Dispersion modelling is required for most IPC/IPPC applications. Computer
models are able to estimate the environmental concentrations of emissions
to air from many types of source (eg stacks, roads, landfill sites, accidental
releases). All modelling of this nature has a degree of uncertainty; ADM
is able to offer considerable experience in both modelling and assessment
of the uncertainties of modelling predictions. The figure shows an example
of the output from a dispersion model in terms of impact to ground level
concentrations resulting from a new waste-to-energy plant, including the
effects of nearby buildings, terrain and the time varying nature of emissions
throughout the year.
For some of our clients computer based dispersion models cannot provide
the answer or the degree of certainty required. In these circumstances physical
modelling
in a wind tunnel can provide a solution. One of ADM's senior staff, David
Harvey, worked at BMT Fluid Mechanics for 5 years undertaking many wind
tunnel studies and so he has a thorough understanding of the strengths and
limitations of the technique. ADM have specified and managed wind tunnel
studies on behalf of its clients.
As part of the review of major industry the Environment Agency occasionally
require the impact of a source of air pollution or several plants to be
determined in terms of the deposition of sulphur and nitrogen oxides. This
deposition is harmful in some places where the ecosystems are sensitive.
In order to determine the impact it is necessary to map the impacts onto
the various ecosystems and compare the existing deposition plus the contribution
from the source to what the ecosystem can tolerate (ie the critical load).
It is then possible to produce maps of the areas where critical loads are
exceeded and to investigate the effects of various emissions control strategies
in relation to this.
ADM undertook, in collaboration with Foster Wheeler, a detailed study into
sulphur dioxide abatement at two large power stations in the north of England
for Edison First Power Limited.
