The Wrexham (Gas Fired Power Station) Order 6.2.8 Volume 2: Environmental Statement Chapter 8: Air quality Planning Act 2008 The Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009 PINS Reference Number: EN010055 Document Reference Number: 6.2.8 Regulation Number: 5(2) (a) Lead Author: Atkins Revision: Date: Description: 0 March 2016 Submission version SEC6-ES Vol1_A4 chapterTabs.indd 9 15/03/2016 10:49 WREXHAM ENERGY CENTRE ENVIRONMENTAL STATEMENT Chapter 8 Air quality INTRODUCTION 8.1 This chapter describes the potential effects of the Wrexham Energy Centre (WEC or Scheme) on ambient (outdoor) air quality. Good air quality is important for human health and the health of other living organisms, both animal and vegetable. The quality of air is determined by the concentration of pollutants it contains, in relation to established health based criteria. A pollutant is essentially a substance in the wrong place, at the wrong time, and at the wrong concentration. Pollution can be more formally defined as the introduction of a substance or form of energy into the environment that is likely to cause damage to the environment or those living within it. 8.2 The air quality assessment contained in this chapter considers the effects of direct and indirect emissions of air pollutants during the construction, operation (including maintenance) and decommissioning phases of the Scheme. Short-term and long- term pollutant concentrations are evaluated in the context of relevant ambient air quality criteria set for the protection of human health and ecology, taking into account where appropriate the existing background situation 8.3 The main element of this air quality assessment is an atmospheric dispersion modelling study of emissions to atmosphere from the Stacks of the Power Station Complex element of the Scheme. This has been carried out in line with national policy and permitting guidance32 to assess the potential effects of changes to ground level concentrations on human health and the environment. Likely significant environmental effects resulting from changes to local air quality due to vehicle movements associated with construction and operational activities have been evaluated and a qualitative assessment of dust emissions from construction and decommissioning evaluated has also been undertaken. Air pollutants 8.4 The assessment of the likely significant environmental effects associated with the Scheme addresses the combustion products discharged in the flue gases from the Stacks, principally oxides of nitrogen (NOx) and carbon monoxide (CO). NOx and CO are the only pollutants with Emission Limit Values (ELVs) in the Industrial Emissions Directive (IED) for natural gas fired CCGT combustion plants (IED Annex V Part 2). 32 Environment Agency/DEFRA (2016) “Air Emissions Risk Assessment for your environmental permit”. Available at https://www.gov.uk/guidance/air-emissions-risk-assessment-for-your-environmental-permit. Horizontal guidance produced by the Environment Agency for permitting is supported by NRW (https://naturalresources.wales/apply-for-a-permit/environmental-permitting-regulations- guidance/horizontal-guidance/?lang=en) 8-1 WREXHAM ENERGY CENTRE ENVIRONMENTAL STATEMENT 8.5 Emissions of NOx from natural gas fired CCGTs are the lowest for any thermal generating plant33. The choice of CCGT technology in itself mitigates air pollution and as such is considered to be embedded mitigation within the design of the Scheme. 8.6 Natural gas contains extremely low levels of sulphur and particulates resulting in 34 negligible emissions of both sulphur dioxide (SO2) and particulate matter (PM) . The natural gas entering turbines is subject to filtration to avoid damage to the equipment and thereby reducing particulate matter in the fuel gas even further. The inherently low emissions of these pollutants from gas fired turbines is reflected in the fact that the European Industrial Emissions Directive (IED) (2010/75/EU) has not specified emission limits for these pollutants for gas fired turbines. As has been agreed during consultation with the regulator and EHO, emissions of these two pollutants are not assessed in the model. 8.7 This approach is supported by National Policy Statement (NPS) EN-2, which states that ‘fossil fuel generating stations are likely to emit nitrogen oxides (NOx) and sulphur oxides (SOx), although SOx emissions from gas-fired generating stations may be negligible.’ 8.8 The air pollutant of most relevance in the context of this assessment is therefore nitrogen dioxide (NO2), a secondary pollutant formed from the oxides of nitrogen which will be discharged from the gas turbines. Road traffic associated with the Scheme will also emit oxides of nitrogen as well as fine particles known as PM10 and PM2.5. These pollutants are the most likely to be present at concentrations close to or above their statutory limit values in areas of the UK, and are hence the focus of the assessment of vehicle emissions associated with the Scheme. 8.9 In addition, dust emissions (including the particles that give rise to soiling, and to human health and ecological effects) may arise during construction and decommissioning of the Scheme, and the effects associated with this are assessed in this chapter of the ES. Key Policies, Legislation and Guidance National Policy Statements Overarching National Policy Statement for Energy (EN-1) 8.10 NPS EN-1 (Section 5.2) requires that applications for new energy infrastructure should consider any significant air emissions, their mitigation and any residual 33 Environment Agency Technical Guidance for Combustion Activities (EPR1.01) available at https://www.gov.uk/government/publications/combustion-activities-additional-guidance 34 http://chp.decc.gov.uk/cms/gas-turbines-10 . 8-2 WREXHAM ENERGY CENTRE ENVIRONMENTAL STATEMENT effects, including taking account of any significant emissions associated with road traffic associated with the development. The assessment should present the predicted absolute emission levels (post mitigation), and report on existing air quality and the relative change in air quality due to the proposed development. Any potential eutrophication impacts (adverse effects on sensitive ecosystems) should also be considered. 8.11 Furthermore, the Environmental Statement (ES) should consider the potential for release of dust emissions, during construction, operation and decommissioning, and recommend measures for preventing or mitigating such emissions (NPS EN-1 Part 5.6). 8.12 NPS EN-1 also highlights the requirement for the assessment of environmental impacts to include cumulative effects of the proposed development when considered with existing pollution sources in and around the Site, and whether these would make the development unacceptable, particularly in relation to statutory environmental quality limits (Part 4, paragraph 4.10.7). National Policy Statement for Fossil Fuel Electricity Generating Infrastructure (EN-2) 8.13 NPS EN-2 sets out specific considerations in relation to air emissions from fossil fuel generating stations, and their regulation through the Environmental Permitting (England and Wales) Regulations 2010 (as amended) ("EPR"). It notes that SOx emissions from gas-fired generating stations may be negligible. National Policy Statement for Gas Supply Infrastructure and Gas and Oil Pipelines (EN-4) 8.14 NPS EN-4 states that the effects of gas emissions should be assessed and advises that applicants should follow the generic considerations on these issues set out in NPS EN-1. Planning Policy Wales (Edition 8, January 2016) 8.15 The land use planning system is integral to improving air quality, and Planning Policy Wales (PPW)35 contains a number of measures to ensure Local Planning Authorities incorporate air quality considerations into planning decisions. 8.16 Paragraph 8.1.9 of PPW states that “Development plan policies and decisions on planning applications should take into account statutory air quality objectives, together with the results of air quality reviews and assessments and any Air Quality Management Plans or Area Action Plans.” 8.17 Paragraph 13.10.3 of PPW states the following in respect of Air Quality Management Areas and improving the quality of air: 35 http://gov.wales/docs/desh/publications/160104planning-policy-wales-edition-8-en.pdf 8-3 WREXHAM ENERGY CENTRE ENVIRONMENTAL STATEMENT “Where pollution considerations, which may be relevant to a pollution control authorisation or licence or result from the need to comply with any statutory environmental quality standards or objectives, affect the use and development of land they can be material planning considerations. This provision extends to air quality objectives set out under Part IV of the Environment Act 1995 and the local authority’s action plans for Air Quality Management Areas […] The weight attached to such considerations will depend on the scope of the pollution control system in each case and the effect on land use and amenity”. 8.18 Paragraph 13.12.1 states further that: “The potential for pollution affecting the use of land will be a material consideration in deciding whether to grant planning permission. Material considerations in determining applications for potentially polluting development are likely to include: location, taking into account such considerations as the reasons for selecting the chosen site itself; impact on health and amenity; the risk and impact of potential pollution from the development, insofar as this might have an effect