It is a challenge to encompass the varied subjects that deserve consideration under the heading of environmental biotechnology. Even a definition of environmental technology is difficult. The simplest approach is to define it as the use of biological technologies for sustaining or improving the environment. Bioremediation is practically synonymous with environmental biotechnology. Bioremediation deals with past contamination of the environment and the transformation of pollutants into benign substances. Environmental biotechnology has a future role for continued exploration of new, more easily degradable products and for manufacturing processes that prevent disposal problems. An understanding of ecosystems, thorough knowledge of biological pathways, and the means to measure biological activity are necessary to ensure success for cleaning up past problems and addressing future technologies.