ABP Southampton. Environmental Statement for Port of Southampton: Berth 201/202 Works. Appendix P. Air Quality Background Information

Transcription

1 ABP Southampton Environmental Statement for Port of Southampton: Berth 201/202 Works Appendix P Air Quality Background Information

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3 Appendix P Air Quality Assessment Background Information

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5 APPENDIX P SUPPORTING AIR QUALITY INFORMATION Section 1 Model Verification Background Concentrations Background concentrations of nitrogen dioxide have been taken from the national maps published by Defra (Defra, 2011). The background concentrations for the diffusion tube locations are presented in Table A1.1. Table A1.1: a Background Concentrations used in the Verification for 2010 a NOx NO Includes all sources. Two values are presented as the study area covers a number of 1km x 1km grid squares. Traffic Data Traffic data used for the 2010 verification are the same as those used for the 2011 modelled scenario. Nitrogen Dioxide Most nitrogen dioxide (NO 2) is produced in the atmosphere by reaction of nitric oxide (NO) with ozone. It is therefore most appropriate to verify the model in terms of primary pollutant emissions of nitrogen oxides (NOx = NO + NO 2). The model has been run to predict the annual mean road-nox, rail-nox and incinerator-nox concentrations during 2010 at the monitoring sites within the study area. The model output of road-nox (i.e. the component of total NOx coming from road traffic) has been compared with the measured road-nox.measured road-nox was calculated from the measured NO 2 concentrations and the adjusted background NO 2 concentration using the NOx from NO 2 calculator available on the Defra LAQM Support website (Defra, 2011). From this the modeled point source and rail NOx was subtracted. A primary adjustment factor was determined as the slope of the best fit line between the measured road contribution and the model derived road contribution, forced through zero (Figure A1.1). This factor was then applied to the modelled road-nox concentration for each receptor to provide adjusted modelled road-nox concentrations. The rail emissions are assumed to be representative of the true emissions and therefore have not been adjusted. The rail-nox and the adjusted road-nox were then summed to determine the total NOx from line sources. The total nitrogen dioxide concentrations were then determined by combining the NOx concentrations from line sources with the predicted background NO 2 concentration within the NOx from NO 2 calculator. It was assumed the NOx to NO 2 relationship for rail emissions is the same as for road emissions. The background concentration entered into the calculator was taken as the sum of the local background concentration and the point source NO 2 concentration (conservatively assumed to be 70% of the predicted annual mean NOx concentration). A secondary adjustment factor was finally calculated as the slope of the best fit line applied to the adjusted data and forced through zero (Figure A1.2). The following primary and secondary adjustment factors have been applied to all modelled nitrogen dioxide data: Primary adjustment factor : Secondary adjustment factor: The results imply that the model was slightly under-predicting the road-nox contribution. This is a common experience with this and most other models. The final NO 2 adjustment is minor. Figure A1.3 compares final adjusted modelled total NO 2 at each of the monitoring sites, to measured total NO 2, and shows a 1:1 relationship.

6 Figure A1.1: Comparison of Measured Road NOx to Unadjusted Modelled Road NOx Concentrations Figure A1.2: Comparison of Measured Total NO2 to Primary Adjusted Modelled Total NO2 Concentrations

7 Figure A1.3: Comparison of Measured Total NO2 to Final Adjusted Modelled Total NO2 Concentrations PM10 and PM2.5 The model has been run to predict annual mean road-pm 10 concentrations during 2010 at Redbridge School. A similar process as used to calculate the road-nox adjustment factor was followed. The measured road-pm 10 and modelled road-pm 10 concentrations are compared to provide the factor for PM 10. The data used to calculate the adjustment factor are provided below: Measured PM 10: 25 µg/m 3 Measured road-pm 10 (measured adjusted background at monitor): = 8.05 µg/m 3 Modelled road-pm 10 = 1.25 µg/m 3 Road-PM 10 adjustment factor: 8.05/1.25 = 6.4 There are no nearby PM 2.5 monitors. It has therefore not been possible to verify the model for PM 2.5. The model outputs of road- PM 2.5 have therefore been adjusted by applying the adjustment factor calculated for road PM 10. Number of Days with PM10 Concentrations > 50 µg/m 3 The number of exceedences of 50 µg/m 3 as a 24-hour mean PM 10 concentration has been calculated from the adjusted-modelled total annual mean concentration following the relationship advised by Defra (2009): A = B /B where A is the number of exceedences of 50 µg/m 3 as a 24-hour mean PM 10 concentration and B is the annual mean PM 10 concentration. The relationship is only applied to annual mean concentrations greater than 16.5 µg/m 3, below this concentration, the number of 24-hour exceedences is assumed to be zero.

8 Section 2 Professional Experience Dr Ben Marner, BSc (Hons) PhD MIEnvSc MIAQM Dr Marner is a Technical Director with AQC, and has more than ten years relevant experience in the field of air quality. He has been responsible for air quality and greenhouse gas assessments of road schemes, rail schemes, airports, power stations, waste incinerators, commercial developments and residential developments in the UK and abroad. He has extensive experience of using detailed dispersion models, as well as contributing to the development of modelling best practices. Dr Marner has arranged and overseen air quality monitoring surveys, as well as contributing to Defra guidance on harmonising monitoring methods. He has been responsible for air quality review and assessments on behalf of numerous local authorities. He has also developed methods to predict nitrogen deposition fluxes on behalf of the Environment Agency, provided support and advice to the UK Government s air quality review and assessment helpdesk, Transport Scotland, Transport for London, and numerous local authorities. Dr Marner has provided public inquiry expert witness services. Penny Wilson, BSc (Hons) MIEnvSc MIAQM Ms Wilson is a Principal Consultant with AQC, with more than ten years relevant experience in the field of air quality. She has been responsible for air quality assessments of a wide range of development projects, covering retail, housing, roads, ports, railways and airports. She has also prepared air quality review and assessment reports and air quality action plans for local authorities and appraised local authority assessments on behalf of the UK governments. Ms Wilson has analysed and interpreted air quality data from the national air quality network and new local authority monitoring, as well as from monitoring of dust. She has also arranged monitoring programmes for PM 10, sulphur dioxide and nitrogen dioxide. Ms Wilson has provided expert witness services for planning appeals. Kiri Brown, BSc (Hons) MSc AMIEnvSc Ms Brown is a Consultant with AQC with over two years relevant experience. She is involved in the preparation of air quality assessments for a range of development projects, including the use of DMRB and ADMS modelling methodologies. She has also been involved in the analysis and interpretation of air quality data, the preparation of Review and Assessment reports for local authorities, and the appraisal of local authority assessments on behalf of the UK governments.

9 Section 3 ADMS 4 Modelling Buildings Input Data Table A3.1: Power Station Buildings Height Dimensions Location (m) X Y Easting Northing Angle Turbine Hall HRSG HRSG Black start gas turbine Raw feed water tank 15 Diameter = 4 m Administration and control building GIS Switchgear Control annex Table A3.2: Incinerator Buildings Height Dimensions Location Angle (m) X Y Easting Northing Dome