Public concern about the fate of toxic contaminants in sewage treatment plants has resulted in a number of regulatory initiatives in North America. These concerns arise from the discharge of contaminants in treated municipal effluents to receiving bodies of water, emissions of volatile air contaminants from aerated processes to the atmosphere. an accumulation of organic and inorganic contaminants in residual solids destined for application on agricultural or recreational land, or other beneficial uses. Toxic chemicals which are present through sewage treatment plants can enter a receiving water body where they can be responsible for lethal or sublethal toxicity to aquatic life. Pesticides such as diazinon and lindane are examples of chemicals which are poorly biodegraded and can potentially cause toxicity to aquatic life forms at extremely low concentrations. The province of Ontario initiated the Municipal-Industrial Strategy for Abatement program with the goal of virtual elimination of the discharge of all toxic chemicals to the environment. In the US., the Clean Water Act and its amendment address the issue of toxics in effluents and sludges.