Details of Rivenhall Plume Plotter

This page should be read in conjunction with How Plume Plotter Works. It provides more details specific to the Rivenhall version of Plume Plotter.

Important: the plume plotter only models the CHP emissions. As [1] states, "the exhaust air from the pulp plant, and the AD biofilter will vent to atmosphere via within (sic) the same wind shield as the CHP and gas engines exhaust. Although there will be no combustion gases within the exhaust from the pulp plant or the biofilter, the temperature of the release is much lower than the CHP and will impact upon the buoyancy of the plume". For this reason, the plume plotter tends to underestimate the ground-level pollution.

The stack height of this incinerator has been changed many times, between 35m and 58m (above surrounding ground). This version of the plume plotter assumes a stack height of 35m (again).

Stacks and buildings

Building measurements are taken from [3]. This image shows the layout of the stack and buildings modelled. North is at the top; colours and numbers indicate the height of the buildings and the stack.

Stack measurements

All of these are taken from [3] as modified by [2]:

The following values are used for albedo, Bowen ratio, and roughness length. Roughness length is as specified in [3]:

Emissions

The emission rates of pollutants are taken from [3] as modified by [2]. These are:

PollutantEmission rate
per second
Oxides of nitrogen10.31 g
Sulphur dioxide5.156 g
Carbon monoxide5.156 g
Particulates1.032 g
Hydrogen chloride1.032 g
VOCs1.032 g
Hydrogen flouride104 mg
Ammonia1.032 g
Cadmium and thallium2.062 mg
Mercury5.156 mg
Other metals51.56 mg
Benzo(a)pyrene10.83 μg
Dioxins and furans10.31 ng
PCBs516 μg

Background levels

The background levels of pollutants are taken from [3]. These are:

PollutantBackground
concentration per m3
Oxides of nitrogen18.6 μg
Sulphur dioxide6.2 μg
Carbon monoxide301 μg
Particulates20.2 μg
Hydrogen chloride720 ng
VOCs600 ng
Hydrogen flouride2.35 μg
Ammonia1.8 μg
Cadmium and thallium150 pg
Mercury1.51 ng
Other metals16.51 ng
Benzo(a)pyrene140 pg
Dioxins and furans22.82 fg
PCBs141.5 pg

Weather data

Weather data is taken from METAR reports from a local airport: Stansted.

Upper air data is the latest reported by the Herstmonceux upper air station.

References

1. GENT FAIRHEAD & CO: RIVENHALL DISPERSION MODELLING ASSESSMENT, Fichtner, July 2015.

2. GENT FAIRHEAD RIVENHALL IWMF ENVIRONMENTAL PERMIT VARIATION - SUPPORTING INFORMATION, Fichtner, December 2018.

3. GENT FAIRHEAD & CO: RIVENHALL DISPERSION MODELLING ASSESSMENT, Fichtner, May 2017.