Sewage water, often referred to as wastewater, undergoes a complex treatment process to remove contaminants and make it safe for discharge into the environment or for reuse. Understanding what sewage water is called after treatment is essential for grasping the broader concepts of water management, environmental protection, and public health. This article will explore the various stages of sewage treatment, the terminology used to describe treated sewage, and the implications of these processes on our environment and society.