Water treatment is, collectively, the industrial scale processes that makes water more acceptable for an end use, which may be drinking, industry, or medicine. Water treatment is unlike small-scale water sterilization that campers and other people in wilderness areas practice. Water treatment should remove existing water contaminants or so reduce their concentration that their water becomes fit for its desired end-use, which may be safely returning used water to the environment.
The processes involved in treating water for drinking purposes to provide a safe source of water supply may be solids separation using physical processes such as settling and filtration, and chemical processes such as disinfection and coagulation.
For most people, the term “water treatment” refers to potable water production from raw water, whereas “waste water treatment” refers to the treatment of polluted water, where the pollution could be from human waste, industry, agricultural waste or other sources of pollution.