It is clear that there is a growing need for modeling the
spread of a pollutant in the geosphere and the biosphere. However,
the underlying mechanics are seldom completely understood, and
environmental decision making still relies mainly on case studies.
As a consequence, it is important to use sound mathematical
principles in devising and using a model attempting to
simulate the fate of one or more chemicals through the environment.
This article tries to give an overview over standard issues
of mathematical models for pollution spread. Moreover, 
interconnections with decision support processes are shown which
might greatly increase the effectiveness of the corresponding 
environmental decision making processes.