Contaminated Land Air Quality Environmental Audit Partnership No: OC 00776 PROPOSED ENERGY GENERATION FACILITY, LEGACY, WREXHAM AIR QUALITY ASSESSMENT for: Harbour Energy Ltd / AXIS April 2020 R2746C-R01-v3 Smith Grant LLP, Station House, Station Road, Ruabon, Wrexham, LL14 6DL web: www.smithgrant.co.uk Members: K E Hawkins (Chairman), B J Thomas, A F Smith, D Wayland Proposed Energy Generation Facility, Legacy 2 Air Quality Assessment DOCUMENT CONTROL SHEET Report Title: Proposed Energy Generation Facility, Legacy, Wrexham Air Quality Assessment Client: Harbour Energy Limited / Axis Report Reference Number: R2746C-R01 Report Status: Final Version: v3 Report Date: April 2020 for: Smith Grant LLP Name Position Signature Date K Hawkins Consultant Drafted by BSc MSc MIAQM CEnv 07.04.20 K Hawkins Chairman Checked BSc MSc MIAQM CEnv 07.04.20 Document Revision Record: Version Report Status Date Details of Revision v1 Draft 11.03.20 Draft for client review v2 Revised Draft 23.03.20 Revised draft for client review; incorporating amendments to ecological assessment v3 Final 07.04.20 Final; no edits to revised draft This report has been prepared by Smith Grant LLP for the sole and exclusive use of Harbour Energy Limited and Axis P.E.D. Ltd. Reasonable skill, care and diligence has been exercised within the terms of the contract with the client. We disclaim any responsibility to the client and others in respect of any matters outside the scope of the above. This report may be relied upon or transferred to any other parties only with the express written authorization of Smith Grant LLP, such consent not to be unreasonably withheld or delayed. If any Third Party comes into possession of this report, they rely on it at their own risk and the authors owe them no duty or care of skill. Smith Grant LLP reserves the right to alter any of the foregoing information in the event of new information being disclosed or provided and in the light of changes to legislation, guidelines and responses by the statutory and regulatory authorities. Smith Grant LLP R2746C-R01-v3 Environmental Consultancy 07.04.2020 Proposed Energy Generation Facility, Legacy 3 Air Quality Assessment PROPOSED ENERGY GENERATION FACILITY, LEGACY, WREXHAM AIR QUALITY ASSESSMENT For: Harbour Energy Limited / Axis Contents 1 Introduction 2 Technical and Legislative Context 3 Assessment Methodology 4 Site Location and Proposed Development 5 Site Setting and Baseline Conditions 6 Assessment – Model Setup 7 Assessment – Human Health 8 Assessment – Ecological Impacts 9 Conclusions Appendices A Proposed Development Site Location Plans B Background Air Quality Data and Modelled Receptor Information C Gas Engine Datasheets D Stack Emission Model Outputs – NO2 Contour Plots: Human health Assessment E Stack Emission Model Outputs – NOx Contour Plots: Ecological Assessment F Stack Emission Model Outputs – Results Smith Grant LLP R2746C-R01-v3 Environmental Consultancy 07.04.2020 Proposed Energy Generation Facility, Legacy 4 Air Quality Assessment EXECUTIVE SUMMARY Site Location The site comprises an area of undeveloped land located within the wider area of the National Grid Electricity Sub-Station at Legacy near Wrexham. The site lies within the administrative area of Wrexham County Borough Council (WCBC). Proposed Site Use Proposals are for installation of up to eleven gas engine containers, and associated infrastructure, with a combined electrical output of up to 49.9 MWe. Each engine is to be served by an individual stack of 12m height. The facility is expected to operate up to a maximum of 2,500 hours per annum. The facility would be operated in accordance with an Environmental Permit to be issued by Natural Resources Wales. Scope of Works / An Air Quality Assessment (AQA) has been undertaken to assess the potential Objectives of Study impacts of aerial emissions from the proposed operations on local receptors and to inform the planning application. The AQA included a review of background air quality information, establishment of the local site setting and a review of technical data relating to the proposals. Atmospheric dispersion modelling has been undertaken of the potential engine stack emissions (in the form of NOx, NO2 and CO) to enable assessment of the potential impacts of the stack emissions on nearby human health and ecological receptors. The assessment has been undertaken in accordance with relevant guidance provided by the Institute of Air Quality Management (IAQM) and Natural Resources Wales / Environment Agency (EA) in relation to planning, environmental permitting and air quality. Site Setting The site is located within the northern area of the curtilage of the existing electrical sub-station, in a predominantly rural area, surrounded by open fields and scattered residential housing. The nearest existing residential development lies about 380m to the southwest of the site with other properties within 500m to the northeast and southeast. Background Air Quality Reference has been made to both WCBC air quality monitoring data and information provided by Defra to inform the likely local background air quality. Concentrations of NOx, NO2 and CO in the immediate area and at nearby relevant receptors are expected to be well below established long-term and short-term Air Quality Assessment Levels (AQALs). WCBC has not declared any AQMAs within its administrative area. A stretch of the A483, lying about 3.8km to the northeast of the site, has been identified by the Welsh Government as failing to meet the EU annual mean NO2 limit value and is currently subject air quality mitigation measures. This area has not been declared an AQMA by WCBC. Smith Grant LLP R2746C-R01-v3 Environmental Consultancy 07.04.2020 Proposed Energy Generation Facility, Legacy 5 Air Quality Assessment Conclusions and The assessment has considered the potential changes in pollutant concentrations Recommendations at relevant receptors due to the proposed development and the resulting total concentrations. Greatest impacts are predicted at those residential receptors closest to the site to the northeast, southwest and southeast. Background pollutant concentrations at these locations are expected to be well below the AQALs, and the assessment does not predict the proposed development to result in total long-term NO2 concentrations here to approach, or exceed, the relevant AQALs. Predicted short-term total concentrations at the nearest residential receptors are predicted to remain well below the AQAL. The assessment has also included consideration of the nearby footpaths although any exposure here would be transient and the AQAL does not specifically apply. All predicted total concentrations remain well below the AQAL. The assessment of ecological impacts has comprised a Critical level and Critical Load assessment, where relevant Critical Load information is available. It is concluded that the Proposed Development would not result in likely significant effects at any of the international designated sites. Predicted long-term ambient NOx, nitrogen deposition and acid deposition PCs at the Legacy Sub-station LWS are all below the relevant screening thresholds. The short-term ambient NOx PCs and PECs are above the screening thresholds at the nearest parts of the LWS. The long-term effects of ambient NOx on vegetation are more significant than short-term and no statutory AQAL is established. Exceedance of the AQAL does not therefore infer that the Proposed Development would result in significant pollution. But this would require further consideration and assessment by an ecologist. Smith Grant LLP R2746C-R01-v3 Environmental Consultancy 07.04.2020 Proposed Energy Generation Facility, Legacy 6 Air Quality Assessment Introduction 1.1 General 1.1.1 Harbour Energy Limited (‘HEL’) proposes to submit a planning application to the Planning Inspectorate Wales (‘the Inspectorate’) for the installation of a series of gas engines on an area of land at the Legacy 400 kV electricity sub-station, near Wrexham. The Proposed Development would comprise up to eleven gas engines to provide up to 49.9MWe of power to the National Grid. As the Proposed Development forms an energy generation facility in the 10-350MWe range it forms a Development of National Significance (DNS). 1.1.2 Axis, acting on behalf of HEL, instructed Smith Grant LLP (‘SGP’) to undertake an Air Quality Assessment of the proposed development (AQA). The following report is provided for submission with the pre-application Screening Report that is to be submitted to the Inspectorate. 1.1.3 The development would be located within the wider curtilage of the sub-station and land owned by National Grid. In this following report the term ‘site’ is used to refer to the area of land subject to the proposed development and which forms the subject of the planning application. The site lies within the administrative area of Wrexham County Borough Council (WCBC). 1.2 Scope and Objectives of the Report 1.2.1 The following report describes the AQA undertaken by SGP in accordance with the brief agreed with the client. The assessment considers the potential impacts of aerial emissions from the proposed operations on local receptors. The methodology follows the framework described in the IAQM: Land Use Planning and Development Control: Planning for Air1, 2 and, where applicable, Defra / Environment Agency (EA) Air Emissions Environmental Risk Assessment Guidance for environmental permitting facilities3. 1.2.2 The report describes the methods used to assess the impacts, the baseline