Details of Plymouth Plume Plotter

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

Stack measurements

These are taken from [1]:

The following values are used for albedo, Bowen ratio and roughness length. Roughness length is as specified in [1]:

Emissions

The emission rates of pollutants are of two types. Both are calculated using the flow rate reported in [1], which is multiplied by the emission concentrations.

For the planned emission rates, the concentrations used are the IED limits, as stated in (e.g.) [1]. Resulting (mass per second) emission rates are listed below:

PollutantEmission rate
per second
Oxides of nitrogen11.2 g
Particulates PM10559 mg
Sulphur dioxide2.79 g
TOC559 mg
Carbon monoxide2.79 g
Hydrogen chloride559 mg
Hydrogen flouride55.9 mg
Ammonia559 mg
Cadmium and thallium2.79 mg
Mercury2.79 mg
Arsenic170 μg
Chromium1.84 mg
Nickel7.6 mg
Other metals27.9 mg
Dioxins and furans5.01 ng
PAH501 μg
PCBs279 μg

The actual emission rates use the same flow rates and the annual average concentrations for 2020, as reported in the incinerator's annual report. They are listed below:

PollutantEmission rate
per second
Oxides of nitrogen9.512 g
Particulates PM105.992 mg
Sulphur dioxide883 mg
TOC21.84 mg
Carbon monoxide249 mg
Hydrogen chloride537 mg
Hydrogen flouride10.36 mg
AmmoniaN/A
Cadmium and thallium48.44 μg
Mercury165.2 μg
ArsenicN/A
ChromiumN/A
NickelN/A
Other metalsN/A
Dioxins and furans173.6 pg
PAHN/A
PCBsN/A

Background levels

The background levels of pollutants are taken from [1]:

PollutantBackground
concentration per m3
Oxides of nitrogen15.3 μg
Particulates PM1013.3 μg
Sulphur dioxide7.1 μg
TOC330 ng
Carbon monoxide134 μg
Hydrogen chloride410 ng
Hydrogen flouride3 ng
Ammonia1 μg
Cadmium and thallium90 pg
Mercury10 pg
Arsenic410 pg
Chromium520 pg
Nickel1.96 ng
Other metals10.68 ng
Dioxins and furans8.5 fg
PAH121 pg
PCBs1.724 ng

Weather data

Wind speed, wind direction, temperature, pressure, and solar radiation are the latest values reported by one of two weather stations. If a value is not available from the primary weather station it is obtained from the secondary weather station. (Some weather stations do not measure solar radiation at all.) The primary weather station is and the secondary weather station is .

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

References

1. Energy from Waste Combined Heat and Power Facility, North Yard, Devonport: Air Quality Dispersion Modelling Report, May 2011.