Wastewater treatment, also called sewage treatment, the removal of impurities from wastewater, or sewage, before they reach aquifers or natural bodies of water such as rivers, lakes, estuaries, and oceans. Since pure water is not found in nature (i.e., outside chemical laboratories), any distinction between clean water and polluted water depends on the type and concentration of impurities found in the water as well as on its intended use. In broad terms, water is said to be polluted when it contains enough impurities to make it unfit for a particular use, such as drinking, swimming, or fishing.

Overview:
Waste treatment is the process of treating waste materials to make them less harmful or more suitable for disposal. One common type of waste treatment is sewage treatment, which involves removing contaminants from wastewater before it is released back into the environment.

Sewage Treatment Process:
The sewage treatment process typically involves several stages to remove contaminants and pollutants from wastewater. These stages may include:
- Screening: In this stage, large objects such as sticks and debris are removed from the wastewater.
- Primary Treatment: During primary treatment, solid waste is allowed to settle at the bottom of a tank, while oil and grease float to the top for removal.
- Secondary Treatment: Secondary treatment involves the use of bacteria to break down organic matter in the wastewater.
- Tertiary Treatment: Tertiary treatment is the final stage of sewage treatment, where additional processes such as disinfection or filtration are used to further clean the water.

Importance of Sewage Treatment:
Sewage treatment is essential for protecting public health and the environment. Untreated sewage can contain harmful pathogens and pollutants that can contaminate water sources and cause diseases. By treating sewage before releasing it back into the environment, we can help prevent water pollution and ensure the safety of our water supply.
In conclusion, waste treatment, specifically sewage treatment, plays a crucial role in protecting our environment and public health. By following the sewage treatment process, we can effectively remove contaminants from wastewater and ensure that our water sources remain clean and safe for use.