI, when in combination with background
10 UK Government, Town and Country Planning Act 1990. The Stationary Office (TSO), London 11 HM Government (2000) Air Quality (England) Regulations 2000, HMSO, London. 12 Environment Agency (2012) Horizontal Guidance Note H1. Environment Agency, Bristol.
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concentrations. It was therefore concluded that during normal commercial operations, on the basis of the proposed design and stack heights, DHC2 would not have a significant impact on air quality with regard to short or long term ground level concentrations of nitrogen dioxide (NO2) or any other pollutant. 1.3.2 Noise and Vibration Noise levels during construction were predicted not to exceed the Department of Environment guideline level for residential receptors of 70dB(A) at the closest residential property (located just under 500 m from the boundary of the construction site), and as such no significant effects were predicted. Noise emissions during construction will be subject to the planning requirements set out in conditions 11, 12, 14, 15 and 16. The results of noise modelling indicated there would be no significant noise effect during normal operation of the power station. A Noise Monitoring and Management Plan (NMMP)13 was approved by Medway Council on 12th April 2013 and the 2015 EIR concluded that the noise levels from the 1,800 MW CCGT-only scheme option would still be compliant with this Plan. No significant vibration effects were identified during construction or operational use. 1.3.3 Landscape and Visual The landscape and visual assessment concluded that there would be no significant effects on landscape character and that only two of the eight viewpoints analysed would undergo moderate adverse (significant) visual effects. Both viewpoints were representative of relatively close range receptors situated on the higher ground to the north of the DHC2 site, but no additional mitigation measures were considered necessary to mitigate the effects. The 2015 EIR concluded that the approved Landscape and Habitat Management Plan14 was to be reviewed and updated as necessary to accommodate the proposed 1,800 MW CCGT-only scheme option. 1.3.4 Ecology The ES identified the following potentially significant adverse effects on ecological receptors during construction (if no mitigation was applied):
• potential for significant effect at international level on Medway Estuary and Marshes Site of Special Scientific Interest (SSSI)/ Special Protection Areas (SPA)/ Ramsar site due to the risk of pollution and disturbance;
• significant effects at county level on habitat features (i.e. waterbodies) due to the loss of ponds within the site;
• significant effects at county level on barn owl and marsh harrier due to loss of foraging habitat, disturbance and risk of mortality on site;
• significant effects at district level on water vole due to habitat fragmentation, and on reptiles due to habitat loss, disturbance and risk of mortality on site; and
• significant effects at local level on badgers due to impacts on commuting and risk of mortality on site, on bats due to loss of foraging habitat (ponds) and likely commuting corridors and temporary site lighting, on amphibians due to disturbance and the risk of mortality, on terrestrial invertebrates due to disturbance and the risk of mortality, and on aquatic invertebrates due to habitat loss, disturbance and the risk of mortality.
Measures approved by the Council under conditions 42, 43 and 44 will mitigate these effects by protecting fauna and enhancing habitats on site in the long term.
No significant operational effects were identified.
13 ScottishPower (2013) Revised Noise Limits and Noise Monitoring & Management Plan. 14 ScottishPower (2013) Landscaping and Creative Conservation
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The 2015 EIR identified that although the larger footprint of the proposed 1,800 MW CCGT-only scheme option would bring the development closer to the Medway Estuary and Marshes SSSI, SPA and Ramsar site, but would not have any increased significant effects on the designated site or any other ecological receptors to those previously predicted. The 2015 EIR concluded that the approved Landscape and Habitat Management Plan16 was to be reviewed and updated as necessary as part of the detailed design. 1.3.5 Water Quality No significant effects on water quality were predicted, either during construction or operational use. The reports submitted and approved in accordance with planning condition 26 will ensure the detailed design of site drainage will be appropriate to prevent pollution.
The 2015 EIR also identified that the principles of drainage for DHC2 had been approved by Medway Council and would be adopted in the detailed design of the proposed 1,800 MW CCGT-only scheme option, in consultation with the Environment Agency. An Addendum to the proposed drainage scheme was submitted to Medway Council for approval in December 2015 providing additional information in respect of the proposals to prevent the contamination of watercourses. At the present time the application to discharge this condition is awaiting determination. 1.3.6 Geology, Hydrology and Land Contamination No significant effects on soils and geology were predicted during construction, as it was concluded that any impacts would be mainly confined to made ground and river deposits just below the subsurface and would be limited to localised, temporary erosion and compaction impacts caused by earthworks and vehicular movements. These conclusions have been reaffirmed by further site investigation work undertaken pursuant to conditions 32 to 35. The 2015 EIR also noted that a number of guidance documents and standards have been revised since the last assessment and would be adhered to as appropriate.
No significant operational effects were identified. 1.3.7 Traffic and Infrastructure No significant effects were predicted based on the expected volume of construction traffic. However, it was concluded that, unless properly managed, the transport of abnormal loads could lead to short term disruption or delays with significant short term effects on the local highway network. The 2015 EIR stated that abnormal loads would be planned in consultation with the relevant authorities to minimise disruption to other road users.
A Green Travel Plan (GTP) and Construction Traffic Management Plan (TMP) has been prepared and submitted to Medway Council in accordance with conditions 10 and 18 of the Section 90 Direction. The GTP was approved under planning reference MC/15/3907 and the TMP approved under reference MC/15/4047 on 18th December and 23rd December 2015 respectively.
These assessments concluded that subject to the proposed mitigation measures being implemented, neither construction nor operational traffic would result in a significant effect on the local road network. 1.3.8 Cultural Heritage No significant effects on cultural heritage resources were identified as a result of construction or operation.
At the time of writing the 2015 EIR, archaeological surveys had been undertaken on behalf of ScottishPower. This identified that the only areas of potentially significant archaeological interest are in the northern and south-eastern parts of Area 1.
ScottishPower are working to discharge of conditions 45 and 46 to the satisfaction of Kent County Council Archaeology and Medway Council by arranging for a suitable additional core sample to be taken from the northern area of interest, undertaking the appropriate reporting and updating the historical records sought by the regulators. Condition 47 was previously reworded to ensure that any potentially
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significant finds in this area during construction are notified to the Council, and an appropriate course of action is agreed.
The 2015 EIR concluded that overall the conclusions of the previous assessments and mitigation measures proposed remain unchanged. 1.3.9 Socio- Economics The construction of DHC2 was predicted to have a significant beneficial effect on local businesses. No significant adverse effects on tourism were predicted during construction. In addition, the 2015 EIR concluded that although the overall the conclusions remain unchanged the 1,800 MW CCGT-only scheme option would result in more beneficial socio-economic effects including employment of local people and sourcing of local goods, services and contractors, and indirect employment benefits.
No significant operational effects were identified.
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2. Description of the Development
2.1 Proposed Development The proposed development is the construction and operation of a gas fired power station of electrical output capacity up to 1,800 MW adjacent to the existing Damhead Creek CCGT Power Station site located on the southern side of the Hoo Peninsula, to the east of Chatham and Rochester. The plant would be fired on natural gas from the UK National Transmission network; no back-up firing on distillate fuel is proposed. As with the existing Damhead Creek CCGT, the plant will be air cooled. The power station will comprise a CCGT plant of up to 1800 MW or potentially a CCGT and an OCGT peaking plant located on the same Development Site; the peaking plant would have an electrical output capacity of up to 300 MW but the combined electrical output from the CCGT and OCGT will not exceed the 1,800 MW capacity.
It is expected that DHC2 will operate in various running modes including full load (maximum continuous rating) and two shifting where the plant can be switched on and off during the day to meet peak demands. The plant will occasionally be shut down for periods of essential maintenance and statutory inspections. DHC2 is expected to have an annual availability of the order of 93% with the remainder of the time dedicated to annual maintenance and unplanned plant failures. The operational lifetime of the development will be of the order of 35 years. It is envisaged that the peaking plant will operate for up to 1,500 hours per year, to respond to peak demand on the UK transmission system although the CCGT units are expected to run at higher load factors for the early years of operation with up to 80% expected, reducing significantly over time as more renewable energy comes on-line.
The previously consented 1,800 MW scheme comprised either a single shaft or a multi-shaft combined cycle arrangement with up to three gas turbines, each with a HRSG, and connected to either a dedicated steam turbine or a single steam turbine respectively, depending on the plant configuration. The total electrical output was 1,800 MW at ISO conditions. For this assessment, a multi-shaft arrangement has been considered for the CCGT units, comprising two gas turbines, each with a HRSG, and connected to a single steam turbine. This is to allow sufficient space for the peaking plant to be accommodated within the Site footprint without comprising the space to be retained for the CCR land. The peaking plant capacity will be generated through up to two OCGTs which will be gas fired with no diesel back-up. As previously stated, ScottishPower wish to retain the scheme layout options already consented under the 2015 variation, and this application is therefore to add a new option of including up to 300 MW OCGT peaking plant within the total consented 1,800 MW output.
The previously assessed 1,800 MW scheme would have operated in combined cycle mode with an overall electrical generation efficiency conservatively estimated at up to 59.5% based on the lower calorific value (LCV) of the fuel, which would be similar for the proposed CCGT units in this application. Additional thermal efficiency gains might be capable of being achieved if it were to become technically and economically feasible to provide heat and/or power to surrounding facilities/ customers on a Combined Heat and Power (CHP) basis, but no such schemes have been identified to date. The peaking plant typically operates at a lower electrical generation efficiency – of around 34% - as there is no heat recovery at the outlet of the gas turbines. This is because the peaking plant needs to operate in a fast response mode to be able to ramp up to meet any shortfall in generation on the UK grid as quickly as possible, and open cycle units can achieve full output in around 45 minutes (warm start-up) as opposed to around 96 minutes for a CCGT. The General Arrangement Plan (2016) (Figure 4b) is based on this arrangement of the multi shaft CCGT and up to two peaking plant units, and is unchanged from the 1,800 MW CCGT-only scheme option (Figure 4a) considered in the 2015 EIR in terms of land areas required for each part of the proposed development.
The total electrical output of the proposed development would therefore be up to 1,800 MW at ISO conditions.
Both the currently consented 1,800 MW CCGT-only scheme option and the proposed 1,800 MW CCGT with peaking plant scheme option would export the electricity generated to the National Grid via the existing Kingsnorth 400 kV substation, which lies approximately 500 m to the south of the existing Damhead Creek CCGT Power Station boundary.
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DHC2 is also being designed as Combined Heat and Power (CHP) ready and this is discussed in Section 2.8. 2.2 Site Location The Damhead Creek CCGT Power Station site, which is owned and operated by ScottishPower (DCL) Ltd., is located on the southern side of the Hoo Peninsula, to the east of Chatham and Rochester. The site lies to the north of the Medway River within the historic parish of Hoo St. Werburgh and the administrative district of Medway Council, 3 km south-east of the A228 and 9 km north-east of Rochester and Chatham (National Grid Reference 581250, 172830) (see Figure 1). The area of land which is to be developed for the proposed development (the ‘application site’) is adjacent to the existing Damhead Creek CCGT Power Station. The application site is generally flat, low- lying and predominantly open ground, at an average height of approximately 3.2 m above the Ordnance Datum (AOD). The surrounding land comprises: undeveloped land to the north; Damhead Creek (a tidal estuary of the River Medway) to the east; agricultural land and the former Kingsnorth Power Station to the south; and Damhead Creek power station and the Kingsnorth Industrial Estate to the west. The application site is shown edged red on Figures 2, 3, 4a and 5. The application site boundary has not been altered since the Section 36 Consent was granted in 2011. 2.3 Application Site Context The application site is described as three main areas (see Figure 2):
• Area 1 is where the majority of the new DHC2 will be constructed and lies to the east of the existing Damhead Creek CCGT Power Station (also referred to as the ‘triangle site’). The area is low-lying undulating ground sloping to the south-east and comprises unmanaged grassland and some hardstanding. Area 1 was largely topsoil-stripped and disturbed during the construction of existing Damhead Creek CCGT Power Station;
• Area 2 lies to the north of the existing Damhead Creek CCGT Power Station and was originally going to house a substation. This land consists of hardstanding and is not currently in use; and
• Area 3 lies to the north-east of the existing Damhead Creek CCGT Power Station. All land in Area 3 has previously been used to dispose of the fly ash from the nearby Kingsnorth Power Station. It is surrounded on the south-west by the ecological mitigation area associated with the existing Damhead Creek CCGT Power Station.
The general arrangement plan for the proposed 1,800 MW CCGT with peaking plant scheme option is the same as that considered for the 1,800 MW CCGT-only scheme option in the 2015 EIR. The general arrangement plan is presented in Figure 4b (based on the indicative layout as shown in Figure 5). Area 1 and part of Area 3 will be used for the CCGT and OCGT plants (total 10.4 ha). An updated Carbon Capture Readiness (CRR) Footprint Report is provided in Appendix B The full requirements for CCR land will be met using Area 2 and approximately 5 ha of land in Area 3. Although the exact layout is yet to be determined, it has been confirmed that this layout is achievable. The area of land set aside for CCR requirements has previously been validated by Imperial College for the 1,800 MW scheme and the same area is to be retained for the peaking plant option, which could potentially be for the capture of carbon from a 1,500 MW CCGT. The CCR validation report15 is included as part of the application to DECC. This is documented in Appendix C. 2.4 Main Buildings and Plant The design of buildings, enclosures and equipment will minimise regular and long term maintenance. Materials and finishes will be selected to meet this objective and to maintain the appearance of the proposed 1,800 MW CCGT with peaking plant scheme option over its operating lifetime (approximately 35 years). Materials and finishes will be similar to those used on the existing Damhead Creek CCGT Power Station, and the final details, surface finishes and materials have been agreed with Medway
15 Impreial College, (2016) Assessment of the CCR Compliance of the Proposed Damhead Creek 2 1500 MW CCGT + 300 MW OCGT Scheme, London
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Council through the submission and approval of the Design Report under planning reference MC/15/4047.
The indicative dimensions of the main items of plant for the 1,800 MW CCGT-only scheme option and for the proposed 1,800 MW CCGT with peaking plant scheme option differ slightly and are shown in Table 2.4.1.
Table 2.4.1: Indicative Plant Dimensions (Based on Figure 5) 1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option Component Option 2 Option 3 Single Shaft Multishaft
Stacks (H x D) 3 stacks modelled at up 3 stacks modelled at up to 2 peaking plant stacks modelled at to 95 m height x approx. 95 m height x approx. 11 m up to 50 m height x approx. 8.4 m 11 m external diameter external diameter external diameter 2 HRSG stacks modelled at up to 95 m height x approx. 8.4 m external diameter
Turbine hall (L x W x H) 3 turbine halls each 1 gas turbine building approx. 2 gas turbine buildings 72m x 31m x approx. 80 m x 30 m x 120 m x 20 m x 25 m 30m* 25 m 1 steam turbine building 1 steam turbine building 60m x 30m approx. 65 m x 35 m x 25 m x 25m*
HRSG enclosure (L x W x 3 HRSG buildings each 3 HRSG buildings each 1 HRSG building approx. 36 m x H) approx. 30 m x 25 m x approx. 35 m x 40 m x 45 m 34 m x 45 m* 45 m
Air Cooled Condenser (L 3 units each approx. 1 unit approx. 125 m x 125 m x 1 units approx. 84m x 135m x 46.5m x W x H) 10 m x 80 m x 50 m 50 m
Peaking plant GT Building n/a n/a 1 building 84m x 30m x 20m* (L x W x H)
Peaking plant fin fan n/a n/a 4 sets of fans 12m x 11m x 7m coolers (L x W x H)
*The use of enclosures has been assumed for the purposes of noise modelling but the requirement for buildings or other enclosures will be determined based on the final design and selection of equipment in order to achieve the noise limits set for the proposed development.
The exact dimensions for the proposed 1,800 MW CCGT with peaking plant scheme option and building requirements will be confirmed at the detailed design stage and will be agreed with Medway Council prior to the commencement of construction. The above dimensions however represent the likely sizes of the main components based on ScottishPower’s discussions with OEMs. 2.5 Process Description The process for both the currently consented 1,800 MW CCGT-only scheme and the proposed 1,800 MW CCGT with peaking plant scheme is largely the same and is described below.
The use of CCGT is considered a Best Available Technique (BAT) for baseload electricity generation from natural gas as they have a high efficiency. The energy conversion in the gas turbine is very effective in using relatively hot gases in the turbine, when compared to other types of power stations (e.g. conventional power stations, simple cycle gas turbines). However, use of open cycle gas turbines can represent BAT for the provision of fast response, short term peak electricity to meet the demands of the UK electricity network, since such demands are triggered over short timescales and gas is a cleaner fuel than diesel, which is the alternative fuel for peaking plant.
The gas turbines will burn natural gas in a combustion chamber from where the hot combustion gases expand through the gas turbine, which in turn drives an electrical generator to generate electricity. The hot exhaust gases still contain recoverable energy and will therefore be used in the HRSGs in the CCGT units to generate steam. The high-pressure steam produced will be used to drive steam turbine equipment to generate additional electricity.
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The spent steam leaving the steam turbine equipment will be condensed (via the air cooled condenser) and the resultant condensate returned to the HRSGs for re-use. The use of an air cooled condenser means that there is no need for cooling towers or a once-through cooling water system, thereby eliminating potential environmental impacts associated with such water based systems, which may have included a visible plume from a cooling tower and would have required abstraction from, and discharge to, a local watercourse. For the open cycle units, no cooling of steam is required and the hot gases vent straight to atmosphere via the dedicated stacks.
The steam turbine system will comprise the turbine itself, a multi-cell air cooled condenser and condensate extraction pumps and air extraction equipment. Each gas turbine will comprise an inlet air filter, an air compressor, combustion chamber, power turbine and exhaust sections. The gas turbines chosen for installation at DHC2 will be equipped with proven primary pollution control technology (dry low-NOx (DLN) burners), which will minimise the formation of oxides of nitrogen (NOx) to a maximum of 50 mg/Nm3 when gas turbine outputs are above 70% in accordance with the limits set in the Industrial Emissions Directive (IED)16. Use of DLN burners represents BAT for limiting emissions of NOx to atmosphere from gas turbines. Natural gas is a clean fuel and does not produce the particulate emissions associated with burning coal; consequently, post-combustion flue gas cleaning equipment is not required for particulate control. State- of-the-art combustion control systems will be used, enabling combustion to be optimised for all operating conditions.
The gas turbines will be situated inside integral acoustic enclosures designed to ensure that noise levels generated by the plant are within agreed limits at the off-site monitoring points. The exhaust gases from each CCGT unit will be discharged to atmosphere via a dedicated stack, not expected to exceed 95 m height and up to 8.4 m diameter (with an external diameter of 11 m). The peaking plant stacks will be approximately 50 m in height and narrower diameter than the CCGT stacks. The height of the stacks will be finalised at the detailed design stage and informed by a dispersion modelling study (see Appendix D) to ensure predicted impacts at sensitive residential, amenity and ecological receptors are at levels that are acceptable to the Environment Agency and Natural England. There will be no bypass stacks installed.
The key challenge in natural gas combustion systems is to control the formation of nitrogen oxides, specifically thermal NOx that is generated with increasing firing temperature. Gas turbine technology strives to increase flame temperature, so as to increase cycle efficiency. This therefore causes higher NOx production that needs to be mitigated through advances in combustion system technology.
As outlined above, the gas turbines will be fitted with advanced DLN burners. These may feature pre- mixed combustion systems including techniques such as fuel staging to control parameters such as flame residence time, fuel-to-air ratio and firing temperature in order to minimise the formation of thermal NOx.
The gas turbines may be subject to periodic compressor washing to clean the compressor or blades which gradually become dirty (as a result of airborne particulates adhering to their surfaces) and therefore less efficient. The types and frequency of compressor washing will depend on the site atmospheric conditions. Typically, there will be two off-line water washes per year, with on-line water washing carried out on daily basis.
There will be one start up boiler on site, which will operate on natural gas fuel only, and will be used for start-up and shutdown purposes. Steam from the boiler is used during start up to heat incoming gas and seal steam turbine glands. Once steam is available from the normal turbine and HRSG operation, the start-up boiler will cease to be used. Storage for chemicals will be provided in appropriately bunded and secure areas within the existing Damhead Creek CCGT Power Station (DHC1) on site stores.
16 European Commission (2001) Council Directive on the Limitation of Emissions of Certain Pollutants in the Air from Large Combustion Plants (2001/80/EC). Official Journal of the European Union.
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Fire water will be stored in a new tank within the DHC2 site. DHC2 may also be connected to the existing Damhead Creek CCGT Power Station fire water tank, if necessary.
Demineralised water used in the water-steam cycle (i.e. the HRSGs and steam turbine) is anticipated to be produced by a new water treatment plant for DHC2 and stored in a demineralised water storage tank. The water treatment plant equipment will include pumps, ion-exchange vessels and storage vessels for chemicals used to condition the water and regenerate ion-exchange resins. The demineralised water supply systems for DHC1 and DHC2 may be interconnected to allow flexibility of supply, if necessary. As an alternative to constructing a DHC2-dedicated water treatment plant, it may be feasible to expand and upgrade the existing DHC1 water treatment plant in order to supply sufficient demineralised water to serve to needs of both the DHC1 and DHC2 plants, and the feasibility will be determined during the detailed design phase. The volume of water required for the proposed 1,800 MW CCGT with peaking plant scheme option will be proportionately less than for the currently consented 1,800 MW CCGT scheme (approximately 500 m3 per day compared to approximately 750 m3 per day), since only two CCGT units will be installed; the water demand of the open cycle units is negligible as there is no steam system. Transformers will be provided on site to allow the plant to receive electrical supplies from the wider National Grid and to supply electricity back to the system. All transformers will be oil-filled and sited within a containment bund that will be capable of containing 110% of the oil content of the transformer in the event of a spillage. Pumps will drain these sumps to an oil separator, which in turn will discharge to the existing Damhead Creek CCGT Power Station site drainage system. The sumps will be installed with high level alarms to avoid overflow.
The remainder of the proposed 1,800 MW CCGT with peaking plant scheme will consist of a natural gas reception facility, air compressing equipment, electrical switchgear and control equipment, closed cooling water system, and an effluent treatment system. Control facilities will be provided, as will fire- fighting services. Other ancillary buildings such as workshops, warehouses, security building office and welfare facilities will also be located on site.
One emergency diesel generator (EDG) will be installed, to provide emergency back-up and enable the proposed 1,800 MW CCGT with peaking plant scheme to be shut down in a safe manner in the event of loss of electricity. It is expected that the EDG will only ever be operated for testing purposes and only for very short durations. 2.6 Operational Information Operational information is largely the same for both the proposed 1,800 MW CCGT with peaking plant scheme option and the currently consented 1,800 MW CCGT-only scheme option, as follows.
DHC2 will burn natural gas only, which will be brought to the application site via the existing gas pipeline which connects the existing Damhead Creek CCGT Power Station to the National Transmission System. As the existing power station at Damhead Creek was built to allow for future expansion there is no need to install a new gas pipeline as the existing pipeline is of sufficient capacity to provide the gas needed by both plants. With the exception of temperature and pressure regulation, the natural gas will not be treated on site and accordingly natural gas will not be stored on site. The quality of the natural gas will be the same as that used in domestic properties and will be supplied to a flanged terminal point most likely in the northern area of the existing Damhead Creek CCGT Power Station site, at a pressure in the range of 30-70 bar(g). From this terminal point, the natural gas will be supplied via a new, dedicated gas receiving facility (GRF) for the proposed 1,800 MW scheme, which will be installed adjacent to the existing Damhead Creek CCGT Power Station GRF. This system will include provision of a duty and start-up gas feed system with each line incorporating gas filtration, a pressure let down station and gas heaters to supply gas at the required conditions to the proposed 1,800 MW CCGT with peaking plant scheme. The feed gas will then be preheated in the GT Fuel Gas Heaters prior to use in the gas turbines.
There will be gas pressure reduction or compression facilities on site to regulate the pressure of the incoming gas supply to that required by the gas turbines.
Lubricating oils will be used within the power station and will be stored on the existing Damhead Creek CCGT Power Station site in the oil storage building at the north east of the site, in an impermeable bund sized to contain 110% of the contents of each tank, in line with the Environmental Permitting
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requirements and the Control of Pollution (Oil Storage) (England) Regulations17. Each turbine will have its own lubricating system including above ground tank. Used lubricating oils will also be stored on the existing Damhead Creek CCGT Power Station site for re-use or will be disposed off-site by an approved and licensed contractor in accordance with applicable regulations. Storage facilities will also be provided for the small quantities of sodium phosphate, oxygen scavenger, ammonia and other chemicals used in boiler water dosing. All such chemicals will be retained in suitable containment areas within the site. Fugitive releases and breathing losses from the ammonia and oxygen scavenger dosing and dilution tanks will be passed through water seals or, if appropriate, carbon filters to minimise the release of these chemicals to the atmosphere. Miscellaneous materials such as oils, greases, cleaning substances and materials, laboratory chemicals etc., will be stored in suitable storage conditions or containers on the existing Damhead Creek CCGT Power Station site.
All storage facilities will be designed, situated and used in compliance with Control of Substances Hazardous to Health (COSHH) Regulations. Sewage effluent will be discharged via the existing sewerage system at the existing Damhead Creek CCGT Power Station site.
A compressed air system will be provided to compress and deliver the quantity and quality of air suitable for all general, instrument and control purposes for DHC2.
Plant performance will be continuously recorded to ensure optimal operation of DHC2. Any significant deviations will be alarmed and corrections carried out on occurrence. Records will be maintained of performance and deviation.
DHC2 will be designed to minimise waste disposal to landfill. The following waste streams may be disposed to landfill where it is not possible to recycle or return to the supplier:
• used gas turbine air intake filters (typically replaced annually);
• separated oil/ sludge from oil/ water separators;
• used oil or chemical containers; and
• general office waste.
The quality of process effluent will be monitored and discharges from the water treatment plant will be controlled by the Environmental Permit. The majority of boiler blowdown water will be reused by recycling through the water treatment plant. The total volume of water discharged from the water treatment plant and the surface water drainage system will be proportionately less for the proposed 1,800 MW CCGT with peaking plant scheme option compared to the currently consented 1,800 MW CCGT-only scheme option since only two CCGT units will be installed; there will not be significant effluent generation from the open cycle units.
Major plant maintenance shut downs will be planned on a long-term basis with intermediate stoppages being infrequent and of short duration only. 2.7 Environmental Permit ScottishPower currently operate the existing Damhead Creek CCGT Power Station under an Environmental Permit (ref. EPR/NP3634WE). In parallel with this Section 36 Consent variation for the proposed 1,800 MW CCGT with peaking plant scheme and in accordance with the Environmental Permitting Regulations (EPR) (England and Wales) 201018, ScottishPower have prepared, to be submitted in spring 2016, a variation to the extant Environmental Permit to account for changes in site activities brought about by the construction and operation of the consented 1,800 MW CCGT-only
17 UK Government, (2001), Control of Pollution (Oil Storage) (England) Regulations, HMSO, London 18 UK Government, (2010) The Environmental Permitting (England and Wales) Regulations 2010 (SO 2010 No. 676), as amended, HMSO, London
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scheme option. This permit variation will regulate activities associated with the operation of both power stations.
Should ScottishPower decide to progress with construction of the 1,800 MW CCGT with peaking plant scheme option, a further variation to the Environmental Permit will be applied for as appropriate. 2.8 Combined Heat and Power (CHP) The UK Government requires, as outlined in NPSs EN-119 and EN-220, that any proposals for new power projects sized greater than 50 megawatts electrical (MWe) should be accompanied by an assessment of the potential for CHP in the vicinity of a proposed development site. In addition, the Environment Agency requires that all applications for environmental permits for new installations regulated under the Environmental Permitting (England and Wales) Regulations 201020 demonstrate the use of BAT for a number of criteria, including energy efficiency. One of the principal ways in which energy efficiency can be improved is through the use of CHP. The Environment Agency stipulates that any new power station is demonstrated to be CHP Ready in accordance with the Environment Agency CHP-Readiness Guidance for Combustion and Energy from Waste Power Plants v1.0, dated February 201321.
To allow for the potential future use of CHP, the proposed DHC2 will incorporate suitable design modifications which will allow for export of heat in the event that a suitable user is identified. A CHP Readiness (CHP-R) Report for the proposed DHC2 1,800MW CCGT with peaking plant scheme option is included within Appendix E.
Medway Council has agreed to the revision of the obligation in the Section 106 Agreement entered into when the original Section 36 Consent was issued to install pipework to the site boundary during the plant construction for a potential, as yet undefined future CHP scheme. A deed of variation was agreed with Medway Council (September 2015) in that the necessary pipework and plant for CHP will be installed only when ScottishPower has entered into a contract with a third party for the supply of heat from DHC2; however this did not require any variation to the current CHP condition as set out at condition 52 of the Section 90 Direction.
A CHP Assessment was undertaken as part of the original Section 36 Consent application and submitted to DECC in support of that application. A CHP Readiness study has been undertaken to support the Environmental Permit application and a further assessement will be undertaken prior to the commissioning of DHC2 to discharge condition 52 of the Section 90 Direction.
The 2015 CHP Readiness study evaluated the feasibility of supplying heat generated during the electrical generation process to nearby customers. Key to this study was the evaluation of the demand for heat in the local area and the ability to provide a reliable supply during periods of plant operation and maintenance. The CHP Readiness study was undertaken in accordance with the requirements of the NPSs EN-121 and EN-222 and the Environmental Agency’s CHP Ready Guidance. This section draws upon the findings of the study and evaluates CHP readiness for the proposed 1,800 MW CCGT with peaking plant scheme option. 2.8.1 Potential Future Heat Users The current demand for heat within 15 km of the application site is considered to be currently too low and does not occur in sufficient density to enable a heat network to be technically or economically viable. Consultations with Medway Council from 2014 to late 2015 identified three potential future off-site users of heat from the proposed DHC2: Lodge Hill; Goodman International; and National Grid Site. These schemes are discussed below.
19 Department for Energy and Climate Change (2011) Overarching Energy National Policy Statement (EN-1). The Stationary Office (TSO), London. 20 Department for Energy and Climate Change (DECC) (2011) National Policy Statement for Fossil Fuel Electricity Generating Infrastructure (EN-2). The Stationary Office (TSO), London. 21 Environment Agency (2013) CHP-Readiness Guidance for Combustion and Energy from Waste Power Plans v1.0 (February 2013)
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Lodge Hill (also known as Chattenden Scheme)
Previous searches of future development in the area had identified the Lodge Hill scheme by Land Securities as being a major CHP opportunity in the area. This scheme, which was to be developed on behalf of the Ministry of Defence (MoD) planned to provide up to 5,000 dwellings and associated facilities, in a new development circa 6 km to the west of the DHC2 facility.
The developers of the site were contacted to determine the heating and energy strategy for the scheme, with anticipated peak (7 – 9 MWth) and base (1.5 – 3 MWth) thermal loads, estimated using information submitted as part of the outline proposal22, being consistent with the findings of a previous study undertaken in 2009 by Parsons Brinkerhoff23. The identification of this development was previously considered a key opportunity to provide a secure and high demand anchor load for a large district heat network for the area, with heat provided from the DHC2 site. Provision of a large anchor load like the Lodge Hill scheme would significantly improve the technical and economic feasibility of any district heat network.
However, a number of difficulties with the use of the Lodge Hill scheme were identified. These included confirmation from the developer that the construction of the scheme would be phased over 25 years, with approximately 150-200 residential units being completed per year. Such a long phasing programme represented a potential risk; the assessment indicates that only when the scheme was complete would the end user heat load be sufficient to make connection to a remote heat source such as DHC2 viable, both economically and environmentally. In addition to this, the significant infrastructure required to transport the heat from DHC2 to the proposed development site 6 km away, potentially impacts on the overall economic viability of connection.
AECOM has previously undertaken the above high-level review of the viability of this option.
In addition, the Lodge Hill scheme was challenged by Natural England due to the site’s partial designation as a Site of Special Scientific Interest (SSSI), with the application also being referred to the Secretary of State and the Medway Council.
Recent announcements24 confirm that Land Securities now no longer intends to develop the scheme and is pulling out of the development. Although the scheme is still open for approval by the Department for Communities and Local Government (DCLG), the withdrawal of the developer from the scheme casts further and significant doubt on whether the scheme will be realised in the future. It is therefore considered that a CHP connection to the Lodge Hill scheme is currently unviable and therefore not appropriate for further consideration.
Goodman International
Goodman International is currently marketing a large distribution warehouse development immediately to the north and east of the DHC2 site. This scheme is planned to accommodate 185,000 m2 of industrial, distribution and/or warehouse space. The anticipated heating demand of this development was expected to be of medium potential (an annual heat demand of approximately 69kWh/m2/year25 is expected). Note that the nature of some future tenant activities is not known and therefore the heat demand could vary. The developers have been approached and confirmed that their energy strategy will provide for a small onsite CHP plant to serve the Goodman International development directly. It is therefore not considered feasible for the DHC2 site to provide heat to the Goodman International development. It has been confirmed that the CHP plant to be installed at the development is too small to make replacement with DHC2 heat viable.
22 http://www.lodgehill.info/, accessed 31/10/2014 23 CHP-R Assessment, Damhead Creek 2, Parsons Brinckerhoff, June 2009 24 http://www.kentonline.co.uk/medway/news/developer-pulls-out-of-5000-home-43035/ 25 CIBSE Guide F, Table 20.18, Assumed boiler efficiency 75%
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National Grid Site
Outline planning approval has been granted for the National Grid Site development of up to approximately 450,000 m2 of built employment space, which will include business and general industrial uses) with associated infrastructure. The estimated heat consumption associated with this development is approximately 26GWh per year. However, the preferred option for the National Grid Site development is to utilise waste heat from the large scale Grain CHP plant, which is in a closer proximity to the site than DHC2. Therefore, this development is not considered viable for the connection to the DHC2 plant. 2.8.2 CHP Summary The potential schemes identified in consultation with Medway Council are therefore not considered to be viable for connection to DHC2.
Consultation will continue between ScottishPower and local industries and parties in an attempt to identify additional future CHP opportunities as part of the ongoing obligation to periodically reappraise CHP potential opportunities for the Site. Pre-application discussions with DECC National Infrastructure Consents has confirmed that the provision of OCGT capability as part of the development would be acceptable to be considered as a variation to the consent under Section 36C of the Electricity Act 19894. Further detail is included at Section 5.
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3. Legislative Framework
This section briefly reviews the legislative background relevant to the proposed 1,800 MW CCGT with peaking plant scheme option. Prior to the introduction of the Planning Act 200826, Section 36 of the 1989 Act applied to proposals for the construction, extension or operation of an onshore electricity generating station whose capacity exceeds (or, when extended, will exceed) 50 Megawatts (MW). Applications were made to the Secretary of State for Energy and Climate Change, who may give a direction under section 90 of the Town and Country Planning Act 199012 that planning permission be deemed to be granted. Section 20 of the 2013 Act inserted a new section 36C into the 1989 Act. The main aim of section 36C is to make it possible for the design of generating stations, already consented but not constructed, to be modified in ways which the relevant Section 36 consents would not otherwise permit and (in the case of those projects that would otherwise require development consent under the Planning Act 200828) without the developer having to apply for a Development Consent Order (paragraph 15, DECC, 2013). Section 21 of the 2013 Act inserted new sub-sections (2 and 2ZA) into section 90 of the 1990 Town and Country Planning Act12. These amendments make it possible for those schemes which are granted variations to their existing Section 36 consents under section 36C of the 1989 Act to obtain any necessary changes to planning permission from the Secretary of State, or if they choose, to make a separate application to the relevant local planning authority (paragraph 16, DECC, 2013).
As a result of these legislative changes, by applying to vary a Section 36 consent it may be possible to obtain authorisation for a generating station to be constructed, extended and/or operated in a way that would not be consistent with the existing consent (paragraph 2, DECC 2013).
The DECC Guidance indicates there are two broad categories of case in which it is likely that the Secretary of State may consider it appropriate to exercise the power in section 36C. This inter alia includes the construction or extension of a generating station (whose construction or extension has either not yet commenced or has not yet been completed) along different lines from those set out in the existing consent. In addition the DECC Guidance confirms changes in the design of generating stations that have been consented but not constructed, which would allow them to generate an amount of power that would be inconsistent with the original consent, are likely to be appropriate subject matter for a variation application, provided there are no major changes in the environmental impact of the plant.
26 HMSO (2008) ‘The Planning Act’
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4. Status of Pre Commencement Planning Conditions
The Section 90 Direction associated with the Section 36 Consent for DHC2 contained a number of pre- commencement planning conditions. Since the Section 36 Consent was granted in 2011, ScottishPower has been working to discharge these conditions and a summary of progress to date is included in this section. In addition other planning consents have been secured as part of the pre-construction activities and these are set out at Section 4.8. 4.1 Operational Noise Planning conditions 20 and 21 have been discharged (on 21st June 2012 and 15th April 2013 respectively), they related to operational noise. Condition 20 required the production of a NMMP15, the latest version of which (Issue 2 dated January 2013) was approved by Medway Council on 12th April 2013 under reference MC/13/0162. The NMMP set out revised operational noise limits and locations and requires operational noise to be controlled to ensure adequate protection of nearby noise sensitive receptors.
The NMMP15 specifies the following noise monitoring locations:
• Point A – 400 m north of the existing Damhead Creek CCGT Power Station’s air cooled condenser (ACC)27;
• Point B – 400 m east of the existing Damhead Creek CCGT Power Station’s ACC;
• Point D1 – 400m west of the existing Damhead Creek CCGT Power Station’s ACC; and
• Point G - Eschol Lane / Jacobs Lane.
The NMMP15 also contains a programme for the monitoring and control of noise. Condition 21 requires ScottishPower not to exceed the noise limits set out in the NMMP.
Subsequent to the above, it has been agreed with Medway Council that no monitoring at Point B is required, as this location will be within the development footprint for the consented 1,800 MW scheme (it would also be in the development footprint for the proposed CCGT with peaking plant scheme option), and there are no residential receptors in the vicinity of this monitoring location. This is reflected in the proposed amendments to condition 20 and 21 of the Section 90 Direction (see Appendix A).
The NMMP will be reviewed and updated as necessary to ensure the protection of human and ecological receptors from significant noise effects during operation of the proposed 1,800 MW scheme (whichever option is selected for construction). 4.2 Contamination of Watercourses Planning condition 26 relating to the prevention of contamination of watercourses was discharged on the 6th March 2013 under reference MC/13/0061. Conditions 28 to 31 are not pre-commencement conditions. An Addendum to the proposed drainage scheme was submitted to Medway Council for approval in December 2015 (planning reference MC/15/4047) providing additional information in respect of the proposals to prevent the contamination of water courses. At the present time the application to discharge this condition is awaiting determination. 4.3 Ecological Enhancement and Protected Species Schemes for biodiversity enhancement measures and for the protection of water vole habitats were approved under conditions 42 and 43 respectively planning application reference MC/13/2961 on the
27 Description of locations is provided in Damhead Creek Power Station – Application for a Pollution Prevention and Control Permit (PPC Permit), Final Report, March 2006
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12th December 2013 following discussions with Natural England and Medway Council. The approved scheme for biodiversity enhancement measures accords with the approved changes to the former WCA (planning application reference MC/12/2356) and will improve connectivity between mitigation areas, thereby providing a net ecological gain for the area. Key aspects of the biodiversity enhancement scheme are as follows.
• the works have been designed to be sympathetic to mitigation measures proposed for the development of DHC2 and the neighbouring Kingsnorth Business Park;
• a new ecological compensation area has been created to provide the replacement of all habitat types within the WCA at a ratio of no less than 1:1.2, with additional enhancement where possible so as to maximise the quality and connectivity of the habitats throughout the entire ScottishPower landholding;
• the water bodies have been designed to provide optimal habitat conditions for great crested newts and water voles in particular, with the terrestrial habitats designed to provide optimal conditions for great crested newts, reptiles, badgers, invertebrates, breeding birds, foraging and commuting bats and flora;
• a mosaic of waterbodies and terrestrial habitat types have been provided and positioned to provide connectivity to the adjacent and surrounding habitats; and
• the creation of a larger block of continuous habitat further from the operational power stations, which will also provide a ´buffer’ between the development and the Special Protection Area (SPA) to the east of the development site.
Approval was secured from Natural England for licences to translocate water voles and great crested newts (GCN) from the former WCA to new larger areas of mitigation land. GCN trapping in spring/summer 2015 resulted in 997 GCN and 9 water voles being caught and translocated to the new mitigation land. The works, undertaken under licences (Licence EPSA2012-5318 version E, dated 14th April 2015) and (2015-9387-SCI-SCI-1, dated 23rd April 2015) have been completed. 4.4 Ground Contamination Planning conditions 32, 33 and 34 relating to ground contamination were discharged on the 9th January 2013 under reference MC/12/2959. A Ground Investigation and Remediation report was submitted and approved pursuant to planning condition 32. It presented the following results;
• the application site does not pose a risk to controlled waters (Damhead Creek) as only low concentrations of diesel-/oil-range hydrocarbons and chlorinated hydrocarbons were identified in groundwater beneath parts of the site and pulverised fuel ash identified in the centre of the site;
• surface water features on and adjacent to the application site are not significantly affected; and
• identified soil quality and ground gas conditions monitored across the site pose a low risk to the proposed development. On the basis of the above findings the following recommendations were made:
• no remediation is required on the basis of risks to controlled waters or human health; and
• the ground gas regime is such that no remedial measures are required to be incorporated into the proposed development. As a precaution, however, a risk assessment is recommended should vibro piles be considered as part of the foundation design. Planning condition 35 requires ScottishPower to adhere to the recommendation in the report and condition 34 that any contaminated material is to be treated on site in accordance with a scheme to be submitted to and approved by the Council in consultation with the Environment Agency. 4.5 Landscaping and Creative Conservation
A scheme for landscaping and creative conservation was submitted to Medway Council (19th December 2013) and was approved on 4th February 2014 under reference MC/13/3309. Condition 38 has therefore
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been discharged. The scheme includes a Landscape Master Plan which details the landscaping and other landscape features, principally located to the north and north-east of the part of the application site proposed for DHC2. Existing tree planting and earth bunds are present to the north-west of the Damhead Creek CCGT Power Station. The scheme proposes to extend the tree planting and bunds further along the access road to the power station to the north of DHC2. Along the eastern boundary, the security fence will located at the foot of a steep slope which will reduce its visual impact in local views. Much of the proposed planting in the area in the DHC2 site will comprise low scrub and hedgerows as well as small scale ponds. It will therefore be in keeping with the local landscape character and will provide a more natural setting to DHC2.
The approved scheme was designed for the original layout and will be reviewed and updated as necessary to accommodate the proposed 1,800 MW CCGT with peaking plant scheme, when the final layout has been confirmed (whichever option is selected). 4.6 Archaeology ScottishPower are working to discharge conditions 45 and 46 to the satisfaction of Kent County Council Archaeology and Medway Council by arranging for a suitable additional core sample to be taken from the northern area of interest, undertaking the appropriate reporting and updating the historical records sought by the regulators.
Condition 47 was previously reworded, following agreement with Medway Council and the KCCA Officer, to ensure that any potentially significant finds in this area during construction are notified to the Council, and an appropriate course of action is agreed (see Appendix A).
It has also been provisionally agreed informally with Medway Council that no further archaeological investigations are required for the additional DHC2 development area in Area 3 (required for either of the larger proposed 1,800 MW schemes), or for any future CCS development in Areas 2 and 3. These areas have already been subject to an appropriate level of evaluation associated with the Goodman planning permission (ref. MC/08/0370) planning condition discharge ref. MC/12/0875 on 30th April 2012. 4.7 Layout and Design A Design Statement together with a series of drawings consisting of elevational drawings, site layout plans, plant layout drawing and appropriate cros-sectional drawings were prepared and submitted to Medway Council on 16 November 2015, with a revision to the Design Statement and supplementary drawings submitted on 17th December 2015.
The drawings show that the Damhead Creek 2 development is, very broadly comparable in size to the existing Damhead Creek Power Station and similar in appearance, and given the industrial nature of the surroundings, and its close proximity to the original Damhead Creek Power Station, the impact of the proposed siting, design, external appearance and dimensions, including: materials, colour and surface finishes; vehicular circulation roads, parking, hardstandings, turning facilities, etc. will be relatively de- minimus with regard to the wider area.
Overall, given the parallel removal of Kingsnorth Power station, there will be less visual impact on the landscape and seascape. Inevitably the appearance of the power station and the materials used (for mechanical plant, structure and profiled metal cladding) are as a result of the functionality of the development.
It is noted that the higher levels of the site structures, above the 15m AOD plinth, are to be painted a mixture of goose grey and corvette blue. These will be fairly neutral and will help minimise visual impact.
The Design Statement (Revision 1) together with relevant drawings and plans was approved under planning reference MC/15/4047 on 23rd December 2015. 4.8 Green Travel Plan A Green Travel Plan (GTP) was prepared and submitted to Medway Council on 3rd November 2015 to fulfil the requirements of condition 10 of the deemed planning permission. The GTP was prepared having cognisance to both national and local transport policy, and also seeks to build upon the existing ScottishPower operated transport schemes used at various locations throughout the UK.
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This GTP identifies the strategy for supporting DHC2 staff to travel to the site by sustainable travel modes. ScottishPower are committed to the implementation of the GTP once DHC2 is operational. Once DHC2 is operational there will be an opportunity to collect qualitative and quantitative travel information from staff which will be used to update the GTP. The GTP was approved under planning reference MC/15/3907 on 23rd December 2015. 4.9 Construction and Construction Traffic A Construction Environmental Management Plan (CEMP) was prepared and submitted to Medway Council on 3rd November 2015 to fulfil the requirements of condition 11 of the deemed planning permission. The CEMP details the construction and environmental management for the project to ensure all requirements of the relevant CEMP conditions set within the deemed planning permission are understood, communicated and followed at all times during the construction phase of the project. In addition this CEMP supports discharge, or compliance with conditions 6, 12, 13, 14, 15, 16, 17 and 17A of the deemed planning permission.
The CEMP outlines the responsibilities of the key roles during construction to ensure environmental protection requirements and objectives of the project are adhered to, and sets out agreed mitigation measures. The CEMP was approved under planning reference MC/15/4047 on 23rd December 2015.
The Construction Traffic Management Plan (TMP) was prepared and submitted to Medway Council on 3rd November 2015 to fulfil the requirements of conditions 18 and 19 of the Section 90 Direction. The TMP deals with impacts on the local road safety, traffic management and road network condition monitoring during the construction of the main power station area and the delivery of abnormal loads for the project. The document is generally associated with the A289 and A228 (Peninsula Way), Ropers Lane, Stoke Road, Eschol Road and includes the length of the road servicing the access to Damhead Creek Power Station.
The TMP encompasses the construction of all buildings, structures, systems and components of the DHC2 development. It applies to all personnel working at the site, all Contractor employees, Client representatives and any other visitor to this location during the entire construction phase of the project. The TMP was approved under planning reference MC/15/4047 on 23rd December 2015. 4.10 Other Planning Conditions Other planning conditions are required to be discharged prior to commencement of development. The conditions are:
• Condition 5: Wheel washing facilities; and
• Conditions 45 & 46: Archaeology
Documents to discharge these conditions will be completed and submitted prior to the commencement of development. 4.11 Other Planning Consents As discussed in Section 1, ScottishPower secured planning permission from Medway Council on 12th July 2013 (ref. MC/12/2356) allowing the change of use of part of an existing wildlife creation area (WCA).
Planning conditions 3, 4, 5 and 6 attached to this planning permission (water management plan, method statement, habitat suitability surveys and biodiversity monitoring strategy) have been discharged.
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5. Stakeholder Consultation
Regulation 3 of the Electricity Generating Stations (Applications for Variations of Consent) Regulations 20136 states that a variation application must include “3(c)(ii) what account has been taken of views expressed by persons who have been consulted by the applicant about the proposed variation”, Table 5.1.1 below details the consultation that has been undertaken.
Table 5.1.1: Summary of Consultation Regarding Proposed 2016 Section 36 Consent Variation Application
Account Given to Stakeholder Organisation Date Comments from Stakeholder Comments
Medway Council Meeting on 14th Findings of archaeological surveys in Additional borehole sample to be taken and Kent County April 2015 Area 1, combined with the fact that during next Ground Investigation Survey Council construction will not involve deep works, (expected during 2016/17. excavations, are such that limited Previously agreed variation to planning additional survey is required – An Condition 47 included in Appendix A. additional borehole sample is required around the northern part of Area 1 (area labelled BH1). Condition 47 was reworded in 2015 S36 variation to reflect a need to consult and agree and additional surveys with the Council, should any significant finds be made during the construction phase.
Medway Council Email on 6th May Confirmed that the archaeological Agreed. 2015 condition attached to previous Goodman Details of archaeological issues raised by planning permission ref. MC/08/0370 KCC would be responded to. (which covered Areas 2 and 3), was Outlined description of S36C variation discharged under planning ref. and confirmed programme for application. MC/12/0875 on 30 April 2012. As such Also that a PPA between ScottishPower no further archaeological investigations and Medway Council was considered are required in Areas 2 and 3. appropriate means to maintain E-mails of 12th Confirmed S90 conditions relating to programme and that draft PPA would be 20th and 25th archaeology and drainage continue to be provided. January 2015 processed, and that the Route Management Plan obligation contained in S106 agreement should be agreed shortly. Confirmed that terms of PPA appeared reasonable.
Natural England Meeting on 28th Confirmed modelling approach Overview provided of S36 variation April 2015 demonstrating the variable impacts of proposals to outline proposed changes to layout and configuration. capacity outputs and stack heights on the NOx concentrations at the local SSSI site Detailed discussions concerning briefing note on air emissions, and potential Confirmed targets and acknowledged impacts on adjacent SSSI. final stack heights dependent on final capacity and welcomed approach demonstrating worst case outputs E-mail provided by Natural England to this effect.
DECC Meeting on 19th Confirmation that revisions to scheme Overview provided of S36 variation November 2016 would be considered suitable as S36C proposals to outline proposed changes to layout and configuration to allow for variation application OCGT units Confirmation that no space requirement Details provided of programme to meet
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Account Given to Stakeholder Organisation Date Comments from Stakeholder Comments
for CCR for OCGT units as below 300MW 2016 Capacity Auction Confirmation that applicant to consider Details provided of space allocated for CCR and where this is to be provided, external body to validate results of CCR and that no additional space Feasibility Study to accompany requirements necessary for OCGT units application as below 300MW Confirmation that applicant to consider Discussion on procedural requirements the current variation against the approved for S36C Variation application 1800MW scheme from 2015 Requirement for applicant to provide relevant documents to consultees once application accepted for publication Requirement for applicant to prepare revised consultation list and statutory notices
Environment E-mail on 13th Discussion took place on the proposed Overview provided of S36 variation Agency January 2016 introduction of OCGT units as part of the proposals to outline proposed changes to potential layout and configuration. and subsequent development and agreed it would appear telephone there would be no increase in impacts for Discussions confirmed no increased impact from air emissions as a result of conversation on noise, emissions to air and water and th introduction of OCGT units, and potential 18 January CCR impacts on adjacent SSSI. Confirmation 2016 that this would be set out in Air Quality Technical Note and a comparison of previous consented scheme against current proposals would be set out in EIR. Discussions confirmed that existing noise limits would be adhered to. Confirmation that land set aside for 1800MW CCGT would be retained as part of currently proposed scheme, and that in any case the CCR report would be peer reviewed by Imperial College London.
Natural England E-mails on 13th Discussion took place on the proposed Overview provided of S36 variation and 27th January introduction of OCGT units as part of the proposals to outline proposed changes to potential layout and configuration and 1st February development and agreed it would appear 2016 there would be no increase on impacts to Confirmation that environmental information will be updated and Medway Estuary and Marshes SPA and consolidated into an Environmental Ramsar site, such details to be Information Report, and update of the addressed within variation to HRA to confirm no change to impacts to Environmental Permit. Specialist the SSSI/SPA/Ramsar site contacted regarding Air Quality results, discussion progressing under Natural England’s discretionary advice service.
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6. Environmental Appraisal
Using available information, including additional environmental baseline data gathered since the 2009 ES was prepared; the predicted environmental effects of the proposed 1,800 MW CCGT with peaking plant scheme option have been compared to the environmental effects of the currently consented 1,800 MW CCGT-only scheme option. The findings are presented in Sections 6.2 - 6.10 for each of the environmental topics considered in the 2009 ES7, the 2014 EIR8 and the 2015 EIR9, namely:
• air quality;
• noise and vibration;
• landscape and visual amenity;
• ecology;
• water quality;
• geology, hydrology and land contamination;
• traffic and infrastructure;
• cultural heritage; and
• socio-economics. 6.1 Methodology 6.1.1 Environmental Appraisal Baseline information is summarised for each environmental topic using information from the 2009 ES7, the 2014 EIR8, the 2015 EIR9, studies that have been undertaken and reports prepared to discharge the Section 90 Direction planning conditions, and current, freely available sources of information. The baseline information has also been updated, where necessary, to include the current demolition of Kingsnorth Power Station.
The likely effects of the proposed 1,800 MW CCGT with peaking plant scheme option have been identified and assessed by reference to the effects of the currently consented 1,800 MW CCGT-only scheme option. For the purpose of this assessment the same significance criteria have been employed to evaluate and quantify the effects of the proposed 1,800 MW CCGT with peaking plant scheme option as were used in the 2009 ES7 and subsequent EIRs. The assessment is presented in a summary table for each environmental topic in Sections 6.2-6.10 to highlight any differences associated with the proposed 1,800 MW CCGT with peaking plant scheme option when compared to the already consented CCGT-only scheme option. 6.1.2 Consideration of Cumulative Effects This assessment also addresses the potential for the proposed 1,800 MW CCGT with peaking plant scheme option to give rise to cumulative effects. The 2009 ES considered the potential cumulative effects of the proposed construction of two additional units (Units 5 and 6) at Kingsnorth Power Station and the proposed Kingsnorth Business Park. In addition, some topics considered the potential cumulative effects of the (at that time) proposed decommissioning of the existing Kingsnorth Power Station (Units 1-4), where appropriate. Between the date of the 2009 ES7 and the 2014 EIR8, the Kingsnorth Power Station (Units 5 and 6) development proposals were abandoned. It was therefore excluded from the assessment of cumulative effects in the 2014 EIR. This position remains unchanged.
Between the date of the 2014 EIR8 and 2015 EIR9, the decommissioning of the existing Kingsnorth Power Station (Units 1-4) had commenced and was ongoing. It was therefore taken into account in the assessment of cumulative effects in the 2015 EIR.
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Since the publication of the 2015 EIR9, the decommissioning of the existing Kingsnorth Power Station (Units 1-4) has been completed. The programme for demolition is scheduled to continue to 2018, according to information submitted in support of the Prior Notification for Proposed Demolition application submitted to Medway Council. The demolition process has therefore been taken into account in the assessment of cumulative effects. The proposed Kingsnorth Business Park was granted outline planning consent in September 2010. It was, therefore, considered in the 2014 EIR8. Infrastructure works have been completed and construction of some plots within the business park have commenced with others due to commence shortly. One industrial unit has been fully constructed on plot 5 but has not yet been sold or let at time of submission. The situation therefore remains unchanged since the 2014 EIR. The Medway Council planning portal has been checked for any other proposed major developments which may have arisen since the publication of the 2015 EIR9. Several major developments were identified, the majority of which were identified to not have the potential to generate cumulative impacts when considered in conjunction with the development of Damhead Creek 2, given their distance from the Site, their size and their nature. Two developments were identified with the potential to generate cumulative impacts when considered in conjunction with DHC2. These have been assessed in the environmental appraisal, were relevant, and include:
• replacement of the existing structures (B8 use) with the construction of two new buildings (floor area circa 5060 m2) incorporating a 1.8 megawatt biogas combined heat and power plant (sui- generis) and associated storage and car parking (MC/15/4424) - Kingsnorth Industrial Estate, Hoo ST Werburgh, Rochester; and
• construction of a standing reserve power plant comprising 14 gas reciprocating engine generators with an office and storage building, security and acoustic fencing, other ancillary structures and associated works (MC/15/4109) - Land at Kingsnorth Industrial Estate, Gamma Road, ME3 9ND.
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6.2 Air Quality 6.2.1 Introduction This section considers the potential changes to air quality effects on sensitive receptors during construction and operation as a result of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the 1,800 MW CCGT-only scheme option. A Technical Note setting out the Air Quality Assessment that has been undertaken is provided in Appendix D. 6.2.2 Baseline Conditions This section presents a summary of the baseline section presented in the 2009 ES7, and has been updated as appropriate.
Sensitive Receptors The application site is not located within an Air Quality Management Area (AQMA). There are three AQMAs designated for NO2 within 7 km of the application site, located approximately 5 – 7 km to the south and south-west. Given the prevailing wind direction (originating from the south-west), it is considered very unlikely that the emissions from the proposed 1,800 MW CCGT with peaking plant scheme would contribute to exceedances within these AQMAs, which are largely designated due to the impacts of traffic emissions in those areas. Nevertheless, effects on the AQMAs have been considered in the air impact assessment.
The nearest residential receptors to the application site (as reported in the 2009 ES7) are Eshcol Road, located approximately 1 km to the west and Benuncle Farm and White Hall Farm, located approximately 1.1 km to the north-west and north respectively. Additional receptors were identified for the assessment of the now consented 1,800 MW CCGT-only scheme, and these have also been included in this assessment. These include Abbots Court (approximately 1.7 km west), Burnt House Cottage (800 m west), Burnt House Farm (900 m south-west), Sturdee Cottage (1.8 km west) and North Street Farm (approximately 500 m north).
The closest ecological receptor is the Medway Estuary SSSI located to the immediate east of the application site.
Ambient Air Quality The ambient air quality detailed in the 2009 ES was based on monitoring data for the period 2001 – 2005, and is therefore considered to no longer be representative of ambient concentrations of NO2 and NOX in 2015, particularly considering the closure of the Kingsnorth Power Station in 2012. More recent ambient air monitoring data for the period 2009-2013 has therefore been obtained for this assessment.
Medway Council operate a number of urban background automatic air quality monitoring sites in the UK and the results are available from the Council website. The nearest monitoring station to the application site is located at Lower Stoke (referred to as Rochester in the 2009 ES7) (NGR 583100, 176200), approximately 3.9 km north-east of the application site. A second urban background monitoring station is located at Chatham Luton (NGR 577100, 166650), approximately 7.4 km south-west from the application site. These monitoring stations have been in operation for a number of years and may include contributions from the existing Damhead Creek CCGT Power Station. Given the distances from the application site, any effect is likely to have been minor. Results for the years 2009 to 2013 are shown in Table 6.2.1.
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3 Table 6.2.1: Ambient Air Quality Records – NO2 and NOx (µg/m )
Year Lower Stoke Chatham Luton
NO2 Annual NOx Annual NO2 Annual NOx Annual
2009 18 24
2010 25* 24**
2011 19 30
2012 18 24
2013 14 19 24.6 35
Air Quality Standard (AQS) 40 30 40 30
* Data capture only 44% due to cabin replacement therefore not representative of annual concentrations
** Data capture 73% due to technical communication problems following cabin replacement
The ambient concentrations of NO2 and NOX have decreased from those reported in the 2009 ES, as they have across much of the UK over the same period, and it is considered that this is due to year-on- year improvements in NOx emissions from a modernising UK car fleet, and possibly also the closure of the former Kingsnorth Power Station.
7 The 2009 ES included NO2 monitoring data for diffusion tubes within the Medway Council area. As all but two of these monitoring sites are located at road/ kerbside monitoring locations; they are not considered to be likely to be representative of background concentrations in the vicinity of the application site, and therefore have not been updated for this assessment. Two of the diffusion tube monitoring locations are at urban background locations, but they are co-located with the automatic monitoring stations referred to in Table 6.2.1 above, and therefore it is considered more appropriate to use the information from the automatic monitoring sites.
The concentrations of NO2 and NOx for the application site have also been obtained from the Defra background pollutant database, in which pollutant concentrations are averaged over 1 km2 grids across the UK and projected for future compliance purposes. Data for NO2 and NOx is available for 2014 (from 2011 base mapping).
The background concentrations for the criteria pollutants from the Defra database are shown in Table 6.2.2.
28 3 Table 6.2.2: Defra Background Mapping – NO2 and NOx (µg/m )
3 3 Pollutant NO2 (μg/m ) NOx (μg/m )
Defra Background Map 2015 16.2 23.0 (NGR 581500, 172500)
The above demonstrates that NO2 levels in the area are well within the national Air Quality Standard (AQS) objectives13 (see Appendix D). 6.2.3 Differences Between Proposed Scheme Options The following differences between the scheme options being considered are relevant to the air quality assessment (when comparing the already consented CCGT only scheme option and the proposed CCGT with peaking plant scheme option):
28 Department for Food, the Environment and Rural Affairs (DEFRA) (dna(b)) UK-Air website. Available from: uk-air.defra.gov.uk. Accessed 14th April 2014.
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• construction of OCGT unit as peaking plant and one less CCGT unit compared to the 1,800 MW CCGT-only scheme option;
• potential increase in the number of stacks proposed from three to four, albeit two of those stacks will be of a lower height;
• potential stack heights of 50 m have been assessed for the 300 MW OCGT peaking plant; and
• amendments to the likely layout of plant and buildings. 6.2.4 Appraisal of Environmental Impacts and Mitigation Table 6.2.3: Appraisal of Air Quality Effects
1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Construction
An updated Construction Environmental Management Plan All construction works will be carried out in accordance (CEMP) will be submitted to Medway Council for approval before with Conditions 11 and 13, no matter which scheme option the commencement of development. The plan will include how is progressed. As such, the CEMP will be reviewed and dust, airborne pollutants, smoke and odour will be controlled and updated if required and the construction works will be mitigated (Condition 11). undertaken in line with the Section 90 Direction for the No construction work will take place on the site on any Sunday proposed 1,800 MW CCGT with peaking plant scheme or Bank Holiday or on any other day except between 07:00 to option or the already consented 1,800 MW CCGT-only 19:00 on Monday to Friday and 07:00 to 17:00 on Saturday option. (Condition 13). The works will be undertaken in line with the Section 90 direction.
Dust may be generated during several activities associated with No changes to the construction phase impacts on sensitive the construction works, such as earth moving, excavation, receptors are envisaged should the alternative scheme concreting or road construction. option be implemented as dust generation would be Any dust emitted during construction (including land levelling and similar, and best practice mitigation measures (including earth moving operations) would predominantly be of larger damping down and wheel washes) will be implemented diameter (greater than 50 µm) and would tend to resettle on the through the CEMP. ground within 100 to 500 m of the DHC2 site. The 2015 EIR9 identified that dust might affect not only off-site receptors, but also the existing DHC1 (e.g. blocking air filters). The 2009 ES7 identified the nearest identified sensitive residential receptors were located 1 km from the application site and this coupled with the proposed mitigation measures meant that it was considered very unlikely during most weather conditions that dust generated at the DHC2 site would cause a nuisance. The 2015 EIR9 identified additional receptors, the closest of which is North Street Farm (approximately 500 m north). But even at this distance no changes to the construction phase impacts on sensitive receptors were envisaged.
Operation
The plant would be fired exclusively on natural gas and the All environmental controls at the plant and all emissions principal atmospheric emissions during operation would be NOx would comply with the conditions and limits set by the and CO. Environment Agency in the Environmental Permit to All environmental controls at the plant and all emissions would operate DHC2. The proposed emission limits would comply with the conditions and limits set by the Environment remain the same in accordance with the Industrial Agency in the Environmental Permit to operate DHC2. The Emissions Directive18. proposed emission limits would remain the same in accordance with the Industrial Emissions Directive. The worst case annual average impacts of the 1,800 Dry Low NOx (DLN) burners would be used to control the MW CCGT with peaking plant scheme option are slightly
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
emissions of NOx. Therefore the emissions, and resulting effects lower than the 1,800 MW CCGT-only scheme option, on receptors, were not anticipated to be significant. both as a worst case off-site result and at the habitat The 2015 EIR9 noted that the proposed 1,800 MW CCGT-only site. The maximum off-site PEC for the 1,800 MW scheme option would result in an increase in the mass emission CCGT with peaking plant scheme option is 46% compared with 49% for the 1,800 MW CCGT-only rate of NOx, due to the increased air flow through the plant. The stack heights would be determined by reference to the need to scheme option. mitigate the potential for increased impacts on sensitive receptors The worst case hourly average impacts of the 1,800 MW as a result of the increased emissions. In addition, the diameter of CCGT with peaking plant scheme option are slightly the stack would be selected to result in a higher efflux velocity, and higher than the 1,800 MW CCGT-only scheme option, as would lead to better dispersion when compared to the 1,200 MW a worst case off-site result. The maximum off-site PEC scheme. for the 1,800 MW CCGT with peaking plant scheme It was agreed in consultation with Natural England that the stack option is 36% compared with 31% for the 1,800 MW height and emissions conditions will be fixed to ensure continued CCGT-only scheme option. However, the predicted compliance with annual Critical Levels and Critical Loads on the daily mean impacts on the habitat site are comparable Medway Estuary SSSI. for both schemes due to the different dispersal patterns from the three CCGT units to the two CCGTs plus peaking plant. The final stack heights would be determined by reference to the need to mitigate the potential for impacts on sensitive receptors. In addition, the diameter of the stack would be selected to result in a higher efflux velocity, and would lead to better dispersion when compared to the 1,800 MW CCGT-only scheme option. It was agreed in consultation with Natural England that the stack height and emissions conditions will be fixed to ensure continued compliance with annual Critical Levels and Critical Loads on the Medway Estuary SSSI. There would therefore be no additional significant effects arising from the proposed development should the 1,800 MW CCGT with peaking plant scheme option be implemented.
An air quality modelling exercise was reported in the 2009 ES7, An air quality modelling exercise (using the AERMOD based upon the following dispersion model inputs: model) has been undertaken in relation to the proposed 1,800 MW CCGT with peaking plant scheme option, • NOx emission rate: 35.8 g/s; based upon the following dispersion model inputs: • flue gas temperature: 97 °C; • OCGT Hourly NOx emission rate: 15.4 g/s; • flue gas velocity: 25 m/s; and • CCGT Hourly NOx emission rate: 52.4 g/s, • equivalent stack diameter: 5.85 m. • CCGT Annual NOx emission rate: 44.5 g/s The AERMOD model is accepted by the Environment Agency and (Based on 85% annual operation at 100% load); was selected for consistency with previous modelling exercises performed for the existing Damhead Creek CCGT Power Station. • OCGT flue gas temperature: 545.7 °C; In relation to the 1,200 MW scheme (reported in the 2014 EIR8), • CCGT flue gas temperature: 87.8 °C; the following dispersion model inputs were considered: • OCGT flue gas velocity: 37.3 m/s; • NOx emission rate: 35.8 g/s; • CCGT flue gas velocity: 20 m/s • flue gas temperature: 83 °C; • OCGT equivalent internal stack diameter: 5.75 m; • flue gas velocity: 17 m/s; and and • equivalent stack diameter: 8.0 m. • CCGT equivalent internal stack diameter: 8.2 m. The emission scenario differed slightly from that addressed in the Dispersion modelling has been carried out to support 2009 ES assessment due inter alia to a lower flue gas velocity and this variation application, and preliminary modelling has temperature. However, it was not considered likely to have an been carried out to optimise proposed stack heights (see adverse effect on modelling results and therefore no additional Appendix D) based on conservative assumptions. The modelling exercise was undertaken. methodology and assumptions used for the impact assessment have been discussed with and considered It instead proposed that air quality modelling would be undertaken by the EA and Natural England as part of consultation on for the Environmental Permit once a manufacturer has been
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
selected for the plant. the previous 1,800 MW section 36 variation (the In relation to the 1,800 MW (Options 2 and 3) CCGT-only scheme agreements reached apply to this work also). (reported in the 2015 EIR9) option, the following dispersion model Modelling results to date indicate that the predicted inputs were considered: impacts would not prevent the issue of an Environmental Option 2: Permit for the proposed 1,800 MW with peaking plant scheme optionand that the predicted annual levels at the • NO emission rate: 41.6 g/s; x SSSI would not give rise to concern. • flue gas temperature: 77.5 °C; • flue gas velocity: 20 m/s; and • equivalent internal stack diameter: 7.4 m (external diameter up to 11 m). Option 3:
• NOx emission rate: 53.7 g/s; • flue gas temperature: 77.5 °C; • flue gas velocity: 20 m/s; and • equivalent internal stack diameter: 8.4 m (external diameter up to 11 m). Dispersion modelling was carried out as part of the previous 1,800 MW section 36 variation application, and preliminary modelling was carried out to optimise proposed stack heights (see 2015 EIR Appendix C) based on conservative assumptions. The methodology, assumptions and modelling results used were discussed with and considered by the EA and Natural England. The EA, based on the results presented, indicated that the predicted impacts would not prevent the issue of an Environmental Permit. Likewise, Natural England indicated that the predicted annual levels at the SSSI would not give rise to concern.
The stack height modelling, as part of the 2015 EIR9, indicated that The stack height modelling has indicated that stacks of stacks of between 75 m and 95 m were required to mitigate between 75 m and 95 m for the CCGT units, and 50 m potential impacts. The final stack heights would be determined at for the OGCT unit are likely to be required to mitigate the detailed design stage and set to maintain compliance with the potential impacts. The final stack heights will be air quality strategy objectives, annual critical levels and critical determined at the detailed design stage and set to loads at the SSSI. maintain compliance with the air quality strategy objectives and annual critical levels and critical loads at the SSSI.
The results of the dispersion modelling exercise were: The results of dispersion modelling indicate that the • DHC2 will not give rise to high annual ground level impacts of the 1,800 MW CCGT with peaking plant scheme option remain similar to those for the 1,800 MW concentrations of NO2; and CCGT-only scheme option, through modification of the • DHC2 will not significantly increase ground level stack heights and emissions conditions as appropriate. concentrations of NO2 at the various AQMAs in the area. Additional consideration has been given to impacts at The 2015 EIR identified that results of dispersion modelling will the adjacent Medway Estuary and Marshes SSSI, in remain similar through modification of the stack heights and particular the NO critical levels and nitrogen deposition emissions conditions as appropriate. x critical loads. Emissions will not lead to exceedances of Additional consideration was given to the impacts at the adjacent the annual Critical Levels for the Protection of Medway Estuary and Marshes SSSI, in particular the NOx critical Ecosystems. In addition emissions will not lead to levels and nitrogen deposition critical loads. It concluded that nitrogen deposition above the minimum critical load of emissions will not lead to exceedances of the annual Critical habitats identified within the SSSI. Levels for the Protection of Ecosystems and would not lead to nitrogen deposition above the minimum critical load of habitats identified within the SSSI.
Cumulative Effects
The assessment presented in the 2009 ES7 considered the The decommissioning of Kingsnorth Power Station (Units
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potential cumulative effects of DHC2 in conjunction with the 1-4) has been completed, therefore there is no potential for proposed supercritical coal fired power station at Kingsnorth cumulative effects arising as a result of the proposed Units 5 and 6. development and emissions from Kingsnorth Power Cumulative effects during construction were not considered to be Station..The programme for demolition is scheduled to significant. continue to 2018, though no significant air quality effects are anticipated to arise as a result of the demolition once The cumulative impact assessment undertaken in relation to the dust management measures are implemented. original Section 36 application indicated that DCH2, operating in conjunction with the existing Damhead Creek CCGT Power The developments identified with the potential to generate Station and the proposed Kingsnorth Units 5 and 6 would not cumulative effects when considered in conjunction with lead to exceedances of the UK AQS. DHC2 (MC/15/4424 and MC/15/4109 – see Section 6.2) would not cause an exceedance of the hourly NO AQS13 By the time of publication of the 2014 EIR8, the development of 2 and is unlikely to result in an exceedance of the standard Kingsnorth Units 5 and 6 had been shelved and, as a result, no at human health receptors. In addition it is considered that cumulative effects were predicted. the cumulative ecological effects would not be significant. 9 At the time of the 2015 EIR publication, the decommissioning of Therefore, no changes to the potential cumulative effects the existing Kingsnorth Power Station (Units 1-4) had on air quality are envisaged. commenced. However no changes to the potential cumulative effects on air quality were envisaged.
Mitigation Measures
During construction works, good site management practices All measures proposed for the 1,800 MW CCGT-only would help to prevent the generation of airborne dust. To ensure scheme option would be applied no matter which option is that atmospheric dust, contaminants or dust deposits do not progressed. No additional mitigation measures are exceed levels which could constitute a health hazard or considered to be required. nuisance, a dust monitoring programme would be carried out throughout the construction period. An updated CEMP will be submitted to the Council for approval, which would include details of how noise, dust and any other airborne pollutants from construction work would be controlled and mitigated (Condition 11).
During operation, the following mitigation measures have been During operation, the following mitigation measures have included in the design of DHC2: been included in the design of the 1,800 MW with peaking • the use of DLN burners; plant scheme option: • the use of a fuel inherently low in sulphur; and • the use of DLN burners; • a stack of 75 m high. Gas exit velocity and temperature • the use of a fuel inherently low in sulphur; and would be slightly less but sufficient enough to ensure good • a stack of at least 75 m high for the CCGT units and dispersion. 50 m high for the OCGT peaking plant.
6.2.5 Conclusions The results of the dispersion modelling of the operational emissions from the proposed 1,800 MW CCGT with peaking plant scheme option show:
• the worst case annual average impacts of the ‘with peaking plant’ scheme option are slightly lower than the CCGT-only scheme option, both as a worst case off-site result and at the habitat site; and
• the worst case hourly average impacts of the ‘with peaking plant’ scheme option are slightly higher than the CCGT only scheme option, as a worst case off-site result. However, the predicted daily mean impacts on the habitat site are comparable for both schemes due to the different dispersal patterns from the three CCGT units to the two CCGTs plus peaking plant.
As previously agreed with Natural England, the final stack heights on the CCGT and OCGT units will be determined to ensure that emissions from the proposed 1,800 MW CCGT with peaking plant scheme option do not lead to exceedances of the annual Critical Levels for the Protection of Ecosystems, nor exceed the lower end of the critical load range for nitrogen deposition within the SSSI, when in
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combination with background concentrations. As such, the predicted air quality impacts therefore remain consistent with the findings of the currently consented 1,800 MW CCGT-only scheme and within the envelope previously agreed with Natural England for demonstrating that effects on the designated habitat site are not significant.
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6.3 Noise and Vibration 6.3.1 Introduction This section considers the potential changes to noise and vibration effects on sensitive receptors during construction and operation as a result of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the 1,800 MW CCGT-only scheme option. A Noise Assesment undertaken for the proposed development is provided in Appendix F. 6.3.2 Baseline Conditions The noise and vibration assessment presented in Chapter 11 of the 2009 ES7 summarised the baseline conditions. This section presents a summary of that baseline description together with more recent information obtained from the NMMP15 approved by the Council on 12 April 2013 under planning reference MC/13/0162 and work undertaken in relation to the Environmental Permit application (expected to be submitted Q1 2016) for DHC2, and has been updated as appropriate (see Appendix F).
Sensitive Receptors
The application site is located within a predominantly undeveloped area. The site is bounded by agricultural land to the south, by Damhead Creek, a tidal estuary of the River Medway to the east and by the Kingsnorth Industrial Estate to the west. The site of the former Kingsnorth Power Station is located approximately 800 m to the south of the site. There are a number of residential properties in the vicinity of the application site (as reported in the 2009 ES7), which are summarised in 2009 ES Section 5.2.
The NMMP15 specifies noise monitoring locations (Noise Monitoring Points A, B29, D1 and G (see Section 4.1)), which are to be monitored during operation of the DHC2 power station in order to ensure that noise sensitive receptors are given adequate protection.
Noise impact assessment work relating to the Environmental Permit application identified a number of ecological receptors, which include:
• Medway Estuary and Marshes SSSI, SPA and Ramsar (114 m east, 950 m south; and 1.6 km west of the application site);
• Thames Estuary & Marshes SPA (4.7 km north and 9 km east of the application site);
• The Swale SPA and Ramsar (10.1 km east of the application site);
• Queendown Warren SAC (10.5 km south of the application site); and
• North Downs Woodlands SAC (16.5 km southwest of the application site).
Ambient Noise Conditions
The noise and vibration assessment undertaken in support of the original Section 36 application (see 2009 ES7 Volume 2, Appendix F) found that the existing local power generation sources (the existing Damhead Creek CCGT Power Station and, at the now decommissioned Kingsnorth Power Station) were significant contributors to the background noise levels at local noise sensitive receptors. 6.3.3 Proposed Scheme Changes The magnitude of impacts on noise sensitive receptors will depend on the location of proposed noise sources and their noise output. As the detailed design of the proposed DHC2 scheme has not yet been undertaken, assumptions have been made for the purposes of assessment. The noise and vibration assessment takes into account the introduction of new sources of noise with the proposed 1,800 MW CCGT with peaking plant scheme option that could potentially affect the surrounding sensitive environment. The peaking plant is expected to operate a maximum of 1,500 hours per year and it is unlikely that the operation of the gas treatment plant will be required. However, as a worst case
29 Medway Council has subsequently agreed to the removal of Noise Monitoring Point B.
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scenario, it has been assumed that the operation of DHC 2, including that of the peaking plant and gas treatment plant will be continuous throughout the year. 6.3.4 Appraisal of Environmental Impacts and Mitigation Table 6.3.1: Appraisal of Noise and Vibration Effects
1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Construction
Noise Construction is likely to take place over the same period The 1,200 MW scheme identified construction activity will lead to as for the 1,800 MW CCGT-only scheme option, temporary noise disturbance at locations in close proximity to the although one scenario for construction of the peaking construction works. plant after completion of the CCGT units could extend the programme. Potential construction noise impacts were assessed using the methodology set out in British Standard 5228: Construction of the proposed 1,800 MW CCGT with 2009 30(supplemented with the DEFRA Update of Noise Levels for peaking plant scheme option will be in accordance with the Prediction of Noise on Construction and Open Sites31. The the relevant Section 90 Direction conditions, which are: Department for Environment (DoE) Advisory Leaflet 7232 states • Condition 11 – preparation and implementation of a that the noise level outside the nearest occupied room should not Construction Environmental Management Plan exceed 70 dB(A) in rural, suburban and urban areas away from (CEMP) including details of how noise and vibration main road traffic and industrial noise This increases to 75 dB(A) for will be controlled; urban areas near to main roads. • Condition 12 – construction works will be carried out The impact of construction noise was not anticipated to be in accordance with BS 5228:200933 (Part 1 of which significant and the DoE level of 70 dB(A) will not be exceeded at has recently been amended and replaced by BS the closest residential property, located just under 1 km from the 5228-1:2009+A1:201436, which will be followed); construction site. and The 2015 EIR identified that the proposed 1,800 MW CCGT-only • Conditions 13-16 – restrict construction working scheme option may result in more intense periods of activity during hours and impose specific restrictions on impact construction. piling (including seasonal restrictions) and Construction would be in accordance with the relevant Section 90 construction heavy goods vehicle (HGV) Direction conditions, which are: movements. • Condition 11 – preparation and implementation of a Construction noise is not anticipated to be any greater Construction Environmental Management Plan (CEMP) for the CCGT with peaking plant option compared to the including details of how noise and vibration will be controlled; CCGT only option with respect to the nearby Habitats Site. The duration of construction may be longer, but the • Condition 12 – construction works will be carried out in noise levels are not anticipated to vary and therefore no accordance with BS 5228:200933 (Part 1 of which has recently difference in effects is anticipatd. been amended and replaced by BS 5228-1:2009+A1:201433, which will be followed); and In conclusion it is anticipated that the impact of construction noise will not be significant. • Conditions 13-16 – restrict construction working hours and impose specific restrictions on impact piling (including seasonal restrictions) and construction heavy goods vehicle (HGV) movements. The 2015 EIR identified that given the increased intensity of construction works and the requirement to build some of the main plant in Area 3 (closer to the Medway Estuary and Marshes SSSI,
30 British Standards Institution (2009) BS 5228: Code of practice for noise and vibration control on construction and open sites, Part 1: Noise & Part 2: Vibration. 31 Department for Environment Food and Rural Affairs (DEFRA) (2006) Update of noise database for prediction of noise on construction and open sites. 32 Department of the Environment (DOE) (1976) Advisory Leaflet (AL) 72. 33 British Standards Institution (2008) BS 5228-1:2009+A1:2014: Code of practice for noise and vibration control on construction and open sites.
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SPA and Ramsar site), the construction may result in an increase in noise levels at the closest parts of the SSSI/ SPA/ Ramsar site. However, such effects would be temporary and be mitigated and controlled through the agreed restrictions on working hours and construction techniques (including no impact piling from 31st October to 1st March), implemented through the CEMP. The 2015 EIR concluded that the anticipated impact of construction noise would not be significant.
Vibration Vibration Construction activities, such as compacting, breaking or piling, can No changes to the predicted construction vibration be a source of ground-borne vibration. According to British impacts on sensitive receptors are envisaged. Standard 5228 Part 4, vibration problems due to piling could potentially occur within distances of the magnitude of 0-50 m. The nearest residential and sensitive areas are located just over 500m from the construction site. The level of vibration will not be sufficient to reach these receptors.
Operation
Noise levels were calculated using a three dimensional noise The proposed 1,800 MW CCGT with peaking plant propagation model. The model used typical sound power values scheme option will involve the operation of two gas associated with Gas Generation Facilities and calculated the turbines, each with a HRSG and connected to a single spread of noise using the algorithms contained in ISO 9613 Part steam turbine. The peaking plant capacity will be 234). generated through two OCGTs which will be gas fired. The results showed that there will be no significant noise impact Increases in noise may affect residential and ecological during operation. receptors in the vicinity of the site. The 2015 EIR for the 1,800 MW CCGT-only scheme option would Modelling of the proposed 1,800 MW CCGT with involve the operation of up to three gas turbines and associated peaking plant scheme option indicates that predicted equipment, and would increase the number of air cooled noise levels at all sensitive receptors around the site will condensers, with associated noise generation. Increases in noise be below the target noise limits as calculated from the 15 may affect residential and ecological receptors in the vicinity of the NMMP , with appropriate noise control measures in site. place. As part of the application for a variation to the existing Noise levels from the operation of the scheme at Environmental Permit, ScottishPower were required to undertake a habitats sites around the installation (Medway Estuary & noise impact assessment for the operation of the 1,800 MW Marshes) were predicted to be below 55 dB(A), a level CCGT-only scheme option and demonstrate that the installation below which no effect on birds is expected. A small area would operate in accordance with BAT for noise, as outlined in the of the adjacent SSSI is predicted to be subject to up to a Environment Agency’s Horizontal Guidance Note H114. The 10 dB change in noise level as a result of operation of operation of the plant would also be required to adhere to the the CCGT and OCGT units, but this is not considered to absolute noise limits specified in the NMMP15. be significant. On the basis that the 1,800 MW CCGT-only scheme option would On this basis, the proposed 1,800 MW CCGT with operate in accordance with BAT for noise and within the noise peaking plant scheme option is not predicted to result in limits set in the NMMP, the 2015 EIR concluded that the any significant offsite noise impacts. anticipated operational noise effects would not be significant.
Vibration sources during operation will be balanced rotating No changes to the potential operational vibration impacts equipment and wind induced vibrations in the 95m high stacks and on sensitive receptors are envisaged. condenser structures. Since all machinery will be located on considerable foundations and there are no structures whose design will result in undue wind induced vibration, it is not anticipated that the level of induced vibration will be sufficient to propagate to sensitive areas.
34 ISO (1996) ISO 9613-2: Acoustics – Attenuation of sound during propagation outdoors – Part 2: method of calculation.
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Cumulative Effects
The assessment presented in the 2009 ES7 considered the The decommissioning of Kingsnorth Power Station potential cumulative effects of DHC2 in conjunction with the (Units 1-4) has been completed.The programme for proposed supercritical coal fired power station at Kingsnorth Units demolition is scheduled to continue to 2018, however the 5 and 6. overall cumulative noise arising should the construction By the time of publication of the 2014 EIR8, the development of of DHC2 commence prior to the demolition being Kingsnorth Units 5 and 6 had been shelved and, as a result, no completed would not be different for the CCGT with cumulative effects were predicted. peaking plant option compared to the CCGT only option previously assessed. At the time of the 2015 EIR9 publication, the decommissioning of the existing Kingsnorth Power Station (Units 1-4) had commenced. No changes to the potential cumulative effects are However, no changes to the potential cumulative effects on noise envisaged. or vibration were envisaged.
Mitigation Measures
Construction Construction In order to minimise noise impacts from the construction, the Construction of the proposed 1,800 MW CCGT with following mitigation measures were proposed: peaking plant scheme option will be in accordance with • works will be undertaken in accordance with BS 5228- the relevant Section 90 Direction Conditions (11 to 16). 1:2009+A1:201436, which supersedes BS 5228:200933; Works will be undertaken in accordance with BS 5228- 36 • core site working hours to be complied with, asspecified in 1:2009+A1:2014 . Condition 13; Noise limits have been specified at the noise monitoring • specific method and risk assessments would be required for locations that will be adhered to. any night working; The same mitigation measures as proposed for the • effective exhaust silencers will be used; 1,800 MW CCGT-only scheme option will be adopted. • ancillary plant will be positioned so as to cause minimum noise disturbance; and • inherently quiet plant will be used. Noise limits have been specified at the noise monitoring locations that must be adhered to.
Operation Operation Operational noise will be controlled in accordance with the NMMP The proposed 1,800 MW CCGT with peaking plant (Issue 2 dated 6th January 2013)15, which has been approved by scheme option will be operated in accordance with the Medway Council (Condition 20). The NMMP specifies the locations NMMP15. from which noise should be monitored, the measurement method The proposed 1,800 MW CCGT with peaking plant 35 (in accordance with British Standard 4142:1997 ) and the scheme option will also be operated in accordance with maximum permissible levels of noise that should not be exceeded. Conditions 22 – 25. Finally, operational noise will be The noise generated by the normal operation should not exceed controlled and regulated by the EA through the the levels specified in Condition 21 of the Section 90 Direction. Environmental Permit. The NMMP sets the maximum noise levels for the existing Damhead Creek CCGT Power Station (DHC1) and also establishes maximum noise levels for DHC1 and DHC2 combined. At the time the NMMP was submitted and approved, it referred to the 1,098 MW scheme and these details have not yet been updated. The noise limits specified in the NMMP are: • Noise Monitoring Point A (NGR 581000, 173267) 46dB LAeq,TdB - noise Level during operation of DHC1 50dB LAeq,TdB - noise Level during operation of DHC1 & DHC2 • Noise Monitoring Point B (NGR 581416, 172867)
35 British Standards Institution (1997) BS 4142: Method for rating industrial noise affecting mixed residential and industrial areas
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46dB LAeq,TdB - noise Level during operation of DHC1 55dB LAeq,TdB - noise Level during operation of DHC1 & DHC2 • Noise Monitoring Point D1 (NGR 580670, 172885) 46dB LAeq,TdB - noise Level during operation of DHC1 50dB LAeq,TdB - noise Level during operation of DHC1 & DHC2 • Noise Monitoring Point G (NGR 172534, 172534) 37dB LAeq,TdB - noise Level during operation of DHC1 40dB LAeq,TdB - noise Level during operation of DHC1 & DHC2 The 2015 EIR identified that Medway Council agreed that monitoring at Noise Monitoring Point B was not required due to the extended footprint of the 1,800 MW CCGT-only scheme option and absence of human receptors in the area. A variation to condition 20 was made as part of the Section 36 Variation consent. Since the approval of the NMMP, British Standard 4142 199738 was replaced and superseded by BS4142:2014 ‘Methods for Rating and Assessing Industrial and Commercial Sound’36. The 2015 EIR stated that the NMMP would be updated to the new British Standard and the 1,800 MW CCGT-only scheme option would be operated in accordance with the revised NMMP. The 1,800 MW CCGT-only scheme option would be operated in accordance with Conditions 22 – 25, relating to the preparation of an acoustic assessment of compliance, emergency exceedances of noise levels, operation of emergency pressure relief valves or similar equipment, and a noise complaints procedure. Finally, operational noise would be controlled and regulated by the EA through the Environmental Permit.
In addition to the measures included in the NMMP, the following No changes to the proposed operational phase mitigation measures were proposed: mitigation are considered to be required. • plant items will be silenced or controlled; • inherently quiet plant items will be selected; • acoustic enclosures will be considered for all plant items; and • internal surfaces within the turbine hall will be treated to avoid reverberant noise levels.
6.3.5 Conclusions The assessment of noise and vibration effects has included consideration of residential and ecological receptors, including Medway Estuary and Marshes SSSI, SPA and Ramsar site. The results of the noise modelling indicate that predicted noise levels at all noise sensitive receptors around the site will not result in any significant offsite noise impacts with the proposed 1,800 MW CCGT with peaking plant scheme option. Mitigation measures will include restrictions on construction working hours, daily as well as seasonal restrictions on impact piling, the implementation of BAT for control of noise during the design and operation of the scheme, measures to reduce noise at source, compliance with absolute noise limits, and noise monitoring in accordance with the previously agreed NNMP to demonstrate adherence to the agreed noise limits at defined monitoring locations.
36 British Standards Institution (2014) BS 4142: Methods for rating and assessing industrial and commercial sound.
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6.4 Landscape and Visual Amenity 6.4.1 Introduction This section considers the potential changes to effects on landscape and visual amenity during construction and operation as a result of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the 1,800 MW CCGT-only scheme option. The assessment has been undertaken by Optimised Environments Ltd. The differences in dimensions of the two proposals are set out in Table 2.4.1 in Section 2.4. Figure 2 illustrates the scale and massing of the main components of the DHC2 proposal. 6.4.2 Baseline Conditions The landscape and visual assessment presented in Chapter 12 of the 2009 ES7 summarised the baseline conditions, in terms of landscape character and potential visual receptors and was updated in the 2014 EIR8 and 2015 EIR9. The baseline used in the original assessment and for the 1800 MW Variation (presented below) is in the process of change with the demolition of Kingsnorth coal fired power station. Kingsnorth Power Station is a noticeable feature in views and it adds substantially to a context of large industrial buildings and a degree of screening in some viewpoints. Its relationship to Damhead Creek 1 CCGT (DHC1) and the proposed 1800 MW Variation (DHC 2) sites is illustrated in Figure 1 of Appendix G. Although the 1800 MW CCGT only scheme option was consented with the knowledge that the Kingsnorth Power Station was to be demolished, the demolition has now started and any screening provided by the power station is likely to be short to medium term. The change in context resulting from the demolition of Kingsnorth power station therefore applies to whichever scheme is implemented for DHC2.
Landscape Character The application site is located on the southern edge of the Hoo Peninsula overlooking the Medway Estuary. The existing Damhead Creek CCGT Power Station site is located to the north of the site of the former Kingsnorth Power Station.
The application site currently comprises areas of unmanaged grassland, scrub and hardstanding. The application site is underlain by London Clay covered by superficial alluvium deposits. The land is thought to have been drained in the late 19th Century for agricultural purposes. The other main use of the land has been as a naval airship installation between 1912 and 1920.
The land within and immediately surrounding the application site is fairly flat and low lying at an average of approximately 3.2 m AOD. To the north and west the land rises gently to around 50 m AOD on the wider Hoo Peninsula.
The landscape of the Medway Marshes to the south and east of the application site is typical of the Medway Estuary. The land is flat with a mix of narrow creeks, saltings, mudflats and small islands. Damhead Creek is the main nearby inlet, which drains into the Medway Estuary. The high tide mark is defined by the raised bund of the sea wall. The larger conurbations of Chatham and Gillingham are located on the southern side of the Medway Estuary.
The land immediately north, west and south of the application site is industrial in use and character. Land to the west comprises the existing Damhead Creek CCGT Power Station. To the south, there is a strip of undeveloped land, which separates Damhead Creek from the site of the former Kingsnorth Power Station. The existing Kingsnorth Industrial Estate is located to the north and east.
Within these industrial areas there are belts of tree and shrub planting, the more substantial and mature areas are associated with the former Kingsnorth Power Station. A belt of hybrid poplars follows the southern boundary of the Kingsnorth Industrial Estate and there are a number of young tree and shrub belts associated with the existing Damhead Creek CCGT Power Station site.
The site of the former Kingsnorth Power Station, which lies approximately 500 m south of the application site, is the largest existing development in the locality in terms of land take, the scale of the main buildings and plant and the height of the stack at 198 m. Kingsnorth Units 1-4 are closed and demolition commenced in March 2014 and is expected to be finished by 2018 according to information submitted in support of the Prior Notification for Proposed Demolition application submitted to Medway Council.
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To the north and west, the land rises gently to the undulating agricultural landscape of the Hoo Peninsula. The majority of the land is under mixed arable and vegetable production. Fields are, in the main, large in size and bordered by a combination of fragmented hedges, ditches and shallow bunds. There is limited woodland cover, although hedge lines (including some domestic conifer hedges) and occasional hedgerow trees do break up the open character of the landscape. The landscape is traversed by pylons emanating from the electricity substation at the former Kingsnorth Power Station site. There is a network of narrow country lanes and a number of public rights of way (PRoW) (mostly footpaths) including sections of the Saxon Shorne Way Long Distance Footpath.
The main settlements in the immediate locality are Hoo St Werburgh, to the west, and Stoke to the north-east. Hoo St Werburgh is the largest local settlement and comprises a small, old centre surrounded by extensive post war residential development. There are also areas of linear development on the A228 around Sharnall Street and Fenn Street and a number of smaller groups of properties around Tunbridge Hill and North Street. There is no strong settlement pattern or architectural style that would characterise these local towns and villages.
The Medway Landscape Character Assessment37 subdivides the landscape into differentiated areas. The areas including the former Kingsnorth Power Station site, the existing Damhead Creek CCGT Power Station, the proposed DHC2 site, and adjacent land surrounding these developments are identified as urban/ industrial areas. Beyond this immediate area, the landscape is classified as either the Hoo Flats or Lower Stoke Farmland and the assessment recognises that there is an existing influence from the power stations on the character of these landscapes.
Potential Visual Receptors A predicted zone of visual influence (ZVI) was assessed as part of the 2009 landscape and visual assessment in the 2009 ES7 to identify sensitive landscape and visual receptors and to assess the overall character, quality and condition of the local landscape. The ZVI has been updated to account for the now demolished Kingsnorth Power Station and the updated findings are summarised in this section.
Views from the North
The land rises gently to the north towards a broad ridge which runs from St Mary Hoo, south-eastwards to High Halstow and rising still further towards Lodge Hill. The landscape is typically open and undulating comprising agricultural land with occasional small settlements (Tunbridge Hill and North Street) and individual farms and properties. There is a network of narrow country lanes and public rights of way (PRoW). Expansive views can be gained from many locations towards the Medway Estuary to the south and east. The existing Damhead Creek CCGT Power Station is a dominant feature in these views as was the now demolished Kingsnorth Power Station.
The A228 runs just below the crest of the ridge between Chattenden and Lower Stoke. Vehicle travellers on the A228 gain middle distance views over the rolling farmland towards the application site. In addition there are a number of small, mainly linear settlements on the A228 (Sharnal Street and Fenn Street) and other individual properties, which benefit from similar views.
Views from the West
Hoo St Werburgh, the largest settlement in the immediate vicinity of the application site is located just over 3 km to the west. The older centre of the town is located on the edge of the Medway marshes. Built development has more recently expanded to the higher land to the north and west of the town. Properties on the eastern edges of the town benefit from views to the south and east towards the application site.
The intervening flat areas of arable farmland and grazing marsh are traversed by a network of ProW, which includes the Saxon Shorne Way. There are a number of clumps of riparian woodland and scrub, which serve to break up views towards the application site.
37 Medway Council (2011) Medway Landscape Character Assessment
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South-west of Hoo St Werburgh the land rises in the form of a shallow ridge towards Beacon Hill and Broad Street. The Saxon Shorne Way follows the crest of the ridge, with views south and east over the Medway Estuary and towards the application site.
Views from the South
There are expansive open views northwards over the Medway Estuary towards the application site from the Estuary itself and areas on the southern side of the Estuary. To the south-west, much of the land bordering the Estuary is residential and industrial in character and includes the new residential development on St Mary’s Island, the Strand Riverside Park Leisure Centre and other development on the northern edges of Chatham and Gillingham along the A289. East of Gillingham, the land is more rural in character, but includes popular recreation destinations such as Riverside Country Park. The Saxon Shorne Way follows the estuary edge through much of this area. There are expansive views over the Medway Estuary towards the Hoo Peninsula and the Isle of Grain.
Views from the East
Land to the east is predominantly flat and extends to the nearby industrial developments on the Isle of Grain. The intervening land combines estuary and grazing marsh. Long and middle distance views can be gained over this flat landscape, in particular from the footpath, which follows the crest of the flood defence bund.
Stoke, Middle Stoke and Lower Stoke are all small settlements located on the slightly higher ground to the north-east. Stoke is the closest of the three settlements and properties on the southern and western edges of the village benefit from expansive views over the Medway Estuary to the south-west.
Viewpoints
The 2009 landscape and visual assessment identified eight viewpoints to provide a representative illustration of the potential visual effects, and these were also used for the assessment of the 1,200 MW scheme in the 2014 EIR and 2015 EIR, following agreement with Medway Council. A level of sensitivity to change was assigned to each. The viewpoints and their sensitivity were as follows:
• St. Mary’s Island, viewing point from Finsborough Down (Moderate);
• View from causeway at Horrid Island in Riverside Country Park (Moderate);
• Raspberry Hill, looking across Bedlam’s Bottom (Moderate/ Low);
• View from the junction between Vicarage Lane and Abbots Court Road on the southern edge of Hoo St Werburgh (High);
• Junction between A228 (Fenn Street) and Ratcliffe Highway at Fenn Street, east of High Halstow (Moderate);
• Footpath RS33 (on flood defences) adjacent to A228, just south of Stoke Marshes (Moderate);
• Stoke Road at the junction with Creek Lane on the southern edge of Stoke village (High); and
• Tunbridge Hill on Stoke Road (High). As noted above, the former Kingsnorth Power Station was a noticeable feature in views, adding substantially to a context of large industrial buildings and a degree of screening in some viewpoints. Demolition of this site has now started and any screening provided by the power station is likely to be short to medium term. With this in mind a supplementary assessment has been added to this Variation application which takes into account the removal of the Kingsnorth Power Station. The proposed 1,800 MW CCGT with peaking plant scheme option is then compared with the revised assessment, with the assumption that the Kingsnorth Power Station will be demolished at the time of construction and operation of either scheme. Figures have been prepared showing the proposed 1,800 MW CCGT with peaking plant scheme option without Kingsnorth Power Station (see Appendix G). The sensitivity ratings of the receptors being assessed however remains unchanged.
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The revised assessment, focuses on the extent to which the magnitude of change has altered as a consequence of the changes in the layout and arrangement of the components of the proposed 1,800MW CCGT with peaking plant scheme option as well as how the scale, form and massing have changed the overall appearance when compared with those of the consented 1800 MW CCGT. Model views from each viewpoint illustrate the differences. The findings show that while differences in appearance may be apparent for some receptors, essentially the effect on landscape character and visual amenity remains broadly unchanged. The proposed development in both cases appears as a power station of similar scale and mass, seen within a context in which the existing power station forms an integral part of the baseline situation. The clustering of such developments means that the proposed 1,800 MW CCGT with peaking plant scheme appears as a logical extension associated with the existing DHC1 Power Station. In comparison with the current baseline view, which contains the Kingsnorth Power Station the proposed development appears less prominent. The removal of the Kingsnorth Power Station is likely to take some time (2018) and therefore there may be a gradual transition between the different developments within this area being removed/becoming visible. The visualisations which accompany the revised LVIA are included at Appendix G. 6.4.3 Proposed Scheme Changes The following were taken into account as changes in the proposed 1,800 MW CCGT with peaking plant scheme option:
• Number of stacks will decrease from three to two for CCGT units; the heights of these stacks will remain within a range of 75 m to approximately 95 m (illustrated in the photomontages at Appendix G at 95 m height);
• Peaking plant introduces two smaller stacks with potential stack heights of 50 m; and
• arrangement of the components and their specific dimensions; air cooled condensers have been relocated and the Peaking Plant is sited on this area to the north-east of the drainage ditch. 6.4.4 Appraisal of Environmental Impacts and Mitigation Table 6.4.1: Appraisal of Landscape and Visual Effects
1,800 CCGT-only MW Scheme Proposed 1,800 MW CCGT with peaking plant Scheme option
Construction
The following elements of the construction process were identified as Although the proposed 1,800 MW CCGT with peaking having the potential to impact on landscape character and visual plant scheme option components and their layout have amenity: changed, the construction process remains largely the • temporary site compounds, including lighting, fencing and same. The following elements of the construction temporary buildings and structures; process are identified as having the potential to impact on landscape character and visual amenity: • lay-down areas for the storage of materials and other plant/ machinery; • Temporary site compounds, including lighting, fencing and temporary buildings and structures; • site clearance including land associated with application site and other temporary site compounds; and • Lay-down areas for the storage of materials and other plant / machinery; • temporary plant such as cranes and vehicle movements associated with construction on the application site. • Site clearance including land associated with the proposed 1,800MW CCGT with peaking plant In order to deal with the potential impacts of construction, two scheme site and other temporary site compounds; documents were proposed; and • a Construction Environmental Management Plan (CEMP); and • Temporary plant such as cranes and vehicle • a restoration plan. movements associated with construction on the The CEMP will address issues such as temporary storage of topsoil, proposed 1,800 MW CCGT with peaking plant temporary protection of vegetation and other features, design and scheme site. layout of site construction areas and agreed site access routes and The impacts of construction will be addressed through measures for the protection of vegetation, verges and other
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landscape features, as well as reinstatement where necessary. an updated construction environment management In accordance with Section 90 Direction conditions 38 to 41, a plan (CEMP) and a restoration plan. The Report Landscape and Habitat Management Plan (restoration plan), which entitled Planning Conditions Discharge Summary: included a Landscape Masterplan, was approved in 2014. The Plan Landscape and Creative Conservation (Conditions 38 provides greater detail as to the proposed landscape works as well - 41) Issue 1.0 - Final", dated 16 December 2013 and as the longer term management of the landscaped areas around the approved by the Council on 4 February 2014 pursuant plant. The 2015 EIR identified that the approved Landscape and to planning reference MC/13/3309, provides greater Habitat Management Plan (restoration plan)16 would be reviewed detail as to the proposed landscape works as well as and updated, as necessary. the longer term management of the landscape area around the plant. The conclusion in terms of the assessment of residual effects as a result of the construction phase was that effects would be neutral The overall effect of the construction of DHC2 will be and not significant, since all temporary construction areas would be neutral and not significant. re-instated in accordance with the CEMP and Landscape and Habitat Management Plan.
Operation
Approximately 10.4 ha of land (including some former mitigation land The plant will be largely located within the same area known as the wildlife creation area (WCA)), to the east of the as the 1800 MW CCGT-only scheme option. The area existing Damhead Creek CCGT Power Station will be available to not used for the development will remain the development of the main plant. approximately the same. The area affected is shown at The main plant will comprise up to three gas turbines, with Figures 4a and 4b. associated HRSGs serving steam turbine equipment. The turbines The principal differences between the 1800MW will be located within Area 1 and part of Area 3, with three stacks of CCGT-only scheme option and the proposed 1,800 height up to 95 m (the highest components of the plant). MW CCGT with peaking plant scheme option include The buildings and plant will be of a modern and functional design the arrangement of the components and their specific and will be industrial in character and appearance. They will relate dimensions (Figure 5). The air cooled condensers for closely to the existing Damhead Creek CCGT Power Station in terms Option 3 of the 1800 MW CCGT have been relocated of scale, design, appearance and colour. The structure will have a and the Peaking Plant is sited on this area to the relatively simple clear outline, with the use of cladding and materials north-east of the drainage ditch. The number of CCGT with finishes in recessive colours, to match the existing Damhead stacks may decrease from three to two under the Creek CCGT Power Station. CCGT with peaking plant scheme option, however the peaking plant will introduce two smaller stacks. The The main impacts associated with the operation of DHC2 were final number and height of stacks will be determined at anticipated to be: detailed design, depending on the development option • permanent daytime visual impacts which will introduce new, selected for implementation. industrial plant to the locality; The effects of the proposed 1,800 MW CCGT with • permanent night time visual impacts associated with lighting; peaking plant scheme option are assessed in the • new perimeter fencing and internal access roads; following sections. • change of land use from the current undeveloped use; and • loss of existing landscape features. The approved Landscape and Habitat Management Plan (restoration plan)16 includes the Landscape Masterplan as well as the longer term management of the landscape area around the plant. The 2015 EIR9 identified that the approved Landscape and Habitat Management Plan would be reviewed and updated, as necessary.
Landscape Assessment Landscape Assessment Effects on the following components of the landscape were ‘Medway Landscape Character Assessment’ provides assessed: a detailed classification of the Medway landscape. It • landscape pattern; subdivides the landscape into more closely differentiated areas than the original assessment. The • tranquillity; remoteness and sense of isolation; most significant change brought about by the • cultural and historical associations/ features and their settings; document is that the areas including Kingsnorth Power and Station, existing DHC1 Power Station, the proposed • land cover, land use, ecology and management. DHC2 site, and adjacent land surrounding these developments, are identified as urban / industrial
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The area including Kingsnorth Power Station, existing Damhead areas. Beyond this area, the landscape is classified as Creek CCGT Power Station, the proposed DHC2 site, and adjacent either the Hoo Flats or Lower Stoke Farmland. The land surrounding these developments is classified as urban/ assessment recognises that there is an existing industrial areas in the Medway Landscape Character Assessment. influence from the power stations on the character of As such, the DHC2 site would be contained in an area already these landscapes. identified as having an urban/industrial character. The effect of introducing DHC2 into this urban / The landscape assessment concluded that the effects on local industrial area was found in the previous assessments landscape character would be slight adverse and therefore not as slight adverse and not significant. significant. The proposed 1,800 MW CCGT with peaking plant scheme option is located generally within the same part of the site and is broadly similar in terms of appearance to the 1,800 MW CCGT-only scheme option. The effects of this development on the components of the landscape, as well as the character of the surrounding landscapes will therefore be similar and overall, were found to be slight adverse and not significant. The classification in the Medway Landscape Character Assessment of the area including Kingsnorth Power Station, existing DHC1 Power Station, the proposed DHC2 site, and adjacent land surrounding these developments as urban / industrial areas means that DHC2 will be contained in an area already identified as having an urban / industrial character.
Visual Assessment Visual Assessment The visual assessment was based on eight viewpoints selected to The visual assessment is based on eight viewpoints represent the visual amenity of the area around the application site. (Appendix G Figures 3-10) selected to represent the The viewpoints represent the principal receptors of roads, footpaths visual amenity of the area around DHC2. The and settlements in the vicinity. Revised photomontages for each viewpoints represent the principal receptors of roads, viewpoint for the 1,800 MW CCGT-only scheme option was provided footpaths and settlements in the vicinity of the site. in the 2015 EIR9 (Appendix E). The visual assessment presents a comparison between the potential impacts of the previous 1,800 MW CCGT-only proposal and the current proposed 1,800 MW CCGT with peaking plant scheme option. It highlights where there is variation in the predicted effects and the conclusions as to whether or not these effects will be significant..
Viewpoint 1 – St. Mary’s Island Viewpoint 1 – St. Mary’s Island (Assessment with Kingsnorth Power Station removed). • DHC2 still screened by woodland along Saxon’s Shore Way, although the outline of one stack is just visible. May be visible The photomontage shows the proposed 1,800 MW from further east along the coast, but limited magnitude of CCGT with peaking plant scheme option also change due to scale comparison with woodland and existing screened by woodland planting. While the outline of influence of power stations on views. one stack is just visible through the bare trees, the • Sensitivity of visual receptor – high. visual influence on this view will be very limited. Further east along the coast, where the proposed • Visual impact – neutral to slight adverse (not significant). 1,800 MW CCGT with peaking plant scheme option Assessment with Kingsnorth Power Station removed: may be visible to the right of the woodland cover, the The removal of the Kingsnorth Power Station will reduce the scale comparison between the closer range trees and presence of large scale power plants in the view although the stack the more distant proposed 1,800 MW CCGT with of the existing Damhead Power Station is still visible alongside peaking plant scheme option will reduce the perceived several pylons. The 1,800 MW CCGT-only scheme option is not scale of the stacks. screened by the Kingsnorth Power Station in this view but will remain The visual impact of the proposed 1,800 MW CCGT screened by woodland planting. While the outline of one stack is just with peaking plant scheme option will remain neutral visible through the bare trees, the visual influence on this view will be and the effect on views from St. Mary’s Island will very limited. Further east along the coast, where DHC2 may be remain not significant. Further east along the coast
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visible to the right of the woodland cover, the scale comparison where DHC2 may be seen in part, the visual impact between the closer range trees and the more distant DHC2 will will be slight adverse and the effect will remain not reduce the perceived scale of the stacks. The addition of DHC2 to significant. views to the east will have a limited magnitude of change, on account of the scale comparison with the woodland and the existing influence of the existing power station in these views. The visual impact of DHC 2 will be neutral and the effect on views from St. Mary’s Island will remain not significant. Further east along the coast where DHC2 may be seen in part, the visual impact will be slight adverse and the effect will remain not significant.
Viewpoint 2 – Horrid Island, Riverside Country Park Viewpoint 2 – Horrid Island, Riverside Country Park (Assessment with Kingsnorth Power Station removed) • DHC2 largely screened by Kingsnorth Power Station – only two stacks visible, and their scale appears modest in comparison to The model views and photomontage shows the the Kingsnorth stack. proposed 1,800 MW CCGT with peaking plant scheme • Sensitivity of visual receptor – high. option is very similar in size and scale to the 1800MW Variation DHC2, but has one less main stack and • Visual impact – neutral to slight adverse (not significant). lesser apparent horizontal spread. The proposed Assessment with Kingsnorth Power Station removed: 1,800 MW CCGT with peaking plant scheme option The removal of the Kingsnorth Power Station reveals the full extent therefore slightly reduces the built elements in the of the Damhead Creek CCGT Power Station (DCH1). The stacks of view, but will be visible in conjunction with DHC1 and DHC 1 are similar in height to the surrounding pylons, but the stacks from this distance will appear to extend the horizontal in combination with the massing of the existing of the buildings expanse of the existing building mass to a similar but maintain industrial forms as a key characteristic and focus in the slightly lesser extent than the 1800MW Variation due view. The addition of the 1800MW Variation DHC2 increases the to the relocation of the larger form of air cooled number of stacks and the horizontal extent of the buildings which condensers. increases the mass of this focal feature - although it appears at a The visual impact will be slight adverse and the effect smaller scale than the Kingsnorth Power Station. will remain not significant. The 1800MW Variation DHC2 appears at a similar scale to the existing Damhead Creek CCGT Power Station, but with slightly taller stacks. The 95m stacks repeat the vertical elements of the existing Damhead Creek CCGT Power Station. The visual impact will be slight adverse and the effect will remain not significant
Viewpoint 3 – Raspberry Hill Lane Viewpoint 3 – Raspberry Hill Lane (Assessment with • DHC2 located to the right of DHC1. Stacks slightly more Kingsnorth Power Station removed) prominent due to increase from 75 to 95 m and two to three The photomontage shows the proposed 1,800 MW stacks, and the 1,800 MW CCGT-only scheme option increases CCGT with peaking plant scheme option is very similar extent of development on site further to the east. Impact in size and scale to the 1,800MW Variation DHC2, but moderated by distance from viewpoint (approx. 8.8 km). has one less main stack. Further, shorter stacks are • Sensitivity of visual receptor – moderate. apparent to the right of the main stacks, marking the visible extent of the proposed 1,800 MW CCGT with • Visual impact – neutral to slight adverse (not significant). peaking plant scheme option. The proposed 1,800 MW Assessment with Kingsnorth Power Station removed: CCGT with peaking plant scheme option slightly Kingsnorth Power Station is the primary focal point in this part of the reduces the built elements in the view, but will be view, with DCH1 appearing as a secondary focal point. The removal visible in conjunction with DCH1 and will appear to of the Kingsnorth Power Station will make DHC1 the main focal point extend the horizontal expanse of the existing building in this part of the view. mass to a similar extent to the 1800MW Variation The 1800MW Variation is situated to the right of the existing DHC1 DHC2. The impact of these changes will be moderated Power Station, and appears to the fore of the DHC1 buildings. The by the distance of approximately 8.8km at which they slightly taller stacks reinforce the apparent closer proximity in the will be seen as a minor part of an extensive wider perspective and therefore do not appear incongruous. The main horizontal expanse. buildings appear at a similar scale to the existing Damhead Creek The visual impact will be slight adverse and the effect CCGT, although the air cooled condensers appear as a separate, will remain not significant. larger element. The impact of these changes will be moderated by the distance of approximately 8.8km at which they will be seen and
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which means they will appear incremental in scale. The visual impact will be slight adverse and the effect will be not significant.
Viewpoint 4 - Vicarage Lane, Hoo St. Werburgh Viewpoint 4 - Vicarage Lane, Hoo St. Werburgh • 1,800 MW CCGT-only scheme option partially screened by (Assessment with Kingsnorth Power Station removed) intervening tree cover; tops of three stacks visible above tree The proposed 1,800 MW CCGT with peaking plant tops. Stacks viewed between and slightly below existing stacks scheme option is in a similar location to the 1800MW and pylons. Increased stack height is apparent. Variation and is therefore also partially screened by • Sensitivity of visual receptor - moderate. intervening tree cover. The visible components are the two stacks which are similarly contained between the • Visual impact – slight adverse (not significant). stacks of the existing DHC1 CCGT Power Station and Assessment with Kingsnorth Power Station removed: the pylons, thus preventing any horizontal spread of The removal of the Kingsnorth Power Station, removes a focal point development. The stacks will appear at a similar in the view. The shorter stacks of the existing DHC1 merge with height to the pylons. pylons and the main buildings appear behind intervening hedgerows The differences between the 1,800 MW CCGT with and vegetation such that they are less prominent than Kingsnorth as peaking plant scheme option and the 1800MW a focal point in views from this edge of the village. Variation will not form a notable change and therefore In the photomontage, the 1800MW Variation is partially screened by the visual impact will remain slight adverse and the intervening tree cover. The visible components are the three stacks effect will be not significant. which are contained between the stacks of the existing DHC1 CCGT Power Station and the pylons, thus preventing an increased horizontal spread of development. The stacks are apparent alongside the existing stacks of DHC1 and pylons where they form a cluster of vertical elements. The visual impact will be slight adverse and the effect will be not significant.
Viewpoint 5 – Junction between A228 and Ratcliffe Highway Viewpoint 5 – Junction between A228 and Ratcliffe • 1,800 MW CCGT-only scheme option increases horizontal Highway (Assessment with Kingsnorth Power Station extent of development further to the left of Kingsnorth Power removed) Station and three 95 m stacks more prominent than two 75 m The proposed 1,800 MW CCGT with peaking plant stacks. scheme option is in a similar location to the 1,800MW • Sensitivity of visual receptor - moderate. Variation DHC2, albeit with one less main stack. The two main stacks repeat the existing pair of stacks at • Visual impact – slight to moderate adverse (not significant). DHC1 and appear less prominent in the view than the Assessment with Kingsnorth Power Station removed: 1,800MW CCGT-only Variation. Two smaller stacks at The removal of the Kingsnorth Power Station, removes a focal point the peaking plant, again repeat the pattern, but do not in the view. The shorter stacks of the existing DHC1 are less appear above the skyline. All of the other built prominent above the skyline in comparison with Kingsnorth and are elements are either screened by intervening landform less noticeable as a focal point in the view. The lower elevation of or are similarly beneath the skyline in the view which 1800MW Variation relative to the viewpoint means that the lower moderates their impact. parts of the development are screened by intervening landform, and The vertical stacks above the skyline merge with other as such, only the upper parts of the stacks and the larger buildings vertical elements such as signage and lighting are visible. The 1,800MW Variation increases the horizontal extents columns and form a minor part of the view at this of development to the left of the existing Damhead Creek CCGT location. Power Station. The three 95m stacks are slightly taller than the The introduction of the 1,800 MW CCGT with peaking existing Damhead Creek CCGT Power Station stacks. While the air plant scheme option will not form a notable change in cooled condenser building appears offset to the left, its containment impact from the 1,800MW Variation and therefore the below the skyline moderates its impact. visual impact will remain slight adverse and the effect The visual impact will be slight adverse and the effect will be not will remain not significant. significant.
Viewpoint 6 – Footpath RS33, Stoke Marshes, A228 Viewpoint 6 – Footpath RS33, Stoke Marshes, A228 • DCH2 located between existing Kingsnorth and Damhead Creek (Assessment with Kingsnorth Power Station removed) Power Stations so does not increase horizontal extent of The proposed 1,800 MW CCGT with peaking plant
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development. 1,800 MW CCGT-only scheme option slightly scheme is also located to the fore and immediate left more prominent due to taller stacks but impact moderated by of DHC1. The two main stacks repeat the pattern of distance (approx. 4.3 km). the existing two stacks of DCH1 and in comparison to • Sensitivity of visual receptor - moderate. the 1,800MW CCGT-only scheme, reduce the apparent mass of the building above the skyline. There • Visual impact – slight adverse (not significant). is also a slight reduction in horizontal massing from Assessment with Kingsnorth Power Station removed: this angle of view, although the overall appearance Kingsnorth Power Station is the primary focal point in this part of the and massing of built form below the skyline is very view, with DHC1 appearing as a secondary focal point. With the similar to the currently consented 1,800MW scheme. removal of the Kingsnorth Power Station, the extent of the developed As with the 1,800MW CCGT-only scheme, the scale of skyline will be reduced. DHC1 will become the main focal point in the stacks and air cooled condenser building will this part of the view although its main built elements appear below appear to be slightly larger than the massing of the the skyline. existing Damhead Creek CCGT Power Station which The 1,800MW Variation is located to the fore and immediate left of reinforces its perception as a closer building. The the existing Damhead Creek CCGT Power Station and slightly range of approximately 4.3km, further moderates the increases the horizontal extents of development in this part of the impact of the changes as it is perceived as a minor view. The scale of the 95m stacks and air cooled condenser building element of a larger horizontal expanse in a part of the will appear to be slightly larger than the massing of the existing view already influenced by similar development with Damhead Creek CCGT Power Station which reinforces its the existing DHC1 and in the wider view with the Isle perception as a closer building. The range of approximately 4.3km, of Grain Power Station to the east. further moderates the impact of the changes as it is perceived as a The visual impact will remain slight to moderate minor element of a larger horizontal expanse in a part of the view adverse and the overall effect will be not significant. already influenced by similar development. The visual impact will be slight to moderate adverse and the overall effect will be not significant.
Viewpoint 7 – Stoke Road, Stoke Village Viewpoint 7 – Stoke Road, Stoke Village (Assessment • DHC2 located between existing Kingsnorth and Damhead Creek with Kingsnorth Power Station removed) Power Stations but at range of approx. 2.2 km DHC2 will appear The proposed 1,800 MW CCGT with peaking plant as a relatively large scale features in the view, although scheme is located in a similar location to the 1,800MW moderated by influence of existing power stations. Taller (95 m) CCGT-only scheme - to the fore and immediate left of stacks will be more prominent. DHC1. The two main stacks repeat the existing two • Sensitivity of visual receptor - moderate. stacks of DHC1 and in comparison to the currently consented scheme, reduce the apparent mass of the • Visual impact – moderate adverse (significant) building above the skyline. Similar to the currently Assessment with Kingsnorth Power Station removed: consented scheme, the proposed 1,800 MW CCGT The overall massing and scale of industrial built form in the view will with peaking plant scheme will appear as a relatively diminish with the removal of Kingsnorth Power Station. As a result, large scale feature in the view, moderated by the the view will appear less ‘cluttered’ with development appearing to presence of DHC1 and the closer range pylons. The be contained between the pylon in the mid-ground, and the road. stacks will appear taller in height than the existing The 1,800MW Variation is seen to the left of DHC1, at slightly closer stacks of DHC1 to the right but will present a uniform proximity to the viewpoint. At a range of approximately 2.2km, the composition with the mass of the air cooled condenser 1,800MW Variation DHC2 will appear as a relatively large scale and other components lying between the two pairs of feature in the view, albeit moderated by the presence of the existing stacks (DHC1 and proposed). DHC1 and the closer range pylons. The stacks will appear taller in The visual impact will remain moderate adverse and height than the existing stacks of DHC1 to the right. The mass of the the effect will be significant. air cooled condenser, building and other components infill this space and add to the density of the overall development. The 1,800MW Variation will appear to replicate the elements in the existing view at a closer range. The visual impact will be moderate adverse and the effect will be significant.
Viewpoint 8 – Turnbridge Hill, Stoke Road Viewpoint 8 – Turnbridge Hill, Stoke Road • Footprint of 1,800 MW CCGT-only scheme option increases (Assessment with Kingsnorth Power Station removed) horizontal extent of development, and appears more prominent The proposed 1,800 MW CCGT with peaking plant due to slightly closer range and larger scale of stacks, which scheme is also located to the left of DHC1. The
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may be viewed at full height rather than being partially composition and massing of built elements in the concealed by other elements of the DHC2 development. proposed scheme is slightly reduced in comparison • Sensitivity of visual receptor - moderate. with the 1,800MW CCGT-only scheme. In particular, the air cooled is smaller in scale and is located to the • Visual impact – moderate adverse (significant) centre of the view and the three stacks are replaced Assessment with Kingsnorth Power Station removed: with two. Pairs of stacks repeat in the proposed 1,800 Kingsnorth Power Station is located behind DHC1 in the view. The MW CCGT with peaking plant scheme with two smaller removal of the Kingsnorth Power Station will reduce the massing of stacks for the proposed peaking plant. In common with buildings and the stack height in the overall composition of large the CCGT only scheme, the proximity of the proposed scale industrial elements. 1,800 MW CCGT with peaking plant scheme to the The 1,800MW Variation is located to the left of DHC1. The air cooled existing power station ensures that it appears as an condenser and stacks appear slightly larger but comparable in scale extension, and this clustering helps to contain the to the similar components of DHC1. The proximity of the 1,800MW effects of these developments within a localised area. Variation to the existing power station ensures that it appears as an The proposed 1,800 MW CCGT with peaking plant extension, and this clustering helps to contain the effects of these scheme will be seen as part of an area already developments within a localised area. characterised by large scale power station development and this moderates the overall impact. The 1800MW DHC2 will be seen as part of an area already characterised by large scale power station development and this The visual impact will remain moderate adverse and moderates the overall impact. the effect will be significant. The visual impact will be moderate adverse and the effect will be significant.
Cumulative Effects
The 2009 ES7considered the potential cumulative effects of DHC2 in The decommissioning of Kingsnorth Power Station conjunction with the proposed supercritical coal fired power station at (Units 1-4) has been completed. However the Kingsnorth Units 5 and 6 and the Kingsnorth Business Park. programme for demolition is scheduled to continue to Cumulative effects were not considered to be significant. By the time 2018, according to information submitted in support of of publication of the 2014 EIR8, the development of Kingsnorth Units the Prior Notification for Proposed Demolition 5 and 6 had been shelved and, as a result, no cumulative effects application submitted to Medway Council. It has were predicted. therefore been taken into account in the assessment In views from the north and east, the Kingsnorth Business Park of cumulative effects. would extend the industrial setting for DHC2 and would, as a No changes to the potential cumulative effects are consequence, reduce the prominence of DHC2. The Kingsnorth envisaged. Business Park would be partially screened in views from the west by the existing developments in the area. In views from the south, the lower (shorter) level Kingsnorth Business Park development would not increase the impact of DHC2, as it would be barely visible. Overall, the 2014 EIR anticipated the cumulative effect of DHC2 and the proposed Kingsnorth Business Park Development would not be significant. At the time of the 2015 EIR9 publication, the decommissioning of the existing Kingsnorth Power Station (Units 1-4) had commenced. However no changes to the potential cumulative effects were envisaged.
Mitigation Measures
Construction Construction A CEMP will be prepared in support of the 1,800 MW scheme,to All measures proposed for the 1,800 MW CCGT-only include the following: scheme option would be applied and implemented • temporary storage of topsoil and any other material considered through an updated CEMP, no matter which option is of value for retention; progressed. No additional mitigation measures are considered to be required. • temporary protection measures for vegetation and other features associated with the site construction in accordance with current industry standards and recognised best practice;
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• design and layout of site constructing areas including the location and type of temporary security fencing and lighting; and • agreed site access routes and measures for the protection and, where necessary, re-instatement of verges, vegetation and other landscape features on routes used by construction traffic. All areas affected by temporary site construction operations will be re-instated in accordance with a restoration plan. The restoration plan has been agreed with Medway Council including: • method statements for the restoration of areas affected by construction to an agreed after use and to an agreed timescale; and • a Management Plan for reinstated areas to include any measures for the vegetation establishment and planned long- term stewardship. The 2015 EIR also identified that approved Landscape and Habitat Management Plan (restoration plan)16 will be reviewed and updated, as necessary
Operation Operation The 1,800 MW scheme will be similar in scale, design and layout to The scale, design and layout of the proposed the existing Damhead Creek CCGT Power Station. It will be located 1,800 MW CCGT with peaking plant scheme option adjacent to the existing power station, and will appear as an will be similar to the 1,800 MW CCGT-only scheme extension to it. option and will appear as an extension to the adjacent A recessive colour scheme, identical to that used on the existing existing Damhead Creek CCGT Power Station. A Damhead Creek CCGT Power Station will be used in order to break similar, recessive, colour scheme will be used. The up the impact of the built structures as shown on the photomontages artificial lighting scheme will be similar to the existing provided in the 2015 EIR.9 Damhead Creek CCGT Power Station, in line with current best practice and industry standards and will The scheme will include site lighting and emergency lighting, road comply with Section 90 Direction Condition 8. lighting and area flooding lighting. Lighting systems and design will be similar to those used on the existing Damhead Creek CCGT Landscape mitigation planting would be unlikely to Power Station. Lighting systems will comply with current best achieve a significant reduction in the visual impact of practice and industry standards as required by Section 90 Direction the 1,800 MW scheme due to its scale. Extensive tree Condition 8. and shrub planting would also be out of character with the local landscape of the Medway marshes. There is existing landscape mitigation, principally on the northern Landscape planting can, however, be effective in perimeter of the existing Damhead Creek CCGT Power Station. This reducing visual impact from near views. It is, therefore, mitigation combines shallow mounding (up to 3 m in height) with proposed to extend the mounding and planting areas of native planting. Whist much of the planting has established associated with the existing Damhead Creek CCGT it has not achieved significant heights and has more the character of Power Station to the northern edge of the DHC2 site areas of dense scrub. This mounding and planting will be effective in (no matter which scheme option is taken forward for screening low level plant and security fencing from near views implementation). around the application site. The mounding is similar in scale and height to the flood protection bund to the Medway Estuary. The approved Landscape and Habitat Management Plan (restoration plan)16 will be reviewed and updated, Landscape mitigation planting would be unlikely to achieve a as necessary, to ensure that the larger footprint of the significant reduction in the visual impact of the 1,800 MW scheme proposed 1,800 MW CCGT with peaking plant scheme due to its scale. Extensive tree and shrub planting would also be out option is accommodated within the restoration of character with the local landscape of the Medway marshes. proposals. Landscape planting can, however, be effective in reducing visual impact from near views. It is, therefore, proposed to extend the mounding and planting associated with the existing Damhead Creek CCGT Power Station to the northern edge of the DHC2 site. The Landscape and Habitat Management Plan (restoration plan)16 submitted to Medway Council detailed the proposed planting and other landscape features to be provided principally in the area to the immediate north, north-east and east of the application site. The Landscape and Habitat Hanagement Plan was approved by the
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1,800 CCGT-only MW Scheme Proposed 1,800 MW CCGT with peaking plant Scheme option
Council on 4 February 2014 pursuant to planning reference MC/13/3309. The plan included proposals to extend tree planting and earth bunds further along the access road to the power station to the north of the DHC2 scheme. Along the eastern boundary, the security fence is proposed to be located at the foot of a steep slope to reduce its visual impact in local views. Much of the proposed planting to the north-east and east comprises low scrub and hedgerows as well as small scale ponds. These would be in keeping with the local landscape character and will provide a more natural setting. However, they would have little effect in screening the components of the DHC2 scheme from surrounding receptors and will not mitigate the wider impacts on landscape character and visual amenity across the wider local area.
6.4.5 Conclusions The assessment concludes that the landscape and visual impact will be similar to that detailed in the ES. The proximity of the proposed 1,800 MW CCGT with peaking plant scheme to the existing power station DHC1, ensures that it appears as an extension, and this clustering will help to contain the effects of the developments within a localised area.
There have been some slight increases in the impacts assessed for the 1,800 MW CCGT with peaking plant scheme when it is considered in the context of the Kingsnorth Power Station having been removed. However these impacts would also arise with the consented 1,800 MW CCGT-only scheme option. The changes manifested in the proposed 1,800MW CCGT with peaking plant scheme slightly reduce the horizontal spread in some views, but do not alter the overall conclusions on the significance of effects.
The significant effects, assessed in respect of the two closest of the representative viewpoints, remain the same for the proposed 1,800 MW CCGT with peaking plant scheme option as for the consented 1,800 MW CCGT-only scheme option.
The exact dimensions, colours and materials will be agreed with Medway Council prior the commencement of construction, in order to achieve the fullest possible integration of the proposed 1,800 MW CCGT with peaking plant scheme option within the surrounding environment. Lighting systems will also comply with current best practice and industry standards as required by Condition 8.
Moreover, the Report entitled “Planning Conditions Discharge Summary: Landscape and Creative Conservation (Conditions 38 - 41) Issue 1.0 - Final" (dated 16 December 2013) approved by the Council on 4 February 2014, pursuant to planning reference MC/13/3309, details the proposed planting and other landscape features to be provided. This is principally in the area to the immediate north, north-east and east of the proposed development site. The proposal is to extend tree planting and earth bunds further along the access road to the power station to the north of the proposed 1,800 MW CCGT with peaking plant scheme. Along the eastern boundary, the security fence will be located at the foot of a steep slope to reduce its visual impact in local views. Much of the proposed planting to the north-east and east comprises low scrub and hedgerows as well as small scale ponds. These will be in keeping with the local landscape character and will provide a more natural setting. However, they will have little effect in screening the larger components of the development from surrounding receptors and will not mitigate the impacts on landscape character and visual amenity across the wider local area.
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6.5 Ecology 6.5.1 Introduction This section considers the potential changes to effects on valued ecological receptors (VERs) during construction and operation of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the 1,800 MW CCGT-only scheme option. The Statement to Inform in relation to Habitats Regulations Assessment is provided in Appendix H. 6.5.2 Baseline Conditions The baseline conditions section of the 2009 ES ecological assessment (Chapter 13, 2009 ES7) was based upon detailed desk based study and subsequent field studies. Surveys undertaken to inform the 2009 ES, comprised:
• Phase 1 Habitat survey (2006 and 2007);
• invertebrate surveys of terrestrial and aquatic habitats (2006);
• great crested newt (GCN) survey (2006 and 2007);
• reptile survey (2006 and 2007);
• breeding bird survey (2007);
• wintering and passage bird surveys (2007 and 2007);
• wintering bird survey (2008 and 2009);
• preliminary daytime bat surveys, followed up with evening surveys (2006); and
• water vole survey (2001 - 2006); and
• badger survey (2006).
The 2009 ES also drew upon ecological information available in surveys undertaken in relation to the neighbouring proposals for Kingsnorth Business Park, which at the time included assessment of the land located in Areas 2 and 3 of the application site and also land further to the east of the application site.
Since the submission of the 2009 ES, additional ecological field studies have been undertaken to discharge planning conditions 42, 43 and 44 of the Section 90 Direction and planning permission ref. MC/12/2356 for the change of use of part of the Wetland Creation Area (WCA). These comprise:
• breeding bird surveys (2009, 2011, 2013 and 2015);
• botanical survey (2015);
• amphibian (including GCN) surveys (2011, 2012, 2013, 2014 and 2015);
• water vole survey (2009, 2011, 2013 and 2015);
• reptile surveys (2012, 2013 and 2014);
• badger surveys (2012 and 2013);
• invertebrate survey (2014); and
• harvest mouse surveys (2014).
Overview of the Application Site and Surroundings The application site is situated on the southern edge of the Hoo Peninsula, which lies between the Thames and Medway Estuaries.
To the south of the application site lies the site of the former Kingsnorth Power Station (Kingsnorth Units 1 to 4), which comprises hardstanding surfaces and smaller areas of habitat including semi-improved
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neutral and amenity grasslands with scattered trees and shrubs. To the north lies the existing Kingsnorth Industrial Estate and to the west the existing Damhead Creek CCGT Power Station.
The south and eastern margins of the application site are bounded by drainage ditches, which flow into Damhead Creek itself. Damhead Creek flows north-east and east from the application site, into East Hoo Creek, which subsequently flows into the River Medway, approximately 2 km east of the application site boundary.
The area surrounding the application site is characterised by the mudflats and wetland margins of the Medway Estuary, in addition to several industrial developments. The industrial developments include large sites at the Isle of Grain, located approximately 5 km north east of the application site. An industrial railway line runs west-east across the Hoo Peninsula, passing approximately 750 m north of the application site at its nearest point, and several minor roads connect the industrial sites and small hamlets and farmsteads to the nearby town of Hoo St. Werburgh (approximately 3 km west of the application site) and to the A228 (to the north and west of the application site) and other major road networks in the local area.
Statutory and Non-Statutory Sites of Nature Conservation Interest The Medway Estuary and Marshes, which is designated as a Site of Special Scientific Interest (SSSI), Special Protection Area (SPA) and Ramsar site, is located adjacent to Area 2 of the application site. In addition, three SPAs, three Ramsar sites, one Environmentally Sensitive Area (ESA), eight SSSIs and one National Nature Reserve (NNR) occur within 10 km of the application site boundary. Details of these sites are summarised below in Table 6.5.1.
Table 6.5.1: Statutory Designated Sites within 10 km of the Application Site
Designated Site Size (ha) Distance from Application Site
Medway Estuary and Marshes SPA 4,684 Adjacent
Medway Estuary and Marshes Ramsar Site 4,697 Adjacent
Medway Estuary and Marshes SSSI 6,840 Adjacent
Dalham Farm SSSI 9 4 km north-west
Tower Hill to Cockham Wood SSSI 47.9 4 km west
Northward Hill SSSI and High Halstow NNR 52.5 4 km north-west
Chattenden Woods and Lodge Hill SSSI 351 3.5 km north-west
Thames Estuary and Marshes Ramsar Site 5,588 6 km north-west
Thames Estuary and Marshes SPA 4,839 6 km north-west
South Thames Estuary and Marshes SSSI 5,449 6 km north-west
Queendown Warren SAC 14 10 km south
Queendown Warren SSSI 22 10 km south
Benfleet and Southend Marshes Ramsar site 2,251 10 km north
Benfleet and Southend Marshes SPA 2,251 10 km north
Benfleet and Southend Marshes SSSI 2,099 10 km north
There are several sites of ancient woodland within 5 km of the application site boundary, as follows:
• two areas near Fenn Street, approximately 2.5 km north-west of the application site;
• six areas in and around Chattenden Woods and Lodge Hill SSSI (the closest of these sites is approximately 3 km to the west of the application site); and
• at Tower Hill to Cockham Wood SSSI, approximately 4 km south-west of the application site.
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Habitats and Flora The following broad habitats are present within the application site:
• semi-improved grassland (Neighbourhood importance);
• waterbodies including ponds, ditches, saline/ brackish lagoons, and associated marginal habitats (County importance);
• scattered scrub (Neighbourhood importance);
• dense scrub (Neighbourhood importance);
• ruderal (Neighbourhood importance);
• sparse vegetated ground (Neighbourhood importance; and
• hardstanding/ gravel (Neighbourhood importance).
Protected and Notable Species A number of protected/ notable species occur on the DHC2 site and surrounding area:
• badger (Local importance);
• water vole (Local importance);
• bats (Local importance);
• breeding birds (County importance);
• wintering birds (International importance);
• reptiles (District importance);
• amphibians (Local importance);
• terrestrial invertebrates (Local importance); and
• aquatic invertebrates (Local importance).
Summaries of the protected and notable species surveys conducted in relation to the DHC2 project are presented in Tables 6.5.2 to 6.5.4 below.
Table 6.5.2: Summary of the Findings of the Ecological Surveys Undertaken in Support of the 2009 ES
Species Findings Value
Badger No sets were identified within 30 m of the boundaries of the application site. However, Local evidence such as a fresh latrine, badger hair found on a gate and identified runs suggested that badgers were commuting within the application site. Low levels of use and no setts present.
Water vole Water vole surveys have been undertaken across the area between 2001 and 2005. When Local considered as a whole, the results of the surveys indicate that the water vole population remains stable. The ditches adjacent to the application site and the connected ditches in the wider area are known to support a large population of water vole. Abundant in the area. Legal protection afforded to the species and their habitats will require consideration.
Bats The surveys found there to be a low level of bat use in the application site. Local Low levels of use across the Damhead Creek 2 site and no roosts present. Legal protection afforded to the species will require consideration.
Breeding birds Surveys undertaken in April, May and June 2007 included Targeted Surveys for Barn Owl, County
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Species Findings Value
Black Redstart, Harrier Species, Peregrine and Nightingale. No breeding species included on the Medway Estuary and Marshes SPA citation were recorded. However, a number of species of conservation interest were identified, including: Barn Owl, Marsh Harrier; and Cetti’s Warbler. A number of breeding species of conservation concern present. The assemblage comprises an area wider than the application site. All breeding birds receive protection under the Wildlife & Countryside Act 1981 (as amended).
Spring No passage migrants were recorded and the application site is considered to be of less than N/A passage Neighbourhood importance for migratory birds. Spring passage migrant birds are not migrant bird considered further in this assessment.
Wintering The survey findings were found to be in keeping with other surveys undertaken by third parties Inter- waterbirds and Wetland Bird Survey (WeBS) Data, which identified that the intertidal areas adjacent to the national application site are used as a feeding area by a wide variety of wetland birds, with some being present in significant numbers at times and including species listed in the Medway Estuary and Marshes SPA/ Ramsar citation. The 2008/9 surveys identified 14 species of waterbirds regularly using the survey area at high and/or low tide. These included black-tailed godwit coot curlew, greenshank, lapwing, little egret, little grebe, mallard, redshank, shelduck, shoveler, teal, tufted duck, wigeon. The surveys indicated that the footprint areas and hinterlands of the proposed 1,200 MW scheme are only used by small numbers of waterbirds and do not support important high tide roosts. However, it is considered that development activities in the area could result in indirect effects. Component feature of the European designated site this receptor is considered in conjunction with the Medway Estuary SPA/Ramsar.
Reptiles Area 1 is of greatest importance to reptiles principally due to the habitat suitability and District proximity to the WCA. The remaining areas were considered to be of much lower importance for reptiles based on the findings on the reptile surveys and existing habitat conditions. Common lizard and slow worm are present in relatively high numbers. Legal protection afforded to the species will require consideration.
Amphibians The WCA adjacent to Area 1 supports great crested newts. Furthermore, the grassland Local (great crested habitats within Area 1 potentially provide foraging habitat for GCN. newt) Small breeding great crested newt population within 500 m of the application site. Legal protection afforded to the species and their habitats will require consideration.
Terrestrial The invertebrate fauna across the application site and, more significantly, the wider area, Local invertebrates reflects the site’s coastal location in north Kent, on the edge of the broader East Thames corridor. There are coastal species, species typical of wetland habitats and ponds, and species typical of species rich grassland and brownfield sites, as would be expected given the habitats present and recent site origin. Species typical of the region and habitats present.
Aquatic The species found during the surveys on the application site are not protected under existing Local invertebrates legislation. Species typical of the region and habitats present.
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Table 6.5.3: Summary of the Findings of the Ecological Surveys Undertaken Subsequent to the Section 90 Direction
Species Survey Date Summary / Findings
Great crested 2011, 2012, 2013, Surveys of 12 monitored ponds at the now operational Damhead Creek CCGT newt 2014 and 2015 Power Station in accordance with the Habitat Species Monitoring Programme. Counts were as follows: • 2011 – 76; • 2012 – 21; and • 2013 – 24. No GCN were recorded in the 2015 survey but this reflects the actual waterbodies surveyed. The WCA, that had recorded significant GCN populations in previous surveys were not surveyed in 2015 due to ongoing habitat manipulation and herptile translocation works being carried in the WCA during that period. Approval was secured from Natural England for licences to translocate water voles and GCN from the former WCA to new larger areas of mitigation land. GCN trapping in spring/summer 2015 resulted in 997 GCN and 9 water voles being caught and translocated to the new mitigation land. The works, undertaken under licences (Licence EPSA2012-5318 version E, dated 14th April 2015) and (2015-9387-SCI- SCI-1, dated 23rd April 2015) has been completed.
Water vole 2009, 2011, 2013 and Survey area included the application site, including the former WCA. Nine water 2015 bodies were surveyed. In four of the nine water bodies. No water vole activity signs were recorded. Signs were recorded in all other water bodies surveyed with field signs recorded generally every 5 m or less along the bankside. 2015 surveys noted that overall the frequency of water vole signs appears to have stayed similar to 2013 levels, except for the Berry Wiggins Dran (BWD) where numbers have increase. As set out above, water vole translocation has been undertaken alongside GCN translocation as part of the creation of new mitigation land.
Reptiles 2012 2012 presence/absence survey recorded three species of reptile (slow-worm, Updated 2013 viviparous lizard and grass snake) within the WCA. 2013 presence/absence survey concluded that the site holds low (small) populations of slow-worm and viviparous lizard.
Badger 2012 and 2013 Survey area included the application site, including the adjacent WCA. No badger setts were present within the Mitigation Area in 2012 and no badger signs were recorded on the land proposed for the DHC2 development.
Table 6.5.4: Summary of the Findings of the Ecological Surveys and Monitoring Undertaken in Support on the WCA Change of Use Consent
Species Survey Date Summary / Findings
Harvest 2014 Harvest mice were found to be present, with the ditch habitat holding the higher mouse populations. One nest was recorded around the ponds and two were recorded within 50 m of the ditch habitat. The report recommended that, where possible existing habitats are left in situ during development works. Where this is not possible new suitable habitats, perhaps supported by translocation of appropriate vegetation from the survey area, are incorporated into nearby mitigation habitat.
Invertebrates 2014 Overall, 326 species of invertebrate were recorded within the survey area, including 1no ‘near threatened’, 1no ‘rare’ and 11no ‘nationally scarce’ species. This is considered to be a relatively high species count for a single site in Kent. The report includes a number of outline habitat recommendations for each species
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Species Survey Date Summary / Findings
and the following, more general conservation recommendations: • maintain diverse flora; • retain or create areas of bare soil; • retain or recreate areas of open water, from which large fish are excluded; and • where possible, existing habitats should remain in situ during development but where this is not possible new suitable habitats, perhaps supported by translocation of appropriate vegetation from the survey area, must be incorporated into mitigation proposals.
Reptiles 2014 The survey comprised 7 site visits, which found that the area holds a Moderate/High population of viviparous lizard and slow-worm and a Low (small) population of grass snake. The report states that a reptile translocation and mitigation programme is required prior to development of the survey area. As a probable Moderate/ High Population of reptiles was evident, this translocation programme is likely to encompass over 90 site visits to the Donor site with animals being transferred to a nearby prepared Receptor area. Prior to translocation, any vegetation clearance work on site required to examine services or archaeology will need to avoid harming reptiles and any clearance of herbaceous vegetation should be overseen by a suitably qualified ecologist. As Great Crested Newts are known to be on site this ecologist must be licenced for this species.
Amphibian – 2015 See Table 6.5.3 regarding survey findings and translocation works underway. including Great Crested Newt (GCN)
Water Vole 2015 See Table 6.5.3 regarding survey findings and translocation works underway.
Breeding Birds 2015 Surveys undertaken between May and July 2015 followed a similar methodology to the 2009, 2011 and 2013 surveys but involved three rather than two recording visits, which ensured that all parts of the site were covered during the survey visits. For target species, in 2015, as in 2013, sixty four bird species were recorded acorss the combined mitigation and nearby land areas. This compares to 50 speices in 2011 and 69 species in 2009.
Botanical 2015 Surveys were undertaken on two occasions in the summer of 2015 (1st June and Monitoring 20th August) and surveyed for the presence of Nationally Scarce and local rare plants. The report concludes that overall 6 of the 7 Scarce Plant Species recorded in 2001 were observed in 2015, an additional four Other Locally Important Plant species located on the site in 2011 were recorded in 2015 (including Carex muricata which had not been observed in 2013), and the distribution of Scarce Plant populations on the mitigation areas continues to change dueto changes in local vegetation cover and to levels of soil disturbance with Other Locally Important Species appearing to have generally maintained distributions in line with those recorded in 2013.
Summary of VERs for Ecological Assessment The VERs identified for assessment are:
• Medway Estuary and Marshes SSSI, SPA and Ramsar site and associated bird populations;
• all other European and nationally designated sites within the study area (see Table 6.5.1);
• water bodies including ponds, ditches, saline/brackish lagoons and associated marginal habitats;
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• badger;
• water vole;
• bats;
• breeding birds;
• reptiles;
• amphibians;
• terrestrial invertebrates; and
• aquatic invertebrates. 6.5.3 Differences Between Proposed Scheme Options The following differences between the proposed 1,800 MW CCGT with peaking plant scheme option and the already consented 1,800 MW CCGT-only option have been taken into account in the assessment:
• emissions to air (including dust) during construction and operation; and
• noise, vibration and lighting during construction and operation.
Ecological Enhancement As discussed in Section 4.3, a scheme of ecological enhancements has now been implemented, including water vole habitat creation, capture and translocation of water voles and GCN. The GCN and water vole translocation programme has recently been completed with 997 GCN and 9 water voles successefully captured and translocated to the new WCA under licences approved by Natural England (Licence EPSA2012-5318 version E, dated 14th April 2015) and (2015-9387-SCI-SCI-1, dated 23rd April 2015). 6.5.4 Appraisal of Environmental Impacts and Mitigation Table 6.5.5: Appraisal of Ecology Effects
1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Construction
The construction works associated with DHC2 are predicted to All construction works will be carried out in accordance result in the following potential impacts to VERs: with Section 90 Direction Conditions 8, 11, 12, 13, • permanent and temporary habitat loss within the site; including the preparation of an updated CEMPand will not result in the direct loss of habitat in any designated sites. • direct mortality during site clearance and construction; With the exception of the Medway Estuary and Marshes • direct and indirect disturbance from construction activities SSSI/ SPA/ Ramsar site, the designated sites are located including visual, noise, dust and lighting; sufficiently far away from the application site as to be • degradation of adjacent habitats of conservation unaffected by any potential negative impacts from pollution importance; and or disturbance from the construction period. • pollution caused by use of hazardous materials and release The proposed 1,800 MW CCGT with peaking plant of waste materials. scheme option will utilise the same development footprint During the construction phase, no direct loss of habitat to any as the CCGT-only option, with part of Area 3 still required designated sites will occur as a result of DHC2. It is considered to accommodate the main plant. This option does not that, with the exception of the Medway Estuary and Marshes require quite as much area for the main development as SSSI/ SPA/ Ramsar site, the designated sites are located the CCGT-only scheme options but for simplicity and to sufficiently far away from the DHC2 site as to be unaffected by ensure same CCS land retained, we have allocated the any potential negative impacts from pollution or disturbance from same area as the CCGT-only option. This will not result in the construction period. any significant alterations to the proposed ecological The impact of construction noise on VERs is not predicted to be habitat creation in Area 3 which will be maintained. significant. The potential effect of noise and vibration on ecological
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Vibration from compacting, breaking or piling activities receptors is considered in Section 6.3. associated with the construction is not predicted to be sufficient No additional potential impacts have been identified for the to propagate from the site. construction phase of the 1,800 MW CCGT with peaking All construction works will be carried out in accordance with plant scheme option compared to the 1,800 MW CCGT- Conditions 8, 11, 12 and 13 of the Section 90 Direction including only scheme option. the preparation of a Construction Environmental Management Plan (CEMP). As discussed in Section 6.4, a Landscape Masterplan16 has been prepared, which includes a habitat mitigation scheme to account for the loss of existing habitat. The 2015 EIR identified that the 1,800 MW CCGT-only scheme option would require part of the main plant to accommodate part of Area 3. The 2015 EIR9 concluded that this would not result in any significant alterations to the proposed ecological habitat creation in Area 3 as the slight encroachment into the mitigation area shown on the indicative layouts (2015 EIR - Figures 6a and 6b) would be rectified by the final layout.
Designated Sites Designated Sites All European Sites are assigned an international value and No potential effects on designated sites, with the exception nationally designated sites assigned a national value. No direct of Medway Estuary and Marshes SSSI/ SPA/ Ramsar site, loss of habitat to any designated sites is predicted to occur as a are predicted. result of the 1,800 MW CCGT-only scheme option. The main plant of the proposed 1,800 MW CCGT with With the exception of Medway Estuary and Marshes SSSI/ SPA/ peaking plant scheme option will have a slightly smaller Ramsar site, it is considered that there is no potential for footprint than the 1,800 MW CCGT-only scheme option, significant effects due to their distance from the application site. but the distance of the plant from the Medway Estuary and The effects of the construction works on the Medway Estuary Marshes SSSI/ SPA/ Ramsar site will remain the same. It and Marshes SSSI/ SPA/ Ramsar site are predicted to be of is considered that the proposed mitigation (including medium magnitude and significant at an International level. implementation of a CEMP and noise mitigation as discussed in Section 6.3) is sufficient to avoid the potential In addition, the potential effects of pollution and degradation to for any greater effects. The potential effect on Medway the Medway Estuary and Marshes SSSI/ SPA/ Ramsar site Estuary and Marshes SSSI/ SPA/ Ramsar site remains during the construction process were also considered to be of significant at an international level, but mitigation will be medium magnitude and significant at an International level. implemented to minimise the risk of any impact occurring. The 2015 EIR9 noted that the larger footprint of the 1,800 MW CCGT-only scheme option would require construction of the plant closer to the Medway Estuary and Marshes SSSI/SPA/Ramsar site. However the proposed mitigation (including implementation of a CEMP and noise mitigation as discussed in Section 6.3 of the 2015 EIR) would be sufficient to avoid the potential for any greater effects. The 2015 EIR concluded that the potential effect on Medway Estuary and Marshes SSSI/ SPA/ Ramsar site would remain significant at an international level, but mitigation would be implemented to minimise the risk of any impact occurring.
Habitats Habitats Water bodies including ponds ditches, saline/ brackish lagoons The areas proposed to be landscaped and used as habitat and associated marginal habitats were considered to be of mitigation in the Landscape Masterplan16 will not be County value. Potential construction impacts could be affected by the footprint required for the proposed associated with habitat degradation and pollution. 1,800 MW CCGT with peaking plant scheme option. The No temporary or permanent loss of water bodies in Area 2 is approved Landscape and Habitat Management Plan proposed to occur as a result of construction. (restoration plan) will be reviewed and updated, if necessary. The 1,200 MW scheme necessitated the permanent loss of part of the WCA and selected waterbodies therein. The Landscape The adverse impacts related to the proposed 1,800 MW Masterplan includes a habitat management scheme to account CCGT with peaking plant scheme option, based on the habitat features alone and not associated fauna, is
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
for this loss. The 2015 EIR identified the approved Landscape considered to be of medium magnitude and significant at a and Habitat Management Plan would be reviewed and updated, County level, as with the CCGT-only scheme option. if necessary. The adverse impacts based on the habitat features alone and not associated fauna, was considered to be of medium magnitude and significant at a County level.
Species Species The 2015 EIR9 identified that with the exception of a thin strip of land adjacent to the existing ditch (which could be affected The water vole and GCN translocation process has been based on the indicative layouts shown in Figures 6a and 6b completed with 997 GCN and 9 water voles translocated in (2015 EIR)), the areas proposed to be landscaped and used as Spring 2015. habitat mitigation in the Landscape Masterplan would not be The impacts of the proposed 1,800 MW CCGT with affected by the increased footprint required for the 1,800 MW peaking plant scheme option will not be significantly CCGT-only scheme option. Nevertheless, the approved different to the previously assessed 1,800 MW CCGT-only Landscape and Habitat Management Plan (restoration plan)16 scheme option. As such no change to the previous would be reviewed and updated, as necessary It concluded that conclusions regarding impacts on species are predicted. no change to the previous conclusions regarding impacts (detailed below) on species were predicted. Badger, water vole, bats, amphibians, terrestrial and aquatic invertebrates are assigned a Local value. Breeding birds are assigned a County level. Intertidal birds are assigned an International value, as they are a component feature of the Medway Estuary and Marshes SSSI/ SPA/ Ramsar site. Due to relatively high numbers of reptiles, a District value has been assigned. Badger The magnitude of the impact due to loss of foraging habitat for badger is considered to be negligible and therefore not significant. The potential impacts on commuting badgers is assessed as being of low magnitude and significant at a Local level. Mortality of badgers during construction activities would have a low magnitude impact and is considered to be significant at a Local level. Water vole The 2015 EIR9 noted the potential for permanent loss of selected water bodies within Area 3 would result in permanent loss of water vole habitat equating to a negative effect of medium magnitude and significant at a Local level. Since the publication of the 2015 EIR the the number of water bodies in Area 3 has increased. The impact upon the water vole population in Area 1 in the 2015 noted a potential impact would result in a negative effect of low magnitude and significant at a Local level. Since the publication of the 2015 EIR the GCN and water vole population has been moved to the newly created mitigation area as part of the translocation programme, under licences approved by Natural England (Licence EPSA2012-5318 version E, dated 14th April 2015) and (2015-9387-SCI-SCI-1, dated 23rd April 2015). The potential effects of habitat fragmentation are considered to be of medium/ high magnitude and could extend beyond the DHC2 site. The potential impact is considered to be significant at a District level. Disturbance to water voles during the construction activities may include visual, noise, dust and lighting. These potential impacts
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would result in a negative effect of low magnitude and significant at a Local level. Mortality of any water voles as a result of the construction activities would be a negative effect of low magnitude (with the potential to escalate if a number of water voles were affected) and significant at a Local level. Bats The permanent loss of selected water bodies within Area 3 will result in permanent loss of bat foraging habitat and likely commuting corridor features equating to a negative effect of medium magnitude and significant at a Local level. Temporary lighting can cause a barrier through which bats will not pass. The effects of this impact are likely to be of low magnitude and as such significant at a Local level. Birds (not associated with the Medway Estuary and Marshes SSSI/ SPA/ Ramsar site) Permanent loss of habitat (Area 1) which provides foraging for barn owl and, to a lesser extent, marsh harrier, will result in a high magnitude of impact and is significant at a County level. Visual, noise/ vibration, lighting and dust disturbance during construction activities could result in a negative effect of medium magnitude, which would be significant at a County level. Bird mortality resulting from construction activities would be of at least low magnitude (species dependent being higher for rarer species) and significant at a County level. Reptiles Permanent habitat loss is considered to be of medium magnitude and significant at a District level. The layout of the 1,800 MW scheme is considered to be unlikely to present a barrier to commuting reptiles and is therefore considered to be negligible and not significant. Visual, noise/ vibration, lighting and dust disturbance during construction activities could result in a negative low magnitude of impact which would be significant at a District level. Reptile mortality resulting from construction activities would be of low magnitude at a District level. Amphibians Permanent loss of foraging and hibernating habitat was considered to be negligible and not significant. The layout of the 1,800 MW scheme was considered to be unlikely to present a barrier to great crested newts and was therefore considered to be negligible and not significant. Visual, noise /vibration, lighting and dust disturbance during construction activities could result in a negative low magnitude of impact which would be significant at a Local level. Great crested newt mortality resulting from construction activities would be of low magnitude and significant at a Local level. Since the publication of the 2015 EIR9 the GCN and Water vole population has been moved as part of the translocation programme, under licences approved by Natural England (Licence EPSA2012-5318 version E, dated 14th April 2015) and (2015-9387-SCI-SCI-1, dated 23rd April 2015).
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Terrestrial Invertebrates The permanent loss of habitat to terrestrial invertebrates is considered to be of low magnitude and significant at a Local level. The 1,800 MW scheme is unlikely to comprise a barrier effect to terrestrial invertebrates and this potential impact is considered to be negligible and as such not significant. Disturbance to terrestrial invertebrates during the construction activities may include visual, noise, dust and lighting. These potential impacts could result in a negative effect of low magnitude and significant at a Local level. Terrestrial invertebrate mortality resulting from construction activities would be of low magnitude and significant at a Local level. Aquatic invertebrates Area 3 was identified as supporting only one aquatic invertebrate of conservation interest. As this area is to be subject to permanent habitat loss as a result of the 1,800 MW scheme, the impact is considered to be of medium magnitude and significant at a Local level. The 1,800 MW scheme is considered to be unlikely to comprise a barrier effect to aquatic invertebrates and this potential impact was considered to be negligible and as such not significant. Disturbance to aquatic invertebrates during the construction activities may include visual, noise, dust and lighting. These potential impacts could result in a negative effect of low magnitude and significant at a Local level. Aquatic invertebrate mortality resulting from construction activities would be of low magnitude at a Local level.
Operation
Potential impacts to VERs as a result of the 1,800 MW CCGT- Potential impacts during operation are predicted to remain only scheme option include: as per the 1,800 MW CCGT-only scheme option. The • air quality effects resulting from operational emissions; stack heights will be determined through modelling to inform the final design to ensure no impact on sensitive • water discharge to Medway Estuary and Marshes SSSI/ receptors (including ecology), and will be at least 75 m SPA/ Ramsar site; high for the CCGT units and 50 m high for the OCGT • disturbance impacts resulting from noise and vibration and peaking plant. light associated with the operational processes of DHC2; The approved Landscape and Habitat Management Plan and (restoration plan)16 will be reviewed and updated, as • water pollution from surface water drainage from roads, necessary to reflect the revised layout. buildings and hardstanding areas. As discussed in Section 5.4, a Landscape Masterplan16 has been prepared and approved, which includes a habitat mitigation scheme to account for the proposed loss of existing habitat. This will be reviewed and updated, as necessary.
When lower critical load air quality figures are applied, the critical The heights and number of the stacks for the proposed loads are predicted to be exceeded for baseline conditions at the 1,800 MW CCGT with peaking plant scheme option will be majority of the designated sites and the 1,800 MW scheme is finalised in agreement with the EA and Natural England to considered to make an insignificant contribution to this. avoid significant effects on ecological receptors, in Operational air quality impacts on the Medway Estuary and particular the adjacent Medway Estuary and Marshes Marshes SSSI/SPA/Ramsar site and the associated interest SSSI/ SPA/ Ramsar site. Further detail is provided in features are considered negligible and therefore not significant. Section 6.2. The 2015 EIR concluded that the heights and number of the
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stacks for 1,800 MW CCGT-only scheme option would be finalised in agreement with the EA and Natural England to avoid significant effects on ecological receptors, in particular the adjacent Medway Estuary and Marshes SSSI/ SPA/ Ramsar site.
The increased levels of road traffic are considered to result in No increase to operational road traffic is anticipated for the locally increased levels of noise and vibration. Associated proposed 1,800 MW CCGT with peaking plant scheme disturbance impacts on flora and non-mobile fauna from the option compared to the previously assessed 1,800 MW operational power station are considered negligible. Whilst there CCGT-only scheme option. As such, the impact on is inconclusive evidence of the effects of noise and vibration on ecological receptors of noise and vibration generated by wildlife, it is considered that many of the species present are road traffic during the operational phase of the proposed likely to habituate to living in an active power station environment 1,800 MW CCGT with peaking plant scheme option is not and as such, the impact is not considered to be significant. considered to be significant.
Potential effects on bats during the operation of the 1,800 MW The level of lighting proposed for the 1,800 MW CCGT scheme are limited to disturbance principally through additional with peaking plant scheme option is not anticipated to lighting. The impact of lighting during the operational phase of differ significantly from those proposed for the 1,800 MW the 1,800 MW scheme is not considered to be significant. CCGT-only scheme option as it has the same development footprint. The effect of lighting during the operational phase of the proposed 1,800 MW CCGT with peaking plant scheme option is not considered to be significant.
Operational impacts on the Medway Estuary and Marshes SSSI/ Direct operational impacts to the Medway Estuary and SPA/ Ramsar site and the associated interest features are Marshes SSSI/ SPA/ Ramsar site and the associated considered negligible and therefore not significant. interest features are predicted to remain negligible and Potential effects to water bodies during the operation of the therefore not significant, based on the air impact 1,800 MW CCGT-only scheme option are predicated to be assessment presented in Section 5.2 and Appendix D and limited to the risk of pollution to waterbodies adjacent to Area 1. Appendix F. This may arise from surface water drainage from roads, There will be no significant change to water discharges to buildings and hard standing areas. the Medway Estuary (via Damhead Creek). Potential effects to water voles, amphibians and aquatic invertebrates during the operation of the 1,800 MW CCGT-only scheme option would be associated with water pollution which could result in harm to water voles and/or degradation to their habitat.
The potential impacts on VERs during the operational phase of No changes to the potential operation phase impacts on the 1,800 MW CCGT-only scheme option are considered to be VERs are envisaged as a result of the revised proposal. negligible and therefore not significant.
Cumulative Effects
The 2009 ES7 assessment considered the potential cumulative The decommissioning of Kingsnorth Power Station (Units effects of DHC2 in conjunction with the proposed supercritical 1-4) has been completed. However the programme for coal fired power station at Kingsnorth Units 5 and 6. Cumulative demolition is scheduled to continue to 2018, according to effects were not considered to be significant. information submitted in support of the Prior Notification for By the time of publication of the 2014 EIR8, the development of Proposed Demolition application submitted to Medway Kingsnorth Units 5 and 6 had been shelved and, as a result, no Council. It has therefore been taken into account in the cumulative effects with new projects in the area were predicted. assessment of cumulative effects. At the time of the 2015 EIR9 publication, the decommissioning of No changes to the potential cumulative effects are the existing Kingsnorth Power Station (Units 1-4) had envisaged as a result of the revised proposal. commenced. However no changes to the potential cumulative effects were envisaged.
Mitigation
Mitigation measures are proposed for all significant ecological The approved Landscape and Habitat Management Plan
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impacts on the habitats and species identified above. (restoration plan)16 will be reviewed and updated, as Generic mitigation measures include implementation of best necessary to reflect the revised layout, and the CEMP practice methods and adopting general principles that can be (approved by Medway Council on 23 December 2015 applied to DHC2 as a whole, and are relevant to all habitats and under planning reference MC/15/4047) will be will be species. Prevention or avoidance of adverse impacts is the reviewed and updated, as necessary for the development. primary aim of ecological mitigation. If this is not possible No additional mitigation measures are proposed. measures would be proposed to reduce the impact and if this is also not possible then measures to offset the impact would be included in the mitigation strategy. A substantial level of mitigation has previously been implemented across a wide area. A mitigation area was created subject to a Nature Conservation Management Plan in 1998. This required the establishment of a series of development and maintenance works over a five year period and which included botanical survey, translocation of important habitats, habitat creation, and subsequent monitoring. The mitigation works undertaken and the mitigation land put aside for the existing Damhead Creek CCGT Power Station were designed and agreed to offset and compensate for both the existing Damhead Creek CCGT Power Station and DHC2. It was considered that the mitigation land already in existence would go some way to offsetting impacts associated with DHC2. Generic mitigation would be in the form of the implementation of a CEMP by the appointed contractor and the development of a Works Method Statement to illustrate how impacts on ecology will be managed will be created. Specific mitigation of impacts to VERs comprising the Medway Estuary and Marshes SPA/ SSSI/ Ramsar, water bodies, badger, water vole, bats, birds, reptiles, amphibians, terrestrial and aquatic invertebrates are included. The conditions attached to the planning permission for change of use of environmental mitigation land associated with the existing Damhead Creek CCGT Power Station will ensure that mitigation measures identified in the 2009 ES will be undertaken and mitigation land will be set aside to compensate for and mitigate the ecological impacts. The 2015 EIR concluded that the approved Landscape and Habitat Management Plan (restoration plan)16 would be reviewed and updated, as necessary to reflect the revised layout of the 1,800 MW CCGT-only scheme option.
6.5.5 Conclusions The appraisal of ecological effects concludes that the 1,800 MW CCGT with peaking plant scheme option will not have any more significant effects on the designated site or any other ecological receptors to those predicted for the 1,800 MW CCGT-only scheme option. Mitigation measures will be implemented during design, construction and operation, including use of stack heights sufficient to avoid significant adverse air quality effects on designated sites, implementation or revision of the approved CEMP, use of appropriate noise mitigation and the agreed NMMP15, and implementation of an approved Landscape and Habitat Management Plan incorporating ecological enhancements. The approved Landscape and Habitat Management Plan (restoration plan)16 will be reviewed and updated as necessary to reflect the revised layout.
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6.6 Water Quality 6.6.1 Introduction This section considers the potential changes to effects on water quality during construction and operation likely to arise as a result of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the 1,800 MW CCGT-only scheme option. An updated Flood Risk Assessment (FRA) has been been undertaken to support this variation to the current Section 36 Consent for DHC2 and is provided in Appendix I. 6.6.2 Baseline Conditions The water quality assessment presented in Chapter 14 of the 2009 ES summarised the baseline conditions, in terms of watercourses, water bodies, water abstractions, discharges and quality. This section presents a summary of that baseline description, with updates where necessary (for example with reference to the Thames River Basin Management Plan which was published in October 201538); the baseline is assumed to be largely unchanged and therefore representative of the water environment at the time of publication of this report. The existing Damhead Creek CCGT Power Station is located on the Hoo Peninsula between the River Thames to the north and the River Medway to the south. The River Medway is the closer of these two rivers, passing approximately 1 km to the south of the application site (see Figure 1). The application site is separated from the Medway Estuary by the site of the former Kingsnorth Power Station.
Damhead Creek, which is located to the east of the application site, drains to the River Medway and forms part of the Medway Estuary and Marshes SSSI, SPA and Ramsar nature conservation site (see Section 6.5 above). The cooling water outfall from the former Kingsnorth Power Station fed into Damhead Creek, and small quantities of aqueous effluents that are produced from the existing Damhead Creek Power CCGT Station also flow into the Creek. As it flows east, the Damhead Creek becomes East Hoo Creek, which in turn flows into Kethold Reach, the main channel of the Medway Estuary.
Watercourses in the vicinity of the application site can be seen in Figure 1.
The Medway Estuary is a tidal saline water habitat subject to tidal fluctuations in level. Water drains from the salt flats such as Stoke Saltings during the ebb tide. The estuary experiences a wide range of temperatures with the solar heating of the tidal flats at low tide and the ingress of cooler water from the Thames Estuary at high tide.
The Thames River Basin Management Plan41 classifies the current and future objective status of watercourses and water bodies, and sets out measures for their improvement, to meet the requirements of the European Water Framework Directive. The aim is for all water bodies to achieve at least ‘Good’ or ‘Good potential’ status by 2015, or 2027 at the latest. Both Damhead Creek and the Medway Estuary in the vicinity of the application site are currently considered to have ‘Moderate’ overall status and the aim for both is to achieve ‘Good’ by 2027. 6.6.3 Differences Between Proposed Scheme Options The following differences between the proposed 1,800 MW CCGT with peaking plant scheme option and the already consented 1,800 CCGT-only scheme option have been considered as part of the water quality assessment:
• amendments to layout of plant and buildings;
• proportionately less steam cycle blowdown water demand. There will be no change compared to the 1,800 MW CCGT-only scheme option in terms of:
• source of water supply during construction and operation (town water or borehole);
38 Environment Agency (2015) River Basin Management Plan Thames River Basin District.
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• discharge of any effluents during construction, including site drainage (to be agreed by the contractor with the Environment Agency and Southern Water);
• surface water runoff, discharged from the drainage system, from impermeable surfacing over the development footprint;
• the quality of process effluent and boiler blowdown water to be discharged; and
• the proposed design of drainage systems (either using the existing DHC Power Station drainage system or an independent drainage system for DHC2). As described in the 2009 ES, 2014 EIR and 2015 EIR, the construction activities will be planned to minimise environmental risks as far as practicable, in accordance with a Construction Environmental Management Plan. 6.6.4 Appraisal of Environmental Impacts and Mitigation Table 6.6.1: Appraisal of Water Quality Effects
1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Construction
A small amount of water will be required each day for the The proposed 1,800 MW CCGT with peaking plant general construction works. scheme option may increase the duration of the Several construction activities could require the disposal of water construction period depending on the construction from the DHC2 site, such as washing facilities and run off from approach o be used, although the intensity of activities or hardstanding. Construction contractors would be required to the number of construction staff will remain comparable. reach agreement with the Environment Agency and, if The water demand is therefore not expected to necessary, the local sewerage undertakers, with regard to the significantly increase and agreements and/or licences for detailed methods of disposal. The conditions for any discharge the discharge of surface water will be made with the to the sewer will be set out in a separate trade effluent discharge Environment Agency and/or Southern Water with licence. appropriate conditions to prevent pollution and avoid The 2015 EIR9 noted that the intensity of activities and the increasing flood risk on or off site. number of construction staff on site at the peak of construction No difference is expected in terms of water quality impacts was likely to be greater for the 1,800 MW CCGT-only scheme arising from the construction phase if the 1,800 MW CCGT option than for the previously assessed option. However water with peaking plant option is selected compared to the demand was not expected to increase significantly and consented 1,800 MW CCGT-only scheme option. agreements and/or licences for the discharge of surface water would be made with the Environment Agency and/or Southern Water with appropriate conditions to prevent pollution and avoid increasing flood risk on or off site.
Operation
During normal operation of DHC2 water will be required on a The total quantity of water required is not expected to day-to-day basis for make-up to the boiler water system. increase and no changes in potential effect on water Together with the miscellaneous minor process requirement of quality as a result. 5 m3 per day approximately, the total quantity of water from Damhead Creek's supply required by the 1,800 MW CCGT-only scheme option would be of the order of approximately 750 m3 per day.
Effluent discharge - The quality of the effluent will be The quality of effluent will not change. monitored, including the following parameters: flow, pH, The quantity of effluent is not expected to increaseand it is suspended solids, oils and grease. not considered to alter the likely effect on water quality due These discharges will be controlled to the limits set by the to the controls that will be implemented through the Environment Agency in the DHC2 Environmental Permit. The Environmental Permit. conditions for any discharge to the sewer will be set out in a separate trade effluent discharge licence. The surface water from any areas of the DHC2 site that are likely
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to be contaminated with oil will drain to oil interceptor(s) to limit the oil in water content to a level regulated by the DHC2 Environmental Permit, before discharge to the storm water drainage system. The 2015 EIR9 noted that the quantity of effluent would increase proportionately for the 1,800 MW CCGT-only scheme option. But concluded that the increase was not considered to alter the likely effect on water quality due to the controls that will be implemented through the Environmental Permit.
Boiler water - The boiler water/ steam/ condensate system will The quality of blowdown water will not change. have losses from its recycled water due to some deliberate The quantity of blowdown water to be discharged will blowdown from the boilers to maintain the correct chemical decrease proportionately. However this is not considered control. The majority of this boiler blowdown will be reused by to alter the likely effect on water quality due to the controls recycling through the water treatment plant. It will comprise that will be implemented through the Environmental virtually pure water containing very small quantities of various Permit. corrosion and scaling prevention chemicals in the boilers (for example, ammonia, phosphate and suspended solids). Any blowdown water to be discharged will be treated for pH prior to release to the surface water drainage system. The 2015 EIR noted that the quantity of the blowdown water to be discharged as part of the 1,800 MW CCGT-only scheme option would increase proportionately compared to the previously consented scheme, but that the increase would not alter the likely effect on water quality due to the Environmental Permit controls.
The water treatment plant - Demineralised water is anticipated No change is expected for the 1,800 MW CCGT with to be produced by a new water treatment plant for DHC2. The peaking plant scheme option. effluent from this plant would be discharged to the site drainage system in such small quantities that it will have no significant environmental effect. Discharges will be controlled through the Environmental Permit.
Site drainage - There are four drainage systems on the existing An outline drainage strategy is included in the FRA at Damhead Creek CCGT Power Station site; the surface water Appendix I, and is in line with previous agreements drainage system; the oily water drainage system; the reached regarding drainage. The quality and quantity of contaminated waste water system (i.e. water treatment plant water to be discharged by the drainage system will not effluent and boiler blow down); and the onsite sewerage system. change. The final design of the drainage system will Two drainage options have been identified for DHC2 in the ensure appropriate treatment and attenuation for this Drainage Scheme Report submitted to Medway Council in larger volume to discharge rates agreed with the December 2012. Option 1 would utilise the existing DHC1 Environment Agency. No changes to the effects on water drainage infrastructure, including the stormwater basin, and quality or flood risk on or off site are anticipated. Option 2 would comprise an independent drainage system. Both Discharges to Damhead Creek will be controlled in options discharge uncontaminated water to Damhead Creek, accordance with the Environmental Permit. following appropriate treatment and attenuation, and sewage to the existing sewerage network. The final drainage option will be developed in accordance with the final design for the power plant and submitted to the Environment Agency. All elements of the treatment systems would be regularly monitored to ensure optimum performance and maintenance. The 2015 EIR9 identified that the 1,800 MW CCGT-only scheme option would produce proportionately larger volumes of water to be discharged. The final design of the drainage system would ensure appropriate treatment and attenuation to discharge rates agreed with the Environment Agency. Discharges to Damhead
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Creek would be controlled in accordance with the Environmental Permit. The 2015 EIR concluded that no changes to the effects on water quality or flood risk on or off site were anticipated.
Miscellaneous discharges - From time to time (likely to be The types, volumes and methods for disposing of the about two times a year) it will be necessary to wash the blades miscellaneous discharges described for the 1,800 MW of the air compressor section of the gas turbines to remove CCGT-only scheme option will not be significantly altered debris that has penetrated the inlet air filters and become lodged for the 1,800 MW CCGT with peaking plant scheme on the compressor blades. Waste water containing detergent will option, and as such there is no change to the predicted be retained on-site in a storage tank and subsequently tankered effects on water quality. off-site by a licensed contractor for disposal at an appropriately licensed disposal facility. Boiler flue gas side washing is not anticipated. However, during commissioning and at infrequent intervals during the life of DHC2 it will be necessary to chemically clean the water side of the boiler tubes. All effluents will be tankered off site by a licensed contractor for treatment and disposal at an appropriately licensed disposal facility. During maintenance it may be necessary to drain down the boiler, the closed circuit cooling water system or parts of these systems. All will be discharged to the site drainage system. The boiler water discharged will be identical to boiler blowdown and will be high purity water containing traces of ammonia, phosphate and suspended solids. The closed circuit cooling water will be high purity water containing small amounts of corrosion inhibitor (probably hydrazine or nitrite/borate). During the detailed engineering stage, consideration will be given to the storage, recovery and reuse of these effluents to further minimise the impact of the plant. Sample points will be provided on the outlet of the oil separators, and in any drains at the DHC2 site prior to discharge. No prescribed substances as described in the Environmental Permitting (England and Wales) Regulations 200720 will be generated or used on the DHC2 site.
Cumulative Effects
The 2009 ES7 assessment considered the potential cumulative The decommissioning of Kingsnorth Power Station (Units effects on water quality of DHC2 in conjunction with the 1-4) has been completed. However the programme for proposed supercritical coal fired power station at Kingsnorth demolition is scheduled to continue to 2018, according to Units 5 and 6 and the proposed Kingsnorth Business Park. information submitted in support of the Prior Notification for Cumulative effects were not considered to be significant. Proposed Demolition application submitted to Medway At the time of publication of the 2014 EIR8, Kingsnorth Units 5 Council. It has therefore been taken into account in the and 6 had been shelved and, as a result, no cumulative effects assessment of cumulative effects. with this project were possible. No changes to the potential cumulative effects are The principal cumulative impact with the proposed Kingsnorth envisaged. Business Park development would be associated with surface water run off. However, as both DHC2 and the Kingsnorth Business Park will incorporate storm water drainage systems that include balancing ponds, the impact on water quality would be negligible. At the time of the 2015 EIR9 publication, the decommissioning of the existing Kingsnorth Power Station (Units 1-4) had commenced. However no changes to the potential cumulative effects were envisaged.
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Mitigation
Construction All measures proposed for the 1,800 MW CCGT-only The British Standard Code of Practice for Earthworks (BS scheme option would be applied and implemented through 6031:2009) 39 contains detailed methods that will be considered an updated CEMP no matter which option is progressed. for the general control of drainage on construction sites. Further No additional construction mitigation is required for the advice is also available in Eurocode 7: Geotechnical Design40. proposed 1,800 MW CCGT with peaking plant scheme These will be taken into account in the detailed design and option. construction of DHC2. Mitigation measures during construction will include those listed below, as appropriate. • Any oil storage tanks to be located on an impervious base provided with bund walls to give a containment capacity of at least 110% of the tank volume. All valves and couplings to be contained within the bunded area. • Any surface water contaminated by hydrocarbons, which are used during the construction phase, to be passed through oil/ grit interceptor(s) prior to discharge. • Measures will be taken to ensure that no leachate or any surface water that has the potential to be contaminated is allowed to enter directly or indirectly into any water course, underground strata or adjoining land. These will include concrete gullies, dewatering ponds and other similar measures. • Provisions will be made so that all existing drainage systems continue to operate. These will include regular visual inspections and corrective measures as appropriate. • Water inflows to excavated areas will be minimised by the use of lining materials, good housekeeping techniques and by the control of drainage and construction materials in order to prevent the contamination of ground water. Site personnel will be made aware of the potential impact on ground and surface water associated with certain aspects of the construction works to further reduce the incidence of accidental impacts. • Refuelling of construction vehicles and equipment will be restricted to a designated area with properly designed fuel tanks and bunds and proper operating procedures. The conditions attached to the Section 90 Direction and the approved Drainage Scheme Report will be adhered to, including the preparation of a Construction Environmental Management Plan (CEMP).
Operation Two drainage options were identified in the Drainage The Environment Agency will set limits on the quality and Scheme Report submitted to Medway Council in quantity of water that is discharged from the DHC2 site under the December 2012. An outline drainage strategy is included DHC2 Environmental Permit. Southern Water will be consulted in the FRA at Appendix I, and is in line with the options concerning any discharge to the sewer, as this will require a previously identified and consulted upon with Medway separate Trade Effluent Discharge Licence. Council. The final drainage design for the proposed 1,800 MW CCGT with peaking plant scheme option will be All aqueous process effluents will be discharged to the Damhead developed in accordance with relevant guidance to prevent
39 British Standards Institution (2009) BS 6031: Code of practice for earthworks. 40 British Standards Institution (2007) BS EN 1997-2 Eurocode 7: Geotechnical Design – Ground investigation and testing.
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Creek via either the existing drainage system at Damhead Creek pollution and provide appropriate attenuation on site to CCGT Power Station or a new independent drainage system for avoid increasing flood risk on or off site, and approved by DHC2. The drainage system will incorporate oil interceptors but the Environment Agency and Medway Council. no further on-site treatment will be necessary as the process At present no connection to the sewer is anticipated to be effluent is effectively pure water. This represents the best required as an on-site sewage treatment plant will be practicable environmental option for these effluents. provided, which would discharge to the storm water basin. The water treatment plant effluent will be monitored for pH value. The Flood Risk Assessment (FRA) prepared in 2009 has If the pH is out-with the limit of 6 to 9, or outside any limit now been updated (Appendix I) to for the proposed 1,800 permitted by the Environment Agency, the discharge will MW CCGT with peaking plant scheme option. automatically stop until the failure is corrected. The use of de-icing substances will be minimised during the winter. All oil and chemical storage tanks and areas where drums are stored will be surrounded by an impermeable bund. Single tanks will be within bunds sized to contain 110% of capacity and multiple tanks or drums will be within bunds sized to contain 110% of the capacity of the largest tank. Permanently fixed taps, filler pipes, pumping equipment, vents and sight glasses will also be located within the bunded area. Taps and valves will be designed to discharge downwards and will be shut and locked in that position. Manually started electrically operated pumps will remove surface water collected within the bund and its composition will be verified through appropriate analysis prior to disposal. The surface water drainage system will drain areas of the DHC2 site unlikely to be contaminated with oil due to their location and discharge the water to a storm water drainage system. The majority of the surface water drainage will be uncontaminated and typical of surface water run-off from paved areas or roads. The potential for contamination will be minimal and associated with areas around storage vessels, which will be appropriately bunded. An oily waste water drainage system will drain all areas where oil spillages could occur. The design will incorporate oil interceptors and traps. These will discharge with the other surface water discharge to a storm water discharge system. The discharge from each oil interceptor will contain no visible oil or grease. Adequate facilities for the inspection and maintenance of oil interceptors will be provided and the interceptors will be emptied as necessary and de-sludged to ensure efficient operation. A qualified contractor will dispose of the sludge off-site. All elements of the treatment systems will be regularly monitored to ensure optimum performance and maintenance. DHC2 will be designed to take into account the flood risks associated with the DHC2 site. These were outlined in the Flood Risk Assessment prepared for DHC2 (see Appendix H of the 2009 ES7). Mitigation measures incorporated into the design of the DHC2 site will include the bunding / elevation of equipment that could cause contamination to water and all equipment at the DHC2 site sensitive to water exposure. The 2015 EIR9 identified that the final drainage design for the 1,800 MW CCGT-only scheme option would be developed in accordance with relevant guidance to prevent pollution and provide appropriate attenuation on site to avoid increasing flood risk on or off site, and approved by the Environment Agency and
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Medway Council. The 2015 EIR also noted that no connection to the sewer was required as an on-site sewage treatment plant would be provided, which would discharge to the storm water basin.
6.6.5 Conclusions The quantity and quality of liquid discharges during construction and operation of the proposed 1,800 MW CCGT with peaking plant scheme option will be similar to the 1,800 MW CCGT-only scheme option. The discharge of surface water will be consented through the Environmental Permit and/or through appropriate licencing by Southern Water with appropriate conditions to prevent pollution and avoid increasing flood risk on or off site.
Two drainage options have been identified for DHC2 in the Drainage Scheme Report submitted to Medway Council in December 2012. Both options ultimately discharge uncontaminated surface water to Damhead Creek, following appropriate treatment and attenuation, and sewage to the existing sewerage network. The updated FRA includes an outline drainage strategy, which is in line with the options previously identified and consulted upon. The final drainage option will be developed in accordance with the final design for the power plant and submitted to the Environment Agency. The area of impermeable surfacing will remain the same, and by maintaining the same attenuation rates as committed to in the Drainage Scheme Report, the flood risk will not be increased as a result of the proposed changes. This may necessitate additional stormwater attenuation on site which would be designed into the final design proposal for the development. Mitigation measures will be implemented to minimise the risk of accidental pollution including the CEMP, Environmental Permit obligations, appropriate bunding of oil and chemical storage tanks and use of oil interceptors where necessary in the drainage system.
In conclusion, no significant effects are predicted for the proposed 1,800 MW CCGT with peaking plant scheme option, as was the case for the currently consented compared to the 1,800 MW CCGT-only scheme option.
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6.7 Geology, Hydrology and Land Contamination 6.7.1 Introduction This section considers the potential changes to effects on geology, hydrology and land quality during construction and operation as a result of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the 1,800 MW CCGT-only scheme option. A Flood Risk Assessment (FRA) has been been undertaken to support this variation to the current Section 36 Consent for DHC2 and is provided in Appendix I. 6.7.2 Baseline Conditions The geology, hydrology and land contamination assessment chapter presented in Chapter 15 of the 2009 ES summarised the baseline conditions, in terms of historic land use and potential for contamination sources, geology and soils, hydrogeology, hydrology and flood risk (ScottishPower, 2009). This section presents a summary of that baseline description, updated as necessary using additional information gathering from subsequent work at the site.
Information on the baseline conditions at the application site has been obtained through a review of historical maps, as well as Phase 1 Desk Based Studies relating to Areas 1-3 (DTS Raeburn, 200641 and Parsons Brinckerhoff, 200842) and Phase 2 Intrusive Site Investigations relating to Areas 1-3 (Terra Tek Ltd., 200743 and Parsons Brinckerhoff, 2009a44). These reports were included in the 2009 ES7 Volume 2, Appendix I. Since the 2009 ES was prepared, Parsons Brinkerhoff has undertaken monitoring of groundwater and ground gas at the site in 201145 and additional investigation of hydrocarbons in Area 3 in 201246, RSK conducted additional site investigation in Area 1 in 201247, and an updated Envirocheck report for the Area 1 was obtained in 2014 to inform the ongoing Site Condition Report that is being prepared to support the DHC2 Environmental Permit application.
The locations of Areas 1-3 within the application site boundary are provided on Figure 2.
History of Land Use on the Application Site Historical maps from 1870 to present day (provided within the Phase 1 and Phase 2 reports referred to above) have been reviewed to identify the historical land use of the application site and surrounds and understand the potential sources of historic contamination.
Maps from 1870 to 1900 show the application site was divided into fields, possibly separated by surface water features. The north-eastern part of the site comprises several watercourses. By 1971, all watercourses had been removed. Maps from 1971 also show the development of the existing Kingsnorth Coal Fired Power Station approximately 500 m to the south and an oil refinery (known as Kingsnorth Oil Refinery) adjacent to the north-west of the application site. Part of the Kingsnorth Oil Refinery, namely three large tanks, is shown to be located within the north-east part of the application site (Area 2) on mapping dated 1970. The oil refinery was removed in the 1990s and replaced with a variety of works (now known as Kingsnorth Industrial Estate). The existing Damhead Creek CCGT Power Station is first shown on mapping published in 2003.
Fuel/ product storage tanks were present within the north-eastern part of the application site (Area 2) as early as 1914, and by 1966 bulk storage tanks associated with the adjacent oil refinery were present across the rest of Area 2. The tanks were reportedly demolished following the decommissioning of the Kingsnorth Oil Refinery during the 1990s.
41 DTS Raeburn Ltd. (2006) Phase 1 Desk Study. 42 Parsons Brinckerhoff Ltd. (2008) Phase 1 Desk Study. 43 Terra Tek Ltd. (2007) Phase 2 Intrusive Site Investigation. 44 Parsons Brinckerhoff Ltd. (2009) Phase 2 Intrusive Site Investigation. 45 Parsons Brinckerhoff Ltd (2011) Gas and Ground Water Monitoring Summary Report for Units 2B and 3 46 Parsons Brinckerhoff Ltd (2012) Damhead Creek Power Station Plot 3 Investigation 47 RSK (2012) Ground Investigation and remediation Damhead Creek 2 Power Station
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Area 3 has remained totally undeveloped throughout the past, although it was in-filled with dredging materials, pulverised fuel ash (PFA) and other inert wastes in the 1960s. Around this time, several ponds were also constructed on the site to suppress dust from the dumping of PFA.
Archaeological records indicate that between 1870 and the present day, the application site was part of a naval airship installation operated by the Royal Naval Air Service (RNAS Kingsnorth) which occupied the site between 1912 and 1920 (see Section 6.9). Figures indicate that the majority of the airship base was located to the west and north-west of the application site and included airship hangars, a large hydrogen gas generating station with several gasholders, a depot for gas cylinders and numerous workshops, machine rooms and stores. The main potential sources of contamination on the application site are considered to be from off-site sources, since the site has accommodated limited development in the past. Potential off-site sources of contamination include the former gasholders and gasworks associated with the former RNAS Kingsnorth airship base, the now demolished Kingsnorth Power Station, which was located approximately 500 m south of the application site, the existing Damhead Creek CCGT Power Station, adjacent to the eastern boundary of the application site and the former Kingsnorth Oil Refinery, previously located approximately 100 m north-east of the application site. Due to the type of industry involved, the most likely forms of contamination from these off-site sources are considered to be total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAH) and acids.
Potential on-site sources of contamination at Area 3 are from PFA, inert wastes and sediments, which were used for infilling the land in the 1960s. Potential on-site sources of contamination at Area 2 are considered to be hydrocarbons (PAH, TPH) from fuel tanks. The only potential on-site sources of contamination identified at Area 1 are temporary storage of soils in the western part of Area 1 and PFA in the central part of Area 1.
The Environment Agency’s ‘What’s in your Backyard?’ website48 shows that the north-east part of the site (Area 3) is a former landfill. The landfill site, which was operated by British Oil and Minerals, is known as ‘Kingsnorth’ and is reported to have received waste between December 1978 and December 1990. The Environment Agency indicates that the buried waste is inert49.
Three further historic landfill sites are recorded in the vicinity of the application site, the nearest being adjacent to the north of the application site boundary and known as ‘Kingsnorth Area’. ‘Kingsnorth Industrial Estate’ historic landfill, operated by Kingsnorth Industrial Estate (licence number 19402), is located approximately 320 m north-east of the application site and ‘Kingsnorth Power Station’ historic landfill, operated by Central Electricity Generating Board, is located approximately 170 m south of the application site. The latter was in operation between December 1964 and December 1990. The Environment Agency indicates that the buried waste in these surrounding sites is inert.
Although none of the above landfills remain active, there is still the potential for off-site migration of leachate or ground gas from buried waste to the application site.
Geology and Soils Review of British Geological Survey (BGS) 1:50 000 scale solid and drift Geology map (Sheet 272; Chatham50) and BGS online maps51 indicates that superficial deposits at the application site and much of the surrounding area comprise marine and estuarine alluvium, Head Brickearth, and River Terrace Gravels (west and north of the application site). Typically drift deposits range in thickness between 5 to 10 m.
The underlying solid bedrock geology consists of London Clay overlying Lambeth Group interbedded sand and clays (formerly Woolwich and Reading beds), Thanet Sand Formation, and Cretaceous Chalk.
48 Environment Agency (2013) What’s in Your Backyard? Available from: http://www.environment- agency.gov.uk/homeandleisure/37793.aspx 49 Waste which remains largely unaltered once buried such as glass, concrete, bricks, tiles, soil and stones. 50 British Geological Survey (BGS) (1977) British Geological Survey mapping: Sheet 272, Chatham. 51 British Geological Survey (BGS) (dna) GeoIndex available from http://www.bgs.ac.uk/geoindex/ [accessed 30th April 2015].
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In addition to the above deposits, Made Ground was encountered at various locations across the application site. Further details on the geology encountered are available in the site investigation reports.
The surrounding areas of Kingsnorth and Hoo St. Werburgh are of a varying land quality, as shown by DEFRA Agricultural Land Classification (ALC) maps52. The sites are classified as ‘urban’ in character, and as such there are no areas of fertile soil or high quality agricultural land in the immediate vicinity of the application site. However, approximately 500 m north of the application site, is a large area (approximately 355,000 ha) of high quality agricultural land (Grade 1).
Hydrogeology The marine and estuarine alluvium deposits, head brickearth and river terrace deposits underlying the application site are described as a Secondary Undifferentiated Aquifer. A Secondary Undifferentiated Aquifer is assigned where it is not possible to attribute either category Secondary-A or Secondary-B to a rock type. Secondary-A aquifers are permeable layers capable of supporting water supplies at a local rather than strategic scale, and in some cases forming an important source of base flow to rivers. Secondary-B aquifers are predominantly lower permeability layers which may store and yield limited amounts of groundwater due to localised features such as fissures, thin permeable horizons and weathering.
London Clay, which underlies the superficial deposits, is classified as unproductive strata, which are defined as rock layers or drift deposits with low permeability that have negligible significance for water supply or river base flow.
The Thanet Sand Formation and Upper Chalk strata, which occur at depth beneath the Lambeth Group, are classified as a Principal Aquifer. Principal Aquifers are defined as layers of rock or drift deposits that have inter-granular and/or fracture permeability and can often provide a high level of water storage. They may support water supply and/or river base flow in a strategic scale. However, the Thanet Sands and Chalk deposits are overlain by a significant depth of London Clay and are not considered to be at risk from percolation of any pollutants which may potentially occur as a result of any development on the application site.
Groundwater flow may take place and needs to be taken into account when assessing the risk associated with persistent pollutants occurring as a result of DHC2.
There are no Nitrate Vulnerable Zones (NVZ) or Nitrate Sensitive Areas (NSA) within 1 km of the application site and the application site does not lie within a Source Protection Zone (SPZ).
The Phase 1 and Phase 2 investigations found there to be relatively shallow groundwater levels across the application site, which are likely to be due to the close proximity of the application site to Damhead Creek, and as such, perched groundwater beneath the site is most likely in hydraulic continuity with Damhead Creek.
Groundwater and surface water samples were collected during previous investigations at the site and these are discussed in more detail in each of the SI reports.
Hydrology Historical maps (from 1897) have suggested that there were a number of ditches dissecting the application site into fields. However, by 1971 these appear on the map as much smaller field boundaries, suggesting that the ditches were in-filled or removed. By 1999, no evidence of the field boundaries remained. Damhead Creek is located approximately 100 m south-east of the application site at its closest point. It is a tributary of the tidal River Medway and flows from the eastern boundary of the existing Kingsnorth Power Station, past the southern boundary of the application site and the existing Damhead Creek CCGT Power Station before turning north-east and then south-east and entering the River Medway.
52 Department for Food, the Environment and Rural Affairs (DEFRA) (dna(a)) MAGIC website: http://www.magic.gov.uk/home.htm [accessed 5th May 2015]
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The River Medway is located approximately 1 km to the south of the application site at its closest point. It is also tidal at this point and approximately 1 km wide. The Medway Estuary is a tidal saline water subject to tidal fluctuations in level. Water drains from the salt flats such as Stoke Saltings during the ebb tide. The estuary experiences a wide range of temperatures with the solar heating of the tidal flats at low tide and the ingress of cooler water from the Thames Estuary at high tide. Damhead Creek and the Medway Estuary have been assessed as part of the Water Framework Directive (WFD) (Environment Agency, 2009) Damhead Creek and the Medway adjacent to the site lie within the Medway estuarine water body (Ref GB530604002300), part of the Thames River Basin Management Plan41. Currently the water body is recorded as having an overall rating of “at risk”. The water body is recorded as “mixed, macro, extensive intertidal” that has been heavily modified. The current ecological quality is recorded as being of moderate potential, with the current chemical quality of fail, though predicted to improve to good in 2015. As part of the WFD, the River Medway has been classified as a ‘transitional waterway’ (transitional environment between the land and the sea and from fresh to saline water) and was deemed ‘at risk’ from point and diffuse source pollution, and ‘probably at risk’ from water abstraction and flow regulation, physical or morphological alteration and introduction of alien species.
Flood Risk An updated FRA has been undertaken, and is included as Appendix I.
The Environment Agency Flood Map53 shows Areas 1 and 2 as being located in Flood Zone 3 benefiting from flood defences, and Area 2 as being within Flood Zone 2. Flood Zone 3 comprises land assessed as having a 1 in 100 year or greater (>1%) annual probability of river flooding or a 1 in 200 year or greater (0.5%) annual probability of flooding from the sea. Flood Zone 2 comprises land assessed as having a 1 in 1,000 year (0.1%) annual probability of flooding from river or sea.
The site is protected by primary flood defences along the north bank of the River Medway (maintained by the Environment Agency), to the south and east of the application site and secondary earth bunds, with a crest elevation of approximately 5.6 m AOD. These bunds provide further protection from tidal inundation to a standard of between a 0.5% and 0.1% AEP flood event. In addition, a substantial area to the north and east of the site (proposed for the development of the carbon capture and storage/laydown area) is situated above 5.3 m AOD due to large quantities of PFA deposited on the site from its former use as a landfill. Therefore much of this site area is not considered at risk from flooding during a 0.1% AEP flood event. Tidal flooding represents the most significant risk to the Site but the risk of tidal flooding is considered to be low as the Site is protected to the 0.1% AEP indicative standard.
As the Site is afforded protection from defences up to the 0.1% AEP flood event, the primary risk from tidal sources is the residual risk from overtopping and/or failure of the defences. ScottishPower has future general maintenance plans to improve the existing flood defence to the south-west of the DHC1 site. Other than the Medway Estuary and some local ditches, there are no adjacent or nearby rivers and thus, the application site is not at risk from fluvial flooding of inland watercourses. The application site is considered to be at very low risk of from overland flooding from adjacent sites, and the Environment Agency has confirmed that no further flood defence improvements are required.
The undefended modelled flood water levels for the River Medway for the floodplain grid cells relevant to the Site for the 0.5% (1 in 200) AEP event are detailed within the updated FRA (Appendix I), and provide an indication as to the extent of flooding at the Site in the unlikely event that both primary and secondary defences were to fail. Ground levels in these areas of the Site are approximately 3.8 – 4.0 m AOD therefore the depth of flooding would be approximately 0.92 m. Area 3 remains unaffected as ground levels are above the modelled flood water levels for this event. The drainage system will be designed to avoid increasing flood risk on or off site (as well as preventing pollution), including appropriate storage and attenuation of surface water runoff to limit the rate of discharge to Damhead Creek. Where possible, swale ditches and other sustainable urban drainage system (SUDS) drainage techniques will be incorporated into the drainage design.
53 Environment Agency (2013) What’s in Your Backyard? Available from: http://www.environment- agency.gov.uk/homeandleisure/37793.aspx
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Due to the nature of the underlying geology (river terrace deposits classified as a minor aquifer) together with the higher elevation of the application site compared with surrounding land it should not be prone to groundwater flooding. Nor has flooding of this nature been recorded at the existing Damhead Creek CCGT Power Station in the past. The Environment Agency’s flood warning procedure and emergency evacuation procedure that are already in place for the existing Damhead Creek CCGT Power Station will also apply to DHC2.
Receptors Key environmental receptors for potential contamination originating from the application site include the following:
• construction workers;
• future site users (operational staff at Damhead Creek 2);
• groundwater and surface water; and
• in-ground structures.
The main sensitive ecological receptor in the vicinity of the Damhead Creek 2 site is considered to be the Medway Estuary and Marshes SSSI, SPA and Ramsar site, which is located approximately 100 m to the south-east of the application site at its closest point. 6.7.3 Differences Between Proposed Scheme Options There is no difference in the land take requirement and intrusive works across for the proposed 1,800MW CCGT with peaking plant scheme option compared to the 1,800 MW CCGT-only scheme option. 6.7.4 Appraisal of Environmental Impacts and Mitigation Table 6.7.1: Appraisal of Geology, Hydrology and Land Contamination Effects
1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Construction
Human Health Human Health There is the possibility that site workers could come into contact The measures previously proposed regarding asbestos with low levels of contamination in soils or groundwater and to protect workers during construction will remain (particularly from elevated levels of boron). Site investigations applicable and there will not any significant change to the undertaken following the Section 90 Direction do not reveal any impact on human health. additional requirements for remedial action for the prevention of No changes to the potential construction phase impacts on risks to human health based on screening against generic human health are envisaged as a result of the alternative assessment criteria derived in accordance with best practice at proposal to include peaking plant. the time. (It is noted that recent changes in guidance, with the introduction of S4ULs and C4SLs, will require the assessment conclusions to be reviewed.). An assessment of site soils against appropriate commercial assessment criteria has also confirmed that the site soils pose no significant risk to future site users through direct contact or inhalation of site dust. Petroleum hydrocarbons (diesel and oil) and tetrachloroethene were found to be present in groundwater at some locations beneath the DHC2 site in low concentrations and are likely to be attributable to an off-site source resulting from the surrounding land uses. A controlled waters risk assessment has shown that identified concentrations of these compounds in alluvium beneath the site will not impact DHC2 land.
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The 2015 EIR9 also noted that should asbestos be identified in made ground during future earthworks, the site could come under the Control of Asbestos Regulations 2012. Suitable mitigation measures should be adopted to minimise the risks to workers and the general public and minimise the potential spread of asbestos fibres. Such measures could include standard PPE and dust suppression measures, as well as potential fibre monitoring during the construction activities.
Underlying Geology Underlying Geology
The construction of the 1,800 MW CCGT-only scheme option The construction would result in the permanent loss of up would result in the permanent loss of approximately 19.8ha (full to 19.8 Ha (full land development) from a total site area of land development) of made ground / alluvium / river terrace 23.8 ha of made ground/ alluvium/ river terrace deposits. deposits, which has been set aside as an area for future The construction of the proposed 1,800 MW CCGT with development under the Medway Local Plan54. peaking plant scheme option will not result in any changes There would be no impact on the underlying chalk aquifer due to to the magnitude of impacts on underlying geology. the thickness of London Clay deposits underlying the site. There No changes to the potential construction phase impacts on are no geologically designated sites or fertile soils within the underlying geology are envisaged. immediate vicinity of the DHC2 site. Therefore, the impacts on the surrounding soils, geology and geomorphology are not expected to be significant. The impacts on soils and geology are not considered to be significant, as any impacts would be mainly confined to made ground and river deposits just below the subsurface. If any impacts did occur, they would be confined to localised, temporary erosion and compaction impacts caused by earthworks and vehicular movements. Impacts on near-surface soils would be within the construction footprint, laydown areas and access roads.
Surface and groundwater The proposed development will comply with the National 55 During the construction period, the disturbance of made ground Planning Policy for Waste (DCLG, 2014), relevant would enable greater percolation of rainfall across the DHC2 site Environment Agency guidance and The Control of 19 and may enable the mobilisation of low levels of contaminants. Pollution (Oil Storage) (England) Regulations 2001 . However, due to the very small amounts of contamination The construction of the proposed 1,800 MW CCGT with present within the made ground and the presence of the peaking plant scheme option will not result in any changes attenuating alluvial deposits underlying the made ground, the to the magnitude of impacts on surface and groundwater. impact of this was not considered to be significant as it was No changes to the potential construction phase impacts on anticipated that there would be very little leaching of any surface and groundwater are envisaged as a result of the contaminants to surface water or groundwater. alternative proposal to include peaking plant. Precipitation draining across exposed areas of the DHC2 site could result in sediment within surface run-off because of ground disturbance. However, the impact of this is considered to be minor providing excavations are sheeted during heavy rainfall events. The upper chalk underlying the DHC2 site at significant depth is considered a major aquifer. However, due to the significant depth of overlying London Clay (non- aquifer) the impact of the proposed works on the chalk aquifer is not considered to be significant. There is the potential for spills / leakage of oil associated with construction machinery and vehicles. The storage of fuel,
54 Medway Council (2003) Medway Local Plan. 55 Department for Communities and Local Government (DCLG) (2014) National Planning Policy for Waste.
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equipment and construction materials will be designed so as to minimise the risk of soil contamination or water pollution, for example through the use of bunds, drip trays and oil interceptors in accordance with Environment Agency guidelines, National Planning Policy on Waste and The Control of Pollution (Oil Storage) (England) Regulations 200119. The 2015 EIR9 noted that since the publication of the 2009 ES7 and the EIR, PPG10 has been replaced by the National Planning Policy for Waste57 and, as such, would be paid due regard in addition to relevant Environment Agency guidance and The Control of Pollution (Oil Storage) (England) Regulations 2001. It concluded that no changes to the potential construction phase impacts were envisaged.
Operation
The DHC2 site would be predominantly covered with buildings or No changes to the potential operational phase impacts on areas of hardstanding. A small area of the site would be geology, hydrology and contamination are envisaged as a landscaped but no areas of exposed (unvegetated) soils will be result of the revised proposal. present. As a result the potential pathway between any ground The undefended modelled flood water levels relevant to contaminants and site users would be broken. It was therefore the Site for the 0.5% (1 in 200) AEP event provides an considered that the potential for direct (dermal, oral or inhalation) indication as to the extent of flooding at the Site in the contact with any remaining contaminants present beneath the unlikely event that both primary and secondary defences surface was not significant for future site operatives. were to fail. Ground levels in these areas of the Site are All areas of the DHC2 site would drain to either a sewer or approximately 3.8 – 4.0 m AOD therefore the depth of Damhead Creek via a drainage system incorporating oil flooding would be approximately 0.92 m. Area 3 remains interceptors and silt traps. This would significantly reduce the unaffected as ground levels are above the modelled flood potential for percolation of pollutants, into groundwater or water levels for this event. surface water following rainfall. The impact was therefore The same mitigation measures will be adopted and considered not significant. regulated by the EA through the Environmental Permit no Only relatively small quantities of potentially hazardous matter which of the CCGT-only or the CCGT with peaking substances would be stored and used at the DHC2 site. These plant option is progressed. substances would include transformer and lubricating oils as well In addtition a conceptual surface water drainage strategy as de-scaling chemicals used in the boiler. All oils and chemicals is included within the FRA (Appendix I) to support the would be stored in appropriate bunds and / or storage areas in planning application and should incorporate suitable accordance with all relevant guidance and legislation as detailed SUDS. above. A Drainage Scheme Report has been approved by the Council and is designed to ensure the prevention of contamination of watercourses and that appropriate drainage and proper containment facilities are provided.
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Mitigation Measures
Construction Construction
During construction, all spoil would be stockpiled away from The same mitigation measures will be adopted, including surface water and freshly excavated areas. A minimum distance implementation of an updated Construction Environmental of stockpiles from surface water would be agreed with the Management Plan (CEMP). Environment Agency and construction contractors. Data from The proposed development will comply with the National Phase 2 Intrusive Site Investigations suggests that the site is not Planning Policy for Waste57, relevant Environment Agency heavily contaminated. Therefore if there were to be any run-off guidance and The Control of Pollution (Oil Storage) from stockpiles, it is unlikely to be contaminated. However, to (England) Regulations 200119. prevent suspended sediments entering surface water, exposed areas of soil would be kept to a minimum and any exposed soil The British Standard Code of Practice for Earthworks and 43 would not be left uncovered for long periods of time. In addition, Eurocode 7 would be taken into account. surface run-off would be pumped or drained off the site via a silt Works would adhere to the Waste (England and Wales) trap, minimising any potential impacts. Regulations 2011 (as amended), the Hazardous Waste In order to limit disturbance and mixing between soils, (England and Wales) Regulations 2005 (as amended), the groundwater and surface water during construction, the Environmental Protection Act (1990) and all other relevant construction area would be delineated and no vehicle use would waste legislation. be undertaken outside the working boundary, other than on Based on the above there is no change in the impact of hardstanding or access roads. In order to further limit the 1,800 MW CCGT-only scheme option when compared disturbance, any additional site access roads required would be to the 1,800 MW CCGT with peaking plant scheme option. constructed prior to the commencement of any excavations on the DHC2 site. Current access roads would be used for the DHC2 site. These roads have been constructed with an appropriate camber and drainage system so as to manage heavy rainfall and associated run-off. If any new access roads are required, they would be constructed to a similar standard, so as to manage any additional run-off which occurs. Precautions would be undertaken to ensure the protection of the watercourses in the vicinity of the DHC2 site (River Medway and Damhead Creek). No substance or drainage will be discharged to surface water unless agreed with the Environment Agency and in accordance with the relevant discharge consent. In addition, pollution prevention measures56 such as compliance with National Planning Policy on Waste57 and The Control of Pollution (Oil Storage) (England) Regulations 200119, would be used on site to prevent any contamination of the groundwater. A temporary wheel washing facility would be installed to prevent transfer of soil onto nearby public roads. Excavation and foundation construction would be conducted in a manner that would minimise the size and duration of the excavated area. Dust suppression measures, such as dowsing stockpiles with water, would minimise dust levels on the DHC2 site and in the surrounding environment (minimising the potential of inhalation of contaminants). All manual workers will be required to wear appropriate personal protective equipment (PPE) during the construction phase and strict hygiene measures will be adopted. Unsupervised man entry into excavations would not be permitted. The contractor would provide a silt trap and / or oil interceptor(s)
56 Environment Agency (2002) Integrated Pollution Prevention and Control (IPPC) Sector guidance note combustion activities.
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at a location(s) agreed with the Environment Agency to allow solids or immiscible liquids to settle / separate prior to discharge. The contractor would inspect, empty and maintain any silt traps / interceptors which are installed. A registered waste carrier would remove all sludges or residues collected during cleaning operations off site to a suitably licensed waste disposal facility. Any pumping of water from excavations would be undertaken at such a rate using an appropriately sized pump in order to avoid unnecessary disturbance or erosion. The location of dewatering pipework would be carefully positioned to minimise the risk of damage to underlying geology. The contractor would regularly inspect all dewatering pumps, pipe work and connections. The British Standard Code of Practice for Earthworkscontains detailed methods that would be considered for the general control of drainage on construction sites. Further advice is also available in Eurocode 7: Geotechnical Design43. These would also be taken into account. The 2015 EIR noted that the British Standard Code of Practice for Foundations BS 8004:1986 had been withdrawn and replaced by Eurocode 743 . The compaction of the soils would be minimised by restricting vehicle movements to specified routes and construction areas by segregating construction areas from other sites. In addition, a temporary site compound would be constructed for the parking of construction vehicles and equipment, staff vehicles, and the storage of materials. Storage of fuel would be limited and secure. Temporary diesel storage tanks would be double skinned or contained with an impermeable bund, capable of holding 110% of the tank’s contents. Oil would be stored in accordance with The Control of Pollution (Oil Storage) (England) Regulations (2001)19. Construction machinery would be checked regularly to prevent oil leaks or other emissions from faulty operation. Maintenance of construction machinery would not be allowed on the DHC2 site, which would help to prevent the accidental leakage of lubricating and hydraulic fluids. Refuelling would be limited to a designated area, on an impermeable surface, at a sufficient distance away from any drains or watercourses (this distance would need to be discussed between the Environment Agency and contractors). Spill kits, absorbent geotextiles and absorbent sands would be available on the DHC2 site at all times, in accordance with The Control of Pollution (Oil Storage) (England) Regulations (2001)19 and National Planning Policy on Waste (DCLG, 2014)). Any spills would be cleaned up as soon as possible, according to the Spill Response Plan which would be prepared for the site, with any contaminated sands bagged up and disposed of correctly. Parking of staff vehicles and equipment would only be permitted in designated areas. Spoil generated on the DHC2 site would be stockpiled, tested for waste acceptance criteria and geotechnical composition if necessary and removed off the DHC2 site by a waste contractor by appropriate means or re-used on DHC2 site to fill excavations, if permitted. The excavated spoil would be split into two categories for handling: ‘contaminated’ and
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‘uncontaminated’. This distinction would be determined from the results of samples taken from trial pits and other prior investigations to show the quality and quantity of excavated material. The physical division between the two categories of spoil would be made before it is removed from the DHC2 site. Hazardous Waste and excavated spoil and materials that are classified as giving rise to an environmental hazard would be disposed of at a suitably licensed waste disposal site. Vehicles carrying wastes would be suitably licensed and sheeted / netted or appropriately covered to prevent the escape of waste materials en route. All works would be undertaken with reference to the Waste (England and Wales) Regulations 2011 (as amended), Waste Management Duty of Care, imposed by Section 34 of the Environmental Protection Act 1990 and the Hazardous Waste (England and Wales) Regulations (2005) the Environmental Protection Act (1990) and all other relevant waste legislation. Where spoil is not contaminated, the approach would be to adopt a disposal hierarchy, with the first choice option being to re-use spoil on site wherever possible. The second choice would be to reuse spoil in other developments taking place within the locality of the DHC2 site; however, it is unlikely that the majority of the spoil would be required as part of the construction works on DHC2 site. If these were not possible, the final choice would be for removal of the waste spoil from the DHC2 site for disposal by a suitably licensed contractor. In additions to the mitigation measures proposed in the 2009 ES (above), the recommendations made as a result of the detailed site investigations will be adhered to.
Operation Operation
No areas of the DHC2 site would be accessible to the general The same mitigation measures will be adopted. In addtition public. Therefore, members of the general public were not a conceptual surface water drainage strategy is included considered to be at any risk from contaminants on the DHC2 site within the FRA (Appendix I) to support the planning and no further mitigation measures were considered to be application and should incorporate suitable SUDS. The necessary. residual risk posed to the 1,800 MW CCGT with peaking A full Environmental Management Plan (EMP) with training plant scheme option will be managed by a combination of would be delivered to the operational staff of the plant to ensure the following measures: that all potentially contaminating materials are handled correctly • subscription to the Environment Agency Flood and cleaned up effectively if any spillages take place. Warnings Direct Service; Disposal of all waste materials would be via appropriately • flood resilience measures will be incorporated, licensed disposal contractors. where possible, to adopt flood resilient design techniques for the 1,800MW CCGT with peaking plant scheme option; • flood-proofing or flood resistance; and • a Flood warning and Evacuation Plan (FWEP) will be implemented.
Cumulative Effects
The 2009 ES7 assessment considered the potential cumulative The decommissioning of Kingsnorth Power Station (Units effects of DHC2 in conjunction with the proposed supercritical 1-4) has been completed. However the programme for coal fired power station at Kingsnorth Units 5 and 6 and the demolition is scheduled to continue to 2018, according to proposed Kingsnorth Business Park. Cumulative effects were information submitted in support of the Prior Notification for not considered to be significant. Proposed Demolition application submitted to Medway At the time of publication of the 2014 EIR, the Kingsnorth Units 5 Council. It has therefore been taken into account in the
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and 6 development was not being progressed and, as a result, assessment of cumulative effects. no cumulative effects with new projects in the area were No changes to the potential cumulative effects are predicted. envisaged. The 2014 EIR9 concluded that the cumulative effect of DHC2 and the proposed Kingsnorth Business Park Development would not be significant. At the time of the 2015 EIR publication, the decommissioning of the existing Kingsnorth Power Station (Units 1-4) had commenced. However no changes to the potential cumulative effects were envisaged.
6.7.5 Conclusions The appraisal has considered the effects of the proposed 1,800 MW CCGT with peaking plant scheme option compared to the 1,800 MW CCGT-only scheme option, using information from the previous assessments and information from ongoing work in relation to the Environmental Permit application for DHC2. In addition, an updated FRA has been undertaken which confirms the previous conclusions of low residual risk from all sources of flooding due to the mitigation measures (flood defences) in place. Mitigation measures are clearly set out to manage construction and operational impacts, and these would apply whichever scheme option is progressed. The appraisal concludes that there is no change to the previous 2015 EIR conclusions.
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6.8 Traffic and Infrastructure 6.8.1 Introduction This section considers the potential changes to effects on traffic and infrastructure during construction and operation as a result of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the already consented 1,800 MW CCGT-only scheme option. 6.8.2 Baseline Conditions The traffic and infrastructure assessment chapter presented in Chapter 16 of the 2009 ES summarised the baseline conditions, in terms of the local road network, access and provision of public transport. This section presents a summary of that baseline description. Whilst there have been some changes as a result of local developments (e.g. Kingsnorth Industrial Estate), traffic changes arising from these have been at least partly offset by the closure of Kingsnorth Power Station. Given the nature of the location, the baseline is therefore considered to be largely unchanged and therefore representative of the current arrangements and conditions at the time of publication of this report.
The local road network in the vicinity of the Damhead Creek 2 site is shown in Figure 1. The M2 runs north-west/ south-east approximately 11 km south-west of the application site, west of Strood. The major road link to the M2, from the application site, is the A289, Northern Relief Road, and then the A228, that passes to the north-west of the application site, from the Isle of Grain.
Access to the existing Damhead Creek CCGT Power Station is provided by a dedicated access road that leads around the Kingsnorth Industrial Estate, immediately north-west of the existing Damhead Creek CCGT Power Station, and connects with Stoke Road. Roper’s Lane connects Stoke Road to the A228 approximately 1.1 km north-east of the junction for Hoo St. Werburgh and around 1.2 km south of High Halstow.
There are no bus stops serving the site. The nearest stops are on Main Road, Hoo St Werburgh, on the A228 Ratcliffe Highway and in Stoke. The local rail line is for freight only, the nearest passenger station being Strood Rail Station, located 12 km west of the application site.
Within the Hoo Peninsula access to public transport is generally poor, with a very small proportion of the working population using public transport to travel to work. The consequence of the limited provision and use of the public transport system is that private vehicle ownership is high. The majority of people in the Peninsula travel to work by private transport over an average distance of approximately 15 km.
The application site is remote in terms of neighbouring residential areas and, as such, there is limited scope for walking or cycling to work. The cycle catchment area encompasses Hoo St Werburgh, High Halstow and Stoke; however, these are relatively small villages and unlikely to be home to significant numbers of appropriately skilled construction or operational staff. 6.8.3 Differences Between Proposed Scheme Options There is no difference in the construction activity intensity or the number of staff required during operation of the proposed 1,800 MW CCGT with peaking plant scheme option compared to the 1,800 MW CCGT-only scheme option, although depending on the approach proposed for construction of the option, the duration of the construction programme may increase for the 1,800 MW CCGT with peaking plant scheme option (with the peaking plant being installed after the CCGT elements are constructed). Similarly, it is envisaged that there will be no significant increase in the construction workforce numbers accessing the site at any one time in the event that the with peaking option is selected.
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6.8.4 Appraisal of Environmental Impacts and Mitigation Table 6.8.1: Appraisal of Traffic and Infrastructure Effects
1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Construction
The construction workforce will peak at around 1,000 personnel Depending on the approach to be taken for the per day, with around 400 vehicles per day and approximately construction of the 1,800 MW with peaking plant option, 100 heavy goods vehicles (HGVs) per day expected. the construction programme is potentially greater than the In addition to staff transport movements, construction traffic will original 36 months anticipated for the 1,800 MW CCGT- consist of civil works traffic, mechanical works traffic and a small only scheme option. number of abnormal loads for components. However, construction working hours and construction Construction work will be limited to Monday to Saturday 7:00- intensity will not change, so the majority of construction 19:00 hours. Therefore the bulk of the workforce traffic will occur staff traffic will still be outside peak hours, and HGV between the hours of 06:00-07:00 and 19:00-20:00. The HGV movements will be spread across the day. movements will be spread evenly over the course of the working No significant impacts are predicted on the local road day, at a rate of around 6 vehicles per hour between 8:00-18:00. network based on the previous assessment. The Transport Assessment identified Stoke Road/ Roper’s Lane The CEMP will be udpdated as required and implemented, as being the most sensitive road, but did not identify any no matter which scheme option is selected for significant adverse effects on the local road network due to implementation. DHC2 construction. No change was predicted for the 1,200 MW scheme. A CEMP was prepared and submitted to Medway Council on 3rd November 2015 to fulfil the requirements of condition 11 of the deemed planning permission. The CEMP details the construction and environmental management for the project to ensure all requirements of the relevant CEMP conditions set within the deemed planning permission are understood, communicated and followed at all times during the construction phase of the project. In addition this CEMP supports discharge, or compliance with conditions 6, 12, 13, 14, 15, 16, 17 and 17A of the deemed planning permission. The CEMP outlines the responsibilities of the key roles during construction to ensure environmental protection requirements and objectives of the project are adhered to, and sets out agreed mitigation measures. The CEMP was approved under planning reference MC/15/4047 on 23rd December 2015.
The 1,800 MW CCGT-only scheme option required Abnormal The number of abnormal loads required for the proposed loads to be of the order of 15 to 20 over the 36 month 1,800 MW CCGT with peaking plant scheme option is construction phase. The transportation of abnormal loads can likely to be comparable to those proposed for the lead to disruption or delays and is considered to be of moderate 1,800MW CCGT-only scheme (of the order of 15 to 20 significance. over the construction phase). The significance of effects Transportation of these loads will be timed following consultation (disruption and delays) on the local road network would with the relevant authorities to minimise disruption to the other therefore be comparable to the 1,800 MW CCGT-only road users. scheme option given the frequency of occurrence and timing to minimise disruption. The Construction Traffic Management Plan (CTMP) was prepared and submitted to Medway Council on 3rd November The CTMP will be updated as required, in consultation with 2015 to fulfil the requirements of conditions 18 and 19 of the the local authority, and implemented no matter which Section 90 Direction. The CTMP deals with impacts on the local scheme option is selected for implementation. road safety, traffic management and road network condition monitoring during the construction of the main power station area and the delivery of abnormal loads for the project. The document is generally associated with the A289 and A228 (Peninsula Way), Ropers Lane, Stoke Road, Eschol Road and includes the length of the road servicing the access to Damhead
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Creek Power Station. The CTMP encompasses the construction of all buildings, structures, systems and components of the DHC2 development. It applies to all personnel working at the site, all Contractor employees, Client representatives and any other visitor to this location during the entire construction phase of the project. The CTMP was approved under planning reference MC/15/4047 on 23rd December 2015.
Operation
The 1,800 MW CCGT-only scheme option would require No change to the number of operational/ maintenance staff approximately 50 staff to satisfy daily operational and is anticipated, so no changes to the predicted effects are maintenance requirements. envisaged. Traffic associated with the full operation of the plant would be of The GTP will be updated if required and implemented no the order of 40 vehicles per day, each making a return journey, matter which scheme option is selected for predominantly in the local area. implementation. The addition of 40 vehicles per day on the local road network would not be sufficient to cause any roads included within the study area to operate above capacity and therefore the impact is not considered to be significant. A Green Travel Plan (GTP) was prepared and submitted to Medway Council on 3rd November 2015 to fulfil the requirements of condition 10 of the deemed planning permission. The GTP was prepared having cognisance to both national and local transport policy, and also seeks to build upon the existing ScottishPower operated transport schemes used at various locations throughout the UK. This GTP identifies the strategy for supporting DHC2 staff to travel to the site by sustainable travel modes. ScottishPower are committed to the implementation of the GTP once DHC2 is operational. Once DHC2 is operational there will be an opportunity to collect qualitative and quantitative travel information from staff which will be used to update the GTP. The GTP was approved under planning reference MC/15/3907 on 23rd December 2015.
The 1,800 MW CCGT-only scheme option would require up to Planned major outages would still be expected to occur 200-300 staff on site during outages for maintenance, temporary approximately every six years, with up to 200-300 staff on staff would visit the site for a period of approximately one month. site during the outage. No significant changes to the Planned major outages were expected to occur approximately predicted traffic effects are anticipated. every six years. The operational traffic volume is significantly less than the anticipated construction traffic for DHC2. As such, maintenance activities will not cause any roads within the study area to operate above capacity and therefore not increase delays or congestion on the local road network.
Cumulative Effects
Construction The decommissioning of Kingsnorth Power Station (Units The Transport Assessment57 identified potential for the 1-4) has been completed. However the programme for construction of DHC2, Kingsnorth Power Station Units 5 and 6 demolition is scheduled to continue to 2018, according to and Kingsnorth Business Park to cause potential congestion and information submitted in support of the Prior Notification for delays on Stoke Road and Roper’s Lane between 06:00 and Proposed Demolition application submitted to Medway Council. It has therefore been taken into account in the
57 Parsons Brinckerhoff Ltd (2009b) Transport Assessment
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
07:00, and proposed active management of construction traffic assessment of cumulative effects. through the implementation of a Construction Transport The proposed 1,800 MW CCGT with peaking plant Management Plan, to avoid these effects. scheme option is not expected to increase the number of The road improvements proposed as part of the Kingsnorth construction staff and there would be minimal additional Business Park development, anticipated to increase the capacity HGV movements compared to the CCGT-only scheme of Roper’s Lane, have been completed. option, although the duration may increase depending on By the time of publication of the 2014 EIR, the development of the approach to be taken for construction of the CCGT and Kingsnorth Units 5 and 6 had been abandoned and, as a result, OCGT units. A longer construct ion programme could no cumulative effects were predicted. result in construction works continuing at the same time as other developments, however no such developments have However, the decommissioning of the existing Kingsnorth Power been identified and the effects of construction traffic for Station (Units 1-4) was expected and was, therefore, considered DHC2 are not expected to be significant. in the traffic and infrastructure assessment. In addition, the road improvements associated with the Kingsnorth Business Park development had been carried out to improve access to the site from the A228. The 2014 EIR8 concluded that the cumulative effect of DHC2, the proposed Kingsnorth Business Park Development and the decommissioning of the existing Kingsnorth Power Station (Units 1-4) would not be significant. A Construction Transport Management Plan would still be necessary to minimise or eliminate delays or congestion episodes along the access route in the peak hour. Abnormal loads would be managed through the CTMP. The CTMP has been prepared and approved by Medway Council. The report addresses all potential issues resulting from the increased demand on the local transport infrastructure. Potential impacts in relation to the transportation of abnormal loads associated with the cumulative developments were not anticipated to be significant. At the time of the 2015 EIR9 publication, the decommissioning of the existing Kingsnorth Power Station (Units 1-4) had commenced. The 2015 EIR assessment noted that the number of staff and HGV movements would be slightly greater, but no significant cumulative effects were anticipated.
Operation No changes to the potential cumulative operational effects It was anticipated that during operation of the 1,800 MW CCGT- are anticipated. only scheme option and the Kingsnorth Business Park, Roper’s Lane and Stoke Road would not exceed the capacity threshold and the impact would therefore not be significant.
Mitigation Measures
Construction The same mitigation measures would be adopted including During construction, the use of the A289 will bypass local town the implementatation of the approved Construction centres to eliminate avoidable congestion. Transport Management Plan (updated as required) and any supplementary consultation with Highways England Car sharing will be encouraged and a minibus service will be and Medway Council. provided by contractors so as to reduce the number of vehicles visiting the construction site. No additional mitigation measures are required for the CCGT with peaking plant scheme option. The approved CTMP incorporates all measures required to minimise impact of construction phase traffic.
Operation The approved Green Travel Plan is valid for whichever No perceivable impact is expected during the operation of DHC2 option is selected for construction, and no additional and no mitigation measures are deemed necessary. However, mitigation measures are required for the CCGT with the 2015 EIR noted that a GTP would be prepared and peaking plant scheme option.
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
implemented by ScottishPower in accordance with condition 10. The approved GTP incorporates all measures required to minimise the impact of operational phase traffic, and will be updated and maintained as a live document once the development becomes operational.
6.8.5 Conclusions The proposed 1,800 MW CCGT with peaking plant plant scheme option will not require significant changes to the number of construction staff and associated traffic compared to the 1,800 MW CCGT- only scheme option, although the duration of construction works may increase depending on the construction approach to be used. As a result, the conclusion of the construction phase assessment remains as for the 1,800 MW CCGT-only scheme option as assessed in the 2015 EIR, with no significant adverse effects on the local road network predicted, with the exception of potential occasional short term disruption and delays caused by a small number of abnormal loads. To mitigate any such disruption the approved TMP (approved under planning reference MC/15/4047 on 23rd December 2015) will be implemented no matter which scheme option is progressed as it addresses all potential issues resulting from the increased demand on the local transport infrastructure.
During operation, the proposed 1,800 MW CCGT with peaking plant scheme option will not require any additional staff compared to the 1, 800 MW CCGT-only scheme, so no changes to the predicted effect of operational traffic impacts are anticipated.
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6.9 Cultural Heritage 6.9.1 Introduction This section considers the potential changes to effects on archaeology and built heritage during construction and operation as a result of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the already consented 1,800 MW CCGT-only scheme option. 6.9.2 Baseline Conditions The cultural heritage assessment chapter presented in Chapter 17 of the 2009 ES9 summarised the baseline conditions, in terms of statutory and non-statutory designations, palaeo-environmental background and historic land use. This section presents a summary of that baseline description, with updates where necessary (for example with reference to the archaeological investigations that have been undertaken in the discharge of the Section 90 Direction conditions), which is assumed to be largely unchanged and therefore representative of the archaeology and built heritage at the application site at the time of publication of this EIR.
Historic Environment Designations There are no Scheduled Monuments within the site boundary; however, Fort Darnet, Darnet Ness is located approximately 1.9 km to the south-east of the application site.
There are no listed buildings within the application site; however, there are three listed buildings situated within a 2 km radius of the application site, as follows:
• Cold Arbour Farm House (Grade II), approximately 1.5 km north of the application site;
• Lancers Farm House (Grade II), approximately 1.1 km west of the application site; and
• White Hall House (Grade II), approximately 1.1 km to the north of the application site.
There are no Conservation Areas within the application site, or within a 2 km radius of the application site.
The application site is located in an Archaeological Notification Area, a non-statutory designation used by Kent County Council and Medway Council to indicate areas of recognised archaeological potential.
History of the Site and Surrounds The marshes of the Medway Estuary are rich in palaeo-environmental alluvial deposits. These deposits can provide information about the environment of the area during the prehistoric period. Holocene alluvial deposits have been identified on the existing Damhead Creek CCGT Power Station site, the application site and at the adjacent site of the previously proposed Kingsnorth Units 5 and 6.
Previous geoarchaeological surveys (including borehole investigations) undertaken on and around the application site identified evidence of a Pleistocene interglacial deposit with archaeological potential, which is considered to be of local and regional importance. Although no palaeo-environmental material was recovered from the Holocene alluvium, evidence of charcoal, burnt flint and possible ceramic material recovered from a borehole taken at Kingsnorth suggests that the Holocene alluvium at least represents considerable potential for archaeological evidence of human activity during the last 7,000 years.
Evidence has been revealed by archaeological excavation also undertaken on and around the application site for multi-period activity from the Late Bronze Age into the Early Iron Age, when the application site became a part of the early agricultural landscape of the Hoo Peninsula. Situated on low- lying land south-west of the main area of arable cultivation and settlement, the application site was used for grazing, and possibly seasonal salt-working.
During the 2nd and 3rd centuries AD, a Romano-British pottery production site was established within the vicinity of the application site, although its precise location has not been revealed by previous archaeological and geophysical investigations.
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During the early medieval period, the application site once again became part of the pastoral landscape of the Hoo Peninsula, whilst flooding during the medieval period prompted the building of sea walls along the banks of the Damhead Creek and the Damhead Fleet. These walls may have survived, albeit in a modified and improved form into the 20th century. From 1912, the application site underwent its most intensive period of use, when the Royal Naval Air Service (RNAS) Kingsnorth Naval Airship Station was established. The station was of considerable significance in the history of British naval aviation, despite the fact that it closed just eight years later. The majority of this activity was concentrated to the north-west of the site, outside the application site.
Summary of Findings of Investigations Undertaken Subsequent to the Section 90 Direction Planning conditions 45, 46 and 47 of the Section 90 Direction relate to archaeological investigations during construction of DHC2 (see Section 3).
Condition 45 requires the submission and approval of a scheme of archaeological investigation works prior to the commencement of development. A review of existing geo-archaeological works within and adjacent to the development site, a geophysical survey and a trial-trench evaluation were required. Areas 2 and 3 have been previously investigated and been shown to be devoid of archaeological remains or containing remains buried beneath up to 10 m of PFA therefore not likely to be impacted upon by development, these areas were discharged under planning reference MC/12/0875 on 30 April 2012 (with reference to planning permission MC/08/0370). Work to discharge condition 45 therefore focuses on Area 1. The geo-archaeological review and the geophysical survey of Area 1 were completed in October 2012. A Written Scheme of Investigation (WSI) for Area 1 was subsequently prepared, concerned principally with surface trenching. ScottishPower has made submissions relating to conditions 45 and 46 and is working with the Kent County Council Archaeological Officer (KCCAO) and Medway Council to achieve discharge of these conditions. This section summarises the key findings presented in the submissions.
The geo-archaeological review of Area 1 concluded that sedimentary sequences considered to be of regional to national importance are preserved in a small area within the extreme northern part of Area 1. The geophysical survey undertaken in Area 1 did not identify any anomalies of probable archaeological origin on the western part of Area 1, only areas of modern disturbance and made ground. Geophysical anomalies indicating possible archaeological features were identified in the eastern part of Area 1 (near- surface archaeology), but over most of the rest of the area, the results were consistent with prior disturbance on the site and the presence of substantial made ground and ferrous debris.
The surface trenching required by the WSI in Area 1 was commenced in July 2013. The first 1% trial trenching showed that the ground had been highly disturbed during the construction of the existing Damhead Creek CCGT Power Station and that significant amounts of made ground and pulverised fuel ash (PFA) had been deposited on the site thereafter, particularly on the western side of Area 1. However, archaeological remains may survive in pockets beneath made ground on the eastern and northern parts of Area 1, though they are still highly disturbed and truncated by previous activity.
A second 1% trenching programme, requested by the Kent County Council Archaeology Officer (KCCAO), was undertaken in Area 1 in November 201358. Taken with the results from the previous phase of trenching59, the second phase of evaluation has shown that ground disturbance from previous construction activities associated with the building of the existing Damhead Creek CCGT Power Station has affected many areas of the application site. The western side of Area 1, in particular, shows high levels of made ground and PFA deposited in these areas. No archaeology was found to survive below these levels in the trenches excavated during this phase of work. The central portion of Area 1 also contained no new evidence for surviving archaeology. However, towards the south-eastern side of the Area 1, archaeological features have been found to have survived below thick, compact alluvial deposits. This clay layer matches that recorded during previous excavations at the location of the existing pipeline to the south, where it was found to seal archaeology including large ditches and pits, Roman pottery and other features that may be Saxon. It is
58 Scottish Power (2013f) Interim Report on an Archaeological Evaluation 59 Scottish Power (2013g ) Archaeological Evaluation, Written Scheme of Investigation
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likely that the features recorded during this phase of the trial trenching represent the same phase of activity as those recorded in the larger excavations immediately to the east. There are no plans to build over the south-eastern area highlighted.
No trace of the alluvial deposits was recorded to the south-west. This suggests that all traces of previously surviving archaeology have been truncated in this area during past development, or perhaps more likely, the archaeological activity recorded in south-eastern side and earlier excavations to the south ceased towards the north and west. Taken with the results of the previous phase of archaeological works it is clear that archaeological remains are only present in the south-eastern part of Area 1.
In summary the only remaining areas of archaeological interest identified by the surveys are the extreme northern part and the south-eastern part of Area 1 and a further core sample will be taken in the northern part of Area 1 for analysis and historical recording of results. SP will continue to work with the KCCAO to discharge the remaining conditions prior to commencement of the proposed development.
Condition 47 was reworded as part of the 2015 EIR9 (see Appendix A) following discussions with the KCCAO and Medway Council regarding the conclusions of the archaeological surveys undertaken to date. The revised condition will ensure that any significant archaeological finds discovered during construction works are reported and an appropriate way forward is agreed. 6.9.3 Differences Between Proposed Scheme Options There is no difference in the land take required for the proposed 1,800 MW CCGT with peaking plant scheme option. Appraisal of Environmental Impacts and Mitigation
Table 6.9.1: Appraisal of Cultural Heritage Effects
1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Construction
Initial groundworks, such as the creation of general formation The development footprint and construction method for levels, the setting out and consolidation of access road for plant foundations will be the same as that described for the and machinery, can impact to a greater or lesser degree upon 1,800 MW CGGT only scheme option, so no changes to buried archaeological remains, depending upon the nature and the predicted effects are anticipated. extent of these works. Potential archaeological remains of regional to national Due to the nature of the below-ground deposits, it was importance may be present in the northern and south- considered likely that most, if not all the structures would be eastern parts of Area 1, but no such remains are constructed with piled foundations. The 2015 EIR9 noted that the considered to be present in Areas 2 or 3. 1,800 MW CCGT-only scheme option would increase the Based on the indicative layouts shown in Figures 6a and footprint of the development and mean larger areas will 6b, the south-eastern area is will not be impacted but the potentially be affected, particularly Area 3. northern area could be. Piling and excavation were considered likely to affect the upper ScottishPower are working to discharge conditions 45 and levels of the Holocene alluvial deposits (where present), which 46 to the satisfaction of Kent County Council Archaeology may contain the remains of activity that has occurred on site and Medway Council by arranging for a suitable additional since the Bronze Age. core sample to be taken from the northern area of interest, Potential archaeological remains of regional to national undertaking the appropriate reporting and updating the importance may be present in the northern and south-eastern historical records sought by the regulators. parts of Area 1, but no such remains are considered to be Condition 47 (as revised) will ensure appropriate mitigation present in Areas 2 or 3. for any significant finds during construction in this area. The 2015 concluded that based on the indicative layouts shown in Figures 6a and 6b (2015 EIR), the south-eastern area was unlikely to be impacted but the northern area could be. ScottishPower are working to discharge conditions 45 and 46 to the satisfaction of Kent County Council Archaeology and Medway Council by arranging for a suitable additional core sample to be taken from the northern area of interest, undertaking the appropriate reporting and updating the historical records sought by the regulators. Condition 47 (as revised) will ensure appropriate mitigation for
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any significant finds during construction in this area.
The cutting of service trenching and connections can cause The area of potential archaeological interest in the significant localised impacts upon buried palaeo-environmental northern part of Area 1 is still likely to be affected by the and archaeological remains. Remains elsewhere in the DHC2 proposed 1,800 MW CCGT with peaking plant scheme site were noted from 80 cm below ground level (bgl) to at least option. The only other area of archaeological interest, in 5 m bgl. the south-eastern part of Area 1, will not be affected. Considering the low likelihood of remains across most of the site, Condition 47 (revised as part of the 2015 EIR9 and to be the impacts of the 1,200 MW scheme on the archaeological retained whichever scheme option is progressed) will resource were anticipated to be: ensure that any significant archaeological finds discovered • if remains survive on the site dating to the Palaeolithic, during construction are reported and an appropriate way Mesolithic, Neolithic, late Bronze Age and Roman periods, forward is agreed. the construction impacts on this regionally significant No significant changes to the potential construction phase resource would be moderate adverse without mitigation; and effects on archaeological remains are envisaged. • if remains survive on the site dating to the palaeo- environmental Iron Age, Saxon, medieval, post-medieval and modern periods, the construction impacts on this regionally significant resource would be slight adverse without mitigation. The 2015 EIR noted that the increase in the footprint of development for the 1,800 MW CCGT-only scheme option would mean the area of potential archaeological interest in the northern part of Area 1 was likely to be affected but the south-eastern part of Area 1 was unlikely to be affected. It proposed that Condition 47 was reworded (see 2015 EIR Appendix A) following discussions with the KCCAO and Medway Council and the revised condition would ensure that any significant archaeological finds discovered during construction are reported and an appropriate way forward is agreed. The 2015 EIR concluded that no significant changes to the potential construction phase effects were envisaged.
Operation
No adverse impacts to the archaeological resource were If discovered on site during construction, the palaeo- anticipated to be caused by the operation of the 1,800 MW environmental deposits will be monitored to ensure they CCGT-only scheme option. are not substantially dewatered during construction. Palaeo-environmental deposits such as peat and alluvium No changes to the potential operational phase impacts on (should they be present) may be affected by de-watering the archaeological resource are envisaged. associated with the use of piled foundations. Should this type of deposits become de-watered, it may become desiccated and lose its palaeo-environmental value. If discovered on site, the palaeo-environmental deposits would be monitored for a period after construction in order to ascertain if dewatering is taking place and appropriate action would be taken if this is found to be occurring.
Cumulative Effects
The 2009 ES7 assessment considered the potential cumulative The decommissioning of Kingsnorth Power Station (Units effects of DHC2 in conjunction with the proposed supercritical 1-4) has been completed. However the programme for coal fired power station at Kingsnorth Units 5 and 6 and the demolition is scheduled to continue to 2018, according to proposed Kingsnorth Business Park. Cumulative effects, which information submitted in support of the Prior Notification for would relate to the visual impact of the projects to sites of Proposed Demolition application submitted to Medway
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
historic interest, were not considered to be significant. Council. It has therefore been taken into account in the By the time of publication of the 2014 EIR, the development of assessment of cumulative effects. Kingsnorth Units 5 and 6 had been shelved and, as a result, no No changes to the potential cumulative effects on cultural cumulative effects were predicted. heritage are envisaged. The decommissioning of the existing Kingsnorth Power Station Units 1-4 was still expected and was therefore considered. The 2014 EIR8 concluded that no cumulative effects on cultural heritage were anticipated. At the time of the 2015 EIR9 publication, the decommissioning of the existing Kingsnorth Power Station (Units 1-4) had commenced, was therefore considered, and no cumulative effects on cultural heritage were anticipated.
Mitigation Measures
Construction ScottishPower are working to discharge conditions 45 and Since the nature and survival of the archaeological resource on 46 to the satisfaction of Kent County Council Archaeology the DHC2 site was not fully understood at the time of the 2009 and Medway Council by arranging for a suitable additional ES and subsequent 2014 EIR, an archaeological watching brief core sample to be taken from the northern area of interest, was recommended to be undertaken during the construction undertaking the appropriate reporting and updating the stage of the project. historical records sought by the regulators. Furthermore it was recommended that, prior to construction, Condition 47 (as revised) will ensure appropriate mitigation archaeological trial trenching be carried out within areas of for any significant finds during construction in this area construction impact. . It was noted that further sampling of palaeo-environmental
deposits, may be required, although some mitigation of this resource has already been carried out by previous investigations on the DHC2 site. A geophysical survey and a trial-trench evaluation had been completed at the time of the 2015 EIR. ScottishPower are continuing to work to discharge conditions 45 and 46 to the satisfaction of Kent County Council Archaeology and Medway Council by arranging for a suitable additional core sample to be taken from the northern area of interest, undertaking the appropriate reporting and updating the historical records sought by the regulators.
Condition 47 (as revised) will ensure appropriate mitigation for any significant finds during construction in this area.
Operation Although the 1,800 MW with peaking plant scheme option A requirement for archaeological mitigation during the will extend into Area 3, no additional surveys in this area operational phase of DHC2 was not anticipated. are necessary in the light of the findings of previous evaluation and condition discharge by Goodman. The De-watering of peat or alluvial deposits may occur and should be archaeological condition attached to MC/08/0370, monitored with any necessary mitigation measures agreed with including the archaeology related to plots 2B and 3 (Area 2 the Council. and area 3) was discharged under planning reference The 2015 EIR noted that although the 1,800 MW CCGT-only MC/12/0875 on 30 April 2012. scheme option extended into Area 3, no additional surveys were Any significant palaeo-environmental deposits discovered necessary in light of the previous evaluation findings and on site during construction will be monitored during the condition discharge by Goodman. The archaeological condition operation of the proposed 1,800 MW CCGT with peaking attached to MC/08/0370, including the archaeology related to plant scheme option plots 2B and 3 (Area 2 and area 3) was discharged under planning reference MC/12/0875 on 30 April 2012.
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6.9.4 Conclusions The footprint of development for the proposed 1,800 MW CCGT with peaking plant scheme option will remain the same, therefore the area of potential archaeological interest in the northern part of Area 1 is still likely to be affected. ScottishPower are working to discharge conditions 45 and 46 to the satisfaction of Kent County Council Archaeology and Medway Council by arranging for a suitable additional core sample to be taken from the northern area of interest, undertaking the appropriate reporting and updating the historical records sought by the regulators. Condition 47 (revised as part of the 2015 EIR9) will ensure that any significant archaeological finds discovered during construction are reported and an appropriate way forward is agreed.
Overall the conclusions of the previous assessment and mitigation measures proposed remain unchanged from the previously consented scheme.
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6.10 Socio-Economics 6.10.1 Introduction This section considers the potential changes to socio-economic effects during construction and operation as a result of the proposed 1,800 MW CCGT with peaking plant scheme option, compared to the already consented 1,800 MW CCGT-only scheme option. 6.10.2 Baseline Conditions The socio-economics assessment chapter presented in Chapter 18 of the 2009 ES summarised the baseline conditions, in terms of the local economy and employment information. This section presents an update of that baseline description, using data which are available from the Office of National Statistics (ONS).
The application site is located on the Hoo Peninsula in Medway, North Kent. The population of Medway is around 274,10560. Strood, on the western border with Gravesham, is the administrative centre of Medway. The 2011 census61 found that the population of Medway increased by 5.9% between 2001 and 2011 (with an even higher increase in the Hoo Peninsular ward), but the population is ageing with a decrease in the number of 0-18 year olds and an increase in 19-65 and 65+ year olds. Levels of deprivation in Medway are higher than average for England and Wales (Medway Council, 2011b).
According to the Kent and Medway Structure Plan 200662, Medway has the largest labour force in Kent with a large number of residents commuting to London to work. The average distance travelled to work by the economically active people of the Peninsula is 15 km, compared with 13 km for Medway and 10 km for the South East.
Table 6.10.1, based on information from the British Register and Employment Survey63, shows the sector breakdown of the working population of the Hoo Peninsula and Medway, compared with regional and national details from 2013.
Table 6.10.1: Employees in Employment
Sector Hoo Peninsula Medway (%) South East England (%) England (%) (%) Agriculture, forestry and fishing 1.5 0.1 0.7 0.1 Mining and quarrying 0.0 0.1 0.1 0.1 Manufacturing 5.5 8.3 6.4 8.3 Electricity, gas, steam and air conditioning supply 12.2 0.8 0.3 0.8 Water supply; sewerage, waste management and 5.8 1.1 0.7 1.1 remediation activities Construction 10.4 6.4 4.7 6.4 Wholesale and retail trade; repair of motor vehicles and 6.8 16.8 17.2 16.8 motorcycles Transportation and storage 12.4 5.3 4.1 5.3 Accommodation and food service activities 6.3 6.2 7.3 6.2 Information and communication 0.8 2.1 6.2 2.1
60 Office of National Statistics (ONS) (2015) Population estimates for UK, England and Wales, Scotland and Northern Ireland, Mid-2014 61 Medway Council (2011) Medway Census Report 2011 62 Kent County Council & Medway Council (KCCMC) (2006) Kent and Medway Structure Plan – Mapping out the future. 63 Office of National Statistics (ONS) (2015) British Register and Employment Survey 2009-2013
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Sector Hoo Peninsula Medway (%) South East England (%) England (%) (%) Financial and insurance activities 0.0 3.2 3.3 3.2 Real estate activities 0.3 1.1 1.4 1.1 Professional, scientific and technical activities 2.7 3.4 8.0 3.4 Administrative and support service activities 9.7 7.7 8.0 7.7 Public administration and defence; compulsory social 0.9 4.9 3.6 4.9 security Education 12.1 13.0 10.5 13.0 Human health and social work activities 8.0 14.6 12.3 14.6 Arts, entertainment and recreation 3.4 3.0 2.8 3.0 Other service activities 1.2 2.0 2.4 2.0 Note: Entries denoted in bold indicate the top three employment sectors in each group. The main employment sectors in the Hoo Peninsular are energy, transport & storage and education, while in Medway, the South East and England, the main employment sectors are wholesale and retail trade, education and health. ScottishPower already own and operate Damhead Creek power station with a number of employees living within the immediate area. Many local businesses have been awarded contracts and continue to secure work across a large range of activities, in relation to both the existing and planned power stations.
Medway has two very large scale and regionally important employment sites at Kingsnorth and Grain. Due to the concentration of nationally significant infrastructure on the Hoo Peninsula and the Isle of Grain, Medway is vital to the safe functioning of London and the wider South East. In summary this comprises:
• Damhead Creek Power Station;
• Kingsnorth Power Station (which has been decommissioned);
• Grain Power Station;
• LNG storage at Grain – supplying 25% of England’s storage capacity and one of the largest facilities of its type in the world;
• BRITNED – a two way electrical interconnector at Grain linking the UK National Grid with that in the Netherlands and mainland Europe more widely;
• Aviation fuel storage (BP) – again at Grain and supplying Gatwick and Heathrow airports by pipeline; and
• Thamesport – the fifth largest container port in the UK and the first fully to be mechanised.
The trends in the unemployment rates for Medway and Kent follow the fluctuations observed for Great Britain, with Medway tending to be slightly higher. The ONS recorded an unemployment rate of between 6.9 and 5.8% for England and Wales for the four quarters in 201464. Medway was slightly higher with a figure of 7.4% for the period January-December 201565. The 2011 Census63 found the proportion of people in Medway with no qualifications was similar to the England and Wales average (22.9% in Medway compared to 22.7% across England and Wales). The level of those with is two or more A-levels is also similar to the England and Wales average (12.7% and 12.3% respectively) but the level of university educated people is lower in Medway compared to England and Wales (19.1% and 27.2% respectively). 6.10.3 Differences Between Proposed Scheme Options
64 Office of National Statistics (ONS) (2015) Summary of Labour Market Statistics 65 Office of National Statistics (ONS) (2015) Regional Labour Market: Summary of Headline Indicators
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The proposed 1,800 MW CCGT with peaking plant scheme option, when compared to the already consented 1,800 MW CCGT-only scheme option is anticipated to have either the same duration of construction phase, or potentially a longer construction phase, depending on the selected approach to construction of the CCGT and OCGT units and whether the OGCT unit would be constructed at the same time as the CCGT units or subsequently. This is not expected to change the number of construction workers required, but may increase the duration of their work.
No changes to the operational staffing requirements are anticipated for the proposed 1,800 MW CCGT with peaking plant scheme option compared to the already consented 1,800 MW CCGT-only scheme option. 6.10.4 Appraisal of Environmental Impacts and Mitigation Table 6.10.2: Appraisal of Socio-Economic Effects
1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Construction
During the peak of construction, assuming development of The construction programme for the proposed 1,800 MW DHC2 in one phase, the workforce would peak at approximately CCGT with peaking plant scheme option is anticipated to 1,000 staff per day. Up to 40% could be recruited from local have either the same duration of construction phase, or residents. The 2015 EIR noted that a marginal increase in potentially a longer construction phase, depending on the manpower, for the 1,800 MW CCGT-only scheme option, would selected approach to construction of the CCGT and OCGT result in more beneficial socio-economic effects including longer units and whether the OGCT unit would be constructed at employment of local people and sourcing of local goods, the same time as the CCGT units or subsequently. This is services and contractors, and indirect employment benefits. not expected to change the number of construction The construction period, assuming one phase development, will workers required, but may increase the duration of their last for approximately 36 months. work. Works machinery will be required for all aspects of the DHC2 It is ScottishPower’s preference that much of the workforce construction and may be sourced from local plant hire will be recruited locally, and measures to facilitate this are companies. set out in the Section 106 Agreement between ScottishPower and Medway Council. This requires The civil works that would constitute the initial stages of the ScottishPower have submitted a Construction Training and construction will require a small unskilled workforce. The Employment Method Statement to the Council for its subsequent mechanical and electrical works will utilise a larger written approval. Following the Council's written approval workforce with more specialised skills. of the Construction Training and Employment Method It is hoped much of the workforce will be recruited locally, and Statement, and during the construction phase of DHC2, measures for this are set out in the Section 106 Agreement ScottishPower will use reasonable endeavours to comply between ScottishPower and Medway Council. ScottishPower with the approved Construction Training and Employment have submitted a Construction Training and Employment Method Statement. Method Statement to the Council for its written approval. The total investment in the proposed 1,800 MW CCGT Following the Council's written approval of the Construction with peaking plant scheme option would be similar to that Training and Employment Method Statement, and during the of the proposed 1,800 MW CCGT-only scheme option construction phase of DHC2, ScottishPower will use reasonable (approximately £600-£750 million) and still represents a endeavours to comply with the approved Construction Training substantial investment for the region. Up to 30% of the and Employment Method Statement. capital investment in a CCGT plant could be spent in the The money invested into the local economy, in terms of local area and region more generally. construction staff wages and project expenditure on local goods, In summary, the socio-economic benefits from the 1,800 services and contractors, will generate further economic activity MW CCGT with peaking plant scheme option would be and indirect employment benefits. Throughout the construction comparable to the CCGT-only scheme option, and the of DHC2, every effort will be made to ensure that as much of the overall conclusions of the assessment of the construction investment as is possible would remain in the region. phase remain the same. Total investment in DHC2 will be of the order of £750 million.
Typically up to 30% of the capital investment in a CCGT plant will be spent in the local area and region more generally. Workers from outside the area were considered to be likely to commute weekly to the DHC2 site. The temporary accommodation requirements will be provided by local hotels and guesthouses, or privately, generating more business in this
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
sector of the local economy, and increasing spending in the area. It was therefore considered that there will be a moderate positive impact on local businesses. In general, it was expected that there would be a high positive socio-economic impact in the area from the construction of DHC2. The 2015 EIR report noted that although the benefits from the 1,800 MW CCGT-only scheme option would be slightly greater than the previously assessed 1,200 MW scheme, the overall conclusions remain the same.
Operation
Approximately 50 staff would be required for roles and tasks There is no anticipated change to the number of daily associated with the daily operational and maintenance operational and maintenance staff required to operate the requirements. These jobs would be permanent and non- proposed 1,800 MW CCGT with peaking plant scheme seasonal, and would exist for the operational lifetime of DHC2, option, or to its expected lifetime. As such the previous which is expected to be approximately 35 years. assessment conclusions remain unchanged. As part of the plant operation and maintenance regime, permanent staff would be responsible for the management of sub-contractors. Local companies would be approached to provide mainly unskilled and semi-skilled services that would include security, general maintenance and catering.
The 2009 ES identified that operation and maintenance costs There is no anticipated change to the annual operation would be of the order of £27 million per annum, a significant and maintenance costs for the proposed 1,800 MW CCGT proportion of which would benefit the local economy in terms of with peaking plant scheme option. As such the previous employee wages, which would most likely be spent on local assessment conclusions remain unchanged. purchases and local capital expenditure. The 2015 EIR identified that the annual operation and maintenance costs would be proportionately greater than the 1,200 MW scheme, so the benefits to the local economy would be slightly greater.
Some part of DHC2 would be visible from all sides and from a The landscape and visual appraisal (see Section 6.4) large stretches of the surrounding area. However, DHC2 would concludes that the proposed 1,800 MW CCGT with be viewed within the context of the existing Damhead Creek peaking plant scheme option will have no more significant CCGT Power Station and the neighbouring Kingsnorth Power effects than the 1,800 MW CCGT-only scheme option, so Station, located to the south. Therefore, it was not considered there is no change to the impacts views of the area and that DHC2 would cause any impact on the view of the area and it associated tourism effects. is concluded that it would be insignificant to the area’s income from tourism.
Safety would be a key priority during operation of DHC2. As Safety will remain a key priority and there will be no such, there would be no unacceptable risk to public safety in the unacceptable risks to public safety or land uses in the vicinity of the plant or any adverse effect on existing, or area. allocated, land uses in the area.
DHC2 will not conflict with users of neighbouring land. There remains no conflict with users of neighbouring land associated with the 1,800 MW CCGT with peaking plant scheme option.
Cumulative Effects
The 2009 ES assessment considered the potential cumulative The decommissioning of Kingsnorth Power Station (Units effects of DHC2 in conjunction with the proposed supercritical 1-4) has been completed. However the programme for coal fired power station at Kingsnorth Units 5 and 6 and the demolition is scheduled to continue to 2018, according to proposed Kingsnorth Business Park. The cumulative effect of information submitted in support of the Prior Notification for this significant investment in the area was considered to have an Proposed Demolition application submitted to Medway overall positive socio-economic effect. Council. It has therefore been taken into account in the At the time of publication of the 2014 EIR, the development of assessment of cumulative effects.
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1,800 MW CCGT-only scheme option Proposed 1,800 MW CCGT with peaking plant scheme option
Kingsnorth Units 5 and 6 has been shelved, although the Construction of developments within Kingsnorth Business decommissioning of the existing Kingsnorth Power Station (Units Park has commenced. 1-4) was to take place. In summary there is no change to the cumulative socio- The consented Kingsnorth Business Park development would be economic assessment. 66 ha in size, with the ability to accommodate over 2 million sq. ft. of prime industrial floorspace. Infrastructure works had been carried out by the time of the 2014 EIR, to improve access to the site from the A228. Individual units within the consented development had a construction programme of approximately 6- 9 months. Taking the above points into account the investment in the area had decreased from that which was reported in the 2009 ES. As a result, DHC2 was anticipated to be of a greater importance in the industrial development of the area, resulting in a positive socio-economic effect. The 2015 EIR identified that the status of Kingsnorth Power Station Units 5 and 6 remained unchanged from the 2014 EIR, in that the project has been shelved and the decommissioning of Units 1-4 has now commenced. Construction of developments within Kingsnorth Business Park has not yet commenced (although is due to commence shortly). It concluded that there was no change to the cumulative socio-economic assessment.
Mitigation Measures
No mitigation measures or monitoring programmes were No mitigation is required. considered to be necessary due to the high positive socio- economic impact of DHC2 during construction and operation.
6.10.5 Conclusions The construction programme for the proposed 1,800 MW CCGT with peaking plant scheme option is anticipated to have either the same duration of construction phase, or potentially a longer construction phase, depending on the selected approach to construction of the CCGT and OCGT units and whether the OGCT unit would be constructed at the same time as the CCGT units or subsequently. This is not expected to change the number of construction workers required, but may increase the duration of their work. The total investment in the proposed new option would be similar to that of the currently consented 1,800 MW CCGT-only scheme option (approximately £600 - £750 million) and still represents a substation investment for the region. Therefore the overall the conclusions of the previous assessment remain unchanged. ScottishPower are committed to providing employment and training opportunities for the residents of Medway and have agreed a suite of initiatives with Medway Council that will be implemented when the construction phase commences. ScottishPower already own and operate Damhead Creek power station with a number of employees living within the immediate area. Many local businesses have been awarded contracts and continue to secure work across a large range of activities, in relation to both the existing and planned power stations. ScottishPower recognises and supports the economic needs of the communities around the areas that our businesses operate and acknowledge the benefits to both parties. SP are committed to maximise our investment with local companies and increase local business capacity through this project as part of sustaining our own business. In addition, ScottishPower will seek to provide educational and training opportunities, where possible, for people to develop their work related and employability skills through future apprenticeships.
There is no change to the socio-economic assessment of the operational phase as there is no anticipated change to the predicted number of operational and maintenance staff volumes.
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7. Conclusions
An environmental appraisal comparing the anticipated effects of the proposed 1,800 MW CCGT with peaking plant scheme option against the effects of the currently consented 1,800 MW CCGT-only scheme option has been undertaken. A brief summary of the conclusions is provided below. 7.1 Air Quality A dispersion modelling assessment has been undertaken for the proposed 1,800 MW CCGT with peaking plant scheme option to assess the potential effects on residential and ecological receptors in the vicinity of the Site. Agreement was reached with Natural England for the previous section 36 consent variation on that predicted level of impact on the designated ecological receptors – notably the Medway Estuary and Marshes SSSI, SPA and Ramsar site – would not give rise to significant effects and the current proposed variation remains within those agreed levels.
Through use of appropriate stack heights on the CCGT and OCGT units, no significant adverse air quality effects are predicted on human or ecological receptors as a result of the proposed variation, assuming emission levels remain within those to be specified within the Environmental Permit for the installation. 7.2 Noise and Vibration The appraisal of noise and vibration effects has included consideration of residential and ecological receptors, including Medway Estuary and Marshes SSSI, SPA and Ramsar site.
No significant noise and vibration effects are anticipated with the mitigation proposed. Measures will include restrictions on construction working hours, daily as well as seasonal restrictions on impact piling, the implementation of Best Available Techniques (BAT) for control of noise during the design and operation of the scheme, measures to reduce noise at source and noise monitoring in accordance with the previously agreed Noise Management and Monitoring Plan (NMMP)15 approved by the Council on 12 April 2013 under planning reference MC/13/0162 to demonstrate adherence to agreed noise limits at defined monitoring locations. 7.3 Landscape and Visual Amenity The landscape and visual appraisal has been informed by revised photomontages for the eight representative viewpoints assessed previously.
No changes to the conclusions of the previous assessment have been identified. The approved Landscape and Habitat Management Plan16 will be reviewed and updated as necessary to accommodate the proposed 1,800 MW CCGT with peaking plant scheme option. 7.4 Ecology The development footprint will not change and therefore includes main plant development in part of Area 3 as well as Area 1 and the distance to the Medway Estuary and Marshes SSSI, SPA and Ramsar site will remain the same as for the 1,800MW CCGT–only option. The appraisal of ecological effects concludes that the 1,800 MW CCGT with peaking plant scheme option will not have any more significant effects on the designated site or any other ecological receptors to those predicted for the 1,800 MW CCGT-only scheme option. Mitigation measures will be implemented during design, construction and operation, including use of stack heights sufficient to avoid significant adverse air quality effects on designated sites, and the implementation of a Construction Environmnetal Management Plan (CEMP) approved by Medway Council on 23 December 2015 under planning reference MC/15/4047, use of appropriate noise mitigation and the agreed NMMP, and implementation of an approved Landscape and Habitat Management Plan incorporating ecological enhancements.
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7.5 Water Quality No significant changes to the quality or quantity of liquid discharges are anticipated during construction and operation of the proposed 1,800 MW CCGT with peaking plant scheme option. The principles of drainage for DHC2 have previously been approved by Medway Council and will be adopted in the detailed design of this proposed option, in consultation with the Environment Agency. An updated drainage strategy is included with the updated FRA in Appendix I, and is in line with these agreed principles.
Mitigation measures will be implemented to minimise the risk of accidental pollution including use of the CEMP, appropriate bunding of any oil storage tanks and use of oil interceptors where necessary in the drainage system.
In conclusion, no significant effects are predicted for the proposed 1,800 MW CCGT with peaking plant scheme option, as was the case for the currently consented 1,800 MW CCGT-only scheme option. 7.6 Geology, Hydrology and Land Contamination The assessment concludes that there is no change to the previous 2015 EIR conclusions with regards geology, hydrology (including flood risk) and land contamination. An updated FRA, including drainage strategy, is included within Appendix I. 7.7 Traffic and Infrastructure The proposed 1,800 MW CCGT with peaking plant scheme option will not require significant changes to the number of construction staff and associated traffic, although the duration of the construction phase may increase for the with peaking plant option depending on the choice of preferred construction approach. As a result, the conclusion of the construction phase assessment remains as for the 1,800 MW CCGT-only scheme option, with no significant adverse effects on the local road network predicted, with the exception of potential occasional short term disruption and delays caused by a small number of abnormal loads. To mitigate any such disruption, deliveries of such loads will be planned in consultation with the relevant authorities.
During operation, the proposed 1,800 MW CCGT with peaking plant scheme option is unlikely to require any additional staff compared to the 1,800 MW CCGT-only scheme option, so no changes to the assessment of operational traffic impacts are anticipated. 7.8 Cultural Heritage ScottishPower are working to discharge conditions 45 and 46 to the satisfaction of Kent County Council Archaeology and Medway Council by arranging for a suitable additional core sample to be taken from the northern area of interest, undertaking the appropriate reporting and updating the historical records sought by the regulators. Although the 1,800 MW with peaking plant scheme option will extend into Area 3, no additional surveys in this area are necessary in the light of the findings of previous evaluation.
Condition 47 will ensure that any potentially significant finds in Area 1 during construction are notified to the Council, and an appropriate course of action is agreed.
Overall the conclusions of the previous assessment and mitigation measures proposed remain unchanged from the previously consented scheme. 7.9 Socio-Economics The construction of the proposed 1,800 MW CCGT with peaking plant scheme option will require the same numbers staff as the 1,800 MW CCGT-only scheme option, although depending on the preferred construction approach, the duration for which construction workers are required could be longer for the with peaking plant option, if the OCGTs are constructed after the CCGT units. The total investment in the proposed new option would be similar to that of the currently consented 1,800 MW CCGT (approximately £600 - £750 million) and still represents a substantial investment for the region. Therefore the conclusions of the previous assessment remain unchanged.
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There is no change to the socio-economic assessment of the operational phase as there is no anticipated change to the predicted number of operational and maintenance staff volumes. 7.10 Overall In summary, the conclusions of the environmental assessment remain substantially unchanged from those presented for the 1,800 MW CCGT-only option that has been consented, and no additional significant effects have been identified from the proposed 1,800 MW CCGT with peaking plant scheme option. Where required, specific mitigation measures are included in the scheme design and will be implemented should the 1,800 MW CCGT with peaking plant option be progressed.
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FIGURES
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APPENDIX A: PROPOSED SECTION 36 CONSENT VARIATION AND S90 DIRECTION CONSENT NOTICE 2016
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APPENDIX B: CARBON CAPTURE READINESS (CCR) FOOTPRINT REPORT
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APPENDIX C: IMPERIAL COLLEGE, ASSESSMENT OF THE CCR COMPLIANCE OF THE PROPOSED DAMHEAD CREEK 2 1500 MW CCGT + 300 MW OCGT SCHEME
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APPENDIX D: AIR QUALITY TECHNICAL NOTE
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APPENDIX E: COMBINED HEAT AND POWER READINESS (CHP-R) REPORT
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APPENDIX F: NOISE ASSESSMENT
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APPENDIX G: VISUALISATIONS
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APPENDIX H: HABITATS REGULATIONS ASSESSMENT REVIEW 2016
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APPENDIX I: FLOOD RISK ASSESSMENT
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