The Cornwall plume plotter shows a prediction of the current amount of air pollution (at ground level) caused by emissions from the incinerator at St Dennis.

Plume Plotter predicts this fallout using AERMOD, which is one of the most widely used modelling systems for air pollution. It uses the latest local weather conditions and upper air data, which are obtained in real time. Plume Plotter does not use real-time information about the incinerator's emissions. Instead, it assumes that the incinerator is operating continuously (8760 hours per year) and emitting pollutants at a constant rate. The emission rates assumed are either:

• the long-term planned emission rates that were specified by the incinerator developers in their planning application;
• the average actual emission rates for a recent year, as measured and reported by the incinerator operators.

The user can select either planned or actual emission rates when using the plume plotter.

The other parameters (e.g. emission velocity and temperature) used are also taken directly from the planning application.

In the real world, the incinerator's emissions at any point in time might be greater or less than we assume, or it may be shut down completely. Ideally, Plume Plotter would use real-time, hourly, information about the incinerator's emissions. However, this is impossible because incinerator operators do not publish data about their emissions in real time. Some information is published retrospectively (e.g. average emission concentrations of some pollutants), some is never published (e.g. emission velocity and temperature), and some emissions are not continuously monitored (e.g. emission concentrations of dioxins).

Plume Plotter's model takes account of the real terrain in the vicinity of the incinerator and the shape of the incinerator buildings.

For detailed information, please see the links below.

Disclaimer: While we believe that our predictions are as accurate as possible using the resources and information available to us, we make no claims or guarantees made about the correctness of the information presented on this website.