Biology of the Wetlands discusses the characteristics and significance of the single- and multi-celled organisms found in wastewater treatment plants and the conditions that support their growth. This knowledge helps operators to make more informed process control decisions. Unlike typical texts written for design and consulting engineers and full of technical jargon, equations, and kinetics, this guide provides the necessary information in a format that is accessible and actionable for plant operators and technicians and helpful to others involved in wastewater treatment.