This page should be read in conjunction with How Plume Plotter Works. It provides more details specific to the Westbury version of Plume Plotter.
Building measurements are taken from .
The image below shows the layout of the stack and building modelled. North is at the top; colours and numbers indicate the height of the buildings and the stack:
These are taken from :
The following values are used for albedo, Bowen ratio and roughness length. Roughness length is as specified in :
The emission rates of pollutants are taken from :
|Oxides of nitrogen||6.161 g|
|Sulphur dioxide||1.54 g|
|Carbon monoxide||2.567 g|
|Hydrogen chloride||308 mg|
|Hydrogen flouride||51 mg|
|Cadmium and Thallium||1.027 mg|
|Other metals||15.4 mg|
|Dioxins and furans||3.08 ng|
The background levels of pollutants are taken from :
concentration per m3
|Oxides of nitrogen||13.19 μg|
|Sulphur dioxide||2.21 μg|
|Carbon monoxide||266 μg|
|Hydrogen chloride||710 ng|
|Hydrogen flouride||2.35 μg|
|Cadmium and Thallium||570 pg|
|Other metals||141.7 ng|
|Dioxins and furans||32.99 fg|
Weather data is taken from METAR reports from a local airport: Bristol.
Upper air data is the latest reported by the Herstmonceux upper air station.
1. Northacre Facility Environmental Statement: Appendix 8.3 - Emissions Modelling. Fichtner. July 2020.
2. Northacre Facility Environmental Statement: Appendix 8.3 - Baseline Analysis. Fichtner. July 2020.